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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E X P _ U T I L -- -- -- -- 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 Aspects; use Aspects; with Atree; use Atree; with Casing; use Casing; 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_Ch6; use Exp_Ch6; with Exp_Ch7; use Exp_Ch7; with Inline; use Inline; with Itypes; use Itypes; with Lib; use Lib; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Restrict; use Restrict; with Rident; use Rident; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Ch8; use Sem_Ch8; with Sem_Eval; use Sem_Eval; with Sem_Prag; use Sem_Prag; with Sem_Res; use Sem_Res; with Sem_Type; use Sem_Type; with Sem_Util; use Sem_Util; with Snames; use Snames; with Stand; use Stand; with Stringt; use Stringt; with Targparm; use Targparm; with Tbuild; use Tbuild; with Ttypes; use Ttypes; with Urealp; use Urealp; with Validsw; use Validsw; package body Exp_Util is ----------------------- -- Local Subprograms -- ----------------------- function Build_Task_Array_Image (Loc : Source_Ptr; Id_Ref : Node_Id; A_Type : Entity_Id; Dyn : Boolean := False) return Node_Id; -- Build function to generate the image string for a task that is an array -- component, concatenating the images of each index. To avoid storage -- leaks, the string is built with successive slice assignments. The flag -- Dyn indicates whether this is called for the initialization procedure of -- an array of tasks, or for the name of a dynamically created task that is -- assigned to an indexed component. function Build_Task_Image_Function (Loc : Source_Ptr; Decls : List_Id; Stats : List_Id; Res : Entity_Id) return Node_Id; -- Common processing for Task_Array_Image and Task_Record_Image. Build -- function body that computes image. procedure Build_Task_Image_Prefix (Loc : Source_Ptr; Len : out Entity_Id; Res : out Entity_Id; Pos : out Entity_Id; Prefix : Entity_Id; Sum : Node_Id; Decls : List_Id; Stats : List_Id); -- Common processing for Task_Array_Image and Task_Record_Image. Create -- local variables and assign prefix of name to result string. function Build_Task_Record_Image (Loc : Source_Ptr; Id_Ref : Node_Id; Dyn : Boolean := False) return Node_Id; -- Build function to generate the image string for a task that is a record -- component. Concatenate name of variable with that of selector. The flag -- Dyn indicates whether this is called for the initialization procedure of -- record with task components, or for a dynamically created task that is -- assigned to a selected component. function Make_CW_Equivalent_Type (T : Entity_Id; E : Node_Id) return Entity_Id; -- T is a class-wide type entity, E is the initial expression node that -- constrains T in case such as: " X: T := E" or "new T'(E)". This function -- returns the entity of the Equivalent type and inserts on the fly the -- necessary declaration such as: -- -- type anon is record -- _parent : Root_Type (T); constrained with E discriminants (if any) -- Extension : String (1 .. expr to match size of E); -- end record; -- -- This record is compatible with any object of the class of T thanks to -- the first field and has the same size as E thanks to the second. function Make_Literal_Range (Loc : Source_Ptr; Literal_Typ : Entity_Id) return Node_Id; -- Produce a Range node whose bounds are: -- Low_Bound (Literal_Type) .. -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1) -- this is used for expanding declarations like X : String := "sdfgdfg"; -- -- If the index type of the target array is not integer, we generate: -- Low_Bound (Literal_Type) .. -- Literal_Type'Val -- (Literal_Type'Pos (Low_Bound (Literal_Type)) -- + (Length (Literal_Typ) -1)) function Make_Non_Empty_Check (Loc : Source_Ptr; N : Node_Id) return Node_Id; -- Produce a boolean expression checking that the unidimensional array -- node N is not empty. function New_Class_Wide_Subtype (CW_Typ : Entity_Id; N : Node_Id) return Entity_Id; -- Create an implicit subtype of CW_Typ attached to node N function Requires_Cleanup_Actions (L : List_Id; For_Package : Boolean; Nested_Constructs : Boolean) return Boolean; -- Given a list L, determine whether it contains one of the following: -- -- 1) controlled objects -- 2) library-level tagged types -- -- Flag For_Package should be set when the list comes from a package spec -- or body. Flag Nested_Constructs should be set when any nested packages -- declared in L must be processed. ------------------------------------- -- Activate_Atomic_Synchronization -- ------------------------------------- procedure Activate_Atomic_Synchronization (N : Node_Id) is Msg_Node : Node_Id; begin case Nkind (Parent (N)) is -- Check for cases of appearing in the prefix of a construct where -- we don't need atomic synchronization for this kind of usage. when -- Nothing to do if we are the prefix of an attribute, since we -- do not want an atomic sync operation for things like 'Size. N_Attribute_Reference | -- The N_Reference node is like an attribute N_Reference | -- Nothing to do for a reference to a component (or components) -- of a composite object. Only reads and updates of the object -- as a whole require atomic synchronization (RM C.6 (15)). N_Indexed_Component | N_Selected_Component | N_Slice => -- For all the above cases, nothing to do if we are the prefix if Prefix (Parent (N)) = N then return; end if; when others => null; end case; -- Go ahead and set the flag Set_Atomic_Sync_Required (N); -- Generate info message if requested if Warn_On_Atomic_Synchronization then case Nkind (N) is when N_Identifier => Msg_Node := N; when N_Selected_Component | N_Expanded_Name => Msg_Node := Selector_Name (N); when N_Explicit_Dereference | N_Indexed_Component => Msg_Node := Empty; when others => pragma Assert (False); return; end case; if Present (Msg_Node) then Error_Msg_N ("?info: atomic synchronization set for &", Msg_Node); else Error_Msg_N ("?info: atomic synchronization set", N); end if; end if; end Activate_Atomic_Synchronization; ---------------------- -- Adjust_Condition -- ---------------------- procedure Adjust_Condition (N : Node_Id) is begin if No (N) then return; end if; declare Loc : constant Source_Ptr := Sloc (N); T : constant Entity_Id := Etype (N); Ti : Entity_Id; begin -- Defend against a call where the argument has no type, or has a -- type that is not Boolean. This can occur because of prior errors. if No (T) or else not Is_Boolean_Type (T) then return; end if; -- Apply validity checking if needed if Validity_Checks_On and Validity_Check_Tests then Ensure_Valid (N); end if; -- Immediate return if standard boolean, the most common case, -- where nothing needs to be done. if Base_Type (T) = Standard_Boolean then return; end if; -- Case of zero/non-zero semantics or non-standard enumeration -- representation. In each case, we rewrite the node as: -- ityp!(N) /= False'Enum_Rep -- where ityp is an integer type with large enough size to hold any -- value of type T. if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then if Esize (T) <= Esize (Standard_Integer) then Ti := Standard_Integer; else Ti := Standard_Long_Long_Integer; end if; Rewrite (N, Make_Op_Ne (Loc, Left_Opnd => Unchecked_Convert_To (Ti, N), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Enum_Rep, Prefix => New_Occurrence_Of (First_Literal (T), Loc)))); Analyze_And_Resolve (N, Standard_Boolean); else Rewrite (N, Convert_To (Standard_Boolean, N)); Analyze_And_Resolve (N, Standard_Boolean); end if; end; end Adjust_Condition; ------------------------ -- Adjust_Result_Type -- ------------------------ procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is begin -- Ignore call if current type is not Standard.Boolean if Etype (N) /= Standard_Boolean then return; end if; -- If result is already of correct type, nothing to do. Note that -- this will get the most common case where everything has a type -- of Standard.Boolean. if Base_Type (T) = Standard_Boolean then return; else declare KP : constant Node_Kind := Nkind (Parent (N)); begin -- If result is to be used as a Condition in the syntax, no need -- to convert it back, since if it was changed to Standard.Boolean -- using Adjust_Condition, that is just fine for this usage. if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then return; -- If result is an operand of another logical operation, no need -- to reset its type, since Standard.Boolean is just fine, and -- such operations always do Adjust_Condition on their operands. elsif KP in N_Op_Boolean or else KP in N_Short_Circuit or else KP = N_Op_Not then return; -- Otherwise we perform a conversion from the current type, which -- must be Standard.Boolean, to the desired type. else Set_Analyzed (N); Rewrite (N, Convert_To (T, N)); Analyze_And_Resolve (N, T); end if; end; end if; end Adjust_Result_Type; -------------------------- -- Append_Freeze_Action -- -------------------------- procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is Fnode : Node_Id; begin Ensure_Freeze_Node (T); Fnode := Freeze_Node (T); if No (Actions (Fnode)) then Set_Actions (Fnode, New_List); end if; Append (N, Actions (Fnode)); end Append_Freeze_Action; --------------------------- -- Append_Freeze_Actions -- --------------------------- procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is Fnode : constant Node_Id := Freeze_Node (T); begin if No (L) then return; else if No (Actions (Fnode)) then Set_Actions (Fnode, L); else Append_List (L, Actions (Fnode)); end if; end if; end Append_Freeze_Actions; ------------------------------------ -- Build_Allocate_Deallocate_Proc -- ------------------------------------ procedure Build_Allocate_Deallocate_Proc (N : Node_Id; Is_Allocate : Boolean) is Desig_Typ : Entity_Id; Expr : Node_Id; Pool_Id : Entity_Id; Proc_To_Call : Node_Id := Empty; Ptr_Typ : Entity_Id; function Find_Finalize_Address (Typ : Entity_Id) return Entity_Id; -- Locate TSS primitive Finalize_Address in type Typ function Find_Object (E : Node_Id) return Node_Id; -- Given an arbitrary expression of an allocator, try to find an object -- reference in it, otherwise return the original expression. function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean; -- Determine whether subprogram Subp denotes a custom allocate or -- deallocate. --------------------------- -- Find_Finalize_Address -- --------------------------- function Find_Finalize_Address (Typ : Entity_Id) return Entity_Id is Utyp : Entity_Id := Typ; begin -- Handle protected class-wide or task class-wide types if Is_Class_Wide_Type (Utyp) then if Is_Concurrent_Type (Root_Type (Utyp)) then Utyp := Root_Type (Utyp); elsif Is_Private_Type (Root_Type (Utyp)) and then Present (Full_View (Root_Type (Utyp))) and then Is_Concurrent_Type (Full_View (Root_Type (Utyp))) then Utyp := Full_View (Root_Type (Utyp)); end if; end if; -- Handle private types if Is_Private_Type (Utyp) and then Present (Full_View (Utyp)) then Utyp := Full_View (Utyp); end if; -- Handle protected and task types if Is_Concurrent_Type (Utyp) and then Present (Corresponding_Record_Type (Utyp)) then Utyp := Corresponding_Record_Type (Utyp); end if; Utyp := Underlying_Type (Base_Type (Utyp)); -- Deal with non-tagged derivation of private views. If the parent is -- now known to be protected, the finalization routine is the one -- defined on the corresponding record of the ancestor (corresponding -- records do not automatically inherit operations, but maybe they -- should???) if Is_Untagged_Derivation (Typ) then if Is_Protected_Type (Typ) then Utyp := Corresponding_Record_Type (Root_Type (Base_Type (Typ))); else Utyp := Underlying_Type (Root_Type (Base_Type (Typ))); if Is_Protected_Type (Utyp) then Utyp := Corresponding_Record_Type (Utyp); end if; end if; end if; -- If the underlying_type is a subtype, we are dealing with the -- completion of a private type. We need to access the base type and -- generate a conversion to it. if Utyp /= Base_Type (Utyp) then pragma Assert (Is_Private_Type (Typ)); Utyp := Base_Type (Utyp); end if; -- When dealing with an internally built full view for a type with -- unknown discriminants, use the original record type. if Is_Underlying_Record_View (Utyp) then Utyp := Etype (Utyp); end if; return TSS (Utyp, TSS_Finalize_Address); end Find_Finalize_Address; ----------------- -- Find_Object -- ----------------- function Find_Object (E : Node_Id) return Node_Id is Expr : Node_Id; begin pragma Assert (Is_Allocate); Expr := E; loop if Nkind_In (Expr, N_Qualified_Expression, N_Unchecked_Type_Conversion) then Expr := Expression (Expr); elsif Nkind (Expr) = N_Explicit_Dereference then Expr := Prefix (Expr); else exit; end if; end loop; return Expr; end Find_Object; --------------------------------- -- Is_Allocate_Deallocate_Proc -- --------------------------------- function Is_Allocate_Deallocate_Proc (Subp : Entity_Id) return Boolean is begin -- Look for a subprogram body with only one statement which is a -- call to Allocate_Any_Controlled / Deallocate_Any_Controlled. if Ekind (Subp) = E_Procedure and then Nkind (Parent (Parent (Subp))) = N_Subprogram_Body then declare HSS : constant Node_Id := Handled_Statement_Sequence (Parent (Parent (Subp))); Proc : Entity_Id; begin if Present (Statements (HSS)) and then Nkind (First (Statements (HSS))) = N_Procedure_Call_Statement then Proc := Entity (Name (First (Statements (HSS)))); return Is_RTE (Proc, RE_Allocate_Any_Controlled) or else Is_RTE (Proc, RE_Deallocate_Any_Controlled); end if; end; end if; return False; end Is_Allocate_Deallocate_Proc; -- Start of processing for Build_Allocate_Deallocate_Proc begin -- Do not perform this expansion in Alfa mode because it is not -- necessary. if Alfa_Mode then return; end if; -- Obtain the attributes of the allocation / deallocation if Nkind (N) = N_Free_Statement then Expr := Expression (N); Ptr_Typ := Base_Type (Etype (Expr)); Proc_To_Call := Procedure_To_Call (N); else if Nkind (N) = N_Object_Declaration then Expr := Expression (N); else Expr := N; end if; -- In certain cases an allocator with a qualified expression may -- be relocated and used as the initialization expression of a -- temporary: -- before: -- Obj : Ptr_Typ := new Desig_Typ'(...); -- after: -- Tmp : Ptr_Typ := new Desig_Typ'(...); -- Obj : Ptr_Typ := Tmp; -- Since the allocator is always marked as analyzed to avoid infinite -- expansion, it will never be processed by this routine given that -- the designated type needs finalization actions. Detect this case -- and complete the expansion of the allocator. if Nkind (Expr) = N_Identifier and then Nkind (Parent (Entity (Expr))) = N_Object_Declaration and then Nkind (Expression (Parent (Entity (Expr)))) = N_Allocator then Build_Allocate_Deallocate_Proc (Parent (Entity (Expr)), True); return; end if; -- The allocator may have been rewritten into something else in which -- case the expansion performed by this routine does not apply. if Nkind (Expr) /= N_Allocator then return; end if; Ptr_Typ := Base_Type (Etype (Expr)); Proc_To_Call := Procedure_To_Call (Expr); end if; Pool_Id := Associated_Storage_Pool (Ptr_Typ); Desig_Typ := Available_View (Designated_Type (Ptr_Typ)); -- Handle concurrent types if Is_Concurrent_Type (Desig_Typ) and then Present (Corresponding_Record_Type (Desig_Typ)) then Desig_Typ := Corresponding_Record_Type (Desig_Typ); end if; -- Do not process allocations / deallocations without a pool if No (Pool_Id) then return; -- Do not process allocations on / deallocations from the secondary -- stack. elsif Is_RTE (Pool_Id, RE_SS_Pool) then return; -- Do not replicate the machinery if the allocator / free has already -- been expanded and has a custom Allocate / Deallocate. elsif Present (Proc_To_Call) and then Is_Allocate_Deallocate_Proc (Proc_To_Call) then return; end if; if Needs_Finalization (Desig_Typ) then -- Certain run-time configurations and targets do not provide support -- for controlled types. if Restriction_Active (No_Finalization) then return; -- Do nothing if the access type may never allocate / deallocate -- objects. elsif No_Pool_Assigned (Ptr_Typ) then return; -- Access-to-controlled types are not supported on .NET/JVM since -- these targets cannot support pools and address arithmetic. elsif VM_Target /= No_VM then return; end if; -- The allocation / deallocation of a controlled object must be -- chained on / detached from a finalization master. pragma Assert (Present (Finalization_Master (Ptr_Typ))); -- The only other kind of allocation / deallocation supported by this -- routine is on / from a subpool. elsif Nkind (Expr) = N_Allocator and then No (Subpool_Handle_Name (Expr)) then return; end if; declare Loc : constant Source_Ptr := Sloc (N); Addr_Id : constant Entity_Id := Make_Temporary (Loc, 'A'); Alig_Id : constant Entity_Id := Make_Temporary (Loc, 'L'); Proc_Id : constant Entity_Id := Make_Temporary (Loc, 'P'); Size_Id : constant Entity_Id := Make_Temporary (Loc, 'S'); Actuals : List_Id; Fin_Addr_Id : Entity_Id; Fin_Mas_Act : Node_Id; Fin_Mas_Id : Entity_Id; Proc_To_Call : Entity_Id; Subpool : Node_Id := Empty; begin -- Step 1: Construct all the actuals for the call to library routine -- Allocate_Any_Controlled / Deallocate_Any_Controlled. -- a) Storage pool Actuals := New_List (New_Reference_To (Pool_Id, Loc)); if Is_Allocate then -- b) Subpool if Nkind (Expr) = N_Allocator then Subpool := Subpool_Handle_Name (Expr); end if; if Present (Subpool) then Append_To (Actuals, New_Reference_To (Entity (Subpool), Loc)); else Append_To (Actuals, Make_Null (Loc)); end if; -- c) Finalization master if Needs_Finalization (Desig_Typ) then Fin_Mas_Id := Finalization_Master (Ptr_Typ); Fin_Mas_Act := New_Reference_To (Fin_Mas_Id, Loc); -- Handle the case where the master is actually a pointer to a -- master. This case arises in build-in-place functions. if Is_Access_Type (Etype (Fin_Mas_Id)) then Append_To (Actuals, Fin_Mas_Act); else Append_To (Actuals, Make_Attribute_Reference (Loc, Prefix => Fin_Mas_Act, Attribute_Name => Name_Unrestricted_Access)); end if; else Append_To (Actuals, Make_Null (Loc)); end if; -- d) Finalize_Address -- Primitive Finalize_Address is never generated in CodePeer mode -- since it contains an Unchecked_Conversion. if Needs_Finalization (Desig_Typ) and then not CodePeer_Mode then Fin_Addr_Id := Find_Finalize_Address (Desig_Typ); pragma Assert (Present (Fin_Addr_Id)); Append_To (Actuals, Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Fin_Addr_Id, Loc), Attribute_Name => Name_Unrestricted_Access)); else Append_To (Actuals, Make_Null (Loc)); end if; end if; -- e) Address -- f) Storage_Size -- g) Alignment Append_To (Actuals, New_Reference_To (Addr_Id, Loc)); Append_To (Actuals, New_Reference_To (Size_Id, Loc)); if Is_Allocate or else not Is_Class_Wide_Type (Desig_Typ) then Append_To (Actuals, New_Reference_To (Alig_Id, Loc)); -- For deallocation of class wide types we obtain the value of -- alignment from the Type Specific Record of the deallocated object. -- This is needed because the frontend expansion of class-wide types -- into equivalent types confuses the backend. else -- Generate: -- Obj.all'Alignment -- ... because 'Alignment applied to class-wide types is expanded -- into the code that reads the value of alignment from the TSD -- (see Expand_N_Attribute_Reference) Append_To (Actuals, Unchecked_Convert_To (RTE (RE_Storage_Offset), Make_Attribute_Reference (Loc, Prefix => Make_Explicit_Dereference (Loc, Relocate_Node (Expr)), Attribute_Name => Name_Alignment))); end if; -- h) Is_Controlled -- Generate a run-time check to determine whether a class-wide object -- is truly controlled. if Needs_Finalization (Desig_Typ) then if Is_Class_Wide_Type (Desig_Typ) or else Is_Generic_Actual_Type (Desig_Typ) then declare Flag_Id : constant Entity_Id := Make_Temporary (Loc, 'F'); Flag_Expr : Node_Id; Param : Node_Id; Temp : Node_Id; begin if Is_Allocate then Temp := Find_Object (Expression (Expr)); else Temp := Expr; end if; -- Processing for generic actuals if Is_Generic_Actual_Type (Desig_Typ) then Flag_Expr := New_Reference_To (Boolean_Literals (Needs_Finalization (Base_Type (Desig_Typ))), Loc); -- Processing for subtype indications elsif Nkind (Temp) in N_Has_Entity and then Is_Type (Entity (Temp)) then Flag_Expr := New_Reference_To (Boolean_Literals (Needs_Finalization (Entity (Temp))), Loc); -- Generate a runtime check to test the controlled state of -- an object for the purposes of allocation / deallocation. else -- The following case arises when allocating through an -- interface class-wide type, generate: -- -- Temp.all if Is_RTE (Etype (Temp), RE_Tag_Ptr) then Param := Make_Explicit_Dereference (Loc, Prefix => Relocate_Node (Temp)); -- Generate: -- Temp'Tag else Param := Make_Attribute_Reference (Loc, Prefix => Relocate_Node (Temp), Attribute_Name => Name_Tag); end if; -- Generate: -- Needs_Finalization (<Param>) Flag_Expr := Make_Function_Call (Loc, Name => New_Reference_To (RTE (RE_Needs_Finalization), Loc), Parameter_Associations => New_List (Param)); end if; -- Create the temporary which represents the finalization -- state of the expression. Generate: -- -- F : constant Boolean := <Flag_Expr>; Insert_Action (N, Make_Object_Declaration (Loc, Defining_Identifier => Flag_Id, Constant_Present => True, Object_Definition => New_Reference_To (Standard_Boolean, Loc), Expression => Flag_Expr)); -- The flag acts as the last actual Append_To (Actuals, New_Reference_To (Flag_Id, Loc)); end; -- The object is statically known to be controlled else Append_To (Actuals, New_Reference_To (Standard_True, Loc)); end if; else Append_To (Actuals, New_Reference_To (Standard_False, Loc)); end if; -- i) On_Subpool if Is_Allocate then Append_To (Actuals, New_Reference_To (Boolean_Literals (Present (Subpool)), Loc)); end if; -- Step 2: Build a wrapper Allocate / Deallocate which internally -- calls Allocate_Any_Controlled / Deallocate_Any_Controlled. -- Select the proper routine to call if Is_Allocate then Proc_To_Call := RTE (RE_Allocate_Any_Controlled); else Proc_To_Call := RTE (RE_Deallocate_Any_Controlled); end if; -- Create a custom Allocate / Deallocate routine which has identical -- profile to that of System.Storage_Pools. Insert_Action (N, Make_Subprogram_Body (Loc, Specification => -- procedure Pnn Make_Procedure_Specification (Loc, Defining_Unit_Name => Proc_Id, Parameter_Specifications => New_List ( -- P : Root_Storage_Pool Make_Parameter_Specification (Loc, Defining_Identifier => Make_Temporary (Loc, 'P'), Parameter_Type => New_Reference_To (RTE (RE_Root_Storage_Pool), Loc)), -- A : [out] Address Make_Parameter_Specification (Loc, Defining_Identifier => Addr_Id, Out_Present => Is_Allocate, Parameter_Type => New_Reference_To (RTE (RE_Address), Loc)), -- S : Storage_Count Make_Parameter_Specification (Loc, Defining_Identifier => Size_Id, Parameter_Type => New_Reference_To (RTE (RE_Storage_Count), Loc)), -- L : Storage_Count Make_Parameter_Specification (Loc, Defining_Identifier => Alig_Id, Parameter_Type => New_Reference_To (RTE (RE_Storage_Count), Loc)))), Declarations => No_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List ( Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc_To_Call, Loc), Parameter_Associations => Actuals))))); -- The newly generated Allocate / Deallocate becomes the default -- procedure to call when the back end processes the allocation / -- deallocation. if Is_Allocate then Set_Procedure_To_Call (Expr, Proc_Id); else Set_Procedure_To_Call (N, Proc_Id); end if; end; end Build_Allocate_Deallocate_Proc; ------------------------ -- Build_Runtime_Call -- ------------------------ function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is begin -- If entity is not available, we can skip making the call (this avoids -- junk duplicated error messages in a number of cases). if not RTE_Available (RE) then return Make_Null_Statement (Loc); else return Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE), Loc)); end if; end Build_Runtime_Call; ---------------------------- -- Build_Task_Array_Image -- ---------------------------- -- This function generates the body for a function that constructs the -- image string for a task that is an array component. The function is -- local to the init proc for the array type, and is called for each one -- of the components. The constructed image has the form of an indexed -- component, whose prefix is the outer variable of the array type. -- The n-dimensional array type has known indexes Index, Index2... -- Id_Ref is an indexed component form created by the enclosing init proc. -- Its successive indexes are Val1, Val2, ... which are the loop variables -- in the loops that call the individual task init proc on each component. -- The generated function has the following structure: -- function F return String is -- Pref : string renames Task_Name; -- T1 : String := Index1'Image (Val1); -- ... -- Tn : String := indexn'image (Valn); -- Len : Integer := T1'Length + ... + Tn'Length + n + 1; -- -- Len includes commas and the end parentheses. -- Res : String (1..Len); -- Pos : Integer := Pref'Length; -- -- begin -- Res (1 .. Pos) := Pref; -- Pos := Pos + 1; -- Res (Pos) := '('; -- Pos := Pos + 1; -- Res (Pos .. Pos + T1'Length - 1) := T1; -- Pos := Pos + T1'Length; -- Res (Pos) := '.'; -- Pos := Pos + 1; -- ... -- Res (Pos .. Pos + Tn'Length - 1) := Tn; -- Res (Len) := ')'; -- -- return Res; -- end F; -- -- Needless to say, multidimensional arrays of tasks are rare enough that -- the bulkiness of this code is not really a concern. function Build_Task_Array_Image (Loc : Source_Ptr; Id_Ref : Node_Id; A_Type : Entity_Id; Dyn : Boolean := False) return Node_Id is Dims : constant Nat := Number_Dimensions (A_Type); -- Number of dimensions for array of tasks Temps : array (1 .. Dims) of Entity_Id; -- Array of temporaries to hold string for each index Indx : Node_Id; -- Index expression Len : Entity_Id; -- Total length of generated name Pos : Entity_Id; -- Running index for substring assignments Pref : constant Entity_Id := Make_Temporary (Loc, 'P'); -- Name of enclosing variable, prefix of resulting name Res : Entity_Id; -- String to hold result Val : Node_Id; -- Value of successive indexes Sum : Node_Id; -- Expression to compute total size of string T : Entity_Id; -- Entity for name at one index position Decls : constant List_Id := New_List; Stats : constant List_Id := New_List; begin -- For a dynamic task, the name comes from the target variable. For a -- static one it is a formal of the enclosing init proc. if Dyn then Get_Name_String (Chars (Entity (Prefix (Id_Ref)))); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Pref, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); else Append_To (Decls, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Pref, Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), Name => Make_Identifier (Loc, Name_uTask_Name))); end if; Indx := First_Index (A_Type); Val := First (Expressions (Id_Ref)); for J in 1 .. Dims loop T := Make_Temporary (Loc, 'T'); Temps (J) := T; Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => T, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_Attribute_Reference (Loc, Attribute_Name => Name_Image, Prefix => New_Occurrence_Of (Etype (Indx), Loc), Expressions => New_List (New_Copy_Tree (Val))))); Next_Index (Indx); Next (Val); end loop; Sum := Make_Integer_Literal (Loc, Dims + 1); Sum := Make_Op_Add (Loc, Left_Opnd => Sum, Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Pref, Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))); for J in 1 .. Dims loop Sum := Make_Op_Add (Loc, Left_Opnd => Sum, Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Temps (J), Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))); end loop; Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats); Set_Character_Literal_Name (Char_Code (Character'Pos ('('))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Pos, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos ('('))))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); for J in 1 .. Dims loop Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Res, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => New_Occurrence_Of (Pos, Loc), High_Bound => Make_Op_Subtract (Loc, Left_Opnd => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Temps (J), Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))), Right_Opnd => Make_Integer_Literal (Loc, 1)))), Expression => New_Occurrence_Of (Temps (J), Loc))); if J < Dims then Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Temps (J), Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))))); Set_Character_Literal_Name (Char_Code (Character'Pos (','))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Pos, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos (','))))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); end if; end loop; Set_Character_Literal_Name (Char_Code (Character'Pos (')'))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Len, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos (')'))))); return Build_Task_Image_Function (Loc, Decls, Stats, Res); end Build_Task_Array_Image; ---------------------------- -- Build_Task_Image_Decls -- ---------------------------- function Build_Task_Image_Decls (Loc : Source_Ptr; Id_Ref : Node_Id; A_Type : Entity_Id; In_Init_Proc : Boolean := False) return List_Id is Decls : constant List_Id := New_List; T_Id : Entity_Id := Empty; Decl : Node_Id; Expr : Node_Id := Empty; Fun : Node_Id := Empty; Is_Dyn : constant Boolean := Nkind (Parent (Id_Ref)) = N_Assignment_Statement and then Nkind (Expression (Parent (Id_Ref))) = N_Allocator; begin -- If Discard_Names or No_Implicit_Heap_Allocations are in effect, -- generate a dummy declaration only. if Restriction_Active (No_Implicit_Heap_Allocations) or else Global_Discard_Names then T_Id := Make_Temporary (Loc, 'J'); Name_Len := 0; return New_List ( Make_Object_Declaration (Loc, Defining_Identifier => T_Id, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); else if Nkind (Id_Ref) = N_Identifier or else Nkind (Id_Ref) = N_Defining_Identifier then -- For a simple variable, the image of the task is built from -- the name of the variable. To avoid possible conflict with the -- anonymous type created for a single protected object, add a -- numeric suffix. T_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (Id_Ref), 'T', 1)); Get_Name_String (Chars (Id_Ref)); Expr := Make_String_Literal (Loc, Strval => String_From_Name_Buffer); elsif Nkind (Id_Ref) = N_Selected_Component then T_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (Selector_Name (Id_Ref)), 'T')); Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn); elsif Nkind (Id_Ref) = N_Indexed_Component then T_Id := Make_Defining_Identifier (Loc, New_External_Name (Chars (A_Type), 'N')); Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn); end if; end if; if Present (Fun) then Append (Fun, Decls); Expr := Make_Function_Call (Loc, Name => New_Occurrence_Of (Defining_Entity (Fun), Loc)); if not In_Init_Proc and then VM_Target = No_VM then Set_Uses_Sec_Stack (Defining_Entity (Fun)); end if; end if; Decl := Make_Object_Declaration (Loc, Defining_Identifier => T_Id, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Constant_Present => True, Expression => Expr); Append (Decl, Decls); return Decls; end Build_Task_Image_Decls; ------------------------------- -- Build_Task_Image_Function -- ------------------------------- function Build_Task_Image_Function (Loc : Source_Ptr; Decls : List_Id; Stats : List_Id; Res : Entity_Id) return Node_Id is Spec : Node_Id; begin Append_To (Stats, Make_Simple_Return_Statement (Loc, Expression => New_Occurrence_Of (Res, Loc))); Spec := Make_Function_Specification (Loc, Defining_Unit_Name => Make_Temporary (Loc, 'F'), Result_Definition => New_Occurrence_Of (Standard_String, Loc)); -- Calls to 'Image use the secondary stack, which must be cleaned up -- after the task name is built. return Make_Subprogram_Body (Loc, Specification => Spec, Declarations => Decls, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats)); end Build_Task_Image_Function; ----------------------------- -- Build_Task_Image_Prefix -- ----------------------------- procedure Build_Task_Image_Prefix (Loc : Source_Ptr; Len : out Entity_Id; Res : out Entity_Id; Pos : out Entity_Id; Prefix : Entity_Id; Sum : Node_Id; Decls : List_Id; Stats : List_Id) is begin Len := Make_Temporary (Loc, 'L', Sum); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Len, Object_Definition => New_Occurrence_Of (Standard_Integer, Loc), Expression => Sum)); Res := Make_Temporary (Loc, 'R'); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Res, Object_Definition => Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List ( Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => New_Occurrence_Of (Len, Loc))))))); Pos := Make_Temporary (Loc, 'P'); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Pos, Object_Definition => New_Occurrence_Of (Standard_Integer, Loc))); -- Pos := Prefix'Length; Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Prefix, Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1))))); -- Res (1 .. Pos) := Prefix; Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Res, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => New_Occurrence_Of (Pos, Loc))), Expression => New_Occurrence_Of (Prefix, Loc))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); end Build_Task_Image_Prefix; ----------------------------- -- Build_Task_Record_Image -- ----------------------------- function Build_Task_Record_Image (Loc : Source_Ptr; Id_Ref : Node_Id; Dyn : Boolean := False) return Node_Id is Len : Entity_Id; -- Total length of generated name Pos : Entity_Id; -- Index into result Res : Entity_Id; -- String to hold result Pref : constant Entity_Id := Make_Temporary (Loc, 'P'); -- Name of enclosing variable, prefix of resulting name Sum : Node_Id; -- Expression to compute total size of string Sel : Entity_Id; -- Entity for selector name Decls : constant List_Id := New_List; Stats : constant List_Id := New_List; begin -- For a dynamic task, the name comes from the target variable. For a -- static one it is a formal of the enclosing init proc. if Dyn then Get_Name_String (Chars (Entity (Prefix (Id_Ref)))); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Pref, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); else Append_To (Decls, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Pref, Subtype_Mark => New_Occurrence_Of (Standard_String, Loc), Name => Make_Identifier (Loc, Name_uTask_Name))); end if; Sel := Make_Temporary (Loc, 'S'); Get_Name_String (Chars (Selector_Name (Id_Ref))); Append_To (Decls, Make_Object_Declaration (Loc, Defining_Identifier => Sel, Object_Definition => New_Occurrence_Of (Standard_String, Loc), Expression => Make_String_Literal (Loc, Strval => String_From_Name_Buffer))); Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1)); Sum := Make_Op_Add (Loc, Left_Opnd => Sum, Right_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => New_Occurrence_Of (Pref, Loc), Expressions => New_List (Make_Integer_Literal (Loc, 1)))); Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats); Set_Character_Literal_Name (Char_Code (Character'Pos ('.'))); -- Res (Pos) := '.'; Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => New_Occurrence_Of (Res, Loc), Expressions => New_List (New_Occurrence_Of (Pos, Loc))), Expression => Make_Character_Literal (Loc, Chars => Name_Find, Char_Literal_Value => UI_From_Int (Character'Pos ('.'))))); Append_To (Stats, Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Pos, Loc), Expression => Make_Op_Add (Loc, Left_Opnd => New_Occurrence_Of (Pos, Loc), Right_Opnd => Make_Integer_Literal (Loc, 1)))); -- Res (Pos .. Len) := Selector; Append_To (Stats, Make_Assignment_Statement (Loc, Name => Make_Slice (Loc, Prefix => New_Occurrence_Of (Res, Loc), Discrete_Range => Make_Range (Loc, Low_Bound => New_Occurrence_Of (Pos, Loc), High_Bound => New_Occurrence_Of (Len, Loc))), Expression => New_Occurrence_Of (Sel, Loc))); return Build_Task_Image_Function (Loc, Decls, Stats, Res); end Build_Task_Record_Image; ---------------------------------- -- Component_May_Be_Bit_Aligned -- ---------------------------------- function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is UT : Entity_Id; begin -- If no component clause, then everything is fine, since the back end -- never bit-misaligns by default, even if there is a pragma Packed for -- the record. if No (Comp) or else No (Component_Clause (Comp)) then return False; end if; UT := Underlying_Type (Etype (Comp)); -- It is only array and record types that cause trouble if not Is_Record_Type (UT) and then not Is_Array_Type (UT) then return False; -- If we know that we have a small (64 bits or less) record or small -- bit-packed array, then everything is fine, since the back end can -- handle these cases correctly. elsif Esize (Comp) <= 64 and then (Is_Record_Type (UT) or else Is_Bit_Packed_Array (UT)) then return False; -- Otherwise if the component is not byte aligned, we know we have the -- nasty unaligned case. elsif Normalized_First_Bit (Comp) /= Uint_0 or else Esize (Comp) mod System_Storage_Unit /= Uint_0 then return True; -- If we are large and byte aligned, then OK at this level else return False; end if; end Component_May_Be_Bit_Aligned; ----------------------------------- -- Corresponding_Runtime_Package -- ----------------------------------- function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is Pkg_Id : RTU_Id := RTU_Null; begin pragma Assert (Is_Concurrent_Type (Typ)); if Ekind (Typ) in Protected_Kind then if Has_Entries (Typ) -- A protected type without entries that covers an interface and -- overrides the abstract routines with protected procedures is -- considered equivalent to a protected type with entries in the -- context of dispatching select statements. It is sufficient to -- check for the presence of an interface list in the declaration -- node to recognize this case. or else Present (Interface_List (Parent (Typ))) or else (((Has_Attach_Handler (Typ) and then not Restricted_Profile) or else Has_Interrupt_Handler (Typ)) and then not Restriction_Active (No_Dynamic_Attachment)) then if Abort_Allowed or else Restriction_Active (No_Entry_Queue) = False or else Number_Entries (Typ) > 1 or else (Has_Attach_Handler (Typ) and then not Restricted_Profile) then Pkg_Id := System_Tasking_Protected_Objects_Entries; else Pkg_Id := System_Tasking_Protected_Objects_Single_Entry; end if; else Pkg_Id := System_Tasking_Protected_Objects; end if; end if; return Pkg_Id; end Corresponding_Runtime_Package; ------------------------------- -- Convert_To_Actual_Subtype -- ------------------------------- procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is Act_ST : Entity_Id; begin Act_ST := Get_Actual_Subtype (Exp); if Act_ST = Etype (Exp) then return; else Rewrite (Exp, Convert_To (Act_ST, Relocate_Node (Exp))); Analyze_And_Resolve (Exp, Act_ST); end if; end Convert_To_Actual_Subtype; ----------------------------------- -- Current_Sem_Unit_Declarations -- ----------------------------------- function Current_Sem_Unit_Declarations return List_Id is U : Node_Id := Unit (Cunit (Current_Sem_Unit)); Decls : List_Id; begin -- If the current unit is a package body, locate the visible -- declarations of the package spec. if Nkind (U) = N_Package_Body then U := Unit (Library_Unit (Cunit (Current_Sem_Unit))); end if; if Nkind (U) = N_Package_Declaration then U := Specification (U); Decls := Visible_Declarations (U); if No (Decls) then Decls := New_List; Set_Visible_Declarations (U, Decls); end if; else Decls := Declarations (U); if No (Decls) then Decls := New_List; Set_Declarations (U, Decls); end if; end if; return Decls; end Current_Sem_Unit_Declarations; ----------------------- -- Duplicate_Subexpr -- ----------------------- function Duplicate_Subexpr (Exp : Node_Id; Name_Req : Boolean := False) return Node_Id is begin Remove_Side_Effects (Exp, Name_Req); return New_Copy_Tree (Exp); end Duplicate_Subexpr; --------------------------------- -- Duplicate_Subexpr_No_Checks -- --------------------------------- function Duplicate_Subexpr_No_Checks (Exp : Node_Id; Name_Req : Boolean := False) return Node_Id is New_Exp : Node_Id; begin Remove_Side_Effects (Exp, Name_Req); New_Exp := New_Copy_Tree (Exp); Remove_Checks (New_Exp); return New_Exp; end Duplicate_Subexpr_No_Checks; ----------------------------------- -- Duplicate_Subexpr_Move_Checks -- ----------------------------------- function Duplicate_Subexpr_Move_Checks (Exp : Node_Id; Name_Req : Boolean := False) return Node_Id is New_Exp : Node_Id; begin Remove_Side_Effects (Exp, Name_Req); New_Exp := New_Copy_Tree (Exp); Remove_Checks (Exp); return New_Exp; end Duplicate_Subexpr_Move_Checks; -------------------- -- Ensure_Defined -- -------------------- procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is IR : Node_Id; begin -- An itype reference must only be created if this is a local itype, so -- that gigi can elaborate it on the proper objstack. if Is_Itype (Typ) and then Scope (Typ) = Current_Scope then IR := Make_Itype_Reference (Sloc (N)); Set_Itype (IR, Typ); Insert_Action (N, IR); end if; end Ensure_Defined; -------------------- -- Entry_Names_OK -- -------------------- function Entry_Names_OK return Boolean is begin return not Restricted_Profile and then not Global_Discard_Names and then not Restriction_Active (No_Implicit_Heap_Allocations) and then not Restriction_Active (No_Local_Allocators); end Entry_Names_OK; ------------------- -- Evaluate_Name -- ------------------- procedure Evaluate_Name (Nam : Node_Id) is K : constant Node_Kind := Nkind (Nam); begin -- For an explicit dereference, we simply force the evaluation of the -- name expression. The dereference provides a value that is the address -- for the renamed object, and it is precisely this value that we want -- to preserve. if K = N_Explicit_Dereference then Force_Evaluation (Prefix (Nam)); -- For a selected component, we simply evaluate the prefix elsif K = N_Selected_Component then Evaluate_Name (Prefix (Nam)); -- For an indexed component, or an attribute reference, we evaluate the -- prefix, which is itself a name, recursively, and then force the -- evaluation of all the subscripts (or attribute expressions). elsif Nkind_In (K, N_Indexed_Component, N_Attribute_Reference) then Evaluate_Name (Prefix (Nam)); declare E : Node_Id; begin E := First (Expressions (Nam)); while Present (E) loop Force_Evaluation (E); if Original_Node (E) /= E then Set_Do_Range_Check (E, Do_Range_Check (Original_Node (E))); end if; Next (E); end loop; end; -- For a slice, we evaluate the prefix, as for the indexed component -- case and then, if there is a range present, either directly or as the -- constraint of a discrete subtype indication, we evaluate the two -- bounds of this range. elsif K = N_Slice then Evaluate_Name (Prefix (Nam)); declare DR : constant Node_Id := Discrete_Range (Nam); Constr : Node_Id; Rexpr : Node_Id; begin if Nkind (DR) = N_Range then Force_Evaluation (Low_Bound (DR)); Force_Evaluation (High_Bound (DR)); elsif Nkind (DR) = N_Subtype_Indication then Constr := Constraint (DR); if Nkind (Constr) = N_Range_Constraint then Rexpr := Range_Expression (Constr); Force_Evaluation (Low_Bound (Rexpr)); Force_Evaluation (High_Bound (Rexpr)); end if; end if; end; -- For a type conversion, the expression of the conversion must be the -- name of an object, and we simply need to evaluate this name. elsif K = N_Type_Conversion then Evaluate_Name (Expression (Nam)); -- For a function call, we evaluate the call elsif K = N_Function_Call then Force_Evaluation (Nam); -- The remaining cases are direct name, operator symbol and character -- literal. In all these cases, we do nothing, since we want to -- reevaluate each time the renamed object is used. else return; end if; end Evaluate_Name; --------------------- -- Evolve_And_Then -- --------------------- procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is begin if No (Cond) then Cond := Cond1; else Cond := Make_And_Then (Sloc (Cond1), Left_Opnd => Cond, Right_Opnd => Cond1); end if; end Evolve_And_Then; -------------------- -- Evolve_Or_Else -- -------------------- procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is begin if No (Cond) then Cond := Cond1; else Cond := Make_Or_Else (Sloc (Cond1), Left_Opnd => Cond, Right_Opnd => Cond1); end if; end Evolve_Or_Else; ------------------------------ -- Expand_Subtype_From_Expr -- ------------------------------ -- This function is applicable for both static and dynamic allocation of -- objects which are constrained by an initial expression. Basically it -- transforms an unconstrained subtype indication into a constrained one. -- The expression may also be transformed in certain cases in order to -- avoid multiple evaluation. In the static allocation case, the general -- scheme is: -- Val : T := Expr; -- is transformed into -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr; -- -- Here are the main cases : -- -- <if Expr is a Slice> -- Val : T ([Index_Subtype (Expr)]) := Expr; -- -- <elsif Expr is a String Literal> -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr; -- -- <elsif Expr is Constrained> -- subtype T is Type_Of_Expr -- Val : T := Expr; -- -- <elsif Expr is an entity_name> -- Val : T (constraints taken from Expr) := Expr; -- -- <else> -- type Axxx is access all T; -- Rval : Axxx := Expr'ref; -- Val : T (constraints taken from Rval) := Rval.all; -- ??? note: when the Expression is allocated in the secondary stack -- we could use it directly instead of copying it by declaring -- Val : T (...) renames Rval.all procedure Expand_Subtype_From_Expr (N : Node_Id; Unc_Type : Entity_Id; Subtype_Indic : Node_Id; Exp : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Exp_Typ : constant Entity_Id := Etype (Exp); T : Entity_Id; begin -- In general we cannot build the subtype if expansion is disabled, -- because internal entities may not have been defined. However, to -- avoid some cascaded errors, we try to continue when the expression is -- an array (or string), because it is safe to compute the bounds. It is -- in fact required to do so even in a generic context, because there -- may be constants that depend on the bounds of a string literal, both -- standard string types and more generally arrays of characters. if not Expander_Active and then (No (Etype (Exp)) or else not Is_String_Type (Etype (Exp))) then return; end if; if Nkind (Exp) = N_Slice then declare Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ)); begin Rewrite (Subtype_Indic, Make_Subtype_Indication (Loc, Subtype_Mark => New_Reference_To (Unc_Type, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List (New_Reference_To (Slice_Type, Loc))))); -- This subtype indication may be used later for constraint checks -- we better make sure that if a variable was used as a bound of -- of the original slice, its value is frozen. Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type))); Force_Evaluation (High_Bound (Scalar_Range (Slice_Type))); end; elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then Rewrite (Subtype_Indic, Make_Subtype_Indication (Loc, Subtype_Mark => New_Reference_To (Unc_Type, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List ( Make_Literal_Range (Loc, Literal_Typ => Exp_Typ))))); elsif Is_Constrained (Exp_Typ) and then not Is_Class_Wide_Type (Unc_Type) then if Is_Itype (Exp_Typ) then -- Within an initialization procedure, a selected component -- denotes a component of the enclosing record, and it appears as -- an actual in a call to its own initialization procedure. If -- this component depends on the outer discriminant, we must -- generate the proper actual subtype for it. if Nkind (Exp) = N_Selected_Component and then Within_Init_Proc then declare Decl : constant Node_Id := Build_Actual_Subtype_Of_Component (Exp_Typ, Exp); begin if Present (Decl) then Insert_Action (N, Decl); T := Defining_Identifier (Decl); else T := Exp_Typ; end if; end; -- No need to generate a new one (new what???) else T := Exp_Typ; end if; else T := Make_Temporary (Loc, 'T'); Insert_Action (N, Make_Subtype_Declaration (Loc, Defining_Identifier => T, Subtype_Indication => New_Reference_To (Exp_Typ, Loc))); -- This type is marked as an itype even though it has an explicit -- declaration since otherwise Is_Generic_Actual_Type can get -- set, resulting in the generation of spurious errors. (See -- sem_ch8.Analyze_Package_Renaming and sem_type.covers) Set_Is_Itype (T); Set_Associated_Node_For_Itype (T, Exp); end if; Rewrite (Subtype_Indic, New_Reference_To (T, Loc)); -- Nothing needs to be done for private types with unknown discriminants -- if the underlying type is not an unconstrained composite type or it -- is an unchecked union. elsif Is_Private_Type (Unc_Type) and then Has_Unknown_Discriminants (Unc_Type) and then (not Is_Composite_Type (Underlying_Type (Unc_Type)) or else Is_Constrained (Underlying_Type (Unc_Type)) or else Is_Unchecked_Union (Underlying_Type (Unc_Type))) then null; -- Case of derived type with unknown discriminants where the parent type -- also has unknown discriminants. elsif Is_Record_Type (Unc_Type) and then not Is_Class_Wide_Type (Unc_Type) and then Has_Unknown_Discriminants (Unc_Type) and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type)) then -- Nothing to be done if no underlying record view available if No (Underlying_Record_View (Unc_Type)) then null; -- Otherwise use the Underlying_Record_View to create the proper -- constrained subtype for an object of a derived type with unknown -- discriminants. else Remove_Side_Effects (Exp); Rewrite (Subtype_Indic, Make_Subtype_From_Expr (Exp, Underlying_Record_View (Unc_Type))); end if; -- Renamings of class-wide interface types require no equivalent -- constrained type declarations because we only need to reference -- the tag component associated with the interface. The same is -- presumably true for class-wide types in general, so this test -- is broadened to include all class-wide renamings, which also -- avoids cases of unbounded recursion in Remove_Side_Effects. -- (Is this really correct, or are there some cases of class-wide -- renamings that require action in this procedure???) elsif Present (N) and then Nkind (N) = N_Object_Renaming_Declaration and then Is_Class_Wide_Type (Unc_Type) then null; -- In Ada 95 nothing to be done if the type of the expression is limited -- because in this case the expression cannot be copied, and its use can -- only be by reference. -- In Ada 2005 the context can be an object declaration whose expression -- is a function that returns in place. If the nominal subtype has -- unknown discriminants, the call still provides constraints on the -- object, and we have to create an actual subtype from it. -- If the type is class-wide, the expression is dynamically tagged and -- we do not create an actual subtype either. Ditto for an interface. -- For now this applies only if the type is immutably limited, and the -- function being called is build-in-place. This will have to be revised -- when build-in-place functions are generalized to other types. elsif Is_Immutably_Limited_Type (Exp_Typ) and then (Is_Class_Wide_Type (Exp_Typ) or else Is_Interface (Exp_Typ) or else not Has_Unknown_Discriminants (Exp_Typ) or else not Is_Composite_Type (Unc_Type)) then null; -- For limited objects initialized with build in place function calls, -- nothing to be done; otherwise we prematurely introduce an N_Reference -- node in the expression initializing the object, which breaks the -- circuitry that detects and adds the additional arguments to the -- called function. elsif Is_Build_In_Place_Function_Call (Exp) then null; else Remove_Side_Effects (Exp); Rewrite (Subtype_Indic, Make_Subtype_From_Expr (Exp, Unc_Type)); end if; end Expand_Subtype_From_Expr; -------------------- -- Find_Init_Call -- -------------------- function Find_Init_Call (Var : Entity_Id; Rep_Clause : Node_Id) return Node_Id is Typ : constant Entity_Id := Etype (Var); Init_Proc : Entity_Id; -- Initialization procedure for Typ function Find_Init_Call_In_List (From : Node_Id) return Node_Id; -- Look for init call for Var starting at From and scanning the -- enclosing list until Rep_Clause or the end of the list is reached. ---------------------------- -- Find_Init_Call_In_List -- ---------------------------- function Find_Init_Call_In_List (From : Node_Id) return Node_Id is Init_Call : Node_Id; begin Init_Call := From; while Present (Init_Call) and then Init_Call /= Rep_Clause loop if Nkind (Init_Call) = N_Procedure_Call_Statement and then Is_Entity_Name (Name (Init_Call)) and then Entity (Name (Init_Call)) = Init_Proc then return Init_Call; end if; Next (Init_Call); end loop; return Empty; end Find_Init_Call_In_List; Init_Call : Node_Id; -- Start of processing for Find_Init_Call begin if not Has_Non_Null_Base_Init_Proc (Typ) then -- No init proc for the type, so obviously no call to be found return Empty; end if; Init_Proc := Base_Init_Proc (Typ); -- First scan the list containing the declaration of Var Init_Call := Find_Init_Call_In_List (From => Next (Parent (Var))); -- If not found, also look on Var's freeze actions list, if any, since -- the init call may have been moved there (case of an address clause -- applying to Var). if No (Init_Call) and then Present (Freeze_Node (Var)) then Init_Call := Find_Init_Call_In_List (First (Actions (Freeze_Node (Var)))); end if; return Init_Call; end Find_Init_Call; ------------------------ -- Find_Interface_ADT -- ------------------------ function Find_Interface_ADT (T : Entity_Id; Iface : Entity_Id) return Elmt_Id is ADT : Elmt_Id; Typ : Entity_Id := T; begin pragma Assert (Is_Interface (Iface)); -- Handle private types if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then Typ := Full_View (Typ); end if; -- Handle access types if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); end if; -- Handle task and protected types implementing interfaces if Is_Concurrent_Type (Typ) then Typ := Corresponding_Record_Type (Typ); end if; pragma Assert (not Is_Class_Wide_Type (Typ) and then Ekind (Typ) /= E_Incomplete_Type); if Is_Ancestor (Iface, Typ, Use_Full_View => True) then return First_Elmt (Access_Disp_Table (Typ)); else ADT := Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ)))); while Present (ADT) and then Present (Related_Type (Node (ADT))) and then Related_Type (Node (ADT)) /= Iface and then not Is_Ancestor (Iface, Related_Type (Node (ADT)), Use_Full_View => True) loop Next_Elmt (ADT); end loop; pragma Assert (Present (Related_Type (Node (ADT)))); return ADT; end if; end Find_Interface_ADT; ------------------------ -- Find_Interface_Tag -- ------------------------ function Find_Interface_Tag (T : Entity_Id; Iface : Entity_Id) return Entity_Id is AI_Tag : Entity_Id; Found : Boolean := False; Typ : Entity_Id := T; procedure Find_Tag (Typ : Entity_Id); -- Internal subprogram used to recursively climb to the ancestors -------------- -- Find_Tag -- -------------- procedure Find_Tag (Typ : Entity_Id) is AI_Elmt : Elmt_Id; AI : Node_Id; begin -- This routine does not handle the case in which the interface is an -- ancestor of Typ. That case is handled by the enclosing subprogram. pragma Assert (Typ /= Iface); -- Climb to the root type handling private types if Present (Full_View (Etype (Typ))) then if Full_View (Etype (Typ)) /= Typ then Find_Tag (Full_View (Etype (Typ))); end if; elsif Etype (Typ) /= Typ then Find_Tag (Etype (Typ)); end if; -- Traverse the list of interfaces implemented by the type if not Found and then Present (Interfaces (Typ)) and then not (Is_Empty_Elmt_List (Interfaces (Typ))) then -- Skip the tag associated with the primary table pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag)); AI_Tag := Next_Tag_Component (First_Tag_Component (Typ)); pragma Assert (Present (AI_Tag)); AI_Elmt := First_Elmt (Interfaces (Typ)); while Present (AI_Elmt) loop AI := Node (AI_Elmt); if AI = Iface or else Is_Ancestor (Iface, AI, Use_Full_View => True) then Found := True; return; end if; AI_Tag := Next_Tag_Component (AI_Tag); Next_Elmt (AI_Elmt); end loop; end if; end Find_Tag; -- Start of processing for Find_Interface_Tag begin pragma Assert (Is_Interface (Iface)); -- Handle access types if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); end if; -- Handle class-wide types if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; -- Handle private types if Has_Private_Declaration (Typ) and then Present (Full_View (Typ)) then Typ := Full_View (Typ); end if; -- Handle entities from the limited view if Ekind (Typ) = E_Incomplete_Type then pragma Assert (Present (Non_Limited_View (Typ))); Typ := Non_Limited_View (Typ); end if; -- Handle task and protected types implementing interfaces if Is_Concurrent_Type (Typ) then Typ := Corresponding_Record_Type (Typ); end if; -- If the interface is an ancestor of the type, then it shared the -- primary dispatch table. if Is_Ancestor (Iface, Typ, Use_Full_View => True) then pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag)); return First_Tag_Component (Typ); -- Otherwise we need to search for its associated tag component else Find_Tag (Typ); pragma Assert (Found); return AI_Tag; end if; end Find_Interface_Tag; ------------------ -- Find_Prim_Op -- ------------------ function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is Prim : Elmt_Id; Typ : Entity_Id := T; Op : Entity_Id; begin if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; Typ := Underlying_Type (Typ); -- Loop through primitive operations Prim := First_Elmt (Primitive_Operations (Typ)); while Present (Prim) loop Op := Node (Prim); -- We can retrieve primitive operations by name if it is an internal -- name. For equality we must check that both of its operands have -- the same type, to avoid confusion with user-defined equalities -- than may have a non-symmetric signature. exit when Chars (Op) = Name and then (Name /= Name_Op_Eq or else Etype (First_Formal (Op)) = Etype (Last_Formal (Op))); Next_Elmt (Prim); -- Raise Program_Error if no primitive found if No (Prim) then raise Program_Error; end if; end loop; return Node (Prim); end Find_Prim_Op; ------------------ -- Find_Prim_Op -- ------------------ function Find_Prim_Op (T : Entity_Id; Name : TSS_Name_Type) return Entity_Id is Inher_Op : Entity_Id := Empty; Own_Op : Entity_Id := Empty; Prim_Elmt : Elmt_Id; Prim_Id : Entity_Id; Typ : Entity_Id := T; begin if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; Typ := Underlying_Type (Typ); -- This search is based on the assertion that the dispatching version -- of the TSS routine always precedes the real primitive. Prim_Elmt := First_Elmt (Primitive_Operations (Typ)); while Present (Prim_Elmt) loop Prim_Id := Node (Prim_Elmt); if Is_TSS (Prim_Id, Name) then if Present (Alias (Prim_Id)) then Inher_Op := Prim_Id; else Own_Op := Prim_Id; end if; end if; Next_Elmt (Prim_Elmt); end loop; if Present (Own_Op) then return Own_Op; elsif Present (Inher_Op) then return Inher_Op; else raise Program_Error; end if; end Find_Prim_Op; ---------------------------- -- Find_Protection_Object -- ---------------------------- function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is S : Entity_Id; begin S := Scop; while Present (S) loop if (Ekind (S) = E_Entry or else Ekind (S) = E_Entry_Family or else Ekind (S) = E_Function or else Ekind (S) = E_Procedure) and then Present (Protection_Object (S)) then return Protection_Object (S); end if; S := Scope (S); end loop; -- If we do not find a Protection object in the scope chain, then -- something has gone wrong, most likely the object was never created. raise Program_Error; end Find_Protection_Object; -------------------------- -- Find_Protection_Type -- -------------------------- function Find_Protection_Type (Conc_Typ : Entity_Id) return Entity_Id is Comp : Entity_Id; Typ : Entity_Id := Conc_Typ; begin if Is_Concurrent_Type (Typ) then Typ := Corresponding_Record_Type (Typ); end if; -- Since restriction violations are not considered serious errors, the -- expander remains active, but may leave the corresponding record type -- malformed. In such cases, component _object is not available so do -- not look for it. if not Analyzed (Typ) then return Empty; end if; Comp := First_Component (Typ); while Present (Comp) loop if Chars (Comp) = Name_uObject then return Base_Type (Etype (Comp)); end if; Next_Component (Comp); end loop; -- The corresponding record of a protected type should always have an -- _object field. raise Program_Error; end Find_Protection_Type; ---------------------- -- Force_Evaluation -- ---------------------- procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is begin Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True); end Force_Evaluation; --------------------------------- -- Fully_Qualified_Name_String -- --------------------------------- function Fully_Qualified_Name_String (E : Entity_Id) return String_Id is procedure Internal_Full_Qualified_Name (E : Entity_Id); -- Compute recursively the qualified name without NUL at the end, adding -- it to the currently started string being generated ---------------------------------- -- Internal_Full_Qualified_Name -- ---------------------------------- procedure Internal_Full_Qualified_Name (E : Entity_Id) is Ent : Entity_Id; begin -- Deal properly with child units if Nkind (E) = N_Defining_Program_Unit_Name then Ent := Defining_Identifier (E); else Ent := E; end if; -- Compute qualification recursively (only "Standard" has no scope) if Present (Scope (Scope (Ent))) then Internal_Full_Qualified_Name (Scope (Ent)); Store_String_Char (Get_Char_Code ('.')); end if; -- Every entity should have a name except some expanded blocks -- don't bother about those. if Chars (Ent) = No_Name then return; end if; -- Generates the entity name in upper case Get_Decoded_Name_String (Chars (Ent)); Set_All_Upper_Case; Store_String_Chars (Name_Buffer (1 .. Name_Len)); return; end Internal_Full_Qualified_Name; -- Start of processing for Full_Qualified_Name begin Start_String; Internal_Full_Qualified_Name (E); Store_String_Char (Get_Char_Code (ASCII.NUL)); return End_String; end Fully_Qualified_Name_String; ------------------------ -- Generate_Poll_Call -- ------------------------ procedure Generate_Poll_Call (N : Node_Id) is begin -- No poll call if polling not active if not Polling_Required then return; -- Otherwise generate require poll call else Insert_Before_And_Analyze (N, Make_Procedure_Call_Statement (Sloc (N), Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N)))); end if; end Generate_Poll_Call; --------------------------------- -- Get_Current_Value_Condition -- --------------------------------- -- Note: the implementation of this procedure is very closely tied to the -- implementation of Set_Current_Value_Condition. In the Get procedure, we -- interpret Current_Value fields set by the Set procedure, so the two -- procedures need to be closely coordinated. procedure Get_Current_Value_Condition (Var : Node_Id; Op : out Node_Kind; Val : out Node_Id) is Loc : constant Source_Ptr := Sloc (Var); Ent : constant Entity_Id := Entity (Var); procedure Process_Current_Value_Condition (N : Node_Id; S : Boolean); -- N is an expression which holds either True (S = True) or False (S = -- False) in the condition. This procedure digs out the expression and -- if it refers to Ent, sets Op and Val appropriately. ------------------------------------- -- Process_Current_Value_Condition -- ------------------------------------- procedure Process_Current_Value_Condition (N : Node_Id; S : Boolean) is Cond : Node_Id; Sens : Boolean; begin Cond := N; Sens := S; -- Deal with NOT operators, inverting sense while Nkind (Cond) = N_Op_Not loop Cond := Right_Opnd (Cond); Sens := not Sens; end loop; -- Deal with AND THEN and AND cases if Nkind (Cond) = N_And_Then or else Nkind (Cond) = N_Op_And then -- Don't ever try to invert a condition that is of the form of an -- AND or AND THEN (since we are not doing sufficiently general -- processing to allow this). if Sens = False then Op := N_Empty; Val := Empty; return; end if; -- Recursively process AND and AND THEN branches Process_Current_Value_Condition (Left_Opnd (Cond), True); if Op /= N_Empty then return; end if; Process_Current_Value_Condition (Right_Opnd (Cond), True); return; -- Case of relational operator elsif Nkind (Cond) in N_Op_Compare then Op := Nkind (Cond); -- Invert sense of test if inverted test if Sens = False then case Op is when N_Op_Eq => Op := N_Op_Ne; when N_Op_Ne => Op := N_Op_Eq; when N_Op_Lt => Op := N_Op_Ge; when N_Op_Gt => Op := N_Op_Le; when N_Op_Le => Op := N_Op_Gt; when N_Op_Ge => Op := N_Op_Lt; when others => raise Program_Error; end case; end if; -- Case of entity op value if Is_Entity_Name (Left_Opnd (Cond)) and then Ent = Entity (Left_Opnd (Cond)) and then Compile_Time_Known_Value (Right_Opnd (Cond)) then Val := Right_Opnd (Cond); -- Case of value op entity elsif Is_Entity_Name (Right_Opnd (Cond)) and then Ent = Entity (Right_Opnd (Cond)) and then Compile_Time_Known_Value (Left_Opnd (Cond)) then Val := Left_Opnd (Cond); -- We are effectively swapping operands case Op is when N_Op_Eq => null; when N_Op_Ne => null; when N_Op_Lt => Op := N_Op_Gt; when N_Op_Gt => Op := N_Op_Lt; when N_Op_Le => Op := N_Op_Ge; when N_Op_Ge => Op := N_Op_Le; when others => raise Program_Error; end case; else Op := N_Empty; end if; return; -- Case of Boolean variable reference, return as though the -- reference had said var = True. else if Is_Entity_Name (Cond) and then Ent = Entity (Cond) then Val := New_Occurrence_Of (Standard_True, Sloc (Cond)); if Sens = False then Op := N_Op_Ne; else Op := N_Op_Eq; end if; end if; end if; end Process_Current_Value_Condition; -- Start of processing for Get_Current_Value_Condition begin Op := N_Empty; Val := Empty; -- Immediate return, nothing doing, if this is not an object if Ekind (Ent) not in Object_Kind then return; end if; -- Otherwise examine current value declare CV : constant Node_Id := Current_Value (Ent); Sens : Boolean; Stm : Node_Id; begin -- If statement. Condition is known true in THEN section, known False -- in any ELSIF or ELSE part, and unknown outside the IF statement. if Nkind (CV) = N_If_Statement then -- Before start of IF statement if Loc < Sloc (CV) then return; -- After end of IF statement elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then return; end if; -- At this stage we know that we are within the IF statement, but -- unfortunately, the tree does not record the SLOC of the ELSE so -- we cannot use a simple SLOC comparison to distinguish between -- the then/else statements, so we have to climb the tree. declare N : Node_Id; begin N := Parent (Var); while Parent (N) /= CV loop N := Parent (N); -- If we fall off the top of the tree, then that's odd, but -- perhaps it could occur in some error situation, and the -- safest response is simply to assume that the outcome of -- the condition is unknown. No point in bombing during an -- attempt to optimize things. if No (N) then return; end if; end loop; -- Now we have N pointing to a node whose parent is the IF -- statement in question, so now we can tell if we are within -- the THEN statements. if Is_List_Member (N) and then List_Containing (N) = Then_Statements (CV) then Sens := True; -- If the variable reference does not come from source, we -- cannot reliably tell whether it appears in the else part. -- In particular, if it appears in generated code for a node -- that requires finalization, it may be attached to a list -- that has not been yet inserted into the code. For now, -- treat it as unknown. elsif not Comes_From_Source (N) then return; -- Otherwise we must be in ELSIF or ELSE part else Sens := False; end if; end; -- ELSIF part. Condition is known true within the referenced -- ELSIF, known False in any subsequent ELSIF or ELSE part, -- and unknown before the ELSE part or after the IF statement. elsif Nkind (CV) = N_Elsif_Part then -- if the Elsif_Part had condition_actions, the elsif has been -- rewritten as a nested if, and the original elsif_part is -- detached from the tree, so there is no way to obtain useful -- information on the current value of the variable. -- Can this be improved ??? if No (Parent (CV)) then return; end if; Stm := Parent (CV); -- Before start of ELSIF part if Loc < Sloc (CV) then return; -- After end of IF statement elsif Loc >= Sloc (Stm) + Text_Ptr (UI_To_Int (End_Span (Stm))) then return; end if; -- Again we lack the SLOC of the ELSE, so we need to climb the -- tree to see if we are within the ELSIF part in question. declare N : Node_Id; begin N := Parent (Var); while Parent (N) /= Stm loop N := Parent (N); -- If we fall off the top of the tree, then that's odd, but -- perhaps it could occur in some error situation, and the -- safest response is simply to assume that the outcome of -- the condition is unknown. No point in bombing during an -- attempt to optimize things. if No (N) then return; end if; end loop; -- Now we have N pointing to a node whose parent is the IF -- statement in question, so see if is the ELSIF part we want. -- the THEN statements. if N = CV then Sens := True; -- Otherwise we must be in subsequent ELSIF or ELSE part else Sens := False; end if; end; -- Iteration scheme of while loop. The condition is known to be -- true within the body of the loop. elsif Nkind (CV) = N_Iteration_Scheme then declare Loop_Stmt : constant Node_Id := Parent (CV); begin -- Before start of body of loop if Loc < Sloc (Loop_Stmt) then return; -- After end of LOOP statement elsif Loc >= Sloc (End_Label (Loop_Stmt)) then return; -- We are within the body of the loop else Sens := True; end if; end; -- All other cases of Current_Value settings else return; end if; -- If we fall through here, then we have a reportable condition, Sens -- is True if the condition is true and False if it needs inverting. Process_Current_Value_Condition (Condition (CV), Sens); end; end Get_Current_Value_Condition; --------------------- -- Get_Stream_Size -- --------------------- function Get_Stream_Size (E : Entity_Id) return Uint is begin -- If we have a Stream_Size clause for this type use it if Has_Stream_Size_Clause (E) then return Static_Integer (Expression (Stream_Size_Clause (E))); -- Otherwise the Stream_Size if the size of the type else return Esize (E); end if; end Get_Stream_Size; --------------------------- -- Has_Access_Constraint -- --------------------------- function Has_Access_Constraint (E : Entity_Id) return Boolean is Disc : Entity_Id; T : constant Entity_Id := Etype (E); begin if Has_Per_Object_Constraint (E) and then Has_Discriminants (T) then Disc := First_Discriminant (T); while Present (Disc) loop if Is_Access_Type (Etype (Disc)) then return True; end if; Next_Discriminant (Disc); end loop; return False; else return False; end if; end Has_Access_Constraint; ---------------------------------- -- Has_Following_Address_Clause -- ---------------------------------- -- Should this function check the private part in a package ??? function Has_Following_Address_Clause (D : Node_Id) return Boolean is Id : constant Entity_Id := Defining_Identifier (D); Decl : Node_Id; begin Decl := Next (D); while Present (Decl) loop if Nkind (Decl) = N_At_Clause and then Chars (Identifier (Decl)) = Chars (Id) then return True; elsif Nkind (Decl) = N_Attribute_Definition_Clause and then Chars (Decl) = Name_Address and then Chars (Name (Decl)) = Chars (Id) then return True; end if; Next (Decl); end loop; return False; end Has_Following_Address_Clause; -------------------- -- Homonym_Number -- -------------------- function Homonym_Number (Subp : Entity_Id) return Nat is Count : Nat; Hom : Entity_Id; begin Count := 1; Hom := Homonym (Subp); while Present (Hom) loop if Scope (Hom) = Scope (Subp) then Count := Count + 1; end if; Hom := Homonym (Hom); end loop; return Count; end Homonym_Number; ----------------------------------- -- In_Library_Level_Package_Body -- ----------------------------------- function In_Library_Level_Package_Body (Id : Entity_Id) return Boolean is begin -- First determine whether the entity appears at the library level, then -- look at the containing unit. if Is_Library_Level_Entity (Id) then declare Container : constant Node_Id := Cunit (Get_Source_Unit (Id)); begin return Nkind (Unit (Container)) = N_Package_Body; end; end if; return False; end In_Library_Level_Package_Body; ------------------------------ -- In_Unconditional_Context -- ------------------------------ function In_Unconditional_Context (Node : Node_Id) return Boolean is P : Node_Id; begin P := Node; while Present (P) loop case Nkind (P) is when N_Subprogram_Body => return True; when N_If_Statement => return False; when N_Loop_Statement => return False; when N_Case_Statement => return False; when others => P := Parent (P); end case; end loop; return False; end In_Unconditional_Context; ------------------- -- Insert_Action -- ------------------- procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is begin if Present (Ins_Action) then Insert_Actions (Assoc_Node, New_List (Ins_Action)); end if; end Insert_Action; -- Version with check(s) suppressed procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id) is begin Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress); end Insert_Action; ------------------------- -- Insert_Action_After -- ------------------------- procedure Insert_Action_After (Assoc_Node : Node_Id; Ins_Action : Node_Id) is begin Insert_Actions_After (Assoc_Node, New_List (Ins_Action)); end Insert_Action_After; -------------------- -- Insert_Actions -- -------------------- procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is N : Node_Id; P : Node_Id; Wrapped_Node : Node_Id := Empty; begin if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then return; end if; -- Ignore insert of actions from inside default expression (or other -- similar "spec expression") in the special spec-expression analyze -- mode. Any insertions at this point have no relevance, since we are -- only doing the analyze to freeze the types of any static expressions. -- See section "Handling of Default Expressions" in the spec of package -- Sem for further details. if In_Spec_Expression then return; end if; -- If the action derives from stuff inside a record, then the actions -- are attached to the current scope, to be inserted and analyzed on -- exit from the scope. The reason for this is that we may also be -- generating freeze actions at the same time, and they must eventually -- be elaborated in the correct order. if Is_Record_Type (Current_Scope) and then not Is_Frozen (Current_Scope) then if No (Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions) then Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions := Ins_Actions; else Append_List (Ins_Actions, Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions); end if; return; end if; -- We now intend to climb up the tree to find the right point to -- insert the actions. We start at Assoc_Node, unless this node is a -- subexpression in which case we start with its parent. We do this for -- two reasons. First it speeds things up. Second, if Assoc_Node is -- itself one of the special nodes like N_And_Then, then we assume that -- an initial request to insert actions for such a node does not expect -- the actions to get deposited in the node for later handling when the -- node is expanded, since clearly the node is being dealt with by the -- caller. Note that in the subexpression case, N is always the child we -- came from. -- N_Raise_xxx_Error is an annoying special case, it is a statement if -- it has type Standard_Void_Type, and a subexpression otherwise. -- otherwise. Procedure attribute references are also statements. if Nkind (Assoc_Node) in N_Subexpr and then (Nkind (Assoc_Node) in N_Raise_xxx_Error or else Etype (Assoc_Node) /= Standard_Void_Type) and then (Nkind (Assoc_Node) /= N_Attribute_Reference or else not Is_Procedure_Attribute_Name (Attribute_Name (Assoc_Node))) then P := Assoc_Node; -- ??? does not agree with above! N := Parent (Assoc_Node); -- Non-subexpression case. Note that N is initially Empty in this case -- (N is only guaranteed Non-Empty in the subexpr case). else P := Assoc_Node; N := Empty; end if; -- Capture root of the transient scope if Scope_Is_Transient then Wrapped_Node := Node_To_Be_Wrapped; end if; loop pragma Assert (Present (P)); case Nkind (P) is -- Case of right operand of AND THEN or OR ELSE. Put the actions -- in the Actions field of the right operand. They will be moved -- out further when the AND THEN or OR ELSE operator is expanded. -- Nothing special needs to be done for the left operand since -- in that case the actions are executed unconditionally. when N_Short_Circuit => if N = Right_Opnd (P) then -- We are now going to either append the actions to the -- actions field of the short-circuit operation. We will -- also analyze the actions now. -- This analysis is really too early, the proper thing would -- be to just park them there now, and only analyze them if -- we find we really need them, and to it at the proper -- final insertion point. However attempting to this proved -- tricky, so for now we just kill current values before and -- after the analyze call to make sure we avoid peculiar -- optimizations from this out of order insertion. Kill_Current_Values; if Present (Actions (P)) then Insert_List_After_And_Analyze (Last (Actions (P)), Ins_Actions); else Set_Actions (P, Ins_Actions); Analyze_List (Actions (P)); end if; Kill_Current_Values; return; end if; -- Then or Else operand of conditional expression. Add actions to -- Then_Actions or Else_Actions field as appropriate. The actions -- will be moved further out when the conditional is expanded. when N_Conditional_Expression => declare ThenX : constant Node_Id := Next (First (Expressions (P))); ElseX : constant Node_Id := Next (ThenX); begin -- If the enclosing expression is already analyzed, as -- is the case for nested elaboration checks, insert the -- conditional further out. if Analyzed (P) then null; -- Actions belong to the then expression, temporarily place -- them as Then_Actions of the conditional expr. They will -- be moved to the proper place later when the conditional -- expression is expanded. elsif N = ThenX then if Present (Then_Actions (P)) then Insert_List_After_And_Analyze (Last (Then_Actions (P)), Ins_Actions); else Set_Then_Actions (P, Ins_Actions); Analyze_List (Then_Actions (P)); end if; return; -- Actions belong to the else expression, temporarily -- place them as Else_Actions of the conditional expr. -- They will be moved to the proper place later when -- the conditional expression is expanded. elsif N = ElseX then if Present (Else_Actions (P)) then Insert_List_After_And_Analyze (Last (Else_Actions (P)), Ins_Actions); else Set_Else_Actions (P, Ins_Actions); Analyze_List (Else_Actions (P)); end if; return; -- Actions belong to the condition. In this case they are -- unconditionally executed, and so we can continue the -- search for the proper insert point. else null; end if; end; -- Alternative of case expression, we place the action in the -- Actions field of the case expression alternative, this will -- be handled when the case expression is expanded. when N_Case_Expression_Alternative => if Present (Actions (P)) then Insert_List_After_And_Analyze (Last (Actions (P)), Ins_Actions); else Set_Actions (P, Ins_Actions); Analyze_List (Actions (P)); end if; return; -- Case of appearing within an Expressions_With_Actions node. We -- prepend the actions to the list of actions already there, if -- the node has not been analyzed yet. Otherwise find insertion -- location further up the tree. when N_Expression_With_Actions => if not Analyzed (P) then Prepend_List (Ins_Actions, Actions (P)); return; end if; -- Case of appearing in the condition of a while expression or -- elsif. We insert the actions into the Condition_Actions field. -- They will be moved further out when the while loop or elsif -- is analyzed. when N_Iteration_Scheme | N_Elsif_Part => if N = Condition (P) then if Present (Condition_Actions (P)) then Insert_List_After_And_Analyze (Last (Condition_Actions (P)), Ins_Actions); else Set_Condition_Actions (P, Ins_Actions); -- Set the parent of the insert actions explicitly. This -- is not a syntactic field, but we need the parent field -- set, in particular so that freeze can understand that -- it is dealing with condition actions, and properly -- insert the freezing actions. Set_Parent (Ins_Actions, P); Analyze_List (Condition_Actions (P)); end if; return; end if; -- Statements, declarations, pragmas, representation clauses when -- Statements N_Procedure_Call_Statement | N_Statement_Other_Than_Procedure_Call | -- Pragmas N_Pragma | -- Representation_Clause N_At_Clause | N_Attribute_Definition_Clause | N_Enumeration_Representation_Clause | N_Record_Representation_Clause | -- Declarations N_Abstract_Subprogram_Declaration | N_Entry_Body | N_Exception_Declaration | N_Exception_Renaming_Declaration | N_Expression_Function | N_Formal_Abstract_Subprogram_Declaration | N_Formal_Concrete_Subprogram_Declaration | N_Formal_Object_Declaration | N_Formal_Type_Declaration | N_Full_Type_Declaration | N_Function_Instantiation | N_Generic_Function_Renaming_Declaration | N_Generic_Package_Declaration | N_Generic_Package_Renaming_Declaration | N_Generic_Procedure_Renaming_Declaration | N_Generic_Subprogram_Declaration | N_Implicit_Label_Declaration | N_Incomplete_Type_Declaration | N_Number_Declaration | N_Object_Declaration | N_Object_Renaming_Declaration | N_Package_Body | N_Package_Body_Stub | N_Package_Declaration | N_Package_Instantiation | N_Package_Renaming_Declaration | N_Private_Extension_Declaration | N_Private_Type_Declaration | N_Procedure_Instantiation | N_Protected_Body | N_Protected_Body_Stub | N_Protected_Type_Declaration | N_Single_Task_Declaration | N_Subprogram_Body | N_Subprogram_Body_Stub | N_Subprogram_Declaration | N_Subprogram_Renaming_Declaration | N_Subtype_Declaration | N_Task_Body | N_Task_Body_Stub | N_Task_Type_Declaration | -- Use clauses can appear in lists of declarations N_Use_Package_Clause | N_Use_Type_Clause | -- Freeze entity behaves like a declaration or statement N_Freeze_Entity => -- Do not insert here if the item is not a list member (this -- happens for example with a triggering statement, and the -- proper approach is to insert before the entire select). if not Is_List_Member (P) then null; -- Do not insert if parent of P is an N_Component_Association -- node (i.e. we are in the context of an N_Aggregate or -- N_Extension_Aggregate node. In this case we want to insert -- before the entire aggregate. elsif Nkind (Parent (P)) = N_Component_Association then null; -- Do not insert if the parent of P is either an N_Variant node -- or an N_Record_Definition node, meaning in either case that -- P is a member of a component list, and that therefore the -- actions should be inserted outside the complete record -- declaration. elsif Nkind (Parent (P)) = N_Variant or else Nkind (Parent (P)) = N_Record_Definition then null; -- Do not insert freeze nodes within the loop generated for -- an aggregate, because they may be elaborated too late for -- subsequent use in the back end: within a package spec the -- loop is part of the elaboration procedure and is only -- elaborated during the second pass. -- If the loop comes from source, or the entity is local to the -- loop itself it must remain within. elsif Nkind (Parent (P)) = N_Loop_Statement and then not Comes_From_Source (Parent (P)) and then Nkind (First (Ins_Actions)) = N_Freeze_Entity and then Scope (Entity (First (Ins_Actions))) /= Current_Scope then null; -- Otherwise we can go ahead and do the insertion elsif P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); return; else Insert_List_Before_And_Analyze (P, Ins_Actions); return; end if; -- A special case, N_Raise_xxx_Error can act either as a statement -- or a subexpression. We tell the difference by looking at the -- Etype. It is set to Standard_Void_Type in the statement case. when N_Raise_xxx_Error => if Etype (P) = Standard_Void_Type then if P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); else Insert_List_Before_And_Analyze (P, Ins_Actions); end if; return; -- In the subexpression case, keep climbing else null; end if; -- If a component association appears within a loop created for -- an array aggregate, attach the actions to the association so -- they can be subsequently inserted within the loop. For other -- component associations insert outside of the aggregate. For -- an association that will generate a loop, its Loop_Actions -- attribute is already initialized (see exp_aggr.adb). -- The list of loop_actions can in turn generate additional ones, -- that are inserted before the associated node. If the associated -- node is outside the aggregate, the new actions are collected -- at the end of the loop actions, to respect the order in which -- they are to be elaborated. when N_Component_Association => if Nkind (Parent (P)) = N_Aggregate and then Present (Loop_Actions (P)) then if Is_Empty_List (Loop_Actions (P)) then Set_Loop_Actions (P, Ins_Actions); Analyze_List (Ins_Actions); else declare Decl : Node_Id; begin -- Check whether these actions were generated by a -- declaration that is part of the loop_ actions -- for the component_association. Decl := Assoc_Node; while Present (Decl) loop exit when Parent (Decl) = P and then Is_List_Member (Decl) and then List_Containing (Decl) = Loop_Actions (P); Decl := Parent (Decl); end loop; if Present (Decl) then Insert_List_Before_And_Analyze (Decl, Ins_Actions); else Insert_List_After_And_Analyze (Last (Loop_Actions (P)), Ins_Actions); end if; end; end if; return; else null; end if; -- Another special case, an attribute denoting a procedure call when N_Attribute_Reference => if Is_Procedure_Attribute_Name (Attribute_Name (P)) then if P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); else Insert_List_Before_And_Analyze (P, Ins_Actions); end if; return; -- In the subexpression case, keep climbing else null; end if; -- A contract node should not belong to the tree when N_Contract => raise Program_Error; -- For all other node types, keep climbing tree when N_Abortable_Part | N_Accept_Alternative | N_Access_Definition | N_Access_Function_Definition | N_Access_Procedure_Definition | N_Access_To_Object_Definition | N_Aggregate | N_Allocator | N_Aspect_Specification | N_Case_Expression | N_Case_Statement_Alternative | N_Character_Literal | N_Compilation_Unit | N_Compilation_Unit_Aux | N_Component_Clause | N_Component_Declaration | N_Component_Definition | N_Component_List | N_Constrained_Array_Definition | N_Decimal_Fixed_Point_Definition | N_Defining_Character_Literal | N_Defining_Identifier | N_Defining_Operator_Symbol | N_Defining_Program_Unit_Name | N_Delay_Alternative | N_Delta_Constraint | N_Derived_Type_Definition | N_Designator | N_Digits_Constraint | N_Discriminant_Association | N_Discriminant_Specification | N_Empty | N_Entry_Body_Formal_Part | N_Entry_Call_Alternative | N_Entry_Declaration | N_Entry_Index_Specification | N_Enumeration_Type_Definition | N_Error | N_Exception_Handler | N_Expanded_Name | N_Explicit_Dereference | N_Extension_Aggregate | N_Floating_Point_Definition | N_Formal_Decimal_Fixed_Point_Definition | N_Formal_Derived_Type_Definition | N_Formal_Discrete_Type_Definition | N_Formal_Floating_Point_Definition | N_Formal_Modular_Type_Definition | N_Formal_Ordinary_Fixed_Point_Definition | N_Formal_Package_Declaration | N_Formal_Private_Type_Definition | N_Formal_Incomplete_Type_Definition | N_Formal_Signed_Integer_Type_Definition | N_Function_Call | N_Function_Specification | N_Generic_Association | N_Handled_Sequence_Of_Statements | N_Identifier | N_In | N_Index_Or_Discriminant_Constraint | N_Indexed_Component | N_Integer_Literal | N_Iterator_Specification | N_Itype_Reference | N_Label | N_Loop_Parameter_Specification | N_Mod_Clause | N_Modular_Type_Definition | N_Not_In | N_Null | N_Op_Abs | N_Op_Add | N_Op_And | N_Op_Concat | N_Op_Divide | N_Op_Eq | N_Op_Expon | N_Op_Ge | N_Op_Gt | N_Op_Le | N_Op_Lt | N_Op_Minus | N_Op_Mod | N_Op_Multiply | N_Op_Ne | N_Op_Not | N_Op_Or | N_Op_Plus | N_Op_Rem | N_Op_Rotate_Left | N_Op_Rotate_Right | N_Op_Shift_Left | N_Op_Shift_Right | N_Op_Shift_Right_Arithmetic | N_Op_Subtract | N_Op_Xor | N_Operator_Symbol | N_Ordinary_Fixed_Point_Definition | N_Others_Choice | N_Package_Specification | N_Parameter_Association | N_Parameter_Specification | N_Pop_Constraint_Error_Label | N_Pop_Program_Error_Label | N_Pop_Storage_Error_Label | N_Pragma_Argument_Association | N_Procedure_Specification | N_Protected_Definition | N_Push_Constraint_Error_Label | N_Push_Program_Error_Label | N_Push_Storage_Error_Label | N_Qualified_Expression | N_Quantified_Expression | N_Range | N_Range_Constraint | N_Real_Literal | N_Real_Range_Specification | N_Record_Definition | N_Reference | N_SCIL_Dispatch_Table_Tag_Init | N_SCIL_Dispatching_Call | N_SCIL_Membership_Test | N_Selected_Component | N_Signed_Integer_Type_Definition | N_Single_Protected_Declaration | N_Slice | N_String_Literal | N_Subprogram_Info | N_Subtype_Indication | N_Subunit | N_Task_Definition | N_Terminate_Alternative | N_Triggering_Alternative | N_Type_Conversion | N_Unchecked_Expression | N_Unchecked_Type_Conversion | N_Unconstrained_Array_Definition | N_Unused_At_End | N_Unused_At_Start | N_Variant | N_Variant_Part | N_Validate_Unchecked_Conversion | N_With_Clause => null; end case; -- Make sure that inserted actions stay in the transient scope if P = Wrapped_Node then Store_Before_Actions_In_Scope (Ins_Actions); return; end if; -- If we fall through above tests, keep climbing tree N := P; if Nkind (Parent (N)) = N_Subunit then -- This is the proper body corresponding to a stub. Insertion must -- be done at the point of the stub, which is in the declarative -- part of the parent unit. P := Corresponding_Stub (Parent (N)); else P := Parent (N); end if; end loop; end Insert_Actions; -- Version with check(s) suppressed procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id; Suppress : Check_Id) is begin if Suppress = All_Checks then declare Svg : constant Suppress_Array := Scope_Suppress; begin Scope_Suppress := (others => True); Insert_Actions (Assoc_Node, Ins_Actions); Scope_Suppress := Svg; end; else declare Svg : constant Boolean := Scope_Suppress (Suppress); begin Scope_Suppress (Suppress) := True; Insert_Actions (Assoc_Node, Ins_Actions); Scope_Suppress (Suppress) := Svg; end; end if; end Insert_Actions; -------------------------- -- Insert_Actions_After -- -------------------------- procedure Insert_Actions_After (Assoc_Node : Node_Id; Ins_Actions : List_Id) is begin if Scope_Is_Transient and then Assoc_Node = Node_To_Be_Wrapped then Store_After_Actions_In_Scope (Ins_Actions); else Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions); end if; end Insert_Actions_After; --------------------------------- -- Insert_Library_Level_Action -- --------------------------------- procedure Insert_Library_Level_Action (N : Node_Id) is Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit)); begin Push_Scope (Cunit_Entity (Main_Unit)); -- ??? should this be Current_Sem_Unit instead of Main_Unit? if No (Actions (Aux)) then Set_Actions (Aux, New_List (N)); else Append (N, Actions (Aux)); end if; Analyze (N); Pop_Scope; end Insert_Library_Level_Action; ---------------------------------- -- Insert_Library_Level_Actions -- ---------------------------------- procedure Insert_Library_Level_Actions (L : List_Id) is Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit)); begin if Is_Non_Empty_List (L) then Push_Scope (Cunit_Entity (Main_Unit)); -- ??? should this be Current_Sem_Unit instead of Main_Unit? if No (Actions (Aux)) then Set_Actions (Aux, L); Analyze_List (L); else Insert_List_After_And_Analyze (Last (Actions (Aux)), L); end if; Pop_Scope; end if; end Insert_Library_Level_Actions; ---------------------- -- Inside_Init_Proc -- ---------------------- function Inside_Init_Proc return Boolean is S : Entity_Id; begin S := Current_Scope; while Present (S) and then S /= Standard_Standard loop if Is_Init_Proc (S) then return True; else S := Scope (S); end if; end loop; return False; end Inside_Init_Proc; ---------------------------- -- Is_All_Null_Statements -- ---------------------------- function Is_All_Null_Statements (L : List_Id) return Boolean is Stm : Node_Id; begin Stm := First (L); while Present (Stm) loop if Nkind (Stm) /= N_Null_Statement then return False; end if; Next (Stm); end loop; return True; end Is_All_Null_Statements; --------------------------------------------- -- Is_Displacement_Of_Ctrl_Function_Result -- --------------------------------------------- function Is_Displacement_Of_Ctrl_Function_Result (Obj_Id : Entity_Id) return Boolean is function Initialized_By_Ctrl_Function (N : Node_Id) return Boolean; -- Determine whether object declaration N is initialized by a controlled -- function call. function Is_Displace_Call (N : Node_Id) return Boolean; -- Determine whether a particular node is a call to Ada.Tags.Displace. -- The call might be nested within other actions such as conversions. ---------------------------------- -- Initialized_By_Ctrl_Function -- ---------------------------------- function Initialized_By_Ctrl_Function (N : Node_Id) return Boolean is Expr : constant Node_Id := Original_Node (Expression (N)); begin return Nkind (Expr) = N_Function_Call and then Needs_Finalization (Etype (Expr)); end Initialized_By_Ctrl_Function; ---------------------- -- Is_Displace_Call -- ---------------------- function Is_Displace_Call (N : Node_Id) return Boolean is Call : Node_Id := N; begin -- Strip various actions which may precede a call to Displace loop if Nkind (Call) = N_Explicit_Dereference then Call := Prefix (Call); elsif Nkind_In (Call, N_Type_Conversion, N_Unchecked_Type_Conversion) then Call := Expression (Call); else exit; end if; end loop; return Nkind (Call) = N_Function_Call and then Is_RTE (Entity (Name (Call)), RE_Displace); end Is_Displace_Call; -- Local variables Decl : constant Node_Id := Parent (Obj_Id); Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id)); Orig_Decl : constant Node_Id := Original_Node (Decl); -- Start of processing for Is_Displacement_Of_Ctrl_Function_Result begin -- Detect the following case: -- Obj : Class_Wide_Type := Function_Call (...); -- which is rewritten into: -- Temp : ... := Function_Call (...)'reference; -- Obj : Class_Wide_Type renames (... Ada.Tags.Displace (Temp)); -- when the return type of the function and the class-wide type require -- dispatch table pointer displacement. return Nkind (Decl) = N_Object_Renaming_Declaration and then Nkind (Orig_Decl) = N_Object_Declaration and then Comes_From_Source (Orig_Decl) and then Initialized_By_Ctrl_Function (Orig_Decl) and then Is_Class_Wide_Type (Obj_Typ) and then Is_Displace_Call (Renamed_Object (Obj_Id)); end Is_Displacement_Of_Ctrl_Function_Result; ------------------------------ -- Is_Finalizable_Transient -- ------------------------------ function Is_Finalizable_Transient (Decl : Node_Id; Rel_Node : Node_Id) return Boolean is Obj_Id : constant Entity_Id := Defining_Identifier (Decl); Obj_Typ : constant Entity_Id := Base_Type (Etype (Obj_Id)); Desig : Entity_Id := Obj_Typ; function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean; -- Determine whether transient object Trans_Id is initialized either -- by a function call which returns an access type or simply renames -- another pointer. function Initialized_By_Aliased_BIP_Func_Call (Trans_Id : Entity_Id) return Boolean; -- Determine whether transient object Trans_Id is initialized by a -- build-in-place function call where the BIPalloc parameter is of -- value 1 and BIPaccess is not null. This case creates an aliasing -- between the returned value and the value denoted by BIPaccess. function Is_Aliased (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean; -- Determine whether transient object Trans_Id has been renamed or -- aliased through 'reference in the statement list starting from -- First_Stmt. function Is_Allocated (Trans_Id : Entity_Id) return Boolean; -- Determine whether transient object Trans_Id is allocated on the heap function Is_Iterated_Container (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean; -- Determine whether transient object Trans_Id denotes a container which -- is in the process of being iterated in the statement list starting -- from First_Stmt. --------------------------- -- Initialized_By_Access -- --------------------------- function Initialized_By_Access (Trans_Id : Entity_Id) return Boolean is Expr : constant Node_Id := Expression (Parent (Trans_Id)); begin return Present (Expr) and then Nkind (Expr) /= N_Reference and then Is_Access_Type (Etype (Expr)); end Initialized_By_Access; ------------------------------------------ -- Initialized_By_Aliased_BIP_Func_Call -- ------------------------------------------ function Initialized_By_Aliased_BIP_Func_Call (Trans_Id : Entity_Id) return Boolean is Call : Node_Id := Expression (Parent (Trans_Id)); begin -- Build-in-place calls usually appear in 'reference format if Nkind (Call) = N_Reference then Call := Prefix (Call); end if; if Is_Build_In_Place_Function_Call (Call) then declare Access_Nam : Name_Id := No_Name; Access_OK : Boolean := False; Actual : Node_Id; Alloc_Nam : Name_Id := No_Name; Alloc_OK : Boolean := False; Formal : Node_Id; Func_Id : Entity_Id; Param : Node_Id; begin -- Examine all parameter associations of the function call Param := First (Parameter_Associations (Call)); while Present (Param) loop if Nkind (Param) = N_Parameter_Association and then Nkind (Selector_Name (Param)) = N_Identifier then Actual := Explicit_Actual_Parameter (Param); Formal := Selector_Name (Param); -- Construct the names of formals BIPaccess and BIPalloc -- using the function name retrieved from an arbitrary -- formal. if Access_Nam = No_Name and then Alloc_Nam = No_Name and then Present (Entity (Formal)) then Func_Id := Scope (Entity (Formal)); Access_Nam := New_External_Name (Chars (Func_Id), BIP_Formal_Suffix (BIP_Object_Access)); Alloc_Nam := New_External_Name (Chars (Func_Id), BIP_Formal_Suffix (BIP_Alloc_Form)); end if; -- A match for BIPaccess => Temp has been found if Chars (Formal) = Access_Nam and then Nkind (Actual) /= N_Null then Access_OK := True; end if; -- A match for BIPalloc => 1 has been found if Chars (Formal) = Alloc_Nam and then Nkind (Actual) = N_Integer_Literal and then Intval (Actual) = Uint_1 then Alloc_OK := True; end if; end if; Next (Param); end loop; return Access_OK and then Alloc_OK; end; end if; return False; end Initialized_By_Aliased_BIP_Func_Call; ---------------- -- Is_Aliased -- ---------------- function Is_Aliased (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean is function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id; -- Given an object renaming declaration, retrieve the entity of the -- renamed name. Return Empty if the renamed name is anything other -- than a variable or a constant. ------------------------- -- Find_Renamed_Object -- ------------------------- function Find_Renamed_Object (Ren_Decl : Node_Id) return Entity_Id is Ren_Obj : Node_Id := Empty; function Find_Object (N : Node_Id) return Traverse_Result; -- Try to detect an object which is either a constant or a -- variable. ----------------- -- Find_Object -- ----------------- function Find_Object (N : Node_Id) return Traverse_Result is begin -- Stop the search once a constant or a variable has been -- detected. if Nkind (N) = N_Identifier and then Present (Entity (N)) and then Ekind_In (Entity (N), E_Constant, E_Variable) then Ren_Obj := Entity (N); return Abandon; end if; return OK; end Find_Object; procedure Search is new Traverse_Proc (Find_Object); -- Local variables Typ : constant Entity_Id := Etype (Defining_Identifier (Ren_Decl)); -- Start of processing for Find_Renamed_Object begin -- Actions related to dispatching calls may appear as renamings of -- tags. Do not process this type of renaming because it does not -- use the actual value of the object. if not Is_RTE (Typ, RE_Tag_Ptr) then Search (Name (Ren_Decl)); end if; return Ren_Obj; end Find_Renamed_Object; -- Local variables Expr : Node_Id; Ren_Obj : Entity_Id; Stmt : Node_Id; -- Start of processing for Is_Aliased begin Stmt := First_Stmt; while Present (Stmt) loop if Nkind (Stmt) = N_Object_Declaration then Expr := Expression (Stmt); if Present (Expr) and then Nkind (Expr) = N_Reference and then Nkind (Prefix (Expr)) = N_Identifier and then Entity (Prefix (Expr)) = Trans_Id then return True; end if; elsif Nkind (Stmt) = N_Object_Renaming_Declaration then Ren_Obj := Find_Renamed_Object (Stmt); if Present (Ren_Obj) and then Ren_Obj = Trans_Id then return True; end if; end if; Next (Stmt); end loop; return False; end Is_Aliased; ------------------ -- Is_Allocated -- ------------------ function Is_Allocated (Trans_Id : Entity_Id) return Boolean is Expr : constant Node_Id := Expression (Parent (Trans_Id)); begin return Is_Access_Type (Etype (Trans_Id)) and then Present (Expr) and then Nkind (Expr) = N_Allocator; end Is_Allocated; --------------------------- -- Is_Iterated_Container -- --------------------------- function Is_Iterated_Container (Trans_Id : Entity_Id; First_Stmt : Node_Id) return Boolean is Aspect : Node_Id; Call : Node_Id; Iter : Entity_Id; Param : Node_Id; Stmt : Node_Id; Typ : Entity_Id; begin -- It is not possible to iterate over containers in non-Ada 2012 code if Ada_Version < Ada_2012 then return False; end if; Typ := Etype (Trans_Id); -- Handle access type created for secondary stack use if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); end if; -- Look for aspect Default_Iterator if Has_Aspects (Parent (Typ)) then Aspect := Find_Aspect (Typ, Aspect_Default_Iterator); if Present (Aspect) then Iter := Entity (Aspect); -- Examine the statements following the container object and -- look for a call to the default iterate routine where the -- first parameter is the transient. Such a call appears as: -- It : Access_To_CW_Iterator := -- Iterate (Tran_Id.all, ...)'reference; Stmt := First_Stmt; while Present (Stmt) loop -- Detect an object declaration which is initialized by a -- secondary stack function call. if Nkind (Stmt) = N_Object_Declaration and then Present (Expression (Stmt)) and then Nkind (Expression (Stmt)) = N_Reference and then Nkind (Prefix (Expression (Stmt))) = N_Function_Call then Call := Prefix (Expression (Stmt)); -- The call must invoke the default iterate routine of -- the container and the transient object must appear as -- the first actual parameter. Skip any calls whose names -- are not entities. if Is_Entity_Name (Name (Call)) and then Entity (Name (Call)) = Iter and then Present (Parameter_Associations (Call)) then Param := First (Parameter_Associations (Call)); if Nkind (Param) = N_Explicit_Dereference and then Entity (Prefix (Param)) = Trans_Id then return True; end if; end if; end if; Next (Stmt); end loop; end if; end if; return False; end Is_Iterated_Container; -- Start of processing for Is_Finalizable_Transient begin -- Handle access types if Is_Access_Type (Desig) then Desig := Available_View (Designated_Type (Desig)); end if; return Ekind_In (Obj_Id, E_Constant, E_Variable) and then Needs_Finalization (Desig) and then Requires_Transient_Scope (Desig) and then Nkind (Rel_Node) /= N_Simple_Return_Statement -- Do not consider renamed or 'reference-d transient objects because -- the act of renaming extends the object's lifetime. and then not Is_Aliased (Obj_Id, Decl) -- Do not consider transient objects allocated on the heap since -- they are attached to a finalization master. and then not Is_Allocated (Obj_Id) -- If the transient object is a pointer, check that it is not -- initialized by a function which returns a pointer or acts as a -- renaming of another pointer. and then (not Is_Access_Type (Obj_Typ) or else not Initialized_By_Access (Obj_Id)) -- Do not consider transient objects which act as indirect aliases -- of build-in-place function results. and then not Initialized_By_Aliased_BIP_Func_Call (Obj_Id) -- Do not consider conversions of tags to class-wide types and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id) -- Do not consider containers in the context of iterator loops. Such -- transient objects must exist for as long as the loop is around, -- otherwise any operation carried out by the iterator will fail. and then not Is_Iterated_Container (Obj_Id, Decl); end Is_Finalizable_Transient; --------------------------------- -- Is_Fully_Repped_Tagged_Type -- --------------------------------- function Is_Fully_Repped_Tagged_Type (T : Entity_Id) return Boolean is U : constant Entity_Id := Underlying_Type (T); Comp : Entity_Id; begin if No (U) or else not Is_Tagged_Type (U) then return False; elsif Has_Discriminants (U) then return False; elsif not Has_Specified_Layout (U) then return False; end if; -- Here we have a tagged type, see if it has any unlayed out fields -- other than a possible tag and parent fields. If so, we return False. Comp := First_Component (U); while Present (Comp) loop if not Is_Tag (Comp) and then Chars (Comp) /= Name_uParent and then No (Component_Clause (Comp)) then return False; else Next_Component (Comp); end if; end loop; -- All components are layed out return True; end Is_Fully_Repped_Tagged_Type; ---------------------------------- -- Is_Library_Level_Tagged_Type -- ---------------------------------- function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is begin return Is_Tagged_Type (Typ) and then Is_Library_Level_Entity (Typ); end Is_Library_Level_Tagged_Type; ---------------------------------- -- Is_Null_Access_BIP_Func_Call -- ---------------------------------- function Is_Null_Access_BIP_Func_Call (Expr : Node_Id) return Boolean is Call : Node_Id := Expr; begin -- Build-in-place calls usually appear in 'reference format if Nkind (Call) = N_Reference then Call := Prefix (Call); end if; if Nkind_In (Call, N_Qualified_Expression, N_Unchecked_Type_Conversion) then Call := Expression (Call); end if; if Is_Build_In_Place_Function_Call (Call) then declare Access_Nam : Name_Id := No_Name; Actual : Node_Id; Param : Node_Id; Formal : Node_Id; begin -- Examine all parameter associations of the function call Param := First (Parameter_Associations (Call)); while Present (Param) loop if Nkind (Param) = N_Parameter_Association and then Nkind (Selector_Name (Param)) = N_Identifier then Formal := Selector_Name (Param); Actual := Explicit_Actual_Parameter (Param); -- Construct the name of formal BIPaccess. It is much easier -- to extract the name of the function using an arbitrary -- formal's scope rather than the Name field of Call. if Access_Nam = No_Name and then Present (Entity (Formal)) then Access_Nam := New_External_Name (Chars (Scope (Entity (Formal))), BIP_Formal_Suffix (BIP_Object_Access)); end if; -- A match for BIPaccess => null has been found if Chars (Formal) = Access_Nam and then Nkind (Actual) = N_Null then return True; end if; end if; Next (Param); end loop; end; end if; return False; end Is_Null_Access_BIP_Func_Call; -------------------------- -- Is_Non_BIP_Func_Call -- -------------------------- function Is_Non_BIP_Func_Call (Expr : Node_Id) return Boolean is begin -- The expected call is of the format -- -- Func_Call'reference return Nkind (Expr) = N_Reference and then Nkind (Prefix (Expr)) = N_Function_Call and then not Is_Build_In_Place_Function_Call (Prefix (Expr)); end Is_Non_BIP_Func_Call; ---------------------------------- -- Is_Possibly_Unaligned_Object -- ---------------------------------- function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is T : constant Entity_Id := Etype (N); begin -- If renamed object, apply test to underlying object if Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N))); end if; -- Tagged and controlled types and aliased types are always aligned, as -- are concurrent types. if Is_Aliased (T) or else Has_Controlled_Component (T) or else Is_Concurrent_Type (T) or else Is_Tagged_Type (T) or else Is_Controlled (T) then return False; end if; -- If this is an element of a packed array, may be unaligned if Is_Ref_To_Bit_Packed_Array (N) then return True; end if; -- Case of indexed component reference: test whether prefix is unaligned if Nkind (N) = N_Indexed_Component then return Is_Possibly_Unaligned_Object (Prefix (N)); -- Case of selected component reference elsif Nkind (N) = N_Selected_Component then declare P : constant Node_Id := Prefix (N); C : constant Entity_Id := Entity (Selector_Name (N)); M : Nat; S : Nat; begin -- If component reference is for an array with non-static bounds, -- then it is always aligned: we can only process unaligned arrays -- with static bounds (more precisely compile time known bounds). if Is_Array_Type (T) and then not Compile_Time_Known_Bounds (T) then return False; end if; -- If component is aliased, it is definitely properly aligned if Is_Aliased (C) then return False; end if; -- If component is for a type implemented as a scalar, and the -- record is packed, and the component is other than the first -- component of the record, then the component may be unaligned. if Is_Packed (Etype (P)) and then Represented_As_Scalar (Etype (C)) and then First_Entity (Scope (C)) /= C then return True; end if; -- Compute maximum possible alignment for T -- If alignment is known, then that settles things if Known_Alignment (T) then M := UI_To_Int (Alignment (T)); -- If alignment is not known, tentatively set max alignment else M := Ttypes.Maximum_Alignment; -- We can reduce this if the Esize is known since the default -- alignment will never be more than the smallest power of 2 -- that does not exceed this Esize value. if Known_Esize (T) then S := UI_To_Int (Esize (T)); while (M / 2) >= S loop M := M / 2; end loop; end if; end if; -- The following code is historical, it used to be present but it -- is too cautious, because the front-end does not know the proper -- default alignments for the target. Also, if the alignment is -- not known, the front end can't know in any case! If a copy is -- needed, the back-end will take care of it. This whole section -- including this comment can be removed later ??? -- If the component reference is for a record that has a specified -- alignment, and we either know it is too small, or cannot tell, -- then the component may be unaligned. -- What is the following commented out code ??? -- if Known_Alignment (Etype (P)) -- and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment -- and then M > Alignment (Etype (P)) -- then -- return True; -- end if; -- Case of component clause present which may specify an -- unaligned position. if Present (Component_Clause (C)) then -- Otherwise we can do a test to make sure that the actual -- start position in the record, and the length, are both -- consistent with the required alignment. If not, we know -- that we are unaligned. declare Align_In_Bits : constant Nat := M * System_Storage_Unit; begin if Component_Bit_Offset (C) mod Align_In_Bits /= 0 or else Esize (C) mod Align_In_Bits /= 0 then return True; end if; end; end if; -- Otherwise, for a component reference, test prefix return Is_Possibly_Unaligned_Object (P); end; -- If not a component reference, must be aligned else return False; end if; end Is_Possibly_Unaligned_Object; --------------------------------- -- Is_Possibly_Unaligned_Slice -- --------------------------------- function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is begin -- Go to renamed object if Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N))); end if; -- The reference must be a slice if Nkind (N) /= N_Slice then return False; end if; -- Always assume the worst for a nested record component with a -- component clause, which gigi/gcc does not appear to handle well. -- It is not clear why this special test is needed at all ??? if Nkind (Prefix (N)) = N_Selected_Component and then Nkind (Prefix (Prefix (N))) = N_Selected_Component and then Present (Component_Clause (Entity (Selector_Name (Prefix (N))))) then return True; end if; -- We only need to worry if the target has strict alignment if not Target_Strict_Alignment then return False; end if; -- If it is a slice, then look at the array type being sliced declare Sarr : constant Node_Id := Prefix (N); -- Prefix of the slice, i.e. the array being sliced Styp : constant Entity_Id := Etype (Prefix (N)); -- Type of the array being sliced Pref : Node_Id; Ptyp : Entity_Id; begin -- The problems arise if the array object that is being sliced -- is a component of a record or array, and we cannot guarantee -- the alignment of the array within its containing object. -- To investigate this, we look at successive prefixes to see -- if we have a worrisome indexed or selected component. Pref := Sarr; loop -- Case of array is part of an indexed component reference if Nkind (Pref) = N_Indexed_Component then Ptyp := Etype (Prefix (Pref)); -- The only problematic case is when the array is packed, in -- which case we really know nothing about the alignment of -- individual components. if Is_Bit_Packed_Array (Ptyp) then return True; end if; -- Case of array is part of a selected component reference elsif Nkind (Pref) = N_Selected_Component then Ptyp := Etype (Prefix (Pref)); -- We are definitely in trouble if the record in question -- has an alignment, and either we know this alignment is -- inconsistent with the alignment of the slice, or we don't -- know what the alignment of the slice should be. if Known_Alignment (Ptyp) and then (Unknown_Alignment (Styp) or else Alignment (Styp) > Alignment (Ptyp)) then return True; end if; -- We are in potential trouble if the record type is packed. -- We could special case when we know that the array is the -- first component, but that's not such a simple case ??? if Is_Packed (Ptyp) then return True; end if; -- We are in trouble if there is a component clause, and -- either we do not know the alignment of the slice, or -- the alignment of the slice is inconsistent with the -- bit position specified by the component clause. declare Field : constant Entity_Id := Entity (Selector_Name (Pref)); begin if Present (Component_Clause (Field)) and then (Unknown_Alignment (Styp) or else (Component_Bit_Offset (Field) mod (System_Storage_Unit * Alignment (Styp))) /= 0) then return True; end if; end; -- For cases other than selected or indexed components we know we -- are OK, since no issues arise over alignment. else return False; end if; -- We processed an indexed component or selected component -- reference that looked safe, so keep checking prefixes. Pref := Prefix (Pref); end loop; end; end Is_Possibly_Unaligned_Slice; ------------------------------- -- Is_Related_To_Func_Return -- ------------------------------- function Is_Related_To_Func_Return (Id : Entity_Id) return Boolean is Expr : constant Node_Id := Related_Expression (Id); begin return Present (Expr) and then Nkind (Expr) = N_Explicit_Dereference and then Nkind (Parent (Expr)) = N_Simple_Return_Statement; end Is_Related_To_Func_Return; -------------------------------- -- Is_Ref_To_Bit_Packed_Array -- -------------------------------- function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is Result : Boolean; Expr : Node_Id; begin if Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N))); end if; if Nkind (N) = N_Indexed_Component or else Nkind (N) = N_Selected_Component then if Is_Bit_Packed_Array (Etype (Prefix (N))) then Result := True; else Result := Is_Ref_To_Bit_Packed_Array (Prefix (N)); end if; if Result and then Nkind (N) = N_Indexed_Component then Expr := First (Expressions (N)); while Present (Expr) loop Force_Evaluation (Expr); Next (Expr); end loop; end if; return Result; else return False; end if; end Is_Ref_To_Bit_Packed_Array; -------------------------------- -- Is_Ref_To_Bit_Packed_Slice -- -------------------------------- function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is begin if Nkind (N) = N_Type_Conversion then return Is_Ref_To_Bit_Packed_Slice (Expression (N)); elsif Is_Entity_Name (N) and then Is_Object (Entity (N)) and then Present (Renamed_Object (Entity (N))) then return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N))); elsif Nkind (N) = N_Slice and then Is_Bit_Packed_Array (Etype (Prefix (N))) then return True; elsif Nkind (N) = N_Indexed_Component or else Nkind (N) = N_Selected_Component then return Is_Ref_To_Bit_Packed_Slice (Prefix (N)); else return False; end if; end Is_Ref_To_Bit_Packed_Slice; ----------------------- -- Is_Renamed_Object -- ----------------------- function Is_Renamed_Object (N : Node_Id) return Boolean is Pnod : constant Node_Id := Parent (N); Kind : constant Node_Kind := Nkind (Pnod); begin if Kind = N_Object_Renaming_Declaration then return True; elsif Nkind_In (Kind, N_Indexed_Component, N_Selected_Component) then return Is_Renamed_Object (Pnod); else return False; end if; end Is_Renamed_Object; ------------------------------------- -- Is_Tag_To_Class_Wide_Conversion -- ------------------------------------- function Is_Tag_To_Class_Wide_Conversion (Obj_Id : Entity_Id) return Boolean is Expr : constant Node_Id := Expression (Parent (Obj_Id)); begin return Is_Class_Wide_Type (Etype (Obj_Id)) and then Present (Expr) and then Nkind (Expr) = N_Unchecked_Type_Conversion and then Etype (Expression (Expr)) = RTE (RE_Tag); end Is_Tag_To_Class_Wide_Conversion; ---------------------------- -- Is_Untagged_Derivation -- ---------------------------- function Is_Untagged_Derivation (T : Entity_Id) return Boolean is begin return (not Is_Tagged_Type (T) and then Is_Derived_Type (T)) or else (Is_Private_Type (T) and then Present (Full_View (T)) and then not Is_Tagged_Type (Full_View (T)) and then Is_Derived_Type (Full_View (T)) and then Etype (Full_View (T)) /= T); end Is_Untagged_Derivation; --------------------------- -- Is_Volatile_Reference -- --------------------------- function Is_Volatile_Reference (N : Node_Id) return Boolean is begin if Nkind (N) in N_Has_Etype and then Present (Etype (N)) and then Treat_As_Volatile (Etype (N)) then return True; elsif Is_Entity_Name (N) then return Treat_As_Volatile (Entity (N)); elsif Nkind (N) = N_Slice then return Is_Volatile_Reference (Prefix (N)); elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then if (Is_Entity_Name (Prefix (N)) and then Has_Volatile_Components (Entity (Prefix (N)))) or else (Present (Etype (Prefix (N))) and then Has_Volatile_Components (Etype (Prefix (N)))) then return True; else return Is_Volatile_Reference (Prefix (N)); end if; else return False; end if; end Is_Volatile_Reference; -------------------------- -- Is_VM_By_Copy_Actual -- -------------------------- function Is_VM_By_Copy_Actual (N : Node_Id) return Boolean is begin return VM_Target /= No_VM and then (Nkind (N) = N_Slice or else (Nkind (N) = N_Identifier and then Present (Renamed_Object (Entity (N))) and then Nkind (Renamed_Object (Entity (N))) = N_Slice)); end Is_VM_By_Copy_Actual; -------------------- -- Kill_Dead_Code -- -------------------- procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is W : Boolean := Warn; -- Set False if warnings suppressed begin if Present (N) then Remove_Warning_Messages (N); -- Generate warning if appropriate if W then -- We suppress the warning if this code is under control of an -- if statement, whose condition is a simple identifier, and -- either we are in an instance, or warnings off is set for this -- identifier. The reason for killing it in the instance case is -- that it is common and reasonable for code to be deleted in -- instances for various reasons. if Nkind (Parent (N)) = N_If_Statement then declare C : constant Node_Id := Condition (Parent (N)); begin if Nkind (C) = N_Identifier and then (In_Instance or else (Present (Entity (C)) and then Has_Warnings_Off (Entity (C)))) then W := False; end if; end; end if; -- Generate warning if not suppressed if W then Error_Msg_F ("?this code can never be executed and has been deleted!", N); end if; end if; -- Recurse into block statements and bodies to process declarations -- and statements. if Nkind (N) = N_Block_Statement or else Nkind (N) = N_Subprogram_Body or else Nkind (N) = N_Package_Body then Kill_Dead_Code (Declarations (N), False); Kill_Dead_Code (Statements (Handled_Statement_Sequence (N))); if Nkind (N) = N_Subprogram_Body then Set_Is_Eliminated (Defining_Entity (N)); end if; elsif Nkind (N) = N_Package_Declaration then Kill_Dead_Code (Visible_Declarations (Specification (N))); Kill_Dead_Code (Private_Declarations (Specification (N))); -- ??? After this point, Delete_Tree has been called on all -- declarations in Specification (N), so references to entities -- therein look suspicious. declare E : Entity_Id := First_Entity (Defining_Entity (N)); begin while Present (E) loop if Ekind (E) = E_Operator then Set_Is_Eliminated (E); end if; Next_Entity (E); end loop; end; -- Recurse into composite statement to kill individual statements in -- particular instantiations. elsif Nkind (N) = N_If_Statement then Kill_Dead_Code (Then_Statements (N)); Kill_Dead_Code (Elsif_Parts (N)); Kill_Dead_Code (Else_Statements (N)); elsif Nkind (N) = N_Loop_Statement then Kill_Dead_Code (Statements (N)); elsif Nkind (N) = N_Case_Statement then declare Alt : Node_Id; begin Alt := First (Alternatives (N)); while Present (Alt) loop Kill_Dead_Code (Statements (Alt)); Next (Alt); end loop; end; elsif Nkind (N) = N_Case_Statement_Alternative then Kill_Dead_Code (Statements (N)); -- Deal with dead instances caused by deleting instantiations elsif Nkind (N) in N_Generic_Instantiation then Remove_Dead_Instance (N); end if; end if; end Kill_Dead_Code; -- Case where argument is a list of nodes to be killed procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is N : Node_Id; W : Boolean; begin W := Warn; if Is_Non_Empty_List (L) then N := First (L); while Present (N) loop Kill_Dead_Code (N, W); W := False; Next (N); end loop; end if; end Kill_Dead_Code; ------------------------ -- Known_Non_Negative -- ------------------------ function Known_Non_Negative (Opnd : Node_Id) return Boolean is begin if Is_OK_Static_Expression (Opnd) and then Expr_Value (Opnd) >= 0 then return True; else declare Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd)); begin return Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0; end; end if; end Known_Non_Negative; -------------------- -- Known_Non_Null -- -------------------- function Known_Non_Null (N : Node_Id) return Boolean is begin -- Checks for case where N is an entity reference if Is_Entity_Name (N) and then Present (Entity (N)) then declare E : constant Entity_Id := Entity (N); Op : Node_Kind; Val : Node_Id; begin -- First check if we are in decisive conditional Get_Current_Value_Condition (N, Op, Val); if Known_Null (Val) then if Op = N_Op_Eq then return False; elsif Op = N_Op_Ne then return True; end if; end if; -- If OK to do replacement, test Is_Known_Non_Null flag if OK_To_Do_Constant_Replacement (E) then return Is_Known_Non_Null (E); -- Otherwise if not safe to do replacement, then say so else return False; end if; end; -- True if access attribute elsif Nkind (N) = N_Attribute_Reference and then (Attribute_Name (N) = Name_Access or else Attribute_Name (N) = Name_Unchecked_Access or else Attribute_Name (N) = Name_Unrestricted_Access) then return True; -- True if allocator elsif Nkind (N) = N_Allocator then return True; -- For a conversion, true if expression is known non-null elsif Nkind (N) = N_Type_Conversion then return Known_Non_Null (Expression (N)); -- Above are all cases where the value could be determined to be -- non-null. In all other cases, we don't know, so return False. else return False; end if; end Known_Non_Null; ---------------- -- Known_Null -- ---------------- function Known_Null (N : Node_Id) return Boolean is begin -- Checks for case where N is an entity reference if Is_Entity_Name (N) and then Present (Entity (N)) then declare E : constant Entity_Id := Entity (N); Op : Node_Kind; Val : Node_Id; begin -- Constant null value is for sure null if Ekind (E) = E_Constant and then Known_Null (Constant_Value (E)) then return True; end if; -- First check if we are in decisive conditional Get_Current_Value_Condition (N, Op, Val); if Known_Null (Val) then if Op = N_Op_Eq then return True; elsif Op = N_Op_Ne then return False; end if; end if; -- If OK to do replacement, test Is_Known_Null flag if OK_To_Do_Constant_Replacement (E) then return Is_Known_Null (E); -- Otherwise if not safe to do replacement, then say so else return False; end if; end; -- True if explicit reference to null elsif Nkind (N) = N_Null then return True; -- For a conversion, true if expression is known null elsif Nkind (N) = N_Type_Conversion then return Known_Null (Expression (N)); -- Above are all cases where the value could be determined to be null. -- In all other cases, we don't know, so return False. else return False; end if; end Known_Null; ----------------------------- -- Make_CW_Equivalent_Type -- ----------------------------- -- Create a record type used as an equivalent of any member of the class -- which takes its size from exp. -- Generate the following code: -- type Equiv_T is record -- _parent : T (List of discriminant constraints taken from Exp); -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8); -- end Equiv_T; -- -- ??? Note that this type does not guarantee same alignment as all -- derived types function Make_CW_Equivalent_Type (T : Entity_Id; E : Node_Id) return Entity_Id is Loc : constant Source_Ptr := Sloc (E); Root_Typ : constant Entity_Id := Root_Type (T); List_Def : constant List_Id := Empty_List; Comp_List : constant List_Id := New_List; Equiv_Type : Entity_Id; Range_Type : Entity_Id; Str_Type : Entity_Id; Constr_Root : Entity_Id; Sizexpr : Node_Id; begin -- If the root type is already constrained, there are no discriminants -- in the expression. if not Has_Discriminants (Root_Typ) or else Is_Constrained (Root_Typ) then Constr_Root := Root_Typ; else Constr_Root := Make_Temporary (Loc, 'R'); -- subtype cstr__n is T (List of discr constraints taken from Exp) Append_To (List_Def, Make_Subtype_Declaration (Loc, Defining_Identifier => Constr_Root, Subtype_Indication => Make_Subtype_From_Expr (E, Root_Typ))); end if; -- Generate the range subtype declaration Range_Type := Make_Temporary (Loc, 'G'); if not Is_Interface (Root_Typ) then -- subtype rg__xx is -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit Sizexpr := Make_Op_Subtract (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)), Attribute_Name => Name_Size), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Constr_Root, Loc), Attribute_Name => Name_Object_Size)); else -- subtype rg__xx is -- Storage_Offset range 1 .. Expr'size / Storage_Unit Sizexpr := Make_Attribute_Reference (Loc, Prefix => OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)), Attribute_Name => Name_Size); end if; Set_Paren_Count (Sizexpr, 1); Append_To (List_Def, Make_Subtype_Declaration (Loc, Defining_Identifier => Range_Type, Subtype_Indication => Make_Subtype_Indication (Loc, Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc), Constraint => Make_Range_Constraint (Loc, Range_Expression => Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => Make_Op_Divide (Loc, Left_Opnd => Sizexpr, Right_Opnd => Make_Integer_Literal (Loc, Intval => System_Storage_Unit))))))); -- subtype str__nn is Storage_Array (rg__x); Str_Type := Make_Temporary (Loc, 'S'); Append_To (List_Def, Make_Subtype_Declaration (Loc, Defining_Identifier => Str_Type, Subtype_Indication => Make_Subtype_Indication (Loc, Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List (New_Reference_To (Range_Type, Loc)))))); -- type Equiv_T is record -- [ _parent : Tnn; ] -- E : Str_Type; -- end Equiv_T; Equiv_Type := Make_Temporary (Loc, 'T'); Set_Ekind (Equiv_Type, E_Record_Type); Set_Parent_Subtype (Equiv_Type, Constr_Root); -- Set Is_Class_Wide_Equivalent_Type very early to trigger the special -- treatment for this type. In particular, even though _parent's type -- is a controlled type or contains controlled components, we do not -- want to set Has_Controlled_Component on it to avoid making it gain -- an unwanted _controller component. Set_Is_Class_Wide_Equivalent_Type (Equiv_Type); if not Is_Interface (Root_Typ) then Append_To (Comp_List, Make_Component_Declaration (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_uParent), Component_Definition => Make_Component_Definition (Loc, Aliased_Present => False, Subtype_Indication => New_Reference_To (Constr_Root, Loc)))); end if; Append_To (Comp_List, Make_Component_Declaration (Loc, Defining_Identifier => Make_Temporary (Loc, 'C'), Component_Definition => Make_Component_Definition (Loc, Aliased_Present => False, Subtype_Indication => New_Reference_To (Str_Type, Loc)))); Append_To (List_Def, Make_Full_Type_Declaration (Loc, Defining_Identifier => Equiv_Type, Type_Definition => Make_Record_Definition (Loc, Component_List => Make_Component_List (Loc, Component_Items => Comp_List, Variant_Part => Empty)))); -- Suppress all checks during the analysis of the expanded code to avoid -- the generation of spurious warnings under ZFP run-time. Insert_Actions (E, List_Def, Suppress => All_Checks); return Equiv_Type; end Make_CW_Equivalent_Type; ------------------------- -- Make_Invariant_Call -- ------------------------- function Make_Invariant_Call (Expr : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Expr); Typ : constant Entity_Id := Etype (Expr); begin pragma Assert (Has_Invariants (Typ) and then Present (Invariant_Procedure (Typ))); if Check_Enabled (Name_Invariant) or else Check_Enabled (Name_Assertion) then return Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of (Invariant_Procedure (Typ), Loc), Parameter_Associations => New_List (Relocate_Node (Expr))); else return Make_Null_Statement (Loc); end if; end Make_Invariant_Call; ------------------------ -- Make_Literal_Range -- ------------------------ function Make_Literal_Range (Loc : Source_Ptr; Literal_Typ : Entity_Id) return Node_Id is Lo : constant Node_Id := New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ)); Index : constant Entity_Id := Etype (Lo); Hi : Node_Id; Length_Expr : constant Node_Id := Make_Op_Subtract (Loc, Left_Opnd => Make_Integer_Literal (Loc, Intval => String_Literal_Length (Literal_Typ)), Right_Opnd => Make_Integer_Literal (Loc, 1)); begin Set_Analyzed (Lo, False); if Is_Integer_Type (Index) then Hi := Make_Op_Add (Loc, Left_Opnd => New_Copy_Tree (Lo), Right_Opnd => Length_Expr); else Hi := Make_Attribute_Reference (Loc, Attribute_Name => Name_Val, Prefix => New_Occurrence_Of (Index, Loc), Expressions => New_List ( Make_Op_Add (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Pos, Prefix => New_Occurrence_Of (Index, Loc), Expressions => New_List (New_Copy_Tree (Lo))), Right_Opnd => Length_Expr))); end if; return Make_Range (Loc, Low_Bound => Lo, High_Bound => Hi); end Make_Literal_Range; -------------------------- -- Make_Non_Empty_Check -- -------------------------- function Make_Non_Empty_Check (Loc : Source_Ptr; N : Node_Id) return Node_Id is begin return Make_Op_Ne (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Attribute_Name => Name_Length, Prefix => Duplicate_Subexpr_No_Checks (N, Name_Req => True)), Right_Opnd => Make_Integer_Literal (Loc, 0)); end Make_Non_Empty_Check; ------------------------- -- Make_Predicate_Call -- ------------------------- function Make_Predicate_Call (Typ : Entity_Id; Expr : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Expr); begin pragma Assert (Present (Predicate_Function (Typ))); return Make_Function_Call (Loc, Name => New_Occurrence_Of (Predicate_Function (Typ), Loc), Parameter_Associations => New_List (Relocate_Node (Expr))); end Make_Predicate_Call; -------------------------- -- Make_Predicate_Check -- -------------------------- function Make_Predicate_Check (Typ : Entity_Id; Expr : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Expr); begin return Make_Pragma (Loc, Pragma_Identifier => Make_Identifier (Loc, Name_Check), Pragma_Argument_Associations => New_List ( Make_Pragma_Argument_Association (Loc, Expression => Make_Identifier (Loc, Name_Predicate)), Make_Pragma_Argument_Association (Loc, Expression => Make_Predicate_Call (Typ, Expr)))); end Make_Predicate_Check; ---------------------------- -- Make_Subtype_From_Expr -- ---------------------------- -- 1. If Expr is an unconstrained array expression, creates -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n)) -- 2. If Expr is a unconstrained discriminated type expression, creates -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n) -- 3. If Expr is class-wide, creates an implicit class wide subtype function Make_Subtype_From_Expr (E : Node_Id; Unc_Typ : Entity_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (E); List_Constr : constant List_Id := New_List; D : Entity_Id; Full_Subtyp : Entity_Id; Priv_Subtyp : Entity_Id; Utyp : Entity_Id; Full_Exp : Node_Id; begin if Is_Private_Type (Unc_Typ) and then Has_Unknown_Discriminants (Unc_Typ) then -- Prepare the subtype completion, Go to base type to -- find underlying type, because the type may be a generic -- actual or an explicit subtype. Utyp := Underlying_Type (Base_Type (Unc_Typ)); Full_Subtyp := Make_Temporary (Loc, 'C'); Full_Exp := Unchecked_Convert_To (Utyp, Duplicate_Subexpr_No_Checks (E)); Set_Parent (Full_Exp, Parent (E)); Priv_Subtyp := Make_Temporary (Loc, 'P'); Insert_Action (E, Make_Subtype_Declaration (Loc, Defining_Identifier => Full_Subtyp, Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp))); -- Define the dummy private subtype Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ))); Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ)); Set_Scope (Priv_Subtyp, Full_Subtyp); Set_Is_Constrained (Priv_Subtyp); Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ)); Set_Is_Itype (Priv_Subtyp); Set_Associated_Node_For_Itype (Priv_Subtyp, E); if Is_Tagged_Type (Priv_Subtyp) then Set_Class_Wide_Type (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ)); Set_Direct_Primitive_Operations (Priv_Subtyp, Direct_Primitive_Operations (Unc_Typ)); end if; Set_Full_View (Priv_Subtyp, Full_Subtyp); return New_Reference_To (Priv_Subtyp, Loc); elsif Is_Array_Type (Unc_Typ) then for J in 1 .. Number_Dimensions (Unc_Typ) loop Append_To (List_Constr, Make_Range (Loc, Low_Bound => Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (E), Attribute_Name => Name_First, Expressions => New_List ( Make_Integer_Literal (Loc, J))), High_Bound => Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (E), Attribute_Name => Name_Last, Expressions => New_List ( Make_Integer_Literal (Loc, J))))); end loop; elsif Is_Class_Wide_Type (Unc_Typ) then declare CW_Subtype : Entity_Id; EQ_Typ : Entity_Id := Empty; begin -- A class-wide equivalent type is not needed when VM_Target -- because the VM back-ends handle the class-wide object -- initialization itself (and doesn't need or want the -- additional intermediate type to handle the assignment). if Expander_Active and then Tagged_Type_Expansion then -- If this is the class_wide type of a completion that is a -- record subtype, set the type of the class_wide type to be -- the full base type, for use in the expanded code for the -- equivalent type. Should this be done earlier when the -- completion is analyzed ??? if Is_Private_Type (Etype (Unc_Typ)) and then Ekind (Full_View (Etype (Unc_Typ))) = E_Record_Subtype then Set_Etype (Unc_Typ, Base_Type (Full_View (Etype (Unc_Typ)))); end if; EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E); end if; CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E); Set_Equivalent_Type (CW_Subtype, EQ_Typ); Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ)); return New_Occurrence_Of (CW_Subtype, Loc); end; -- Indefinite record type with discriminants else D := First_Discriminant (Unc_Typ); while Present (D) loop Append_To (List_Constr, Make_Selected_Component (Loc, Prefix => Duplicate_Subexpr_No_Checks (E), Selector_Name => New_Reference_To (D, Loc))); Next_Discriminant (D); end loop; end if; return Make_Subtype_Indication (Loc, Subtype_Mark => New_Reference_To (Unc_Typ, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => List_Constr)); end Make_Subtype_From_Expr; ----------------------------- -- May_Generate_Large_Temp -- ----------------------------- -- At the current time, the only types that we return False for (i.e. where -- we decide we know they cannot generate large temps) are ones where we -- know the size is 256 bits or less at compile time, and we are still not -- doing a thorough job on arrays and records ??? function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is begin if not Size_Known_At_Compile_Time (Typ) then return False; elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then return False; elsif Is_Array_Type (Typ) and then Present (Packed_Array_Type (Typ)) then return May_Generate_Large_Temp (Packed_Array_Type (Typ)); -- We could do more here to find other small types ??? else return True; end if; end May_Generate_Large_Temp; ------------------------ -- Needs_Finalization -- ------------------------ function Needs_Finalization (T : Entity_Id) return Boolean is function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean; -- If type is not frozen yet, check explicitly among its components, -- because the Has_Controlled_Component flag is not necessarily set. ----------------------------------- -- Has_Some_Controlled_Component -- ----------------------------------- function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean is Comp : Entity_Id; begin if Has_Controlled_Component (Rec) then return True; elsif not Is_Frozen (Rec) then if Is_Record_Type (Rec) then Comp := First_Entity (Rec); while Present (Comp) loop if not Is_Type (Comp) and then Needs_Finalization (Etype (Comp)) then return True; end if; Next_Entity (Comp); end loop; return False; elsif Is_Array_Type (Rec) then return Needs_Finalization (Component_Type (Rec)); else return Has_Controlled_Component (Rec); end if; else return False; end if; end Has_Some_Controlled_Component; -- Start of processing for Needs_Finalization begin -- Certain run-time configurations and targets do not provide support -- for controlled types. if Restriction_Active (No_Finalization) then return False; -- C, C++, CIL and Java types are not considered controlled. It is -- assumed that the non-Ada side will handle their clean up. elsif Convention (T) = Convention_C or else Convention (T) = Convention_CIL or else Convention (T) = Convention_CPP or else Convention (T) = Convention_Java then return False; else -- Class-wide types are treated as controlled because derivations -- from the root type can introduce controlled components. return Is_Class_Wide_Type (T) or else Is_Controlled (T) or else Has_Controlled_Component (T) or else Has_Some_Controlled_Component (T) or else (Is_Concurrent_Type (T) and then Present (Corresponding_Record_Type (T)) and then Needs_Finalization (Corresponding_Record_Type (T))); end if; end Needs_Finalization; ---------------------------- -- Needs_Constant_Address -- ---------------------------- function Needs_Constant_Address (Decl : Node_Id; Typ : Entity_Id) return Boolean is begin -- If we have no initialization of any kind, then we don't need to place -- any restrictions on the address clause, because the object will be -- elaborated after the address clause is evaluated. This happens if the -- declaration has no initial expression, or the type has no implicit -- initialization, or the object is imported. -- The same holds for all initialized scalar types and all access types. -- Packed bit arrays of size up to 64 are represented using a modular -- type with an initialization (to zero) and can be processed like other -- initialized scalar types. -- If the type is controlled, code to attach the object to a -- finalization chain is generated at the point of declaration, and -- therefore the elaboration of the object cannot be delayed: the -- address expression must be a constant. if No (Expression (Decl)) and then not Needs_Finalization (Typ) and then (not Has_Non_Null_Base_Init_Proc (Typ) or else Is_Imported (Defining_Identifier (Decl))) then return False; elsif (Present (Expression (Decl)) and then Is_Scalar_Type (Typ)) or else Is_Access_Type (Typ) or else (Is_Bit_Packed_Array (Typ) and then Is_Modular_Integer_Type (Packed_Array_Type (Typ))) then return False; else -- Otherwise, we require the address clause to be constant because -- the call to the initialization procedure (or the attach code) has -- to happen at the point of the declaration. -- Actually the IP call has been moved to the freeze actions anyway, -- so maybe we can relax this restriction??? return True; end if; end Needs_Constant_Address; ---------------------------- -- New_Class_Wide_Subtype -- ---------------------------- function New_Class_Wide_Subtype (CW_Typ : Entity_Id; N : Node_Id) return Entity_Id is Res : constant Entity_Id := Create_Itype (E_Void, N); Res_Name : constant Name_Id := Chars (Res); Res_Scope : constant Entity_Id := Scope (Res); begin Copy_Node (CW_Typ, Res); Set_Comes_From_Source (Res, False); Set_Sloc (Res, Sloc (N)); Set_Is_Itype (Res); Set_Associated_Node_For_Itype (Res, N); Set_Is_Public (Res, False); -- By default, may be changed below. Set_Public_Status (Res); Set_Chars (Res, Res_Name); Set_Scope (Res, Res_Scope); Set_Ekind (Res, E_Class_Wide_Subtype); Set_Next_Entity (Res, Empty); Set_Etype (Res, Base_Type (CW_Typ)); Set_Is_Frozen (Res, False); Set_Freeze_Node (Res, Empty); return (Res); end New_Class_Wide_Subtype; -------------------------------- -- Non_Limited_Designated_Type -- --------------------------------- function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is Desig : constant Entity_Id := Designated_Type (T); begin if Ekind (Desig) = E_Incomplete_Type and then Present (Non_Limited_View (Desig)) then return Non_Limited_View (Desig); else return Desig; end if; end Non_Limited_Designated_Type; ----------------------------------- -- OK_To_Do_Constant_Replacement -- ----------------------------------- function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is ES : constant Entity_Id := Scope (E); CS : Entity_Id; begin -- Do not replace statically allocated objects, because they may be -- modified outside the current scope. if Is_Statically_Allocated (E) then return False; -- Do not replace aliased or volatile objects, since we don't know what -- else might change the value. elsif Is_Aliased (E) or else Treat_As_Volatile (E) then return False; -- Debug flag -gnatdM disconnects this optimization elsif Debug_Flag_MM then return False; -- Otherwise check scopes else CS := Current_Scope; loop -- If we are in right scope, replacement is safe if CS = ES then return True; -- Packages do not affect the determination of safety elsif Ekind (CS) = E_Package then exit when CS = Standard_Standard; CS := Scope (CS); -- Blocks do not affect the determination of safety elsif Ekind (CS) = E_Block then CS := Scope (CS); -- Loops do not affect the determination of safety. Note that we -- kill all current values on entry to a loop, so we are just -- talking about processing within a loop here. elsif Ekind (CS) = E_Loop then CS := Scope (CS); -- Otherwise, the reference is dubious, and we cannot be sure that -- it is safe to do the replacement. else exit; end if; end loop; return False; end if; end OK_To_Do_Constant_Replacement; ------------------------------------ -- Possible_Bit_Aligned_Component -- ------------------------------------ function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is begin case Nkind (N) is -- Case of indexed component when N_Indexed_Component => declare P : constant Node_Id := Prefix (N); Ptyp : constant Entity_Id := Etype (P); begin -- If we know the component size and it is less than 64, then -- we are definitely OK. The back end always does assignment of -- misaligned small objects correctly. if Known_Static_Component_Size (Ptyp) and then Component_Size (Ptyp) <= 64 then return False; -- Otherwise, we need to test the prefix, to see if we are -- indexing from a possibly unaligned component. else return Possible_Bit_Aligned_Component (P); end if; end; -- Case of selected component when N_Selected_Component => declare P : constant Node_Id := Prefix (N); Comp : constant Entity_Id := Entity (Selector_Name (N)); begin -- If there is no component clause, then we are in the clear -- since the back end will never misalign a large component -- unless it is forced to do so. In the clear means we need -- only the recursive test on the prefix. if Component_May_Be_Bit_Aligned (Comp) then return True; else return Possible_Bit_Aligned_Component (P); end if; end; -- For a slice, test the prefix, if that is possibly misaligned, -- then for sure the slice is! when N_Slice => return Possible_Bit_Aligned_Component (Prefix (N)); -- For an unchecked conversion, check whether the expression may -- be bit-aligned. when N_Unchecked_Type_Conversion => return Possible_Bit_Aligned_Component (Expression (N)); -- If we have none of the above, it means that we have fallen off the -- top testing prefixes recursively, and we now have a stand alone -- object, where we don't have a problem. when others => return False; end case; end Possible_Bit_Aligned_Component; ----------------------------------------------- -- Process_Statements_For_Controlled_Objects -- ----------------------------------------------- procedure Process_Statements_For_Controlled_Objects (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); function Are_Wrapped (L : List_Id) return Boolean; -- Determine whether list L contains only one statement which is a block function Wrap_Statements_In_Block (L : List_Id) return Node_Id; -- Given a list of statements L, wrap it in a block statement and return -- the generated node. ----------------- -- Are_Wrapped -- ----------------- function Are_Wrapped (L : List_Id) return Boolean is Stmt : constant Node_Id := First (L); begin return Present (Stmt) and then No (Next (Stmt)) and then Nkind (Stmt) = N_Block_Statement; end Are_Wrapped; ------------------------------ -- Wrap_Statements_In_Block -- ------------------------------ function Wrap_Statements_In_Block (L : List_Id) return Node_Id is begin return Make_Block_Statement (Loc, Declarations => No_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => L)); end Wrap_Statements_In_Block; -- Local variables Block : Node_Id; -- Start of processing for Process_Statements_For_Controlled_Objects begin -- Whenever a non-handled statement list is wrapped in a block, the -- block must be explicitly analyzed to redecorate all entities in the -- list and ensure that a finalizer is properly built. case Nkind (N) is when N_Elsif_Part | N_If_Statement | N_Conditional_Entry_Call | N_Selective_Accept => -- Check the "then statements" for elsif parts and if statements if Nkind_In (N, N_Elsif_Part, N_If_Statement) and then not Is_Empty_List (Then_Statements (N)) and then not Are_Wrapped (Then_Statements (N)) and then Requires_Cleanup_Actions (Then_Statements (N), False, False) then Block := Wrap_Statements_In_Block (Then_Statements (N)); Set_Then_Statements (N, New_List (Block)); Analyze (Block); end if; -- Check the "else statements" for conditional entry calls, if -- statements and selective accepts. if Nkind_In (N, N_Conditional_Entry_Call, N_If_Statement, N_Selective_Accept) and then not Is_Empty_List (Else_Statements (N)) and then not Are_Wrapped (Else_Statements (N)) and then Requires_Cleanup_Actions (Else_Statements (N), False, False) then Block := Wrap_Statements_In_Block (Else_Statements (N)); Set_Else_Statements (N, New_List (Block)); Analyze (Block); end if; when N_Abortable_Part | N_Accept_Alternative | N_Case_Statement_Alternative | N_Delay_Alternative | N_Entry_Call_Alternative | N_Exception_Handler | N_Loop_Statement | N_Triggering_Alternative => if not Is_Empty_List (Statements (N)) and then not Are_Wrapped (Statements (N)) and then Requires_Cleanup_Actions (Statements (N), False, False) then Block := Wrap_Statements_In_Block (Statements (N)); Set_Statements (N, New_List (Block)); Analyze (Block); end if; when others => null; end case; end Process_Statements_For_Controlled_Objects; ------------------------- -- Remove_Side_Effects -- ------------------------- procedure Remove_Side_Effects (Exp : Node_Id; Name_Req : Boolean := False; Variable_Ref : Boolean := False) is Loc : constant Source_Ptr := Sloc (Exp); Exp_Type : constant Entity_Id := Etype (Exp); Svg_Suppress : constant Suppress_Array := Scope_Suppress; Def_Id : Entity_Id; E : Node_Id; New_Exp : Node_Id; Ptr_Typ_Decl : Node_Id; Ref_Type : Entity_Id; Res : Node_Id; function Side_Effect_Free (N : Node_Id) return Boolean; -- Determines if the tree N represents an expression that is known not -- to have side effects, and for which no processing is required. function Side_Effect_Free (L : List_Id) return Boolean; -- Determines if all elements of the list L are side effect free function Safe_Prefixed_Reference (N : Node_Id) return Boolean; -- The argument N is a construct where the Prefix is dereferenced if it -- is an access type and the result is a variable. The call returns True -- if the construct is side effect free (not considering side effects in -- other than the prefix which are to be tested by the caller). function Within_In_Parameter (N : Node_Id) return Boolean; -- Determines if N is a subcomponent of a composite in-parameter. If so, -- N is not side-effect free when the actual is global and modifiable -- indirectly from within a subprogram, because it may be passed by -- reference. The front-end must be conservative here and assume that -- this may happen with any array or record type. On the other hand, we -- cannot create temporaries for all expressions for which this -- condition is true, for various reasons that might require clearing up -- ??? For example, discriminant references that appear out of place, or -- spurious type errors with class-wide expressions. As a result, we -- limit the transformation to loop bounds, which is so far the only -- case that requires it. ----------------------------- -- Safe_Prefixed_Reference -- ----------------------------- function Safe_Prefixed_Reference (N : Node_Id) return Boolean is begin -- If prefix is not side effect free, definitely not safe if not Side_Effect_Free (Prefix (N)) then return False; -- If the prefix is of an access type that is not access-to-constant, -- then this construct is a variable reference, which means it is to -- be considered to have side effects if Variable_Ref is set True. elsif Is_Access_Type (Etype (Prefix (N))) and then not Is_Access_Constant (Etype (Prefix (N))) and then Variable_Ref then -- Exception is a prefix that is the result of a previous removal -- of side-effects. return Is_Entity_Name (Prefix (N)) and then not Comes_From_Source (Prefix (N)) and then Ekind (Entity (Prefix (N))) = E_Constant and then Is_Internal_Name (Chars (Entity (Prefix (N)))); -- If the prefix is an explicit dereference then this construct is a -- variable reference, which means it is to be considered to have -- side effects if Variable_Ref is True. -- We do NOT exclude dereferences of access-to-constant types because -- we handle them as constant view of variables. elsif Nkind (Prefix (N)) = N_Explicit_Dereference and then Variable_Ref then return False; -- Note: The following test is the simplest way of solving a complex -- problem uncovered by the following test (Side effect on loop bound -- that is a subcomponent of a global variable: -- with Text_Io; use Text_Io; -- procedure Tloop is -- type X is -- record -- V : Natural := 4; -- S : String (1..5) := (others => 'a'); -- end record; -- X1 : X; -- procedure Modi; -- generic -- with procedure Action; -- procedure Loop_G (Arg : X; Msg : String) -- procedure Loop_G (Arg : X; Msg : String) is -- begin -- Put_Line ("begin loop_g " & Msg & " will loop till: " -- & Natural'Image (Arg.V)); -- for Index in 1 .. Arg.V loop -- Text_Io.Put_Line -- (Natural'Image (Index) & " " & Arg.S (Index)); -- if Index > 2 then -- Modi; -- end if; -- end loop; -- Put_Line ("end loop_g " & Msg); -- end; -- procedure Loop1 is new Loop_G (Modi); -- procedure Modi is -- begin -- X1.V := 1; -- Loop1 (X1, "from modi"); -- end; -- -- begin -- Loop1 (X1, "initial"); -- end; -- The output of the above program should be: -- begin loop_g initial will loop till: 4 -- 1 a -- 2 a -- 3 a -- begin loop_g from modi will loop till: 1 -- 1 a -- end loop_g from modi -- 4 a -- begin loop_g from modi will loop till: 1 -- 1 a -- end loop_g from modi -- end loop_g initial -- If a loop bound is a subcomponent of a global variable, a -- modification of that variable within the loop may incorrectly -- affect the execution of the loop. elsif Nkind (Parent (Parent (N))) = N_Loop_Parameter_Specification and then Within_In_Parameter (Prefix (N)) and then Variable_Ref then return False; -- All other cases are side effect free else return True; end if; end Safe_Prefixed_Reference; ---------------------- -- Side_Effect_Free -- ---------------------- function Side_Effect_Free (N : Node_Id) return Boolean is begin -- Note on checks that could raise Constraint_Error. Strictly, if we -- take advantage of 11.6, these checks do not count as side effects. -- However, we would prefer to consider that they are side effects, -- since the backend CSE does not work very well on expressions which -- can raise Constraint_Error. On the other hand if we don't consider -- them to be side effect free, then we get some awkward expansions -- in -gnato mode, resulting in code insertions at a point where we -- do not have a clear model for performing the insertions. -- Special handling for entity names if Is_Entity_Name (N) then -- Variables are considered to be a side effect if Variable_Ref -- is set or if we have a volatile reference and Name_Req is off. -- If Name_Req is True then we can't help returning a name which -- effectively allows multiple references in any case. if Is_Variable (N, Use_Original_Node => False) then return not Variable_Ref and then (not Is_Volatile_Reference (N) or else Name_Req); -- Any other entity (e.g. a subtype name) is definitely side -- effect free. else return True; end if; -- A value known at compile time is always side effect free elsif Compile_Time_Known_Value (N) then return True; -- A variable renaming is not side-effect free, because the renaming -- will function like a macro in the front-end in some cases, and an -- assignment can modify the component designated by N, so we need to -- create a temporary for it. -- The guard testing for Entity being present is needed at least in -- the case of rewritten predicate expressions, and may well also be -- appropriate elsewhere. Obviously we can't go testing the entity -- field if it does not exist, so it's reasonable to say that this is -- not the renaming case if it does not exist. elsif Is_Entity_Name (Original_Node (N)) and then Present (Entity (Original_Node (N))) and then Is_Renaming_Of_Object (Entity (Original_Node (N))) and then Ekind (Entity (Original_Node (N))) /= E_Constant then return False; -- Remove_Side_Effects generates an object renaming declaration to -- capture the expression of a class-wide expression. In VM targets -- the frontend performs no expansion for dispatching calls to -- class- wide types since they are handled by the VM. Hence, we must -- locate here if this node corresponds to a previous invocation of -- Remove_Side_Effects to avoid a never ending loop in the frontend. elsif VM_Target /= No_VM and then not Comes_From_Source (N) and then Nkind (Parent (N)) = N_Object_Renaming_Declaration and then Is_Class_Wide_Type (Etype (N)) then return True; end if; -- For other than entity names and compile time known values, -- check the node kind for special processing. case Nkind (N) is -- An attribute reference is side effect free if its expressions -- are side effect free and its prefix is side effect free or -- is an entity reference. -- Is this right? what about x'first where x is a variable??? when N_Attribute_Reference => return Side_Effect_Free (Expressions (N)) and then Attribute_Name (N) /= Name_Input and then (Is_Entity_Name (Prefix (N)) or else Side_Effect_Free (Prefix (N))); -- A binary operator is side effect free if and both operands are -- side effect free. For this purpose binary operators include -- membership tests and short circuit forms. when N_Binary_Op | N_Membership_Test | N_Short_Circuit => return Side_Effect_Free (Left_Opnd (N)) and then Side_Effect_Free (Right_Opnd (N)); -- An explicit dereference is side effect free only if it is -- a side effect free prefixed reference. when N_Explicit_Dereference => return Safe_Prefixed_Reference (N); -- A call to _rep_to_pos is side effect free, since we generate -- this pure function call ourselves. Moreover it is critically -- important to make this exception, since otherwise we can have -- discriminants in array components which don't look side effect -- free in the case of an array whose index type is an enumeration -- type with an enumeration rep clause. -- All other function calls are not side effect free when N_Function_Call => return Nkind (Name (N)) = N_Identifier and then Is_TSS (Name (N), TSS_Rep_To_Pos) and then Side_Effect_Free (First (Parameter_Associations (N))); -- An indexed component is side effect free if it is a side -- effect free prefixed reference and all the indexing -- expressions are side effect free. when N_Indexed_Component => return Side_Effect_Free (Expressions (N)) and then Safe_Prefixed_Reference (N); -- A type qualification is side effect free if the expression -- is side effect free. when N_Qualified_Expression => return Side_Effect_Free (Expression (N)); -- A selected component is side effect free only if it is a side -- effect free prefixed reference. If it designates a component -- with a rep. clause it must be treated has having a potential -- side effect, because it may be modified through a renaming, and -- a subsequent use of the renaming as a macro will yield the -- wrong value. This complex interaction between renaming and -- removing side effects is a reminder that the latter has become -- a headache to maintain, and that it should be removed in favor -- of the gcc mechanism to capture values ??? when N_Selected_Component => if Nkind (Parent (N)) = N_Explicit_Dereference and then Has_Non_Standard_Rep (Designated_Type (Etype (N))) then return False; else return Safe_Prefixed_Reference (N); end if; -- A range is side effect free if the bounds are side effect free when N_Range => return Side_Effect_Free (Low_Bound (N)) and then Side_Effect_Free (High_Bound (N)); -- A slice is side effect free if it is a side effect free -- prefixed reference and the bounds are side effect free. when N_Slice => return Side_Effect_Free (Discrete_Range (N)) and then Safe_Prefixed_Reference (N); -- A type conversion is side effect free if the expression to be -- converted is side effect free. when N_Type_Conversion => return Side_Effect_Free (Expression (N)); -- A unary operator is side effect free if the operand -- is side effect free. when N_Unary_Op => return Side_Effect_Free (Right_Opnd (N)); -- An unchecked type conversion is side effect free only if it -- is safe and its argument is side effect free. when N_Unchecked_Type_Conversion => return Safe_Unchecked_Type_Conversion (N) and then Side_Effect_Free (Expression (N)); -- An unchecked expression is side effect free if its expression -- is side effect free. when N_Unchecked_Expression => return Side_Effect_Free (Expression (N)); -- A literal is side effect free when N_Character_Literal | N_Integer_Literal | N_Real_Literal | N_String_Literal => return True; -- We consider that anything else has side effects. This is a bit -- crude, but we are pretty close for most common cases, and we -- are certainly correct (i.e. we never return True when the -- answer should be False). when others => return False; end case; end Side_Effect_Free; -- A list is side effect free if all elements of the list are side -- effect free. function Side_Effect_Free (L : List_Id) return Boolean is N : Node_Id; begin if L = No_List or else L = Error_List then return True; else N := First (L); while Present (N) loop if not Side_Effect_Free (N) then return False; else Next (N); end if; end loop; return True; end if; end Side_Effect_Free; ------------------------- -- Within_In_Parameter -- ------------------------- function Within_In_Parameter (N : Node_Id) return Boolean is begin if not Comes_From_Source (N) then return False; elsif Is_Entity_Name (N) then return Ekind (Entity (N)) = E_In_Parameter; elsif Nkind (N) = N_Indexed_Component or else Nkind (N) = N_Selected_Component then return Within_In_Parameter (Prefix (N)); else return False; end if; end Within_In_Parameter; -- Start of processing for Remove_Side_Effects begin -- Handle cases in which there is nothing to do if not Expander_Active then return; end if; -- Cannot generate temporaries if the invocation to remove side effects -- was issued too early and the type of the expression is not resolved -- (this happens because routines Duplicate_Subexpr_XX implicitly invoke -- Remove_Side_Effects). if No (Exp_Type) or else Ekind (Exp_Type) = E_Access_Attribute_Type then return; -- No action needed for side-effect free expressions elsif Side_Effect_Free (Exp) then return; end if; -- All this must not have any checks Scope_Suppress := (others => True); -- If it is a scalar type and we need to capture the value, just make -- a copy. Likewise for a function call, an attribute reference, an -- allocator, or an operator. And if we have a volatile reference and -- Name_Req is not set (see comments above for Side_Effect_Free). if Is_Elementary_Type (Exp_Type) and then (Variable_Ref or else Nkind (Exp) = N_Function_Call or else Nkind (Exp) = N_Attribute_Reference or else Nkind (Exp) = N_Allocator or else Nkind (Exp) in N_Op or else (not Name_Req and then Is_Volatile_Reference (Exp))) then Def_Id := Make_Temporary (Loc, 'R', Exp); Set_Etype (Def_Id, Exp_Type); Res := New_Reference_To (Def_Id, Loc); -- If the expression is a packed reference, it must be reanalyzed and -- expanded, depending on context. This is the case for actuals where -- a constraint check may capture the actual before expansion of the -- call is complete. if Nkind (Exp) = N_Indexed_Component and then Is_Packed (Etype (Prefix (Exp))) then Set_Analyzed (Exp, False); Set_Analyzed (Prefix (Exp), False); end if; E := Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Reference_To (Exp_Type, Loc), Constant_Present => True, Expression => Relocate_Node (Exp)); Set_Assignment_OK (E); Insert_Action (Exp, E); -- If the expression has the form v.all then we can just capture the -- pointer, and then do an explicit dereference on the result. elsif Nkind (Exp) = N_Explicit_Dereference then Def_Id := Make_Temporary (Loc, 'R', Exp); Res := Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc)); Insert_Action (Exp, Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Reference_To (Etype (Prefix (Exp)), Loc), Constant_Present => True, Expression => Relocate_Node (Prefix (Exp)))); -- Similar processing for an unchecked conversion of an expression of -- the form v.all, where we want the same kind of treatment. elsif Nkind (Exp) = N_Unchecked_Type_Conversion and then Nkind (Expression (Exp)) = N_Explicit_Dereference then Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref); Scope_Suppress := Svg_Suppress; return; -- If this is a type conversion, leave the type conversion and remove -- the side effects in the expression. This is important in several -- circumstances: for change of representations, and also when this is a -- view conversion to a smaller object, where gigi can end up creating -- its own temporary of the wrong size. elsif Nkind (Exp) = N_Type_Conversion then Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref); Scope_Suppress := Svg_Suppress; return; -- If this is an unchecked conversion that Gigi can't handle, make -- a copy or a use a renaming to capture the value. elsif Nkind (Exp) = N_Unchecked_Type_Conversion and then not Safe_Unchecked_Type_Conversion (Exp) then if CW_Or_Has_Controlled_Part (Exp_Type) then -- Use a renaming to capture the expression, rather than create -- a controlled temporary. Def_Id := Make_Temporary (Loc, 'R', Exp); Res := New_Reference_To (Def_Id, Loc); Insert_Action (Exp, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Mark => New_Reference_To (Exp_Type, Loc), Name => Relocate_Node (Exp))); else Def_Id := Make_Temporary (Loc, 'R', Exp); Set_Etype (Def_Id, Exp_Type); Res := New_Reference_To (Def_Id, Loc); E := Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Reference_To (Exp_Type, Loc), Constant_Present => not Is_Variable (Exp), Expression => Relocate_Node (Exp)); Set_Assignment_OK (E); Insert_Action (Exp, E); end if; -- For expressions that denote objects, we can use a renaming scheme. -- This is needed for correctness in the case of a volatile object of a -- non-volatile type because the Make_Reference call of the "default" -- approach would generate an illegal access value (an access value -- cannot designate such an object - see Analyze_Reference). We skip -- using this scheme if we have an object of a volatile type and we do -- not have Name_Req set true (see comments above for Side_Effect_Free). elsif Is_Object_Reference (Exp) and then Nkind (Exp) /= N_Function_Call and then (Name_Req or else not Treat_As_Volatile (Exp_Type)) then Def_Id := Make_Temporary (Loc, 'R', Exp); if Nkind (Exp) = N_Selected_Component and then Nkind (Prefix (Exp)) = N_Function_Call and then Is_Array_Type (Exp_Type) then -- Avoid generating a variable-sized temporary, by generating -- the renaming declaration just for the function call. The -- transformation could be refined to apply only when the array -- component is constrained by a discriminant??? Res := Make_Selected_Component (Loc, Prefix => New_Occurrence_Of (Def_Id, Loc), Selector_Name => Selector_Name (Exp)); Insert_Action (Exp, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Mark => New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc), Name => Relocate_Node (Prefix (Exp)))); else Res := New_Reference_To (Def_Id, Loc); Insert_Action (Exp, Make_Object_Renaming_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Mark => New_Reference_To (Exp_Type, Loc), Name => Relocate_Node (Exp))); end if; -- If this is a packed reference, or a selected component with -- a non-standard representation, a reference to the temporary -- will be replaced by a copy of the original expression (see -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be -- elaborated by gigi, and is of course not to be replaced in-line -- by the expression it renames, which would defeat the purpose of -- removing the side-effect. if (Nkind (Exp) = N_Selected_Component or else Nkind (Exp) = N_Indexed_Component) and then Has_Non_Standard_Rep (Etype (Prefix (Exp))) then null; else Set_Is_Renaming_Of_Object (Def_Id, False); end if; -- Otherwise we generate a reference to the value else -- An expression which is in Alfa mode is considered side effect free -- if the resulting value is captured by a variable or a constant. if Alfa_Mode and then Nkind (Parent (Exp)) = N_Object_Declaration then return; end if; -- Special processing for function calls that return a limited type. -- We need to build a declaration that will enable build-in-place -- expansion of the call. This is not done if the context is already -- an object declaration, to prevent infinite recursion. -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have -- to accommodate functions returning limited objects by reference. if Ada_Version >= Ada_2005 and then Nkind (Exp) = N_Function_Call and then Is_Immutably_Limited_Type (Etype (Exp)) and then Nkind (Parent (Exp)) /= N_Object_Declaration then declare Obj : constant Entity_Id := Make_Temporary (Loc, 'F', Exp); Decl : Node_Id; begin Decl := Make_Object_Declaration (Loc, Defining_Identifier => Obj, Object_Definition => New_Occurrence_Of (Exp_Type, Loc), Expression => Relocate_Node (Exp)); Insert_Action (Exp, Decl); Set_Etype (Obj, Exp_Type); Rewrite (Exp, New_Occurrence_Of (Obj, Loc)); return; end; end if; Def_Id := Make_Temporary (Loc, 'R', Exp); Set_Etype (Def_Id, Exp_Type); -- The regular expansion of functions with side effects involves the -- generation of an access type to capture the return value found on -- the secondary stack. Since Alfa (and why) cannot process access -- types, use a different approach which ignores the secondary stack -- and "copies" the returned object. if Alfa_Mode then Res := New_Reference_To (Def_Id, Loc); Ref_Type := Exp_Type; -- Regular expansion utilizing an access type and 'reference else Res := Make_Explicit_Dereference (Loc, Prefix => New_Reference_To (Def_Id, Loc)); -- Generate: -- type Ann is access all <Exp_Type>; Ref_Type := Make_Temporary (Loc, 'A'); Ptr_Typ_Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Ref_Type, Type_Definition => Make_Access_To_Object_Definition (Loc, All_Present => True, Subtype_Indication => New_Reference_To (Exp_Type, Loc))); Insert_Action (Exp, Ptr_Typ_Decl); end if; E := Exp; if Nkind (E) = N_Explicit_Dereference then New_Exp := Relocate_Node (Prefix (E)); else E := Relocate_Node (E); -- Do not generate a 'reference in Alfa mode since the access type -- is not created in the first place. if Alfa_Mode then New_Exp := E; -- Otherwise generate reference, marking the value as non-null -- since we know it cannot be null and we don't want a check. else New_Exp := Make_Reference (Loc, E); Set_Is_Known_Non_Null (Def_Id); end if; end if; if Is_Delayed_Aggregate (E) then -- The expansion of nested aggregates is delayed until the -- enclosing aggregate is expanded. As aggregates are often -- qualified, the predicate applies to qualified expressions as -- well, indicating that the enclosing aggregate has not been -- expanded yet. At this point the aggregate is part of a -- stand-alone declaration, and must be fully expanded. if Nkind (E) = N_Qualified_Expression then Set_Expansion_Delayed (Expression (E), False); Set_Analyzed (Expression (E), False); else Set_Expansion_Delayed (E, False); end if; Set_Analyzed (E, False); end if; Insert_Action (Exp, Make_Object_Declaration (Loc, Defining_Identifier => Def_Id, Object_Definition => New_Reference_To (Ref_Type, Loc), Constant_Present => True, Expression => New_Exp)); end if; -- Preserve the Assignment_OK flag in all copies, since at least one -- copy may be used in a context where this flag must be set (otherwise -- why would the flag be set in the first place). Set_Assignment_OK (Res, Assignment_OK (Exp)); -- Finally rewrite the original expression and we are done Rewrite (Exp, Res); Analyze_And_Resolve (Exp, Exp_Type); Scope_Suppress := Svg_Suppress; end Remove_Side_Effects; --------------------------- -- Represented_As_Scalar -- --------------------------- function Represented_As_Scalar (T : Entity_Id) return Boolean is UT : constant Entity_Id := Underlying_Type (T); begin return Is_Scalar_Type (UT) or else (Is_Bit_Packed_Array (UT) and then Is_Scalar_Type (Packed_Array_Type (UT))); end Represented_As_Scalar; ------------------------------ -- Requires_Cleanup_Actions -- ------------------------------ function Requires_Cleanup_Actions (N : Node_Id) return Boolean is For_Pkg : constant Boolean := Nkind_In (N, N_Package_Body, N_Package_Specification); begin case Nkind (N) is when N_Accept_Statement | N_Block_Statement | N_Entry_Body | N_Package_Body | N_Protected_Body | N_Subprogram_Body | N_Task_Body => return Requires_Cleanup_Actions (Declarations (N), For_Pkg, True) or else (Present (Handled_Statement_Sequence (N)) and then Requires_Cleanup_Actions (Statements (Handled_Statement_Sequence (N)), For_Pkg, True)); when N_Package_Specification => return Requires_Cleanup_Actions (Visible_Declarations (N), For_Pkg, True) or else Requires_Cleanup_Actions (Private_Declarations (N), For_Pkg, True); when others => return False; end case; end Requires_Cleanup_Actions; ------------------------------ -- Requires_Cleanup_Actions -- ------------------------------ function Requires_Cleanup_Actions (L : List_Id; For_Package : Boolean; Nested_Constructs : Boolean) return Boolean is Decl : Node_Id; Expr : Node_Id; Obj_Id : Entity_Id; Obj_Typ : Entity_Id; Pack_Id : Entity_Id; Typ : Entity_Id; begin if No (L) or else Is_Empty_List (L) then return False; end if; Decl := First (L); while Present (Decl) loop -- Library-level tagged types if Nkind (Decl) = N_Full_Type_Declaration then Typ := Defining_Identifier (Decl); if Is_Tagged_Type (Typ) and then Is_Library_Level_Entity (Typ) and then Convention (Typ) = Convention_Ada and then Present (Access_Disp_Table (Typ)) and then RTE_Available (RE_Unregister_Tag) and then not No_Run_Time_Mode and then not Is_Abstract_Type (Typ) then return True; end if; -- Regular object declarations elsif Nkind (Decl) = N_Object_Declaration then Obj_Id := Defining_Identifier (Decl); Obj_Typ := Base_Type (Etype (Obj_Id)); Expr := Expression (Decl); -- Bypass any form of processing for objects which have their -- finalization disabled. This applies only to objects at the -- library level. if For_Package and then Finalize_Storage_Only (Obj_Typ) then null; -- Transient variables are treated separately in order to minimize -- the size of the generated code. See Exp_Ch7.Process_Transient_ -- Objects. elsif Is_Processed_Transient (Obj_Id) then null; -- The object is of the form: -- Obj : Typ [:= Expr]; -- -- Do not process the incomplete view of a deferred constant. Do -- not consider tag-to-class-wide conversions. elsif not Is_Imported (Obj_Id) and then Needs_Finalization (Obj_Typ) and then not (Ekind (Obj_Id) = E_Constant and then not Has_Completion (Obj_Id)) and then not Is_Tag_To_Class_Wide_Conversion (Obj_Id) then return True; -- The object is of the form: -- Obj : Access_Typ := Non_BIP_Function_Call'reference; -- -- Obj : Access_Typ := -- BIP_Function_Call -- (..., BIPaccess => null, ...)'reference; elsif Is_Access_Type (Obj_Typ) and then Needs_Finalization (Available_View (Designated_Type (Obj_Typ))) and then Present (Expr) and then (Is_Null_Access_BIP_Func_Call (Expr) or else (Is_Non_BIP_Func_Call (Expr) and then not Is_Related_To_Func_Return (Obj_Id))) then return True; -- Processing for "hook" objects generated for controlled -- transients declared inside an Expression_With_Actions. elsif Is_Access_Type (Obj_Typ) and then Present (Return_Flag_Or_Transient_Decl (Obj_Id)) and then Nkind (Return_Flag_Or_Transient_Decl (Obj_Id)) = N_Object_Declaration and then Is_Finalizable_Transient (Return_Flag_Or_Transient_Decl (Obj_Id), Decl) then return True; -- Simple protected objects which use type System.Tasking. -- Protected_Objects.Protection to manage their locks should be -- treated as controlled since they require manual cleanup. elsif Ekind (Obj_Id) = E_Variable and then (Is_Simple_Protected_Type (Obj_Typ) or else Has_Simple_Protected_Object (Obj_Typ)) then return True; end if; -- Specific cases of object renamings elsif Nkind (Decl) = N_Object_Renaming_Declaration then Obj_Id := Defining_Identifier (Decl); Obj_Typ := Base_Type (Etype (Obj_Id)); -- Bypass any form of processing for objects which have their -- finalization disabled. This applies only to objects at the -- library level. if For_Package and then Finalize_Storage_Only (Obj_Typ) then null; -- Return object of a build-in-place function. This case is -- recognized and marked by the expansion of an extended return -- statement (see Expand_N_Extended_Return_Statement). elsif Needs_Finalization (Obj_Typ) and then Is_Return_Object (Obj_Id) and then Present (Return_Flag_Or_Transient_Decl (Obj_Id)) then return True; -- Detect a case where a source object has been initialized by a -- controlled function call which was later rewritten as a class- -- wide conversion of Ada.Tags.Displace. -- Obj : Class_Wide_Type := Function_Call (...); -- Temp : ... := Function_Call (...)'reference; -- Obj : Class_Wide_Type renames -- (... Ada.Tags.Displace (Temp)); elsif Is_Displacement_Of_Ctrl_Function_Result (Obj_Id) then return True; end if; -- Inspect the freeze node of an access-to-controlled type and look -- for a delayed finalization master. This case arises when the -- freeze actions are inserted at a later time than the expansion of -- the context. Since Build_Finalizer is never called on a single -- construct twice, the master will be ultimately left out and never -- finalized. This is also needed for freeze actions of designated -- types themselves, since in some cases the finalization master is -- associated with a designated type's freeze node rather than that -- of the access type (see handling for freeze actions in -- Build_Finalization_Master). elsif Nkind (Decl) = N_Freeze_Entity and then Present (Actions (Decl)) then Typ := Entity (Decl); if ((Is_Access_Type (Typ) and then not Is_Access_Subprogram_Type (Typ) and then Needs_Finalization (Available_View (Designated_Type (Typ)))) or else (Is_Type (Typ) and then Needs_Finalization (Typ))) and then Requires_Cleanup_Actions (Actions (Decl), For_Package, Nested_Constructs) then return True; end if; -- Nested package declarations elsif Nested_Constructs and then Nkind (Decl) = N_Package_Declaration then Pack_Id := Defining_Unit_Name (Specification (Decl)); if Nkind (Pack_Id) = N_Defining_Program_Unit_Name then Pack_Id := Defining_Identifier (Pack_Id); end if; if Ekind (Pack_Id) /= E_Generic_Package and then Requires_Cleanup_Actions (Specification (Decl)) then return True; end if; -- Nested package bodies elsif Nested_Constructs and then Nkind (Decl) = N_Package_Body then Pack_Id := Corresponding_Spec (Decl); if Ekind (Pack_Id) /= E_Generic_Package and then Requires_Cleanup_Actions (Decl) then return True; end if; end if; Next (Decl); end loop; return False; end Requires_Cleanup_Actions; ------------------------------------ -- Safe_Unchecked_Type_Conversion -- ------------------------------------ -- Note: this function knows quite a bit about the exact requirements of -- Gigi with respect to unchecked type conversions, and its code must be -- coordinated with any changes in Gigi in this area. -- The above requirements should be documented in Sinfo ??? function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is Otyp : Entity_Id; Ityp : Entity_Id; Oalign : Uint; Ialign : Uint; Pexp : constant Node_Id := Parent (Exp); begin -- If the expression is the RHS of an assignment or object declaration -- we are always OK because there will always be a target. -- Object renaming declarations, (generated for view conversions of -- actuals in inlined calls), like object declarations, provide an -- explicit type, and are safe as well. if (Nkind (Pexp) = N_Assignment_Statement and then Expression (Pexp) = Exp) or else Nkind (Pexp) = N_Object_Declaration or else Nkind (Pexp) = N_Object_Renaming_Declaration then return True; -- If the expression is the prefix of an N_Selected_Component we should -- also be OK because GCC knows to look inside the conversion except if -- the type is discriminated. We assume that we are OK anyway if the -- type is not set yet or if it is controlled since we can't afford to -- introduce a temporary in this case. elsif Nkind (Pexp) = N_Selected_Component and then Prefix (Pexp) = Exp then if No (Etype (Pexp)) then return True; else return not Has_Discriminants (Etype (Pexp)) or else Is_Constrained (Etype (Pexp)); end if; end if; -- Set the output type, this comes from Etype if it is set, otherwise we -- take it from the subtype mark, which we assume was already fully -- analyzed. if Present (Etype (Exp)) then Otyp := Etype (Exp); else Otyp := Entity (Subtype_Mark (Exp)); end if; -- The input type always comes from the expression, and we assume -- this is indeed always analyzed, so we can simply get the Etype. Ityp := Etype (Expression (Exp)); -- Initialize alignments to unknown so far Oalign := No_Uint; Ialign := No_Uint; -- Replace a concurrent type by its corresponding record type and each -- type by its underlying type and do the tests on those. The original -- type may be a private type whose completion is a concurrent type, so -- find the underlying type first. if Present (Underlying_Type (Otyp)) then Otyp := Underlying_Type (Otyp); end if; if Present (Underlying_Type (Ityp)) then Ityp := Underlying_Type (Ityp); end if; if Is_Concurrent_Type (Otyp) then Otyp := Corresponding_Record_Type (Otyp); end if; if Is_Concurrent_Type (Ityp) then Ityp := Corresponding_Record_Type (Ityp); end if; -- If the base types are the same, we know there is no problem since -- this conversion will be a noop. if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then return True; -- Same if this is an upwards conversion of an untagged type, and there -- are no constraints involved (could be more general???) elsif Etype (Ityp) = Otyp and then not Is_Tagged_Type (Ityp) and then not Has_Discriminants (Ityp) and then No (First_Rep_Item (Base_Type (Ityp))) then return True; -- If the expression has an access type (object or subprogram) we assume -- that the conversion is safe, because the size of the target is safe, -- even if it is a record (which might be treated as having unknown size -- at this point). elsif Is_Access_Type (Ityp) then return True; -- If the size of output type is known at compile time, there is never -- a problem. Note that unconstrained records are considered to be of -- known size, but we can't consider them that way here, because we are -- talking about the actual size of the object. -- We also make sure that in addition to the size being known, we do not -- have a case which might generate an embarrassingly large temp in -- stack checking mode. elsif Size_Known_At_Compile_Time (Otyp) and then (not Stack_Checking_Enabled or else not May_Generate_Large_Temp (Otyp)) and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp)) then return True; -- If either type is tagged, then we know the alignment is OK so -- Gigi will be able to use pointer punning. elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then return True; -- If either type is a limited record type, we cannot do a copy, so say -- safe since there's nothing else we can do. elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then return True; -- Conversions to and from packed array types are always ignored and -- hence are safe. elsif Is_Packed_Array_Type (Otyp) or else Is_Packed_Array_Type (Ityp) then return True; end if; -- The only other cases known to be safe is if the input type's -- alignment is known to be at least the maximum alignment for the -- target or if both alignments are known and the output type's -- alignment is no stricter than the input's. We can use the component -- type alignement for an array if a type is an unpacked array type. if Present (Alignment_Clause (Otyp)) then Oalign := Expr_Value (Expression (Alignment_Clause (Otyp))); elsif Is_Array_Type (Otyp) and then Present (Alignment_Clause (Component_Type (Otyp))) then Oalign := Expr_Value (Expression (Alignment_Clause (Component_Type (Otyp)))); end if; if Present (Alignment_Clause (Ityp)) then Ialign := Expr_Value (Expression (Alignment_Clause (Ityp))); elsif Is_Array_Type (Ityp) and then Present (Alignment_Clause (Component_Type (Ityp))) then Ialign := Expr_Value (Expression (Alignment_Clause (Component_Type (Ityp)))); end if; if Ialign /= No_Uint and then Ialign > Maximum_Alignment then return True; elsif Ialign /= No_Uint and then Oalign /= No_Uint and then Ialign <= Oalign then return True; -- Otherwise, Gigi cannot handle this and we must make a temporary else return False; end if; end Safe_Unchecked_Type_Conversion; --------------------------------- -- Set_Current_Value_Condition -- --------------------------------- -- Note: the implementation of this procedure is very closely tied to the -- implementation of Get_Current_Value_Condition. Here we set required -- Current_Value fields, and in Get_Current_Value_Condition, we interpret -- them, so they must have a consistent view. procedure Set_Current_Value_Condition (Cnode : Node_Id) is procedure Set_Entity_Current_Value (N : Node_Id); -- If N is an entity reference, where the entity is of an appropriate -- kind, then set the current value of this entity to Cnode, unless -- there is already a definite value set there. procedure Set_Expression_Current_Value (N : Node_Id); -- If N is of an appropriate form, sets an appropriate entry in current -- value fields of relevant entities. Multiple entities can be affected -- in the case of an AND or AND THEN. ------------------------------ -- Set_Entity_Current_Value -- ------------------------------ procedure Set_Entity_Current_Value (N : Node_Id) is begin if Is_Entity_Name (N) then declare Ent : constant Entity_Id := Entity (N); begin -- Don't capture if not safe to do so if not Safe_To_Capture_Value (N, Ent, Cond => True) then return; end if; -- Here we have a case where the Current_Value field may need -- to be set. We set it if it is not already set to a compile -- time expression value. -- Note that this represents a decision that one condition -- blots out another previous one. That's certainly right if -- they occur at the same level. If the second one is nested, -- then the decision is neither right nor wrong (it would be -- equally OK to leave the outer one in place, or take the new -- inner one. Really we should record both, but our data -- structures are not that elaborate. if Nkind (Current_Value (Ent)) not in N_Subexpr then Set_Current_Value (Ent, Cnode); end if; end; end if; end Set_Entity_Current_Value; ---------------------------------- -- Set_Expression_Current_Value -- ---------------------------------- procedure Set_Expression_Current_Value (N : Node_Id) is Cond : Node_Id; begin Cond := N; -- Loop to deal with (ignore for now) any NOT operators present. The -- presence of NOT operators will be handled properly when we call -- Get_Current_Value_Condition. while Nkind (Cond) = N_Op_Not loop Cond := Right_Opnd (Cond); end loop; -- For an AND or AND THEN, recursively process operands if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then Set_Expression_Current_Value (Left_Opnd (Cond)); Set_Expression_Current_Value (Right_Opnd (Cond)); return; end if; -- Check possible relational operator if Nkind (Cond) in N_Op_Compare then if Compile_Time_Known_Value (Right_Opnd (Cond)) then Set_Entity_Current_Value (Left_Opnd (Cond)); elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then Set_Entity_Current_Value (Right_Opnd (Cond)); end if; -- Check possible boolean variable reference else Set_Entity_Current_Value (Cond); end if; end Set_Expression_Current_Value; -- Start of processing for Set_Current_Value_Condition begin Set_Expression_Current_Value (Condition (Cnode)); end Set_Current_Value_Condition; -------------------------- -- Set_Elaboration_Flag -- -------------------------- procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); Ent : constant Entity_Id := Elaboration_Entity (Spec_Id); Asn : Node_Id; begin if Present (Ent) then -- Nothing to do if at the compilation unit level, because in this -- case the flag is set by the binder generated elaboration routine. if Nkind (Parent (N)) = N_Compilation_Unit then null; -- Here we do need to generate an assignment statement else Check_Restriction (No_Elaboration_Code, N); Asn := Make_Assignment_Statement (Loc, Name => New_Occurrence_Of (Ent, Loc), Expression => Make_Integer_Literal (Loc, Uint_1)); if Nkind (Parent (N)) = N_Subunit then Insert_After (Corresponding_Stub (Parent (N)), Asn); else Insert_After (N, Asn); end if; Analyze (Asn); -- Kill current value indication. This is necessary because the -- tests of this flag are inserted out of sequence and must not -- pick up bogus indications of the wrong constant value. Set_Current_Value (Ent, Empty); end if; end if; end Set_Elaboration_Flag; ---------------------------- -- Set_Renamed_Subprogram -- ---------------------------- procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is begin -- If input node is an identifier, we can just reset it if Nkind (N) = N_Identifier then Set_Chars (N, Chars (E)); Set_Entity (N, E); -- Otherwise we have to do a rewrite, preserving Comes_From_Source else declare CS : constant Boolean := Comes_From_Source (N); begin Rewrite (N, Make_Identifier (Sloc (N), Chars (E))); Set_Entity (N, E); Set_Comes_From_Source (N, CS); Set_Analyzed (N, True); end; end if; end Set_Renamed_Subprogram; ---------------------------------- -- Silly_Boolean_Array_Not_Test -- ---------------------------------- -- This procedure implements an odd and silly test. We explicitly check -- for the case where the 'First of the component type is equal to the -- 'Last of this component type, and if this is the case, we make sure -- that constraint error is raised. The reason is that the NOT is bound -- to cause CE in this case, and we will not otherwise catch it. -- No such check is required for AND and OR, since for both these cases -- False op False = False, and True op True = True. For the XOR case, -- see Silly_Boolean_Array_Xor_Test. -- Believe it or not, this was reported as a bug. Note that nearly always, -- the test will evaluate statically to False, so the code will be -- statically removed, and no extra overhead caused. procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); CT : constant Entity_Id := Component_Type (T); begin -- The check we install is -- constraint_error when -- component_type'first = component_type'last -- and then array_type'Length /= 0) -- We need the last guard because we don't want to raise CE for empty -- arrays since no out of range values result. (Empty arrays with a -- component type of True .. True -- very useful -- even the ACATS -- does not test that marginal case!) Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Make_And_Then (Loc, Left_Opnd => Make_Op_Eq (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_First), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_Last)), Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))), Reason => CE_Range_Check_Failed)); end Silly_Boolean_Array_Not_Test; ---------------------------------- -- Silly_Boolean_Array_Xor_Test -- ---------------------------------- -- This procedure implements an odd and silly test. We explicitly check -- for the XOR case where the component type is True .. True, since this -- will raise constraint error. A special check is required since CE -- will not be generated otherwise (cf Expand_Packed_Not). -- No such check is required for AND and OR, since for both these cases -- False op False = False, and True op True = True, and no check is -- required for the case of False .. False, since False xor False = False. -- See also Silly_Boolean_Array_Not_Test procedure Silly_Boolean_Array_Xor_Test (N : Node_Id; T : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); CT : constant Entity_Id := Component_Type (T); begin -- The check we install is -- constraint_error when -- Boolean (component_type'First) -- and then Boolean (component_type'Last) -- and then array_type'Length /= 0) -- We need the last guard because we don't want to raise CE for empty -- arrays since no out of range values result (Empty arrays with a -- component type of True .. True -- very useful -- even the ACATS -- does not test that marginal case!). Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Make_And_Then (Loc, Left_Opnd => Make_And_Then (Loc, Left_Opnd => Convert_To (Standard_Boolean, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_First)), Right_Opnd => Convert_To (Standard_Boolean, Make_Attribute_Reference (Loc, Prefix => New_Occurrence_Of (CT, Loc), Attribute_Name => Name_Last))), Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))), Reason => CE_Range_Check_Failed)); end Silly_Boolean_Array_Xor_Test; -------------------------- -- Target_Has_Fixed_Ops -- -------------------------- Integer_Sized_Small : Ureal; -- Set to 2.0 ** -(Integer'Size - 1) the first time that this function is -- called (we don't want to compute it more than once!) Long_Integer_Sized_Small : Ureal; -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this function -- is called (we don't want to compute it more than once) First_Time_For_THFO : Boolean := True; -- Set to False after first call (if Fractional_Fixed_Ops_On_Target) function Target_Has_Fixed_Ops (Left_Typ : Entity_Id; Right_Typ : Entity_Id; Result_Typ : Entity_Id) return Boolean is function Is_Fractional_Type (Typ : Entity_Id) return Boolean; -- Return True if the given type is a fixed-point type with a small -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have -- an absolute value less than 1.0. This is currently limited to -- fixed-point types that map to Integer or Long_Integer. ------------------------ -- Is_Fractional_Type -- ------------------------ function Is_Fractional_Type (Typ : Entity_Id) return Boolean is begin if Esize (Typ) = Standard_Integer_Size then return Small_Value (Typ) = Integer_Sized_Small; elsif Esize (Typ) = Standard_Long_Integer_Size then return Small_Value (Typ) = Long_Integer_Sized_Small; else return False; end if; end Is_Fractional_Type; -- Start of processing for Target_Has_Fixed_Ops begin -- Return False if Fractional_Fixed_Ops_On_Target is false if not Fractional_Fixed_Ops_On_Target then return False; end if; -- Here the target has Fractional_Fixed_Ops, if first time, compute -- standard constants used by Is_Fractional_Type. if First_Time_For_THFO then First_Time_For_THFO := False; Integer_Sized_Small := UR_From_Components (Num => Uint_1, Den => UI_From_Int (Standard_Integer_Size - 1), Rbase => 2); Long_Integer_Sized_Small := UR_From_Components (Num => Uint_1, Den => UI_From_Int (Standard_Long_Integer_Size - 1), Rbase => 2); end if; -- Return True if target supports fixed-by-fixed multiply/divide for -- fractional fixed-point types (see Is_Fractional_Type) and the operand -- and result types are equivalent fractional types. return Is_Fractional_Type (Base_Type (Left_Typ)) and then Is_Fractional_Type (Base_Type (Right_Typ)) and then Is_Fractional_Type (Base_Type (Result_Typ)) and then Esize (Left_Typ) = Esize (Right_Typ) and then Esize (Left_Typ) = Esize (Result_Typ); end Target_Has_Fixed_Ops; ------------------------------------------ -- Type_May_Have_Bit_Aligned_Components -- ------------------------------------------ function Type_May_Have_Bit_Aligned_Components (Typ : Entity_Id) return Boolean is begin -- Array type, check component type if Is_Array_Type (Typ) then return Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)); -- Record type, check components elsif Is_Record_Type (Typ) then declare E : Entity_Id; begin E := First_Component_Or_Discriminant (Typ); while Present (E) loop if Component_May_Be_Bit_Aligned (E) or else Type_May_Have_Bit_Aligned_Components (Etype (E)) then return True; end if; Next_Component_Or_Discriminant (E); end loop; return False; end; -- Type other than array or record is always OK else return False; end if; end Type_May_Have_Bit_Aligned_Components; ---------------------------- -- Wrap_Cleanup_Procedure -- ---------------------------- procedure Wrap_Cleanup_Procedure (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Stseq : constant Node_Id := Handled_Statement_Sequence (N); Stmts : constant List_Id := Statements (Stseq); begin if Abort_Allowed then Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer)); Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer)); end if; end Wrap_Cleanup_Procedure; end Exp_Util;
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