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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E X P _ C H 4 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Checks; use Checks; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Aggr; use Exp_Aggr; with Exp_Atag; use Exp_Atag; with Exp_Ch2; use Exp_Ch2; with Exp_Ch3; use Exp_Ch3; with Exp_Ch6; use Exp_Ch6; with Exp_Ch7; use Exp_Ch7; with Exp_Ch9; use Exp_Ch9; with Exp_Disp; use Exp_Disp; with Exp_Fixd; use Exp_Fixd; with Exp_Intr; use Exp_Intr; with Exp_Pakd; use Exp_Pakd; with Exp_Tss; use Exp_Tss; with Exp_Util; use Exp_Util; with Exp_VFpt; use Exp_VFpt; with Freeze; use Freeze; with Inline; use Inline; with Lib; use Lib; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Par_SCO; use Par_SCO; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Cat; use Sem_Cat; with Sem_Ch3; use Sem_Ch3; with Sem_Ch8; use Sem_Ch8; with Sem_Ch13; use Sem_Ch13; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Type; use Sem_Type; with Sem_Util; use Sem_Util; with Sem_Warn; use Sem_Warn; with Sinfo; use Sinfo; with Snames; use Snames; with Stand; use Stand; with SCIL_LL; use SCIL_LL; with Targparm; use Targparm; with Tbuild; use Tbuild; with Ttypes; use Ttypes; with Uintp; use Uintp; with Urealp; use Urealp; with Validsw; use Validsw; package body Exp_Ch4 is ----------------------- -- Local Subprograms -- ----------------------- procedure Binary_Op_Validity_Checks (N : Node_Id); pragma Inline (Binary_Op_Validity_Checks); -- Performs validity checks for a binary operator procedure Build_Boolean_Array_Proc_Call (N : Node_Id; Op1 : Node_Id; Op2 : Node_Id); -- If a boolean array assignment can be done in place, build call to -- corresponding library procedure. function Current_Anonymous_Master return Entity_Id; -- Return the entity of the heterogeneous finalization master belonging to -- the current unit (either function, package or procedure). This master -- services all anonymous access-to-controlled types. If the current unit -- does not have such master, create one. procedure Displace_Allocator_Pointer (N : Node_Id); -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and -- Expand_Allocator_Expression. Allocating class-wide interface objects -- this routine displaces the pointer to the allocated object to reference -- the component referencing the corresponding secondary dispatch table. procedure Expand_Allocator_Expression (N : Node_Id); -- Subsidiary to Expand_N_Allocator, for the case when the expression -- is a qualified expression or an aggregate. procedure Expand_Array_Comparison (N : Node_Id); -- This routine handles expansion of the comparison operators (N_Op_Lt, -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic -- code for these operators is similar, differing only in the details of -- the actual comparison call that is made. Special processing (call a -- run-time routine) function Expand_Array_Equality (Nod : Node_Id; Lhs : Node_Id; Rhs : Node_Id; Bodies : List_Id; Typ : Entity_Id) return Node_Id; -- Expand an array equality into a call to a function implementing this -- equality, and a call to it. Loc is the location for the generated nodes. -- Lhs and Rhs are the array expressions to be compared. Bodies is a list -- on which to attach bodies of local functions that are created in the -- process. It is the responsibility of the caller to insert those bodies -- at the right place. Nod provides the Sloc value for the generated code. -- Normally the types used for the generated equality routine are taken -- from Lhs and Rhs. However, in some situations of generated code, the -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies -- the type to be used for the formal parameters. procedure Expand_Boolean_Operator (N : Node_Id); -- Common expansion processing for Boolean operators (And, Or, Xor) for the -- case of array type arguments. procedure Expand_Short_Circuit_Operator (N : Node_Id); -- Common expansion processing for short-circuit boolean operators function Expand_Composite_Equality (Nod : Node_Id; Typ : Entity_Id; Lhs : Node_Id; Rhs : Node_Id; Bodies : List_Id) return Node_Id; -- Local recursive function used to expand equality for nested composite -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which -- to attach bodies of local functions that are created in the process. -- This is the responsibility of the caller to insert those bodies at the -- right place. Nod provides the Sloc value for generated code. Lhs and Rhs -- are the left and right sides for the comparison, and Typ is the type of -- the arrays to compare. procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id); -- Routine to expand concatenation of a sequence of two or more operands -- (in the list Operands) and replace node Cnode with the result of the -- concatenation. The operands can be of any appropriate type, and can -- include both arrays and singleton elements. procedure Fixup_Universal_Fixed_Operation (N : Node_Id); -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal -- fixed. We do not have such a type at runtime, so the purpose of this -- routine is to find the real type by looking up the tree. We also -- determine if the operation must be rounded. function Has_Inferable_Discriminants (N : Node_Id) return Boolean; -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable -- discriminants if it has a constrained nominal type, unless the object -- is a component of an enclosing Unchecked_Union object that is subject -- to a per-object constraint and the enclosing object lacks inferable -- discriminants. -- -- An expression of an Unchecked_Union type has inferable discriminants -- if it is either a name of an object with inferable discriminants or a -- qualified expression whose subtype mark denotes a constrained subtype. procedure Insert_Dereference_Action (N : Node_Id); -- N is an expression whose type is an access. When the type of the -- associated storage pool is derived from Checked_Pool, generate a -- call to the 'Dereference' primitive operation. function Make_Array_Comparison_Op (Typ : Entity_Id; Nod : Node_Id) return Node_Id; -- Comparisons between arrays are expanded in line. This function produces -- the body of the implementation of (a > b), where a and b are one- -- dimensional arrays of some discrete type. The original node is then -- expanded into the appropriate call to this function. Nod provides the -- Sloc value for the generated code. function Make_Boolean_Array_Op (Typ : Entity_Id; N : Node_Id) return Node_Id; -- Boolean operations on boolean arrays are expanded in line. This function -- produce the body for the node N, which is (a and b), (a or b), or (a xor -- b). It is used only the normal case and not the packed case. The type -- involved, Typ, is the Boolean array type, and the logical operations in -- the body are simple boolean operations. Note that Typ is always a -- constrained type (the caller has ensured this by using -- Convert_To_Actual_Subtype if necessary). procedure Optimize_Length_Comparison (N : Node_Id); -- Given an expression, if it is of the form X'Length op N (or the other -- way round), where N is known at compile time to be 0 or 1, and X is a -- simple entity, and op is a comparison operator, optimizes it into a -- comparison of First and Last. procedure Rewrite_Comparison (N : Node_Id); -- If N is the node for a comparison whose outcome can be determined at -- compile time, then the node N can be rewritten with True or False. If -- the outcome cannot be determined at compile time, the call has no -- effect. If N is a type conversion, then this processing is applied to -- its expression. If N is neither comparison nor a type conversion, the -- call has no effect. procedure Tagged_Membership (N : Node_Id; SCIL_Node : out Node_Id; Result : out Node_Id); -- Construct the expression corresponding to the tagged membership test. -- Deals with a second operand being (or not) a class-wide type. function Safe_In_Place_Array_Op (Lhs : Node_Id; Op1 : Node_Id; Op2 : Node_Id) return Boolean; -- In the context of an assignment, where the right-hand side is a boolean -- operation on arrays, check whether operation can be performed in place. procedure Unary_Op_Validity_Checks (N : Node_Id); pragma Inline (Unary_Op_Validity_Checks); -- Performs validity checks for a unary operator ------------------------------- -- Binary_Op_Validity_Checks -- ------------------------------- procedure Binary_Op_Validity_Checks (N : Node_Id) is begin if Validity_Checks_On and Validity_Check_Operands then Ensure_Valid (Left_Opnd (N)); Ensure_Valid (Right_Opnd (N)); end if; end Binary_Op_Validity_Checks; ------------------------------------ -- Build_Boolean_Array_Proc_Call -- ------------------------------------ procedure Build_Boolean_Array_Proc_Call (N : Node_Id; Op1 : Node_Id; Op2 : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Kind : constant Node_Kind := Nkind (Expression (N)); Target : constant Node_Id := Make_Attribute_Reference (Loc, Prefix => Name (N), Attribute_Name => Name_Address); Arg1 : Node_Id := Op1; Arg2 : Node_Id := Op2; Call_Node : Node_Id; Proc_Name : Entity_Id; begin if Kind = N_Op_Not then if Nkind (Op1) in N_Binary_Op then -- Use negated version of the binary operators if Nkind (Op1) = N_Op_And then Proc_Name := RTE (RE_Vector_Nand); elsif Nkind (Op1) = N_Op_Or then Proc_Name := RTE (RE_Vector_Nor); else pragma Assert (Nkind (Op1) = N_Op_Xor); Proc_Name := RTE (RE_Vector_Xor); end if; Call_Node := Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Name, Loc), Parameter_Associations => New_List ( Target, Make_Attribute_Reference (Loc, Prefix => Left_Opnd (Op1), Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Right_Opnd (Op1), Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Left_Opnd (Op1), Attribute_Name => Name_Length))); else Proc_Name := RTE (RE_Vector_Not); Call_Node := Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Name, Loc), Parameter_Associations => New_List ( Target, Make_Attribute_Reference (Loc, Prefix => Op1, Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Op1, Attribute_Name => Name_Length))); end if; else -- We use the following equivalences: -- (not X) or (not Y) = not (X and Y) = Nand (X, Y) -- (not X) and (not Y) = not (X or Y) = Nor (X, Y) -- (not X) xor (not Y) = X xor Y -- X xor (not Y) = not (X xor Y) = Nxor (X, Y) if Nkind (Op1) = N_Op_Not then Arg1 := Right_Opnd (Op1); Arg2 := Right_Opnd (Op2); if Kind = N_Op_And then Proc_Name := RTE (RE_Vector_Nor); elsif Kind = N_Op_Or then Proc_Name := RTE (RE_Vector_Nand); else Proc_Name := RTE (RE_Vector_Xor); end if; else if Kind = N_Op_And then Proc_Name := RTE (RE_Vector_And); elsif Kind = N_Op_Or then Proc_Name := RTE (RE_Vector_Or); elsif Nkind (Op2) = N_Op_Not then Proc_Name := RTE (RE_Vector_Nxor); Arg2 := Right_Opnd (Op2); else Proc_Name := RTE (RE_Vector_Xor); end if; end if; Call_Node := Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Proc_Name, Loc), Parameter_Associations => New_List ( Target, Make_Attribute_Reference (Loc, Prefix => Arg1, Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Arg2, Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Arg1, Attribute_Name => Name_Length))); end if; Rewrite (N, Call_Node); Analyze (N); exception when RE_Not_Available => return; end Build_Boolean_Array_Proc_Call; ------------------------------ -- Current_Anonymous_Master -- ------------------------------ function Current_Anonymous_Master return Entity_Id is Decls : List_Id; Loc : Source_Ptr; Subp_Body : Node_Id; Unit_Decl : Node_Id; Unit_Id : Entity_Id; begin Unit_Id := Cunit_Entity (Current_Sem_Unit); -- Find the entity of the current unit if Ekind (Unit_Id) = E_Subprogram_Body then -- When processing subprogram bodies, the proper scope is always that -- of the spec. Subp_Body := Unit_Id; while Present (Subp_Body) and then Nkind (Subp_Body) /= N_Subprogram_Body loop Subp_Body := Parent (Subp_Body); end loop; Unit_Id := Corresponding_Spec (Subp_Body); end if; Loc := Sloc (Unit_Id); Unit_Decl := Unit (Cunit (Current_Sem_Unit)); -- Find the declarations list of the current unit if Nkind (Unit_Decl) = N_Package_Declaration then Unit_Decl := Specification (Unit_Decl); Decls := Visible_Declarations (Unit_Decl); if No (Decls) then Decls := New_List (Make_Null_Statement (Loc)); Set_Visible_Declarations (Unit_Decl, Decls); elsif Is_Empty_List (Decls) then Append_To (Decls, Make_Null_Statement (Loc)); end if; else Decls := Declarations (Unit_Decl); if No (Decls) then Decls := New_List (Make_Null_Statement (Loc)); Set_Declarations (Unit_Decl, Decls); elsif Is_Empty_List (Decls) then Append_To (Decls, Make_Null_Statement (Loc)); end if; end if; -- The current unit has an existing anonymous master, traverse its -- declarations and locate the entity. if Has_Anonymous_Master (Unit_Id) then declare Decl : Node_Id; Fin_Mas_Id : Entity_Id; begin Decl := First (Decls); while Present (Decl) loop -- Look for the first variable in the declarations whole type -- is Finalization_Master. if Nkind (Decl) = N_Object_Declaration then Fin_Mas_Id := Defining_Identifier (Decl); if Ekind (Fin_Mas_Id) = E_Variable and then Etype (Fin_Mas_Id) = RTE (RE_Finalization_Master) then return Fin_Mas_Id; end if; end if; Next (Decl); end loop; -- The master was not found even though the unit was labeled as -- having one. raise Program_Error; end; -- Create a new anonymous master else declare First_Decl : constant Node_Id := First (Decls); Action : Node_Id; Fin_Mas_Id : Entity_Id; begin -- Since the master and its associated initialization is inserted -- at top level, use the scope of the unit when analyzing. Push_Scope (Unit_Id); -- Create the finalization master Fin_Mas_Id := Make_Defining_Identifier (Loc, Chars => New_External_Name (Chars (Unit_Id), "AM")); -- Generate: -- <Fin_Mas_Id> : Finalization_Master; Action := Make_Object_Declaration (Loc, Defining_Identifier => Fin_Mas_Id, Object_Definition => New_Reference_To (RTE (RE_Finalization_Master), Loc)); Insert_Before_And_Analyze (First_Decl, Action); -- Mark the unit to prevent the generation of multiple masters Set_Has_Anonymous_Master (Unit_Id); -- Do not set the base pool and mode of operation on .NET/JVM -- since those targets do not support pools and all VM masters -- are heterogeneous by default. if VM_Target = No_VM then -- Generate: -- Set_Base_Pool -- (<Fin_Mas_Id>, Global_Pool_Object'Unrestricted_Access); Action := Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Set_Base_Pool), Loc), Parameter_Associations => New_List ( New_Reference_To (Fin_Mas_Id, Loc), Make_Attribute_Reference (Loc, Prefix => New_Reference_To (RTE (RE_Global_Pool_Object), Loc), Attribute_Name => Name_Unrestricted_Access))); Insert_Before_And_Analyze (First_Decl, Action); -- Generate: -- Set_Is_Heterogeneous (<Fin_Mas_Id>); Action := Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Set_Is_Heterogeneous), Loc), Parameter_Associations => New_List ( New_Reference_To (Fin_Mas_Id, Loc))); Insert_Before_And_Analyze (First_Decl, Action); end if; -- Restore the original state of the scope stack Pop_Scope; return Fin_Mas_Id; end; end if; end Current_Anonymous_Master; -------------------------------- -- Displace_Allocator_Pointer -- -------------------------------- procedure Displace_Allocator_Pointer (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Orig_Node : constant Node_Id := Original_Node (N); Dtyp : Entity_Id; Etyp : Entity_Id; PtrT : Entity_Id; begin -- Do nothing in case of VM targets: the virtual machine will handle -- interfaces directly. if not Tagged_Type_Expansion then return; end if; pragma Assert (Nkind (N) = N_Identifier and then Nkind (Orig_Node) = N_Allocator); PtrT := Etype (Orig_Node); Dtyp := Available_View (Designated_Type (PtrT)); Etyp := Etype (Expression (Orig_Node)); if Is_Class_Wide_Type (Dtyp) and then Is_Interface (Dtyp) then -- If the type of the allocator expression is not an interface type -- we can generate code to reference the record component containing -- the pointer to the secondary dispatch table. if not Is_Interface (Etyp) then declare Saved_Typ : constant Entity_Id := Etype (Orig_Node); begin -- 1) Get access to the allocated object Rewrite (N, Make_Explicit_Dereference (Loc, Relocate_Node (N))); Set_Etype (N, Etyp); Set_Analyzed (N); -- 2) Add the conversion to displace the pointer to reference -- the secondary dispatch table. Rewrite (N, Convert_To (Dtyp, Relocate_Node (N))); Analyze_And_Resolve (N, Dtyp); -- 3) The 'access to the secondary dispatch table will be used -- as the value returned by the allocator. Rewrite (N, Make_Attribute_Reference (Loc, Prefix => Relocate_Node (N), Attribute_Name => Name_Access)); Set_Etype (N, Saved_Typ); Set_Analyzed (N); end; -- If the type of the allocator expression is an interface type we -- generate a run-time call to displace "this" to reference the -- component containing the pointer to the secondary dispatch table -- or else raise Constraint_Error if the actual object does not -- implement the target interface. This case corresponds with the -- following example: -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is -- begin -- return new Iface_2'Class'(Obj); -- end Op; else Rewrite (N, Unchecked_Convert_To (PtrT, Make_Function_Call (Loc, Name => New_Reference_To (RTE (RE_Displace), Loc), Parameter_Associations => New_List ( Unchecked_Convert_To (RTE (RE_Address), Relocate_Node (N)), New_Occurrence_Of (Elists.Node (First_Elmt (Access_Disp_Table (Etype (Base_Type (Dtyp))))), Loc))))); Analyze_And_Resolve (N, PtrT); end if; end if; end Displace_Allocator_Pointer; --------------------------------- -- Expand_Allocator_Expression -- --------------------------------- procedure Expand_Allocator_Expression (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Exp : constant Node_Id := Expression (Expression (N)); PtrT : constant Entity_Id := Etype (N); DesigT : constant Entity_Id := Designated_Type (PtrT); procedure Apply_Accessibility_Check (Ref : Node_Id; Built_In_Place : Boolean := False); -- Ada 2005 (AI-344): For an allocator with a class-wide designated -- type, generate an accessibility check to verify that the level of the -- type of the created object is not deeper than the level of the access -- type. If the type of the qualified expression is class- wide, then -- always generate the check (except in the case where it is known to be -- unnecessary, see comment below). Otherwise, only generate the check -- if the level of the qualified expression type is statically deeper -- than the access type. -- -- Although the static accessibility will generally have been performed -- as a legality check, it won't have been done in cases where the -- allocator appears in generic body, so a run-time check is needed in -- general. One special case is when the access type is declared in the -- same scope as the class-wide allocator, in which case the check can -- never fail, so it need not be generated. -- -- As an open issue, there seem to be cases where the static level -- associated with the class-wide object's underlying type is not -- sufficient to perform the proper accessibility check, such as for -- allocators in nested subprograms or accept statements initialized by -- class-wide formals when the actual originates outside at a deeper -- static level. The nested subprogram case might require passing -- accessibility levels along with class-wide parameters, and the task -- case seems to be an actual gap in the language rules that needs to -- be fixed by the ARG. ??? ------------------------------- -- Apply_Accessibility_Check -- ------------------------------- procedure Apply_Accessibility_Check (Ref : Node_Id; Built_In_Place : Boolean := False) is New_Node : Node_Id; begin if Ada_Version >= Ada_2005 and then Is_Class_Wide_Type (DesigT) and then not Scope_Suppress (Accessibility_Check) and then (Type_Access_Level (Etype (Exp)) > Type_Access_Level (PtrT) or else (Is_Class_Wide_Type (Etype (Exp)) and then Scope (PtrT) /= Current_Scope)) then -- If the allocator was built in place Ref is already a reference -- to the access object initialized to the result of the allocator -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). Otherwise -- it is the entity associated with the object containing the -- address of the allocated object. if Built_In_Place then New_Node := New_Copy (Ref); else New_Node := New_Reference_To (Ref, Loc); end if; New_Node := Make_Attribute_Reference (Loc, Prefix => New_Node, Attribute_Name => Name_Tag); if Tagged_Type_Expansion then New_Node := Build_Get_Access_Level (Loc, New_Node); elsif VM_Target /= No_VM then New_Node := Make_Function_Call (Loc, Name => New_Reference_To (RTE (RE_Get_Access_Level), Loc), Parameter_Associations => New_List (New_Node)); -- Cannot generate the runtime check else return; end if; Insert_Action (N, Make_Raise_Program_Error (Loc, Condition => Make_Op_Gt (Loc, Left_Opnd => New_Node, Right_Opnd => Make_Integer_Literal (Loc, Type_Access_Level (PtrT))), Reason => PE_Accessibility_Check_Failed)); end if; end Apply_Accessibility_Check; -- Local variables Aggr_In_Place : constant Boolean := Is_Delayed_Aggregate (Exp); Indic : constant Node_Id := Subtype_Mark (Expression (N)); T : constant Entity_Id := Entity (Indic); Node : Node_Id; Tag_Assign : Node_Id; Temp : Entity_Id; Temp_Decl : Node_Id; TagT : Entity_Id := Empty; -- Type used as source for tag assignment TagR : Node_Id := Empty; -- Target reference for tag assignment -- Start of processing for Expand_Allocator_Expression begin -- In the case of an Ada 2012 allocator whose initial value comes from a -- function call, pass "the accessibility level determined by the point -- of call" (AI05-0234) to the function. Conceptually, this belongs in -- Expand_Call but it couldn't be done there (because the Etype of the -- allocator wasn't set then) so we generate the parameter here. See -- the Boolean variable Defer in (a block within) Expand_Call. if Ada_Version >= Ada_2012 and then Nkind (Exp) = N_Function_Call then declare Subp : Entity_Id; begin if Nkind (Name (Exp)) = N_Explicit_Dereference then Subp := Designated_Type (Etype (Prefix (Name (Exp)))); else Subp := Entity (Name (Exp)); end if; Subp := Ultimate_Alias (Subp); if Present (Extra_Accessibility_Of_Result (Subp)) then Add_Extra_Actual_To_Call (Subprogram_Call => Exp, Extra_Formal => Extra_Accessibility_Of_Result (Subp), Extra_Actual => Dynamic_Accessibility_Level (PtrT)); end if; end; end if; -- Would be nice to comment the branches of this very long if ??? if Is_Tagged_Type (T) or else Needs_Finalization (T) then if Is_CPP_Constructor_Call (Exp) then -- Generate: -- Pnnn : constant ptr_T := new (T); -- Init (Pnnn.all,...); -- Allocate the object without an expression Node := Relocate_Node (N); Set_Expression (Node, New_Reference_To (Etype (Exp), Loc)); -- Avoid its expansion to avoid generating a call to the default -- C++ constructor. Set_Analyzed (Node); Temp := Make_Temporary (Loc, 'P', N); Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Constant_Present => True, Object_Definition => New_Reference_To (PtrT, Loc), Expression => Node); Insert_Action (N, Temp_Decl); Apply_Accessibility_Check (Temp); -- Locate the enclosing list and insert the C++ constructor call declare P : Node_Id; begin P := Parent (Node); while not Is_List_Member (P) loop P := Parent (P); end loop; Insert_List_After_And_Analyze (P, Build_Initialization_Call (Loc, Id_Ref => Make_Explicit_Dereference (Loc, Prefix => New_Reference_To (Temp, Loc)), Typ => Etype (Exp), Constructor_Ref => Exp)); end; Rewrite (N, New_Reference_To (Temp, Loc)); Analyze_And_Resolve (N, PtrT); return; end if; -- Ada 2005 (AI-318-02): If the initialization expression is a call -- to a build-in-place function, then access to the allocated object -- must be passed to the function. Currently we limit such functions -- to those with constrained limited result subtypes, but eventually -- we plan to expand the allowed forms of functions that are treated -- as build-in-place. if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function_Call (Exp) then Make_Build_In_Place_Call_In_Allocator (N, Exp); Apply_Accessibility_Check (N, Built_In_Place => True); return; end if; -- Actions inserted before: -- Temp : constant ptr_T := new T'(Expression); -- Temp._tag = T'tag; -- when not class-wide -- [Deep_]Adjust (Temp.all); -- We analyze by hand the new internal allocator to avoid any -- recursion and inappropriate call to Initialize -- We don't want to remove side effects when the expression must be -- built in place. In the case of a build-in-place function call, -- that could lead to a duplication of the call, which was already -- substituted for the allocator. if not Aggr_In_Place then Remove_Side_Effects (Exp); end if; Temp := Make_Temporary (Loc, 'P', N); -- For a class wide allocation generate the following code: -- type Equiv_Record is record ... end record; -- implicit subtype CW is <Class_Wide_Subytpe>; -- temp : PtrT := new CW'(CW!(expr)); if Is_Class_Wide_Type (T) then Expand_Subtype_From_Expr (Empty, T, Indic, Exp); -- Ada 2005 (AI-251): If the expression is a class-wide interface -- object we generate code to move up "this" to reference the -- base of the object before allocating the new object. -- Note that Exp'Address is recursively expanded into a call -- to Base_Address (Exp.Tag) if Is_Class_Wide_Type (Etype (Exp)) and then Is_Interface (Etype (Exp)) and then Tagged_Type_Expansion then Set_Expression (Expression (N), Unchecked_Convert_To (Entity (Indic), Make_Explicit_Dereference (Loc, Unchecked_Convert_To (RTE (RE_Tag_Ptr), Make_Attribute_Reference (Loc, Prefix => Exp, Attribute_Name => Name_Address))))); else Set_Expression (Expression (N), Unchecked_Convert_To (Entity (Indic), Exp)); end if; Analyze_And_Resolve (Expression (N), Entity (Indic)); end if; -- Processing for allocators returning non-interface types if not Is_Interface (Directly_Designated_Type (PtrT)) then if Aggr_In_Place then Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Object_Definition => New_Reference_To (PtrT, Loc), Expression => Make_Allocator (Loc, Expression => New_Reference_To (Etype (Exp), Loc))); -- Copy the Comes_From_Source flag for the allocator we just -- built, since logically this allocator is a replacement of -- the original allocator node. This is for proper handling of -- restriction No_Implicit_Heap_Allocations. Set_Comes_From_Source (Expression (Temp_Decl), Comes_From_Source (N)); Set_No_Initialization (Expression (Temp_Decl)); Insert_Action (N, Temp_Decl); Build_Allocate_Deallocate_Proc (Temp_Decl, True); Convert_Aggr_In_Allocator (N, Temp_Decl, Exp); -- Attach the object to the associated finalization master. -- This is done manually on .NET/JVM since those compilers do -- no support pools and can't benefit from internally generated -- Allocate / Deallocate procedures. if VM_Target /= No_VM and then Is_Controlled (DesigT) and then Present (Finalization_Master (PtrT)) then Insert_Action (N, Make_Attach_Call ( Obj_Ref => New_Reference_To (Temp, Loc), Ptr_Typ => PtrT)); end if; else Node := Relocate_Node (N); Set_Analyzed (Node); Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Constant_Present => True, Object_Definition => New_Reference_To (PtrT, Loc), Expression => Node); Insert_Action (N, Temp_Decl); Build_Allocate_Deallocate_Proc (Temp_Decl, True); -- Attach the object to the associated finalization master. -- This is done manually on .NET/JVM since those compilers do -- no support pools and can't benefit from internally generated -- Allocate / Deallocate procedures. if VM_Target /= No_VM and then Is_Controlled (DesigT) and then Present (Finalization_Master (PtrT)) then Insert_Action (N, Make_Attach_Call ( Obj_Ref => New_Reference_To (Temp, Loc), Ptr_Typ => PtrT)); end if; end if; -- Ada 2005 (AI-251): Handle allocators whose designated type is an -- interface type. In this case we use the type of the qualified -- expression to allocate the object. else declare Def_Id : constant Entity_Id := Make_Temporary (Loc, 'T'); New_Decl : Node_Id; begin New_Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Def_Id, Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => True, Null_Exclusion_Present => False, Constant_Present => False, Subtype_Indication => New_Reference_To (Etype (Exp), Loc))); Insert_Action (N, New_Decl); -- Inherit the allocation-related attributes from the original -- access type. Set_Finalization_Master (Def_Id, Finalization_Master (PtrT)); Set_Associated_Storage_Pool (Def_Id, Associated_Storage_Pool (PtrT)); -- Declare the object using the previous type declaration if Aggr_In_Place then Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Object_Definition => New_Reference_To (Def_Id, Loc), Expression => Make_Allocator (Loc, New_Reference_To (Etype (Exp), Loc))); -- Copy the Comes_From_Source flag for the allocator we just -- built, since logically this allocator is a replacement of -- the original allocator node. This is for proper handling -- of restriction No_Implicit_Heap_Allocations. Set_Comes_From_Source (Expression (Temp_Decl), Comes_From_Source (N)); Set_No_Initialization (Expression (Temp_Decl)); Insert_Action (N, Temp_Decl); Build_Allocate_Deallocate_Proc (Temp_Decl, True); Convert_Aggr_In_Allocator (N, Temp_Decl, Exp); else Node := Relocate_Node (N); Set_Analyzed (Node); Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Constant_Present => True, Object_Definition => New_Reference_To (Def_Id, Loc), Expression => Node); Insert_Action (N, Temp_Decl); Build_Allocate_Deallocate_Proc (Temp_Decl, True); end if; -- Generate an additional object containing the address of the -- returned object. The type of this second object declaration -- is the correct type required for the common processing that -- is still performed by this subprogram. The displacement of -- this pointer to reference the component associated with the -- interface type will be done at the end of common processing. New_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Make_Temporary (Loc, 'P'), Object_Definition => New_Reference_To (PtrT, Loc), Expression => Unchecked_Convert_To (PtrT, New_Reference_To (Temp, Loc))); Insert_Action (N, New_Decl); Temp_Decl := New_Decl; Temp := Defining_Identifier (New_Decl); end; end if; Apply_Accessibility_Check (Temp); -- Generate the tag assignment -- Suppress the tag assignment when VM_Target because VM tags are -- represented implicitly in objects. if not Tagged_Type_Expansion then null; -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide -- interface objects because in this case the tag does not change. elsif Is_Interface (Directly_Designated_Type (Etype (N))) then pragma Assert (Is_Class_Wide_Type (Directly_Designated_Type (Etype (N)))); null; elsif Is_Tagged_Type (T) and then not Is_Class_Wide_Type (T) then TagT := T; TagR := New_Reference_To (Temp, Loc); elsif Is_Private_Type (T) and then Is_Tagged_Type (Underlying_Type (T)) then TagT := Underlying_Type (T); TagR := Unchecked_Convert_To (Underlying_Type (T), Make_Explicit_Dereference (Loc, Prefix => New_Reference_To (Temp, Loc))); end if; if Present (TagT) then declare Full_T : constant Entity_Id := Underlying_Type (TagT); begin Tag_Assign := Make_Assignment_Statement (Loc, Name => Make_Selected_Component (Loc, Prefix => TagR, Selector_Name => New_Reference_To (First_Tag_Component (Full_T), Loc)), Expression => Unchecked_Convert_To (RTE (RE_Tag), New_Reference_To (Elists.Node (First_Elmt (Access_Disp_Table (Full_T))), Loc))); end; -- The previous assignment has to be done in any case Set_Assignment_OK (Name (Tag_Assign)); Insert_Action (N, Tag_Assign); end if; if Needs_Finalization (DesigT) and then Needs_Finalization (T) then -- Generate an Adjust call if the object will be moved. In Ada -- 2005, the object may be inherently limited, in which case -- there is no Adjust procedure, and the object is built in -- place. In Ada 95, the object can be limited but not -- inherently limited if this allocator came from a return -- statement (we're allocating the result on the secondary -- stack). In that case, the object will be moved, so we _do_ -- want to Adjust. if not Aggr_In_Place and then not Is_Immutably_Limited_Type (T) then Insert_Action (N, Make_Adjust_Call ( Obj_Ref => -- An unchecked conversion is needed in the classwide -- case because the designated type can be an ancestor -- of the subtype mark of the allocator. Unchecked_Convert_To (T, Make_Explicit_Dereference (Loc, Prefix => New_Reference_To (Temp, Loc))), Typ => T)); end if; -- Generate: -- Set_Finalize_Address (<PtrT>FM, <T>FD'Unrestricted_Access); -- Do not generate this call in the following cases: -- * .NET/JVM - these targets do not support address arithmetic -- and unchecked conversion, key elements of Finalize_Address. -- * Alfa mode - the call is useless and results in unwanted -- expansion. -- * CodePeer mode - TSS primitive Finalize_Address is not -- created in this mode. if VM_Target = No_VM and then not Alfa_Mode and then not CodePeer_Mode and then Present (Finalization_Master (PtrT)) and then Present (Temp_Decl) and then Nkind (Expression (Temp_Decl)) = N_Allocator then Insert_Action (N, Make_Set_Finalize_Address_Call (Loc => Loc, Typ => T, Ptr_Typ => PtrT)); end if; end if; Rewrite (N, New_Reference_To (Temp, Loc)); Analyze_And_Resolve (N, PtrT); -- Ada 2005 (AI-251): Displace the pointer to reference the record -- component containing the secondary dispatch table of the interface -- type. if Is_Interface (Directly_Designated_Type (PtrT)) then Displace_Allocator_Pointer (N); end if; elsif Aggr_In_Place then Temp := Make_Temporary (Loc, 'P', N); Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Object_Definition => New_Reference_To (PtrT, Loc), Expression => Make_Allocator (Loc, Expression => New_Reference_To (Etype (Exp), Loc))); -- Copy the Comes_From_Source flag for the allocator we just built, -- since logically this allocator is a replacement of the original -- allocator node. This is for proper handling of restriction -- No_Implicit_Heap_Allocations. Set_Comes_From_Source (Expression (Temp_Decl), Comes_From_Source (N)); Set_No_Initialization (Expression (Temp_Decl)); Insert_Action (N, Temp_Decl); Build_Allocate_Deallocate_Proc (Temp_Decl, True); Convert_Aggr_In_Allocator (N, Temp_Decl, Exp); -- Attach the object to the associated finalization master. Thisis -- done manually on .NET/JVM since those compilers do no support -- pools and cannot benefit from internally generated Allocate and -- Deallocate procedures. if VM_Target /= No_VM and then Is_Controlled (DesigT) and then Present (Finalization_Master (PtrT)) then Insert_Action (N, Make_Attach_Call (Obj_Ref => New_Reference_To (Temp, Loc), Ptr_Typ => PtrT)); end if; Rewrite (N, New_Reference_To (Temp, Loc)); Analyze_And_Resolve (N, PtrT); elsif Is_Access_Type (T) and then Can_Never_Be_Null (T) then Install_Null_Excluding_Check (Exp); elsif Is_Access_Type (DesigT) and then Nkind (Exp) = N_Allocator and then Nkind (Expression (Exp)) /= N_Qualified_Expression then -- Apply constraint to designated subtype indication Apply_Constraint_Check (Expression (Exp), Designated_Type (DesigT), No_Sliding => True); if Nkind (Expression (Exp)) = N_Raise_Constraint_Error then -- Propagate constraint_error to enclosing allocator Rewrite (Exp, New_Copy (Expression (Exp))); end if; else Build_Allocate_Deallocate_Proc (N, True); -- If we have: -- type A is access T1; -- X : A := new T2'(...); -- T1 and T2 can be different subtypes, and we might need to check -- both constraints. First check against the type of the qualified -- expression. Apply_Constraint_Check (Exp, T, No_Sliding => True); if Do_Range_Check (Exp) then Set_Do_Range_Check (Exp, False); Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed); end if; -- A check is also needed in cases where the designated subtype is -- constrained and differs from the subtype given in the qualified -- expression. Note that the check on the qualified expression does -- not allow sliding, but this check does (a relaxation from Ada 83). if Is_Constrained (DesigT) and then not Subtypes_Statically_Match (T, DesigT) then Apply_Constraint_Check (Exp, DesigT, No_Sliding => False); if Do_Range_Check (Exp) then Set_Do_Range_Check (Exp, False); Generate_Range_Check (Exp, DesigT, CE_Range_Check_Failed); end if; end if; -- For an access to unconstrained packed array, GIGI needs to see an -- expression with a constrained subtype in order to compute the -- proper size for the allocator. if Is_Array_Type (T) and then not Is_Constrained (T) and then Is_Packed (T) then declare ConstrT : constant Entity_Id := Make_Temporary (Loc, 'A'); Internal_Exp : constant Node_Id := Relocate_Node (Exp); begin Insert_Action (Exp, Make_Subtype_Declaration (Loc, Defining_Identifier => ConstrT, Subtype_Indication => Make_Subtype_From_Expr (Internal_Exp, T))); Freeze_Itype (ConstrT, Exp); Rewrite (Exp, OK_Convert_To (ConstrT, Internal_Exp)); end; end if; -- Ada 2005 (AI-318-02): If the initialization expression is a call -- to a build-in-place function, then access to the allocated object -- must be passed to the function. Currently we limit such functions -- to those with constrained limited result subtypes, but eventually -- we plan to expand the allowed forms of functions that are treated -- as build-in-place. if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function_Call (Exp) then Make_Build_In_Place_Call_In_Allocator (N, Exp); end if; end if; exception when RE_Not_Available => return; end Expand_Allocator_Expression; ----------------------------- -- Expand_Array_Comparison -- ----------------------------- -- Expansion is only required in the case of array types. For the unpacked -- case, an appropriate runtime routine is called. For packed cases, and -- also in some other cases where a runtime routine cannot be called, the -- form of the expansion is: -- [body for greater_nn; boolean_expression] -- The body is built by Make_Array_Comparison_Op, and the form of the -- Boolean expression depends on the operator involved. procedure Expand_Array_Comparison (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Op1 : Node_Id := Left_Opnd (N); Op2 : Node_Id := Right_Opnd (N); Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); Ctyp : constant Entity_Id := Component_Type (Typ1); Expr : Node_Id; Func_Body : Node_Id; Func_Name : Entity_Id; Comp : RE_Id; Byte_Addressable : constant Boolean := System_Storage_Unit = Byte'Size; -- True for byte addressable target function Length_Less_Than_4 (Opnd : Node_Id) return Boolean; -- Returns True if the length of the given operand is known to be less -- than 4. Returns False if this length is known to be four or greater -- or is not known at compile time. ------------------------ -- Length_Less_Than_4 -- ------------------------ function Length_Less_Than_4 (Opnd : Node_Id) return Boolean is Otyp : constant Entity_Id := Etype (Opnd); begin if Ekind (Otyp) = E_String_Literal_Subtype then return String_Literal_Length (Otyp) < 4; else declare Ityp : constant Entity_Id := Etype (First_Index (Otyp)); Lo : constant Node_Id := Type_Low_Bound (Ityp); Hi : constant Node_Id := Type_High_Bound (Ityp); Lov : Uint; Hiv : Uint; begin if Compile_Time_Known_Value (Lo) then Lov := Expr_Value (Lo); else return False; end if; if Compile_Time_Known_Value (Hi) then Hiv := Expr_Value (Hi); else return False; end if; return Hiv < Lov + 3; end; end if; end Length_Less_Than_4; -- Start of processing for Expand_Array_Comparison begin -- Deal first with unpacked case, where we can call a runtime routine -- except that we avoid this for targets for which are not addressable -- by bytes, and for the JVM/CIL, since they do not support direct -- addressing of array components. if not Is_Bit_Packed_Array (Typ1) and then Byte_Addressable and then VM_Target = No_VM then -- The call we generate is: -- Compare_Array_xn[_Unaligned] -- (left'address, right'address, left'length, right'length) <op> 0 -- x = U for unsigned, S for signed -- n = 8,16,32,64 for component size -- Add _Unaligned if length < 4 and component size is 8. -- <op> is the standard comparison operator if Component_Size (Typ1) = 8 then if Length_Less_Than_4 (Op1) or else Length_Less_Than_4 (Op2) then if Is_Unsigned_Type (Ctyp) then Comp := RE_Compare_Array_U8_Unaligned; else Comp := RE_Compare_Array_S8_Unaligned; end if; else if Is_Unsigned_Type (Ctyp) then Comp := RE_Compare_Array_U8; else Comp := RE_Compare_Array_S8; end if; end if; elsif Component_Size (Typ1) = 16 then if Is_Unsigned_Type (Ctyp) then Comp := RE_Compare_Array_U16; else Comp := RE_Compare_Array_S16; end if; elsif Component_Size (Typ1) = 32 then if Is_Unsigned_Type (Ctyp) then Comp := RE_Compare_Array_U32; else Comp := RE_Compare_Array_S32; end if; else pragma Assert (Component_Size (Typ1) = 64); if Is_Unsigned_Type (Ctyp) then Comp := RE_Compare_Array_U64; else Comp := RE_Compare_Array_S64; end if; end if; Remove_Side_Effects (Op1, Name_Req => True); Remove_Side_Effects (Op2, Name_Req => True); Rewrite (Op1, Make_Function_Call (Sloc (Op1), Name => New_Occurrence_Of (RTE (Comp), Loc), Parameter_Associations => New_List ( Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Op1), Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Op2), Attribute_Name => Name_Address), Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Op1), Attribute_Name => Name_Length), Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Op2), Attribute_Name => Name_Length)))); Rewrite (Op2, Make_Integer_Literal (Sloc (Op2), Intval => Uint_0)); Analyze_And_Resolve (Op1, Standard_Integer); Analyze_And_Resolve (Op2, Standard_Integer); return; end if; -- Cases where we cannot make runtime call -- For (a <= b) we convert to not (a > b) if Chars (N) = Name_Op_Le then Rewrite (N, Make_Op_Not (Loc, Right_Opnd => Make_Op_Gt (Loc, Left_Opnd => Op1, Right_Opnd => Op2))); Analyze_And_Resolve (N, Standard_Boolean); return; -- For < the Boolean expression is -- greater__nn (op2, op1) elsif Chars (N) = Name_Op_Lt then Func_Body := Make_Array_Comparison_Op (Typ1, N); -- Switch operands Op1 := Right_Opnd (N); Op2 := Left_Opnd (N); -- For (a >= b) we convert to not (a < b) elsif Chars (N) = Name_Op_Ge then Rewrite (N, Make_Op_Not (Loc, Right_Opnd => Make_Op_Lt (Loc, Left_Opnd => Op1, Right_Opnd => Op2))); Analyze_And_Resolve (N, Standard_Boolean); return; -- For > the Boolean expression is -- greater__nn (op1, op2) else pragma Assert (Chars (N) = Name_Op_Gt); Func_Body := Make_Array_Comparison_Op (Typ1, N); end if; Func_Name := Defining_Unit_Name (Specification (Func_Body)); Expr := Make_Function_Call (Loc, Name => New_Reference_To (Func_Name, Loc), Parameter_Associations => New_List (Op1, Op2)); Insert_Action (N, Func_Body); Rewrite (N, Expr); Analyze_And_Resolve (N, Standard_Boolean); exception when RE_Not_Available => return; end Expand_Array_Comparison; --------------------------- -- Expand_Array_Equality -- --------------------------- -- Expand an equality function for multi-dimensional arrays. Here is an -- example of such a function for Nb_Dimension = 2 -- function Enn (A : atyp; B : btyp) return boolean is -- begin -- if (A'length (1) = 0 or else A'length (2) = 0) -- and then -- (B'length (1) = 0 or else B'length (2) = 0) -- then -- return True; -- RM 4.5.2(22) -- end if; -- if A'length (1) /= B'length (1) -- or else -- A'length (2) /= B'length (2) -- then -- return False; -- RM 4.5.2(23) -- end if; -- declare -- A1 : Index_T1 := A'first (1); -- B1 : Index_T1 := B'first (1); -- begin -- loop -- declare -- A2 : Index_T2 := A'first (2); -- B2 : Index_T2 := B'first (2); -- begin -- loop -- if A (A1, A2) /= B (B1, B2) then -- return False; -- end if; -- exit when A2 = A'last (2); -- A2 := Index_T2'succ (A2); -- B2 := Index_T2'succ (B2); -- end loop; -- end; -- exit when A1 = A'last (1); -- A1 := Index_T1'succ (A1); -- B1 := Index_T1'succ (B1); -- end loop; -- end; -- return true; -- end Enn; -- Note on the formal types used (atyp and btyp). If either of the arrays -- is of a private type, we use the underlying type, and do an unchecked -- conversion of the actual. If either of the arrays has a bound depending -- on a discriminant, then we use the base type since otherwise we have an -- escaped discriminant in the function. -- If both arrays are constrained and have the same bounds, we can generate -- a loop with an explicit iteration scheme using a 'Range attribute over -- the first array. function Expand_Array_Equality (Nod : Node_Id; Lhs : Node_Id; Rhs : Node_Id; Bodies : List_Id; Typ : Entity_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Nod); Decls : constant List_Id := New_List; Index_List1 : constant List_Id := New_List; Index_List2 : constant List_Id := New_List; Actuals : List_Id; Formals : List_Id; Func_Name : Entity_Id; Func_Body : Node_Id; A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA); B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB); Ltyp : Entity_Id; Rtyp : Entity_Id; -- The parameter types to be used for the formals function Arr_Attr (Arr : Entity_Id; Nam : Name_Id; Num : Int) return Node_Id; -- This builds the attribute reference Arr'Nam (Expr) function Component_Equality (Typ : Entity_Id) return Node_Id; -- Create one statement to compare corresponding components, designated -- by a full set of indexes. function Get_Arg_Type (N : Node_Id) return Entity_Id; -- Given one of the arguments, computes the appropriate type to be used -- for that argument in the corresponding function formal function Handle_One_Dimension (N : Int; Index : Node_Id) return Node_Id; -- This procedure returns the following code -- -- declare -- Bn : Index_T := B'First (N); -- begin -- loop -- xxx -- exit when An = A'Last (N); -- An := Index_T'Succ (An) -- Bn := Index_T'Succ (Bn) -- end loop; -- end; -- -- If both indexes are constrained and identical, the procedure -- returns a simpler loop: -- -- for An in A'Range (N) loop -- xxx -- end loop -- -- N is the dimension for which we are generating a loop. Index is the -- N'th index node, whose Etype is Index_Type_n in the above code. The -- xxx statement is either the loop or declare for the next dimension -- or if this is the last dimension the comparison of corresponding -- components of the arrays. -- -- The actual way the code works is to return the comparison of -- corresponding components for the N+1 call. That's neater! function Test_Empty_Arrays return Node_Id; -- This function constructs the test for both arrays being empty -- (A'length (1) = 0 or else A'length (2) = 0 or else ...) -- and then -- (B'length (1) = 0 or else B'length (2) = 0 or else ...) function Test_Lengths_Correspond return Node_Id; -- This function constructs the test for arrays having different lengths -- in at least one index position, in which case the resulting code is: -- A'length (1) /= B'length (1) -- or else -- A'length (2) /= B'length (2) -- or else -- ... -------------- -- Arr_Attr -- -------------- function Arr_Attr (Arr : Entity_Id; Nam : Name_Id; Num : Int) return Node_Id is begin return Make_Attribute_Reference (Loc, Attribute_Name => Nam, Prefix => New_Reference_To (Arr, Loc), Expressions => New_List (Make_Integer_Literal (Loc, Num))); end Arr_Attr; ------------------------ -- Component_Equality -- ------------------------ function Component_Equality (Typ : Entity_Id) return Node_Id is Test : Node_Id; L, R : Node_Id; begin -- if a(i1...) /= b(j1...) then return false; end if; L := Make_Indexed_Component (Loc, Prefix => Make_Identifier (Loc, Chars (A)), Expressions => Index_List1); R := Make_Indexed_Component (Loc, Prefix => Make_Identifier (Loc, Chars (B)), Expressions => Index_List2); Test := Expand_Composite_Equality (Nod, Component_Type (Typ), L, R, Decls); -- If some (sub)component is an unchecked_union, the whole operation -- will raise program error. if Nkind (Test) = N_Raise_Program_Error then -- This node is going to be inserted at a location where a -- statement is expected: clear its Etype so analysis will set -- it to the expected Standard_Void_Type. Set_Etype (Test, Empty); return Test; else return Make_Implicit_If_Statement (Nod, Condition => Make_Op_Not (Loc, Right_Opnd => Test), Then_Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => New_Occurrence_Of (Standard_False, Loc)))); end if; end Component_Equality; ------------------ -- Get_Arg_Type -- ------------------ function Get_Arg_Type (N : Node_Id) return Entity_Id is T : Entity_Id; X : Node_Id; begin T := Etype (N); if No (T) then return Typ; else T := Underlying_Type (T); X := First_Index (T); while Present (X) loop if Denotes_Discriminant (Type_Low_Bound (Etype (X))) or else Denotes_Discriminant (Type_High_Bound (Etype (X))) then T := Base_Type (T); exit; end if; Next_Index (X); end loop; return T; end if; end Get_Arg_Type; -------------------------- -- Handle_One_Dimension -- --------------------------- function Handle_One_Dimension (N : Int; Index : Node_Id) return Node_Id is Need_Separate_Indexes : constant Boolean := Ltyp /= Rtyp or else not Is_Constrained (Ltyp); -- If the index types are identical, and we are working with -- constrained types, then we can use the same index for both -- of the arrays. An : constant Entity_Id := Make_Temporary (Loc, 'A'); Bn : Entity_Id; Index_T : Entity_Id; Stm_List : List_Id; Loop_Stm : Node_Id; begin if N > Number_Dimensions (Ltyp) then return Component_Equality (Ltyp); end if; -- Case where we generate a loop Index_T := Base_Type (Etype (Index)); if Need_Separate_Indexes then Bn := Make_Temporary (Loc, 'B'); else Bn := An; end if; Append (New_Reference_To (An, Loc), Index_List1); Append (New_Reference_To (Bn, Loc), Index_List2); Stm_List := New_List ( Handle_One_Dimension (N + 1, Next_Index (Index))); if Need_Separate_Indexes then -- Generate guard for loop, followed by increments of indexes Append_To (Stm_List, Make_Exit_Statement (Loc, Condition => Make_Op_Eq (Loc, Left_Opnd => New_Reference_To (An, Loc), Right_Opnd => Arr_Attr (A, Name_Last, N)))); Append_To (Stm_List, Make_Assignment_Statement (Loc, Name => New_Reference_To (An, Loc), Expression => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Index_T, Loc), Attribute_Name => Name_Succ, Expressions => New_List (New_Reference_To (An, Loc))))); Append_To (Stm_List, Make_Assignment_Statement (Loc, Name => New_Reference_To (Bn, Loc), Expression => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Index_T, Loc), Attribute_Name => Name_Succ, Expressions => New_List (New_Reference_To (Bn, Loc))))); end if; -- If separate indexes, we need a declare block for An and Bn, and a -- loop without an iteration scheme. if Need_Separate_Indexes then Loop_Stm := Make_Implicit_Loop_Statement (Nod, Statements => Stm_List); return Make_Block_Statement (Loc, Declarations => New_List ( Make_Object_Declaration (Loc, Defining_Identifier => An, Object_Definition => New_Reference_To (Index_T, Loc), Expression => Arr_Attr (A, Name_First, N)), Make_Object_Declaration (Loc, Defining_Identifier => Bn, Object_Definition => New_Reference_To (Index_T, Loc), Expression => Arr_Attr (B, Name_First, N))), Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (Loop_Stm))); -- If no separate indexes, return loop statement with explicit -- iteration scheme on its own else Loop_Stm := Make_Implicit_Loop_Statement (Nod, Statements => Stm_List, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => An, Discrete_Subtype_Definition => Arr_Attr (A, Name_Range, N)))); return Loop_Stm; end if; end Handle_One_Dimension; ----------------------- -- Test_Empty_Arrays -- ----------------------- function Test_Empty_Arrays return Node_Id is Alist : Node_Id; Blist : Node_Id; Atest : Node_Id; Btest : Node_Id; begin Alist := Empty; Blist := Empty; for J in 1 .. Number_Dimensions (Ltyp) loop Atest := Make_Op_Eq (Loc, Left_Opnd => Arr_Attr (A, Name_Length, J), Right_Opnd => Make_Integer_Literal (Loc, 0)); Btest := Make_Op_Eq (Loc, Left_Opnd => Arr_Attr (B, Name_Length, J), Right_Opnd => Make_Integer_Literal (Loc, 0)); if No (Alist) then Alist := Atest; Blist := Btest; else Alist := Make_Or_Else (Loc, Left_Opnd => Relocate_Node (Alist), Right_Opnd => Atest); Blist := Make_Or_Else (Loc, Left_Opnd => Relocate_Node (Blist), Right_Opnd => Btest); end if; end loop; return Make_And_Then (Loc, Left_Opnd => Alist, Right_Opnd => Blist); end Test_Empty_Arrays; ----------------------------- -- Test_Lengths_Correspond -- ----------------------------- function Test_Lengths_Correspond return Node_Id is Result : Node_Id; Rtest : Node_Id; begin Result := Empty; for J in 1 .. Number_Dimensions (Ltyp) loop Rtest := Make_Op_Ne (Loc, Left_Opnd => Arr_Attr (A, Name_Length, J), Right_Opnd => Arr_Attr (B, Name_Length, J)); if No (Result) then Result := Rtest; else Result := Make_Or_Else (Loc, Left_Opnd => Relocate_Node (Result), Right_Opnd => Rtest); end if; end loop; return Result; end Test_Lengths_Correspond; -- Start of processing for Expand_Array_Equality begin Ltyp := Get_Arg_Type (Lhs); Rtyp := Get_Arg_Type (Rhs); -- For now, if the argument types are not the same, go to the base type, -- since the code assumes that the formals have the same type. This is -- fixable in future ??? if Ltyp /= Rtyp then Ltyp := Base_Type (Ltyp); Rtyp := Base_Type (Rtyp); pragma Assert (Ltyp = Rtyp); end if; -- Build list of formals for function Formals := New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => A, Parameter_Type => New_Reference_To (Ltyp, Loc)), Make_Parameter_Specification (Loc, Defining_Identifier => B, Parameter_Type => New_Reference_To (Rtyp, Loc))); Func_Name := Make_Temporary (Loc, 'E'); -- Build statement sequence for function Func_Body := Make_Subprogram_Body (Loc, Specification => Make_Function_Specification (Loc, Defining_Unit_Name => Func_Name, Parameter_Specifications => Formals, Result_Definition => New_Reference_To (Standard_Boolean, Loc)), Declarations => Decls, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Make_Implicit_If_Statement (Nod, Condition => Test_Empty_Arrays, Then_Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => New_Occurrence_Of (Standard_True, Loc)))), Make_Implicit_If_Statement (Nod, Condition => Test_Lengths_Correspond, Then_Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => New_Occurrence_Of (Standard_False, Loc)))), Handle_One_Dimension (1, First_Index (Ltyp)), Make_Simple_Return_Statement (Loc, Expression => New_Occurrence_Of (Standard_True, Loc))))); Set_Has_Completion (Func_Name, True); Set_Is_Inlined (Func_Name); -- If the array type is distinct from the type of the arguments, it -- is the full view of a private type. Apply an unchecked conversion -- to insure that analysis of the call succeeds. declare L, R : Node_Id; begin L := Lhs; R := Rhs; if No (Etype (Lhs)) or else Base_Type (Etype (Lhs)) /= Base_Type (Ltyp) then L := OK_Convert_To (Ltyp, Lhs); end if; if No (Etype (Rhs)) or else Base_Type (Etype (Rhs)) /= Base_Type (Rtyp) then R := OK_Convert_To (Rtyp, Rhs); end if; Actuals := New_List (L, R); end; Append_To (Bodies, Func_Body); return Make_Function_Call (Loc, Name => New_Reference_To (Func_Name, Loc), Parameter_Associations => Actuals); end Expand_Array_Equality; ----------------------------- -- Expand_Boolean_Operator -- ----------------------------- -- Note that we first get the actual subtypes of the operands, since we -- always want to deal with types that have bounds. procedure Expand_Boolean_Operator (N : Node_Id) is Typ : constant Entity_Id := Etype (N); begin -- Special case of bit packed array where both operands are known to be -- properly aligned. In this case we use an efficient run time routine -- to carry out the operation (see System.Bit_Ops). if Is_Bit_Packed_Array (Typ) and then not Is_Possibly_Unaligned_Object (Left_Opnd (N)) and then not Is_Possibly_Unaligned_Object (Right_Opnd (N)) then Expand_Packed_Boolean_Operator (N); return; end if; -- For the normal non-packed case, the general expansion is to build -- function for carrying out the comparison (use Make_Boolean_Array_Op) -- and then inserting it into the tree. The original operator node is -- then rewritten as a call to this function. We also use this in the -- packed case if either operand is a possibly unaligned object. declare Loc : constant Source_Ptr := Sloc (N); L : constant Node_Id := Relocate_Node (Left_Opnd (N)); R : constant Node_Id := Relocate_Node (Right_Opnd (N)); Func_Body : Node_Id; Func_Name : Entity_Id; begin Convert_To_Actual_Subtype (L); Convert_To_Actual_Subtype (R); Ensure_Defined (Etype (L), N); Ensure_Defined (Etype (R), N); Apply_Length_Check (R, Etype (L)); if Nkind (N) = N_Op_Xor then Silly_Boolean_Array_Xor_Test (N, Etype (L)); end if; if Nkind (Parent (N)) = N_Assignment_Statement and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R) then Build_Boolean_Array_Proc_Call (Parent (N), L, R); elsif Nkind (Parent (N)) = N_Op_Not and then Nkind (N) = N_Op_And and then Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R) then return; else Func_Body := Make_Boolean_Array_Op (Etype (L), N); Func_Name := Defining_Unit_Name (Specification (Func_Body)); Insert_Action (N, Func_Body); -- Now rewrite the expression with a call Rewrite (N, Make_Function_Call (Loc, Name => New_Reference_To (Func_Name, Loc), Parameter_Associations => New_List ( L, Make_Type_Conversion (Loc, New_Reference_To (Etype (L), Loc), R)))); Analyze_And_Resolve (N, Typ); end if; end; end Expand_Boolean_Operator; ------------------------------- -- Expand_Composite_Equality -- ------------------------------- -- This function is only called for comparing internal fields of composite -- types when these fields are themselves composites. This is a special -- case because it is not possible to respect normal Ada visibility rules. function Expand_Composite_Equality (Nod : Node_Id; Typ : Entity_Id; Lhs : Node_Id; Rhs : Node_Id; Bodies : List_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Nod); Full_Type : Entity_Id; Prim : Elmt_Id; Eq_Op : Entity_Id; function Find_Primitive_Eq return Node_Id; -- AI05-0123: Locate primitive equality for type if it exists, and -- build the corresponding call. If operation is abstract, replace -- call with an explicit raise. Return Empty if there is no primitive. ----------------------- -- Find_Primitive_Eq -- ----------------------- function Find_Primitive_Eq return Node_Id is Prim_E : Elmt_Id; Prim : Node_Id; begin Prim_E := First_Elmt (Collect_Primitive_Operations (Typ)); while Present (Prim_E) loop Prim := Node (Prim_E); -- Locate primitive equality with the right signature if Chars (Prim) = Name_Op_Eq and then Etype (First_Formal (Prim)) = Etype (Next_Formal (First_Formal (Prim))) and then Etype (Prim) = Standard_Boolean then if Is_Abstract_Subprogram (Prim) then return Make_Raise_Program_Error (Loc, Reason => PE_Explicit_Raise); else return Make_Function_Call (Loc, Name => New_Reference_To (Prim, Loc), Parameter_Associations => New_List (Lhs, Rhs)); end if; end if; Next_Elmt (Prim_E); end loop; -- If not found, predefined operation will be used return Empty; end Find_Primitive_Eq; -- Start of processing for Expand_Composite_Equality begin if Is_Private_Type (Typ) then Full_Type := Underlying_Type (Typ); else Full_Type := Typ; end if; -- Defense against malformed private types with no completion the error -- will be diagnosed later by check_completion if No (Full_Type) then return New_Reference_To (Standard_False, Loc); end if; Full_Type := Base_Type (Full_Type); if Is_Array_Type (Full_Type) then -- If the operand is an elementary type other than a floating-point -- type, then we can simply use the built-in block bitwise equality, -- since the predefined equality operators always apply and bitwise -- equality is fine for all these cases. if Is_Elementary_Type (Component_Type (Full_Type)) and then not Is_Floating_Point_Type (Component_Type (Full_Type)) then return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs); -- For composite component types, and floating-point types, use the -- expansion. This deals with tagged component types (where we use -- the applicable equality routine) and floating-point, (where we -- need to worry about negative zeroes), and also the case of any -- composite type recursively containing such fields. else return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Full_Type); end if; elsif Is_Tagged_Type (Full_Type) then -- Call the primitive operation "=" of this type if Is_Class_Wide_Type (Full_Type) then Full_Type := Root_Type (Full_Type); end if; -- If this is derived from an untagged private type completed with a -- tagged type, it does not have a full view, so we use the primitive -- operations of the private type. This check should no longer be -- necessary when these types receive their full views ??? if Is_Private_Type (Typ) and then not Is_Tagged_Type (Typ) and then not Is_Controlled (Typ) and then Is_Derived_Type (Typ) and then No (Full_View (Typ)) then Prim := First_Elmt (Collect_Primitive_Operations (Typ)); else Prim := First_Elmt (Primitive_Operations (Full_Type)); end if; loop Eq_Op := Node (Prim); exit when Chars (Eq_Op) = Name_Op_Eq and then Etype (First_Formal (Eq_Op)) = Etype (Next_Formal (First_Formal (Eq_Op))) and then Base_Type (Etype (Eq_Op)) = Standard_Boolean; Next_Elmt (Prim); pragma Assert (Present (Prim)); end loop; Eq_Op := Node (Prim); return Make_Function_Call (Loc, Name => New_Reference_To (Eq_Op, Loc), Parameter_Associations => New_List (Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Lhs), Unchecked_Convert_To (Etype (First_Formal (Eq_Op)), Rhs))); elsif Is_Record_Type (Full_Type) then Eq_Op := TSS (Full_Type, TSS_Composite_Equality); if Present (Eq_Op) then if Etype (First_Formal (Eq_Op)) /= Full_Type then -- Inherited equality from parent type. Convert the actuals to -- match signature of operation. declare T : constant Entity_Id := Etype (First_Formal (Eq_Op)); begin return Make_Function_Call (Loc, Name => New_Reference_To (Eq_Op, Loc), Parameter_Associations => New_List ( OK_Convert_To (T, Lhs), OK_Convert_To (T, Rhs))); end; else -- Comparison between Unchecked_Union components if Is_Unchecked_Union (Full_Type) then declare Lhs_Type : Node_Id := Full_Type; Rhs_Type : Node_Id := Full_Type; Lhs_Discr_Val : Node_Id; Rhs_Discr_Val : Node_Id; begin -- Lhs subtype if Nkind (Lhs) = N_Selected_Component then Lhs_Type := Etype (Entity (Selector_Name (Lhs))); end if; -- Rhs subtype if Nkind (Rhs) = N_Selected_Component then Rhs_Type := Etype (Entity (Selector_Name (Rhs))); end if; -- Lhs of the composite equality if Is_Constrained (Lhs_Type) then -- Since the enclosing record type can never be an -- Unchecked_Union (this code is executed for records -- that do not have variants), we may reference its -- discriminant(s). if Nkind (Lhs) = N_Selected_Component and then Has_Per_Object_Constraint ( Entity (Selector_Name (Lhs))) then Lhs_Discr_Val := Make_Selected_Component (Loc, Prefix => Prefix (Lhs), Selector_Name => New_Copy (Get_Discriminant_Value (First_Discriminant (Lhs_Type), Lhs_Type, Stored_Constraint (Lhs_Type)))); else Lhs_Discr_Val := New_Copy (Get_Discriminant_Value (First_Discriminant (Lhs_Type), Lhs_Type, Stored_Constraint (Lhs_Type))); end if; else -- It is not possible to infer the discriminant since -- the subtype is not constrained. return Make_Raise_Program_Error (Loc, Reason => PE_Unchecked_Union_Restriction); end if; -- Rhs of the composite equality if Is_Constrained (Rhs_Type) then if Nkind (Rhs) = N_Selected_Component and then Has_Per_Object_Constraint (Entity (Selector_Name (Rhs))) then Rhs_Discr_Val := Make_Selected_Component (Loc, Prefix => Prefix (Rhs), Selector_Name => New_Copy (Get_Discriminant_Value (First_Discriminant (Rhs_Type), Rhs_Type, Stored_Constraint (Rhs_Type)))); else Rhs_Discr_Val := New_Copy (Get_Discriminant_Value (First_Discriminant (Rhs_Type), Rhs_Type, Stored_Constraint (Rhs_Type))); end if; else return Make_Raise_Program_Error (Loc, Reason => PE_Unchecked_Union_Restriction); end if; -- Call the TSS equality function with the inferred -- discriminant values. return Make_Function_Call (Loc, Name => New_Reference_To (Eq_Op, Loc), Parameter_Associations => New_List ( Lhs, Rhs, Lhs_Discr_Val, Rhs_Discr_Val)); end; else return Make_Function_Call (Loc, Name => New_Reference_To (Eq_Op, Loc), Parameter_Associations => New_List (Lhs, Rhs)); end if; end if; elsif Ada_Version >= Ada_2012 then -- if no TSS has been created for the type, check whether there is -- a primitive equality declared for it. declare Ada_2012_Op : constant Node_Id := Find_Primitive_Eq; begin if Present (Ada_2012_Op) then return Ada_2012_Op; else -- Use predefined equality if no user-defined primitive exists return Make_Op_Eq (Loc, Lhs, Rhs); end if; end; else return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies); end if; else -- If not array or record type, it is predefined equality. return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs); end if; end Expand_Composite_Equality; ------------------------ -- Expand_Concatenate -- ------------------------ procedure Expand_Concatenate (Cnode : Node_Id; Opnds : List_Id) is Loc : constant Source_Ptr := Sloc (Cnode); Atyp : constant Entity_Id := Base_Type (Etype (Cnode)); -- Result type of concatenation Ctyp : constant Entity_Id := Base_Type (Component_Type (Etype (Cnode))); -- Component type. Elements of this component type can appear as one -- of the operands of concatenation as well as arrays. Istyp : constant Entity_Id := Etype (First_Index (Atyp)); -- Index subtype Ityp : constant Entity_Id := Base_Type (Istyp); -- Index type. This is the base type of the index subtype, and is used -- for all computed bounds (which may be out of range of Istyp in the -- case of null ranges). Artyp : Entity_Id; -- This is the type we use to do arithmetic to compute the bounds and -- lengths of operands. The choice of this type is a little subtle and -- is discussed in a separate section at the start of the body code. Concatenation_Error : exception; -- Raised if concatenation is sure to raise a CE Result_May_Be_Null : Boolean := True; -- Reset to False if at least one operand is encountered which is known -- at compile time to be non-null. Used for handling the special case -- of setting the high bound to the last operand high bound for a null -- result, thus ensuring a proper high bound in the super-flat case. N : constant Nat := List_Length (Opnds); -- Number of concatenation operands including possibly null operands NN : Nat := 0; -- Number of operands excluding any known to be null, except that the -- last operand is always retained, in case it provides the bounds for -- a null result. Opnd : Node_Id; -- Current operand being processed in the loop through operands. After -- this loop is complete, always contains the last operand (which is not -- the same as Operands (NN), since null operands are skipped). -- Arrays describing the operands, only the first NN entries of each -- array are set (NN < N when we exclude known null operands). Is_Fixed_Length : array (1 .. N) of Boolean; -- True if length of corresponding operand known at compile time Operands : array (1 .. N) of Node_Id; -- Set to the corresponding entry in the Opnds list (but note that null -- operands are excluded, so not all entries in the list are stored). Fixed_Length : array (1 .. N) of Uint; -- Set to length of operand. Entries in this array are set only if the -- corresponding entry in Is_Fixed_Length is True. Opnd_Low_Bound : array (1 .. N) of Node_Id; -- Set to lower bound of operand. Either an integer literal in the case -- where the bound is known at compile time, else actual lower bound. -- The operand low bound is of type Ityp. Var_Length : array (1 .. N) of Entity_Id; -- Set to an entity of type Natural that contains the length of an -- operand whose length is not known at compile time. Entries in this -- array are set only if the corresponding entry in Is_Fixed_Length -- is False. The entity is of type Artyp. Aggr_Length : array (0 .. N) of Node_Id; -- The J'th entry in an expression node that represents the total length -- of operands 1 through J. It is either an integer literal node, or a -- reference to a constant entity with the right value, so it is fine -- to just do a Copy_Node to get an appropriate copy. The extra zero'th -- entry always is set to zero. The length is of type Artyp. Low_Bound : Node_Id; -- A tree node representing the low bound of the result (of type Ityp). -- This is either an integer literal node, or an identifier reference to -- a constant entity initialized to the appropriate value. Last_Opnd_Low_Bound : Node_Id; -- A tree node representing the low bound of the last operand. This -- need only be set if the result could be null. It is used for the -- special case of setting the right low bound for a null result. -- This is of type Ityp. Last_Opnd_High_Bound : Node_Id; -- A tree node representing the high bound of the last operand. This -- need only be set if the result could be null. It is used for the -- special case of setting the right high bound for a null result. -- This is of type Ityp. High_Bound : Node_Id; -- A tree node representing the high bound of the result (of type Ityp) Result : Node_Id; -- Result of the concatenation (of type Ityp) Actions : constant List_Id := New_List; -- Collect actions to be inserted Known_Non_Null_Operand_Seen : Boolean; -- Set True during generation of the assignments of operands into -- result once an operand known to be non-null has been seen. function Make_Artyp_Literal (Val : Nat) return Node_Id; -- This function makes an N_Integer_Literal node that is returned in -- analyzed form with the type set to Artyp. Importantly this literal -- is not flagged as static, so that if we do computations with it that -- result in statically detected out of range conditions, we will not -- generate error messages but instead warning messages. function To_Artyp (X : Node_Id) return Node_Id; -- Given a node of type Ityp, returns the corresponding value of type -- Artyp. For non-enumeration types, this is a plain integer conversion. -- For enum types, the Pos of the value is returned. function To_Ityp (X : Node_Id) return Node_Id; -- The inverse function (uses Val in the case of enumeration types) ------------------------ -- Make_Artyp_Literal -- ------------------------ function Make_Artyp_Literal (Val : Nat) return Node_Id is Result : constant Node_Id := Make_Integer_Literal (Loc, Val); begin Set_Etype (Result, Artyp); Set_Analyzed (Result, True); Set_Is_Static_Expression (Result, False); return Result; end Make_Artyp_Literal; -------------- -- To_Artyp -- -------------- function To_Artyp (X : Node_Id) return Node_Id is begin if Ityp = Base_Type (Artyp) then return X; elsif Is_Enumeration_Type (Ityp) then return Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Ityp, Loc), Attribute_Name => Name_Pos, Expressions => New_List (X)); else return Convert_To (Artyp, X); end if; end To_Artyp; ------------- -- To_Ityp -- ------------- function To_Ityp (X : Node_Id) return Node_Id is begin if Is_Enumeration_Type (Ityp) then return Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Ityp, Loc), Attribute_Name => Name_Val, Expressions => New_List (X)); -- Case where we will do a type conversion else if Ityp = Base_Type (Artyp) then return X; else return Convert_To (Ityp, X); end if; end if; end To_Ityp; -- Local Declarations Opnd_Typ : Entity_Id; Ent : Entity_Id; Len : Uint; J : Nat; Clen : Node_Id; Set : Boolean; -- Start of processing for Expand_Concatenate begin -- Choose an appropriate computational type -- We will be doing calculations of lengths and bounds in this routine -- and computing one from the other in some cases, e.g. getting the high -- bound by adding the length-1 to the low bound. -- We can't just use the index type, or even its base type for this -- purpose for two reasons. First it might be an enumeration type which -- is not suitable for computations of any kind, and second it may -- simply not have enough range. For example if the index type is -- -128..+127 then lengths can be up to 256, which is out of range of -- the type. -- For enumeration types, we can simply use Standard_Integer, this is -- sufficient since the actual number of enumeration literals cannot -- possibly exceed the range of integer (remember we will be doing the -- arithmetic with POS values, not representation values). if Is_Enumeration_Type (Ityp) then Artyp := Standard_Integer; -- If index type is Positive, we use the standard unsigned type, to give -- more room on the top of the range, obviating the need for an overflow -- check when creating the upper bound. This is needed to avoid junk -- overflow checks in the common case of String types. -- ??? Disabled for now -- elsif Istyp = Standard_Positive then -- Artyp := Standard_Unsigned; -- For modular types, we use a 32-bit modular type for types whose size -- is in the range 1-31 bits. For 32-bit unsigned types, we use the -- identity type, and for larger unsigned types we use 64-bits. elsif Is_Modular_Integer_Type (Ityp) then if RM_Size (Ityp) < RM_Size (Standard_Unsigned) then Artyp := Standard_Unsigned; elsif RM_Size (Ityp) = RM_Size (Standard_Unsigned) then Artyp := Ityp; else Artyp := RTE (RE_Long_Long_Unsigned); end if; -- Similar treatment for signed types else if RM_Size (Ityp) < RM_Size (Standard_Integer) then Artyp := Standard_Integer; elsif RM_Size (Ityp) = RM_Size (Standard_Integer) then Artyp := Ityp; else Artyp := Standard_Long_Long_Integer; end if; end if; -- Supply dummy entry at start of length array Aggr_Length (0) := Make_Artyp_Literal (0); -- Go through operands setting up the above arrays J := 1; while J <= N loop Opnd := Remove_Head (Opnds); Opnd_Typ := Etype (Opnd); -- The parent got messed up when we put the operands in a list, -- so now put back the proper parent for the saved operand, that -- is to say the concatenation node, to make sure that each operand -- is seen as a subexpression, e.g. if actions must be inserted. Set_Parent (Opnd, Cnode); -- Set will be True when we have setup one entry in the array Set := False; -- Singleton element (or character literal) case if Base_Type (Opnd_Typ) = Ctyp then NN := NN + 1; Operands (NN) := Opnd; Is_Fixed_Length (NN) := True; Fixed_Length (NN) := Uint_1; Result_May_Be_Null := False; -- Set low bound of operand (no need to set Last_Opnd_High_Bound -- since we know that the result cannot be null). Opnd_Low_Bound (NN) := Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Istyp, Loc), Attribute_Name => Name_First); Set := True; -- String literal case (can only occur for strings of course) elsif Nkind (Opnd) = N_String_Literal then Len := String_Literal_Length (Opnd_Typ); if Len /= 0 then Result_May_Be_Null := False; end if; -- Capture last operand low and high bound if result could be null if J = N and then Result_May_Be_Null then Last_Opnd_Low_Bound := New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)); Last_Opnd_High_Bound := Make_Op_Subtract (Loc, Left_Opnd => New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)), Right_Opnd => Make_Integer_Literal (Loc, 1)); end if; -- Skip null string literal if J < N and then Len = 0 then goto Continue; end if; NN := NN + 1; Operands (NN) := Opnd; Is_Fixed_Length (NN) := True; -- Set length and bounds Fixed_Length (NN) := Len; Opnd_Low_Bound (NN) := New_Copy_Tree (String_Literal_Low_Bound (Opnd_Typ)); Set := True; -- All other cases else -- Check constrained case with known bounds if Is_Constrained (Opnd_Typ) then declare Index : constant Node_Id := First_Index (Opnd_Typ); Indx_Typ : constant Entity_Id := Etype (Index); Lo : constant Node_Id := Type_Low_Bound (Indx_Typ); Hi : constant Node_Id := Type_High_Bound (Indx_Typ); begin -- Fixed length constrained array type with known at compile -- time bounds is last case of fixed length operand. if Compile_Time_Known_Value (Lo) and then Compile_Time_Known_Value (Hi) then declare Loval : constant Uint := Expr_Value (Lo); Hival : constant Uint := Expr_Value (Hi); Len : constant Uint := UI_Max (Hival - Loval + 1, Uint_0); begin if Len > 0 then Result_May_Be_Null := False; end if; -- Capture last operand bounds if result could be null if J = N and then Result_May_Be_Null then Last_Opnd_Low_Bound := Convert_To (Ityp, Make_Integer_Literal (Loc, Expr_Value (Lo))); Last_Opnd_High_Bound := Convert_To (Ityp, Make_Integer_Literal (Loc, Expr_Value (Hi))); end if; -- Exclude null length case unless last operand if J < N and then Len = 0 then goto Continue; end if; NN := NN + 1; Operands (NN) := Opnd; Is_Fixed_Length (NN) := True; Fixed_Length (NN) := Len; Opnd_Low_Bound (NN) := To_Ityp (Make_Integer_Literal (Loc, Expr_Value (Lo))); Set := True; end; end if; end; end if; -- All cases where the length is not known at compile time, or the -- special case of an operand which is known to be null but has a -- lower bound other than 1 or is other than a string type. if not Set then NN := NN + 1; -- Capture operand bounds Opnd_Low_Bound (NN) := Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr (Opnd, Name_Req => True), Attribute_Name => Name_First); -- Capture last operand bounds if result could be null if J = N and Result_May_Be_Null then Last_Opnd_Low_Bound := Convert_To (Ityp, Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr (Opnd, Name_Req => True), Attribute_Name => Name_First)); Last_Opnd_High_Bound := Convert_To (Ityp, Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr (Opnd, Name_Req => True), Attribute_Name => Name_Last)); end if; -- Capture length of operand in entity Operands (NN) := Opnd; Is_Fixed_Length (NN) := False; Var_Length (NN) := Make_Temporary (Loc, 'L'); Append_To (Actions, Make_Object_Declaration (Loc, Defining_Identifier => Var_Length (NN), Constant_Present => True, Object_Definition => New_Occurrence_Of (Artyp, Loc), Expression => Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr (Opnd, Name_Req => True), Attribute_Name => Name_Length))); end if; end if; -- Set next entry in aggregate length array -- For first entry, make either integer literal for fixed length -- or a reference to the saved length for variable length. if NN = 1 then if Is_Fixed_Length (1) then Aggr_Length (1) := Make_Integer_Literal (Loc, Fixed_Length (1)); else Aggr_Length (1) := New_Reference_To (Var_Length (1), Loc); end if; -- If entry is fixed length and only fixed lengths so far, make -- appropriate new integer literal adding new length. elsif Is_Fixed_Length (NN) and then Nkind (Aggr_Length (NN - 1)) = N_Integer_Literal then Aggr_Length (NN) := Make_Integer_Literal (Loc, Intval => Fixed_Length (NN) + Intval (Aggr_Length (NN - 1))); -- All other cases, construct an addition node for the length and -- create an entity initialized to this length. else Ent := Make_Temporary (Loc, 'L'); if Is_Fixed_Length (NN) then Clen := Make_Integer_Literal (Loc, Fixed_Length (NN)); else Clen := New_Reference_To (Var_Length (NN), Loc); end if; Append_To (Actions, Make_Object_Declaration (Loc, Defining_Identifier => Ent, Constant_Present => True, Object_Definition => New_Occurrence_Of (Artyp, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Copy (Aggr_Length (NN - 1)), Right_Opnd => Clen))); Aggr_Length (NN) := Make_Identifier (Loc, Chars => Chars (Ent)); end if; <<Continue>> J := J + 1; end loop; -- If we have only skipped null operands, return the last operand if NN = 0 then Result := Opnd; goto Done; end if; -- If we have only one non-null operand, return it and we are done. -- There is one case in which this cannot be done, and that is when -- the sole operand is of the element type, in which case it must be -- converted to an array, and the easiest way of doing that is to go -- through the normal general circuit. if NN = 1 and then Base_Type (Etype (Operands (1))) /= Ctyp then Result := Operands (1); goto Done; end if; -- Cases where we have a real concatenation -- Next step is to find the low bound for the result array that we -- will allocate. The rules for this are in (RM 4.5.6(5-7)). -- If the ultimate ancestor of the index subtype is a constrained array -- definition, then the lower bound is that of the index subtype as -- specified by (RM 4.5.3(6)). -- The right test here is to go to the root type, and then the ultimate -- ancestor is the first subtype of this root type. if Is_Constrained (First_Subtype (Root_Type (Atyp))) then Low_Bound := Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (First_Subtype (Root_Type (Atyp)), Loc), Attribute_Name => Name_First); -- If the first operand in the list has known length we know that -- the lower bound of the result is the lower bound of this operand. elsif Is_Fixed_Length (1) then Low_Bound := Opnd_Low_Bound (1); -- OK, we don't know the lower bound, we have to build a horrible -- expression actions node of the form -- if Cond1'Length /= 0 then -- Opnd1 low bound -- else -- if Opnd2'Length /= 0 then -- Opnd2 low bound -- else -- ... -- The nesting ends either when we hit an operand whose length is known -- at compile time, or on reaching the last operand, whose low bound we -- take unconditionally whether or not it is null. It's easiest to do -- this with a recursive procedure: else declare function Get_Known_Bound (J : Nat) return Node_Id; -- Returns the lower bound determined by operands J .. NN --------------------- -- Get_Known_Bound -- --------------------- function Get_Known_Bound (J : Nat) return Node_Id is begin if Is_Fixed_Length (J) or else J = NN then return New_Copy (Opnd_Low_Bound (J)); else return Make_Conditional_Expression (Loc, Expressions => New_List ( Make_Op_Ne (Loc, Left_Opnd => New_Reference_To (Var_Length (J), Loc), Right_Opnd => Make_Integer_Literal (Loc, 0)), New_Copy (Opnd_Low_Bound (J)), Get_Known_Bound (J + 1))); end if; end Get_Known_Bound; begin Ent := Make_Temporary (Loc, 'L'); Append_To (Actions, Make_Object_Declaration (Loc, Defining_Identifier => Ent, Constant_Present => True, Object_Definition => New_Occurrence_Of (Ityp, Loc), Expression => Get_Known_Bound (1))); Low_Bound := New_Reference_To (Ent, Loc); end; end if; -- Now we can safely compute the upper bound, normally -- Low_Bound + Length - 1. High_Bound := To_Ityp ( Make_Op_Add (Loc, Left_Opnd => To_Artyp (New_Copy (Low_Bound)), Right_Opnd => Make_Op_Subtract (Loc, Left_Opnd => New_Copy (Aggr_Length (NN)), Right_Opnd => Make_Artyp_Literal (1)))); -- Note that calculation of the high bound may cause overflow in some -- very weird cases, so in the general case we need an overflow check on -- the high bound. We can avoid this for the common case of string types -- and other types whose index is Positive, since we chose a wider range -- for the arithmetic type. if Istyp /= Standard_Positive then Activate_Overflow_Check (High_Bound); end if; -- Handle the exceptional case where the result is null, in which case -- case the bounds come from the last operand (so that we get the proper -- bounds if the last operand is super-flat). if Result_May_Be_Null then Low_Bound := Make_Conditional_Expression (Loc, Expressions => New_List ( Make_Op_Eq (Loc, Left_Opnd => New_Copy (Aggr_Length (NN)), Right_Opnd => Make_Artyp_Literal (0)), Last_Opnd_Low_Bound, Low_Bound)); High_Bound := Make_Conditional_Expression (Loc, Expressions => New_List ( Make_Op_Eq (Loc, Left_Opnd => New_Copy (Aggr_Length (NN)), Right_Opnd => Make_Artyp_Literal (0)), Last_Opnd_High_Bound, High_Bound)); end if; -- Here is where we insert the saved up actions Insert_Actions (Cnode, Actions, Suppress => All_Checks); -- Now we construct an array object with appropriate bounds. We mark -- the target as internal to prevent useless initialization when -- Initialize_Scalars is enabled. Also since this is the actual result -- entity, we make sure we have debug information for the result. Ent := Make_Temporary (Loc, 'S'); Set_Is_Internal (Ent); Set_Needs_Debug_Info (Ent); -- If the bound is statically known to be out of range, we do not want -- to abort, we want a warning and a runtime constraint error. Note that -- we have arranged that the result will not be treated as a static -- constant, so we won't get an illegality during this insertion. Insert_Action (Cnode, Make_Object_Declaration (Loc, Defining_Identifier => Ent, Object_Definition => Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Atyp, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List ( Make_Range (Loc, Low_Bound => Low_Bound, High_Bound => High_Bound))))), Suppress => All_Checks); -- If the result of the concatenation appears as the initializing -- expression of an object declaration, we can just rename the -- result, rather than copying it. Set_OK_To_Rename (Ent); -- Catch the static out of range case now if Raises_Constraint_Error (High_Bound) then raise Concatenation_Error; end if; -- Now we will generate the assignments to do the actual concatenation -- There is one case in which we will not do this, namely when all the -- following conditions are met: -- The result type is Standard.String -- There are nine or fewer retained (non-null) operands -- The optimization level is -O0 -- The corresponding System.Concat_n.Str_Concat_n routine is -- available in the run time. -- The debug flag gnatd.c is not set -- If all these conditions are met then we generate a call to the -- relevant concatenation routine. The purpose of this is to avoid -- undesirable code bloat at -O0. if Atyp = Standard_String and then NN in 2 .. 9 and then (Opt.Optimization_Level = 0 or else Debug_Flag_Dot_CC) and then not Debug_Flag_Dot_C then declare RR : constant array (Nat range 2 .. 9) of RE_Id := (RE_Str_Concat_2, RE_Str_Concat_3, RE_Str_Concat_4, RE_Str_Concat_5, RE_Str_Concat_6, RE_Str_Concat_7, RE_Str_Concat_8, RE_Str_Concat_9); begin if RTE_Available (RR (NN)) then declare Opnds : constant List_Id := New_List (New_Occurrence_Of (Ent, Loc)); begin for J in 1 .. NN loop if Is_List_Member (Operands (J)) then Remove (Operands (J)); end if; if Base_Type (Etype (Operands (J))) = Ctyp then Append_To (Opnds, Make_Aggregate (Loc, Component_Associations => New_List ( Make_Component_Association (Loc, Choices => New_List ( Make_Integer_Literal (Loc, 1)), Expression => Operands (J))))); else Append_To (Opnds, Operands (J)); end if; end loop; Insert_Action (Cnode, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RR (NN)), Loc), Parameter_Associations => Opnds)); Result := New_Reference_To (Ent, Loc); goto Done; end; end if; end; end if; -- Not special case so generate the assignments Known_Non_Null_Operand_Seen := False; for J in 1 .. NN loop declare Lo : constant Node_Id := Make_Op_Add (Loc, Left_Opnd => To_Artyp (New_Copy (Low_Bound)), Right_Opnd => Aggr_Length (J - 1)); Hi : constant Node_Id := Make_Op_Add (Loc, Left_Opnd => To_Artyp (New_Copy (Low_Bound)), Right_Opnd => Make_Op_Subtract (Loc, Left_Opnd => Aggr_Length (J), Right_Opnd => Make_Artyp_Literal (1))); begin -- Singleton case, simple assignment if Base_Type (Etype (Operands (J))) = Ctyp then Known_Non_Null_Operand_Seen := True; Insert_Action (Cnode, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Ent, Loc), Expressions => New_List (To_Ityp (Lo))), Expression => Operands (J)), Suppress => All_Checks); -- Array case, slice assignment, skipped when argument is fixed -- length and known to be null. elsif (not Is_Fixed_Length (J)) or else (Fixed_Length (J) > 0) then declare Assign : Node_Id := Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Ent, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => To_Ityp (Lo), High_Bound => To_Ityp (Hi))), Expression => Operands (J)); begin if Is_Fixed_Length (J) then Known_Non_Null_Operand_Seen := True; elsif not Known_Non_Null_Operand_Seen then -- Here if operand length is not statically known and no -- operand known to be non-null has been processed yet. -- If operand length is 0, we do not need to perform the -- assignment, and we must avoid the evaluation of the -- high bound of the slice, since it may underflow if the -- low bound is Ityp'First. Assign := Make_Implicit_If_Statement (Cnode, Condition => Make_Op_Ne (Loc, Left_Opnd => New_Occurrence_Of (Var_Length (J), Loc), Right_Opnd => Make_Integer_Literal (Loc, 0)), Then_Statements => New_List (Assign)); end if; Insert_Action (Cnode, Assign, Suppress => All_Checks); end; end if; end; end loop; -- Finally we build the result, which is a reference to the array object Result := New_Reference_To (Ent, Loc); <<Done>> Rewrite (Cnode, Result); Analyze_And_Resolve (Cnode, Atyp); exception when Concatenation_Error => -- Kill warning generated for the declaration of the static out of -- range high bound, and instead generate a Constraint_Error with -- an appropriate specific message. Kill_Dead_Code (Declaration_Node (Entity (High_Bound))); Apply_Compile_Time_Constraint_Error (N => Cnode, Msg => "concatenation result upper bound out of range?", Reason => CE_Range_Check_Failed); -- Set_Etype (Cnode, Atyp); end Expand_Concatenate; ------------------------ -- Expand_N_Allocator -- ------------------------ procedure Expand_N_Allocator (N : Node_Id) is PtrT : constant Entity_Id := Etype (N); Dtyp : constant Entity_Id := Available_View (Designated_Type (PtrT)); Etyp : constant Entity_Id := Etype (Expression (N)); Loc : constant Source_Ptr := Sloc (N); Desig : Entity_Id; Nod : Node_Id; Pool : Entity_Id; Temp : Entity_Id; procedure Rewrite_Coextension (N : Node_Id); -- Static coextensions have the same lifetime as the entity they -- constrain. Such occurrences can be rewritten as aliased objects -- and their unrestricted access used instead of the coextension. function Size_In_Storage_Elements (E : Entity_Id) return Node_Id; -- Given a constrained array type E, returns a node representing the -- code to compute the size in storage elements for the given type. -- This is done without using the attribute (which malfunctions for -- large sizes ???) ------------------------- -- Rewrite_Coextension -- ------------------------- procedure Rewrite_Coextension (N : Node_Id) is Temp_Id : constant Node_Id := Make_Temporary (Loc, 'C'); Temp_Decl : Node_Id; Insert_Nod : Node_Id; begin -- Generate: -- Cnn : aliased Etyp; Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp_Id, Aliased_Present => True, Object_Definition => New_Occurrence_Of (Etyp, Loc)); if Nkind (Expression (N)) = N_Qualified_Expression then Set_Expression (Temp_Decl, Expression (Expression (N))); end if; -- Find the proper insertion node for the declaration Insert_Nod := Parent (N); while Present (Insert_Nod) loop exit when Nkind (Insert_Nod) in N_Statement_Other_Than_Procedure_Call or else Nkind (Insert_Nod) = N_Procedure_Call_Statement or else Nkind (Insert_Nod) in N_Declaration; Insert_Nod := Parent (Insert_Nod); end loop; Insert_Before (Insert_Nod, Temp_Decl); Analyze (Temp_Decl); Rewrite (N, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Temp_Id, Loc), Attribute_Name => Name_Unrestricted_Access)); Analyze_And_Resolve (N, PtrT); end Rewrite_Coextension; ------------------------------ -- Size_In_Storage_Elements -- ------------------------------ function Size_In_Storage_Elements (E : Entity_Id) return Node_Id is begin -- Logically this just returns E'Max_Size_In_Storage_Elements. -- However, the reason for the existence of this function is -- to construct a test for sizes too large, which means near the -- 32-bit limit on a 32-bit machine, and precisely the trouble -- is that we get overflows when sizes are greater than 2**31. -- So what we end up doing for array types is to use the expression: -- number-of-elements * component_type'Max_Size_In_Storage_Elements -- which avoids this problem. All this is a bit bogus, but it does -- mean we catch common cases of trying to allocate arrays that -- are too large, and which in the absence of a check results in -- undetected chaos ??? declare Len : Node_Id; Res : Node_Id; begin for J in 1 .. Number_Dimensions (E) loop Len := Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (E, Loc), Attribute_Name => Name_Length, Expressions => New_List (Make_Integer_Literal (Loc, J))); if J = 1 then Res := Len; else Res := Make_Op_Multiply (Loc, Left_Opnd => Res, Right_Opnd => Len); end if; end loop; return Make_Op_Multiply (Loc, Left_Opnd => Len, Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Component_Type (E), Loc), Attribute_Name => Name_Max_Size_In_Storage_Elements)); end; end Size_In_Storage_Elements; -- Start of processing for Expand_N_Allocator begin -- RM E.2.3(22). We enforce that the expected type of an allocator -- shall not be a remote access-to-class-wide-limited-private type -- Why is this being done at expansion time, seems clearly wrong ??? Validate_Remote_Access_To_Class_Wide_Type (N); -- Processing for anonymous access-to-controlled types. These access -- types receive a special finalization master which appears in the -- declarations of the enclosing semantic unit. This expansion is done -- now to ensure that any additional types generated by this routine -- or Expand_Allocator_Expression inherit the proper type attributes. if Ekind (PtrT) = E_Anonymous_Access_Type and then Needs_Finalization (Dtyp) then -- Anonymous access-to-controlled types allocate on the global pool. -- Do not set this attribute on .NET/JVM since those targets do not -- support pools. if No (Associated_Storage_Pool (PtrT)) and then VM_Target = No_VM then Set_Associated_Storage_Pool (PtrT, Get_Global_Pool_For_Access_Type (PtrT)); end if; -- The finalization master must be inserted and analyzed as part of -- the current semantic unit. This form of expansion is not carried -- out in Alfa mode because it is useless. Note that the master is -- updated when analysis changes current units. if not Alfa_Mode then Set_Finalization_Master (PtrT, Current_Anonymous_Master); end if; end if; -- Set the storage pool and find the appropriate version of Allocate to -- call. Do not overwrite the storage pool if it is already set, which -- can happen for build-in-place function returns (see -- Exp_Ch4.Expand_N_Extended_Return_Statement). if No (Storage_Pool (N)) then Pool := Associated_Storage_Pool (Root_Type (PtrT)); if Present (Pool) then Set_Storage_Pool (N, Pool); if Is_RTE (Pool, RE_SS_Pool) then if VM_Target = No_VM then Set_Procedure_To_Call (N, RTE (RE_SS_Allocate)); end if; -- In the case of an allocator for a simple storage pool, locate -- and save a reference to the pool type's Allocate routine. elsif Present (Get_Rep_Pragma (Etype (Pool), Name_Simple_Storage_Pool_Type)) then declare Pool_Type : constant Entity_Id := Base_Type (Etype (Pool)); Alloc_Op : Entity_Id; begin Alloc_Op := Get_Name_Entity_Id (Name_Allocate); while Present (Alloc_Op) loop if Scope (Alloc_Op) = Scope (Pool_Type) and then Present (First_Formal (Alloc_Op)) and then Etype (First_Formal (Alloc_Op)) = Pool_Type then Set_Procedure_To_Call (N, Alloc_Op); exit; else Alloc_Op := Homonym (Alloc_Op); end if; end loop; end; elsif Is_Class_Wide_Type (Etype (Pool)) then Set_Procedure_To_Call (N, RTE (RE_Allocate_Any)); else Set_Procedure_To_Call (N, Find_Prim_Op (Etype (Pool), Name_Allocate)); end if; end if; end if; -- Under certain circumstances we can replace an allocator by an access -- to statically allocated storage. The conditions, as noted in AARM -- 3.10 (10c) are as follows: -- Size and initial value is known at compile time -- Access type is access-to-constant -- The allocator is not part of a constraint on a record component, -- because in that case the inserted actions are delayed until the -- record declaration is fully analyzed, which is too late for the -- analysis of the rewritten allocator. if Is_Access_Constant (PtrT) and then Nkind (Expression (N)) = N_Qualified_Expression and then Compile_Time_Known_Value (Expression (Expression (N))) and then Size_Known_At_Compile_Time (Etype (Expression (Expression (N)))) and then not Is_Record_Type (Current_Scope) then -- Here we can do the optimization. For the allocator -- new x'(y) -- We insert an object declaration -- Tnn : aliased x := y; -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is -- marked as requiring static allocation. Temp := Make_Temporary (Loc, 'T', Expression (Expression (N))); Desig := Subtype_Mark (Expression (N)); -- If context is constrained, use constrained subtype directly, -- so that the constant is not labelled as having a nominally -- unconstrained subtype. if Entity (Desig) = Base_Type (Dtyp) then Desig := New_Occurrence_Of (Dtyp, Loc); end if; Insert_Action (N, Make_Object_Declaration (Loc, Defining_Identifier => Temp, Aliased_Present => True, Constant_Present => Is_Access_Constant (PtrT), Object_Definition => Desig, Expression => Expression (Expression (N)))); Rewrite (N, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Temp, Loc), Attribute_Name => Name_Unrestricted_Access)); Analyze_And_Resolve (N, PtrT); -- We set the variable as statically allocated, since we don't want -- it going on the stack of the current procedure! Set_Is_Statically_Allocated (Temp); return; end if; -- Same if the allocator is an access discriminant for a local object: -- instead of an allocator we create a local value and constrain the -- enclosing object with the corresponding access attribute. if Is_Static_Coextension (N) then Rewrite_Coextension (N); return; end if; -- Check for size too large, we do this because the back end misses -- proper checks here and can generate rubbish allocation calls when -- we are near the limit. We only do this for the 32-bit address case -- since that is from a practical point of view where we see a problem. if System_Address_Size = 32 and then not Storage_Checks_Suppressed (PtrT) and then not Storage_Checks_Suppressed (Dtyp) and then not Storage_Checks_Suppressed (Etyp) then -- The check we want to generate should look like -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then -- raise Storage_Error; -- end if; -- where 3.5 gigabytes is a constant large enough to accommodate any -- reasonable request for. But we can't do it this way because at -- least at the moment we don't compute this attribute right, and -- can silently give wrong results when the result gets large. Since -- this is all about large results, that's bad, so instead we only -- apply the check for constrained arrays, and manually compute the -- value of the attribute ??? if Is_Array_Type (Etyp) and then Is_Constrained (Etyp) then Insert_Action (N, Make_Raise_Storage_Error (Loc, Condition => Make_Op_Gt (Loc, Left_Opnd => Size_In_Storage_Elements (Etyp), Right_Opnd => Make_Integer_Literal (Loc, Uint_7 * (Uint_2 ** 29))), Reason => SE_Object_Too_Large)); end if; end if; -- Handle case of qualified expression (other than optimization above) -- First apply constraint checks, because the bounds or discriminants -- in the aggregate might not match the subtype mark in the allocator. if Nkind (Expression (N)) = N_Qualified_Expression then Apply_Constraint_Check (Expression (Expression (N)), Etype (Expression (N))); Expand_Allocator_Expression (N); return; end if; -- If the allocator is for a type which requires initialization, and -- there is no initial value (i.e. operand is a subtype indication -- rather than a qualified expression), then we must generate a call to -- the initialization routine using an expressions action node: -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn] -- Here ptr_T is the pointer type for the allocator, and T is the -- subtype of the allocator. A special case arises if the designated -- type of the access type is a task or contains tasks. In this case -- the call to Init (Temp.all ...) is replaced by code that ensures -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block -- for details). In addition, if the type T is a task T, then the -- first argument to Init must be converted to the task record type. declare T : constant Entity_Id := Entity (Expression (N)); Args : List_Id; Decls : List_Id; Decl : Node_Id; Discr : Elmt_Id; Init : Entity_Id; Init_Arg1 : Node_Id; Temp_Decl : Node_Id; Temp_Type : Entity_Id; begin if No_Initialization (N) then -- Even though this might be a simple allocation, create a custom -- Allocate if the context requires it. Since .NET/JVM compilers -- do not support pools, this step is skipped. if VM_Target = No_VM and then Present (Finalization_Master (PtrT)) then Build_Allocate_Deallocate_Proc (N => N, Is_Allocate => True); end if; -- Case of no initialization procedure present elsif not Has_Non_Null_Base_Init_Proc (T) then -- Case of simple initialization required if Needs_Simple_Initialization (T) then Check_Restriction (No_Default_Initialization, N); Rewrite (Expression (N), Make_Qualified_Expression (Loc, Subtype_Mark => New_Occurrence_Of (T, Loc), Expression => Get_Simple_Init_Val (T, N))); Analyze_And_Resolve (Expression (Expression (N)), T); Analyze_And_Resolve (Expression (N), T); Set_Paren_Count (Expression (Expression (N)), 1); Expand_N_Allocator (N); -- No initialization required else null; end if; -- Case of initialization procedure present, must be called else Check_Restriction (No_Default_Initialization, N); if not Restriction_Active (No_Default_Initialization) then Init := Base_Init_Proc (T); Nod := N; Temp := Make_Temporary (Loc, 'P'); -- Construct argument list for the initialization routine call Init_Arg1 := Make_Explicit_Dereference (Loc, Prefix => New_Reference_To (Temp, Loc)); Set_Assignment_OK (Init_Arg1); Temp_Type := PtrT; -- The initialization procedure expects a specific type. if the -- context is access to class wide, indicate that the object -- being allocated has the right specific type. if Is_Class_Wide_Type (Dtyp) then Init_Arg1 := Unchecked_Convert_To (T, Init_Arg1); end if; -- If designated type is a concurrent type or if it is private -- type whose definition is a concurrent type, the first -- argument in the Init routine has to be unchecked conversion -- to the corresponding record type. If the designated type is -- a derived type, also convert the argument to its root type. if Is_Concurrent_Type (T) then Init_Arg1 := Unchecked_Convert_To ( Corresponding_Record_Type (T), Init_Arg1); elsif Is_Private_Type (T) and then Present (Full_View (T)) and then Is_Concurrent_Type (Full_View (T)) then Init_Arg1 := Unchecked_Convert_To (Corresponding_Record_Type (Full_View (T)), Init_Arg1); elsif Etype (First_Formal (Init)) /= Base_Type (T) then declare Ftyp : constant Entity_Id := Etype (First_Formal (Init)); begin Init_Arg1 := OK_Convert_To (Etype (Ftyp), Init_Arg1); Set_Etype (Init_Arg1, Ftyp); end; end if; Args := New_List (Init_Arg1); -- For the task case, pass the Master_Id of the access type as -- the value of the _Master parameter, and _Chain as the value -- of the _Chain parameter (_Chain will be defined as part of -- the generated code for the allocator). -- In Ada 2005, the context may be a function that returns an -- anonymous access type. In that case the Master_Id has been -- created when expanding the function declaration. if Has_Task (T) then if No (Master_Id (Base_Type (PtrT))) then -- The designated type was an incomplete type, and the -- access type did not get expanded. Salvage it now. if not Restriction_Active (No_Task_Hierarchy) then pragma Assert (Present (Parent (Base_Type (PtrT)))); Expand_N_Full_Type_Declaration (Parent (Base_Type (PtrT))); end if; end if; -- If the context of the allocator is a declaration or an -- assignment, we can generate a meaningful image for it, -- even though subsequent assignments might remove the -- connection between task and entity. We build this image -- when the left-hand side is a simple variable, a simple -- indexed assignment or a simple selected component. if Nkind (Parent (N)) = N_Assignment_Statement then declare Nam : constant Node_Id := Name (Parent (N)); begin if Is_Entity_Name (Nam) then Decls := Build_Task_Image_Decls (Loc, New_Occurrence_Of (Entity (Nam), Sloc (Nam)), T); elsif Nkind_In (Nam, N_Indexed_Component, N_Selected_Component) and then Is_Entity_Name (Prefix (Nam)) then Decls := Build_Task_Image_Decls (Loc, Nam, Etype (Prefix (Nam))); else Decls := Build_Task_Image_Decls (Loc, T, T); end if; end; elsif Nkind (Parent (N)) = N_Object_Declaration then Decls := Build_Task_Image_Decls (Loc, Defining_Identifier (Parent (N)), T); else Decls := Build_Task_Image_Decls (Loc, T, T); end if; if Restriction_Active (No_Task_Hierarchy) then Append_To (Args, New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc)); else Append_To (Args, New_Reference_To (Master_Id (Base_Type (Root_Type (PtrT))), Loc)); end if; Append_To (Args, Make_Identifier (Loc, Name_uChain)); Decl := Last (Decls); Append_To (Args, New_Occurrence_Of (Defining_Identifier (Decl), Loc)); -- Has_Task is false, Decls not used else Decls := No_List; end if; -- Add discriminants if discriminated type declare Dis : Boolean := False; Typ : Entity_Id; begin if Has_Discriminants (T) then Dis := True; Typ := T; elsif Is_Private_Type (T) and then Present (Full_View (T)) and then Has_Discriminants (Full_View (T)) then Dis := True; Typ := Full_View (T); end if; if Dis then -- If the allocated object will be constrained by the -- default values for discriminants, then build a subtype -- with those defaults, and change the allocated subtype -- to that. Note that this happens in fewer cases in Ada -- 2005 (AI-363). if not Is_Constrained (Typ) and then Present (Discriminant_Default_Value (First_Discriminant (Typ))) and then (Ada_Version < Ada_2005 or else not Effectively_Has_Constrained_Partial_View (Typ => Typ, Scop => Current_Scope)) then Typ := Build_Default_Subtype (Typ, N); Set_Expression (N, New_Reference_To (Typ, Loc)); end if; Discr := First_Elmt (Discriminant_Constraint (Typ)); while Present (Discr) loop Nod := Node (Discr); Append (New_Copy_Tree (Node (Discr)), Args); -- AI-416: when the discriminant constraint is an -- anonymous access type make sure an accessibility -- check is inserted if necessary (3.10.2(22.q/2)) if Ada_Version >= Ada_2005 and then Ekind (Etype (Nod)) = E_Anonymous_Access_Type then Apply_Accessibility_Check (Nod, Typ, Insert_Node => Nod); end if; Next_Elmt (Discr); end loop; end if; end; -- We set the allocator as analyzed so that when we analyze the -- expression actions node, we do not get an unwanted recursive -- expansion of the allocator expression. Set_Analyzed (N, True); Nod := Relocate_Node (N); -- Here is the transformation: -- input: new Ctrl_Typ -- output: Temp : constant Ctrl_Typ_Ptr := new Ctrl_Typ; -- Ctrl_TypIP (Temp.all, ...); -- [Deep_]Initialize (Temp.all); -- Here Ctrl_Typ_Ptr is the pointer type for the allocator, and -- is the subtype of the allocator. Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Constant_Present => True, Object_Definition => New_Reference_To (Temp_Type, Loc), Expression => Nod); Set_Assignment_OK (Temp_Decl); Insert_Action (N, Temp_Decl, Suppress => All_Checks); Build_Allocate_Deallocate_Proc (Temp_Decl, True); -- If the designated type is a task type or contains tasks, -- create block to activate created tasks, and insert -- declaration for Task_Image variable ahead of call. if Has_Task (T) then declare L : constant List_Id := New_List; Blk : Node_Id; begin Build_Task_Allocate_Block (L, Nod, Args); Blk := Last (L); Insert_List_Before (First (Declarations (Blk)), Decls); Insert_Actions (N, L); end; else Insert_Action (N, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Init, Loc), Parameter_Associations => Args)); end if; if Needs_Finalization (T) then -- Generate: -- [Deep_]Initialize (Init_Arg1); Insert_Action (N, Make_Init_Call (Obj_Ref => New_Copy_Tree (Init_Arg1), Typ => T)); if Present (Finalization_Master (PtrT)) then -- Special processing for .NET/JVM, the allocated object -- is attached to the finalization master. Generate: -- Attach (<PtrT>FM, Root_Controlled_Ptr (Init_Arg1)); -- Types derived from [Limited_]Controlled are the only -- ones considered since they have fields Prev and Next. if VM_Target /= No_VM then if Is_Controlled (T) then Insert_Action (N, Make_Attach_Call (Obj_Ref => New_Copy_Tree (Init_Arg1), Ptr_Typ => PtrT)); end if; -- Default case, generate: -- Set_Finalize_Address -- (<PtrT>FM, <T>FD'Unrestricted_Access); -- Do not generate this call in the following cases: -- -- * Alfa mode - the call is useless and results in -- unwanted expansion. -- -- * CodePeer mode - TSS primitive Finalize_Address is -- not created in this mode. elsif not Alfa_Mode and then not CodePeer_Mode then Insert_Action (N, Make_Set_Finalize_Address_Call (Loc => Loc, Typ => T, Ptr_Typ => PtrT)); end if; end if; end if; Rewrite (N, New_Reference_To (Temp, Loc)); Analyze_And_Resolve (N, PtrT); end if; end if; end; -- Ada 2005 (AI-251): If the allocator is for a class-wide interface -- object that has been rewritten as a reference, we displace "this" -- to reference properly its secondary dispatch table. if Nkind (N) = N_Identifier and then Is_Interface (Dtyp) then Displace_Allocator_Pointer (N); end if; exception when RE_Not_Available => return; end Expand_N_Allocator; ----------------------- -- Expand_N_And_Then -- ----------------------- procedure Expand_N_And_Then (N : Node_Id) renames Expand_Short_Circuit_Operator; ------------------------------ -- Expand_N_Case_Expression -- ------------------------------ procedure Expand_N_Case_Expression (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Cstmt : Node_Id; Tnn : Entity_Id; Pnn : Entity_Id; Actions : List_Id; Ttyp : Entity_Id; Alt : Node_Id; Fexp : Node_Id; begin -- We expand -- case X is when A => AX, when B => BX ... -- to -- do -- Tnn : typ; -- case X is -- when A => -- Tnn := AX; -- when B => -- Tnn := BX; -- ... -- end case; -- in Tnn end; -- However, this expansion is wrong for limited types, and also -- wrong for unconstrained types (since the bounds may not be the -- same in all branches). Furthermore it involves an extra copy -- for large objects. So we take care of this by using the following -- modified expansion for non-scalar types: -- do -- type Pnn is access all typ; -- Tnn : Pnn; -- case X is -- when A => -- T := AX'Unrestricted_Access; -- when B => -- T := BX'Unrestricted_Access; -- ... -- end case; -- in Tnn.all end; Cstmt := Make_Case_Statement (Loc, Expression => Expression (N), Alternatives => New_List); Actions := New_List; -- Scalar case if Is_Scalar_Type (Typ) then Ttyp := Typ; else Pnn := Make_Temporary (Loc, 'P'); Append_To (Actions, Make_Full_Type_Declaration (Loc, Defining_Identifier => Pnn, Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => True, Subtype_Indication => New_Reference_To (Typ, Loc)))); Ttyp := Pnn; end if; Tnn := Make_Temporary (Loc, 'T'); Append_To (Actions, Make_Object_Declaration (Loc, Defining_Identifier => Tnn, Object_Definition => New_Occurrence_Of (Ttyp, Loc))); -- Now process the alternatives Alt := First (Alternatives (N)); while Present (Alt) loop declare Aexp : Node_Id := Expression (Alt); Aloc : constant Source_Ptr := Sloc (Aexp); Stats : List_Id; begin -- As described above, take Unrestricted_Access for case of non- -- scalar types, to avoid big copies, and special cases. if not Is_Scalar_Type (Typ) then Aexp := Make_Attribute_Reference (Aloc, Prefix => Relocate_Node (Aexp), Attribute_Name => Name_Unrestricted_Access); end if; Stats := New_List ( Make_Assignment_Statement (Aloc, Name => New_Occurrence_Of (Tnn, Loc), Expression => Aexp)); -- Propagate declarations inserted in the node by Insert_Actions -- (for example, temporaries generated to remove side effects). -- These actions must remain attached to the alternative, given -- that they are generated by the corresponding expression. if Present (Sinfo.Actions (Alt)) then Prepend_List (Sinfo.Actions (Alt), Stats); end if; Append_To (Alternatives (Cstmt), Make_Case_Statement_Alternative (Sloc (Alt), Discrete_Choices => Discrete_Choices (Alt), Statements => Stats)); end; Next (Alt); end loop; Append_To (Actions, Cstmt); -- Construct and return final expression with actions if Is_Scalar_Type (Typ) then Fexp := New_Occurrence_Of (Tnn, Loc); else Fexp := Make_Explicit_Dereference (Loc, Prefix => New_Occurrence_Of (Tnn, Loc)); end if; Rewrite (N, Make_Expression_With_Actions (Loc, Expression => Fexp, Actions => Actions)); Analyze_And_Resolve (N, Typ); end Expand_N_Case_Expression; ------------------------------------- -- Expand_N_Conditional_Expression -- ------------------------------------- -- Deal with limited types and expression actions procedure Expand_N_Conditional_Expression (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Cond : constant Node_Id := First (Expressions (N)); Thenx : constant Node_Id := Next (Cond); Elsex : constant Node_Id := Next (Thenx); Typ : constant Entity_Id := Etype (N); Cnn : Entity_Id; Decl : Node_Id; New_If : Node_Id; New_N : Node_Id; P_Decl : Node_Id; Expr : Node_Id; Actions : List_Id; begin -- Fold at compile time if condition known. We have already folded -- static conditional expressions, but it is possible to fold any -- case in which the condition is known at compile time, even though -- the result is non-static. -- Note that we don't do the fold of such cases in Sem_Elab because -- it can cause infinite loops with the expander adding a conditional -- expression, and Sem_Elab circuitry removing it repeatedly. if Compile_Time_Known_Value (Cond) then if Is_True (Expr_Value (Cond)) then Expr := Thenx; Actions := Then_Actions (N); else Expr := Elsex; Actions := Else_Actions (N); end if; Remove (Expr); if Present (Actions) then -- If we are not allowed to use Expression_With_Actions, just skip -- the optimization, it is not critical for correctness. if not Use_Expression_With_Actions then goto Skip_Optimization; end if; Rewrite (N, Make_Expression_With_Actions (Loc, Expression => Relocate_Node (Expr), Actions => Actions)); Analyze_And_Resolve (N, Typ); else Rewrite (N, Relocate_Node (Expr)); end if; -- Note that the result is never static (legitimate cases of static -- conditional expressions were folded in Sem_Eval). Set_Is_Static_Expression (N, False); return; end if; <<Skip_Optimization>> -- If the type is limited or unconstrained, we expand as follows to -- avoid any possibility of improper copies. -- Note: it may be possible to avoid this special processing if the -- back end uses its own mechanisms for handling by-reference types ??? -- type Ptr is access all Typ; -- Cnn : Ptr; -- if cond then -- <<then actions>> -- Cnn := then-expr'Unrestricted_Access; -- else -- <<else actions>> -- Cnn := else-expr'Unrestricted_Access; -- end if; -- and replace the conditional expression by a reference to Cnn.all. -- This special case can be skipped if the back end handles limited -- types properly and ensures that no incorrect copies are made. if Is_By_Reference_Type (Typ) and then not Back_End_Handles_Limited_Types then Cnn := Make_Temporary (Loc, 'C', N); P_Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Make_Temporary (Loc, 'A'), Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => True, Subtype_Indication => New_Reference_To (Typ, Loc))); Insert_Action (N, P_Decl); Decl := Make_Object_Declaration (Loc, Defining_Identifier => Cnn, Object_Definition => New_Occurrence_Of (Defining_Identifier (P_Decl), Loc)); New_If := Make_Implicit_If_Statement (N, Condition => Relocate_Node (Cond), Then_Statements => New_List ( Make_Assignment_Statement (Sloc (Thenx), Name => New_Occurrence_Of (Cnn, Sloc (Thenx)), Expression => Make_Attribute_Reference (Loc, Attribute_Name => Name_Unrestricted_Access, Prefix => Relocate_Node (Thenx)))), Else_Statements => New_List ( Make_Assignment_Statement (Sloc (Elsex), Name => New_Occurrence_Of (Cnn, Sloc (Elsex)), Expression => Make_Attribute_Reference (Loc, Attribute_Name => Name_Unrestricted_Access, Prefix => Relocate_Node (Elsex))))); New_N := Make_Explicit_Dereference (Loc, Prefix => New_Occurrence_Of (Cnn, Loc)); -- For other types, we only need to expand if there are other actions -- associated with either branch. elsif Present (Then_Actions (N)) or else Present (Else_Actions (N)) then -- We have two approaches to handling this. If we are allowed to use -- N_Expression_With_Actions, then we can just wrap the actions into -- the appropriate expression. if Use_Expression_With_Actions then if Present (Then_Actions (N)) then Rewrite (Thenx, Make_Expression_With_Actions (Sloc (Thenx), Actions => Then_Actions (N), Expression => Relocate_Node (Thenx))); Set_Then_Actions (N, No_List); Analyze_And_Resolve (Thenx, Typ); end if; if Present (Else_Actions (N)) then Rewrite (Elsex, Make_Expression_With_Actions (Sloc (Elsex), Actions => Else_Actions (N), Expression => Relocate_Node (Elsex))); Set_Else_Actions (N, No_List); Analyze_And_Resolve (Elsex, Typ); end if; return; -- if we can't use N_Expression_With_Actions nodes, then we insert -- the following sequence of actions (using Insert_Actions): -- Cnn : typ; -- if cond then -- <<then actions>> -- Cnn := then-expr; -- else -- <<else actions>> -- Cnn := else-expr -- end if; -- and replace the conditional expression by a reference to Cnn else Cnn := Make_Temporary (Loc, 'C', N); Decl := Make_Object_Declaration (Loc, Defining_Identifier => Cnn, Object_Definition => New_Occurrence_Of (Typ, Loc)); New_If := Make_Implicit_If_Statement (N, Condition => Relocate_Node (Cond), Then_Statements => New_List ( Make_Assignment_Statement (Sloc (Thenx), Name => New_Occurrence_Of (Cnn, Sloc (Thenx)), Expression => Relocate_Node (Thenx))), Else_Statements => New_List ( Make_Assignment_Statement (Sloc (Elsex), Name => New_Occurrence_Of (Cnn, Sloc (Elsex)), Expression => Relocate_Node (Elsex)))); Set_Assignment_OK (Name (First (Then_Statements (New_If)))); Set_Assignment_OK (Name (First (Else_Statements (New_If)))); New_N := New_Occurrence_Of (Cnn, Loc); end if; -- If no actions then no expansion needed, gigi will handle it using -- the same approach as a C conditional expression. else return; end if; -- Fall through here for either the limited expansion, or the case of -- inserting actions for non-limited types. In both these cases, we must -- move the SLOC of the parent If statement to the newly created one and -- change it to the SLOC of the expression which, after expansion, will -- correspond to what is being evaluated. if Present (Parent (N)) and then Nkind (Parent (N)) = N_If_Statement then Set_Sloc (New_If, Sloc (Parent (N))); Set_Sloc (Parent (N), Loc); end if; -- Make sure Then_Actions and Else_Actions are appropriately moved -- to the new if statement. if Present (Then_Actions (N)) then Insert_List_Before (First (Then_Statements (New_If)), Then_Actions (N)); end if; if Present (Else_Actions (N)) then Insert_List_Before (First (Else_Statements (New_If)), Else_Actions (N)); end if; Insert_Action (N, Decl); Insert_Action (N, New_If); Rewrite (N, New_N); Analyze_And_Resolve (N, Typ); end Expand_N_Conditional_Expression; ----------------------------------- -- Expand_N_Explicit_Dereference -- ----------------------------------- procedure Expand_N_Explicit_Dereference (N : Node_Id) is begin -- Insert explicit dereference call for the checked storage pool case Insert_Dereference_Action (Prefix (N)); -- If the type is an Atomic type for which Atomic_Sync is enabled, then -- we set the atomic sync flag. if Is_Atomic (Etype (N)) and then not Atomic_Synchronization_Disabled (Etype (N)) then Activate_Atomic_Synchronization (N); end if; end Expand_N_Explicit_Dereference; -------------------------------------- -- Expand_N_Expression_With_Actions -- -------------------------------------- procedure Expand_N_Expression_With_Actions (N : Node_Id) is procedure Process_Transient_Object (Decl : Node_Id); -- Given the declaration of a controlled transient declared inside the -- Actions list of an Expression_With_Actions, generate all necessary -- types and hooks in order to properly finalize the transient. This -- mechanism works in conjunction with Build_Finalizer. ------------------------------ -- Process_Transient_Object -- ------------------------------ procedure Process_Transient_Object (Decl : Node_Id) is function Find_Insertion_Node return Node_Id; -- Complex conditions in if statements may be converted into nested -- EWAs. In this case, any generated code must be inserted before the -- if statement to ensure proper visibility of the hook objects. This -- routine returns the top most short circuit operator or the parent -- of the EWA if no nesting was detected. ------------------------- -- Find_Insertion_Node -- ------------------------- function Find_Insertion_Node return Node_Id is Par : Node_Id; begin -- Climb up the branches of a complex condition Par := N; while Nkind_In (Parent (Par), N_And_Then, N_Op_Not, N_Or_Else) loop Par := Parent (Par); end loop; return Par; end Find_Insertion_Node; -- Local variables Ins_Node : constant Node_Id := Find_Insertion_Node; Loc : constant Source_Ptr := Sloc (Decl); Obj_Id : constant Entity_Id := Defining_Identifier (Decl); Obj_Typ : constant Entity_Id := Etype (Obj_Id); Desig_Typ : Entity_Id; Expr : Node_Id; Ptr_Decl : Node_Id; Ptr_Id : Entity_Id; Temp_Decl : Node_Id; Temp_Id : Node_Id; -- Start of processing for Process_Transient_Object begin -- Step 1: Create the access type which provides a reference to the -- transient object. if Is_Access_Type (Obj_Typ) then Desig_Typ := Directly_Designated_Type (Obj_Typ); else Desig_Typ := Obj_Typ; end if; -- Generate: -- Ann : access [all] <Desig_Typ>; Ptr_Id := Make_Temporary (Loc, 'A'); Ptr_Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Ptr_Id, Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => Ekind (Obj_Typ) = E_General_Access_Type, Subtype_Indication => New_Reference_To (Desig_Typ, Loc))); Insert_Action (Ins_Node, Ptr_Decl); Analyze (Ptr_Decl); -- Step 2: Create a temporary which acts as a hook to the transient -- object. Generate: -- Temp : Ptr_Id := null; Temp_Id := Make_Temporary (Loc, 'T'); Temp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp_Id, Object_Definition => New_Reference_To (Ptr_Id, Loc)); Insert_Action (Ins_Node, Temp_Decl); Analyze (Temp_Decl); -- Mark this temporary as created for the purposes of exporting the -- transient declaration out of the Actions list. This signals the -- machinery in Build_Finalizer to recognize this special case. Set_Return_Flag_Or_Transient_Decl (Temp_Id, Decl); -- Step 3: Hook the transient object to the temporary if Is_Access_Type (Obj_Typ) then Expr := Convert_To (Ptr_Id, New_Reference_To (Obj_Id, Loc)); else Expr := Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Obj_Id, Loc), Attribute_Name => Name_Unrestricted_Access); end if; -- Generate: -- Temp := Ptr_Id (Obj_Id); -- <or> -- Temp := Obj_Id'Unrestricted_Access; Insert_After_And_Analyze (Decl, Make_Assignment_Statement (Loc, Name => New_Reference_To (Temp_Id, Loc), Expression => Expr)); end Process_Transient_Object; -- Local variables Decl : Node_Id; -- Start of processing for Expand_N_Expression_With_Actions begin Decl := First (Actions (N)); while Present (Decl) loop if Nkind (Decl) = N_Object_Declaration and then Is_Finalizable_Transient (Decl, N) then Process_Transient_Object (Decl); end if; Next (Decl); end loop; end Expand_N_Expression_With_Actions; ----------------- -- Expand_N_In -- ----------------- procedure Expand_N_In (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Restyp : constant Entity_Id := Etype (N); Lop : constant Node_Id := Left_Opnd (N); Rop : constant Node_Id := Right_Opnd (N); Static : constant Boolean := Is_OK_Static_Expression (N); Ltyp : Entity_Id; Rtyp : Entity_Id; procedure Substitute_Valid_Check; -- Replaces node N by Lop'Valid. This is done when we have an explicit -- test for the left operand being in range of its subtype. ---------------------------- -- Substitute_Valid_Check -- ---------------------------- procedure Substitute_Valid_Check is begin Rewrite (N, Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Lop), Attribute_Name => Name_Valid)); Analyze_And_Resolve (N, Restyp); Error_Msg_N ("?explicit membership test may be optimized away", N); Error_Msg_N -- CODEFIX ("\?use ''Valid attribute instead", N); return; end Substitute_Valid_Check; -- Start of processing for Expand_N_In begin -- If set membership case, expand with separate procedure if Present (Alternatives (N)) then Expand_Set_Membership (N); return; end if; -- Not set membership, proceed with expansion Ltyp := Etype (Left_Opnd (N)); Rtyp := Etype (Right_Opnd (N)); -- Check case of explicit test for an expression in range of its -- subtype. This is suspicious usage and we replace it with a 'Valid -- test and give a warning. For floating point types however, this is a -- standard way to check for finite numbers, and using 'Valid would -- typically be a pessimization. Also skip this test for predicated -- types, since it is perfectly reasonable to check if a value meets -- its predicate. if Is_Scalar_Type (Ltyp) and then not Is_Floating_Point_Type (Ltyp) and then Nkind (Rop) in N_Has_Entity and then Ltyp = Entity (Rop) and then Comes_From_Source (N) and then VM_Target = No_VM and then not (Is_Discrete_Type (Ltyp) and then Present (Predicate_Function (Ltyp))) then Substitute_Valid_Check; return; end if; -- Do validity check on operands if Validity_Checks_On and Validity_Check_Operands then Ensure_Valid (Left_Opnd (N)); Validity_Check_Range (Right_Opnd (N)); end if; -- Case of explicit range if Nkind (Rop) = N_Range then declare Lo : constant Node_Id := Low_Bound (Rop); Hi : constant Node_Id := High_Bound (Rop); Lo_Orig : constant Node_Id := Original_Node (Lo); Hi_Orig : constant Node_Id := Original_Node (Hi); Lcheck : Compare_Result; Ucheck : Compare_Result; Warn1 : constant Boolean := Constant_Condition_Warnings and then Comes_From_Source (N) and then not In_Instance; -- This must be true for any of the optimization warnings, we -- clearly want to give them only for source with the flag on. We -- also skip these warnings in an instance since it may be the -- case that different instantiations have different ranges. Warn2 : constant Boolean := Warn1 and then Nkind (Original_Node (Rop)) = N_Range and then Is_Integer_Type (Etype (Lo)); -- For the case where only one bound warning is elided, we also -- insist on an explicit range and an integer type. The reason is -- that the use of enumeration ranges including an end point is -- common, as is the use of a subtype name, one of whose bounds is -- the same as the type of the expression. begin -- If test is explicit x'First .. x'Last, replace by valid check -- Could use some individual comments for this complex test ??? if Is_Scalar_Type (Ltyp) and then Nkind (Lo_Orig) = N_Attribute_Reference and then Attribute_Name (Lo_Orig) = Name_First and then Nkind (Prefix (Lo_Orig)) in N_Has_Entity and then Entity (Prefix (Lo_Orig)) = Ltyp and then Nkind (Hi_Orig) = N_Attribute_Reference and then Attribute_Name (Hi_Orig) = Name_Last and then Nkind (Prefix (Hi_Orig)) in N_Has_Entity and then Entity (Prefix (Hi_Orig)) = Ltyp and then Comes_From_Source (N) and then VM_Target = No_VM then Substitute_Valid_Check; goto Leave; end if; -- If bounds of type are known at compile time, and the end points -- are known at compile time and identical, this is another case -- for substituting a valid test. We only do this for discrete -- types, since it won't arise in practice for float types. if Comes_From_Source (N) and then Is_Discrete_Type (Ltyp) and then Compile_Time_Known_Value (Type_High_Bound (Ltyp)) and then Compile_Time_Known_Value (Type_Low_Bound (Ltyp)) and then Compile_Time_Known_Value (Lo) and then Compile_Time_Known_Value (Hi) and then Expr_Value (Type_High_Bound (Ltyp)) = Expr_Value (Hi) and then Expr_Value (Type_Low_Bound (Ltyp)) = Expr_Value (Lo) -- Kill warnings in instances, since they may be cases where we -- have a test in the generic that makes sense with some types -- and not with other types. and then not In_Instance then Substitute_Valid_Check; goto Leave; end if; -- If we have an explicit range, do a bit of optimization based on -- range analysis (we may be able to kill one or both checks). Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => False); Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => False); -- If either check is known to fail, replace result by False since -- the other check does not matter. Preserve the static flag for -- legality checks, because we are constant-folding beyond RM 4.9. if Lcheck = LT or else Ucheck = GT then if Warn1 then Error_Msg_N ("?range test optimized away", N); Error_Msg_N ("\?value is known to be out of range", N); end if; Rewrite (N, New_Reference_To (Standard_False, Loc)); Analyze_And_Resolve (N, Restyp); Set_Is_Static_Expression (N, Static); goto Leave; -- If both checks are known to succeed, replace result by True, -- since we know we are in range. elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then if Warn1 then Error_Msg_N ("?range test optimized away", N); Error_Msg_N ("\?value is known to be in range", N); end if; Rewrite (N, New_Reference_To (Standard_True, Loc)); Analyze_And_Resolve (N, Restyp); Set_Is_Static_Expression (N, Static); goto Leave; -- If lower bound check succeeds and upper bound check is not -- known to succeed or fail, then replace the range check with -- a comparison against the upper bound. elsif Lcheck in Compare_GE then if Warn2 and then not In_Instance then Error_Msg_N ("?lower bound test optimized away", Lo); Error_Msg_N ("\?value is known to be in range", Lo); end if; Rewrite (N, Make_Op_Le (Loc, Left_Opnd => Lop, Right_Opnd => High_Bound (Rop))); Analyze_And_Resolve (N, Restyp); goto Leave; -- If upper bound check succeeds and lower bound check is not -- known to succeed or fail, then replace the range check with -- a comparison against the lower bound. elsif Ucheck in Compare_LE then if Warn2 and then not In_Instance then Error_Msg_N ("?upper bound test optimized away", Hi); Error_Msg_N ("\?value is known to be in range", Hi); end if; Rewrite (N, Make_Op_Ge (Loc, Left_Opnd => Lop, Right_Opnd => Low_Bound (Rop))); Analyze_And_Resolve (N, Restyp); goto Leave; end if; -- We couldn't optimize away the range check, but there is one -- more issue. If we are checking constant conditionals, then we -- see if we can determine the outcome assuming everything is -- valid, and if so give an appropriate warning. if Warn1 and then not Assume_No_Invalid_Values then Lcheck := Compile_Time_Compare (Lop, Lo, Assume_Valid => True); Ucheck := Compile_Time_Compare (Lop, Hi, Assume_Valid => True); -- Result is out of range for valid value if Lcheck = LT or else Ucheck = GT then Error_Msg_N ("?value can only be in range if it is invalid", N); -- Result is in range for valid value elsif Lcheck in Compare_GE and then Ucheck in Compare_LE then Error_Msg_N ("?value can only be out of range if it is invalid", N); -- Lower bound check succeeds if value is valid elsif Warn2 and then Lcheck in Compare_GE then Error_Msg_N ("?lower bound check only fails if it is invalid", Lo); -- Upper bound check succeeds if value is valid elsif Warn2 and then Ucheck in Compare_LE then Error_Msg_N ("?upper bound check only fails for invalid values", Hi); end if; end if; end; -- For all other cases of an explicit range, nothing to be done goto Leave; -- Here right operand is a subtype mark else declare Typ : Entity_Id := Etype (Rop); Is_Acc : constant Boolean := Is_Access_Type (Typ); Cond : Node_Id := Empty; New_N : Node_Id; Obj : Node_Id := Lop; SCIL_Node : Node_Id; begin Remove_Side_Effects (Obj); -- For tagged type, do tagged membership operation if Is_Tagged_Type (Typ) then -- No expansion will be performed when VM_Target, as the VM -- back-ends will handle the membership tests directly (tags -- are not explicitly represented in Java objects, so the -- normal tagged membership expansion is not what we want). if Tagged_Type_Expansion then Tagged_Membership (N, SCIL_Node, New_N); Rewrite (N, New_N); Analyze_And_Resolve (N, Restyp); -- Update decoration of relocated node referenced by the -- SCIL node. if Generate_SCIL and then Present (SCIL_Node) then Set_SCIL_Node (N, SCIL_Node); end if; end if; goto Leave; -- If type is scalar type, rewrite as x in t'First .. t'Last. -- This reason we do this is that the bounds may have the wrong -- type if they come from the original type definition. Also this -- way we get all the processing above for an explicit range. -- Don't do this for predicated types, since in this case we -- want to check the predicate! elsif Is_Scalar_Type (Typ) then if No (Predicate_Function (Typ)) then Rewrite (Rop, Make_Range (Loc, Low_Bound => Make_Attribute_Reference (Loc, Attribute_Name => Name_First, Prefix => New_Reference_To (Typ, Loc)), High_Bound => Make_Attribute_Reference (Loc, Attribute_Name => Name_Last, Prefix => New_Reference_To (Typ, Loc)))); Analyze_And_Resolve (N, Restyp); end if; goto Leave; -- Ada 2005 (AI-216): Program_Error is raised when evaluating -- a membership test if the subtype mark denotes a constrained -- Unchecked_Union subtype and the expression lacks inferable -- discriminants. elsif Is_Unchecked_Union (Base_Type (Typ)) and then Is_Constrained (Typ) and then not Has_Inferable_Discriminants (Lop) then Insert_Action (N, Make_Raise_Program_Error (Loc, Reason => PE_Unchecked_Union_Restriction)); -- Prevent Gigi from generating incorrect code by rewriting the -- test as False. Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); goto Leave; end if; -- Here we have a non-scalar type if Is_Acc then Typ := Designated_Type (Typ); end if; if not Is_Constrained (Typ) then Rewrite (N, New_Reference_To (Standard_True, Loc)); Analyze_And_Resolve (N, Restyp); -- For the constrained array case, we have to check the subscripts -- for an exact match if the lengths are non-zero (the lengths -- must match in any case). elsif Is_Array_Type (Typ) then Check_Subscripts : declare function Build_Attribute_Reference (E : Node_Id; Nam : Name_Id; Dim : Nat) return Node_Id; -- Build attribute reference E'Nam (Dim) ------------------------------- -- Build_Attribute_Reference -- ------------------------------- function Build_Attribute_Reference (E : Node_Id; Nam : Name_Id; Dim : Nat) return Node_Id is begin return Make_Attribute_Reference (Loc, Prefix => E, Attribute_Name => Nam, Expressions => New_List ( Make_Integer_Literal (Loc, Dim))); end Build_Attribute_Reference; -- Start of processing for Check_Subscripts begin for J in 1 .. Number_Dimensions (Typ) loop Evolve_And_Then (Cond, Make_Op_Eq (Loc, Left_Opnd => Build_Attribute_Reference (Duplicate_Subexpr_No_Checks (Obj), Name_First, J), Right_Opnd => Build_Attribute_Reference (New_Occurrence_Of (Typ, Loc), Name_First, J))); Evolve_And_Then (Cond, Make_Op_Eq (Loc, Left_Opnd => Build_Attribute_Reference (Duplicate_Subexpr_No_Checks (Obj), Name_Last, J), Right_Opnd => Build_Attribute_Reference (New_Occurrence_Of (Typ, Loc), Name_Last, J))); end loop; if Is_Acc then Cond := Make_Or_Else (Loc, Left_Opnd => Make_Op_Eq (Loc, Left_Opnd => Obj, Right_Opnd => Make_Null (Loc)), Right_Opnd => Cond); end if; Rewrite (N, Cond); Analyze_And_Resolve (N, Restyp); end Check_Subscripts; -- These are the cases where constraint checks may be required, -- e.g. records with possible discriminants else -- Expand the test into a series of discriminant comparisons. -- The expression that is built is the negation of the one that -- is used for checking discriminant constraints. Obj := Relocate_Node (Left_Opnd (N)); if Has_Discriminants (Typ) then Cond := Make_Op_Not (Loc, Right_Opnd => Build_Discriminant_Checks (Obj, Typ)); if Is_Acc then Cond := Make_Or_Else (Loc, Left_Opnd => Make_Op_Eq (Loc, Left_Opnd => Obj, Right_Opnd => Make_Null (Loc)), Right_Opnd => Cond); end if; else Cond := New_Occurrence_Of (Standard_True, Loc); end if; Rewrite (N, Cond); Analyze_And_Resolve (N, Restyp); end if; -- Ada 2012 (AI05-0149): Handle membership tests applied to an -- expression of an anonymous access type. This can involve an -- accessibility test and a tagged type membership test in the -- case of tagged designated types. if Ada_Version >= Ada_2012 and then Is_Acc and then Ekind (Ltyp) = E_Anonymous_Access_Type then declare Expr_Entity : Entity_Id := Empty; New_N : Node_Id; Param_Level : Node_Id; Type_Level : Node_Id; begin if Is_Entity_Name (Lop) then Expr_Entity := Param_Entity (Lop); if not Present (Expr_Entity) then Expr_Entity := Entity (Lop); end if; end if; -- If a conversion of the anonymous access value to the -- tested type would be illegal, then the result is False. if not Valid_Conversion (Lop, Rtyp, Lop, Report_Errs => False) then Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); Analyze_And_Resolve (N, Restyp); -- Apply an accessibility check if the access object has an -- associated access level and when the level of the type is -- less deep than the level of the access parameter. This -- only occur for access parameters and stand-alone objects -- of an anonymous access type. else if Present (Expr_Entity) and then Present (Effective_Extra_Accessibility (Expr_Entity)) and then UI_Gt (Object_Access_Level (Lop), Type_Access_Level (Rtyp)) then Param_Level := New_Occurrence_Of (Effective_Extra_Accessibility (Expr_Entity), Loc); Type_Level := Make_Integer_Literal (Loc, Type_Access_Level (Rtyp)); -- Return True only if the accessibility level of the -- expression entity is not deeper than the level of -- the tested access type. Rewrite (N, Make_And_Then (Loc, Left_Opnd => Relocate_Node (N), Right_Opnd => Make_Op_Le (Loc, Left_Opnd => Param_Level, Right_Opnd => Type_Level))); Analyze_And_Resolve (N); end if; -- If the designated type is tagged, do tagged membership -- operation. -- *** NOTE: we have to check not null before doing the -- tagged membership test (but maybe that can be done -- inside Tagged_Membership?). if Is_Tagged_Type (Typ) then Rewrite (N, Make_And_Then (Loc, Left_Opnd => Relocate_Node (N), Right_Opnd => Make_Op_Ne (Loc, Left_Opnd => Obj, Right_Opnd => Make_Null (Loc)))); -- No expansion will be performed when VM_Target, as -- the VM back-ends will handle the membership tests -- directly (tags are not explicitly represented in -- Java objects, so the normal tagged membership -- expansion is not what we want). if Tagged_Type_Expansion then -- Note that we have to pass Original_Node, because -- the membership test might already have been -- rewritten by earlier parts of membership test. Tagged_Membership (Original_Node (N), SCIL_Node, New_N); -- Update decoration of relocated node referenced -- by the SCIL node. if Generate_SCIL and then Present (SCIL_Node) then Set_SCIL_Node (New_N, SCIL_Node); end if; Rewrite (N, Make_And_Then (Loc, Left_Opnd => Relocate_Node (N), Right_Opnd => New_N)); Analyze_And_Resolve (N, Restyp); end if; end if; end if; end; end if; end; end if; -- At this point, we have done the processing required for the basic -- membership test, but not yet dealt with the predicate. <<Leave>> -- If a predicate is present, then we do the predicate test, but we -- most certainly want to omit this if we are within the predicate -- function itself, since otherwise we have an infinite recursion! declare PFunc : constant Entity_Id := Predicate_Function (Rtyp); begin if Present (PFunc) and then Current_Scope /= PFunc then Rewrite (N, Make_And_Then (Loc, Left_Opnd => Relocate_Node (N), Right_Opnd => Make_Predicate_Call (Rtyp, Lop))); -- Analyze new expression, mark left operand as analyzed to -- avoid infinite recursion adding predicate calls. Similarly, -- suppress further range checks on the call. Set_Analyzed (Left_Opnd (N)); Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); -- All done, skip attempt at compile time determination of result return; end if; end; end Expand_N_In; -------------------------------- -- Expand_N_Indexed_Component -- -------------------------------- procedure Expand_N_Indexed_Component (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); P : constant Node_Id := Prefix (N); T : constant Entity_Id := Etype (P); Atp : Entity_Id; begin -- A special optimization, if we have an indexed component that is -- selecting from a slice, then we can eliminate the slice, since, for -- example, x (i .. j)(k) is identical to x(k). The only difference is -- the range check required by the slice. The range check for the slice -- itself has already been generated. The range check for the -- subscripting operation is ensured by converting the subject to -- the subtype of the slice. -- This optimization not only generates better code, avoiding slice -- messing especially in the packed case, but more importantly bypasses -- some problems in handling this peculiar case, for example, the issue -- of dealing specially with object renamings. if Nkind (P) = N_Slice then Rewrite (N, Make_Indexed_Component (Loc, Prefix => Prefix (P), Expressions => New_List ( Convert_To (Etype (First_Index (Etype (P))), First (Expressions (N)))))); Analyze_And_Resolve (N, Typ); return; end if; -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place -- function, then additional actuals must be passed. if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function_Call (P) then Make_Build_In_Place_Call_In_Anonymous_Context (P); end if; -- If the prefix is an access type, then we unconditionally rewrite if -- as an explicit dereference. This simplifies processing for several -- cases, including packed array cases and certain cases in which checks -- must be generated. We used to try to do this only when it was -- necessary, but it cleans up the code to do it all the time. if Is_Access_Type (T) then Insert_Explicit_Dereference (P); Analyze_And_Resolve (P, Designated_Type (T)); Atp := Designated_Type (T); else Atp := T; end if; -- Generate index and validity checks Generate_Index_Checks (N); if Validity_Checks_On and then Validity_Check_Subscripts then Apply_Subscript_Validity_Checks (N); end if; -- If selecting from an array with atomic components, and atomic sync -- is not suppressed for this array type, set atomic sync flag. if (Has_Atomic_Components (Atp) and then not Atomic_Synchronization_Disabled (Atp)) or else (Is_Atomic (Typ) and then not Atomic_Synchronization_Disabled (Typ)) then Activate_Atomic_Synchronization (N); end if; -- All done for the non-packed case if not Is_Packed (Etype (Prefix (N))) then return; end if; -- For packed arrays that are not bit-packed (i.e. the case of an array -- with one or more index types with a non-contiguous enumeration type), -- we can always use the normal packed element get circuit. if not Is_Bit_Packed_Array (Etype (Prefix (N))) then Expand_Packed_Element_Reference (N); return; end if; -- For a reference to a component of a bit packed array, we have to -- convert it to a reference to the corresponding Packed_Array_Type. -- We only want to do this for simple references, and not for: -- Left side of assignment, or prefix of left side of assignment, or -- prefix of the prefix, to handle packed arrays of packed arrays, -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement -- Renaming objects in renaming associations -- This case is handled when a use of the renamed variable occurs -- Actual parameters for a procedure call -- This case is handled in Exp_Ch6.Expand_Actuals -- The second expression in a 'Read attribute reference -- The prefix of an address or bit or size attribute reference -- The following circuit detects these exceptions declare Child : Node_Id := N; Parnt : Node_Id := Parent (N); begin loop if Nkind (Parnt) = N_Unchecked_Expression then null; elsif Nkind_In (Parnt, N_Object_Renaming_Declaration, N_Procedure_Call_Statement) or else (Nkind (Parnt) = N_Parameter_Association and then Nkind (Parent (Parnt)) = N_Procedure_Call_Statement) then return; elsif Nkind (Parnt) = N_Attribute_Reference and then (Attribute_Name (Parnt) = Name_Address or else Attribute_Name (Parnt) = Name_Bit or else Attribute_Name (Parnt) = Name_Size) and then Prefix (Parnt) = Child then return; elsif Nkind (Parnt) = N_Assignment_Statement and then Name (Parnt) = Child then return; -- If the expression is an index of an indexed component, it must -- be expanded regardless of context. elsif Nkind (Parnt) = N_Indexed_Component and then Child /= Prefix (Parnt) then Expand_Packed_Element_Reference (N); return; elsif Nkind (Parent (Parnt)) = N_Assignment_Statement and then Name (Parent (Parnt)) = Parnt then return; elsif Nkind (Parnt) = N_Attribute_Reference and then Attribute_Name (Parnt) = Name_Read and then Next (First (Expressions (Parnt))) = Child then return; elsif Nkind_In (Parnt, N_Indexed_Component, N_Selected_Component) and then Prefix (Parnt) = Child then null; else Expand_Packed_Element_Reference (N); return; end if; -- Keep looking up tree for unchecked expression, or if we are the -- prefix of a possible assignment left side. Child := Parnt; Parnt := Parent (Child); end loop; end; end Expand_N_Indexed_Component; --------------------- -- Expand_N_Not_In -- --------------------- -- Replace a not in b by not (a in b) so that the expansions for (a in b) -- can be done. This avoids needing to duplicate this expansion code. procedure Expand_N_Not_In (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Cfs : constant Boolean := Comes_From_Source (N); begin Rewrite (N, Make_Op_Not (Loc, Right_Opnd => Make_In (Loc, Left_Opnd => Left_Opnd (N), Right_Opnd => Right_Opnd (N)))); -- If this is a set membership, preserve list of alternatives Set_Alternatives (Right_Opnd (N), Alternatives (Original_Node (N))); -- We want this to appear as coming from source if original does (see -- transformations in Expand_N_In). Set_Comes_From_Source (N, Cfs); Set_Comes_From_Source (Right_Opnd (N), Cfs); -- Now analyze transformed node Analyze_And_Resolve (N, Typ); end Expand_N_Not_In; ------------------- -- Expand_N_Null -- ------------------- -- The only replacement required is for the case of a null of a type that -- is an access to protected subprogram, or a subtype thereof. We represent -- such access values as a record, and so we must replace the occurrence of -- null by the equivalent record (with a null address and a null pointer in -- it), so that the backend creates the proper value. procedure Expand_N_Null (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Base_Type (Etype (N)); Agg : Node_Id; begin if Is_Access_Protected_Subprogram_Type (Typ) then Agg := Make_Aggregate (Loc, Expressions => New_List ( New_Occurrence_Of (RTE (RE_Null_Address), Loc), Make_Null (Loc))); Rewrite (N, Agg); Analyze_And_Resolve (N, Equivalent_Type (Typ)); -- For subsequent semantic analysis, the node must retain its type. -- Gigi in any case replaces this type by the corresponding record -- type before processing the node. Set_Etype (N, Typ); end if; exception when RE_Not_Available => return; end Expand_N_Null; --------------------- -- Expand_N_Op_Abs -- --------------------- procedure Expand_N_Op_Abs (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Expr : constant Node_Id := Right_Opnd (N); begin Unary_Op_Validity_Checks (N); -- Deal with software overflow checking if not Backend_Overflow_Checks_On_Target and then Is_Signed_Integer_Type (Etype (N)) and then Do_Overflow_Check (N) then -- The only case to worry about is when the argument is equal to the -- largest negative number, so what we do is to insert the check: -- [constraint_error when Expr = typ'Base'First] -- with the usual Duplicate_Subexpr use coding for expr Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Make_Op_Eq (Loc, Left_Opnd => Duplicate_Subexpr (Expr), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Base_Type (Etype (Expr)), Loc), Attribute_Name => Name_First)), Reason => CE_Overflow_Check_Failed)); end if; -- Vax floating-point types case if Vax_Float (Etype (N)) then Expand_Vax_Arith (N); end if; end Expand_N_Op_Abs; --------------------- -- Expand_N_Op_Add -- --------------------- procedure Expand_N_Op_Add (N : Node_Id) is Typ : constant Entity_Id := Etype (N); begin Binary_Op_Validity_Checks (N); -- N + 0 = 0 + N = N for integer types if Is_Integer_Type (Typ) then if Compile_Time_Known_Value (Right_Opnd (N)) and then Expr_Value (Right_Opnd (N)) = Uint_0 then Rewrite (N, Left_Opnd (N)); return; elsif Compile_Time_Known_Value (Left_Opnd (N)) and then Expr_Value (Left_Opnd (N)) = Uint_0 then Rewrite (N, Right_Opnd (N)); return; end if; end if; -- Arithmetic overflow checks for signed integer/fixed point types if Is_Signed_Integer_Type (Typ) or else Is_Fixed_Point_Type (Typ) then Apply_Arithmetic_Overflow_Check (N); return; -- Vax floating-point types case elsif Vax_Float (Typ) then Expand_Vax_Arith (N); end if; end Expand_N_Op_Add; --------------------- -- Expand_N_Op_And -- --------------------- procedure Expand_N_Op_And (N : Node_Id) is Typ : constant Entity_Id := Etype (N); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Etype (N)) then Expand_Boolean_Operator (N); elsif Is_Boolean_Type (Etype (N)) then Adjust_Condition (Left_Opnd (N)); Adjust_Condition (Right_Opnd (N)); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); elsif Is_Intrinsic_Subprogram (Entity (N)) then Expand_Intrinsic_Call (N, Entity (N)); end if; end Expand_N_Op_And; ------------------------ -- Expand_N_Op_Concat -- ------------------------ procedure Expand_N_Op_Concat (N : Node_Id) is Opnds : List_Id; -- List of operands to be concatenated Cnode : Node_Id; -- Node which is to be replaced by the result of concatenating the nodes -- in the list Opnds. begin -- Ensure validity of both operands Binary_Op_Validity_Checks (N); -- If we are the left operand of a concatenation higher up the tree, -- then do nothing for now, since we want to deal with a series of -- concatenations as a unit. if Nkind (Parent (N)) = N_Op_Concat and then N = Left_Opnd (Parent (N)) then return; end if; -- We get here with a concatenation whose left operand may be a -- concatenation itself with a consistent type. We need to process -- these concatenation operands from left to right, which means -- from the deepest node in the tree to the highest node. Cnode := N; while Nkind (Left_Opnd (Cnode)) = N_Op_Concat loop Cnode := Left_Opnd (Cnode); end loop; -- Now Cnode is the deepest concatenation, and its parents are the -- concatenation nodes above, so now we process bottom up, doing the -- operations. We gather a string that is as long as possible up to five -- operands. -- The outer loop runs more than once if more than one concatenation -- type is involved. Outer : loop Opnds := New_List (Left_Opnd (Cnode), Right_Opnd (Cnode)); Set_Parent (Opnds, N); -- The inner loop gathers concatenation operands Inner : while Cnode /= N and then Base_Type (Etype (Cnode)) = Base_Type (Etype (Parent (Cnode))) loop Cnode := Parent (Cnode); Append (Right_Opnd (Cnode), Opnds); end loop Inner; Expand_Concatenate (Cnode, Opnds); exit Outer when Cnode = N; Cnode := Parent (Cnode); end loop Outer; end Expand_N_Op_Concat; ------------------------ -- Expand_N_Op_Divide -- ------------------------ procedure Expand_N_Op_Divide (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Lopnd : constant Node_Id := Left_Opnd (N); Ropnd : constant Node_Id := Right_Opnd (N); Ltyp : constant Entity_Id := Etype (Lopnd); Rtyp : constant Entity_Id := Etype (Ropnd); Typ : Entity_Id := Etype (N); Rknow : constant Boolean := Is_Integer_Type (Typ) and then Compile_Time_Known_Value (Ropnd); Rval : Uint; begin Binary_Op_Validity_Checks (N); if Rknow then Rval := Expr_Value (Ropnd); end if; -- N / 1 = N for integer types if Rknow and then Rval = Uint_1 then Rewrite (N, Lopnd); return; end if; -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that -- Is_Power_Of_2_For_Shift is set means that we know that our left -- operand is an unsigned integer, as required for this to work. if Nkind (Ropnd) = N_Op_Expon and then Is_Power_Of_2_For_Shift (Ropnd) -- We cannot do this transformation in configurable run time mode if we -- have 64-bit integers and long shifts are not available. and then (Esize (Ltyp) <= 32 or else Support_Long_Shifts_On_Target) then Rewrite (N, Make_Op_Shift_Right (Loc, Left_Opnd => Lopnd, Right_Opnd => Convert_To (Standard_Natural, Right_Opnd (Ropnd)))); Analyze_And_Resolve (N, Typ); return; end if; -- Do required fixup of universal fixed operation if Typ = Universal_Fixed then Fixup_Universal_Fixed_Operation (N); Typ := Etype (N); end if; -- Divisions with fixed-point results if Is_Fixed_Point_Type (Typ) then -- No special processing if Treat_Fixed_As_Integer is set, since -- from a semantic point of view such operations are simply integer -- operations and will be treated that way. if not Treat_Fixed_As_Integer (N) then if Is_Integer_Type (Rtyp) then Expand_Divide_Fixed_By_Integer_Giving_Fixed (N); else Expand_Divide_Fixed_By_Fixed_Giving_Fixed (N); end if; end if; -- Other cases of division of fixed-point operands. Again we exclude the -- case where Treat_Fixed_As_Integer is set. elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp)) and then not Treat_Fixed_As_Integer (N) then if Is_Integer_Type (Typ) then Expand_Divide_Fixed_By_Fixed_Giving_Integer (N); else pragma Assert (Is_Floating_Point_Type (Typ)); Expand_Divide_Fixed_By_Fixed_Giving_Float (N); end if; -- Mixed-mode operations can appear in a non-static universal context, -- in which case the integer argument must be converted explicitly. elsif Typ = Universal_Real and then Is_Integer_Type (Rtyp) then Rewrite (Ropnd, Convert_To (Universal_Real, Relocate_Node (Ropnd))); Analyze_And_Resolve (Ropnd, Universal_Real); elsif Typ = Universal_Real and then Is_Integer_Type (Ltyp) then Rewrite (Lopnd, Convert_To (Universal_Real, Relocate_Node (Lopnd))); Analyze_And_Resolve (Lopnd, Universal_Real); -- Non-fixed point cases, do integer zero divide and overflow checks elsif Is_Integer_Type (Typ) then Apply_Divide_Check (N); -- Deal with Vax_Float elsif Vax_Float (Typ) then Expand_Vax_Arith (N); return; end if; end Expand_N_Op_Divide; -------------------- -- Expand_N_Op_Eq -- -------------------- procedure Expand_N_Op_Eq (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Lhs : constant Node_Id := Left_Opnd (N); Rhs : constant Node_Id := Right_Opnd (N); Bodies : constant List_Id := New_List; A_Typ : constant Entity_Id := Etype (Lhs); Typl : Entity_Id := A_Typ; Op_Name : Entity_Id; Prim : Elmt_Id; procedure Build_Equality_Call (Eq : Entity_Id); -- If a constructed equality exists for the type or for its parent, -- build and analyze call, adding conversions if the operation is -- inherited. function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean; -- Determines whether a type has a subcomponent of an unconstrained -- Unchecked_Union subtype. Typ is a record type. ------------------------- -- Build_Equality_Call -- ------------------------- procedure Build_Equality_Call (Eq : Entity_Id) is Op_Type : constant Entity_Id := Etype (First_Formal (Eq)); L_Exp : Node_Id := Relocate_Node (Lhs); R_Exp : Node_Id := Relocate_Node (Rhs); begin if Base_Type (Op_Type) /= Base_Type (A_Typ) and then not Is_Class_Wide_Type (A_Typ) then L_Exp := OK_Convert_To (Op_Type, L_Exp); R_Exp := OK_Convert_To (Op_Type, R_Exp); end if; -- If we have an Unchecked_Union, we need to add the inferred -- discriminant values as actuals in the function call. At this -- point, the expansion has determined that both operands have -- inferable discriminants. if Is_Unchecked_Union (Op_Type) then declare Lhs_Type : constant Node_Id := Etype (L_Exp); Rhs_Type : constant Node_Id := Etype (R_Exp); Lhs_Discr_Val : Node_Id; Rhs_Discr_Val : Node_Id; begin -- Per-object constrained selected components require special -- attention. If the enclosing scope of the component is an -- Unchecked_Union, we cannot reference its discriminants -- directly. This is why we use the two extra parameters of -- the equality function of the enclosing Unchecked_Union. -- type UU_Type (Discr : Integer := 0) is -- . . . -- end record; -- pragma Unchecked_Union (UU_Type); -- 1. Unchecked_Union enclosing record: -- type Enclosing_UU_Type (Discr : Integer := 0) is record -- . . . -- Comp : UU_Type (Discr); -- . . . -- end Enclosing_UU_Type; -- pragma Unchecked_Union (Enclosing_UU_Type); -- Obj1 : Enclosing_UU_Type; -- Obj2 : Enclosing_UU_Type (1); -- [. . .] Obj1 = Obj2 [. . .] -- Generated code: -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then -- A and B are the formal parameters of the equality function -- of Enclosing_UU_Type. The function always has two extra -- formals to capture the inferred discriminant values. -- 2. Non-Unchecked_Union enclosing record: -- type -- Enclosing_Non_UU_Type (Discr : Integer := 0) -- is record -- . . . -- Comp : UU_Type (Discr); -- . . . -- end Enclosing_Non_UU_Type; -- Obj1 : Enclosing_Non_UU_Type; -- Obj2 : Enclosing_Non_UU_Type (1); -- ... Obj1 = Obj2 ... -- Generated code: -- if not (uu_typeEQ (obj1.comp, obj2.comp, -- obj1.discr, obj2.discr)) then -- In this case we can directly reference the discriminants of -- the enclosing record. -- Lhs of equality if Nkind (Lhs) = N_Selected_Component and then Has_Per_Object_Constraint (Entity (Selector_Name (Lhs))) then -- Enclosing record is an Unchecked_Union, use formal A if Is_Unchecked_Union (Scope (Entity (Selector_Name (Lhs)))) then Lhs_Discr_Val := Make_Identifier (Loc, Name_A); -- Enclosing record is of a non-Unchecked_Union type, it is -- possible to reference the discriminant. else Lhs_Discr_Val := Make_Selected_Component (Loc, Prefix => Prefix (Lhs), Selector_Name => New_Copy (Get_Discriminant_Value (First_Discriminant (Lhs_Type), Lhs_Type, Stored_Constraint (Lhs_Type)))); end if; -- Comment needed here ??? else -- Infer the discriminant value Lhs_Discr_Val := New_Copy (Get_Discriminant_Value (First_Discriminant (Lhs_Type), Lhs_Type, Stored_Constraint (Lhs_Type))); end if; -- Rhs of equality if Nkind (Rhs) = N_Selected_Component and then Has_Per_Object_Constraint (Entity (Selector_Name (Rhs))) then if Is_Unchecked_Union (Scope (Entity (Selector_Name (Rhs)))) then Rhs_Discr_Val := Make_Identifier (Loc, Name_B); else Rhs_Discr_Val := Make_Selected_Component (Loc, Prefix => Prefix (Rhs), Selector_Name => New_Copy (Get_Discriminant_Value ( First_Discriminant (Rhs_Type), Rhs_Type, Stored_Constraint (Rhs_Type)))); end if; else Rhs_Discr_Val := New_Copy (Get_Discriminant_Value ( First_Discriminant (Rhs_Type), Rhs_Type, Stored_Constraint (Rhs_Type))); end if; Rewrite (N, Make_Function_Call (Loc, Name => New_Reference_To (Eq, Loc), Parameter_Associations => New_List ( L_Exp, R_Exp, Lhs_Discr_Val, Rhs_Discr_Val))); end; -- Normal case, not an unchecked union else Rewrite (N, Make_Function_Call (Loc, Name => New_Reference_To (Eq, Loc), Parameter_Associations => New_List (L_Exp, R_Exp))); end if; Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); end Build_Equality_Call; ------------------------------------ -- Has_Unconstrained_UU_Component -- ------------------------------------ function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean is Tdef : constant Node_Id := Type_Definition (Declaration_Node (Base_Type (Typ))); Clist : Node_Id; Vpart : Node_Id; function Component_Is_Unconstrained_UU (Comp : Node_Id) return Boolean; -- Determines whether the subtype of the component is an -- unconstrained Unchecked_Union. function Variant_Is_Unconstrained_UU (Variant : Node_Id) return Boolean; -- Determines whether a component of the variant has an unconstrained -- Unchecked_Union subtype. ----------------------------------- -- Component_Is_Unconstrained_UU -- ----------------------------------- function Component_Is_Unconstrained_UU (Comp : Node_Id) return Boolean is begin if Nkind (Comp) /= N_Component_Declaration then return False; end if; declare Sindic : constant Node_Id := Subtype_Indication (Component_Definition (Comp)); begin -- Unconstrained nominal type. In the case of a constraint -- present, the node kind would have been N_Subtype_Indication. if Nkind (Sindic) = N_Identifier then return Is_Unchecked_Union (Base_Type (Etype (Sindic))); end if; return False; end; end Component_Is_Unconstrained_UU; --------------------------------- -- Variant_Is_Unconstrained_UU -- --------------------------------- function Variant_Is_Unconstrained_UU (Variant : Node_Id) return Boolean is Clist : constant Node_Id := Component_List (Variant); begin if Is_Empty_List (Component_Items (Clist)) then return False; end if; -- We only need to test one component declare Comp : Node_Id := First (Component_Items (Clist)); begin while Present (Comp) loop if Component_Is_Unconstrained_UU (Comp) then return True; end if; Next (Comp); end loop; end; -- None of the components withing the variant were of -- unconstrained Unchecked_Union type. return False; end Variant_Is_Unconstrained_UU; -- Start of processing for Has_Unconstrained_UU_Component begin if Null_Present (Tdef) then return False; end if; Clist := Component_List (Tdef); Vpart := Variant_Part (Clist); -- Inspect available components if Present (Component_Items (Clist)) then declare Comp : Node_Id := First (Component_Items (Clist)); begin while Present (Comp) loop -- One component is sufficient if Component_Is_Unconstrained_UU (Comp) then return True; end if; Next (Comp); end loop; end; end if; -- Inspect available components withing variants if Present (Vpart) then declare Variant : Node_Id := First (Variants (Vpart)); begin while Present (Variant) loop -- One component within a variant is sufficient if Variant_Is_Unconstrained_UU (Variant) then return True; end if; Next (Variant); end loop; end; end if; -- Neither the available components, nor the components inside the -- variant parts were of an unconstrained Unchecked_Union subtype. return False; end Has_Unconstrained_UU_Component; -- Start of processing for Expand_N_Op_Eq begin Binary_Op_Validity_Checks (N); if Ekind (Typl) = E_Private_Type then Typl := Underlying_Type (Typl); elsif Ekind (Typl) = E_Private_Subtype then Typl := Underlying_Type (Base_Type (Typl)); else null; end if; -- It may happen in error situations that the underlying type is not -- set. The error will be detected later, here we just defend the -- expander code. if No (Typl) then return; end if; Typl := Base_Type (Typl); -- Boolean types (requiring handling of non-standard case) if Is_Boolean_Type (Typl) then Adjust_Condition (Left_Opnd (N)); Adjust_Condition (Right_Opnd (N)); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); -- Array types elsif Is_Array_Type (Typl) then -- If we are doing full validity checking, and it is possible for the -- array elements to be invalid then expand out array comparisons to -- make sure that we check the array elements. if Validity_Check_Operands and then not Is_Known_Valid (Component_Type (Typl)) then declare Save_Force_Validity_Checks : constant Boolean := Force_Validity_Checks; begin Force_Validity_Checks := True; Rewrite (N, Expand_Array_Equality (N, Relocate_Node (Lhs), Relocate_Node (Rhs), Bodies, Typl)); Insert_Actions (N, Bodies); Analyze_And_Resolve (N, Standard_Boolean); Force_Validity_Checks := Save_Force_Validity_Checks; end; -- Packed case where both operands are known aligned elsif Is_Bit_Packed_Array (Typl) and then not Is_Possibly_Unaligned_Object (Lhs) and then not Is_Possibly_Unaligned_Object (Rhs) then Expand_Packed_Eq (N); -- Where the component type is elementary we can use a block bit -- comparison (if supported on the target) exception in the case -- of floating-point (negative zero issues require element by -- element comparison), and atomic types (where we must be sure -- to load elements independently) and possibly unaligned arrays. elsif Is_Elementary_Type (Component_Type (Typl)) and then not Is_Floating_Point_Type (Component_Type (Typl)) and then not Is_Atomic (Component_Type (Typl)) and then not Is_Possibly_Unaligned_Object (Lhs) and then not Is_Possibly_Unaligned_Object (Rhs) and then Support_Composite_Compare_On_Target then null; -- For composite and floating-point cases, expand equality loop to -- make sure of using proper comparisons for tagged types, and -- correctly handling the floating-point case. else Rewrite (N, Expand_Array_Equality (N, Relocate_Node (Lhs), Relocate_Node (Rhs), Bodies, Typl)); Insert_Actions (N, Bodies, Suppress => All_Checks); Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); end if; -- Record Types elsif Is_Record_Type (Typl) then -- For tagged types, use the primitive "=" if Is_Tagged_Type (Typl) then -- No need to do anything else compiling under restriction -- No_Dispatching_Calls. During the semantic analysis we -- already notified such violation. if Restriction_Active (No_Dispatching_Calls) then return; end if; -- If this is derived from an untagged private type completed with -- a tagged type, it does not have a full view, so we use the -- primitive operations of the private type. This check should no -- longer be necessary when these types get their full views??? if Is_Private_Type (A_Typ) and then not Is_Tagged_Type (A_Typ) and then Is_Derived_Type (A_Typ) and then No (Full_View (A_Typ)) then -- Search for equality operation, checking that the operands -- have the same type. Note that we must find a matching entry, -- or something is very wrong! Prim := First_Elmt (Collect_Primitive_Operations (A_Typ)); while Present (Prim) loop exit when Chars (Node (Prim)) = Name_Op_Eq and then Etype (First_Formal (Node (Prim))) = Etype (Next_Formal (First_Formal (Node (Prim)))) and then Base_Type (Etype (Node (Prim))) = Standard_Boolean; Next_Elmt (Prim); end loop; pragma Assert (Present (Prim)); Op_Name := Node (Prim); -- Find the type's predefined equality or an overriding -- user- defined equality. The reason for not simply calling -- Find_Prim_Op here is that there may be a user-defined -- overloaded equality op that precedes the equality that we want, -- so we have to explicitly search (e.g., there could be an -- equality with two different parameter types). else if Is_Class_Wide_Type (Typl) then Typl := Root_Type (Typl); end if; Prim := First_Elmt (Primitive_Operations (Typl)); while Present (Prim) loop exit when Chars (Node (Prim)) = Name_Op_Eq and then Etype (First_Formal (Node (Prim))) = Etype (Next_Formal (First_Formal (Node (Prim)))) and then Base_Type (Etype (Node (Prim))) = Standard_Boolean; Next_Elmt (Prim); end loop; pragma Assert (Present (Prim)); Op_Name := Node (Prim); end if; Build_Equality_Call (Op_Name); -- Ada 2005 (AI-216): Program_Error is raised when evaluating the -- predefined equality operator for a type which has a subcomponent -- of an Unchecked_Union type whose nominal subtype is unconstrained. elsif Has_Unconstrained_UU_Component (Typl) then Insert_Action (N, Make_Raise_Program_Error (Loc, Reason => PE_Unchecked_Union_Restriction)); -- Prevent Gigi from generating incorrect code by rewriting the -- equality as a standard False. Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); elsif Is_Unchecked_Union (Typl) then -- If we can infer the discriminants of the operands, we make a -- call to the TSS equality function. if Has_Inferable_Discriminants (Lhs) and then Has_Inferable_Discriminants (Rhs) then Build_Equality_Call (TSS (Root_Type (Typl), TSS_Composite_Equality)); else -- Ada 2005 (AI-216): Program_Error is raised when evaluating -- the predefined equality operator for an Unchecked_Union type -- if either of the operands lack inferable discriminants. Insert_Action (N, Make_Raise_Program_Error (Loc, Reason => PE_Unchecked_Union_Restriction)); -- Prevent Gigi from generating incorrect code by rewriting -- the equality as a standard False. Rewrite (N, New_Occurrence_Of (Standard_False, Loc)); end if; -- If a type support function is present (for complex cases), use it elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then Build_Equality_Call (TSS (Root_Type (Typl), TSS_Composite_Equality)); -- Otherwise expand the component by component equality. Note that -- we never use block-bit comparisons for records, because of the -- problems with gaps. The backend will often be able to recombine -- the separate comparisons that we generate here. else Remove_Side_Effects (Lhs); Remove_Side_Effects (Rhs); Rewrite (N, Expand_Record_Equality (N, Typl, Lhs, Rhs, Bodies)); Insert_Actions (N, Bodies, Suppress => All_Checks); Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks); end if; end if; -- Test if result is known at compile time Rewrite_Comparison (N); -- If we still have comparison for Vax_Float, process it if Vax_Float (Typl) and then Nkind (N) in N_Op_Compare then Expand_Vax_Comparison (N); return; end if; Optimize_Length_Comparison (N); end Expand_N_Op_Eq; ----------------------- -- Expand_N_Op_Expon -- ----------------------- procedure Expand_N_Op_Expon (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Rtyp : constant Entity_Id := Root_Type (Typ); Base : constant Node_Id := Relocate_Node (Left_Opnd (N)); Bastyp : constant Node_Id := Etype (Base); Exp : constant Node_Id := Relocate_Node (Right_Opnd (N)); Exptyp : constant Entity_Id := Etype (Exp); Ovflo : constant Boolean := Do_Overflow_Check (N); Expv : Uint; Xnode : Node_Id; Temp : Node_Id; Rent : RE_Id; Ent : Entity_Id; Etyp : Entity_Id; begin Binary_Op_Validity_Checks (N); -- CodePeer and GNATprove want to see the unexpanded N_Op_Expon node if CodePeer_Mode or Alfa_Mode then return; end if; -- If either operand is of a private type, then we have the use of an -- intrinsic operator, and we get rid of the privateness, by using root -- types of underlying types for the actual operation. Otherwise the -- private types will cause trouble if we expand multiplications or -- shifts etc. We also do this transformation if the result type is -- different from the base type. if Is_Private_Type (Etype (Base)) or else Is_Private_Type (Typ) or else Is_Private_Type (Exptyp) or else Rtyp /= Root_Type (Bastyp) then declare Bt : constant Entity_Id := Root_Type (Underlying_Type (Bastyp)); Et : constant Entity_Id := Root_Type (Underlying_Type (Exptyp)); begin Rewrite (N, Unchecked_Convert_To (Typ, Make_Op_Expon (Loc, Left_Opnd => Unchecked_Convert_To (Bt, Base), Right_Opnd => Unchecked_Convert_To (Et, Exp)))); Analyze_And_Resolve (N, Typ); return; end; end if; -- Test for case of known right argument if Compile_Time_Known_Value (Exp) then Expv := Expr_Value (Exp); -- We only fold small non-negative exponents. You might think we -- could fold small negative exponents for the real case, but we -- can't because we are required to raise Constraint_Error for -- the case of 0.0 ** (negative) even if Machine_Overflows = False. -- See ACVC test C4A012B. if Expv >= 0 and then Expv <= 4 then -- X ** 0 = 1 (or 1.0) if Expv = 0 then -- Call Remove_Side_Effects to ensure that any side effects -- in the ignored left operand (in particular function calls -- to user defined functions) are properly executed. Remove_Side_Effects (Base); if Ekind (Typ) in Integer_Kind then Xnode := Make_Integer_Literal (Loc, Intval => 1); else Xnode := Make_Real_Literal (Loc, Ureal_1); end if; -- X ** 1 = X elsif Expv = 1 then Xnode := Base; -- X ** 2 = X * X elsif Expv = 2 then Xnode := Make_Op_Multiply (Loc, Left_Opnd => Duplicate_Subexpr (Base), Right_Opnd => Duplicate_Subexpr_No_Checks (Base)); -- X ** 3 = X * X * X elsif Expv = 3 then Xnode := Make_Op_Multiply (Loc, Left_Opnd => Make_Op_Multiply (Loc, Left_Opnd => Duplicate_Subexpr (Base), Right_Opnd => Duplicate_Subexpr_No_Checks (Base)), Right_Opnd => Duplicate_Subexpr_No_Checks (Base)); -- X ** 4 -> -- En : constant base'type := base * base; -- ... -- En * En else -- Expv = 4 Temp := Make_Temporary (Loc, 'E', Base); Insert_Actions (N, New_List ( Make_Object_Declaration (Loc, Defining_Identifier => Temp, Constant_Present => True, Object_Definition => New_Reference_To (Typ, Loc), Expression => Make_Op_Multiply (Loc, Left_Opnd => Duplicate_Subexpr (Base), Right_Opnd => Duplicate_Subexpr_No_Checks (Base))))); Xnode := Make_Op_Multiply (Loc, Left_Opnd => New_Reference_To (Temp, Loc), Right_Opnd => New_Reference_To (Temp, Loc)); end if; Rewrite (N, Xnode); Analyze_And_Resolve (N, Typ); return; end if; end if; -- Case of (2 ** expression) appearing as an argument of an integer -- multiplication, or as the right argument of a division of a non- -- negative integer. In such cases we leave the node untouched, setting -- the flag Is_Natural_Power_Of_2_for_Shift set, then the expansion -- of the higher level node converts it into a shift. -- Another case is 2 ** N in any other context. We simply convert -- this to 1 * 2 ** N, and then the above transformation applies. -- Note: this transformation is not applicable for a modular type with -- a non-binary modulus in the multiplication case, since we get a wrong -- result if the shift causes an overflow before the modular reduction. if Nkind (Base) = N_Integer_Literal and then Intval (Base) = 2 and then Is_Integer_Type (Root_Type (Exptyp)) and then Esize (Root_Type (Exptyp)) <= Esize (Standard_Integer) and then Is_Unsigned_Type (Exptyp) and then not Ovflo then -- First the multiply and divide cases if Nkind_In (Parent (N), N_Op_Divide, N_Op_Multiply) then declare P : constant Node_Id := Parent (N); L : constant Node_Id := Left_Opnd (P); R : constant Node_Id := Right_Opnd (P); begin if (Nkind (P) = N_Op_Multiply and then not Non_Binary_Modulus (Typ) and then ((Is_Integer_Type (Etype (L)) and then R = N) or else (Is_Integer_Type (Etype (R)) and then L = N)) and then not Do_Overflow_Check (P)) or else (Nkind (P) = N_Op_Divide and then Is_Integer_Type (Etype (L)) and then Is_Unsigned_Type (Etype (L)) and then R = N and then not Do_Overflow_Check (P)) then Set_Is_Power_Of_2_For_Shift (N); return; end if; end; -- Now the other cases elsif not Non_Binary_Modulus (Typ) then Rewrite (N, Make_Op_Multiply (Loc, Left_Opnd => Make_Integer_Literal (Loc, 1), Right_Opnd => Relocate_Node (N))); Analyze_And_Resolve (N, Typ); return; end if; end if; -- Fall through if exponentiation must be done using a runtime routine -- First deal with modular case if Is_Modular_Integer_Type (Rtyp) then -- Non-binary case, we call the special exponentiation routine for -- the non-binary case, converting the argument to Long_Long_Integer -- and passing the modulus value. Then the result is converted back -- to the base type. if Non_Binary_Modulus (Rtyp) then Rewrite (N, Convert_To (Typ, Make_Function_Call (Loc, Name => New_Reference_To (RTE (RE_Exp_Modular), Loc), Parameter_Associations => New_List ( Convert_To (Standard_Integer, Base), Make_Integer_Literal (Loc, Modulus (Rtyp)), Exp)))); -- Binary case, in this case, we call one of two routines, either the -- unsigned integer case, or the unsigned long long integer case, -- with a final "and" operation to do the required mod. else if UI_To_Int (Esize (Rtyp)) <= Standard_Integer_Size then Ent := RTE (RE_Exp_Unsigned); else Ent := RTE (RE_Exp_Long_Long_Unsigned); end if; Rewrite (N, Convert_To (Typ, Make_Op_And (Loc, Left_Opnd => Make_Function_Call (Loc, Name => New_Reference_To (Ent, Loc), Parameter_Associations => New_List ( Convert_To (Etype (First_Formal (Ent)), Base), Exp)), Right_Opnd => Make_Integer_Literal (Loc, Modulus (Rtyp) - 1)))); end if; -- Common exit point for modular type case Analyze_And_Resolve (N, Typ); return; -- Signed integer cases, done using either Integer or Long_Long_Integer. -- It is not worth having routines for Short_[Short_]Integer, since for -- most machines it would not help, and it would generate more code that -- might need certification when a certified run time is required. -- In the integer cases, we have two routines, one for when overflow -- checks are required, and one when they are not required, since there -- is a real gain in omitting checks on many machines. elsif Rtyp = Base_Type (Standard_Long_Long_Integer) or else (Rtyp = Base_Type (Standard_Long_Integer) and then Esize (Standard_Long_Integer) > Esize (Standard_Integer)) or else (Rtyp = Universal_Integer) then Etyp := Standard_Long_Long_Integer; if Ovflo then Rent := RE_Exp_Long_Long_Integer; else Rent := RE_Exn_Long_Long_Integer; end if; elsif Is_Signed_Integer_Type (Rtyp) then Etyp := Standard_Integer; if Ovflo then Rent := RE_Exp_Integer; else Rent := RE_Exn_Integer; end if; -- Floating-point cases, always done using Long_Long_Float. We do not -- need separate routines for the overflow case here, since in the case -- of floating-point, we generate infinities anyway as a rule (either -- that or we automatically trap overflow), and if there is an infinity -- generated and a range check is required, the check will fail anyway. else pragma Assert (Is_Floating_Point_Type (Rtyp)); Etyp := Standard_Long_Long_Float; Rent := RE_Exn_Long_Long_Float; end if; -- Common processing for integer cases and floating-point cases. -- If we are in the right type, we can call runtime routine directly if Typ = Etyp and then Rtyp /= Universal_Integer and then Rtyp /= Universal_Real then Rewrite (N, Make_Function_Call (Loc, Name => New_Reference_To (RTE (Rent), Loc), Parameter_Associations => New_List (Base, Exp))); -- Otherwise we have to introduce conversions (conversions are also -- required in the universal cases, since the runtime routine is -- typed using one of the standard types). else Rewrite (N, Convert_To (Typ, Make_Function_Call (Loc, Name => New_Reference_To (RTE (Rent), Loc), Parameter_Associations => New_List ( Convert_To (Etyp, Base), Exp)))); end if; Analyze_And_Resolve (N, Typ); return; exception when RE_Not_Available => return; end Expand_N_Op_Expon; -------------------- -- Expand_N_Op_Ge -- -------------------- procedure Expand_N_Op_Ge (N : Node_Id) is Typ : constant Entity_Id := Etype (N); Op1 : constant Node_Id := Left_Opnd (N); Op2 : constant Node_Id := Right_Opnd (N); Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Typ1) then Expand_Array_Comparison (N); return; end if; if Is_Boolean_Type (Typ1) then Adjust_Condition (Op1); Adjust_Condition (Op2); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); end if; Rewrite_Comparison (N); -- If we still have comparison, and Vax_Float type, process it if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then Expand_Vax_Comparison (N); return; end if; Optimize_Length_Comparison (N); end Expand_N_Op_Ge; -------------------- -- Expand_N_Op_Gt -- -------------------- procedure Expand_N_Op_Gt (N : Node_Id) is Typ : constant Entity_Id := Etype (N); Op1 : constant Node_Id := Left_Opnd (N); Op2 : constant Node_Id := Right_Opnd (N); Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Typ1) then Expand_Array_Comparison (N); return; end if; if Is_Boolean_Type (Typ1) then Adjust_Condition (Op1); Adjust_Condition (Op2); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); end if; Rewrite_Comparison (N); -- If we still have comparison, and Vax_Float type, process it if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then Expand_Vax_Comparison (N); return; end if; Optimize_Length_Comparison (N); end Expand_N_Op_Gt; -------------------- -- Expand_N_Op_Le -- -------------------- procedure Expand_N_Op_Le (N : Node_Id) is Typ : constant Entity_Id := Etype (N); Op1 : constant Node_Id := Left_Opnd (N); Op2 : constant Node_Id := Right_Opnd (N); Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Typ1) then Expand_Array_Comparison (N); return; end if; if Is_Boolean_Type (Typ1) then Adjust_Condition (Op1); Adjust_Condition (Op2); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); end if; Rewrite_Comparison (N); -- If we still have comparison, and Vax_Float type, process it if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then Expand_Vax_Comparison (N); return; end if; Optimize_Length_Comparison (N); end Expand_N_Op_Le; -------------------- -- Expand_N_Op_Lt -- -------------------- procedure Expand_N_Op_Lt (N : Node_Id) is Typ : constant Entity_Id := Etype (N); Op1 : constant Node_Id := Left_Opnd (N); Op2 : constant Node_Id := Right_Opnd (N); Typ1 : constant Entity_Id := Base_Type (Etype (Op1)); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Typ1) then Expand_Array_Comparison (N); return; end if; if Is_Boolean_Type (Typ1) then Adjust_Condition (Op1); Adjust_Condition (Op2); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); end if; Rewrite_Comparison (N); -- If we still have comparison, and Vax_Float type, process it if Vax_Float (Typ1) and then Nkind (N) in N_Op_Compare then Expand_Vax_Comparison (N); return; end if; Optimize_Length_Comparison (N); end Expand_N_Op_Lt; ----------------------- -- Expand_N_Op_Minus -- ----------------------- procedure Expand_N_Op_Minus (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); begin Unary_Op_Validity_Checks (N); if not Backend_Overflow_Checks_On_Target and then Is_Signed_Integer_Type (Etype (N)) and then Do_Overflow_Check (N) then -- Software overflow checking expands -expr into (0 - expr) Rewrite (N, Make_Op_Subtract (Loc, Left_Opnd => Make_Integer_Literal (Loc, 0), Right_Opnd => Right_Opnd (N))); Analyze_And_Resolve (N, Typ); -- Vax floating-point types case elsif Vax_Float (Etype (N)) then Expand_Vax_Arith (N); end if; end Expand_N_Op_Minus; --------------------- -- Expand_N_Op_Mod -- --------------------- procedure Expand_N_Op_Mod (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Left : constant Node_Id := Left_Opnd (N); Right : constant Node_Id := Right_Opnd (N); DOC : constant Boolean := Do_Overflow_Check (N); DDC : constant Boolean := Do_Division_Check (N); LLB : Uint; Llo : Uint; Lhi : Uint; LOK : Boolean; Rlo : Uint; Rhi : Uint; ROK : Boolean; pragma Warnings (Off, Lhi); begin Binary_Op_Validity_Checks (N); Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True); Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True); -- Convert mod to rem if operands are known non-negative. We do this -- since it is quite likely that this will improve the quality of code, -- (the operation now corresponds to the hardware remainder), and it -- does not seem likely that it could be harmful. if LOK and then Llo >= 0 and then ROK and then Rlo >= 0 then Rewrite (N, Make_Op_Rem (Sloc (N), Left_Opnd => Left_Opnd (N), Right_Opnd => Right_Opnd (N))); -- Instead of reanalyzing the node we do the analysis manually. This -- avoids anomalies when the replacement is done in an instance and -- is epsilon more efficient. Set_Entity (N, Standard_Entity (S_Op_Rem)); Set_Etype (N, Typ); Set_Do_Overflow_Check (N, DOC); Set_Do_Division_Check (N, DDC); Expand_N_Op_Rem (N); Set_Analyzed (N); -- Otherwise, normal mod processing else if Is_Integer_Type (Etype (N)) then Apply_Divide_Check (N); end if; -- Apply optimization x mod 1 = 0. We don't really need that with -- gcc, but it is useful with other back ends (e.g. AAMP), and is -- certainly harmless. if Is_Integer_Type (Etype (N)) and then Compile_Time_Known_Value (Right) and then Expr_Value (Right) = Uint_1 then -- Call Remove_Side_Effects to ensure that any side effects in -- the ignored left operand (in particular function calls to -- user defined functions) are properly executed. Remove_Side_Effects (Left); Rewrite (N, Make_Integer_Literal (Loc, 0)); Analyze_And_Resolve (N, Typ); return; end if; -- Deal with annoying case of largest negative number remainder -- minus one. Gigi does not handle this case correctly, because -- it generates a divide instruction which may trap in this case. -- In fact the check is quite easy, if the right operand is -1, then -- the mod value is always 0, and we can just ignore the left operand -- completely in this case. -- The operand type may be private (e.g. in the expansion of an -- intrinsic operation) so we must use the underlying type to get the -- bounds, and convert the literals explicitly. LLB := Expr_Value (Type_Low_Bound (Base_Type (Underlying_Type (Etype (Left))))); if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) and then ((not LOK) or else (Llo = LLB)) then Rewrite (N, Make_Conditional_Expression (Loc, Expressions => New_List ( Make_Op_Eq (Loc, Left_Opnd => Duplicate_Subexpr (Right), Right_Opnd => Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))), Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, Uint_0)), Relocate_Node (N)))); Set_Analyzed (Next (Next (First (Expressions (N))))); Analyze_And_Resolve (N, Typ); end if; end if; end Expand_N_Op_Mod; -------------------------- -- Expand_N_Op_Multiply -- -------------------------- procedure Expand_N_Op_Multiply (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Lop : constant Node_Id := Left_Opnd (N); Rop : constant Node_Id := Right_Opnd (N); Lp2 : constant Boolean := Nkind (Lop) = N_Op_Expon and then Is_Power_Of_2_For_Shift (Lop); Rp2 : constant Boolean := Nkind (Rop) = N_Op_Expon and then Is_Power_Of_2_For_Shift (Rop); Ltyp : constant Entity_Id := Etype (Lop); Rtyp : constant Entity_Id := Etype (Rop); Typ : Entity_Id := Etype (N); begin Binary_Op_Validity_Checks (N); -- Special optimizations for integer types if Is_Integer_Type (Typ) then -- N * 0 = 0 for integer types if Compile_Time_Known_Value (Rop) and then Expr_Value (Rop) = Uint_0 then -- Call Remove_Side_Effects to ensure that any side effects in -- the ignored left operand (in particular function calls to -- user defined functions) are properly executed. Remove_Side_Effects (Lop); Rewrite (N, Make_Integer_Literal (Loc, Uint_0)); Analyze_And_Resolve (N, Typ); return; end if; -- Similar handling for 0 * N = 0 if Compile_Time_Known_Value (Lop) and then Expr_Value (Lop) = Uint_0 then Remove_Side_Effects (Rop); Rewrite (N, Make_Integer_Literal (Loc, Uint_0)); Analyze_And_Resolve (N, Typ); return; end if; -- N * 1 = 1 * N = N for integer types -- This optimisation is not done if we are going to -- rewrite the product 1 * 2 ** N to a shift. if Compile_Time_Known_Value (Rop) and then Expr_Value (Rop) = Uint_1 and then not Lp2 then Rewrite (N, Lop); return; elsif Compile_Time_Known_Value (Lop) and then Expr_Value (Lop) = Uint_1 and then not Rp2 then Rewrite (N, Rop); return; end if; end if; -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that -- Is_Power_Of_2_For_Shift is set means that we know that our left -- operand is an integer, as required for this to work. if Rp2 then if Lp2 then -- Convert 2 ** A * 2 ** B into 2 ** (A + B) Rewrite (N, Make_Op_Expon (Loc, Left_Opnd => Make_Integer_Literal (Loc, 2), Right_Opnd => Make_Op_Add (Loc, Left_Opnd => Right_Opnd (Lop), Right_Opnd => Right_Opnd (Rop)))); Analyze_And_Resolve (N, Typ); return; else Rewrite (N, Make_Op_Shift_Left (Loc, Left_Opnd => Lop, Right_Opnd => Convert_To (Standard_Natural, Right_Opnd (Rop)))); Analyze_And_Resolve (N, Typ); return; end if; -- Same processing for the operands the other way round elsif Lp2 then Rewrite (N, Make_Op_Shift_Left (Loc, Left_Opnd => Rop, Right_Opnd => Convert_To (Standard_Natural, Right_Opnd (Lop)))); Analyze_And_Resolve (N, Typ); return; end if; -- Do required fixup of universal fixed operation if Typ = Universal_Fixed then Fixup_Universal_Fixed_Operation (N); Typ := Etype (N); end if; -- Multiplications with fixed-point results if Is_Fixed_Point_Type (Typ) then -- No special processing if Treat_Fixed_As_Integer is set, since from -- a semantic point of view such operations are simply integer -- operations and will be treated that way. if not Treat_Fixed_As_Integer (N) then -- Case of fixed * integer => fixed if Is_Integer_Type (Rtyp) then Expand_Multiply_Fixed_By_Integer_Giving_Fixed (N); -- Case of integer * fixed => fixed elsif Is_Integer_Type (Ltyp) then Expand_Multiply_Integer_By_Fixed_Giving_Fixed (N); -- Case of fixed * fixed => fixed else Expand_Multiply_Fixed_By_Fixed_Giving_Fixed (N); end if; end if; -- Other cases of multiplication of fixed-point operands. Again we -- exclude the cases where Treat_Fixed_As_Integer flag is set. elsif (Is_Fixed_Point_Type (Ltyp) or else Is_Fixed_Point_Type (Rtyp)) and then not Treat_Fixed_As_Integer (N) then if Is_Integer_Type (Typ) then Expand_Multiply_Fixed_By_Fixed_Giving_Integer (N); else pragma Assert (Is_Floating_Point_Type (Typ)); Expand_Multiply_Fixed_By_Fixed_Giving_Float (N); end if; -- Mixed-mode operations can appear in a non-static universal context, -- in which case the integer argument must be converted explicitly. elsif Typ = Universal_Real and then Is_Integer_Type (Rtyp) then Rewrite (Rop, Convert_To (Universal_Real, Relocate_Node (Rop))); Analyze_And_Resolve (Rop, Universal_Real); elsif Typ = Universal_Real and then Is_Integer_Type (Ltyp) then Rewrite (Lop, Convert_To (Universal_Real, Relocate_Node (Lop))); Analyze_And_Resolve (Lop, Universal_Real); -- Non-fixed point cases, check software overflow checking required elsif Is_Signed_Integer_Type (Etype (N)) then Apply_Arithmetic_Overflow_Check (N); -- Deal with VAX float case elsif Vax_Float (Typ) then Expand_Vax_Arith (N); return; end if; end Expand_N_Op_Multiply; -------------------- -- Expand_N_Op_Ne -- -------------------- procedure Expand_N_Op_Ne (N : Node_Id) is Typ : constant Entity_Id := Etype (Left_Opnd (N)); begin -- Case of elementary type with standard operator if Is_Elementary_Type (Typ) and then Sloc (Entity (N)) = Standard_Location then Binary_Op_Validity_Checks (N); -- Boolean types (requiring handling of non-standard case) if Is_Boolean_Type (Typ) then Adjust_Condition (Left_Opnd (N)); Adjust_Condition (Right_Opnd (N)); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); end if; Rewrite_Comparison (N); -- If we still have comparison for Vax_Float, process it if Vax_Float (Typ) and then Nkind (N) in N_Op_Compare then Expand_Vax_Comparison (N); return; end if; -- For all cases other than elementary types, we rewrite node as the -- negation of an equality operation, and reanalyze. The equality to be -- used is defined in the same scope and has the same signature. This -- signature must be set explicitly since in an instance it may not have -- the same visibility as in the generic unit. This avoids duplicating -- or factoring the complex code for record/array equality tests etc. else declare Loc : constant Source_Ptr := Sloc (N); Neg : Node_Id; Ne : constant Entity_Id := Entity (N); begin Binary_Op_Validity_Checks (N); Neg := Make_Op_Not (Loc, Right_Opnd => Make_Op_Eq (Loc, Left_Opnd => Left_Opnd (N), Right_Opnd => Right_Opnd (N))); Set_Paren_Count (Right_Opnd (Neg), 1); if Scope (Ne) /= Standard_Standard then Set_Entity (Right_Opnd (Neg), Corresponding_Equality (Ne)); end if; -- For navigation purposes, we want to treat the inequality as an -- implicit reference to the corresponding equality. Preserve the -- Comes_From_ source flag to generate proper Xref entries. Preserve_Comes_From_Source (Neg, N); Preserve_Comes_From_Source (Right_Opnd (Neg), N); Rewrite (N, Neg); Analyze_And_Resolve (N, Standard_Boolean); end; end if; Optimize_Length_Comparison (N); end Expand_N_Op_Ne; --------------------- -- Expand_N_Op_Not -- --------------------- -- If the argument is other than a Boolean array type, there is no special -- expansion required, except for VMS operations on signed integers. -- For the packed case, we call the special routine in Exp_Pakd, except -- that if the component size is greater than one, we use the standard -- routine generating a gruesome loop (it is so peculiar to have packed -- arrays with non-standard Boolean representations anyway, so it does not -- matter that we do not handle this case efficiently). -- For the unpacked case (and for the special packed case where we have non -- standard Booleans, as discussed above), we generate and insert into the -- tree the following function definition: -- function Nnnn (A : arr) is -- B : arr; -- begin -- for J in a'range loop -- B (J) := not A (J); -- end loop; -- return B; -- end Nnnn; -- Here arr is the actual subtype of the parameter (and hence always -- constrained). Then we replace the not with a call to this function. procedure Expand_N_Op_Not (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Opnd : Node_Id; Arr : Entity_Id; A : Entity_Id; B : Entity_Id; J : Entity_Id; A_J : Node_Id; B_J : Node_Id; Func_Name : Entity_Id; Loop_Statement : Node_Id; begin Unary_Op_Validity_Checks (N); -- For boolean operand, deal with non-standard booleans if Is_Boolean_Type (Typ) then Adjust_Condition (Right_Opnd (N)); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); return; end if; -- For the VMS "not" on signed integer types, use conversion to and from -- a predefined modular type. if Is_VMS_Operator (Entity (N)) then declare Rtyp : Entity_Id; Utyp : Entity_Id; begin -- If this is a derived type, retrieve original VMS type so that -- the proper sized type is used for intermediate values. if Is_Derived_Type (Typ) then Rtyp := First_Subtype (Etype (Typ)); else Rtyp := Typ; end if; -- The proper unsigned type must have a size compatible with the -- operand, to prevent misalignment. if RM_Size (Rtyp) <= 8 then Utyp := RTE (RE_Unsigned_8); elsif RM_Size (Rtyp) <= 16 then Utyp := RTE (RE_Unsigned_16); elsif RM_Size (Rtyp) = RM_Size (Standard_Unsigned) then Utyp := RTE (RE_Unsigned_32); else Utyp := RTE (RE_Long_Long_Unsigned); end if; Rewrite (N, Unchecked_Convert_To (Typ, Make_Op_Not (Loc, Unchecked_Convert_To (Utyp, Right_Opnd (N))))); Analyze_And_Resolve (N, Typ); return; end; end if; -- Only array types need any other processing if not Is_Array_Type (Typ) then return; end if; -- Case of array operand. If bit packed with a component size of 1, -- handle it in Exp_Pakd if the operand is known to be aligned. if Is_Bit_Packed_Array (Typ) and then Component_Size (Typ) = 1 and then not Is_Possibly_Unaligned_Object (Right_Opnd (N)) then Expand_Packed_Not (N); return; end if; -- Case of array operand which is not bit-packed. If the context is -- a safe assignment, call in-place operation, If context is a larger -- boolean expression in the context of a safe assignment, expansion is -- done by enclosing operation. Opnd := Relocate_Node (Right_Opnd (N)); Convert_To_Actual_Subtype (Opnd); Arr := Etype (Opnd); Ensure_Defined (Arr, N); Silly_Boolean_Array_Not_Test (N, Arr); if Nkind (Parent (N)) = N_Assignment_Statement then if Safe_In_Place_Array_Op (Name (Parent (N)), N, Empty) then Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty); return; -- Special case the negation of a binary operation elsif Nkind_In (Opnd, N_Op_And, N_Op_Or, N_Op_Xor) and then Safe_In_Place_Array_Op (Name (Parent (N)), Left_Opnd (Opnd), Right_Opnd (Opnd)) then Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty); return; end if; elsif Nkind (Parent (N)) in N_Binary_Op and then Nkind (Parent (Parent (N))) = N_Assignment_Statement then declare Op1 : constant Node_Id := Left_Opnd (Parent (N)); Op2 : constant Node_Id := Right_Opnd (Parent (N)); Lhs : constant Node_Id := Name (Parent (Parent (N))); begin if Safe_In_Place_Array_Op (Lhs, Op1, Op2) then -- (not A) op (not B) can be reduced to a single call if N = Op1 and then Nkind (Op2) = N_Op_Not then return; elsif N = Op2 and then Nkind (Op1) = N_Op_Not then return; -- A xor (not B) can also be special-cased elsif N = Op2 and then Nkind (Parent (N)) = N_Op_Xor then return; end if; end if; end; end if; A := Make_Defining_Identifier (Loc, Name_uA); B := Make_Defining_Identifier (Loc, Name_uB); J := Make_Defining_Identifier (Loc, Name_uJ); A_J := Make_Indexed_Component (Loc, Prefix => New_Reference_To (A, Loc), Expressions => New_List (New_Reference_To (J, Loc))); B_J := Make_Indexed_Component (Loc, Prefix => New_Reference_To (B, Loc), Expressions => New_List (New_Reference_To (J, Loc))); Loop_Statement := Make_Implicit_Loop_Statement (N, Identifier => Empty, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => J, Discrete_Subtype_Definition => Make_Attribute_Reference (Loc, Prefix => Make_Identifier (Loc, Chars (A)), Attribute_Name => Name_Range))), Statements => New_List ( Make_Assignment_Statement (Loc, Name => B_J, Expression => Make_Op_Not (Loc, A_J)))); Func_Name := Make_Temporary (Loc, 'N'); Set_Is_Inlined (Func_Name); Insert_Action (N, Make_Subprogram_Body (Loc, Specification => Make_Function_Specification (Loc, Defining_Unit_Name => Func_Name, Parameter_Specifications => New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => A, Parameter_Type => New_Reference_To (Typ, Loc))), Result_Definition => New_Reference_To (Typ, Loc)), Declarations => New_List ( Make_Object_Declaration (Loc, Defining_Identifier => B, Object_Definition => New_Reference_To (Arr, Loc))), Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Loop_Statement, Make_Simple_Return_Statement (Loc, Expression => Make_Identifier (Loc, Chars (B))))))); Rewrite (N, Make_Function_Call (Loc, Name => New_Reference_To (Func_Name, Loc), Parameter_Associations => New_List (Opnd))); Analyze_And_Resolve (N, Typ); end Expand_N_Op_Not; -------------------- -- Expand_N_Op_Or -- -------------------- procedure Expand_N_Op_Or (N : Node_Id) is Typ : constant Entity_Id := Etype (N); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Etype (N)) then Expand_Boolean_Operator (N); elsif Is_Boolean_Type (Etype (N)) then Adjust_Condition (Left_Opnd (N)); Adjust_Condition (Right_Opnd (N)); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); elsif Is_Intrinsic_Subprogram (Entity (N)) then Expand_Intrinsic_Call (N, Entity (N)); end if; end Expand_N_Op_Or; ---------------------- -- Expand_N_Op_Plus -- ---------------------- procedure Expand_N_Op_Plus (N : Node_Id) is begin Unary_Op_Validity_Checks (N); end Expand_N_Op_Plus; --------------------- -- Expand_N_Op_Rem -- --------------------- procedure Expand_N_Op_Rem (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Left : constant Node_Id := Left_Opnd (N); Right : constant Node_Id := Right_Opnd (N); Lo : Uint; Hi : Uint; OK : Boolean; Lneg : Boolean; Rneg : Boolean; -- Set if corresponding operand can be negative pragma Unreferenced (Hi); begin Binary_Op_Validity_Checks (N); if Is_Integer_Type (Etype (N)) then Apply_Divide_Check (N); end if; -- Apply optimization x rem 1 = 0. We don't really need that with gcc, -- but it is useful with other back ends (e.g. AAMP), and is certainly -- harmless. if Is_Integer_Type (Etype (N)) and then Compile_Time_Known_Value (Right) and then Expr_Value (Right) = Uint_1 then -- Call Remove_Side_Effects to ensure that any side effects in the -- ignored left operand (in particular function calls to user defined -- functions) are properly executed. Remove_Side_Effects (Left); Rewrite (N, Make_Integer_Literal (Loc, 0)); Analyze_And_Resolve (N, Typ); return; end if; -- Deal with annoying case of largest negative number remainder minus -- one. Gigi does not handle this case correctly, because it generates -- a divide instruction which may trap in this case. -- In fact the check is quite easy, if the right operand is -1, then -- the remainder is always 0, and we can just ignore the left operand -- completely in this case. Determine_Range (Right, OK, Lo, Hi, Assume_Valid => True); Lneg := (not OK) or else Lo < 0; Determine_Range (Left, OK, Lo, Hi, Assume_Valid => True); Rneg := (not OK) or else Lo < 0; -- We won't mess with trying to find out if the left operand can really -- be the largest negative number (that's a pain in the case of private -- types and this is really marginal). We will just assume that we need -- the test if the left operand can be negative at all. if Lneg and Rneg then Rewrite (N, Make_Conditional_Expression (Loc, Expressions => New_List ( Make_Op_Eq (Loc, Left_Opnd => Duplicate_Subexpr (Right), Right_Opnd => Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, -1))), Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, Uint_0)), Relocate_Node (N)))); Set_Analyzed (Next (Next (First (Expressions (N))))); Analyze_And_Resolve (N, Typ); end if; end Expand_N_Op_Rem; ----------------------------- -- Expand_N_Op_Rotate_Left -- ----------------------------- procedure Expand_N_Op_Rotate_Left (N : Node_Id) is begin Binary_Op_Validity_Checks (N); end Expand_N_Op_Rotate_Left; ------------------------------ -- Expand_N_Op_Rotate_Right -- ------------------------------ procedure Expand_N_Op_Rotate_Right (N : Node_Id) is begin Binary_Op_Validity_Checks (N); end Expand_N_Op_Rotate_Right; ---------------------------- -- Expand_N_Op_Shift_Left -- ---------------------------- procedure Expand_N_Op_Shift_Left (N : Node_Id) is begin Binary_Op_Validity_Checks (N); end Expand_N_Op_Shift_Left; ----------------------------- -- Expand_N_Op_Shift_Right -- ----------------------------- procedure Expand_N_Op_Shift_Right (N : Node_Id) is begin Binary_Op_Validity_Checks (N); end Expand_N_Op_Shift_Right; ---------------------------------------- -- Expand_N_Op_Shift_Right_Arithmetic -- ---------------------------------------- procedure Expand_N_Op_Shift_Right_Arithmetic (N : Node_Id) is begin Binary_Op_Validity_Checks (N); end Expand_N_Op_Shift_Right_Arithmetic; -------------------------- -- Expand_N_Op_Subtract -- -------------------------- procedure Expand_N_Op_Subtract (N : Node_Id) is Typ : constant Entity_Id := Etype (N); begin Binary_Op_Validity_Checks (N); -- N - 0 = N for integer types if Is_Integer_Type (Typ) and then Compile_Time_Known_Value (Right_Opnd (N)) and then Expr_Value (Right_Opnd (N)) = 0 then Rewrite (N, Left_Opnd (N)); return; end if; -- Arithmetic overflow checks for signed integer/fixed point types if Is_Signed_Integer_Type (Typ) or else Is_Fixed_Point_Type (Typ) then Apply_Arithmetic_Overflow_Check (N); -- VAX floating-point types case elsif Vax_Float (Typ) then Expand_Vax_Arith (N); end if; end Expand_N_Op_Subtract; --------------------- -- Expand_N_Op_Xor -- --------------------- procedure Expand_N_Op_Xor (N : Node_Id) is Typ : constant Entity_Id := Etype (N); begin Binary_Op_Validity_Checks (N); if Is_Array_Type (Etype (N)) then Expand_Boolean_Operator (N); elsif Is_Boolean_Type (Etype (N)) then Adjust_Condition (Left_Opnd (N)); Adjust_Condition (Right_Opnd (N)); Set_Etype (N, Standard_Boolean); Adjust_Result_Type (N, Typ); elsif Is_Intrinsic_Subprogram (Entity (N)) then Expand_Intrinsic_Call (N, Entity (N)); end if; end Expand_N_Op_Xor; ---------------------- -- Expand_N_Or_Else -- ---------------------- procedure Expand_N_Or_Else (N : Node_Id) renames Expand_Short_Circuit_Operator; ----------------------------------- -- Expand_N_Qualified_Expression -- ----------------------------------- procedure Expand_N_Qualified_Expression (N : Node_Id) is Operand : constant Node_Id := Expression (N); Target_Type : constant Entity_Id := Entity (Subtype_Mark (N)); begin -- Do validity check if validity checking operands if Validity_Checks_On and then Validity_Check_Operands then Ensure_Valid (Operand); end if; -- Apply possible constraint check Apply_Constraint_Check (Operand, Target_Type, No_Sliding => True); if Do_Range_Check (Operand) then Set_Do_Range_Check (Operand, False); Generate_Range_Check (Operand, Target_Type, CE_Range_Check_Failed); end if; end Expand_N_Qualified_Expression; ------------------------------------ -- Expand_N_Quantified_Expression -- ------------------------------------ -- We expand: -- for all X in range => Cond -- into: -- T := True; -- for X in range loop -- if not Cond then -- T := False; -- exit; -- end if; -- end loop; -- Conversely, an existentially quantified expression: -- for some X in range => Cond -- becomes: -- T := False; -- for X in range loop -- if Cond then -- T := True; -- exit; -- end if; -- end loop; -- In both cases, the iteration may be over a container in which case it is -- given by an iterator specification, not a loop parameter specification. procedure Expand_N_Quantified_Expression (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Is_Universal : constant Boolean := All_Present (N); Actions : constant List_Id := New_List; Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); Cond : Node_Id; Decl : Node_Id; I_Scheme : Node_Id; Test : Node_Id; begin Decl := Make_Object_Declaration (Loc, Defining_Identifier => Tnn, Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc), Expression => New_Occurrence_Of (Boolean_Literals (Is_Universal), Loc)); Append_To (Actions, Decl); Cond := Relocate_Node (Condition (N)); -- Reset flag analyzed in the condition to force its analysis. Required -- since the previous analysis was done with expansion disabled (see -- Resolve_Quantified_Expression) and hence checks were not inserted -- and record comparisons have not been expanded. Reset_Analyzed_Flags (Cond); if Is_Universal then Cond := Make_Op_Not (Loc, Cond); end if; Test := Make_Implicit_If_Statement (N, Condition => Cond, Then_Statements => New_List ( Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Tnn, Loc), Expression => New_Occurrence_Of (Boolean_Literals (not Is_Universal), Loc)), Make_Exit_Statement (Loc))); if Present (Loop_Parameter_Specification (N)) then I_Scheme := Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Loop_Parameter_Specification (N)); else I_Scheme := Make_Iteration_Scheme (Loc, Iterator_Specification => Iterator_Specification (N)); end if; Append_To (Actions, Make_Loop_Statement (Loc, Iteration_Scheme => I_Scheme, Statements => New_List (Test), End_Label => Empty)); Rewrite (N, Make_Expression_With_Actions (Loc, Expression => New_Occurrence_Of (Tnn, Loc), Actions => Actions)); Analyze_And_Resolve (N, Standard_Boolean); end Expand_N_Quantified_Expression; --------------------------------- -- Expand_N_Selected_Component -- --------------------------------- procedure Expand_N_Selected_Component (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Par : constant Node_Id := Parent (N); P : constant Node_Id := Prefix (N); Ptyp : Entity_Id := Underlying_Type (Etype (P)); Disc : Entity_Id; New_N : Node_Id; Dcon : Elmt_Id; Dval : Node_Id; function In_Left_Hand_Side (Comp : Node_Id) return Boolean; -- Gigi needs a temporary for prefixes that depend on a discriminant, -- unless the context of an assignment can provide size information. -- Don't we have a general routine that does this??? function Is_Subtype_Declaration return Boolean; -- The replacement of a discriminant reference by its value is required -- if this is part of the initialization of an temporary generated by a -- change of representation. This shows up as the construction of a -- discriminant constraint for a subtype declared at the same point as -- the entity in the prefix of the selected component. We recognize this -- case when the context of the reference is: -- subtype ST is T(Obj.D); -- where the entity for Obj comes from source, and ST has the same sloc. ----------------------- -- In_Left_Hand_Side -- ----------------------- function In_Left_Hand_Side (Comp : Node_Id) return Boolean is begin return (Nkind (Parent (Comp)) = N_Assignment_Statement and then Comp = Name (Parent (Comp))) or else (Present (Parent (Comp)) and then Nkind (Parent (Comp)) in N_Subexpr and then In_Left_Hand_Side (Parent (Comp))); end In_Left_Hand_Side; ----------------------------- -- Is_Subtype_Declaration -- ----------------------------- function Is_Subtype_Declaration return Boolean is Par : constant Node_Id := Parent (N); begin return Nkind (Par) = N_Index_Or_Discriminant_Constraint and then Nkind (Parent (Parent (Par))) = N_Subtype_Declaration and then Comes_From_Source (Entity (Prefix (N))) and then Sloc (Par) = Sloc (Entity (Prefix (N))); end Is_Subtype_Declaration; -- Start of processing for Expand_N_Selected_Component begin -- Insert explicit dereference if required if Is_Access_Type (Ptyp) then -- First set prefix type to proper access type, in case it currently -- has a private (non-access) view of this type. Set_Etype (P, Ptyp); Insert_Explicit_Dereference (P); Analyze_And_Resolve (P, Designated_Type (Ptyp)); if Ekind (Etype (P)) = E_Private_Subtype and then Is_For_Access_Subtype (Etype (P)) then Set_Etype (P, Base_Type (Etype (P))); end if; Ptyp := Etype (P); end if; -- Deal with discriminant check required if Do_Discriminant_Check (N) then -- Present the discriminant checking function to the backend, so that -- it can inline the call to the function. Add_Inlined_Body (Discriminant_Checking_Func (Original_Record_Component (Entity (Selector_Name (N))))); -- Now reset the flag and generate the call Set_Do_Discriminant_Check (N, False); Generate_Discriminant_Check (N); end if; -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place -- function, then additional actuals must be passed. if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function_Call (P) then Make_Build_In_Place_Call_In_Anonymous_Context (P); end if; -- Gigi cannot handle unchecked conversions that are the prefix of a -- selected component with discriminants. This must be checked during -- expansion, because during analysis the type of the selector is not -- known at the point the prefix is analyzed. If the conversion is the -- target of an assignment, then we cannot force the evaluation. if Nkind (Prefix (N)) = N_Unchecked_Type_Conversion and then Has_Discriminants (Etype (N)) and then not In_Left_Hand_Side (N) then Force_Evaluation (Prefix (N)); end if; -- Remaining processing applies only if selector is a discriminant if Ekind (Entity (Selector_Name (N))) = E_Discriminant then -- If the selector is a discriminant of a constrained record type, -- we may be able to rewrite the expression with the actual value -- of the discriminant, a useful optimization in some cases. if Is_Record_Type (Ptyp) and then Has_Discriminants (Ptyp) and then Is_Constrained (Ptyp) then -- Do this optimization for discrete types only, and not for -- access types (access discriminants get us into trouble!) if not Is_Discrete_Type (Etype (N)) then null; -- Don't do this on the left hand of an assignment statement. -- Normally one would think that references like this would not -- occur, but they do in generated code, and mean that we really -- do want to assign the discriminant! elsif Nkind (Par) = N_Assignment_Statement and then Name (Par) = N then null; -- Don't do this optimization for the prefix of an attribute or -- the name of an object renaming declaration since these are -- contexts where we do not want the value anyway. elsif (Nkind (Par) = N_Attribute_Reference and then Prefix (Par) = N) or else Is_Renamed_Object (N) then null; -- Don't do this optimization if we are within the code for a -- discriminant check, since the whole point of such a check may -- be to verify the condition on which the code below depends! elsif Is_In_Discriminant_Check (N) then null; -- Green light to see if we can do the optimization. There is -- still one condition that inhibits the optimization below but -- now is the time to check the particular discriminant. else -- Loop through discriminants to find the matching discriminant -- constraint to see if we can copy it. Disc := First_Discriminant (Ptyp); Dcon := First_Elmt (Discriminant_Constraint (Ptyp)); Discr_Loop : while Present (Dcon) loop Dval := Node (Dcon); -- Check if this is the matching discriminant and if the -- discriminant value is simple enough to make sense to -- copy. We don't want to copy complex expressions, and -- indeed to do so can cause trouble (before we put in -- this guard, a discriminant expression containing an -- AND THEN was copied, causing problems for coverage -- analysis tools). -- However, if the reference is part of the initialization -- code generated for an object declaration, we must use -- the discriminant value from the subtype constraint, -- because the selected component may be a reference to the -- object being initialized, whose discriminant is not yet -- set. This only happens in complex cases involving changes -- or representation. if Disc = Entity (Selector_Name (N)) and then (Is_Entity_Name (Dval) or else Compile_Time_Known_Value (Dval) or else Is_Subtype_Declaration) then -- Here we have the matching discriminant. Check for -- the case of a discriminant of a component that is -- constrained by an outer discriminant, which cannot -- be optimized away. if Denotes_Discriminant (Dval, Check_Concurrent => True) then exit Discr_Loop; elsif Nkind (Original_Node (Dval)) = N_Selected_Component and then Denotes_Discriminant (Selector_Name (Original_Node (Dval)), True) then exit Discr_Loop; -- Do not retrieve value if constraint is not static. It -- is generally not useful, and the constraint may be a -- rewritten outer discriminant in which case it is in -- fact incorrect. elsif Is_Entity_Name (Dval) and then Nkind (Parent (Entity (Dval))) = N_Object_Declaration and then Present (Expression (Parent (Entity (Dval)))) and then not Is_Static_Expression (Expression (Parent (Entity (Dval)))) then exit Discr_Loop; -- In the context of a case statement, the expression may -- have the base type of the discriminant, and we need to -- preserve the constraint to avoid spurious errors on -- missing cases. elsif Nkind (Parent (N)) = N_Case_Statement and then Etype (Dval) /= Etype (Disc) then Rewrite (N, Make_Qualified_Expression (Loc, Subtype_Mark => New_Occurrence_Of (Etype (Disc), Loc), Expression => New_Copy_Tree (Dval))); Analyze_And_Resolve (N, Etype (Disc)); -- In case that comes out as a static expression, -- reset it (a selected component is never static). Set_Is_Static_Expression (N, False); return; -- Otherwise we can just copy the constraint, but the -- result is certainly not static! In some cases the -- discriminant constraint has been analyzed in the -- context of the original subtype indication, but for -- itypes the constraint might not have been analyzed -- yet, and this must be done now. else Rewrite (N, New_Copy_Tree (Dval)); Analyze_And_Resolve (N); Set_Is_Static_Expression (N, False); return; end if; end if; Next_Elmt (Dcon); Next_Discriminant (Disc); end loop Discr_Loop; -- Note: the above loop should always find a matching -- discriminant, but if it does not, we just missed an -- optimization due to some glitch (perhaps a previous -- error), so ignore. end if; end if; -- The only remaining processing is in the case of a discriminant of -- a concurrent object, where we rewrite the prefix to denote the -- corresponding record type. If the type is derived and has renamed -- discriminants, use corresponding discriminant, which is the one -- that appears in the corresponding record. if not Is_Concurrent_Type (Ptyp) then return; end if; Disc := Entity (Selector_Name (N)); if Is_Derived_Type (Ptyp) and then Present (Corresponding_Discriminant (Disc)) then Disc := Corresponding_Discriminant (Disc); end if; New_N := Make_Selected_Component (Loc, Prefix => Unchecked_Convert_To (Corresponding_Record_Type (Ptyp), New_Copy_Tree (P)), Selector_Name => Make_Identifier (Loc, Chars (Disc))); Rewrite (N, New_N); Analyze (N); end if; -- Set Atomic_Sync_Required if necessary for atomic component if Nkind (N) = N_Selected_Component then declare E : constant Entity_Id := Entity (Selector_Name (N)); Set : Boolean; begin -- If component is atomic, but type is not, setting depends on -- disable/enable state for the component. if Is_Atomic (E) and then not Is_Atomic (Etype (E)) then Set := not Atomic_Synchronization_Disabled (E); -- If component is not atomic, but its type is atomic, setting -- depends on disable/enable state for the type. elsif not Is_Atomic (E) and then Is_Atomic (Etype (E)) then Set := not Atomic_Synchronization_Disabled (Etype (E)); -- If both component and type are atomic, we disable if either -- component or its type have sync disabled. elsif Is_Atomic (E) and then Is_Atomic (Etype (E)) then Set := (not Atomic_Synchronization_Disabled (E)) and then (not Atomic_Synchronization_Disabled (Etype (E))); else Set := False; end if; -- Set flag if required if Set then Activate_Atomic_Synchronization (N); end if; end; end if; end Expand_N_Selected_Component; -------------------- -- Expand_N_Slice -- -------------------- procedure Expand_N_Slice (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Pfx : constant Node_Id := Prefix (N); Ptp : Entity_Id := Etype (Pfx); function Is_Procedure_Actual (N : Node_Id) return Boolean; -- Check whether the argument is an actual for a procedure call, in -- which case the expansion of a bit-packed slice is deferred until the -- call itself is expanded. The reason this is required is that we might -- have an IN OUT or OUT parameter, and the copy out is essential, and -- that copy out would be missed if we created a temporary here in -- Expand_N_Slice. Note that we don't bother to test specifically for an -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it -- is harmless to defer expansion in the IN case, since the call -- processing will still generate the appropriate copy in operation, -- which will take care of the slice. procedure Make_Temporary_For_Slice; -- Create a named variable for the value of the slice, in cases where -- the back-end cannot handle it properly, e.g. when packed types or -- unaligned slices are involved. ------------------------- -- Is_Procedure_Actual -- ------------------------- function Is_Procedure_Actual (N : Node_Id) return Boolean is Par : Node_Id := Parent (N); begin loop -- If our parent is a procedure call we can return if Nkind (Par) = N_Procedure_Call_Statement then return True; -- If our parent is a type conversion, keep climbing the tree, -- since a type conversion can be a procedure actual. Also keep -- climbing if parameter association or a qualified expression, -- since these are additional cases that do can appear on -- procedure actuals. elsif Nkind_In (Par, N_Type_Conversion, N_Parameter_Association, N_Qualified_Expression) then Par := Parent (Par); -- Any other case is not what we are looking for else return False; end if; end loop; end Is_Procedure_Actual; ------------------------------ -- Make_Temporary_For_Slice -- ------------------------------ procedure Make_Temporary_For_Slice is Decl : Node_Id; Ent : constant Entity_Id := Make_Temporary (Loc, 'T', N); begin Decl := Make_Object_Declaration (Loc, Defining_Identifier => Ent, Object_Definition => New_Occurrence_Of (Typ, Loc)); Set_No_Initialization (Decl); Insert_Actions (N, New_List ( Decl, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Ent, Loc), Expression => Relocate_Node (N)))); Rewrite (N, New_Occurrence_Of (Ent, Loc)); Analyze_And_Resolve (N, Typ); end Make_Temporary_For_Slice; -- Start of processing for Expand_N_Slice begin -- Special handling for access types if Is_Access_Type (Ptp) then Ptp := Designated_Type (Ptp); Rewrite (Pfx, Make_Explicit_Dereference (Sloc (N), Prefix => Relocate_Node (Pfx))); Analyze_And_Resolve (Pfx, Ptp); end if; -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place -- function, then additional actuals must be passed. if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function_Call (Pfx) then Make_Build_In_Place_Call_In_Anonymous_Context (Pfx); end if; -- The remaining case to be handled is packed slices. We can leave -- packed slices as they are in the following situations: -- 1. Right or left side of an assignment (we can handle this -- situation correctly in the assignment statement expansion). -- 2. Prefix of indexed component (the slide is optimized away in this -- case, see the start of Expand_N_Slice.) -- 3. Object renaming declaration, since we want the name of the -- slice, not the value. -- 4. Argument to procedure call, since copy-in/copy-out handling may -- be required, and this is handled in the expansion of call -- itself. -- 5. Prefix of an address attribute (this is an error which is caught -- elsewhere, and the expansion would interfere with generating the -- error message). if not Is_Packed (Typ) then -- Apply transformation for actuals of a function call, where -- Expand_Actuals is not used. if Nkind (Parent (N)) = N_Function_Call and then Is_Possibly_Unaligned_Slice (N) then Make_Temporary_For_Slice; end if; elsif Nkind (Parent (N)) = N_Assignment_Statement or else (Nkind (Parent (Parent (N))) = N_Assignment_Statement and then Parent (N) = Name (Parent (Parent (N)))) then return; elsif Nkind (Parent (N)) = N_Indexed_Component or else Is_Renamed_Object (N) or else Is_Procedure_Actual (N) then return; elsif Nkind (Parent (N)) = N_Attribute_Reference and then Attribute_Name (Parent (N)) = Name_Address then return; else Make_Temporary_For_Slice; end if; end Expand_N_Slice; ------------------------------ -- Expand_N_Type_Conversion -- ------------------------------ procedure Expand_N_Type_Conversion (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Operand : constant Node_Id := Expression (N); Target_Type : constant Entity_Id := Etype (N); Operand_Type : Entity_Id := Etype (Operand); procedure Handle_Changed_Representation; -- This is called in the case of record and array type conversions to -- see if there is a change of representation to be handled. Change of -- representation is actually handled at the assignment statement level, -- and what this procedure does is rewrite node N conversion as an -- assignment to temporary. If there is no change of representation, -- then the conversion node is unchanged. procedure Raise_Accessibility_Error; -- Called when we know that an accessibility check will fail. Rewrites -- node N to an appropriate raise statement and outputs warning msgs. -- The Etype of the raise node is set to Target_Type. procedure Real_Range_Check; -- Handles generation of range check for real target value function Has_Extra_Accessibility (Id : Entity_Id) return Boolean; -- True iff Present (Effective_Extra_Accessibility (Id)) successfully -- evaluates to True. ----------------------------------- -- Handle_Changed_Representation -- ----------------------------------- procedure Handle_Changed_Representation is Temp : Entity_Id; Decl : Node_Id; Odef : Node_Id; Disc : Node_Id; N_Ix : Node_Id; Cons : List_Id; begin -- Nothing else to do if no change of representation if Same_Representation (Operand_Type, Target_Type) then return; -- The real change of representation work is done by the assignment -- statement processing. So if this type conversion is appearing as -- the expression of an assignment statement, nothing needs to be -- done to the conversion. elsif Nkind (Parent (N)) = N_Assignment_Statement then return; -- Otherwise we need to generate a temporary variable, and do the -- change of representation assignment into that temporary variable. -- The conversion is then replaced by a reference to this variable. else Cons := No_List; -- If type is unconstrained we have to add a constraint, copied -- from the actual value of the left hand side. if not Is_Constrained (Target_Type) then if Has_Discriminants (Operand_Type) then Disc := First_Discriminant (Operand_Type); if Disc /= First_Stored_Discriminant (Operand_Type) then Disc := First_Stored_Discriminant (Operand_Type); end if; Cons := New_List; while Present (Disc) loop Append_To (Cons, Make_Selected_Component (Loc, Prefix => Duplicate_Subexpr_Move_Checks (Operand), Selector_Name => Make_Identifier (Loc, Chars (Disc)))); Next_Discriminant (Disc); end loop; elsif Is_Array_Type (Operand_Type) then N_Ix := First_Index (Target_Type); Cons := New_List; for J in 1 .. Number_Dimensions (Operand_Type) loop -- We convert the bounds explicitly. We use an unchecked -- conversion because bounds checks are done elsewhere. Append_To (Cons, Make_Range (Loc, Low_Bound => Unchecked_Convert_To (Etype (N_Ix), Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (Operand, Name_Req => True), Attribute_Name => Name_First, Expressions => New_List ( Make_Integer_Literal (Loc, J)))), High_Bound => Unchecked_Convert_To (Etype (N_Ix), Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (Operand, Name_Req => True), Attribute_Name => Name_Last, Expressions => New_List ( Make_Integer_Literal (Loc, J)))))); Next_Index (N_Ix); end loop; end if; end if; Odef := New_Occurrence_Of (Target_Type, Loc); if Present (Cons) then Odef := Make_Subtype_Indication (Loc, Subtype_Mark => Odef, Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => Cons)); end if; Temp := Make_Temporary (Loc, 'C'); Decl := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Object_Definition => Odef); Set_No_Initialization (Decl, True); -- Insert required actions. It is essential to suppress checks -- since we have suppressed default initialization, which means -- that the variable we create may have no discriminants. Insert_Actions (N, New_List ( Decl, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Temp, Loc), Expression => Relocate_Node (N))), Suppress => All_Checks); Rewrite (N, New_Occurrence_Of (Temp, Loc)); return; end if; end Handle_Changed_Representation; ------------------------------- -- Raise_Accessibility_Error -- ------------------------------- procedure Raise_Accessibility_Error is begin Rewrite (N, Make_Raise_Program_Error (Sloc (N), Reason => PE_Accessibility_Check_Failed)); Set_Etype (N, Target_Type); Error_Msg_N ("?accessibility check failure", N); Error_Msg_NE ("\?& will be raised at run time", N, Standard_Program_Error); end Raise_Accessibility_Error; ---------------------- -- Real_Range_Check -- ---------------------- -- Case of conversions to floating-point or fixed-point. If range checks -- are enabled and the target type has a range constraint, we convert: -- typ (x) -- to -- Tnn : typ'Base := typ'Base (x); -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last] -- Tnn -- This is necessary when there is a conversion of integer to float or -- to fixed-point to ensure that the correct checks are made. It is not -- necessary for float to float where it is enough to simply set the -- Do_Range_Check flag. procedure Real_Range_Check is Btyp : constant Entity_Id := Base_Type (Target_Type); Lo : constant Node_Id := Type_Low_Bound (Target_Type); Hi : constant Node_Id := Type_High_Bound (Target_Type); Xtyp : constant Entity_Id := Etype (Operand); Conv : Node_Id; Tnn : Entity_Id; begin -- Nothing to do if conversion was rewritten if Nkind (N) /= N_Type_Conversion then return; end if; -- Nothing to do if range checks suppressed, or target has the same -- range as the base type (or is the base type). if Range_Checks_Suppressed (Target_Type) or else (Lo = Type_Low_Bound (Btyp) and then Hi = Type_High_Bound (Btyp)) then return; end if; -- Nothing to do if expression is an entity on which checks have been -- suppressed. if Is_Entity_Name (Operand) and then Range_Checks_Suppressed (Entity (Operand)) then return; end if; -- Nothing to do if bounds are all static and we can tell that the -- expression is within the bounds of the target. Note that if the -- operand is of an unconstrained floating-point type, then we do -- not trust it to be in range (might be infinite) declare S_Lo : constant Node_Id := Type_Low_Bound (Xtyp); S_Hi : constant Node_Id := Type_High_Bound (Xtyp); begin if (not Is_Floating_Point_Type (Xtyp) or else Is_Constrained (Xtyp)) and then Compile_Time_Known_Value (S_Lo) and then Compile_Time_Known_Value (S_Hi) and then Compile_Time_Known_Value (Hi) and then Compile_Time_Known_Value (Lo) then declare D_Lov : constant Ureal := Expr_Value_R (Lo); D_Hiv : constant Ureal := Expr_Value_R (Hi); S_Lov : Ureal; S_Hiv : Ureal; begin if Is_Real_Type (Xtyp) then S_Lov := Expr_Value_R (S_Lo); S_Hiv := Expr_Value_R (S_Hi); else S_Lov := UR_From_Uint (Expr_Value (S_Lo)); S_Hiv := UR_From_Uint (Expr_Value (S_Hi)); end if; if D_Hiv > D_Lov and then S_Lov >= D_Lov and then S_Hiv <= D_Hiv then Set_Do_Range_Check (Operand, False); return; end if; end; end if; end; -- For float to float conversions, we are done if Is_Floating_Point_Type (Xtyp) and then Is_Floating_Point_Type (Btyp) then return; end if; -- Otherwise rewrite the conversion as described above Conv := Relocate_Node (N); Rewrite (Subtype_Mark (Conv), New_Occurrence_Of (Btyp, Loc)); Set_Etype (Conv, Btyp); -- Enable overflow except for case of integer to float conversions, -- where it is never required, since we can never have overflow in -- this case. if not Is_Integer_Type (Etype (Operand)) then Enable_Overflow_Check (Conv); end if; Tnn := Make_Temporary (Loc, 'T', Conv); Insert_Actions (N, New_List ( Make_Object_Declaration (Loc, Defining_Identifier => Tnn, Object_Definition => New_Occurrence_Of (Btyp, Loc), Constant_Present => True, Expression => Conv), Make_Raise_Constraint_Error (Loc, Condition => Make_Or_Else (Loc, Left_Opnd => Make_Op_Lt (Loc, Left_Opnd => New_Occurrence_Of (Tnn, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_First, Prefix => New_Occurrence_Of (Target_Type, Loc))), Right_Opnd => Make_Op_Gt (Loc, Left_Opnd => New_Occurrence_Of (Tnn, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Last, Prefix => New_Occurrence_Of (Target_Type, Loc)))), Reason => CE_Range_Check_Failed))); Rewrite (N, New_Occurrence_Of (Tnn, Loc)); Analyze_And_Resolve (N, Btyp); end Real_Range_Check; ----------------------------- -- Has_Extra_Accessibility -- ----------------------------- -- Returns true for a formal of an anonymous access type or for -- an Ada 2012-style stand-alone object of an anonymous access type. function Has_Extra_Accessibility (Id : Entity_Id) return Boolean is begin if Is_Formal (Id) or else Ekind_In (Id, E_Constant, E_Variable) then return Present (Effective_Extra_Accessibility (Id)); else return False; end if; end Has_Extra_Accessibility; -- Start of processing for Expand_N_Type_Conversion begin -- Nothing at all to do if conversion is to the identical type so remove -- the conversion completely, it is useless, except that it may carry -- an Assignment_OK attribute, which must be propagated to the operand. if Operand_Type = Target_Type then if Assignment_OK (N) then Set_Assignment_OK (Operand); end if; Rewrite (N, Relocate_Node (Operand)); goto Done; end if; -- Nothing to do if this is the second argument of read. This is a -- "backwards" conversion that will be handled by the specialized code -- in attribute processing. if Nkind (Parent (N)) = N_Attribute_Reference and then Attribute_Name (Parent (N)) = Name_Read and then Next (First (Expressions (Parent (N)))) = N then goto Done; end if; -- Check for case of converting to a type that has an invariant -- associated with it. This required an invariant check. We convert -- typ (expr) -- into -- do invariant_check (typ (expr)) in typ (expr); -- using Duplicate_Subexpr to avoid multiple side effects -- Note: the Comes_From_Source check, and then the resetting of this -- flag prevents what would otherwise be an infinite recursion. if Has_Invariants (Target_Type) and then Present (Invariant_Procedure (Target_Type)) and then Comes_From_Source (N) then Set_Comes_From_Source (N, False); Rewrite (N, Make_Expression_With_Actions (Loc, Actions => New_List ( Make_Invariant_Call (Duplicate_Subexpr (N))), Expression => Duplicate_Subexpr_No_Checks (N))); Analyze_And_Resolve (N, Target_Type); goto Done; end if; -- Here if we may need to expand conversion -- If the operand of the type conversion is an arithmetic operation on -- signed integers, and the based type of the signed integer type in -- question is smaller than Standard.Integer, we promote both of the -- operands to type Integer. -- For example, if we have -- target-type (opnd1 + opnd2) -- and opnd1 and opnd2 are of type short integer, then we rewrite -- this as: -- target-type (integer(opnd1) + integer(opnd2)) -- We do this because we are always allowed to compute in a larger type -- if we do the right thing with the result, and in this case we are -- going to do a conversion which will do an appropriate check to make -- sure that things are in range of the target type in any case. This -- avoids some unnecessary intermediate overflows. -- We might consider a similar transformation in the case where the -- target is a real type or a 64-bit integer type, and the operand -- is an arithmetic operation using a 32-bit integer type. However, -- we do not bother with this case, because it could cause significant -- inefficiencies on 32-bit machines. On a 64-bit machine it would be -- much cheaper, but we don't want different behavior on 32-bit and -- 64-bit machines. Note that the exclusion of the 64-bit case also -- handles the configurable run-time cases where 64-bit arithmetic -- may simply be unavailable. -- Note: this circuit is partially redundant with respect to the circuit -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in -- the processing here. Also we still need the Checks circuit, since we -- have to be sure not to generate junk overflow checks in the first -- place, since it would be trick to remove them here! if Integer_Promotion_Possible (N) then -- All conditions met, go ahead with transformation declare Opnd : Node_Id; L, R : Node_Id; begin R := Make_Type_Conversion (Loc, Subtype_Mark => New_Reference_To (Standard_Integer, Loc), Expression => Relocate_Node (Right_Opnd (Operand))); Opnd := New_Op_Node (Nkind (Operand), Loc); Set_Right_Opnd (Opnd, R); if Nkind (Operand) in N_Binary_Op then L := Make_Type_Conversion (Loc, Subtype_Mark => New_Reference_To (Standard_Integer, Loc), Expression => Relocate_Node (Left_Opnd (Operand))); Set_Left_Opnd (Opnd, L); end if; Rewrite (N, Make_Type_Conversion (Loc, Subtype_Mark => Relocate_Node (Subtype_Mark (N)), Expression => Opnd)); Analyze_And_Resolve (N, Target_Type); goto Done; end; end if; -- Do validity check if validity checking operands if Validity_Checks_On and then Validity_Check_Operands then Ensure_Valid (Operand); end if; -- Special case of converting from non-standard boolean type if Is_Boolean_Type (Operand_Type) and then (Nonzero_Is_True (Operand_Type)) then Adjust_Condition (Operand); Set_Etype (Operand, Standard_Boolean); Operand_Type := Standard_Boolean; end if; -- Case of converting to an access type if Is_Access_Type (Target_Type) then -- Apply an accessibility check when the conversion operand is an -- access parameter (or a renaming thereof), unless conversion was -- expanded from an Unchecked_ or Unrestricted_Access attribute. -- Note that other checks may still need to be applied below (such -- as tagged type checks). if Is_Entity_Name (Operand) and then Has_Extra_Accessibility (Entity (Operand)) and then Ekind (Etype (Operand)) = E_Anonymous_Access_Type and then (Nkind (Original_Node (N)) /= N_Attribute_Reference or else Attribute_Name (Original_Node (N)) = Name_Access) then Apply_Accessibility_Check (Operand, Target_Type, Insert_Node => Operand); -- If the level of the operand type is statically deeper than the -- level of the target type, then force Program_Error. Note that this -- can only occur for cases where the attribute is within the body of -- an instantiation (otherwise the conversion will already have been -- rejected as illegal). Note: warnings are issued by the analyzer -- for the instance cases. elsif In_Instance_Body and then Type_Access_Level (Operand_Type) > Type_Access_Level (Target_Type) then Raise_Accessibility_Error; -- When the operand is a selected access discriminant the check needs -- to be made against the level of the object denoted by the prefix -- of the selected name. Force Program_Error for this case as well -- (this accessibility violation can only happen if within the body -- of an instantiation). elsif In_Instance_Body and then Ekind (Operand_Type) = E_Anonymous_Access_Type and then Nkind (Operand) = N_Selected_Component and then Object_Access_Level (Operand) > Type_Access_Level (Target_Type) then Raise_Accessibility_Error; goto Done; end if; end if; -- Case of conversions of tagged types and access to tagged types -- When needed, that is to say when the expression is class-wide, Add -- runtime a tag check for (strict) downward conversion by using the -- membership test, generating: -- [constraint_error when Operand not in Target_Type'Class] -- or in the access type case -- [constraint_error -- when Operand /= null -- and then Operand.all not in -- Designated_Type (Target_Type)'Class] if (Is_Access_Type (Target_Type) and then Is_Tagged_Type (Designated_Type (Target_Type))) or else Is_Tagged_Type (Target_Type) then -- Do not do any expansion in the access type case if the parent is a -- renaming, since this is an error situation which will be caught by -- Sem_Ch8, and the expansion can interfere with this error check. if Is_Access_Type (Target_Type) and then Is_Renamed_Object (N) then goto Done; end if; -- Otherwise, proceed with processing tagged conversion Tagged_Conversion : declare Actual_Op_Typ : Entity_Id; Actual_Targ_Typ : Entity_Id; Make_Conversion : Boolean := False; Root_Op_Typ : Entity_Id; procedure Make_Tag_Check (Targ_Typ : Entity_Id); -- Create a membership check to test whether Operand is a member -- of Targ_Typ. If the original Target_Type is an access, include -- a test for null value. The check is inserted at N. -------------------- -- Make_Tag_Check -- -------------------- procedure Make_Tag_Check (Targ_Typ : Entity_Id) is Cond : Node_Id; begin -- Generate: -- [Constraint_Error -- when Operand /= null -- and then Operand.all not in Targ_Typ] if Is_Access_Type (Target_Type) then Cond := Make_And_Then (Loc, Left_Opnd => Make_Op_Ne (Loc, Left_Opnd => Duplicate_Subexpr_No_Checks (Operand), Right_Opnd => Make_Null (Loc)), Right_Opnd => Make_Not_In (Loc, Left_Opnd => Make_Explicit_Dereference (Loc, Prefix => Duplicate_Subexpr_No_Checks (Operand)), Right_Opnd => New_Reference_To (Targ_Typ, Loc))); -- Generate: -- [Constraint_Error when Operand not in Targ_Typ] else Cond := Make_Not_In (Loc, Left_Opnd => Duplicate_Subexpr_No_Checks (Operand), Right_Opnd => New_Reference_To (Targ_Typ, Loc)); end if; Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Cond, Reason => CE_Tag_Check_Failed)); end Make_Tag_Check; -- Start of processing for Tagged_Conversion begin -- Handle entities from the limited view if Is_Access_Type (Operand_Type) then Actual_Op_Typ := Available_View (Designated_Type (Operand_Type)); else Actual_Op_Typ := Operand_Type; end if; if Is_Access_Type (Target_Type) then Actual_Targ_Typ := Available_View (Designated_Type (Target_Type)); else Actual_Targ_Typ := Target_Type; end if; Root_Op_Typ := Root_Type (Actual_Op_Typ); -- Ada 2005 (AI-251): Handle interface type conversion if Is_Interface (Actual_Op_Typ) then Expand_Interface_Conversion (N, Is_Static => False); goto Done; end if; if not Tag_Checks_Suppressed (Actual_Targ_Typ) then -- Create a runtime tag check for a downward class-wide type -- conversion. if Is_Class_Wide_Type (Actual_Op_Typ) and then Actual_Op_Typ /= Actual_Targ_Typ and then Root_Op_Typ /= Actual_Targ_Typ and then Is_Ancestor (Root_Op_Typ, Actual_Targ_Typ, Use_Full_View => True) then Make_Tag_Check (Class_Wide_Type (Actual_Targ_Typ)); Make_Conversion := True; end if; -- AI05-0073: If the result subtype of the function is defined -- by an access_definition designating a specific tagged type -- T, a check is made that the result value is null or the tag -- of the object designated by the result value identifies T. -- Constraint_Error is raised if this check fails. if Nkind (Parent (N)) = Sinfo.N_Return_Statement then declare Func : Entity_Id; Func_Typ : Entity_Id; begin -- Climb scope stack looking for the enclosing function Func := Current_Scope; while Present (Func) and then Ekind (Func) /= E_Function loop Func := Scope (Func); end loop; -- The function's return subtype must be defined using -- an access definition. if Nkind (Result_Definition (Parent (Func))) = N_Access_Definition then Func_Typ := Directly_Designated_Type (Etype (Func)); -- The return subtype denotes a specific tagged type, -- in other words, a non class-wide type. if Is_Tagged_Type (Func_Typ) and then not Is_Class_Wide_Type (Func_Typ) then Make_Tag_Check (Actual_Targ_Typ); Make_Conversion := True; end if; end if; end; end if; -- We have generated a tag check for either a class-wide type -- conversion or for AI05-0073. if Make_Conversion then declare Conv : Node_Id; begin Conv := Make_Unchecked_Type_Conversion (Loc, Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), Expression => Relocate_Node (Expression (N))); Rewrite (N, Conv); Analyze_And_Resolve (N, Target_Type); end; end if; end if; end Tagged_Conversion; -- Case of other access type conversions elsif Is_Access_Type (Target_Type) then Apply_Constraint_Check (Operand, Target_Type); -- Case of conversions from a fixed-point type -- These conversions require special expansion and processing, found in -- the Exp_Fixd package. We ignore cases where Conversion_OK is set, -- since from a semantic point of view, these are simple integer -- conversions, which do not need further processing. elsif Is_Fixed_Point_Type (Operand_Type) and then not Conversion_OK (N) then -- We should never see universal fixed at this case, since the -- expansion of the constituent divide or multiply should have -- eliminated the explicit mention of universal fixed. pragma Assert (Operand_Type /= Universal_Fixed); -- Check for special case of the conversion to universal real that -- occurs as a result of the use of a round attribute. In this case, -- the real type for the conversion is taken from the target type of -- the Round attribute and the result must be marked as rounded. if Target_Type = Universal_Real and then Nkind (Parent (N)) = N_Attribute_Reference and then Attribute_Name (Parent (N)) = Name_Round then Set_Rounded_Result (N); Set_Etype (N, Etype (Parent (N))); end if; -- Otherwise do correct fixed-conversion, but skip these if the -- Conversion_OK flag is set, because from a semantic point of view -- these are simple integer conversions needing no further processing -- (the backend will simply treat them as integers). if not Conversion_OK (N) then if Is_Fixed_Point_Type (Etype (N)) then Expand_Convert_Fixed_To_Fixed (N); Real_Range_Check; elsif Is_Integer_Type (Etype (N)) then Expand_Convert_Fixed_To_Integer (N); else pragma Assert (Is_Floating_Point_Type (Etype (N))); Expand_Convert_Fixed_To_Float (N); Real_Range_Check; end if; end if; -- Case of conversions to a fixed-point type -- These conversions require special expansion and processing, found in -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set, -- since from a semantic point of view, these are simple integer -- conversions, which do not need further processing. elsif Is_Fixed_Point_Type (Target_Type) and then not Conversion_OK (N) then if Is_Integer_Type (Operand_Type) then Expand_Convert_Integer_To_Fixed (N); Real_Range_Check; else pragma Assert (Is_Floating_Point_Type (Operand_Type)); Expand_Convert_Float_To_Fixed (N); Real_Range_Check; end if; -- Case of float-to-integer conversions -- We also handle float-to-fixed conversions with Conversion_OK set -- since semantically the fixed-point target is treated as though it -- were an integer in such cases. elsif Is_Floating_Point_Type (Operand_Type) and then (Is_Integer_Type (Target_Type) or else (Is_Fixed_Point_Type (Target_Type) and then Conversion_OK (N))) then -- One more check here, gcc is still not able to do conversions of -- this type with proper overflow checking, and so gigi is doing an -- approximation of what is required by doing floating-point compares -- with the end-point. But that can lose precision in some cases, and -- give a wrong result. Converting the operand to Universal_Real is -- helpful, but still does not catch all cases with 64-bit integers -- on targets with only 64-bit floats. -- The above comment seems obsoleted by Apply_Float_Conversion_Check -- Can this code be removed ??? if Do_Range_Check (Operand) then Rewrite (Operand, Make_Type_Conversion (Loc, Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc), Expression => Relocate_Node (Operand))); Set_Etype (Operand, Universal_Real); Enable_Range_Check (Operand); Set_Do_Range_Check (Expression (Operand), False); end if; -- Case of array conversions -- Expansion of array conversions, add required length/range checks but -- only do this if there is no change of representation. For handling of -- this case, see Handle_Changed_Representation. elsif Is_Array_Type (Target_Type) then if Is_Constrained (Target_Type) then Apply_Length_Check (Operand, Target_Type); else Apply_Range_Check (Operand, Target_Type); end if; Handle_Changed_Representation; -- Case of conversions of discriminated types -- Add required discriminant checks if target is constrained. Again this -- change is skipped if we have a change of representation. elsif Has_Discriminants (Target_Type) and then Is_Constrained (Target_Type) then Apply_Discriminant_Check (Operand, Target_Type); Handle_Changed_Representation; -- Case of all other record conversions. The only processing required -- is to check for a change of representation requiring the special -- assignment processing. elsif Is_Record_Type (Target_Type) then -- Ada 2005 (AI-216): Program_Error is raised when converting from -- a derived Unchecked_Union type to an unconstrained type that is -- not Unchecked_Union if the operand lacks inferable discriminants. if Is_Derived_Type (Operand_Type) and then Is_Unchecked_Union (Base_Type (Operand_Type)) and then not Is_Constrained (Target_Type) and then not Is_Unchecked_Union (Base_Type (Target_Type)) and then not Has_Inferable_Discriminants (Operand) then -- To prevent Gigi from generating illegal code, we generate a -- Program_Error node, but we give it the target type of the -- conversion. declare PE : constant Node_Id := Make_Raise_Program_Error (Loc, Reason => PE_Unchecked_Union_Restriction); begin Set_Etype (PE, Target_Type); Rewrite (N, PE); end; else Handle_Changed_Representation; end if; -- Case of conversions of enumeration types elsif Is_Enumeration_Type (Target_Type) then -- Special processing is required if there is a change of -- representation (from enumeration representation clauses). if not Same_Representation (Target_Type, Operand_Type) then -- Convert: x(y) to x'val (ytyp'val (y)) Rewrite (N, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Target_Type, Loc), Attribute_Name => Name_Val, Expressions => New_List ( Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Operand_Type, Loc), Attribute_Name => Name_Pos, Expressions => New_List (Operand))))); Analyze_And_Resolve (N, Target_Type); end if; -- Case of conversions to floating-point elsif Is_Floating_Point_Type (Target_Type) then Real_Range_Check; end if; -- At this stage, either the conversion node has been transformed into -- some other equivalent expression, or left as a conversion that can be -- handled by Gigi, in the following cases: -- Conversions with no change of representation or type -- Numeric conversions involving integer, floating- and fixed-point -- values. Fixed-point values are allowed only if Conversion_OK is -- set, i.e. if the fixed-point values are to be treated as integers. -- No other conversions should be passed to Gigi -- Check: are these rules stated in sinfo??? if so, why restate here??? -- The only remaining step is to generate a range check if we still have -- a type conversion at this stage and Do_Range_Check is set. For now we -- do this only for conversions of discrete types. if Nkind (N) = N_Type_Conversion and then Is_Discrete_Type (Etype (N)) then declare Expr : constant Node_Id := Expression (N); Ftyp : Entity_Id; Ityp : Entity_Id; begin if Do_Range_Check (Expr) and then Is_Discrete_Type (Etype (Expr)) then Set_Do_Range_Check (Expr, False); -- Before we do a range check, we have to deal with treating a -- fixed-point operand as an integer. The way we do this is -- simply to do an unchecked conversion to an appropriate -- integer type large enough to hold the result. -- This code is not active yet, because we are only dealing -- with discrete types so far ??? if Nkind (Expr) in N_Has_Treat_Fixed_As_Integer and then Treat_Fixed_As_Integer (Expr) then Ftyp := Base_Type (Etype (Expr)); if Esize (Ftyp) >= Esize (Standard_Integer) then Ityp := Standard_Long_Long_Integer; else Ityp := Standard_Integer; end if; Rewrite (Expr, Unchecked_Convert_To (Ityp, Expr)); end if; -- Reset overflow flag, since the range check will include -- dealing with possible overflow, and generate the check. If -- Address is either a source type or target type, suppress -- range check to avoid typing anomalies when it is a visible -- integer type. Set_Do_Overflow_Check (N, False); if not Is_Descendent_Of_Address (Etype (Expr)) and then not Is_Descendent_Of_Address (Target_Type) then Generate_Range_Check (Expr, Target_Type, CE_Range_Check_Failed); end if; end if; end; end if; -- Final step, if the result is a type conversion involving Vax_Float -- types, then it is subject for further special processing. if Nkind (N) = N_Type_Conversion and then (Vax_Float (Operand_Type) or else Vax_Float (Target_Type)) then Expand_Vax_Conversion (N); goto Done; end if; -- Here at end of processing <<Done>> -- Apply predicate check if required. Note that we can't just call -- Apply_Predicate_Check here, because the type looks right after -- the conversion and it would omit the check. The Comes_From_Source -- guard is necessary to prevent infinite recursions when we generate -- internal conversions for the purpose of checking predicates. if Present (Predicate_Function (Target_Type)) and then Target_Type /= Operand_Type and then Comes_From_Source (N) then declare New_Expr : constant Node_Id := Duplicate_Subexpr (N); begin -- Avoid infinite recursion on the subsequent expansion of -- of the copy of the original type conversion. Set_Comes_From_Source (New_Expr, False); Insert_Action (N, Make_Predicate_Check (Target_Type, New_Expr)); end; end if; end Expand_N_Type_Conversion; ----------------------------------- -- Expand_N_Unchecked_Expression -- ----------------------------------- -- Remove the unchecked expression node from the tree. Its job was simply -- to make sure that its constituent expression was handled with checks -- off, and now that that is done, we can remove it from the tree, and -- indeed must, since Gigi does not expect to see these nodes. procedure Expand_N_Unchecked_Expression (N : Node_Id) is Exp : constant Node_Id := Expression (N); begin Set_Assignment_OK (Exp, Assignment_OK (N) or else Assignment_OK (Exp)); Rewrite (N, Exp); end Expand_N_Unchecked_Expression; ---------------------------------------- -- Expand_N_Unchecked_Type_Conversion -- ---------------------------------------- -- If this cannot be handled by Gigi and we haven't already made a -- temporary for it, do it now. procedure Expand_N_Unchecked_Type_Conversion (N : Node_Id) is Target_Type : constant Entity_Id := Etype (N); Operand : constant Node_Id := Expression (N); Operand_Type : constant Entity_Id := Etype (Operand); begin -- Nothing at all to do if conversion is to the identical type so remove -- the conversion completely, it is useless, except that it may carry -- an Assignment_OK indication which must be propagated to the operand. if Operand_Type = Target_Type then -- Code duplicates Expand_N_Unchecked_Expression above, factor??? if Assignment_OK (N) then Set_Assignment_OK (Operand); end if; Rewrite (N, Relocate_Node (Operand)); return; end if; -- If we have a conversion of a compile time known value to a target -- type and the value is in range of the target type, then we can simply -- replace the construct by an integer literal of the correct type. We -- only apply this to integer types being converted. Possibly it may -- apply in other cases, but it is too much trouble to worry about. -- Note that we do not do this transformation if the Kill_Range_Check -- flag is set, since then the value may be outside the expected range. -- This happens in the Normalize_Scalars case. -- We also skip this if either the target or operand type is biased -- because in this case, the unchecked conversion is supposed to -- preserve the bit pattern, not the integer value. if Is_Integer_Type (Target_Type) and then not Has_Biased_Representation (Target_Type) and then Is_Integer_Type (Operand_Type) and then not Has_Biased_Representation (Operand_Type) and then Compile_Time_Known_Value (Operand) and then not Kill_Range_Check (N) then declare Val : constant Uint := Expr_Value (Operand); begin if Compile_Time_Known_Value (Type_Low_Bound (Target_Type)) and then Compile_Time_Known_Value (Type_High_Bound (Target_Type)) and then Val >= Expr_Value (Type_Low_Bound (Target_Type)) and then Val <= Expr_Value (Type_High_Bound (Target_Type)) then Rewrite (N, Make_Integer_Literal (Sloc (N), Val)); -- If Address is the target type, just set the type to avoid a -- spurious type error on the literal when Address is a visible -- integer type. if Is_Descendent_Of_Address (Target_Type) then Set_Etype (N, Target_Type); else Analyze_And_Resolve (N, Target_Type); end if; return; end if; end; end if; -- Nothing to do if conversion is safe if Safe_Unchecked_Type_Conversion (N) then return; end if; -- Otherwise force evaluation unless Assignment_OK flag is set (this -- flag indicates ??? -- more comments needed here) if Assignment_OK (N) then null; else Force_Evaluation (N); end if; end Expand_N_Unchecked_Type_Conversion; ---------------------------- -- Expand_Record_Equality -- ---------------------------- -- For non-variant records, Equality is expanded when needed into: -- and then Lhs.Discr1 = Rhs.Discr1 -- and then ... -- and then Lhs.Discrn = Rhs.Discrn -- and then Lhs.Cmp1 = Rhs.Cmp1 -- and then ... -- and then Lhs.Cmpn = Rhs.Cmpn -- The expression is folded by the back-end for adjacent fields. This -- function is called for tagged record in only one occasion: for imple- -- menting predefined primitive equality (see Predefined_Primitives_Bodies) -- otherwise the primitive "=" is used directly. function Expand_Record_Equality (Nod : Node_Id; Typ : Entity_Id; Lhs : Node_Id; Rhs : Node_Id; Bodies : List_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Nod); Result : Node_Id; C : Entity_Id; First_Time : Boolean := True; function Suitable_Element (C : Entity_Id) return Entity_Id; -- Return the first field to compare beginning with C, skipping the -- inherited components. ---------------------- -- Suitable_Element -- ---------------------- function Suitable_Element (C : Entity_Id) return Entity_Id is begin if No (C) then return Empty; elsif Ekind (C) /= E_Discriminant and then Ekind (C) /= E_Component then return Suitable_Element (Next_Entity (C)); elsif Is_Tagged_Type (Typ) and then C /= Original_Record_Component (C) then return Suitable_Element (Next_Entity (C)); elsif Chars (C) = Name_uTag then return Suitable_Element (Next_Entity (C)); -- The .NET/JVM version of type Root_Controlled contains two fields -- which should not be considered part of the object. To achieve -- proper equiality between two controlled objects on .NET/JVM, skip -- field _parent whenever it is of type Root_Controlled. elsif Chars (C) = Name_uParent and then VM_Target /= No_VM and then Etype (C) = RTE (RE_Root_Controlled) then return Suitable_Element (Next_Entity (C)); elsif Is_Interface (Etype (C)) then return Suitable_Element (Next_Entity (C)); else return C; end if; end Suitable_Element; -- Start of processing for Expand_Record_Equality begin -- Generates the following code: (assuming that Typ has one Discr and -- component C2 is also a record) -- True -- and then Lhs.Discr1 = Rhs.Discr1 -- and then Lhs.C1 = Rhs.C1 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn -- and then ... -- and then Lhs.Cmpn = Rhs.Cmpn Result := New_Reference_To (Standard_True, Loc); C := Suitable_Element (First_Entity (Typ)); while Present (C) loop declare New_Lhs : Node_Id; New_Rhs : Node_Id; Check : Node_Id; begin if First_Time then First_Time := False; New_Lhs := Lhs; New_Rhs := Rhs; else New_Lhs := New_Copy_Tree (Lhs); New_Rhs := New_Copy_Tree (Rhs); end if; Check := Expand_Composite_Equality (Nod, Etype (C), Lhs => Make_Selected_Component (Loc, Prefix => New_Lhs, Selector_Name => New_Reference_To (C, Loc)), Rhs => Make_Selected_Component (Loc, Prefix => New_Rhs, Selector_Name => New_Reference_To (C, Loc)), Bodies => Bodies); -- If some (sub)component is an unchecked_union, the whole -- operation will raise program error. if Nkind (Check) = N_Raise_Program_Error then Result := Check; Set_Etype (Result, Standard_Boolean); exit; else Result := Make_And_Then (Loc, Left_Opnd => Result, Right_Opnd => Check); end if; end; C := Suitable_Element (Next_Entity (C)); end loop; return Result; end Expand_Record_Equality; --------------------------- -- Expand_Set_Membership -- --------------------------- procedure Expand_Set_Membership (N : Node_Id) is Lop : constant Node_Id := Left_Opnd (N); Alt : Node_Id; Res : Node_Id; function Make_Cond (Alt : Node_Id) return Node_Id; -- If the alternative is a subtype mark, create a simple membership -- test. Otherwise create an equality test for it. --------------- -- Make_Cond -- --------------- function Make_Cond (Alt : Node_Id) return Node_Id is Cond : Node_Id; L : constant Node_Id := New_Copy (Lop); R : constant Node_Id := Relocate_Node (Alt); begin if (Is_Entity_Name (Alt) and then Is_Type (Entity (Alt))) or else Nkind (Alt) = N_Range then Cond := Make_In (Sloc (Alt), Left_Opnd => L, Right_Opnd => R); else Cond := Make_Op_Eq (Sloc (Alt), Left_Opnd => L, Right_Opnd => R); end if; return Cond; end Make_Cond; -- Start of processing for Expand_Set_Membership begin Remove_Side_Effects (Lop); Alt := Last (Alternatives (N)); Res := Make_Cond (Alt); Prev (Alt); while Present (Alt) loop Res := Make_Or_Else (Sloc (Alt), Left_Opnd => Make_Cond (Alt), Right_Opnd => Res); Prev (Alt); end loop; Rewrite (N, Res); Analyze_And_Resolve (N, Standard_Boolean); end Expand_Set_Membership; ----------------------------------- -- Expand_Short_Circuit_Operator -- ----------------------------------- -- Deal with special expansion if actions are present for the right operand -- and deal with optimizing case of arguments being True or False. We also -- deal with the special case of non-standard boolean values. procedure Expand_Short_Circuit_Operator (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Left : constant Node_Id := Left_Opnd (N); Right : constant Node_Id := Right_Opnd (N); LocR : constant Source_Ptr := Sloc (Right); Actlist : List_Id; Shortcut_Value : constant Boolean := Nkind (N) = N_Or_Else; Shortcut_Ent : constant Entity_Id := Boolean_Literals (Shortcut_Value); -- If Left = Shortcut_Value then Right need not be evaluated function Make_Test_Expr (Opnd : Node_Id) return Node_Id; -- For Opnd a boolean expression, return a Boolean expression equivalent -- to Opnd /= Shortcut_Value. -------------------- -- Make_Test_Expr -- -------------------- function Make_Test_Expr (Opnd : Node_Id) return Node_Id is begin if Shortcut_Value then return Make_Op_Not (Sloc (Opnd), Opnd); else return Opnd; end if; end Make_Test_Expr; Op_Var : Entity_Id; -- Entity for a temporary variable holding the value of the operator, -- used for expansion in the case where actions are present. -- Start of processing for Expand_Short_Circuit_Operator begin -- Deal with non-standard booleans if Is_Boolean_Type (Typ) then Adjust_Condition (Left); Adjust_Condition (Right); Set_Etype (N, Standard_Boolean); end if; -- Check for cases where left argument is known to be True or False if Compile_Time_Known_Value (Left) then -- Mark SCO for left condition as compile time known if Generate_SCO and then Comes_From_Source (Left) then Set_SCO_Condition (Left, Expr_Value_E (Left) = Standard_True); end if; -- Rewrite True AND THEN Right / False OR ELSE Right to Right. -- Any actions associated with Right will be executed unconditionally -- and can thus be inserted into the tree unconditionally. if Expr_Value_E (Left) /= Shortcut_Ent then if Present (Actions (N)) then Insert_Actions (N, Actions (N)); end if; Rewrite (N, Right); -- Rewrite False AND THEN Right / True OR ELSE Right to Left. -- In this case we can forget the actions associated with Right, -- since they will never be executed. else Kill_Dead_Code (Right); Kill_Dead_Code (Actions (N)); Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc)); end if; Adjust_Result_Type (N, Typ); return; end if; -- If Actions are present for the right operand, we have to do some -- special processing. We can't just let these actions filter back into -- code preceding the short circuit (which is what would have happened -- if we had not trapped them in the short-circuit form), since they -- must only be executed if the right operand of the short circuit is -- executed and not otherwise. -- the temporary variable C. if Present (Actions (N)) then Actlist := Actions (N); -- The old approach is to expand: -- left AND THEN right -- into -- C : Boolean := False; -- IF left THEN -- Actions; -- IF right THEN -- C := True; -- END IF; -- END IF; -- and finally rewrite the operator into a reference to C. Similarly -- for left OR ELSE right, with negated values. Note that this -- rewrite causes some difficulties for coverage analysis because -- of the introduction of the new variable C, which obscures the -- structure of the test. -- We use this "old approach" if use of N_Expression_With_Actions -- is False (see description in Opt of when this is or is not set). if not Use_Expression_With_Actions then Op_Var := Make_Temporary (Loc, 'C', Related_Node => N); Insert_Action (N, Make_Object_Declaration (Loc, Defining_Identifier => Op_Var, Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc), Expression => New_Occurrence_Of (Shortcut_Ent, Loc))); Append_To (Actlist, Make_Implicit_If_Statement (Right, Condition => Make_Test_Expr (Right), Then_Statements => New_List ( Make_Assignment_Statement (LocR, Name => New_Occurrence_Of (Op_Var, LocR), Expression => New_Occurrence_Of (Boolean_Literals (not Shortcut_Value), LocR))))); Insert_Action (N, Make_Implicit_If_Statement (Left, Condition => Make_Test_Expr (Left), Then_Statements => Actlist)); Rewrite (N, New_Occurrence_Of (Op_Var, Loc)); Analyze_And_Resolve (N, Standard_Boolean); -- The new approach, activated for now by the use of debug flag -- -gnatd.X is to use the new Expression_With_Actions node for the -- right operand of the short-circuit form. This should solve the -- traceability problems for coverage analysis. else Rewrite (Right, Make_Expression_With_Actions (LocR, Expression => Relocate_Node (Right), Actions => Actlist)); Set_Actions (N, No_List); Analyze_And_Resolve (Right, Standard_Boolean); end if; Adjust_Result_Type (N, Typ); return; end if; -- No actions present, check for cases of right argument True/False if Compile_Time_Known_Value (Right) then -- Mark SCO for left condition as compile time known if Generate_SCO and then Comes_From_Source (Right) then Set_SCO_Condition (Right, Expr_Value_E (Right) = Standard_True); end if; -- Change (Left and then True), (Left or else False) to Left. -- Note that we know there are no actions associated with the right -- operand, since we just checked for this case above. if Expr_Value_E (Right) /= Shortcut_Ent then Rewrite (N, Left); -- Change (Left and then False), (Left or else True) to Right, -- making sure to preserve any side effects associated with the Left -- operand. else Remove_Side_Effects (Left); Rewrite (N, New_Occurrence_Of (Shortcut_Ent, Loc)); end if; end if; Adjust_Result_Type (N, Typ); end Expand_Short_Circuit_Operator; ------------------------------------- -- Fixup_Universal_Fixed_Operation -- ------------------------------------- procedure Fixup_Universal_Fixed_Operation (N : Node_Id) is Conv : constant Node_Id := Parent (N); begin -- We must have a type conversion immediately above us pragma Assert (Nkind (Conv) = N_Type_Conversion); -- Normally the type conversion gives our target type. The exception -- occurs in the case of the Round attribute, where the conversion -- will be to universal real, and our real type comes from the Round -- attribute (as well as an indication that we must round the result) if Nkind (Parent (Conv)) = N_Attribute_Reference and then Attribute_Name (Parent (Conv)) = Name_Round then Set_Etype (N, Etype (Parent (Conv))); Set_Rounded_Result (N); -- Normal case where type comes from conversion above us else Set_Etype (N, Etype (Conv)); end if; end Fixup_Universal_Fixed_Operation; --------------------------------- -- Has_Inferable_Discriminants -- --------------------------------- function Has_Inferable_Discriminants (N : Node_Id) return Boolean is function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean; -- Determines whether the left-most prefix of a selected component is a -- formal parameter in a subprogram. Assumes N is a selected component. -------------------------------- -- Prefix_Is_Formal_Parameter -- -------------------------------- function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is Sel_Comp : Node_Id := N; begin -- Move to the left-most prefix by climbing up the tree while Present (Parent (Sel_Comp)) and then Nkind (Parent (Sel_Comp)) = N_Selected_Component loop Sel_Comp := Parent (Sel_Comp); end loop; return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind; end Prefix_Is_Formal_Parameter; -- Start of processing for Has_Inferable_Discriminants begin -- For identifiers and indexed components, it is sufficient to have a -- constrained Unchecked_Union nominal subtype. if Nkind_In (N, N_Identifier, N_Indexed_Component) then return Is_Unchecked_Union (Base_Type (Etype (N))) and then Is_Constrained (Etype (N)); -- For selected components, the subtype of the selector must be a -- constrained Unchecked_Union. If the component is subject to a -- per-object constraint, then the enclosing object must have inferable -- discriminants. elsif Nkind (N) = N_Selected_Component then if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then -- A small hack. If we have a per-object constrained selected -- component of a formal parameter, return True since we do not -- know the actual parameter association yet. if Prefix_Is_Formal_Parameter (N) then return True; end if; -- Otherwise, check the enclosing object and the selector return Has_Inferable_Discriminants (Prefix (N)) and then Has_Inferable_Discriminants (Selector_Name (N)); end if; -- The call to Has_Inferable_Discriminants will determine whether -- the selector has a constrained Unchecked_Union nominal type. return Has_Inferable_Discriminants (Selector_Name (N)); -- A qualified expression has inferable discriminants if its subtype -- mark is a constrained Unchecked_Union subtype. elsif Nkind (N) = N_Qualified_Expression then return Is_Unchecked_Union (Subtype_Mark (N)) and then Is_Constrained (Subtype_Mark (N)); end if; return False; end Has_Inferable_Discriminants; ------------------------------- -- Insert_Dereference_Action -- ------------------------------- procedure Insert_Dereference_Action (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Pool : constant Entity_Id := Associated_Storage_Pool (Typ); Pnod : constant Node_Id := Parent (N); function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean; -- Return true if type of P is derived from Checked_Pool; ----------------------------- -- Is_Checked_Storage_Pool -- ----------------------------- function Is_Checked_Storage_Pool (P : Entity_Id) return Boolean is T : Entity_Id; begin if No (P) then return False; end if; T := Etype (P); while T /= Etype (T) loop if Is_RTE (T, RE_Checked_Pool) then return True; else T := Etype (T); end if; end loop; return False; end Is_Checked_Storage_Pool; -- Start of processing for Insert_Dereference_Action begin pragma Assert (Nkind (Pnod) = N_Explicit_Dereference); if not (Is_Checked_Storage_Pool (Pool) and then Comes_From_Source (Original_Node (Pnod))) then return; end if; Insert_Action (N, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( Find_Prim_Op (Etype (Pool), Name_Dereference), Loc), Parameter_Associations => New_List ( -- Pool New_Reference_To (Pool, Loc), -- Storage_Address. We use the attribute Pool_Address, which uses -- the pointer itself to find the address of the object, and which -- handles unconstrained arrays properly by computing the address -- of the template. i.e. the correct address of the corresponding -- allocation. Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_Move_Checks (N), Attribute_Name => Name_Pool_Address), -- Size_In_Storage_Elements Make_Op_Divide (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => Make_Explicit_Dereference (Loc, Duplicate_Subexpr_Move_Checks (N)), Attribute_Name => Name_Size), Right_Opnd => Make_Integer_Literal (Loc, System_Storage_Unit)), -- Alignment Make_Attribute_Reference (Loc, Prefix => Make_Explicit_Dereference (Loc, Duplicate_Subexpr_Move_Checks (N)), Attribute_Name => Name_Alignment)))); exception when RE_Not_Available => return; end Insert_Dereference_Action; -------------------------------- -- Integer_Promotion_Possible -- -------------------------------- function Integer_Promotion_Possible (N : Node_Id) return Boolean is Operand : constant Node_Id := Expression (N); Operand_Type : constant Entity_Id := Etype (Operand); Root_Operand_Type : constant Entity_Id := Root_Type (Operand_Type); begin pragma Assert (Nkind (N) = N_Type_Conversion); return -- We only do the transformation for source constructs. We assume -- that the expander knows what it is doing when it generates code. Comes_From_Source (N) -- If the operand type is Short_Integer or Short_Short_Integer, -- then we will promote to Integer, which is available on all -- targets, and is sufficient to ensure no intermediate overflow. -- Furthermore it is likely to be as efficient or more efficient -- than using the smaller type for the computation so we do this -- unconditionally. and then (Root_Operand_Type = Base_Type (Standard_Short_Integer) or else Root_Operand_Type = Base_Type (Standard_Short_Short_Integer)) -- Test for interesting operation, which includes addition, -- division, exponentiation, multiplication, subtraction, absolute -- value and unary negation. Unary "+" is omitted since it is a -- no-op and thus can't overflow. and then Nkind_In (Operand, N_Op_Abs, N_Op_Add, N_Op_Divide, N_Op_Expon, N_Op_Minus, N_Op_Multiply, N_Op_Subtract); end Integer_Promotion_Possible; ------------------------------ -- Make_Array_Comparison_Op -- ------------------------------ -- This is a hand-coded expansion of the following generic function: -- generic -- type elem is (<>); -- type index is (<>); -- type a is array (index range <>) of elem; -- function Gnnn (X : a; Y: a) return boolean is -- J : index := Y'first; -- begin -- if X'length = 0 then -- return false; -- elsif Y'length = 0 then -- return true; -- else -- for I in X'range loop -- if X (I) = Y (J) then -- if J = Y'last then -- exit; -- else -- J := index'succ (J); -- end if; -- else -- return X (I) > Y (J); -- end if; -- end loop; -- return X'length > Y'length; -- end if; -- end Gnnn; -- Note that since we are essentially doing this expansion by hand, we -- do not need to generate an actual or formal generic part, just the -- instantiated function itself. function Make_Array_Comparison_Op (Typ : Entity_Id; Nod : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Nod); X : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uX); Y : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uY); I : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uI); J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ); Index : constant Entity_Id := Base_Type (Etype (First_Index (Typ))); Loop_Statement : Node_Id; Loop_Body : Node_Id; If_Stat : Node_Id; Inner_If : Node_Id; Final_Expr : Node_Id; Func_Body : Node_Id; Func_Name : Entity_Id; Formals : List_Id; Length1 : Node_Id; Length2 : Node_Id; begin -- if J = Y'last then -- exit; -- else -- J := index'succ (J); -- end if; Inner_If := Make_Implicit_If_Statement (Nod, Condition => Make_Op_Eq (Loc, Left_Opnd => New_Reference_To (J, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Y, Loc), Attribute_Name => Name_Last)), Then_Statements => New_List ( Make_Exit_Statement (Loc)), Else_Statements => New_List ( Make_Assignment_Statement (Loc, Name => New_Reference_To (J, Loc), Expression => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Index, Loc), Attribute_Name => Name_Succ, Expressions => New_List (New_Reference_To (J, Loc)))))); -- if X (I) = Y (J) then -- if ... end if; -- else -- return X (I) > Y (J); -- end if; Loop_Body := Make_Implicit_If_Statement (Nod, Condition => Make_Op_Eq (Loc, Left_Opnd => Make_Indexed_Component (Loc, Prefix => New_Reference_To (X, Loc), Expressions => New_List (New_Reference_To (I, Loc))), Right_Opnd => Make_Indexed_Component (Loc, Prefix => New_Reference_To (Y, Loc), Expressions => New_List (New_Reference_To (J, Loc)))), Then_Statements => New_List (Inner_If), Else_Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => Make_Op_Gt (Loc, Left_Opnd => Make_Indexed_Component (Loc, Prefix => New_Reference_To (X, Loc), Expressions => New_List (New_Reference_To (I, Loc))), Right_Opnd => Make_Indexed_Component (Loc, Prefix => New_Reference_To (Y, Loc), Expressions => New_List ( New_Reference_To (J, Loc))))))); -- for I in X'range loop -- if ... end if; -- end loop; Loop_Statement := Make_Implicit_Loop_Statement (Nod, Identifier => Empty, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => I, Discrete_Subtype_Definition => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (X, Loc), Attribute_Name => Name_Range))), Statements => New_List (Loop_Body)); -- if X'length = 0 then -- return false; -- elsif Y'length = 0 then -- return true; -- else -- for ... loop ... end loop; -- return X'length > Y'length; -- end if; Length1 := Make_Attribute_Reference (Loc, Prefix => New_Reference_To (X, Loc), Attribute_Name => Name_Length); Length2 := Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Y, Loc), Attribute_Name => Name_Length); Final_Expr := Make_Op_Gt (Loc, Left_Opnd => Length1, Right_Opnd => Length2); If_Stat := Make_Implicit_If_Statement (Nod, Condition => Make_Op_Eq (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (X, Loc), Attribute_Name => Name_Length), Right_Opnd => Make_Integer_Literal (Loc, 0)), Then_Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => New_Reference_To (Standard_False, Loc))), Elsif_Parts => New_List ( Make_Elsif_Part (Loc, Condition => Make_Op_Eq (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Y, Loc), Attribute_Name => Name_Length), Right_Opnd => Make_Integer_Literal (Loc, 0)), Then_Statements => New_List ( Make_Simple_Return_Statement (Loc, Expression => New_Reference_To (Standard_True, Loc))))), Else_Statements => New_List ( Loop_Statement, Make_Simple_Return_Statement (Loc, Expression => Final_Expr))); -- (X : a; Y: a) Formals := New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => X, Parameter_Type => New_Reference_To (Typ, Loc)), Make_Parameter_Specification (Loc, Defining_Identifier => Y, Parameter_Type => New_Reference_To (Typ, Loc))); -- function Gnnn (...) return boolean is -- J : index := Y'first; -- begin -- if ... end if; -- end Gnnn; Func_Name := Make_Temporary (Loc, 'G'); Func_Body := Make_Subprogram_Body (Loc, Specification => Make_Function_Specification (Loc, Defining_Unit_Name => Func_Name, Parameter_Specifications => Formals, Result_Definition => New_Reference_To (Standard_Boolean, Loc)), Declarations => New_List ( Make_Object_Declaration (Loc, Defining_Identifier => J, Object_Definition => New_Reference_To (Index, Loc), Expression => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Y, Loc), Attribute_Name => Name_First))), Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (If_Stat))); return Func_Body; end Make_Array_Comparison_Op; --------------------------- -- Make_Boolean_Array_Op -- --------------------------- -- For logical operations on boolean arrays, expand in line the following, -- replacing 'and' with 'or' or 'xor' where needed: -- function Annn (A : typ; B: typ) return typ is -- C : typ; -- begin -- for J in A'range loop -- C (J) := A (J) op B (J); -- end loop; -- return C; -- end Annn; -- Here typ is the boolean array type function Make_Boolean_Array_Op (Typ : Entity_Id; N : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (N); A : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uA); B : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uB); C : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uC); J : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uJ); A_J : Node_Id; B_J : Node_Id; C_J : Node_Id; Op : Node_Id; Formals : List_Id; Func_Name : Entity_Id; Func_Body : Node_Id; Loop_Statement : Node_Id; begin A_J := Make_Indexed_Component (Loc, Prefix => New_Reference_To (A, Loc), Expressions => New_List (New_Reference_To (J, Loc))); B_J := Make_Indexed_Component (Loc, Prefix => New_Reference_To (B, Loc), Expressions => New_List (New_Reference_To (J, Loc))); C_J := Make_Indexed_Component (Loc, Prefix => New_Reference_To (C, Loc), Expressions => New_List (New_Reference_To (J, Loc))); if Nkind (N) = N_Op_And then Op := Make_Op_And (Loc, Left_Opnd => A_J, Right_Opnd => B_J); elsif Nkind (N) = N_Op_Or then Op := Make_Op_Or (Loc, Left_Opnd => A_J, Right_Opnd => B_J); else Op := Make_Op_Xor (Loc, Left_Opnd => A_J, Right_Opnd => B_J); end if; Loop_Statement := Make_Implicit_Loop_Statement (N, Identifier => Empty, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => J, Discrete_Subtype_Definition => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (A, Loc), Attribute_Name => Name_Range))), Statements => New_List ( Make_Assignment_Statement (Loc, Name => C_J, Expression => Op))); Formals := New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => A, Parameter_Type => New_Reference_To (Typ, Loc)), Make_Parameter_Specification (Loc, Defining_Identifier => B, Parameter_Type => New_Reference_To (Typ, Loc))); Func_Name := Make_Temporary (Loc, 'A'); Set_Is_Inlined (Func_Name); Func_Body := Make_Subprogram_Body (Loc, Specification => Make_Function_Specification (Loc, Defining_Unit_Name => Func_Name, Parameter_Specifications => Formals, Result_Definition => New_Reference_To (Typ, Loc)), Declarations => New_List ( Make_Object_Declaration (Loc, Defining_Identifier => C, Object_Definition => New_Reference_To (Typ, Loc))), Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Loop_Statement, Make_Simple_Return_Statement (Loc, Expression => New_Reference_To (C, Loc))))); return Func_Body; end Make_Boolean_Array_Op; -------------------------------- -- Optimize_Length_Comparison -- -------------------------------- procedure Optimize_Length_Comparison (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Result : Node_Id; Left : Node_Id; Right : Node_Id; -- First and Last attribute reference nodes, which end up as left and -- right operands of the optimized result. Is_Zero : Boolean; -- True for comparison operand of zero Comp : Node_Id; -- Comparison operand, set only if Is_Zero is false Ent : Entity_Id; -- Entity whose length is being compared Index : Node_Id; -- Integer_Literal node for length attribute expression, or Empty -- if there is no such expression present. Ityp : Entity_Id; -- Type of array index to which 'Length is applied Op : Node_Kind := Nkind (N); -- Kind of comparison operator, gets flipped if operands backwards function Is_Optimizable (N : Node_Id) return Boolean; -- Tests N to see if it is an optimizable comparison value (defined as -- constant zero or one, or something else where the value is known to -- be positive and in the range of 32-bits, and where the corresponding -- Length value is also known to be 32-bits. If result is true, sets -- Is_Zero, Ityp, and Comp accordingly. function Is_Entity_Length (N : Node_Id) return Boolean; -- Tests if N is a length attribute applied to a simple entity. If so, -- returns True, and sets Ent to the entity, and Index to the integer -- literal provided as an attribute expression, or to Empty if none. -- Also returns True if the expression is a generated type conversion -- whose expression is of the desired form. This latter case arises -- when Apply_Universal_Integer_Attribute_Check installs a conversion -- to check for being in range, which is not needed in this context. -- Returns False if neither condition holds. function Prepare_64 (N : Node_Id) return Node_Id; -- Given a discrete expression, returns a Long_Long_Integer typed -- expression representing the underlying value of the expression. -- This is done with an unchecked conversion to the result type. We -- use unchecked conversion to handle the enumeration type case. ---------------------- -- Is_Entity_Length -- ---------------------- function Is_Entity_Length (N : Node_Id) return Boolean is begin if Nkind (N) = N_Attribute_Reference and then Attribute_Name (N) = Name_Length and then Is_Entity_Name (Prefix (N)) then Ent := Entity (Prefix (N)); if Present (Expressions (N)) then Index := First (Expressions (N)); else Index := Empty; end if; return True; elsif Nkind (N) = N_Type_Conversion and then not Comes_From_Source (N) then return Is_Entity_Length (Expression (N)); else return False; end if; end Is_Entity_Length; -------------------- -- Is_Optimizable -- -------------------- function Is_Optimizable (N : Node_Id) return Boolean is Val : Uint; OK : Boolean; Lo : Uint; Hi : Uint; Indx : Node_Id; begin if Compile_Time_Known_Value (N) then Val := Expr_Value (N); if Val = Uint_0 then Is_Zero := True; Comp := Empty; return True; elsif Val = Uint_1 then Is_Zero := False; Comp := Empty; return True; end if; end if; -- Here we have to make sure of being within 32-bits Determine_Range (N, OK, Lo, Hi, Assume_Valid => True); if not OK or else Lo < Uint_1 or else Hi > UI_From_Int (Int'Last) then return False; end if; -- Comparison value was within range, so now we must check the index -- value to make sure it is also within 32-bits. Indx := First_Index (Etype (Ent)); if Present (Index) then for J in 2 .. UI_To_Int (Intval (Index)) loop Next_Index (Indx); end loop; end if; Ityp := Etype (Indx); if Esize (Ityp) > 32 then return False; end if; Is_Zero := False; Comp := N; return True; end Is_Optimizable; ---------------- -- Prepare_64 -- ---------------- function Prepare_64 (N : Node_Id) return Node_Id is begin return Unchecked_Convert_To (Standard_Long_Long_Integer, N); end Prepare_64; -- Start of processing for Optimize_Length_Comparison begin -- Nothing to do if not a comparison if Op not in N_Op_Compare then return; end if; -- Nothing to do if special -gnatd.P debug flag set if Debug_Flag_Dot_PP then return; end if; -- Ent'Length op 0/1 if Is_Entity_Length (Left_Opnd (N)) and then Is_Optimizable (Right_Opnd (N)) then null; -- 0/1 op Ent'Length elsif Is_Entity_Length (Right_Opnd (N)) and then Is_Optimizable (Left_Opnd (N)) then -- Flip comparison to opposite sense case Op is when N_Op_Lt => Op := N_Op_Gt; when N_Op_Le => Op := N_Op_Ge; when N_Op_Gt => Op := N_Op_Lt; when N_Op_Ge => Op := N_Op_Le; when others => null; end case; -- Else optimization not possible else return; end if; -- Fall through if we will do the optimization -- Cases to handle: -- X'Length = 0 => X'First > X'Last -- X'Length = 1 => X'First = X'Last -- X'Length = n => X'First + (n - 1) = X'Last -- X'Length /= 0 => X'First <= X'Last -- X'Length /= 1 => X'First /= X'Last -- X'Length /= n => X'First + (n - 1) /= X'Last -- X'Length >= 0 => always true, warn -- X'Length >= 1 => X'First <= X'Last -- X'Length >= n => X'First + (n - 1) <= X'Last -- X'Length > 0 => X'First <= X'Last -- X'Length > 1 => X'First < X'Last -- X'Length > n => X'First + (n - 1) < X'Last -- X'Length <= 0 => X'First > X'Last (warn, could be =) -- X'Length <= 1 => X'First >= X'Last -- X'Length <= n => X'First + (n - 1) >= X'Last -- X'Length < 0 => always false (warn) -- X'Length < 1 => X'First > X'Last -- X'Length < n => X'First + (n - 1) > X'Last -- Note: for the cases of n (not constant 0,1), we require that the -- corresponding index type be integer or shorter (i.e. not 64-bit), -- and the same for the comparison value. Then we do the comparison -- using 64-bit arithmetic (actually long long integer), so that we -- cannot have overflow intefering with the result. -- First deal with warning cases if Is_Zero then case Op is -- X'Length >= 0 when N_Op_Ge => Rewrite (N, Convert_To (Typ, New_Occurrence_Of (Standard_True, Loc))); Analyze_And_Resolve (N, Typ); Warn_On_Known_Condition (N); return; -- X'Length < 0 when N_Op_Lt => Rewrite (N, Convert_To (Typ, New_Occurrence_Of (Standard_False, Loc))); Analyze_And_Resolve (N, Typ); Warn_On_Known_Condition (N); return; when N_Op_Le => if Constant_Condition_Warnings and then Comes_From_Source (Original_Node (N)) then Error_Msg_N ("could replace by ""'=""?", N); end if; Op := N_Op_Eq; when others => null; end case; end if; -- Build the First reference we will use Left := Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Ent, Loc), Attribute_Name => Name_First); if Present (Index) then Set_Expressions (Left, New_List (New_Copy (Index))); end if; -- If general value case, then do the addition of (n - 1), and -- also add the needed conversions to type Long_Long_Integer. if Present (Comp) then Left := Make_Op_Add (Loc, Left_Opnd => Prepare_64 (Left), Right_Opnd => Make_Op_Subtract (Loc, Left_Opnd => Prepare_64 (Comp), Right_Opnd => Make_Integer_Literal (Loc, 1))); end if; -- Build the Last reference we will use Right := Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (Ent, Loc), Attribute_Name => Name_Last); if Present (Index) then Set_Expressions (Right, New_List (New_Copy (Index))); end if; -- If general operand, convert Last reference to Long_Long_Integer if Present (Comp) then Right := Prepare_64 (Right); end if; -- Check for cases to optimize -- X'Length = 0 => X'First > X'Last -- X'Length < 1 => X'First > X'Last -- X'Length < n => X'First + (n - 1) > X'Last if (Is_Zero and then Op = N_Op_Eq) or else (not Is_Zero and then Op = N_Op_Lt) then Result := Make_Op_Gt (Loc, Left_Opnd => Left, Right_Opnd => Right); -- X'Length = 1 => X'First = X'Last -- X'Length = n => X'First + (n - 1) = X'Last elsif not Is_Zero and then Op = N_Op_Eq then Result := Make_Op_Eq (Loc, Left_Opnd => Left, Right_Opnd => Right); -- X'Length /= 0 => X'First <= X'Last -- X'Length > 0 => X'First <= X'Last elsif Is_Zero and (Op = N_Op_Ne or else Op = N_Op_Gt) then Result := Make_Op_Le (Loc, Left_Opnd => Left, Right_Opnd => Right); -- X'Length /= 1 => X'First /= X'Last -- X'Length /= n => X'First + (n - 1) /= X'Last elsif not Is_Zero and then Op = N_Op_Ne then Result := Make_Op_Ne (Loc, Left_Opnd => Left, Right_Opnd => Right); -- X'Length >= 1 => X'First <= X'Last -- X'Length >= n => X'First + (n - 1) <= X'Last elsif not Is_Zero and then Op = N_Op_Ge then Result := Make_Op_Le (Loc, Left_Opnd => Left, Right_Opnd => Right); -- X'Length > 1 => X'First < X'Last -- X'Length > n => X'First + (n = 1) < X'Last elsif not Is_Zero and then Op = N_Op_Gt then Result := Make_Op_Lt (Loc, Left_Opnd => Left, Right_Opnd => Right); -- X'Length <= 1 => X'First >= X'Last -- X'Length <= n => X'First + (n - 1) >= X'Last elsif not Is_Zero and then Op = N_Op_Le then Result := Make_Op_Ge (Loc, Left_Opnd => Left, Right_Opnd => Right); -- Should not happen at this stage else raise Program_Error; end if; -- Rewrite and finish up Rewrite (N, Result); Analyze_And_Resolve (N, Typ); return; end Optimize_Length_Comparison; ------------------------ -- Rewrite_Comparison -- ------------------------ procedure Rewrite_Comparison (N : Node_Id) is Warning_Generated : Boolean := False; -- Set to True if first pass with Assume_Valid generates a warning in -- which case we skip the second pass to avoid warning overloaded. Result : Node_Id; -- Set to Standard_True or Standard_False begin if Nkind (N) = N_Type_Conversion then Rewrite_Comparison (Expression (N)); return; elsif Nkind (N) not in N_Op_Compare then return; end if; -- Now start looking at the comparison in detail. We potentially go -- through this loop twice. The first time, Assume_Valid is set False -- in the call to Compile_Time_Compare. If this call results in a -- clear result of always True or Always False, that's decisive and -- we are done. Otherwise we repeat the processing with Assume_Valid -- set to True to generate additional warnings. We can skip that step -- if Constant_Condition_Warnings is False. for AV in False .. True loop declare Typ : constant Entity_Id := Etype (N); Op1 : constant Node_Id := Left_Opnd (N); Op2 : constant Node_Id := Right_Opnd (N); Res : constant Compare_Result := Compile_Time_Compare (Op1, Op2, Assume_Valid => AV); -- Res indicates if compare outcome can be compile time determined True_Result : Boolean; False_Result : Boolean; begin case N_Op_Compare (Nkind (N)) is when N_Op_Eq => True_Result := Res = EQ; False_Result := Res = LT or else Res = GT or else Res = NE; when N_Op_Ge => True_Result := Res in Compare_GE; False_Result := Res = LT; if Res = LE and then Constant_Condition_Warnings and then Comes_From_Source (Original_Node (N)) and then Nkind (Original_Node (N)) = N_Op_Ge and then not In_Instance and then Is_Integer_Type (Etype (Left_Opnd (N))) and then not Has_Warnings_Off (Etype (Left_Opnd (N))) then Error_Msg_N ("can never be greater than, could replace by ""'=""?", N); Warning_Generated := True; end if; when N_Op_Gt => True_Result := Res = GT; False_Result := Res in Compare_LE; when N_Op_Lt => True_Result := Res = LT; False_Result := Res in Compare_GE; when N_Op_Le => True_Result := Res in Compare_LE; False_Result := Res = GT; if Res = GE and then Constant_Condition_Warnings and then Comes_From_Source (Original_Node (N)) and then Nkind (Original_Node (N)) = N_Op_Le and then not In_Instance and then Is_Integer_Type (Etype (Left_Opnd (N))) and then not Has_Warnings_Off (Etype (Left_Opnd (N))) then Error_Msg_N ("can never be less than, could replace by ""'=""?", N); Warning_Generated := True; end if; when N_Op_Ne => True_Result := Res = NE or else Res = GT or else Res = LT; False_Result := Res = EQ; end case; -- If this is the first iteration, then we actually convert the -- comparison into True or False, if the result is certain. if AV = False then if True_Result or False_Result then if True_Result then Result := Standard_True; else Result := Standard_False; end if; Rewrite (N, Convert_To (Typ, New_Occurrence_Of (Result, Sloc (N)))); Analyze_And_Resolve (N, Typ); Warn_On_Known_Condition (N); return; end if; -- If this is the second iteration (AV = True), and the original -- node comes from source and we are not in an instance, then give -- a warning if we know result would be True or False. Note: we -- know Constant_Condition_Warnings is set if we get here. elsif Comes_From_Source (Original_Node (N)) and then not In_Instance then if True_Result then Error_Msg_N ("condition can only be False if invalid values present?", N); elsif False_Result then Error_Msg_N ("condition can only be True if invalid values present?", N); end if; end if; end; -- Skip second iteration if not warning on constant conditions or -- if the first iteration already generated a warning of some kind or -- if we are in any case assuming all values are valid (so that the -- first iteration took care of the valid case). exit when not Constant_Condition_Warnings; exit when Warning_Generated; exit when Assume_No_Invalid_Values; end loop; end Rewrite_Comparison; ---------------------------- -- Safe_In_Place_Array_Op -- ---------------------------- function Safe_In_Place_Array_Op (Lhs : Node_Id; Op1 : Node_Id; Op2 : Node_Id) return Boolean is Target : Entity_Id; function Is_Safe_Operand (Op : Node_Id) return Boolean; -- Operand is safe if it cannot overlap part of the target of the -- operation. If the operand and the target are identical, the operand -- is safe. The operand can be empty in the case of negation. function Is_Unaliased (N : Node_Id) return Boolean; -- Check that N is a stand-alone entity ------------------ -- Is_Unaliased -- ------------------ function Is_Unaliased (N : Node_Id) return Boolean is begin return Is_Entity_Name (N) and then No (Address_Clause (Entity (N))) and then No (Renamed_Object (Entity (N))); end Is_Unaliased; --------------------- -- Is_Safe_Operand -- --------------------- function Is_Safe_Operand (Op : Node_Id) return Boolean is begin if No (Op) then return True; elsif Is_Entity_Name (Op) then return Is_Unaliased (Op); elsif Nkind_In (Op, N_Indexed_Component, N_Selected_Component) then return Is_Unaliased (Prefix (Op)); elsif Nkind (Op) = N_Slice then return Is_Unaliased (Prefix (Op)) and then Entity (Prefix (Op)) /= Target; elsif Nkind (Op) = N_Op_Not then return Is_Safe_Operand (Right_Opnd (Op)); else return False; end if; end Is_Safe_Operand; -- Start of processing for Is_Safe_In_Place_Array_Op begin -- Skip this processing if the component size is different from system -- storage unit (since at least for NOT this would cause problems). if Component_Size (Etype (Lhs)) /= System_Storage_Unit then return False; -- Cannot do in place stuff on VM_Target since cannot pass addresses elsif VM_Target /= No_VM then return False; -- Cannot do in place stuff if non-standard Boolean representation elsif Has_Non_Standard_Rep (Component_Type (Etype (Lhs))) then return False; elsif not Is_Unaliased (Lhs) then return False; else Target := Entity (Lhs); return Is_Safe_Operand (Op1) and then Is_Safe_Operand (Op2); end if; end Safe_In_Place_Array_Op; ----------------------- -- Tagged_Membership -- ----------------------- -- There are two different cases to consider depending on whether the right -- operand is a class-wide type or not. If not we just compare the actual -- tag of the left expr to the target type tag: -- -- Left_Expr.Tag = Right_Type'Tag; -- -- If it is a class-wide type we use the RT function CW_Membership which is -- usually implemented by looking in the ancestor tables contained in the -- dispatch table pointed by Left_Expr.Tag for Typ'Tag -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT -- function IW_Membership which is usually implemented by looking in the -- table of abstract interface types plus the ancestor table contained in -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag procedure Tagged_Membership (N : Node_Id; SCIL_Node : out Node_Id; Result : out Node_Id) is Left : constant Node_Id := Left_Opnd (N); Right : constant Node_Id := Right_Opnd (N); Loc : constant Source_Ptr := Sloc (N); Full_R_Typ : Entity_Id; Left_Type : Entity_Id; New_Node : Node_Id; Right_Type : Entity_Id; Obj_Tag : Node_Id; begin SCIL_Node := Empty; -- Handle entities from the limited view Left_Type := Available_View (Etype (Left)); Right_Type := Available_View (Etype (Right)); -- In the case where the type is an access type, the test is applied -- using the designated types (needed in Ada 2012 for implicit anonymous -- access conversions, for AI05-0149). if Is_Access_Type (Right_Type) then Left_Type := Designated_Type (Left_Type); Right_Type := Designated_Type (Right_Type); end if; if Is_Class_Wide_Type (Left_Type) then Left_Type := Root_Type (Left_Type); end if; if Is_Class_Wide_Type (Right_Type) then Full_R_Typ := Underlying_Type (Root_Type (Right_Type)); else Full_R_Typ := Underlying_Type (Right_Type); end if; Obj_Tag := Make_Selected_Component (Loc, Prefix => Relocate_Node (Left), Selector_Name => New_Reference_To (First_Tag_Component (Left_Type), Loc)); if Is_Class_Wide_Type (Right_Type) then -- No need to issue a run-time check if we statically know that the -- result of this membership test is always true. For example, -- considering the following declarations: -- type Iface is interface; -- type T is tagged null record; -- type DT is new T and Iface with null record; -- Obj1 : T; -- Obj2 : DT; -- These membership tests are always true: -- Obj1 in T'Class -- Obj2 in T'Class; -- Obj2 in Iface'Class; -- We do not need to handle cases where the membership is illegal. -- For example: -- Obj1 in DT'Class; -- Compile time error -- Obj1 in Iface'Class; -- Compile time error if not Is_Class_Wide_Type (Left_Type) and then (Is_Ancestor (Etype (Right_Type), Left_Type, Use_Full_View => True) or else (Is_Interface (Etype (Right_Type)) and then Interface_Present_In_Ancestor (Typ => Left_Type, Iface => Etype (Right_Type)))) then Result := New_Reference_To (Standard_True, Loc); return; end if; -- Ada 2005 (AI-251): Class-wide applied to interfaces if Is_Interface (Etype (Class_Wide_Type (Right_Type))) -- Support to: "Iface_CW_Typ in Typ'Class" or else Is_Interface (Left_Type) then -- Issue error if IW_Membership operation not available in a -- configurable run time setting. if not RTE_Available (RE_IW_Membership) then Error_Msg_CRT ("dynamic membership test on interface types", N); Result := Empty; return; end if; Result := Make_Function_Call (Loc, Name => New_Occurrence_Of (RTE (RE_IW_Membership), Loc), Parameter_Associations => New_List ( Make_Attribute_Reference (Loc, Prefix => Obj_Tag, Attribute_Name => Name_Address), New_Reference_To ( Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc))); -- Ada 95: Normal case else Build_CW_Membership (Loc, Obj_Tag_Node => Obj_Tag, Typ_Tag_Node => New_Reference_To ( Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc), Related_Nod => N, New_Node => New_Node); -- Generate the SCIL node for this class-wide membership test. -- Done here because the previous call to Build_CW_Membership -- relocates Obj_Tag. if Generate_SCIL then SCIL_Node := Make_SCIL_Membership_Test (Sloc (N)); Set_SCIL_Entity (SCIL_Node, Etype (Right_Type)); Set_SCIL_Tag_Value (SCIL_Node, Obj_Tag); end if; Result := New_Node; end if; -- Right_Type is not a class-wide type else -- No need to check the tag of the object if Right_Typ is abstract if Is_Abstract_Type (Right_Type) then Result := New_Reference_To (Standard_False, Loc); else Result := Make_Op_Eq (Loc, Left_Opnd => Obj_Tag, Right_Opnd => New_Reference_To (Node (First_Elmt (Access_Disp_Table (Full_R_Typ))), Loc)); end if; end if; end Tagged_Membership; ------------------------------ -- Unary_Op_Validity_Checks -- ------------------------------ procedure Unary_Op_Validity_Checks (N : Node_Id) is begin if Validity_Checks_On and Validity_Check_Operands then Ensure_Valid (Right_Opnd (N)); end if; end Unary_Op_Validity_Checks; end Exp_Ch4;
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