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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E X P _ A G G R -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2012, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Checks; use Checks; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Expander; use Expander; with Exp_Util; use Exp_Util; with Exp_Ch3; use Exp_Ch3; with Exp_Ch6; use Exp_Ch6; with Exp_Ch7; use Exp_Ch7; with Exp_Ch9; use Exp_Ch9; with Exp_Disp; use Exp_Disp; with Exp_Tss; use Exp_Tss; with Fname; use Fname; with Freeze; use Freeze; with Itypes; use Itypes; with Lib; use Lib; with Namet; use Namet; with Nmake; use Nmake; with Nlists; use Nlists; with Opt; use Opt; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Ttypes; use Ttypes; with Sem; use Sem; with Sem_Aggr; use Sem_Aggr; with Sem_Aux; use Sem_Aux; with Sem_Ch3; use Sem_Ch3; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Util; use Sem_Util; with Sinfo; use Sinfo; with Snames; use Snames; with Stand; use Stand; with Targparm; use Targparm; with Tbuild; use Tbuild; with Uintp; use Uintp; package body Exp_Aggr is type Case_Bounds is record Choice_Lo : Node_Id; Choice_Hi : Node_Id; Choice_Node : Node_Id; end record; type Case_Table_Type is array (Nat range <>) of Case_Bounds; -- Table type used by Check_Case_Choices procedure function Has_Default_Init_Comps (N : Node_Id) return Boolean; -- N is an aggregate (record or array). Checks the presence of default -- initialization (<>) in any component (Ada 2005: AI-287). function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean; -- Returns true if N is an aggregate used to initialize the components -- of an statically allocated dispatch table. function Must_Slide (Obj_Type : Entity_Id; Typ : Entity_Id) return Boolean; -- A static array aggregate in an object declaration can in most cases be -- expanded in place. The one exception is when the aggregate is given -- with component associations that specify different bounds from those of -- the type definition in the object declaration. In this pathological -- case the aggregate must slide, and we must introduce an intermediate -- temporary to hold it. -- -- The same holds in an assignment to one-dimensional array of arrays, -- when a component may be given with bounds that differ from those of the -- component type. procedure Sort_Case_Table (Case_Table : in out Case_Table_Type); -- Sort the Case Table using the Lower Bound of each Choice as the key. -- A simple insertion sort is used since the number of choices in a case -- statement of variant part will usually be small and probably in near -- sorted order. ------------------------------------------------------ -- Local subprograms for Record Aggregate Expansion -- ------------------------------------------------------ function Build_Record_Aggr_Code (N : Node_Id; Typ : Entity_Id; Lhs : Node_Id) return List_Id; -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the -- aggregate. Target is an expression containing the location on which the -- component by component assignments will take place. Returns the list of -- assignments plus all other adjustments needed for tagged and controlled -- types. procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id); -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the -- aggregate (which can only be a record type, this procedure is only used -- for record types). Transform the given aggregate into a sequence of -- assignments performed component by component. procedure Expand_Record_Aggregate (N : Node_Id; Orig_Tag : Node_Id := Empty; Parent_Expr : Node_Id := Empty); -- This is the top level procedure for record aggregate expansion. -- Expansion for record aggregates needs expand aggregates for tagged -- record types. Specifically Expand_Record_Aggregate adds the Tag -- field in front of the Component_Association list that was created -- during resolution by Resolve_Record_Aggregate. -- -- N is the record aggregate node. -- Orig_Tag is the value of the Tag that has to be provided for this -- specific aggregate. It carries the tag corresponding to the type -- of the outermost aggregate during the recursive expansion -- Parent_Expr is the ancestor part of the original extension -- aggregate function Has_Mutable_Components (Typ : Entity_Id) return Boolean; -- Return true if one of the component is of a discriminated type with -- defaults. An aggregate for a type with mutable components must be -- expanded into individual assignments. procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id); -- If the type of the aggregate is a type extension with renamed discrimi- -- nants, we must initialize the hidden discriminants of the parent. -- Otherwise, the target object must not be initialized. The discriminants -- are initialized by calling the initialization procedure for the type. -- This is incorrect if the initialization of other components has any -- side effects. We restrict this call to the case where the parent type -- has a variant part, because this is the only case where the hidden -- discriminants are accessed, namely when calling discriminant checking -- functions of the parent type, and when applying a stream attribute to -- an object of the derived type. ----------------------------------------------------- -- Local Subprograms for Array Aggregate Expansion -- ----------------------------------------------------- function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean; -- Very large static aggregates present problems to the back-end, and are -- transformed into assignments and loops. This function verifies that the -- total number of components of an aggregate is acceptable for rewriting -- into a purely positional static form. Aggr_Size_OK must be called before -- calling Flatten. -- -- This function also detects and warns about one-component aggregates that -- appear in a non-static context. Even if the component value is static, -- such an aggregate must be expanded into an assignment. function Backend_Processing_Possible (N : Node_Id) return Boolean; -- This function checks if array aggregate N can be processed directly -- by the backend. If this is the case True is returned. function Build_Array_Aggr_Code (N : Node_Id; Ctype : Entity_Id; Index : Node_Id; Into : Node_Id; Scalar_Comp : Boolean; Indexes : List_Id := No_List) return List_Id; -- This recursive routine returns a list of statements containing the -- loops and assignments that are needed for the expansion of the array -- aggregate N. -- -- N is the (sub-)aggregate node to be expanded into code. This node has -- been fully analyzed, and its Etype is properly set. -- -- Index is the index node corresponding to the array sub-aggregate N -- -- Into is the target expression into which we are copying the aggregate. -- Note that this node may not have been analyzed yet, and so the Etype -- field may not be set. -- -- Scalar_Comp is True if the component type of the aggregate is scalar -- -- Indexes is the current list of expressions used to index the object we -- are writing into. procedure Convert_Array_Aggr_In_Allocator (Decl : Node_Id; Aggr : Node_Id; Target : Node_Id); -- If the aggregate appears within an allocator and can be expanded in -- place, this routine generates the individual assignments to components -- of the designated object. This is an optimization over the general -- case, where a temporary is first created on the stack and then used to -- construct the allocated object on the heap. procedure Convert_To_Positional (N : Node_Id; Max_Others_Replicate : Nat := 5; Handle_Bit_Packed : Boolean := False); -- If possible, convert named notation to positional notation. This -- conversion is possible only in some static cases. If the conversion is -- possible, then N is rewritten with the analyzed converted aggregate. -- The parameter Max_Others_Replicate controls the maximum number of -- values corresponding to an others choice that will be converted to -- positional notation (the default of 5 is the normal limit, and reflects -- the fact that normally the loop is better than a lot of separate -- assignments). Note that this limit gets overridden in any case if -- either of the restrictions No_Elaboration_Code or No_Implicit_Loops is -- set. The parameter Handle_Bit_Packed is usually set False (since we do -- not expect the back end to handle bit packed arrays, so the normal case -- of conversion is pointless), but in the special case of a call from -- Packed_Array_Aggregate_Handled, we set this parameter to True, since -- these are cases we handle in there. -- It would seem worthwhile to have a higher default value for Max_Others_ -- replicate, but aggregates in the compiler make this impossible: the -- compiler bootstrap fails if Max_Others_Replicate is greater than 25. -- This is unexpected ??? procedure Expand_Array_Aggregate (N : Node_Id); -- This is the top-level routine to perform array aggregate expansion. -- N is the N_Aggregate node to be expanded. function Late_Expansion (N : Node_Id; Typ : Entity_Id; Target : Node_Id) return List_Id; -- This routine implements top-down expansion of nested aggregates. In -- doing so, it avoids the generation of temporaries at each level. N is -- a nested record or array aggregate with the Expansion_Delayed flag. -- Typ is the expected type of the aggregate. Target is a (duplicatable) -- expression that will hold the result of the aggregate expansion. function Make_OK_Assignment_Statement (Sloc : Source_Ptr; Name : Node_Id; Expression : Node_Id) return Node_Id; -- This is like Make_Assignment_Statement, except that Assignment_OK -- is set in the left operand. All assignments built by this unit use -- this routine. This is needed to deal with assignments to initialized -- constants that are done in place. function Number_Of_Choices (N : Node_Id) return Nat; -- Returns the number of discrete choices (not including the others choice -- if present) contained in (sub-)aggregate N. function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean; -- Given an array aggregate, this function handles the case of a packed -- array aggregate with all constant values, where the aggregate can be -- evaluated at compile time. If this is possible, then N is rewritten -- to be its proper compile time value with all the components properly -- assembled. The expression is analyzed and resolved and True is returned. -- If this transformation is not possible, N is unchanged and False is -- returned. function Safe_Slice_Assignment (N : Node_Id) return Boolean; -- If a slice assignment has an aggregate with a single others_choice, -- the assignment can be done in place even if bounds are not static, -- by converting it into a loop over the discrete range of the slice. ------------------ -- Aggr_Size_OK -- ------------------ function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is Lo : Node_Id; Hi : Node_Id; Indx : Node_Id; Siz : Int; Lov : Uint; Hiv : Uint; -- The following constant determines the maximum size of an array -- aggregate produced by converting named to positional notation (e.g. -- from others clauses). This avoids running away with attempts to -- convert huge aggregates, which hit memory limits in the backend. -- The normal limit is 5000, but we increase this limit to 2**24 (about -- 16 million) if Restrictions (No_Elaboration_Code) or Restrictions -- (No_Implicit_Loops) is specified, since in either case, we are at -- risk of declaring the program illegal because of this limit. Max_Aggr_Size : constant Nat := 5000 + (2 ** 24 - 5000) * Boolean'Pos (Restriction_Active (No_Elaboration_Code) or else Restriction_Active (No_Implicit_Loops)); function Component_Count (T : Entity_Id) return Int; -- The limit is applied to the total number of components that the -- aggregate will have, which is the number of static expressions -- that will appear in the flattened array. This requires a recursive -- computation of the number of scalar components of the structure. --------------------- -- Component_Count -- --------------------- function Component_Count (T : Entity_Id) return Int is Res : Int := 0; Comp : Entity_Id; begin if Is_Scalar_Type (T) then return 1; elsif Is_Record_Type (T) then Comp := First_Component (T); while Present (Comp) loop Res := Res + Component_Count (Etype (Comp)); Next_Component (Comp); end loop; return Res; elsif Is_Array_Type (T) then declare Lo : constant Node_Id := Type_Low_Bound (Etype (First_Index (T))); Hi : constant Node_Id := Type_High_Bound (Etype (First_Index (T))); Siz : constant Int := Component_Count (Component_Type (T)); begin if not Compile_Time_Known_Value (Lo) or else not Compile_Time_Known_Value (Hi) then return 0; else return Siz * UI_To_Int (Expr_Value (Hi) - Expr_Value (Lo) + 1); end if; end; else -- Can only be a null for an access type return 1; end if; end Component_Count; -- Start of processing for Aggr_Size_OK begin Siz := Component_Count (Component_Type (Typ)); Indx := First_Index (Typ); while Present (Indx) loop Lo := Type_Low_Bound (Etype (Indx)); Hi := Type_High_Bound (Etype (Indx)); -- Bounds need to be known at compile time if not Compile_Time_Known_Value (Lo) or else not Compile_Time_Known_Value (Hi) then return False; end if; Lov := Expr_Value (Lo); Hiv := Expr_Value (Hi); -- A flat array is always safe if Hiv < Lov then return True; end if; -- One-component aggregates are suspicious, and if the context type -- is an object declaration with non-static bounds it will trip gcc; -- such an aggregate must be expanded into a single assignment. if Hiv = Lov and then Nkind (Parent (N)) = N_Object_Declaration then declare Index_Type : constant Entity_Id := Etype (First_Index (Etype (Defining_Identifier (Parent (N))))); Indx : Node_Id; begin if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type)) or else not Compile_Time_Known_Value (Type_High_Bound (Index_Type)) then if Present (Component_Associations (N)) then Indx := First (Choices (First (Component_Associations (N)))); if Is_Entity_Name (Indx) and then not Is_Type (Entity (Indx)) then Error_Msg_N ("single component aggregate in non-static context?", Indx); Error_Msg_N ("\maybe subtype name was meant?", Indx); end if; end if; return False; end if; end; end if; declare Rng : constant Uint := Hiv - Lov + 1; begin -- Check if size is too large if not UI_Is_In_Int_Range (Rng) then return False; end if; Siz := Siz * UI_To_Int (Rng); end; if Siz <= 0 or else Siz > Max_Aggr_Size then return False; end if; -- Bounds must be in integer range, for later array construction if not UI_Is_In_Int_Range (Lov) or else not UI_Is_In_Int_Range (Hiv) then return False; end if; Next_Index (Indx); end loop; return True; end Aggr_Size_OK; --------------------------------- -- Backend_Processing_Possible -- --------------------------------- -- Backend processing by Gigi/gcc is possible only if all the following -- conditions are met: -- 1. N is fully positional -- 2. N is not a bit-packed array aggregate; -- 3. The size of N's array type must be known at compile time. Note -- that this implies that the component size is also known -- 4. The array type of N does not follow the Fortran layout convention -- or if it does it must be 1 dimensional. -- 5. The array component type may not be tagged (which could necessitate -- reassignment of proper tags). -- 6. The array component type must not have unaligned bit components -- 7. None of the components of the aggregate may be bit unaligned -- components. -- 8. There cannot be delayed components, since we do not know enough -- at this stage to know if back end processing is possible. -- 9. There cannot be any discriminated record components, since the -- back end cannot handle this complex case. -- 10. No controlled actions need to be generated for components -- 11. For a VM back end, the array should have no aliased components function Backend_Processing_Possible (N : Node_Id) return Boolean is Typ : constant Entity_Id := Etype (N); -- Typ is the correct constrained array subtype of the aggregate function Component_Check (N : Node_Id; Index : Node_Id) return Boolean; -- This routine checks components of aggregate N, enforcing checks -- 1, 7, 8, and 9. In the multi-dimensional case, these checks are -- performed on subaggregates. The Index value is the current index -- being checked in the multi-dimensional case. --------------------- -- Component_Check -- --------------------- function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is Expr : Node_Id; begin -- Checks 1: (no component associations) if Present (Component_Associations (N)) then return False; end if; -- Checks on components -- Recurse to check subaggregates, which may appear in qualified -- expressions. If delayed, the front-end will have to expand. -- If the component is a discriminated record, treat as non-static, -- as the back-end cannot handle this properly. Expr := First (Expressions (N)); while Present (Expr) loop -- Checks 8: (no delayed components) if Is_Delayed_Aggregate (Expr) then return False; end if; -- Checks 9: (no discriminated records) if Present (Etype (Expr)) and then Is_Record_Type (Etype (Expr)) and then Has_Discriminants (Etype (Expr)) then return False; end if; -- Checks 7. Component must not be bit aligned component if Possible_Bit_Aligned_Component (Expr) then return False; end if; -- Recursion to following indexes for multiple dimension case if Present (Next_Index (Index)) and then not Component_Check (Expr, Next_Index (Index)) then return False; end if; -- All checks for that component finished, on to next Next (Expr); end loop; return True; end Component_Check; -- Start of processing for Backend_Processing_Possible begin -- Checks 2 (array not bit packed) and 10 (no controlled actions) if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then return False; end if; -- If component is limited, aggregate must be expanded because each -- component assignment must be built in place. if Is_Immutably_Limited_Type (Component_Type (Typ)) then return False; end if; -- Checks 4 (array must not be multi-dimensional Fortran case) if Convention (Typ) = Convention_Fortran and then Number_Dimensions (Typ) > 1 then return False; end if; -- Checks 3 (size of array must be known at compile time) if not Size_Known_At_Compile_Time (Typ) then return False; end if; -- Checks on components if not Component_Check (N, First_Index (Typ)) then return False; end if; -- Checks 5 (if the component type is tagged, then we may need to do -- tag adjustments. Perhaps this should be refined to check for any -- component associations that actually need tag adjustment, similar -- to the test in Component_Not_OK_For_Backend for record aggregates -- with tagged components, but not clear whether it's worthwhile ???; -- in the case of the JVM, object tags are handled implicitly) if Is_Tagged_Type (Component_Type (Typ)) and then Tagged_Type_Expansion then return False; end if; -- Checks 6 (component type must not have bit aligned components) if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then return False; end if; -- Checks 11: Array aggregates with aliased components are currently -- not well supported by the VM backend; disable temporarily this -- backend processing until it is definitely supported. if VM_Target /= No_VM and then Has_Aliased_Components (Base_Type (Typ)) then return False; end if; -- Backend processing is possible Set_Size_Known_At_Compile_Time (Etype (N), True); return True; end Backend_Processing_Possible; --------------------------- -- Build_Array_Aggr_Code -- --------------------------- -- The code that we generate from a one dimensional aggregate is -- 1. If the sub-aggregate contains discrete choices we -- (a) Sort the discrete choices -- (b) Otherwise for each discrete choice that specifies a range we -- emit a loop. If a range specifies a maximum of three values, or -- we are dealing with an expression we emit a sequence of -- assignments instead of a loop. -- (c) Generate the remaining loops to cover the others choice if any -- 2. If the aggregate contains positional elements we -- (a) translate the positional elements in a series of assignments -- (b) Generate a final loop to cover the others choice if any. -- Note that this final loop has to be a while loop since the case -- L : Integer := Integer'Last; -- H : Integer := Integer'Last; -- A : array (L .. H) := (1, others =>0); -- cannot be handled by a for loop. Thus for the following -- array (L .. H) := (.. positional elements.., others =>E); -- we always generate something like: -- J : Index_Type := Index_Of_Last_Positional_Element; -- while J < H loop -- J := Index_Base'Succ (J) -- Tmp (J) := E; -- end loop; function Build_Array_Aggr_Code (N : Node_Id; Ctype : Entity_Id; Index : Node_Id; Into : Node_Id; Scalar_Comp : Boolean; Indexes : List_Id := No_List) return List_Id is Loc : constant Source_Ptr := Sloc (N); Index_Base : constant Entity_Id := Base_Type (Etype (Index)); Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base); Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base); function Add (Val : Int; To : Node_Id) return Node_Id; -- Returns an expression where Val is added to expression To, unless -- To+Val is provably out of To's base type range. To must be an -- already analyzed expression. function Empty_Range (L, H : Node_Id) return Boolean; -- Returns True if the range defined by L .. H is certainly empty function Equal (L, H : Node_Id) return Boolean; -- Returns True if L = H for sure function Index_Base_Name return Node_Id; -- Returns a new reference to the index type name function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id; -- Ind must be a side-effect free expression. If the input aggregate -- N to Build_Loop contains no sub-aggregates, then this function -- returns the assignment statement: -- -- Into (Indexes, Ind) := Expr; -- -- Otherwise we call Build_Code recursively -- -- Ada 2005 (AI-287): In case of default initialized component, Expr -- is empty and we generate a call to the corresponding IP subprogram. function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id; -- Nodes L and H must be side-effect free expressions. -- If the input aggregate N to Build_Loop contains no sub-aggregates, -- This routine returns the for loop statement -- -- for J in Index_Base'(L) .. Index_Base'(H) loop -- Into (Indexes, J) := Expr; -- end loop; -- -- Otherwise we call Build_Code recursively. -- As an optimization if the loop covers 3 or less scalar elements we -- generate a sequence of assignments. function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id; -- Nodes L and H must be side-effect free expressions. -- If the input aggregate N to Build_Loop contains no sub-aggregates, -- This routine returns the while loop statement -- -- J : Index_Base := L; -- while J < H loop -- J := Index_Base'Succ (J); -- Into (Indexes, J) := Expr; -- end loop; -- -- Otherwise we call Build_Code recursively function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean; function Local_Expr_Value (E : Node_Id) return Uint; -- These two Local routines are used to replace the corresponding ones -- in sem_eval because while processing the bounds of an aggregate with -- discrete choices whose index type is an enumeration, we build static -- expressions not recognized by Compile_Time_Known_Value as such since -- they have not yet been analyzed and resolved. All the expressions in -- question are things like Index_Base_Name'Val (Const) which we can -- easily recognize as being constant. --------- -- Add -- --------- function Add (Val : Int; To : Node_Id) return Node_Id is Expr_Pos : Node_Id; Expr : Node_Id; To_Pos : Node_Id; U_To : Uint; U_Val : constant Uint := UI_From_Int (Val); begin -- Note: do not try to optimize the case of Val = 0, because -- we need to build a new node with the proper Sloc value anyway. -- First test if we can do constant folding if Local_Compile_Time_Known_Value (To) then U_To := Local_Expr_Value (To) + Val; -- Determine if our constant is outside the range of the index. -- If so return an Empty node. This empty node will be caught -- by Empty_Range below. if Compile_Time_Known_Value (Index_Base_L) and then U_To < Expr_Value (Index_Base_L) then return Empty; elsif Compile_Time_Known_Value (Index_Base_H) and then U_To > Expr_Value (Index_Base_H) then return Empty; end if; Expr_Pos := Make_Integer_Literal (Loc, U_To); Set_Is_Static_Expression (Expr_Pos); if not Is_Enumeration_Type (Index_Base) then Expr := Expr_Pos; -- If we are dealing with enumeration return -- Index_Base'Val (Expr_Pos) else Expr := Make_Attribute_Reference (Loc, Prefix => Index_Base_Name, Attribute_Name => Name_Val, Expressions => New_List (Expr_Pos)); end if; return Expr; end if; -- If we are here no constant folding possible if not Is_Enumeration_Type (Index_Base) then Expr := Make_Op_Add (Loc, Left_Opnd => Duplicate_Subexpr (To), Right_Opnd => Make_Integer_Literal (Loc, U_Val)); -- If we are dealing with enumeration return -- Index_Base'Val (Index_Base'Pos (To) + Val) else To_Pos := Make_Attribute_Reference (Loc, Prefix => Index_Base_Name, Attribute_Name => Name_Pos, Expressions => New_List (Duplicate_Subexpr (To))); Expr_Pos := Make_Op_Add (Loc, Left_Opnd => To_Pos, Right_Opnd => Make_Integer_Literal (Loc, U_Val)); Expr := Make_Attribute_Reference (Loc, Prefix => Index_Base_Name, Attribute_Name => Name_Val, Expressions => New_List (Expr_Pos)); end if; return Expr; end Add; ----------------- -- Empty_Range -- ----------------- function Empty_Range (L, H : Node_Id) return Boolean is Is_Empty : Boolean := False; Low : Node_Id; High : Node_Id; begin -- First check if L or H were already detected as overflowing the -- index base range type by function Add above. If this is so Add -- returns the empty node. if No (L) or else No (H) then return True; end if; for J in 1 .. 3 loop case J is -- L > H range is empty when 1 => Low := L; High := H; -- B_L > H range must be empty when 2 => Low := Index_Base_L; High := H; -- L > B_H range must be empty when 3 => Low := L; High := Index_Base_H; end case; if Local_Compile_Time_Known_Value (Low) and then Local_Compile_Time_Known_Value (High) then Is_Empty := UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High)); end if; exit when Is_Empty; end loop; return Is_Empty; end Empty_Range; ----------- -- Equal -- ----------- function Equal (L, H : Node_Id) return Boolean is begin if L = H then return True; elsif Local_Compile_Time_Known_Value (L) and then Local_Compile_Time_Known_Value (H) then return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H)); end if; return False; end Equal; ---------------- -- Gen_Assign -- ---------------- function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id is L : constant List_Id := New_List; A : Node_Id; New_Indexes : List_Id; Indexed_Comp : Node_Id; Expr_Q : Node_Id; Comp_Type : Entity_Id := Empty; function Add_Loop_Actions (Lis : List_Id) return List_Id; -- Collect insert_actions generated in the construction of a -- loop, and prepend them to the sequence of assignments to -- complete the eventual body of the loop. ---------------------- -- Add_Loop_Actions -- ---------------------- function Add_Loop_Actions (Lis : List_Id) return List_Id is Res : List_Id; begin -- Ada 2005 (AI-287): Do nothing else in case of default -- initialized component. if No (Expr) then return Lis; elsif Nkind (Parent (Expr)) = N_Component_Association and then Present (Loop_Actions (Parent (Expr))) then Append_List (Lis, Loop_Actions (Parent (Expr))); Res := Loop_Actions (Parent (Expr)); Set_Loop_Actions (Parent (Expr), No_List); return Res; else return Lis; end if; end Add_Loop_Actions; -- Start of processing for Gen_Assign begin if No (Indexes) then New_Indexes := New_List; else New_Indexes := New_Copy_List_Tree (Indexes); end if; Append_To (New_Indexes, Ind); if Present (Next_Index (Index)) then return Add_Loop_Actions ( Build_Array_Aggr_Code (N => Expr, Ctype => Ctype, Index => Next_Index (Index), Into => Into, Scalar_Comp => Scalar_Comp, Indexes => New_Indexes)); end if; -- If we get here then we are at a bottom-level (sub-)aggregate Indexed_Comp := Checks_Off (Make_Indexed_Component (Loc, Prefix => New_Copy_Tree (Into), Expressions => New_Indexes)); Set_Assignment_OK (Indexed_Comp); -- Ada 2005 (AI-287): In case of default initialized component, Expr -- is not present (and therefore we also initialize Expr_Q to empty). if No (Expr) then Expr_Q := Empty; elsif Nkind (Expr) = N_Qualified_Expression then Expr_Q := Expression (Expr); else Expr_Q := Expr; end if; if Present (Etype (N)) and then Etype (N) /= Any_Composite then Comp_Type := Component_Type (Etype (N)); pragma Assert (Comp_Type = Ctype); -- AI-287 elsif Present (Next (First (New_Indexes))) then -- Ada 2005 (AI-287): Do nothing in case of default initialized -- component because we have received the component type in -- the formal parameter Ctype. -- ??? Some assert pragmas have been added to check if this new -- formal can be used to replace this code in all cases. if Present (Expr) then -- This is a multidimensional array. Recover the component -- type from the outermost aggregate, because subaggregates -- do not have an assigned type. declare P : Node_Id; begin P := Parent (Expr); while Present (P) loop if Nkind (P) = N_Aggregate and then Present (Etype (P)) then Comp_Type := Component_Type (Etype (P)); exit; else P := Parent (P); end if; end loop; pragma Assert (Comp_Type = Ctype); -- AI-287 end; end if; end if; -- Ada 2005 (AI-287): We only analyze the expression in case of non- -- default initialized components (otherwise Expr_Q is not present). if Present (Expr_Q) and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate) then -- At this stage the Expression may not have been analyzed yet -- because the array aggregate code has not been updated to use -- the Expansion_Delayed flag and avoid analysis altogether to -- solve the same problem (see Resolve_Aggr_Expr). So let us do -- the analysis of non-array aggregates now in order to get the -- value of Expansion_Delayed flag for the inner aggregate ??? if Present (Comp_Type) and then not Is_Array_Type (Comp_Type) then Analyze_And_Resolve (Expr_Q, Comp_Type); end if; if Is_Delayed_Aggregate (Expr_Q) then -- This is either a subaggregate of a multidimensional array, -- or a component of an array type whose component type is -- also an array. In the latter case, the expression may have -- component associations that provide different bounds from -- those of the component type, and sliding must occur. Instead -- of decomposing the current aggregate assignment, force the -- re-analysis of the assignment, so that a temporary will be -- generated in the usual fashion, and sliding will take place. if Nkind (Parent (N)) = N_Assignment_Statement and then Is_Array_Type (Comp_Type) and then Present (Component_Associations (Expr_Q)) and then Must_Slide (Comp_Type, Etype (Expr_Q)) then Set_Expansion_Delayed (Expr_Q, False); Set_Analyzed (Expr_Q, False); else return Add_Loop_Actions ( Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp)); end if; end if; end if; -- Ada 2005 (AI-287): In case of default initialized component, call -- the initialization subprogram associated with the component type. -- If the component type is an access type, add an explicit null -- assignment, because for the back-end there is an initialization -- present for the whole aggregate, and no default initialization -- will take place. -- In addition, if the component type is controlled, we must call -- its Initialize procedure explicitly, because there is no explicit -- object creation that will invoke it otherwise. if No (Expr) then if Present (Base_Init_Proc (Base_Type (Ctype))) or else Has_Task (Base_Type (Ctype)) then Append_List_To (L, Build_Initialization_Call (Loc, Id_Ref => Indexed_Comp, Typ => Ctype, With_Default_Init => True)); elsif Is_Access_Type (Ctype) then Append_To (L, Make_Assignment_Statement (Loc, Name => Indexed_Comp, Expression => Make_Null (Loc))); end if; if Needs_Finalization (Ctype) then Append_To (L, Make_Init_Call ( Obj_Ref => New_Copy_Tree (Indexed_Comp), Typ => Ctype)); end if; else -- Now generate the assignment with no associated controlled -- actions since the target of the assignment may not have been -- initialized, it is not possible to Finalize it as expected by -- normal controlled assignment. The rest of the controlled -- actions are done manually with the proper finalization list -- coming from the context. A := Make_OK_Assignment_Statement (Loc, Name => Indexed_Comp, Expression => New_Copy_Tree (Expr)); if Present (Comp_Type) and then Needs_Finalization (Comp_Type) then Set_No_Ctrl_Actions (A); -- If this is an aggregate for an array of arrays, each -- sub-aggregate will be expanded as well, and even with -- No_Ctrl_Actions the assignments of inner components will -- require attachment in their assignments to temporaries. -- These temporaries must be finalized for each subaggregate, -- to prevent multiple attachments of the same temporary -- location to same finalization chain (and consequently -- circular lists). To ensure that finalization takes place -- for each subaggregate we wrap the assignment in a block. if Is_Array_Type (Comp_Type) and then Nkind (Expr) = N_Aggregate then A := Make_Block_Statement (Loc, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => New_List (A))); end if; end if; Append_To (L, A); -- Adjust the tag if tagged (because of possible view -- conversions), unless compiling for a VM where -- tags are implicit. if Present (Comp_Type) and then Is_Tagged_Type (Comp_Type) and then Tagged_Type_Expansion then declare Full_Typ : constant Entity_Id := Underlying_Type (Comp_Type); begin A := Make_OK_Assignment_Statement (Loc, Name => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Indexed_Comp), Selector_Name => New_Reference_To (First_Tag_Component (Full_Typ), Loc)), Expression => Unchecked_Convert_To (RTE (RE_Tag), New_Reference_To (Node (First_Elmt (Access_Disp_Table (Full_Typ))), Loc))); Append_To (L, A); end; end if; -- Adjust and attach the component to the proper final list, which -- can be the controller of the outer record object or the final -- list associated with the scope. -- If the component is itself an array of controlled types, whose -- value is given by a sub-aggregate, then the attach calls have -- been generated when individual subcomponent are assigned, and -- must not be done again to prevent malformed finalization chains -- (see comments above, concerning the creation of a block to hold -- inner finalization actions). if Present (Comp_Type) and then Needs_Finalization (Comp_Type) and then not Is_Limited_Type (Comp_Type) and then not (Is_Array_Type (Comp_Type) and then Is_Controlled (Component_Type (Comp_Type)) and then Nkind (Expr) = N_Aggregate) then Append_To (L, Make_Adjust_Call ( Obj_Ref => New_Copy_Tree (Indexed_Comp), Typ => Comp_Type)); end if; end if; return Add_Loop_Actions (L); end Gen_Assign; -------------- -- Gen_Loop -- -------------- function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is L_J : Node_Id; L_L : Node_Id; -- Index_Base'(L) L_H : Node_Id; -- Index_Base'(H) L_Range : Node_Id; -- Index_Base'(L) .. Index_Base'(H) L_Iteration_Scheme : Node_Id; -- L_J in Index_Base'(L) .. Index_Base'(H) L_Body : List_Id; -- The statements to execute in the loop S : constant List_Id := New_List; -- List of statements Tcopy : Node_Id; -- Copy of expression tree, used for checking purposes begin -- If loop bounds define an empty range return the null statement if Empty_Range (L, H) then Append_To (S, Make_Null_Statement (Loc)); -- Ada 2005 (AI-287): Nothing else need to be done in case of -- default initialized component. if No (Expr) then null; else -- The expression must be type-checked even though no component -- of the aggregate will have this value. This is done only for -- actual components of the array, not for subaggregates. Do -- the check on a copy, because the expression may be shared -- among several choices, some of which might be non-null. if Present (Etype (N)) and then Is_Array_Type (Etype (N)) and then No (Next_Index (Index)) then Expander_Mode_Save_And_Set (False); Tcopy := New_Copy_Tree (Expr); Set_Parent (Tcopy, N); Analyze_And_Resolve (Tcopy, Component_Type (Etype (N))); Expander_Mode_Restore; end if; end if; return S; -- If loop bounds are the same then generate an assignment elsif Equal (L, H) then return Gen_Assign (New_Copy_Tree (L), Expr); -- If H - L <= 2 then generate a sequence of assignments when we are -- processing the bottom most aggregate and it contains scalar -- components. elsif No (Next_Index (Index)) and then Scalar_Comp and then Local_Compile_Time_Known_Value (L) and then Local_Compile_Time_Known_Value (H) and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2 then Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr)); Append_List_To (S, Gen_Assign (Add (1, To => L), Expr)); if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then Append_List_To (S, Gen_Assign (Add (2, To => L), Expr)); end if; return S; end if; -- Otherwise construct the loop, starting with the loop index L_J L_J := Make_Temporary (Loc, 'J', L); -- Construct "L .. H" in Index_Base. We use a qualified expression -- for the bound to convert to the index base, but we don't need -- to do that if we already have the base type at hand. if Etype (L) = Index_Base then L_L := L; else L_L := Make_Qualified_Expression (Loc, Subtype_Mark => Index_Base_Name, Expression => L); end if; if Etype (H) = Index_Base then L_H := H; else L_H := Make_Qualified_Expression (Loc, Subtype_Mark => Index_Base_Name, Expression => H); end if; L_Range := Make_Range (Loc, Low_Bound => L_L, High_Bound => L_H); -- Construct "for L_J in Index_Base range L .. H" L_Iteration_Scheme := Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => L_J, Discrete_Subtype_Definition => L_Range)); -- Construct the statements to execute in the loop body L_Body := Gen_Assign (New_Reference_To (L_J, Loc), Expr); -- Construct the final loop Append_To (S, Make_Implicit_Loop_Statement (Node => N, Identifier => Empty, Iteration_Scheme => L_Iteration_Scheme, Statements => L_Body)); -- A small optimization: if the aggregate is initialized with a box -- and the component type has no initialization procedure, remove the -- useless empty loop. if Nkind (First (S)) = N_Loop_Statement and then Is_Empty_List (Statements (First (S))) then return New_List (Make_Null_Statement (Loc)); else return S; end if; end Gen_Loop; --------------- -- Gen_While -- --------------- -- The code built is -- W_J : Index_Base := L; -- while W_J < H loop -- W_J := Index_Base'Succ (W); -- L_Body; -- end loop; function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is W_J : Node_Id; W_Decl : Node_Id; -- W_J : Base_Type := L; W_Iteration_Scheme : Node_Id; -- while W_J < H W_Index_Succ : Node_Id; -- Index_Base'Succ (J) W_Increment : Node_Id; -- W_J := Index_Base'Succ (W) W_Body : constant List_Id := New_List; -- The statements to execute in the loop S : constant List_Id := New_List; -- list of statement begin -- If loop bounds define an empty range or are equal return null if Empty_Range (L, H) or else Equal (L, H) then Append_To (S, Make_Null_Statement (Loc)); return S; end if; -- Build the decl of W_J W_J := Make_Temporary (Loc, 'J', L); W_Decl := Make_Object_Declaration (Loc, Defining_Identifier => W_J, Object_Definition => Index_Base_Name, Expression => L); -- Theoretically we should do a New_Copy_Tree (L) here, but we know -- that in this particular case L is a fresh Expr generated by -- Add which we are the only ones to use. Append_To (S, W_Decl); -- Construct " while W_J < H" W_Iteration_Scheme := Make_Iteration_Scheme (Loc, Condition => Make_Op_Lt (Loc, Left_Opnd => New_Reference_To (W_J, Loc), Right_Opnd => New_Copy_Tree (H))); -- Construct the statements to execute in the loop body W_Index_Succ := Make_Attribute_Reference (Loc, Prefix => Index_Base_Name, Attribute_Name => Name_Succ, Expressions => New_List (New_Reference_To (W_J, Loc))); W_Increment := Make_OK_Assignment_Statement (Loc, Name => New_Reference_To (W_J, Loc), Expression => W_Index_Succ); Append_To (W_Body, W_Increment); Append_List_To (W_Body, Gen_Assign (New_Reference_To (W_J, Loc), Expr)); -- Construct the final loop Append_To (S, Make_Implicit_Loop_Statement (Node => N, Identifier => Empty, Iteration_Scheme => W_Iteration_Scheme, Statements => W_Body)); return S; end Gen_While; --------------------- -- Index_Base_Name -- --------------------- function Index_Base_Name return Node_Id is begin return New_Reference_To (Index_Base, Sloc (N)); end Index_Base_Name; ------------------------------------ -- Local_Compile_Time_Known_Value -- ------------------------------------ function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is begin return Compile_Time_Known_Value (E) or else (Nkind (E) = N_Attribute_Reference and then Attribute_Name (E) = Name_Val and then Compile_Time_Known_Value (First (Expressions (E)))); end Local_Compile_Time_Known_Value; ---------------------- -- Local_Expr_Value -- ---------------------- function Local_Expr_Value (E : Node_Id) return Uint is begin if Compile_Time_Known_Value (E) then return Expr_Value (E); else return Expr_Value (First (Expressions (E))); end if; end Local_Expr_Value; -- Build_Array_Aggr_Code Variables Assoc : Node_Id; Choice : Node_Id; Expr : Node_Id; Typ : Entity_Id; Others_Expr : Node_Id := Empty; Others_Box_Present : Boolean := False; Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N)); Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N)); -- The aggregate bounds of this specific sub-aggregate. Note that if -- the code generated by Build_Array_Aggr_Code is executed then these -- bounds are OK. Otherwise a Constraint_Error would have been raised. Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L); Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H); -- After Duplicate_Subexpr these are side-effect free Low : Node_Id; High : Node_Id; Nb_Choices : Nat := 0; Table : Case_Table_Type (1 .. Number_Of_Choices (N)); -- Used to sort all the different choice values Nb_Elements : Int; -- Number of elements in the positional aggregate New_Code : constant List_Id := New_List; -- Start of processing for Build_Array_Aggr_Code begin -- First before we start, a special case. if we have a bit packed -- array represented as a modular type, then clear the value to -- zero first, to ensure that unused bits are properly cleared. Typ := Etype (N); if Present (Typ) and then Is_Bit_Packed_Array (Typ) and then Is_Modular_Integer_Type (Packed_Array_Type (Typ)) then Append_To (New_Code, Make_Assignment_Statement (Loc, Name => New_Copy_Tree (Into), Expression => Unchecked_Convert_To (Typ, Make_Integer_Literal (Loc, Uint_0)))); end if; -- If the component type contains tasks, we need to build a Master -- entity in the current scope, because it will be needed if build- -- in-place functions are called in the expanded code. if Nkind (Parent (N)) = N_Object_Declaration and then Has_Task (Typ) then Build_Master_Entity (Defining_Identifier (Parent (N))); end if; -- STEP 1: Process component associations -- For those associations that may generate a loop, initialize -- Loop_Actions to collect inserted actions that may be crated. -- Skip this if no component associations if No (Expressions (N)) then -- STEP 1 (a): Sort the discrete choices Assoc := First (Component_Associations (N)); while Present (Assoc) loop Choice := First (Choices (Assoc)); while Present (Choice) loop if Nkind (Choice) = N_Others_Choice then Set_Loop_Actions (Assoc, New_List); if Box_Present (Assoc) then Others_Box_Present := True; else Others_Expr := Expression (Assoc); end if; exit; end if; Get_Index_Bounds (Choice, Low, High); if Low /= High then Set_Loop_Actions (Assoc, New_List); end if; Nb_Choices := Nb_Choices + 1; if Box_Present (Assoc) then Table (Nb_Choices) := (Choice_Lo => Low, Choice_Hi => High, Choice_Node => Empty); else Table (Nb_Choices) := (Choice_Lo => Low, Choice_Hi => High, Choice_Node => Expression (Assoc)); end if; Next (Choice); end loop; Next (Assoc); end loop; -- If there is more than one set of choices these must be static -- and we can therefore sort them. Remember that Nb_Choices does not -- account for an others choice. if Nb_Choices > 1 then Sort_Case_Table (Table); end if; -- STEP 1 (b): take care of the whole set of discrete choices for J in 1 .. Nb_Choices loop Low := Table (J).Choice_Lo; High := Table (J).Choice_Hi; Expr := Table (J).Choice_Node; Append_List (Gen_Loop (Low, High, Expr), To => New_Code); end loop; -- STEP 1 (c): generate the remaining loops to cover others choice -- We don't need to generate loops over empty gaps, but if there is -- a single empty range we must analyze the expression for semantics if Present (Others_Expr) or else Others_Box_Present then declare First : Boolean := True; begin for J in 0 .. Nb_Choices loop if J = 0 then Low := Aggr_Low; else Low := Add (1, To => Table (J).Choice_Hi); end if; if J = Nb_Choices then High := Aggr_High; else High := Add (-1, To => Table (J + 1).Choice_Lo); end if; -- If this is an expansion within an init proc, make -- sure that discriminant references are replaced by -- the corresponding discriminal. if Inside_Init_Proc then if Is_Entity_Name (Low) and then Ekind (Entity (Low)) = E_Discriminant then Set_Entity (Low, Discriminal (Entity (Low))); end if; if Is_Entity_Name (High) and then Ekind (Entity (High)) = E_Discriminant then Set_Entity (High, Discriminal (Entity (High))); end if; end if; if First or else not Empty_Range (Low, High) then First := False; Append_List (Gen_Loop (Low, High, Others_Expr), To => New_Code); end if; end loop; end; end if; -- STEP 2: Process positional components else -- STEP 2 (a): Generate the assignments for each positional element -- Note that here we have to use Aggr_L rather than Aggr_Low because -- Aggr_L is analyzed and Add wants an analyzed expression. Expr := First (Expressions (N)); Nb_Elements := -1; while Present (Expr) loop Nb_Elements := Nb_Elements + 1; Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr), To => New_Code); Next (Expr); end loop; -- STEP 2 (b): Generate final loop if an others choice is present -- Here Nb_Elements gives the offset of the last positional element. if Present (Component_Associations (N)) then Assoc := Last (Component_Associations (N)); -- Ada 2005 (AI-287) if Box_Present (Assoc) then Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L), Aggr_High, Empty), To => New_Code); else Expr := Expression (Assoc); Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L), Aggr_High, Expr), -- AI-287 To => New_Code); end if; end if; end if; return New_Code; end Build_Array_Aggr_Code; ---------------------------- -- Build_Record_Aggr_Code -- ---------------------------- function Build_Record_Aggr_Code (N : Node_Id; Typ : Entity_Id; Lhs : Node_Id) return List_Id is Loc : constant Source_Ptr := Sloc (N); L : constant List_Id := New_List; N_Typ : constant Entity_Id := Etype (N); Comp : Node_Id; Instr : Node_Id; Ref : Node_Id; Target : Entity_Id; Comp_Type : Entity_Id; Selector : Entity_Id; Comp_Expr : Node_Id; Expr_Q : Node_Id; -- If this is an internal aggregate, the External_Final_List is an -- expression for the controller record of the enclosing type. -- If the current aggregate has several controlled components, this -- expression will appear in several calls to attach to the finali- -- zation list, and it must not be shared. Ancestor_Is_Expression : Boolean := False; Ancestor_Is_Subtype_Mark : Boolean := False; Init_Typ : Entity_Id := Empty; Finalization_Done : Boolean := False; -- True if Generate_Finalization_Actions has already been called; calls -- after the first do nothing. function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id; -- Returns the value that the given discriminant of an ancestor type -- should receive (in the absence of a conflict with the value provided -- by an ancestor part of an extension aggregate). procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id); -- Check that each of the discriminant values defined by the ancestor -- part of an extension aggregate match the corresponding values -- provided by either an association of the aggregate or by the -- constraint imposed by a parent type (RM95-4.3.2(8)). function Compatible_Int_Bounds (Agg_Bounds : Node_Id; Typ_Bounds : Node_Id) return Boolean; -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is -- assumed that both bounds are integer ranges. procedure Generate_Finalization_Actions; -- Deal with the various controlled type data structure initializations -- (but only if it hasn't been done already). function Get_Constraint_Association (T : Entity_Id) return Node_Id; -- Returns the first discriminant association in the constraint -- associated with T, if any, otherwise returns Empty. procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id); -- If Typ is derived, and constrains discriminants of the parent type, -- these discriminants are not components of the aggregate, and must be -- initialized. The assignments are appended to List. function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean; -- Check whether Bounds is a range node and its lower and higher bounds -- are integers literals. --------------------------------- -- Ancestor_Discriminant_Value -- --------------------------------- function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is Assoc : Node_Id; Assoc_Elmt : Elmt_Id; Aggr_Comp : Entity_Id; Corresp_Disc : Entity_Id; Current_Typ : Entity_Id := Base_Type (Typ); Parent_Typ : Entity_Id; Parent_Disc : Entity_Id; Save_Assoc : Node_Id := Empty; begin -- First check any discriminant associations to see if any of them -- provide a value for the discriminant. if Present (Discriminant_Specifications (Parent (Current_Typ))) then Assoc := First (Component_Associations (N)); while Present (Assoc) loop Aggr_Comp := Entity (First (Choices (Assoc))); if Ekind (Aggr_Comp) = E_Discriminant then Save_Assoc := Expression (Assoc); Corresp_Disc := Corresponding_Discriminant (Aggr_Comp); while Present (Corresp_Disc) loop -- If found a corresponding discriminant then return the -- value given in the aggregate. (Note: this is not -- correct in the presence of side effects. ???) if Disc = Corresp_Disc then return Duplicate_Subexpr (Expression (Assoc)); end if; Corresp_Disc := Corresponding_Discriminant (Corresp_Disc); end loop; end if; Next (Assoc); end loop; end if; -- No match found in aggregate, so chain up parent types to find -- a constraint that defines the value of the discriminant. Parent_Typ := Etype (Current_Typ); while Current_Typ /= Parent_Typ loop if Has_Discriminants (Parent_Typ) and then not Has_Unknown_Discriminants (Parent_Typ) then Parent_Disc := First_Discriminant (Parent_Typ); -- We either get the association from the subtype indication -- of the type definition itself, or from the discriminant -- constraint associated with the type entity (which is -- preferable, but it's not always present ???) if Is_Empty_Elmt_List ( Discriminant_Constraint (Current_Typ)) then Assoc := Get_Constraint_Association (Current_Typ); Assoc_Elmt := No_Elmt; else Assoc_Elmt := First_Elmt (Discriminant_Constraint (Current_Typ)); Assoc := Node (Assoc_Elmt); end if; -- Traverse the discriminants of the parent type looking -- for one that corresponds. while Present (Parent_Disc) and then Present (Assoc) loop Corresp_Disc := Parent_Disc; while Present (Corresp_Disc) and then Disc /= Corresp_Disc loop Corresp_Disc := Corresponding_Discriminant (Corresp_Disc); end loop; if Disc = Corresp_Disc then if Nkind (Assoc) = N_Discriminant_Association then Assoc := Expression (Assoc); end if; -- If the located association directly denotes a -- discriminant, then use the value of a saved -- association of the aggregate. This is a kludge to -- handle certain cases involving multiple discriminants -- mapped to a single discriminant of a descendant. It's -- not clear how to locate the appropriate discriminant -- value for such cases. ??? if Is_Entity_Name (Assoc) and then Ekind (Entity (Assoc)) = E_Discriminant then Assoc := Save_Assoc; end if; return Duplicate_Subexpr (Assoc); end if; Next_Discriminant (Parent_Disc); if No (Assoc_Elmt) then Next (Assoc); else Next_Elmt (Assoc_Elmt); if Present (Assoc_Elmt) then Assoc := Node (Assoc_Elmt); else Assoc := Empty; end if; end if; end loop; end if; Current_Typ := Parent_Typ; Parent_Typ := Etype (Current_Typ); end loop; -- In some cases there's no ancestor value to locate (such as -- when an ancestor part given by an expression defines the -- discriminant value). return Empty; end Ancestor_Discriminant_Value; ---------------------------------- -- Check_Ancestor_Discriminants -- ---------------------------------- procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is Discr : Entity_Id; Disc_Value : Node_Id; Cond : Node_Id; begin Discr := First_Discriminant (Base_Type (Anc_Typ)); while Present (Discr) loop Disc_Value := Ancestor_Discriminant_Value (Discr); if Present (Disc_Value) then Cond := Make_Op_Ne (Loc, Left_Opnd => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Occurrence_Of (Discr, Loc)), Right_Opnd => Disc_Value); Append_To (L, Make_Raise_Constraint_Error (Loc, Condition => Cond, Reason => CE_Discriminant_Check_Failed)); end if; Next_Discriminant (Discr); end loop; end Check_Ancestor_Discriminants; --------------------------- -- Compatible_Int_Bounds -- --------------------------- function Compatible_Int_Bounds (Agg_Bounds : Node_Id; Typ_Bounds : Node_Id) return Boolean is Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds)); Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds)); Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds)); Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds)); begin return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi; end Compatible_Int_Bounds; -------------------------------- -- Get_Constraint_Association -- -------------------------------- function Get_Constraint_Association (T : Entity_Id) return Node_Id is Indic : Node_Id; Typ : Entity_Id; begin Typ := T; -- Handle private types in instances if In_Instance and then Is_Private_Type (Typ) and then Present (Full_View (Typ)) then Typ := Full_View (Typ); end if; Indic := Subtype_Indication (Type_Definition (Parent (Typ))); -- ??? Also need to cover case of a type mark denoting a subtype -- with constraint. if Nkind (Indic) = N_Subtype_Indication and then Present (Constraint (Indic)) then return First (Constraints (Constraint (Indic))); end if; return Empty; end Get_Constraint_Association; ------------------------------- -- Init_Hidden_Discriminants -- ------------------------------- procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is Btype : Entity_Id; Parent_Type : Entity_Id; Disc : Entity_Id; Discr_Val : Elmt_Id; begin Btype := Base_Type (Typ); while Is_Derived_Type (Btype) and then Present (Stored_Constraint (Btype)) loop Parent_Type := Etype (Btype); Disc := First_Discriminant (Parent_Type); Discr_Val := First_Elmt (Stored_Constraint (Base_Type (Typ))); while Present (Discr_Val) loop -- Only those discriminants of the parent that are not -- renamed by discriminants of the derived type need to -- be added explicitly. if not Is_Entity_Name (Node (Discr_Val)) or else Ekind (Entity (Node (Discr_Val))) /= E_Discriminant then Comp_Expr := Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Occurrence_Of (Disc, Loc)); Instr := Make_OK_Assignment_Statement (Loc, Name => Comp_Expr, Expression => New_Copy_Tree (Node (Discr_Val))); Set_No_Ctrl_Actions (Instr); Append_To (List, Instr); end if; Next_Discriminant (Disc); Next_Elmt (Discr_Val); end loop; Btype := Base_Type (Parent_Type); end loop; end Init_Hidden_Discriminants; ------------------------- -- Is_Int_Range_Bounds -- ------------------------- function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is begin return Nkind (Bounds) = N_Range and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal and then Nkind (High_Bound (Bounds)) = N_Integer_Literal; end Is_Int_Range_Bounds; ----------------------------------- -- Generate_Finalization_Actions -- ----------------------------------- procedure Generate_Finalization_Actions is begin -- Do the work only the first time this is called if Finalization_Done then return; end if; Finalization_Done := True; -- Determine the external finalization list. It is either the -- finalization list of the outer-scope or the one coming from -- an outer aggregate. When the target is not a temporary, the -- proper scope is the scope of the target rather than the -- potentially transient current scope. if Is_Controlled (Typ) and then Ancestor_Is_Subtype_Mark then Ref := Convert_To (Init_Typ, New_Copy_Tree (Target)); Set_Assignment_OK (Ref); Append_To (L, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Find_Prim_Op (Init_Typ, Name_Initialize), Loc), Parameter_Associations => New_List (New_Copy_Tree (Ref)))); end if; end Generate_Finalization_Actions; function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result; -- If default expression of a component mentions a discriminant of the -- type, it must be rewritten as the discriminant of the target object. function Replace_Type (Expr : Node_Id) return Traverse_Result; -- If the aggregate contains a self-reference, traverse each expression -- to replace a possible self-reference with a reference to the proper -- component of the target of the assignment. -------------------------- -- Rewrite_Discriminant -- -------------------------- function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is begin if Is_Entity_Name (Expr) and then Present (Entity (Expr)) and then Ekind (Entity (Expr)) = E_In_Parameter and then Present (Discriminal_Link (Entity (Expr))) and then Scope (Discriminal_Link (Entity (Expr))) = Base_Type (Etype (N)) then Rewrite (Expr, Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Lhs), Selector_Name => Make_Identifier (Loc, Chars (Expr)))); end if; return OK; end Rewrite_Discriminant; ------------------ -- Replace_Type -- ------------------ function Replace_Type (Expr : Node_Id) return Traverse_Result is begin -- Note regarding the Root_Type test below: Aggregate components for -- self-referential types include attribute references to the current -- instance, of the form: Typ'access, etc.. These references are -- rewritten as references to the target of the aggregate: the -- left-hand side of an assignment, the entity in a declaration, -- or a temporary. Without this test, we would improperly extended -- this rewriting to attribute references whose prefix was not the -- type of the aggregate. if Nkind (Expr) = N_Attribute_Reference and then Is_Entity_Name (Prefix (Expr)) and then Is_Type (Entity (Prefix (Expr))) and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr))) then if Is_Entity_Name (Lhs) then Rewrite (Prefix (Expr), New_Occurrence_Of (Entity (Lhs), Loc)); elsif Nkind (Lhs) = N_Selected_Component then Rewrite (Expr, Make_Attribute_Reference (Loc, Attribute_Name => Name_Unrestricted_Access, Prefix => New_Copy_Tree (Lhs))); Set_Analyzed (Parent (Expr), False); else Rewrite (Expr, Make_Attribute_Reference (Loc, Attribute_Name => Name_Unrestricted_Access, Prefix => New_Copy_Tree (Lhs))); Set_Analyzed (Parent (Expr), False); end if; end if; return OK; end Replace_Type; procedure Replace_Self_Reference is new Traverse_Proc (Replace_Type); procedure Replace_Discriminants is new Traverse_Proc (Rewrite_Discriminant); -- Start of processing for Build_Record_Aggr_Code begin if Has_Self_Reference (N) then Replace_Self_Reference (N); end if; -- If the target of the aggregate is class-wide, we must convert it -- to the actual type of the aggregate, so that the proper components -- are visible. We know already that the types are compatible. if Present (Etype (Lhs)) and then Is_Class_Wide_Type (Etype (Lhs)) then Target := Unchecked_Convert_To (Typ, Lhs); else Target := Lhs; end if; -- Deal with the ancestor part of extension aggregates or with the -- discriminants of the root type. if Nkind (N) = N_Extension_Aggregate then declare Ancestor : constant Node_Id := Ancestor_Part (N); Assign : List_Id; begin -- If the ancestor part is a subtype mark "T", we generate -- init-proc (T (tmp)); if T is constrained and -- init-proc (S (tmp)); where S applies an appropriate -- constraint if T is unconstrained if Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor)) then Ancestor_Is_Subtype_Mark := True; if Is_Constrained (Entity (Ancestor)) then Init_Typ := Entity (Ancestor); -- For an ancestor part given by an unconstrained type mark, -- create a subtype constrained by appropriate corresponding -- discriminant values coming from either associations of the -- aggregate or a constraint on a parent type. The subtype will -- be used to generate the correct default value for the -- ancestor part. elsif Has_Discriminants (Entity (Ancestor)) then declare Anc_Typ : constant Entity_Id := Entity (Ancestor); Anc_Constr : constant List_Id := New_List; Discrim : Entity_Id; Disc_Value : Node_Id; New_Indic : Node_Id; Subt_Decl : Node_Id; begin Discrim := First_Discriminant (Anc_Typ); while Present (Discrim) loop Disc_Value := Ancestor_Discriminant_Value (Discrim); Append_To (Anc_Constr, Disc_Value); Next_Discriminant (Discrim); end loop; New_Indic := Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => Anc_Constr)); Init_Typ := Create_Itype (Ekind (Anc_Typ), N); Subt_Decl := Make_Subtype_Declaration (Loc, Defining_Identifier => Init_Typ, Subtype_Indication => New_Indic); -- Itypes must be analyzed with checks off Declaration -- must have a parent for proper handling of subsidiary -- actions. Set_Parent (Subt_Decl, N); Analyze (Subt_Decl, Suppress => All_Checks); end; end if; Ref := Convert_To (Init_Typ, New_Copy_Tree (Target)); Set_Assignment_OK (Ref); if not Is_Interface (Init_Typ) then Append_List_To (L, Build_Initialization_Call (Loc, Id_Ref => Ref, Typ => Init_Typ, In_Init_Proc => Within_Init_Proc, With_Default_Init => Has_Default_Init_Comps (N) or else Has_Task (Base_Type (Init_Typ)))); if Is_Constrained (Entity (Ancestor)) and then Has_Discriminants (Entity (Ancestor)) then Check_Ancestor_Discriminants (Entity (Ancestor)); end if; end if; -- Handle calls to C++ constructors elsif Is_CPP_Constructor_Call (Ancestor) then Init_Typ := Etype (Ancestor); Ref := Convert_To (Init_Typ, New_Copy_Tree (Target)); Set_Assignment_OK (Ref); Append_List_To (L, Build_Initialization_Call (Loc, Id_Ref => Ref, Typ => Init_Typ, In_Init_Proc => Within_Init_Proc, With_Default_Init => Has_Default_Init_Comps (N), Constructor_Ref => Ancestor)); -- Ada 2005 (AI-287): If the ancestor part is an aggregate of -- limited type, a recursive call expands the ancestor. Note that -- in the limited case, the ancestor part must be either a -- function call (possibly qualified, or wrapped in an unchecked -- conversion) or aggregate (definitely qualified). -- The ancestor part can also be a function call (that may be -- transformed into an explicit dereference) or a qualification -- of one such. elsif Is_Limited_Type (Etype (Ancestor)) and then Nkind_In (Unqualify (Ancestor), N_Aggregate, N_Extension_Aggregate) then Ancestor_Is_Expression := True; -- Set up finalization data for enclosing record, because -- controlled subcomponents of the ancestor part will be -- attached to it. Generate_Finalization_Actions; Append_List_To (L, Build_Record_Aggr_Code (N => Unqualify (Ancestor), Typ => Etype (Unqualify (Ancestor)), Lhs => Target)); -- If the ancestor part is an expression "E", we generate -- T (tmp) := E; -- In Ada 2005, this includes the case of a (possibly qualified) -- limited function call. The assignment will turn into a -- build-in-place function call (for further details, see -- Make_Build_In_Place_Call_In_Assignment). else Ancestor_Is_Expression := True; Init_Typ := Etype (Ancestor); -- If the ancestor part is an aggregate, force its full -- expansion, which was delayed. if Nkind_In (Unqualify (Ancestor), N_Aggregate, N_Extension_Aggregate) then Set_Analyzed (Ancestor, False); Set_Analyzed (Expression (Ancestor), False); end if; Ref := Convert_To (Init_Typ, New_Copy_Tree (Target)); Set_Assignment_OK (Ref); -- Make the assignment without usual controlled actions since -- we only want the post adjust but not the pre finalize here -- Add manual adjust when necessary. Assign := New_List ( Make_OK_Assignment_Statement (Loc, Name => Ref, Expression => Ancestor)); Set_No_Ctrl_Actions (First (Assign)); -- Assign the tag now to make sure that the dispatching call in -- the subsequent deep_adjust works properly (unless VM_Target, -- where tags are implicit). if Tagged_Type_Expansion then Instr := Make_OK_Assignment_Statement (Loc, Name => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Reference_To (First_Tag_Component (Base_Type (Typ)), Loc)), Expression => Unchecked_Convert_To (RTE (RE_Tag), New_Reference_To (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))), Loc))); Set_Assignment_OK (Name (Instr)); Append_To (Assign, Instr); -- Ada 2005 (AI-251): If tagged type has progenitors we must -- also initialize tags of the secondary dispatch tables. if Has_Interfaces (Base_Type (Typ)) then Init_Secondary_Tags (Typ => Base_Type (Typ), Target => Target, Stmts_List => Assign); end if; end if; -- Call Adjust manually if Needs_Finalization (Etype (Ancestor)) and then not Is_Limited_Type (Etype (Ancestor)) then Append_To (Assign, Make_Adjust_Call ( Obj_Ref => New_Copy_Tree (Ref), Typ => Etype (Ancestor))); end if; Append_To (L, Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign)); if Has_Discriminants (Init_Typ) then Check_Ancestor_Discriminants (Init_Typ); end if; end if; end; -- Generate assignments of hidden assignments. If the base type is an -- unchecked union, the discriminants are unknown to the back-end and -- absent from a value of the type, so assignments for them are not -- emitted. if Has_Discriminants (Typ) and then not Is_Unchecked_Union (Base_Type (Typ)) then Init_Hidden_Discriminants (Typ, L); end if; -- Normal case (not an extension aggregate) else -- Generate the discriminant expressions, component by component. -- If the base type is an unchecked union, the discriminants are -- unknown to the back-end and absent from a value of the type, so -- assignments for them are not emitted. if Has_Discriminants (Typ) and then not Is_Unchecked_Union (Base_Type (Typ)) then Init_Hidden_Discriminants (Typ, L); -- Generate discriminant init values for the visible discriminants declare Discriminant : Entity_Id; Discriminant_Value : Node_Id; begin Discriminant := First_Stored_Discriminant (Typ); while Present (Discriminant) loop Comp_Expr := Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Occurrence_Of (Discriminant, Loc)); Discriminant_Value := Get_Discriminant_Value ( Discriminant, N_Typ, Discriminant_Constraint (N_Typ)); Instr := Make_OK_Assignment_Statement (Loc, Name => Comp_Expr, Expression => New_Copy_Tree (Discriminant_Value)); Set_No_Ctrl_Actions (Instr); Append_To (L, Instr); Next_Stored_Discriminant (Discriminant); end loop; end; end if; end if; -- For CPP types we generate an implicit call to the C++ default -- constructor to ensure the proper initialization of the _Tag -- component. if Is_CPP_Class (Root_Type (Typ)) and then CPP_Num_Prims (Typ) > 0 then Invoke_Constructor : declare CPP_Parent : constant Entity_Id := Enclosing_CPP_Parent (Typ); procedure Invoke_IC_Proc (T : Entity_Id); -- Recursive routine used to climb to parents. Required because -- parents must be initialized before descendants to ensure -- propagation of inherited C++ slots. -------------------- -- Invoke_IC_Proc -- -------------------- procedure Invoke_IC_Proc (T : Entity_Id) is begin -- Avoid generating extra calls. Initialization required -- only for types defined from the level of derivation of -- type of the constructor and the type of the aggregate. if T = CPP_Parent then return; end if; Invoke_IC_Proc (Etype (T)); -- Generate call to the IC routine if Present (CPP_Init_Proc (T)) then Append_To (L, Make_Procedure_Call_Statement (Loc, New_Reference_To (CPP_Init_Proc (T), Loc))); end if; end Invoke_IC_Proc; -- Start of processing for Invoke_Constructor begin -- Implicit invocation of the C++ constructor if Nkind (N) = N_Aggregate then Append_To (L, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Base_Init_Proc (CPP_Parent), Loc), Parameter_Associations => New_List ( Unchecked_Convert_To (CPP_Parent, New_Copy_Tree (Lhs))))); end if; Invoke_IC_Proc (Typ); end Invoke_Constructor; end if; -- Generate the assignments, component by component -- tmp.comp1 := Expr1_From_Aggr; -- tmp.comp2 := Expr2_From_Aggr; -- .... Comp := First (Component_Associations (N)); while Present (Comp) loop Selector := Entity (First (Choices (Comp))); -- C++ constructors if Is_CPP_Constructor_Call (Expression (Comp)) then Append_List_To (L, Build_Initialization_Call (Loc, Id_Ref => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Occurrence_Of (Selector, Loc)), Typ => Etype (Selector), Enclos_Type => Typ, With_Default_Init => True, Constructor_Ref => Expression (Comp))); -- Ada 2005 (AI-287): For each default-initialized component generate -- a call to the corresponding IP subprogram if available. elsif Box_Present (Comp) and then Has_Non_Null_Base_Init_Proc (Etype (Selector)) then if Ekind (Selector) /= E_Discriminant then Generate_Finalization_Actions; end if; -- Ada 2005 (AI-287): If the component type has tasks then -- generate the activation chain and master entities (except -- in case of an allocator because in that case these entities -- are generated by Build_Task_Allocate_Block_With_Init_Stmts). declare Ctype : constant Entity_Id := Etype (Selector); Inside_Allocator : Boolean := False; P : Node_Id := Parent (N); begin if Is_Task_Type (Ctype) or else Has_Task (Ctype) then while Present (P) loop if Nkind (P) = N_Allocator then Inside_Allocator := True; exit; end if; P := Parent (P); end loop; if not Inside_Init_Proc and not Inside_Allocator then Build_Activation_Chain_Entity (N); end if; end if; end; Append_List_To (L, Build_Initialization_Call (Loc, Id_Ref => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Occurrence_Of (Selector, Loc)), Typ => Etype (Selector), Enclos_Type => Typ, With_Default_Init => True)); -- Prepare for component assignment elsif Ekind (Selector) /= E_Discriminant or else Nkind (N) = N_Extension_Aggregate then -- All the discriminants have now been assigned -- This is now a good moment to initialize and attach all the -- controllers. Their position may depend on the discriminants. if Ekind (Selector) /= E_Discriminant then Generate_Finalization_Actions; end if; Comp_Type := Underlying_Type (Etype (Selector)); Comp_Expr := Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Occurrence_Of (Selector, Loc)); if Nkind (Expression (Comp)) = N_Qualified_Expression then Expr_Q := Expression (Expression (Comp)); else Expr_Q := Expression (Comp); end if; -- Now either create the assignment or generate the code for the -- inner aggregate top-down. if Is_Delayed_Aggregate (Expr_Q) then -- We have the following case of aggregate nesting inside -- an object declaration: -- type Arr_Typ is array (Integer range <>) of ...; -- type Rec_Typ (...) is record -- Obj_Arr_Typ : Arr_Typ (A .. B); -- end record; -- Obj_Rec_Typ : Rec_Typ := (..., -- Obj_Arr_Typ => (X => (...), Y => (...))); -- The length of the ranges of the aggregate and Obj_Add_Typ -- are equal (B - A = Y - X), but they do not coincide (X /= -- A and B /= Y). This case requires array sliding which is -- performed in the following manner: -- subtype Arr_Sub is Arr_Typ (X .. Y); -- Temp : Arr_Sub; -- Temp (X) := (...); -- ... -- Temp (Y) := (...); -- Obj_Rec_Typ.Obj_Arr_Typ := Temp; if Ekind (Comp_Type) = E_Array_Subtype and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q)) and then Is_Int_Range_Bounds (First_Index (Comp_Type)) and then not Compatible_Int_Bounds (Agg_Bounds => Aggregate_Bounds (Expr_Q), Typ_Bounds => First_Index (Comp_Type)) then -- Create the array subtype with bounds equal to those of -- the corresponding aggregate. declare SubE : constant Entity_Id := Make_Temporary (Loc, 'T'); SubD : constant Node_Id := Make_Subtype_Declaration (Loc, Defining_Identifier => SubE, Subtype_Indication => Make_Subtype_Indication (Loc, Subtype_Mark => New_Reference_To (Etype (Comp_Type), Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints => New_List ( New_Copy_Tree (Aggregate_Bounds (Expr_Q)))))); -- Create a temporary array of the above subtype which -- will be used to capture the aggregate assignments. TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N); TmpD : constant Node_Id := Make_Object_Declaration (Loc, Defining_Identifier => TmpE, Object_Definition => New_Reference_To (SubE, Loc)); begin Set_No_Initialization (TmpD); Append_To (L, SubD); Append_To (L, TmpD); -- Expand aggregate into assignments to the temp array Append_List_To (L, Late_Expansion (Expr_Q, Comp_Type, New_Reference_To (TmpE, Loc))); -- Slide Append_To (L, Make_Assignment_Statement (Loc, Name => New_Copy_Tree (Comp_Expr), Expression => New_Reference_To (TmpE, Loc))); end; -- Normal case (sliding not required) else Append_List_To (L, Late_Expansion (Expr_Q, Comp_Type, Comp_Expr)); end if; -- Expr_Q is not delayed aggregate else if Has_Discriminants (Typ) then Replace_Discriminants (Expr_Q); end if; Instr := Make_OK_Assignment_Statement (Loc, Name => Comp_Expr, Expression => Expr_Q); Set_No_Ctrl_Actions (Instr); Append_To (L, Instr); -- Adjust the tag if tagged (because of possible view -- conversions), unless compiling for a VM where tags are -- implicit. -- tmp.comp._tag := comp_typ'tag; if Is_Tagged_Type (Comp_Type) and then Tagged_Type_Expansion then Instr := Make_OK_Assignment_Statement (Loc, Name => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Comp_Expr), Selector_Name => New_Reference_To (First_Tag_Component (Comp_Type), Loc)), Expression => Unchecked_Convert_To (RTE (RE_Tag), New_Reference_To (Node (First_Elmt (Access_Disp_Table (Comp_Type))), Loc))); Append_To (L, Instr); end if; -- Generate: -- Adjust (tmp.comp); if Needs_Finalization (Comp_Type) and then not Is_Limited_Type (Comp_Type) then Append_To (L, Make_Adjust_Call ( Obj_Ref => New_Copy_Tree (Comp_Expr), Typ => Comp_Type)); end if; end if; -- ??? elsif Ekind (Selector) = E_Discriminant and then Nkind (N) /= N_Extension_Aggregate and then Nkind (Parent (N)) = N_Component_Association and then Is_Constrained (Typ) then -- We must check that the discriminant value imposed by the -- context is the same as the value given in the subaggregate, -- because after the expansion into assignments there is no -- record on which to perform a regular discriminant check. declare D_Val : Elmt_Id; Disc : Entity_Id; begin D_Val := First_Elmt (Discriminant_Constraint (Typ)); Disc := First_Discriminant (Typ); while Chars (Disc) /= Chars (Selector) loop Next_Discriminant (Disc); Next_Elmt (D_Val); end loop; pragma Assert (Present (D_Val)); -- This check cannot performed for components that are -- constrained by a current instance, because this is not a -- value that can be compared with the actual constraint. if Nkind (Node (D_Val)) /= N_Attribute_Reference or else not Is_Entity_Name (Prefix (Node (D_Val))) or else not Is_Type (Entity (Prefix (Node (D_Val)))) then Append_To (L, Make_Raise_Constraint_Error (Loc, Condition => Make_Op_Ne (Loc, Left_Opnd => New_Copy_Tree (Node (D_Val)), Right_Opnd => Expression (Comp)), Reason => CE_Discriminant_Check_Failed)); else -- Find self-reference in previous discriminant assignment, -- and replace with proper expression. declare Ass : Node_Id; begin Ass := First (L); while Present (Ass) loop if Nkind (Ass) = N_Assignment_Statement and then Nkind (Name (Ass)) = N_Selected_Component and then Chars (Selector_Name (Name (Ass))) = Chars (Disc) then Set_Expression (Ass, New_Copy_Tree (Expression (Comp))); exit; end if; Next (Ass); end loop; end; end if; end; end if; Next (Comp); end loop; -- If the type is tagged, the tag needs to be initialized (unless -- compiling for the Java VM where tags are implicit). It is done -- late in the initialization process because in some cases, we call -- the init proc of an ancestor which will not leave out the right tag if Ancestor_Is_Expression then null; -- For CPP types we generated a call to the C++ default constructor -- before the components have been initialized to ensure the proper -- initialization of the _Tag component (see above). elsif Is_CPP_Class (Typ) then null; elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then Instr := Make_OK_Assignment_Statement (Loc, Name => Make_Selected_Component (Loc, Prefix => New_Copy_Tree (Target), Selector_Name => New_Reference_To (First_Tag_Component (Base_Type (Typ)), Loc)), Expression => Unchecked_Convert_To (RTE (RE_Tag), New_Reference_To (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))), Loc))); Append_To (L, Instr); -- Ada 2005 (AI-251): If the tagged type has been derived from -- abstract interfaces we must also initialize the tags of the -- secondary dispatch tables. if Has_Interfaces (Base_Type (Typ)) then Init_Secondary_Tags (Typ => Base_Type (Typ), Target => Target, Stmts_List => L); end if; end if; -- If the controllers have not been initialized yet (by lack of non- -- discriminant components), let's do it now. Generate_Finalization_Actions; return L; end Build_Record_Aggr_Code; ------------------------------- -- Convert_Aggr_In_Allocator -- ------------------------------- procedure Convert_Aggr_In_Allocator (Alloc : Node_Id; Decl : Node_Id; Aggr : Node_Id) is Loc : constant Source_Ptr := Sloc (Aggr); Typ : constant Entity_Id := Etype (Aggr); Temp : constant Entity_Id := Defining_Identifier (Decl); Occ : constant Node_Id := Unchecked_Convert_To (Typ, Make_Explicit_Dereference (Loc, New_Reference_To (Temp, Loc))); begin if Is_Array_Type (Typ) then Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ); elsif Has_Default_Init_Comps (Aggr) then declare L : constant List_Id := New_List; Init_Stmts : List_Id; begin Init_Stmts := Late_Expansion (Aggr, Typ, Occ); if Has_Task (Typ) then Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts); Insert_Actions (Alloc, L); else Insert_Actions (Alloc, Init_Stmts); end if; end; else Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ)); end if; end Convert_Aggr_In_Allocator; -------------------------------- -- Convert_Aggr_In_Assignment -- -------------------------------- procedure Convert_Aggr_In_Assignment (N : Node_Id) is Aggr : Node_Id := Expression (N); Typ : constant Entity_Id := Etype (Aggr); Occ : constant Node_Id := New_Copy_Tree (Name (N)); begin if Nkind (Aggr) = N_Qualified_Expression then Aggr := Expression (Aggr); end if; Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ)); end Convert_Aggr_In_Assignment; --------------------------------- -- Convert_Aggr_In_Object_Decl -- --------------------------------- procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is Obj : constant Entity_Id := Defining_Identifier (N); Aggr : Node_Id := Expression (N); Loc : constant Source_Ptr := Sloc (Aggr); Typ : constant Entity_Id := Etype (Aggr); Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc); function Discriminants_Ok return Boolean; -- If the object type is constrained, the discriminants in the -- aggregate must be checked against the discriminants of the subtype. -- This cannot be done using Apply_Discriminant_Checks because after -- expansion there is no aggregate left to check. ---------------------- -- Discriminants_Ok -- ---------------------- function Discriminants_Ok return Boolean is Cond : Node_Id := Empty; Check : Node_Id; D : Entity_Id; Disc1 : Elmt_Id; Disc2 : Elmt_Id; Val1 : Node_Id; Val2 : Node_Id; begin D := First_Discriminant (Typ); Disc1 := First_Elmt (Discriminant_Constraint (Typ)); Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj))); while Present (Disc1) and then Present (Disc2) loop Val1 := Node (Disc1); Val2 := Node (Disc2); if not Is_OK_Static_Expression (Val1) or else not Is_OK_Static_Expression (Val2) then Check := Make_Op_Ne (Loc, Left_Opnd => Duplicate_Subexpr (Val1), Right_Opnd => Duplicate_Subexpr (Val2)); if No (Cond) then Cond := Check; else Cond := Make_Or_Else (Loc, Left_Opnd => Cond, Right_Opnd => Check); end if; elsif Expr_Value (Val1) /= Expr_Value (Val2) then Apply_Compile_Time_Constraint_Error (Aggr, Msg => "incorrect value for discriminant&?", Reason => CE_Discriminant_Check_Failed, Ent => D); return False; end if; Next_Discriminant (D); Next_Elmt (Disc1); Next_Elmt (Disc2); end loop; -- If any discriminant constraint is non-static, emit a check if Present (Cond) then Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Cond, Reason => CE_Discriminant_Check_Failed)); end if; return True; end Discriminants_Ok; -- Start of processing for Convert_Aggr_In_Object_Decl begin Set_Assignment_OK (Occ); if Nkind (Aggr) = N_Qualified_Expression then Aggr := Expression (Aggr); end if; if Has_Discriminants (Typ) and then Typ /= Etype (Obj) and then Is_Constrained (Etype (Obj)) and then not Discriminants_Ok then return; end if; -- If the context is an extended return statement, it has its own -- finalization machinery (i.e. works like a transient scope) and -- we do not want to create an additional one, because objects on -- the finalization list of the return must be moved to the caller's -- finalization list to complete the return. -- However, if the aggregate is limited, it is built in place, and the -- controlled components are not assigned to intermediate temporaries -- so there is no need for a transient scope in this case either. if Requires_Transient_Scope (Typ) and then Ekind (Current_Scope) /= E_Return_Statement and then not Is_Limited_Type (Typ) then Establish_Transient_Scope (Aggr, Sec_Stack => Is_Controlled (Typ) or else Has_Controlled_Component (Typ)); end if; Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ)); Set_No_Initialization (N); Initialize_Discriminants (N, Typ); end Convert_Aggr_In_Object_Decl; ------------------------------------- -- Convert_Array_Aggr_In_Allocator -- ------------------------------------- procedure Convert_Array_Aggr_In_Allocator (Decl : Node_Id; Aggr : Node_Id; Target : Node_Id) is Aggr_Code : List_Id; Typ : constant Entity_Id := Etype (Aggr); Ctyp : constant Entity_Id := Component_Type (Typ); begin -- The target is an explicit dereference of the allocated object. -- Generate component assignments to it, as for an aggregate that -- appears on the right-hand side of an assignment statement. Aggr_Code := Build_Array_Aggr_Code (Aggr, Ctype => Ctyp, Index => First_Index (Typ), Into => Target, Scalar_Comp => Is_Scalar_Type (Ctyp)); Insert_Actions_After (Decl, Aggr_Code); end Convert_Array_Aggr_In_Allocator; ---------------------------- -- Convert_To_Assignments -- ---------------------------- procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); T : Entity_Id; Temp : Entity_Id; Instr : Node_Id; Target_Expr : Node_Id; Parent_Kind : Node_Kind; Unc_Decl : Boolean := False; Parent_Node : Node_Id; begin pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N)); pragma Assert (Is_Record_Type (Typ)); Parent_Node := Parent (N); Parent_Kind := Nkind (Parent_Node); if Parent_Kind = N_Qualified_Expression then -- Check if we are in a unconstrained declaration because in this -- case the current delayed expansion mechanism doesn't work when -- the declared object size depend on the initializing expr. begin Parent_Node := Parent (Parent_Node); Parent_Kind := Nkind (Parent_Node); if Parent_Kind = N_Object_Declaration then Unc_Decl := not Is_Entity_Name (Object_Definition (Parent_Node)) or else Has_Discriminants (Entity (Object_Definition (Parent_Node))) or else Is_Class_Wide_Type (Entity (Object_Definition (Parent_Node))); end if; end; end if; -- Just set the Delay flag in the cases where the transformation will be -- done top down from above. if False -- Internal aggregate (transformed when expanding the parent) or else Parent_Kind = N_Aggregate or else Parent_Kind = N_Extension_Aggregate or else Parent_Kind = N_Component_Association -- Allocator (see Convert_Aggr_In_Allocator) or else Parent_Kind = N_Allocator -- Object declaration (see Convert_Aggr_In_Object_Decl) or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl) -- Safe assignment (see Convert_Aggr_Assignments). So far only the -- assignments in init procs are taken into account. or else (Parent_Kind = N_Assignment_Statement and then Inside_Init_Proc) -- (Ada 2005) An inherently limited type in a return statement, -- which will be handled in a build-in-place fashion, and may be -- rewritten as an extended return and have its own finalization -- machinery. In the case of a simple return, the aggregate needs -- to be delayed until the scope for the return statement has been -- created, so that any finalization chain will be associated with -- that scope. For extended returns, we delay expansion to avoid the -- creation of an unwanted transient scope that could result in -- premature finalization of the return object (which is built in -- in place within the caller's scope). or else (Is_Immutably_Limited_Type (Typ) and then (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement or else Nkind (Parent_Node) = N_Simple_Return_Statement)) then Set_Expansion_Delayed (N); return; end if; if Requires_Transient_Scope (Typ) then Establish_Transient_Scope (N, Sec_Stack => Is_Controlled (Typ) or else Has_Controlled_Component (Typ)); end if; -- If the aggregate is non-limited, create a temporary. If it is limited -- and the context is an assignment, this is a subaggregate for an -- enclosing aggregate being expanded. It must be built in place, so use -- the target of the current assignment. if Is_Limited_Type (Typ) and then Nkind (Parent (N)) = N_Assignment_Statement then Target_Expr := New_Copy_Tree (Name (Parent (N))); Insert_Actions (Parent (N), Build_Record_Aggr_Code (N, Typ, Target_Expr)); Rewrite (Parent (N), Make_Null_Statement (Loc)); else Temp := Make_Temporary (Loc, 'A', N); -- If the type inherits unknown discriminants, use the view with -- known discriminants if available. if Has_Unknown_Discriminants (Typ) and then Present (Underlying_Record_View (Typ)) then T := Underlying_Record_View (Typ); else T := Typ; end if; Instr := Make_Object_Declaration (Loc, Defining_Identifier => Temp, Object_Definition => New_Occurrence_Of (T, Loc)); Set_No_Initialization (Instr); Insert_Action (N, Instr); Initialize_Discriminants (Instr, T); Target_Expr := New_Occurrence_Of (Temp, Loc); Insert_Actions (N, Build_Record_Aggr_Code (N, T, Target_Expr)); Rewrite (N, New_Occurrence_Of (Temp, Loc)); Analyze_And_Resolve (N, T); end if; end Convert_To_Assignments; --------------------------- -- Convert_To_Positional -- --------------------------- procedure Convert_To_Positional (N : Node_Id; Max_Others_Replicate : Nat := 5; Handle_Bit_Packed : Boolean := False) is Typ : constant Entity_Id := Etype (N); Static_Components : Boolean := True; procedure Check_Static_Components; -- Check whether all components of the aggregate are compile-time known -- values, and can be passed as is to the back-end without further -- expansion. function Flatten (N : Node_Id; Ix : Node_Id; Ixb : Node_Id) return Boolean; -- Convert the aggregate into a purely positional form if possible. On -- entry the bounds of all dimensions are known to be static, and the -- total number of components is safe enough to expand. function Is_Flat (N : Node_Id; Dims : Int) return Boolean; -- Return True iff the array N is flat (which is not trivial in the case -- of multidimensional aggregates). ----------------------------- -- Check_Static_Components -- ----------------------------- procedure Check_Static_Components is Expr : Node_Id; begin Static_Components := True; if Nkind (N) = N_String_Literal then null; elsif Present (Expressions (N)) then Expr := First (Expressions (N)); while Present (Expr) loop if Nkind (Expr) /= N_Aggregate or else not Compile_Time_Known_Aggregate (Expr) or else Expansion_Delayed (Expr) then Static_Components := False; exit; end if; Next (Expr); end loop; end if; if Nkind (N) = N_Aggregate and then Present (Component_Associations (N)) then Expr := First (Component_Associations (N)); while Present (Expr) loop if Nkind_In (Expression (Expr), N_Integer_Literal, N_Real_Literal) then null; elsif Is_Entity_Name (Expression (Expr)) and then Present (Entity (Expression (Expr))) and then Ekind (Entity (Expression (Expr))) = E_Enumeration_Literal then null; elsif Nkind (Expression (Expr)) /= N_Aggregate or else not Compile_Time_Known_Aggregate (Expression (Expr)) or else Expansion_Delayed (Expression (Expr)) then Static_Components := False; exit; end if; Next (Expr); end loop; end if; end Check_Static_Components; ------------- -- Flatten -- ------------- function Flatten (N : Node_Id; Ix : Node_Id; Ixb : Node_Id) return Boolean is Loc : constant Source_Ptr := Sloc (N); Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb)); Lo : constant Node_Id := Type_Low_Bound (Etype (Ix)); Hi : constant Node_Id := Type_High_Bound (Etype (Ix)); Lov : Uint; Hiv : Uint; Others_Present : Boolean := False; begin if Nkind (Original_Node (N)) = N_String_Literal then return True; end if; if not Compile_Time_Known_Value (Lo) or else not Compile_Time_Known_Value (Hi) then return False; end if; Lov := Expr_Value (Lo); Hiv := Expr_Value (Hi); -- Check if there is an others choice if Present (Component_Associations (N)) then declare Assoc : Node_Id; Choice : Node_Id; begin Assoc := First (Component_Associations (N)); while Present (Assoc) loop -- If this is a box association, flattening is in general -- not possible because at this point we cannot tell if the -- default is static or even exists. if Box_Present (Assoc) then return False; end if; Choice := First (Choices (Assoc)); while Present (Choice) loop if Nkind (Choice) = N_Others_Choice then Others_Present := True; end if; Next (Choice); end loop; Next (Assoc); end loop; end; end if; -- If the low bound is not known at compile time and others is not -- present we can proceed since the bounds can be obtained from the -- aggregate. -- Note: This case is required in VM platforms since their backends -- normalize array indexes in the range 0 .. N-1. Hence, if we do -- not flat an array whose bounds cannot be obtained from the type -- of the index the backend has no way to properly generate the code. -- See ACATS c460010 for an example. if Hiv < Lov or else (not Compile_Time_Known_Value (Blo) and then Others_Present) then return False; end if; -- Determine if set of alternatives is suitable for conversion and -- build an array containing the values in sequence. declare Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv)) of Node_Id := (others => Empty); -- The values in the aggregate sorted appropriately Vlist : List_Id; -- Same data as Vals in list form Rep_Count : Nat; -- Used to validate Max_Others_Replicate limit Elmt : Node_Id; Num : Int := UI_To_Int (Lov); Choice_Index : Int; Choice : Node_Id; Lo, Hi : Node_Id; begin if Present (Expressions (N)) then Elmt := First (Expressions (N)); while Present (Elmt) loop if Nkind (Elmt) = N_Aggregate and then Present (Next_Index (Ix)) and then not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb)) then return False; end if; Vals (Num) := Relocate_Node (Elmt); Num := Num + 1; Next (Elmt); end loop; end if; if No (Component_Associations (N)) then return True; end if; Elmt := First (Component_Associations (N)); if Nkind (Expression (Elmt)) = N_Aggregate then if Present (Next_Index (Ix)) and then not Flatten (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb)) then return False; end if; end if; Component_Loop : while Present (Elmt) loop Choice := First (Choices (Elmt)); Choice_Loop : while Present (Choice) loop -- If we have an others choice, fill in the missing elements -- subject to the limit established by Max_Others_Replicate. if Nkind (Choice) = N_Others_Choice then Rep_Count := 0; for J in Vals'Range loop if No (Vals (J)) then Vals (J) := New_Copy_Tree (Expression (Elmt)); Rep_Count := Rep_Count + 1; -- Check for maximum others replication. Note that -- we skip this test if either of the restrictions -- No_Elaboration_Code or No_Implicit_Loops is -- active, if this is a preelaborable unit or a -- predefined unit. This ensures that predefined -- units get the same level of constant folding in -- Ada 95 and Ada 2005, where their categorization -- has changed. declare P : constant Entity_Id := Cunit_Entity (Current_Sem_Unit); begin -- Check if duplication OK and if so continue -- processing. if Restriction_Active (No_Elaboration_Code) or else Restriction_Active (No_Implicit_Loops) or else Is_Preelaborated (P) or else (Ekind (P) = E_Package_Body and then Is_Preelaborated (Spec_Entity (P))) or else Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (P))) then null; -- If duplication not OK, then we return False -- if the replication count is too high elsif Rep_Count > Max_Others_Replicate then return False; -- Continue on if duplication not OK, but the -- replication count is not excessive. else null; end if; end; end if; end loop; exit Component_Loop; -- Case of a subtype mark, identifier or expanded name elsif Is_Entity_Name (Choice) and then Is_Type (Entity (Choice)) then Lo := Type_Low_Bound (Etype (Choice)); Hi := Type_High_Bound (Etype (Choice)); -- Case of subtype indication elsif Nkind (Choice) = N_Subtype_Indication then Lo := Low_Bound (Range_Expression (Constraint (Choice))); Hi := High_Bound (Range_Expression (Constraint (Choice))); -- Case of a range elsif Nkind (Choice) = N_Range then Lo := Low_Bound (Choice); Hi := High_Bound (Choice); -- Normal subexpression case else pragma Assert (Nkind (Choice) in N_Subexpr); if not Compile_Time_Known_Value (Choice) then return False; else Choice_Index := UI_To_Int (Expr_Value (Choice)); if Choice_Index in Vals'Range then Vals (Choice_Index) := New_Copy_Tree (Expression (Elmt)); goto Continue; else -- Choice is statically out-of-range, will be -- rewritten to raise Constraint_Error. return False; end if; end if; end if; -- Range cases merge with Lo,Hi set if not Compile_Time_Known_Value (Lo) or else not Compile_Time_Known_Value (Hi) then return False; else for J in UI_To_Int (Expr_Value (Lo)) .. UI_To_Int (Expr_Value (Hi)) loop Vals (J) := New_Copy_Tree (Expression (Elmt)); end loop; end if; <<Continue>> Next (Choice); end loop Choice_Loop; Next (Elmt); end loop Component_Loop; -- If we get here the conversion is possible Vlist := New_List; for J in Vals'Range loop Append (Vals (J), Vlist); end loop; Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist)); Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N))); return True; end; end Flatten; ------------- -- Is_Flat -- ------------- function Is_Flat (N : Node_Id; Dims : Int) return Boolean is Elmt : Node_Id; begin if Dims = 0 then return True; elsif Nkind (N) = N_Aggregate then if Present (Component_Associations (N)) then return False; else Elmt := First (Expressions (N)); while Present (Elmt) loop if not Is_Flat (Elmt, Dims - 1) then return False; end if; Next (Elmt); end loop; return True; end if; else return True; end if; end Is_Flat; -- Start of processing for Convert_To_Positional begin -- Ada 2005 (AI-287): Do not convert in case of default initialized -- components because in this case will need to call the corresponding -- IP procedure. if Has_Default_Init_Comps (N) then return; end if; if Is_Flat (N, Number_Dimensions (Typ)) then return; end if; if Is_Bit_Packed_Array (Typ) and then not Handle_Bit_Packed then return; end if; -- Do not convert to positional if controlled components are involved -- since these require special processing if Has_Controlled_Component (Typ) then return; end if; Check_Static_Components; -- If the size is known, or all the components are static, try to -- build a fully positional aggregate. -- The size of the type may not be known for an aggregate with -- discriminated array components, but if the components are static -- it is still possible to verify statically that the length is -- compatible with the upper bound of the type, and therefore it is -- worth flattening such aggregates as well. -- For now the back-end expands these aggregates into individual -- assignments to the target anyway, but it is conceivable that -- it will eventually be able to treat such aggregates statically??? if Aggr_Size_OK (N, Typ) and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ))) then if Static_Components then Set_Compile_Time_Known_Aggregate (N); Set_Expansion_Delayed (N, False); end if; Analyze_And_Resolve (N, Typ); end if; end Convert_To_Positional; ---------------------------- -- Expand_Array_Aggregate -- ---------------------------- -- Array aggregate expansion proceeds as follows: -- 1. If requested we generate code to perform all the array aggregate -- bound checks, specifically -- (a) Check that the index range defined by aggregate bounds is -- compatible with corresponding index subtype. -- (b) If an others choice is present check that no aggregate -- index is outside the bounds of the index constraint. -- (c) For multidimensional arrays make sure that all subaggregates -- corresponding to the same dimension have the same bounds. -- 2. Check for packed array aggregate which can be converted to a -- constant so that the aggregate disappeares completely. -- 3. Check case of nested aggregate. Generally nested aggregates are -- handled during the processing of the parent aggregate. -- 4. Check if the aggregate can be statically processed. If this is the -- case pass it as is to Gigi. Note that a necessary condition for -- static processing is that the aggregate be fully positional. -- 5. If in place aggregate expansion is possible (i.e. no need to create -- a temporary) then mark the aggregate as such and return. Otherwise -- create a new temporary and generate the appropriate initialization -- code. procedure Expand_Array_Aggregate (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Ctyp : constant Entity_Id := Component_Type (Typ); -- Typ is the correct constrained array subtype of the aggregate -- Ctyp is the corresponding component type. Aggr_Dimension : constant Pos := Number_Dimensions (Typ); -- Number of aggregate index dimensions Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id; Aggr_High : array (1 .. Aggr_Dimension) of Node_Id; -- Low and High bounds of the constraint for each aggregate index Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id; -- The type of each index Maybe_In_Place_OK : Boolean; -- If the type is neither controlled nor packed and the aggregate -- is the expression in an assignment, assignment in place may be -- possible, provided other conditions are met on the LHS. Others_Present : array (1 .. Aggr_Dimension) of Boolean := (others => False); -- If Others_Present (J) is True, then there is an others choice -- in one of the sub-aggregates of N at dimension J. procedure Build_Constrained_Type (Positional : Boolean); -- If the subtype is not static or unconstrained, build a constrained -- type using the computable sizes of the aggregate and its sub- -- aggregates. procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id); -- Checks that the bounds of Aggr_Bounds are within the bounds defined -- by Index_Bounds. procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos); -- Checks that in a multi-dimensional array aggregate all subaggregates -- corresponding to the same dimension have the same bounds. -- Sub_Aggr is an array sub-aggregate. Dim is the dimension -- corresponding to the sub-aggregate. procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos); -- Computes the values of array Others_Present. Sub_Aggr is the -- array sub-aggregate we start the computation from. Dim is the -- dimension corresponding to the sub-aggregate. function In_Place_Assign_OK return Boolean; -- Simple predicate to determine whether an aggregate assignment can -- be done in place, because none of the new values can depend on the -- components of the target of the assignment. procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos); -- Checks that if an others choice is present in any sub-aggregate no -- aggregate index is outside the bounds of the index constraint. -- Sub_Aggr is an array sub-aggregate. Dim is the dimension -- corresponding to the sub-aggregate. function Safe_Left_Hand_Side (N : Node_Id) return Boolean; -- In addition to Maybe_In_Place_OK, in order for an aggregate to be -- built directly into the target of the assignment it must be free -- of side-effects. ---------------------------- -- Build_Constrained_Type -- ---------------------------- procedure Build_Constrained_Type (Positional : Boolean) is Loc : constant Source_Ptr := Sloc (N); Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A'); Comp : Node_Id; Decl : Node_Id; Typ : constant Entity_Id := Etype (N); Indexes : constant List_Id := New_List; Num : Int; Sub_Agg : Node_Id; begin -- If the aggregate is purely positional, all its subaggregates -- have the same size. We collect the dimensions from the first -- subaggregate at each level. if Positional then Sub_Agg := N; for D in 1 .. Number_Dimensions (Typ) loop Sub_Agg := First (Expressions (Sub_Agg)); Comp := Sub_Agg; Num := 0; while Present (Comp) loop Num := Num + 1; Next (Comp); end loop; Append_To (Indexes, Make_Range (Loc, Low_Bound => Make_Integer_Literal (Loc, 1), High_Bound => Make_Integer_Literal (Loc, Num))); end loop; else -- We know the aggregate type is unconstrained and the aggregate -- is not processable by the back end, therefore not necessarily -- positional. Retrieve each dimension bounds (computed earlier). for D in 1 .. Number_Dimensions (Typ) loop Append ( Make_Range (Loc, Low_Bound => Aggr_Low (D), High_Bound => Aggr_High (D)), Indexes); end loop; end if; Decl := Make_Full_Type_Declaration (Loc, Defining_Identifier => Agg_Type, Type_Definition => Make_Constrained_Array_Definition (Loc, Discrete_Subtype_Definitions => Indexes, Component_Definition => Make_Component_Definition (Loc, Aliased_Present => False, Subtype_Indication => New_Occurrence_Of (Component_Type (Typ), Loc)))); Insert_Action (N, Decl); Analyze (Decl); Set_Etype (N, Agg_Type); Set_Is_Itype (Agg_Type); Freeze_Itype (Agg_Type, N); end Build_Constrained_Type; ------------------ -- Check_Bounds -- ------------------ procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is Aggr_Lo : Node_Id; Aggr_Hi : Node_Id; Ind_Lo : Node_Id; Ind_Hi : Node_Id; Cond : Node_Id := Empty; begin Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi); Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi); -- Generate the following test: -- -- [constraint_error when -- Aggr_Lo <= Aggr_Hi and then -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)] -- As an optimization try to see if some tests are trivially vacuous -- because we are comparing an expression against itself. if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then Cond := Empty; elsif Aggr_Hi = Ind_Hi then Cond := Make_Op_Lt (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo), Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)); elsif Aggr_Lo = Ind_Lo then Cond := Make_Op_Gt (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi), Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi)); else Cond := Make_Or_Else (Loc, Left_Opnd => Make_Op_Lt (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo), Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)), Right_Opnd => Make_Op_Gt (Loc, Left_Opnd => Duplicate_Subexpr (Aggr_Hi), Right_Opnd => Duplicate_Subexpr (Ind_Hi))); end if; if Present (Cond) then Cond := Make_And_Then (Loc, Left_Opnd => Make_Op_Le (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo), Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)), Right_Opnd => Cond); Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False); Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False); Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Cond, Reason => CE_Length_Check_Failed)); end if; end Check_Bounds; ---------------------------- -- Check_Same_Aggr_Bounds -- ---------------------------- procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr)); Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr)); -- The bounds of this specific sub-aggregate Aggr_Lo : constant Node_Id := Aggr_Low (Dim); Aggr_Hi : constant Node_Id := Aggr_High (Dim); -- The bounds of the aggregate for this dimension Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim); -- The index type for this dimension.xxx Cond : Node_Id := Empty; Assoc : Node_Id; Expr : Node_Id; begin -- If index checks are on generate the test -- [constraint_error when -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi] -- As an optimization try to see if some tests are trivially vacuos -- because we are comparing an expression against itself. Also for -- the first dimension the test is trivially vacuous because there -- is just one aggregate for dimension 1. if Index_Checks_Suppressed (Ind_Typ) then Cond := Empty; elsif Dim = 1 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi) then Cond := Empty; elsif Aggr_Hi = Sub_Hi then Cond := Make_Op_Ne (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo), Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)); elsif Aggr_Lo = Sub_Lo then Cond := Make_Op_Ne (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi), Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi)); else Cond := Make_Or_Else (Loc, Left_Opnd => Make_Op_Ne (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo), Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)), Right_Opnd => Make_Op_Ne (Loc, Left_Opnd => Duplicate_Subexpr (Aggr_Hi), Right_Opnd => Duplicate_Subexpr (Sub_Hi))); end if; if Present (Cond) then Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Cond, Reason => CE_Length_Check_Failed)); end if; -- Now look inside the sub-aggregate to see if there is more work if Dim < Aggr_Dimension then -- Process positional components if Present (Expressions (Sub_Aggr)) then Expr := First (Expressions (Sub_Aggr)); while Present (Expr) loop Check_Same_Aggr_Bounds (Expr, Dim + 1); Next (Expr); end loop; end if; -- Process component associations if Present (Component_Associations (Sub_Aggr)) then Assoc := First (Component_Associations (Sub_Aggr)); while Present (Assoc) loop Expr := Expression (Assoc); Check_Same_Aggr_Bounds (Expr, Dim + 1); Next (Assoc); end loop; end if; end if; end Check_Same_Aggr_Bounds; ---------------------------- -- Compute_Others_Present -- ---------------------------- procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is Assoc : Node_Id; Expr : Node_Id; begin if Present (Component_Associations (Sub_Aggr)) then Assoc := Last (Component_Associations (Sub_Aggr)); if Nkind (First (Choices (Assoc))) = N_Others_Choice then Others_Present (Dim) := True; end if; end if; -- Now look inside the sub-aggregate to see if there is more work if Dim < Aggr_Dimension then -- Process positional components if Present (Expressions (Sub_Aggr)) then Expr := First (Expressions (Sub_Aggr)); while Present (Expr) loop Compute_Others_Present (Expr, Dim + 1); Next (Expr); end loop; end if; -- Process component associations if Present (Component_Associations (Sub_Aggr)) then Assoc := First (Component_Associations (Sub_Aggr)); while Present (Assoc) loop Expr := Expression (Assoc); Compute_Others_Present (Expr, Dim + 1); Next (Assoc); end loop; end if; end if; end Compute_Others_Present; ------------------------ -- In_Place_Assign_OK -- ------------------------ function In_Place_Assign_OK return Boolean is Aggr_In : Node_Id; Aggr_Lo : Node_Id; Aggr_Hi : Node_Id; Obj_In : Node_Id; Obj_Lo : Node_Id; Obj_Hi : Node_Id; function Safe_Aggregate (Aggr : Node_Id) return Boolean; -- Check recursively that each component of a (sub)aggregate does -- not depend on the variable being assigned to. function Safe_Component (Expr : Node_Id) return Boolean; -- Verify that an expression cannot depend on the variable being -- assigned to. Room for improvement here (but less than before). -------------------- -- Safe_Aggregate -- -------------------- function Safe_Aggregate (Aggr : Node_Id) return Boolean is Expr : Node_Id; begin if Present (Expressions (Aggr)) then Expr := First (Expressions (Aggr)); while Present (Expr) loop if Nkind (Expr) = N_Aggregate then if not Safe_Aggregate (Expr) then return False; end if; elsif not Safe_Component (Expr) then return False; end if; Next (Expr); end loop; end if; if Present (Component_Associations (Aggr)) then Expr := First (Component_Associations (Aggr)); while Present (Expr) loop if Nkind (Expression (Expr)) = N_Aggregate then if not Safe_Aggregate (Expression (Expr)) then return False; end if; -- If association has a box, no way to determine yet -- whether default can be assigned in place. elsif Box_Present (Expr) then return False; elsif not Safe_Component (Expression (Expr)) then return False; end if; Next (Expr); end loop; end if; return True; end Safe_Aggregate; -------------------- -- Safe_Component -- -------------------- function Safe_Component (Expr : Node_Id) return Boolean is Comp : Node_Id := Expr; function Check_Component (Comp : Node_Id) return Boolean; -- Do the recursive traversal, after copy --------------------- -- Check_Component -- --------------------- function Check_Component (Comp : Node_Id) return Boolean is begin if Is_Overloaded (Comp) then return False; end if; return Compile_Time_Known_Value (Comp) or else (Is_Entity_Name (Comp) and then Present (Entity (Comp)) and then No (Renamed_Object (Entity (Comp)))) or else (Nkind (Comp) = N_Attribute_Reference and then Check_Component (Prefix (Comp))) or else (Nkind (Comp) in N_Binary_Op and then Check_Component (Left_Opnd (Comp)) and then Check_Component (Right_Opnd (Comp))) or else (Nkind (Comp) in N_Unary_Op and then Check_Component (Right_Opnd (Comp))) or else (Nkind (Comp) = N_Selected_Component and then Check_Component (Prefix (Comp))) or else (Nkind (Comp) = N_Unchecked_Type_Conversion and then Check_Component (Expression (Comp))); end Check_Component; -- Start of processing for Safe_Component begin -- If the component appears in an association that may -- correspond to more than one element, it is not analyzed -- before the expansion into assignments, to avoid side effects. -- We analyze, but do not resolve the copy, to obtain sufficient -- entity information for the checks that follow. If component is -- overloaded we assume an unsafe function call. if not Analyzed (Comp) then if Is_Overloaded (Expr) then return False; elsif Nkind (Expr) = N_Aggregate and then not Is_Others_Aggregate (Expr) then return False; elsif Nkind (Expr) = N_Allocator then -- For now, too complex to analyze return False; end if; Comp := New_Copy_Tree (Expr); Set_Parent (Comp, Parent (Expr)); Analyze (Comp); end if; if Nkind (Comp) = N_Aggregate then return Safe_Aggregate (Comp); else return Check_Component (Comp); end if; end Safe_Component; -- Start of processing for In_Place_Assign_OK begin if Present (Component_Associations (N)) then -- On assignment, sliding can take place, so we cannot do the -- assignment in place unless the bounds of the aggregate are -- statically equal to those of the target. -- If the aggregate is given by an others choice, the bounds -- are derived from the left-hand side, and the assignment is -- safe if the expression is. if Is_Others_Aggregate (N) then return Safe_Component (Expression (First (Component_Associations (N)))); end if; Aggr_In := First_Index (Etype (N)); if Nkind (Parent (N)) = N_Assignment_Statement then Obj_In := First_Index (Etype (Name (Parent (N)))); else -- Context is an allocator. Check bounds of aggregate -- against given type in qualified expression. pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator); Obj_In := First_Index (Etype (Entity (Subtype_Mark (Parent (N))))); end if; while Present (Aggr_In) loop Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi); Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi); if not Compile_Time_Known_Value (Aggr_Lo) or else not Compile_Time_Known_Value (Aggr_Hi) or else not Compile_Time_Known_Value (Obj_Lo) or else not Compile_Time_Known_Value (Obj_Hi) or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo) or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi) then return False; end if; Next_Index (Aggr_In); Next_Index (Obj_In); end loop; end if; -- Now check the component values themselves return Safe_Aggregate (N); end In_Place_Assign_OK; ------------------ -- Others_Check -- ------------------ procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is Aggr_Lo : constant Node_Id := Aggr_Low (Dim); Aggr_Hi : constant Node_Id := Aggr_High (Dim); -- The bounds of the aggregate for this dimension Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim); -- The index type for this dimension Need_To_Check : Boolean := False; Choices_Lo : Node_Id := Empty; Choices_Hi : Node_Id := Empty; -- The lowest and highest discrete choices for a named sub-aggregate Nb_Choices : Int := -1; -- The number of discrete non-others choices in this sub-aggregate Nb_Elements : Uint := Uint_0; -- The number of elements in a positional aggregate Cond : Node_Id := Empty; Assoc : Node_Id; Choice : Node_Id; Expr : Node_Id; begin -- Check if we have an others choice. If we do make sure that this -- sub-aggregate contains at least one element in addition to the -- others choice. if Range_Checks_Suppressed (Ind_Typ) then Need_To_Check := False; elsif Present (Expressions (Sub_Aggr)) and then Present (Component_Associations (Sub_Aggr)) then Need_To_Check := True; elsif Present (Component_Associations (Sub_Aggr)) then Assoc := Last (Component_Associations (Sub_Aggr)); if Nkind (First (Choices (Assoc))) /= N_Others_Choice then Need_To_Check := False; else -- Count the number of discrete choices. Start with -1 because -- the others choice does not count. Nb_Choices := -1; Assoc := First (Component_Associations (Sub_Aggr)); while Present (Assoc) loop Choice := First (Choices (Assoc)); while Present (Choice) loop Nb_Choices := Nb_Choices + 1; Next (Choice); end loop; Next (Assoc); end loop; -- If there is only an others choice nothing to do Need_To_Check := (Nb_Choices > 0); end if; else Need_To_Check := False; end if; -- If we are dealing with a positional sub-aggregate with an others -- choice then compute the number or positional elements. if Need_To_Check and then Present (Expressions (Sub_Aggr)) then Expr := First (Expressions (Sub_Aggr)); Nb_Elements := Uint_0; while Present (Expr) loop Nb_Elements := Nb_Elements + 1; Next (Expr); end loop; -- If the aggregate contains discrete choices and an others choice -- compute the smallest and largest discrete choice values. elsif Need_To_Check then Compute_Choices_Lo_And_Choices_Hi : declare Table : Case_Table_Type (1 .. Nb_Choices); -- Used to sort all the different choice values J : Pos := 1; Low : Node_Id; High : Node_Id; begin Assoc := First (Component_Associations (Sub_Aggr)); while Present (Assoc) loop Choice := First (Choices (Assoc)); while Present (Choice) loop if Nkind (Choice) = N_Others_Choice then exit; end if; Get_Index_Bounds (Choice, Low, High); Table (J).Choice_Lo := Low; Table (J).Choice_Hi := High; J := J + 1; Next (Choice); end loop; Next (Assoc); end loop; -- Sort the discrete choices Sort_Case_Table (Table); Choices_Lo := Table (1).Choice_Lo; Choices_Hi := Table (Nb_Choices).Choice_Hi; end Compute_Choices_Lo_And_Choices_Hi; end if; -- If no others choice in this sub-aggregate, or the aggregate -- comprises only an others choice, nothing to do. if not Need_To_Check then Cond := Empty; -- If we are dealing with an aggregate containing an others choice -- and positional components, we generate the following test: -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) > -- Ind_Typ'Pos (Aggr_Hi) -- then -- raise Constraint_Error; -- end if; elsif Nb_Elements > Uint_0 then Cond := Make_Op_Gt (Loc, Left_Opnd => Make_Op_Add (Loc, Left_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Ind_Typ, Loc), Attribute_Name => Name_Pos, Expressions => New_List (Duplicate_Subexpr_Move_Checks (Aggr_Lo))), Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)), Right_Opnd => Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Ind_Typ, Loc), Attribute_Name => Name_Pos, Expressions => New_List ( Duplicate_Subexpr_Move_Checks (Aggr_Hi)))); -- If we are dealing with an aggregate containing an others choice -- and discrete choices we generate the following test: -- [constraint_error when -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi]; else Cond := Make_Or_Else (Loc, Left_Opnd => Make_Op_Lt (Loc, Left_Opnd => Duplicate_Subexpr_Move_Checks (Choices_Lo), Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo)), Right_Opnd => Make_Op_Gt (Loc, Left_Opnd => Duplicate_Subexpr (Choices_Hi), Right_Opnd => Duplicate_Subexpr (Aggr_Hi))); end if; if Present (Cond) then Insert_Action (N, Make_Raise_Constraint_Error (Loc, Condition => Cond, Reason => CE_Length_Check_Failed)); -- Questionable reason code, shouldn't that be a -- CE_Range_Check_Failed ??? end if; -- Now look inside the sub-aggregate to see if there is more work if Dim < Aggr_Dimension then -- Process positional components if Present (Expressions (Sub_Aggr)) then Expr := First (Expressions (Sub_Aggr)); while Present (Expr) loop Others_Check (Expr, Dim + 1); Next (Expr); end loop; end if; -- Process component associations if Present (Component_Associations (Sub_Aggr)) then Assoc := First (Component_Associations (Sub_Aggr)); while Present (Assoc) loop Expr := Expression (Assoc); Others_Check (Expr, Dim + 1); Next (Assoc); end loop; end if; end if; end Others_Check; ------------------------- -- Safe_Left_Hand_Side -- ------------------------- function Safe_Left_Hand_Side (N : Node_Id) return Boolean is function Is_Safe_Index (Indx : Node_Id) return Boolean; -- If the left-hand side includes an indexed component, check that -- the indexes are free of side-effect. ------------------- -- Is_Safe_Index -- ------------------- function Is_Safe_Index (Indx : Node_Id) return Boolean is begin if Is_Entity_Name (Indx) then return True; elsif Nkind (Indx) = N_Integer_Literal then return True; elsif Nkind (Indx) = N_Function_Call and then Is_Entity_Name (Name (Indx)) and then Has_Pragma_Pure_Function (Entity (Name (Indx))) then return True; elsif Nkind (Indx) = N_Type_Conversion and then Is_Safe_Index (Expression (Indx)) then return True; else return False; end if; end Is_Safe_Index; -- Start of processing for Safe_Left_Hand_Side begin if Is_Entity_Name (N) then return True; elsif Nkind_In (N, N_Explicit_Dereference, N_Selected_Component) and then Safe_Left_Hand_Side (Prefix (N)) then return True; elsif Nkind (N) = N_Indexed_Component and then Safe_Left_Hand_Side (Prefix (N)) and then Is_Safe_Index (First (Expressions (N))) then return True; elsif Nkind (N) = N_Unchecked_Type_Conversion then return Safe_Left_Hand_Side (Expression (N)); else return False; end if; end Safe_Left_Hand_Side; -- Local variables Tmp : Entity_Id; -- Holds the temporary aggregate value Tmp_Decl : Node_Id; -- Holds the declaration of Tmp Aggr_Code : List_Id; Parent_Node : Node_Id; Parent_Kind : Node_Kind; -- Start of processing for Expand_Array_Aggregate begin -- Do not touch the special aggregates of attributes used for Asm calls if Is_RTE (Ctyp, RE_Asm_Input_Operand) or else Is_RTE (Ctyp, RE_Asm_Output_Operand) then return; -- Do not expand an aggregate for an array type which contains tasks if -- the aggregate is associated with an unexpanded return statement of a -- build-in-place function. The aggregate is expanded when the related -- return statement (rewritten into an extended return) is processed. -- This delay ensures that any temporaries and initialization code -- generated for the aggregate appear in the proper return block and -- use the correct _chain and _master. elsif Has_Task (Base_Type (Etype (N))) and then Nkind (Parent (N)) = N_Simple_Return_Statement and then Is_Build_In_Place_Function (Return_Applies_To (Return_Statement_Entity (Parent (N)))) then return; end if; -- If the semantic analyzer has determined that aggregate N will raise -- Constraint_Error at run time, then the aggregate node has been -- replaced with an N_Raise_Constraint_Error node and we should -- never get here. pragma Assert (not Raises_Constraint_Error (N)); -- STEP 1a -- Check that the index range defined by aggregate bounds is -- compatible with corresponding index subtype. Index_Compatibility_Check : declare Aggr_Index_Range : Node_Id := First_Index (Typ); -- The current aggregate index range Index_Constraint : Node_Id := First_Index (Etype (Typ)); -- The corresponding index constraint against which we have to -- check the above aggregate index range. begin Compute_Others_Present (N, 1); for J in 1 .. Aggr_Dimension loop -- There is no need to emit a check if an others choice is -- present for this array aggregate dimension since in this -- case one of N's sub-aggregates has taken its bounds from the -- context and these bounds must have been checked already. In -- addition all sub-aggregates corresponding to the same -- dimension must all have the same bounds (checked in (c) below). if not Range_Checks_Suppressed (Etype (Index_Constraint)) and then not Others_Present (J) then -- We don't use Checks.Apply_Range_Check here because it emits -- a spurious check. Namely it checks that the range defined by -- the aggregate bounds is non empty. But we know this already -- if we get here. Check_Bounds (Aggr_Index_Range, Index_Constraint); end if; -- Save the low and high bounds of the aggregate index as well as -- the index type for later use in checks (b) and (c) below. Aggr_Low (J) := Low_Bound (Aggr_Index_Range); Aggr_High (J) := High_Bound (Aggr_Index_Range); Aggr_Index_Typ (J) := Etype (Index_Constraint); Next_Index (Aggr_Index_Range); Next_Index (Index_Constraint); end loop; end Index_Compatibility_Check; -- STEP 1b -- If an others choice is present check that no aggregate index is -- outside the bounds of the index constraint. Others_Check (N, 1); -- STEP 1c -- For multidimensional arrays make sure that all subaggregates -- corresponding to the same dimension have the same bounds. if Aggr_Dimension > 1 then Check_Same_Aggr_Bounds (N, 1); end if; -- STEP 2 -- Here we test for is packed array aggregate that we can handle at -- compile time. If so, return with transformation done. Note that we do -- this even if the aggregate is nested, because once we have done this -- processing, there is no more nested aggregate! if Packed_Array_Aggregate_Handled (N) then return; end if; -- At this point we try to convert to positional form if Ekind (Current_Scope) = E_Package and then Static_Elaboration_Desired (Current_Scope) then Convert_To_Positional (N, Max_Others_Replicate => 100); else Convert_To_Positional (N); end if; -- if the result is no longer an aggregate (e.g. it may be a string -- literal, or a temporary which has the needed value), then we are -- done, since there is no longer a nested aggregate. if Nkind (N) /= N_Aggregate then return; -- We are also done if the result is an analyzed aggregate -- This case could use more comments ??? elsif Analyzed (N) and then N /= Original_Node (N) then return; end if; -- If all aggregate components are compile-time known and the aggregate -- has been flattened, nothing left to do. The same occurs if the -- aggregate is used to initialize the components of an statically -- allocated dispatch table. if Compile_Time_Known_Aggregate (N) or else Is_Static_Dispatch_Table_Aggregate (N) then Set_Expansion_Delayed (N, False); return; end if; -- Now see if back end processing is possible if Backend_Processing_Possible (N) then -- If the aggregate is static but the constraints are not, build -- a static subtype for the aggregate, so that Gigi can place it -- in static memory. Perform an unchecked_conversion to the non- -- static type imposed by the context. declare Itype : constant Entity_Id := Etype (N); Index : Node_Id; Needs_Type : Boolean := False; begin Index := First_Index (Itype); while Present (Index) loop if not Is_Static_Subtype (Etype (Index)) then Needs_Type := True; exit; else Next_Index (Index); end if; end loop; if Needs_Type then Build_Constrained_Type (Positional => True); Rewrite (N, Unchecked_Convert_To (Itype, N)); Analyze (N); end if; end; return; end if; -- STEP 3 -- Delay expansion for nested aggregates: it will be taken care of -- when the parent aggregate is expanded. Parent_Node := Parent (N); Parent_Kind := Nkind (Parent_Node); if Parent_Kind = N_Qualified_Expression then Parent_Node := Parent (Parent_Node); Parent_Kind := Nkind (Parent_Node); end if; if Parent_Kind = N_Aggregate or else Parent_Kind = N_Extension_Aggregate or else Parent_Kind = N_Component_Association or else (Parent_Kind = N_Object_Declaration and then Needs_Finalization (Typ)) or else (Parent_Kind = N_Assignment_Statement and then Inside_Init_Proc) then if Static_Array_Aggregate (N) or else Compile_Time_Known_Aggregate (N) then Set_Expansion_Delayed (N, False); return; else Set_Expansion_Delayed (N); return; end if; end if; -- STEP 4 -- Look if in place aggregate expansion is possible -- For object declarations we build the aggregate in place, unless -- the array is bit-packed or the component is controlled. -- For assignments we do the assignment in place if all the component -- associations have compile-time known values. For other cases we -- create a temporary. The analysis for safety of on-line assignment -- is delicate, i.e. we don't know how to do it fully yet ??? -- For allocators we assign to the designated object in place if the -- aggregate meets the same conditions as other in-place assignments. -- In this case the aggregate may not come from source but was created -- for default initialization, e.g. with Initialize_Scalars. if Requires_Transient_Scope (Typ) then Establish_Transient_Scope (N, Sec_Stack => Has_Controlled_Component (Typ)); end if; if Has_Default_Init_Comps (N) then Maybe_In_Place_OK := False; elsif Is_Bit_Packed_Array (Typ) or else Has_Controlled_Component (Typ) then Maybe_In_Place_OK := False; else Maybe_In_Place_OK := (Nkind (Parent (N)) = N_Assignment_Statement and then Comes_From_Source (N) and then In_Place_Assign_OK) or else (Nkind (Parent (Parent (N))) = N_Allocator and then In_Place_Assign_OK); end if; -- If this is an array of tasks, it will be expanded into build-in-place -- assignments. Build an activation chain for the tasks now. if Has_Task (Etype (N)) then Build_Activation_Chain_Entity (N); end if; -- Should document these individual tests ??? if not Has_Default_Init_Comps (N) and then Comes_From_Source (Parent (N)) and then Nkind (Parent (N)) = N_Object_Declaration and then not Must_Slide (Etype (Defining_Identifier (Parent (N))), Typ) and then N = Expression (Parent (N)) and then not Is_Bit_Packed_Array (Typ) and then not Has_Controlled_Component (Typ) -- If the aggregate is the expression in an object declaration, it -- cannot be expanded in place. Lookahead in the current declarative -- part to find an address clause for the object being declared. If -- one is present, we cannot build in place. Unclear comment??? and then not Has_Following_Address_Clause (Parent (N)) then Tmp := Defining_Identifier (Parent (N)); Set_No_Initialization (Parent (N)); Set_Expression (Parent (N), Empty); -- Set the type of the entity, for use in the analysis of the -- subsequent indexed assignments. If the nominal type is not -- constrained, build a subtype from the known bounds of the -- aggregate. If the declaration has a subtype mark, use it, -- otherwise use the itype of the aggregate. if not Is_Constrained (Typ) then Build_Constrained_Type (Positional => False); elsif Is_Entity_Name (Object_Definition (Parent (N))) and then Is_Constrained (Entity (Object_Definition (Parent (N)))) then Set_Etype (Tmp, Entity (Object_Definition (Parent (N)))); else Set_Size_Known_At_Compile_Time (Typ, False); Set_Etype (Tmp, Typ); end if; elsif Maybe_In_Place_OK and then Nkind (Parent (N)) = N_Qualified_Expression and then Nkind (Parent (Parent (N))) = N_Allocator then Set_Expansion_Delayed (N); return; -- In the remaining cases the aggregate is the RHS of an assignment elsif Maybe_In_Place_OK and then Safe_Left_Hand_Side (Name (Parent (N))) then Tmp := Name (Parent (N)); if Etype (Tmp) /= Etype (N) then Apply_Length_Check (N, Etype (Tmp)); if Nkind (N) = N_Raise_Constraint_Error then -- Static error, nothing further to expand return; end if; end if; elsif Maybe_In_Place_OK and then Nkind (Name (Parent (N))) = N_Slice and then Safe_Slice_Assignment (N) then -- Safe_Slice_Assignment rewrites assignment as a loop return; -- Step 5 -- In place aggregate expansion is not possible else Maybe_In_Place_OK := False; Tmp := Make_Temporary (Loc, 'A', N); Tmp_Decl := Make_Object_Declaration (Loc, Defining_Identifier => Tmp, Object_Definition => New_Occurrence_Of (Typ, Loc)); Set_No_Initialization (Tmp_Decl, True); -- If we are within a loop, the temporary will be pushed on the -- stack at each iteration. If the aggregate is the expression for an -- allocator, it will be immediately copied to the heap and can -- be reclaimed at once. We create a transient scope around the -- aggregate for this purpose. if Ekind (Current_Scope) = E_Loop and then Nkind (Parent (Parent (N))) = N_Allocator then Establish_Transient_Scope (N, False); end if; Insert_Action (N, Tmp_Decl); end if; -- Construct and insert the aggregate code. We can safely suppress index -- checks because this code is guaranteed not to raise CE on index -- checks. However we should *not* suppress all checks. declare Target : Node_Id; begin if Nkind (Tmp) = N_Defining_Identifier then Target := New_Reference_To (Tmp, Loc); else if Has_Default_Init_Comps (N) then -- Ada 2005 (AI-287): This case has not been analyzed??? raise Program_Error; end if; -- Name in assignment is explicit dereference Target := New_Copy (Tmp); end if; Aggr_Code := Build_Array_Aggr_Code (N, Ctype => Ctyp, Index => First_Index (Typ), Into => Target, Scalar_Comp => Is_Scalar_Type (Ctyp)); end; if Comes_From_Source (Tmp) then Insert_Actions_After (Parent (N), Aggr_Code); else Insert_Actions (N, Aggr_Code); end if; -- If the aggregate has been assigned in place, remove the original -- assignment. if Nkind (Parent (N)) = N_Assignment_Statement and then Maybe_In_Place_OK then Rewrite (Parent (N), Make_Null_Statement (Loc)); elsif Nkind (Parent (N)) /= N_Object_Declaration or else Tmp /= Defining_Identifier (Parent (N)) then Rewrite (N, New_Occurrence_Of (Tmp, Loc)); Analyze_And_Resolve (N, Typ); end if; end Expand_Array_Aggregate; ------------------------ -- Expand_N_Aggregate -- ------------------------ procedure Expand_N_Aggregate (N : Node_Id) is begin if Is_Record_Type (Etype (N)) then Expand_Record_Aggregate (N); else Expand_Array_Aggregate (N); end if; exception when RE_Not_Available => return; end Expand_N_Aggregate; ---------------------------------- -- Expand_N_Extension_Aggregate -- ---------------------------------- -- If the ancestor part is an expression, add a component association for -- the parent field. If the type of the ancestor part is not the direct -- parent of the expected type, build recursively the needed ancestors. -- If the ancestor part is a subtype_mark, replace aggregate with a decla- -- ration for a temporary of the expected type, followed by individual -- assignments to the given components. procedure Expand_N_Extension_Aggregate (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); A : constant Node_Id := Ancestor_Part (N); Typ : constant Entity_Id := Etype (N); begin -- If the ancestor is a subtype mark, an init proc must be called -- on the resulting object which thus has to be materialized in -- the front-end if Is_Entity_Name (A) and then Is_Type (Entity (A)) then Convert_To_Assignments (N, Typ); -- The extension aggregate is transformed into a record aggregate -- of the following form (c1 and c2 are inherited components) -- (Exp with c3 => a, c4 => b) -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b) else Set_Etype (N, Typ); if Tagged_Type_Expansion then Expand_Record_Aggregate (N, Orig_Tag => New_Occurrence_Of (Node (First_Elmt (Access_Disp_Table (Typ))), Loc), Parent_Expr => A); -- No tag is needed in the case of a VM else Expand_Record_Aggregate (N, Parent_Expr => A); end if; end if; exception when RE_Not_Available => return; end Expand_N_Extension_Aggregate; ----------------------------- -- Expand_Record_Aggregate -- ----------------------------- procedure Expand_Record_Aggregate (N : Node_Id; Orig_Tag : Node_Id := Empty; Parent_Expr : Node_Id := Empty) is Loc : constant Source_Ptr := Sloc (N); Comps : constant List_Id := Component_Associations (N); Typ : constant Entity_Id := Etype (N); Base_Typ : constant Entity_Id := Base_Type (Typ); Static_Components : Boolean := True; -- Flag to indicate whether all components are compile-time known, -- and the aggregate can be constructed statically and handled by -- the back-end. function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean; -- Returns true if N is an expression of composite type which can be -- fully evaluated at compile time without raising constraint error. -- Such expressions can be passed as is to Gigi without any expansion. -- -- This returns true for N_Aggregate with Compile_Time_Known_Aggregate -- set and constants whose expression is such an aggregate, recursively. function Component_Not_OK_For_Backend return Boolean; -- Check for presence of component which makes it impossible for the -- backend to process the aggregate, thus requiring the use of a series -- of assignment statements. Cases checked for are a nested aggregate -- needing Late_Expansion, the presence of a tagged component which may -- need tag adjustment, and a bit unaligned component reference. -- -- We also force expansion into assignments if a component is of a -- mutable type (including a private type with discriminants) because -- in that case the size of the component to be copied may be smaller -- than the side of the target, and there is no simple way for gigi -- to compute the size of the object to be copied. -- -- NOTE: This is part of the ongoing work to define precisely the -- interface between front-end and back-end handling of aggregates. -- In general it is desirable to pass aggregates as they are to gigi, -- in order to minimize elaboration code. This is one case where the -- semantics of Ada complicate the analysis and lead to anomalies in -- the gcc back-end if the aggregate is not expanded into assignments. function Has_Visible_Private_Ancestor (Id : E) return Boolean; -- If any ancestor of the current type is private, the aggregate -- cannot be built in place. We canot rely on Has_Private_Ancestor, -- because it will not be set when type and its parent are in the -- same scope, and the parent component needs expansion. function Top_Level_Aggregate (N : Node_Id) return Node_Id; -- For nested aggregates return the ultimate enclosing aggregate; for -- non-nested aggregates return N. ---------------------------------------- -- Compile_Time_Known_Composite_Value -- ---------------------------------------- function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean is begin -- If we have an entity name, then see if it is the name of a -- constant and if so, test the corresponding constant value. if Is_Entity_Name (N) then declare E : constant Entity_Id := Entity (N); V : Node_Id; begin if Ekind (E) /= E_Constant then return False; else V := Constant_Value (E); return Present (V) and then Compile_Time_Known_Composite_Value (V); end if; end; -- We have a value, see if it is compile time known else if Nkind (N) = N_Aggregate then return Compile_Time_Known_Aggregate (N); end if; -- All other types of values are not known at compile time return False; end if; end Compile_Time_Known_Composite_Value; ---------------------------------- -- Component_Not_OK_For_Backend -- ---------------------------------- function Component_Not_OK_For_Backend return Boolean is C : Node_Id; Expr_Q : Node_Id; begin if No (Comps) then return False; end if; C := First (Comps); while Present (C) loop -- If the component has box initialization, expansion is needed -- and component is not ready for backend. if Box_Present (C) then return True; end if; if Nkind (Expression (C)) = N_Qualified_Expression then Expr_Q := Expression (Expression (C)); else Expr_Q := Expression (C); end if; -- Return true if the aggregate has any associations for tagged -- components that may require tag adjustment. -- These are cases where the source expression may have a tag that -- could differ from the component tag (e.g., can occur for type -- conversions and formal parameters). (Tag adjustment not needed -- if VM_Target because object tags are implicit in the machine.) if Is_Tagged_Type (Etype (Expr_Q)) and then (Nkind (Expr_Q) = N_Type_Conversion or else (Is_Entity_Name (Expr_Q) and then Ekind (Entity (Expr_Q)) in Formal_Kind)) and then Tagged_Type_Expansion then Static_Components := False; return True; elsif Is_Delayed_Aggregate (Expr_Q) then Static_Components := False; return True; elsif Possible_Bit_Aligned_Component (Expr_Q) then Static_Components := False; return True; end if; if Is_Elementary_Type (Etype (Expr_Q)) then if not Compile_Time_Known_Value (Expr_Q) then Static_Components := False; end if; elsif not Compile_Time_Known_Composite_Value (Expr_Q) then Static_Components := False; if Is_Private_Type (Etype (Expr_Q)) and then Has_Discriminants (Etype (Expr_Q)) then return True; end if; end if; Next (C); end loop; return False; end Component_Not_OK_For_Backend; ----------------------------------- -- Has_Visible_Private_Ancestor -- ----------------------------------- function Has_Visible_Private_Ancestor (Id : E) return Boolean is R : constant Entity_Id := Root_Type (Id); T1 : Entity_Id := Id; begin loop if Is_Private_Type (T1) then return True; elsif T1 = R then return False; else T1 := Etype (T1); end if; end loop; end Has_Visible_Private_Ancestor; ------------------------- -- Top_Level_Aggregate -- ------------------------- function Top_Level_Aggregate (N : Node_Id) return Node_Id is Aggr : Node_Id; begin Aggr := N; while Present (Parent (Aggr)) and then Nkind_In (Parent (Aggr), N_Component_Association, N_Aggregate) loop Aggr := Parent (Aggr); end loop; return Aggr; end Top_Level_Aggregate; -- Local variables Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N); Tag_Value : Node_Id; Comp : Entity_Id; New_Comp : Node_Id; -- Start of processing for Expand_Record_Aggregate begin -- If the aggregate is to be assigned to an atomic variable, we -- have to prevent a piecemeal assignment even if the aggregate -- is to be expanded. We create a temporary for the aggregate, and -- assign the temporary instead, so that the back end can generate -- an atomic move for it. if Is_Atomic (Typ) and then Comes_From_Source (Parent (N)) and then Is_Atomic_Aggregate (N, Typ) then return; -- No special management required for aggregates used to initialize -- statically allocated dispatch tables elsif Is_Static_Dispatch_Table_Aggregate (N) then return; end if; -- Ada 2005 (AI-318-2): We need to convert to assignments if components -- are build-in-place function calls. The assignments will each turn -- into a build-in-place function call. If components are all static, -- we can pass the aggregate to the backend regardless of limitedness. -- Extension aggregates, aggregates in extended return statements, and -- aggregates for C++ imported types must be expanded. if Ada_Version >= Ada_2005 and then Is_Immutably_Limited_Type (Typ) then if not Nkind_In (Parent (N), N_Object_Declaration, N_Component_Association) then Convert_To_Assignments (N, Typ); elsif Nkind (N) = N_Extension_Aggregate or else Convention (Typ) = Convention_CPP then Convert_To_Assignments (N, Typ); elsif not Size_Known_At_Compile_Time (Typ) or else Component_Not_OK_For_Backend or else not Static_Components then Convert_To_Assignments (N, Typ); else Set_Compile_Time_Known_Aggregate (N); Set_Expansion_Delayed (N, False); end if; -- Gigi doesn't properly handle temporaries of variable size so we -- generate it in the front-end elsif not Size_Known_At_Compile_Time (Typ) and then Tagged_Type_Expansion then Convert_To_Assignments (N, Typ); -- Temporaries for controlled aggregates need to be attached to a final -- chain in order to be properly finalized, so it has to be created in -- the front-end elsif Is_Controlled (Typ) or else Has_Controlled_Component (Base_Type (Typ)) then Convert_To_Assignments (N, Typ); -- Ada 2005 (AI-287): In case of default initialized components we -- convert the aggregate into assignments. elsif Has_Default_Init_Comps (N) then Convert_To_Assignments (N, Typ); -- Check components elsif Component_Not_OK_For_Backend then Convert_To_Assignments (N, Typ); -- If an ancestor is private, some components are not inherited and we -- cannot expand into a record aggregate. elsif Has_Visible_Private_Ancestor (Typ) then Convert_To_Assignments (N, Typ); -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi -- is not able to handle the aggregate for Late_Request. elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then Convert_To_Assignments (N, Typ); -- If the tagged types covers interface types we need to initialize all -- hidden components containing pointers to secondary dispatch tables. elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then Convert_To_Assignments (N, Typ); -- If some components are mutable, the size of the aggregate component -- may be distinct from the default size of the type component, so -- we need to expand to insure that the back-end copies the proper -- size of the data. However, if the aggregate is the initial value of -- a constant, the target is immutable and might be built statically -- if components are appropriate. elsif Has_Mutable_Components (Typ) and then (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration or else not Constant_Present (Parent (Top_Level_Aggr)) or else not Static_Components) then Convert_To_Assignments (N, Typ); -- If the type involved has any non-bit aligned components, then we are -- not sure that the back end can handle this case correctly. elsif Type_May_Have_Bit_Aligned_Components (Typ) then Convert_To_Assignments (N, Typ); -- In all other cases, build a proper aggregate handlable by gigi else if Nkind (N) = N_Aggregate then -- If the aggregate is static and can be handled by the back-end, -- nothing left to do. if Static_Components then Set_Compile_Time_Known_Aggregate (N); Set_Expansion_Delayed (N, False); end if; end if; -- If no discriminants, nothing special to do if not Has_Discriminants (Typ) then null; -- Case of discriminants present elsif Is_Derived_Type (Typ) then -- For untagged types, non-stored discriminants are replaced -- with stored discriminants, which are the ones that gigi uses -- to describe the type and its components. Generate_Aggregate_For_Derived_Type : declare Constraints : constant List_Id := New_List; First_Comp : Node_Id; Discriminant : Entity_Id; Decl : Node_Id; Num_Disc : Int := 0; Num_Gird : Int := 0; procedure Prepend_Stored_Values (T : Entity_Id); -- Scan the list of stored discriminants of the type, and add -- their values to the aggregate being built. --------------------------- -- Prepend_Stored_Values -- --------------------------- procedure Prepend_Stored_Values (T : Entity_Id) is begin Discriminant := First_Stored_Discriminant (T); while Present (Discriminant) loop New_Comp := Make_Component_Association (Loc, Choices => New_List (New_Occurrence_Of (Discriminant, Loc)), Expression => New_Copy_Tree ( Get_Discriminant_Value ( Discriminant, Typ, Discriminant_Constraint (Typ)))); if No (First_Comp) then Prepend_To (Component_Associations (N), New_Comp); else Insert_After (First_Comp, New_Comp); end if; First_Comp := New_Comp; Next_Stored_Discriminant (Discriminant); end loop; end Prepend_Stored_Values; -- Start of processing for Generate_Aggregate_For_Derived_Type begin -- Remove the associations for the discriminant of derived type First_Comp := First (Component_Associations (N)); while Present (First_Comp) loop Comp := First_Comp; Next (First_Comp); if Ekind (Entity (First (Choices (Comp)))) = E_Discriminant then Remove (Comp); Num_Disc := Num_Disc + 1; end if; end loop; -- Insert stored discriminant associations in the correct -- order. If there are more stored discriminants than new -- discriminants, there is at least one new discriminant that -- constrains more than one of the stored discriminants. In -- this case we need to construct a proper subtype of the -- parent type, in order to supply values to all the -- components. Otherwise there is one-one correspondence -- between the constraints and the stored discriminants. First_Comp := Empty; Discriminant := First_Stored_Discriminant (Base_Type (Typ)); while Present (Discriminant) loop Num_Gird := Num_Gird + 1; Next_Stored_Discriminant (Discriminant); end loop; -- Case of more stored discriminants than new discriminants if Num_Gird > Num_Disc then -- Create a proper subtype of the parent type, which is the -- proper implementation type for the aggregate, and convert -- it to the intended target type. Discriminant := First_Stored_Discriminant (Base_Type (Typ)); while Present (Discriminant) loop New_Comp := New_Copy_Tree ( Get_Discriminant_Value ( Discriminant, Typ, Discriminant_Constraint (Typ))); Append (New_Comp, Constraints); Next_Stored_Discriminant (Discriminant); end loop; Decl := Make_Subtype_Declaration (Loc, Defining_Identifier => Make_Temporary (Loc, 'T'), Subtype_Indication => Make_Subtype_Indication (Loc, Subtype_Mark => New_Occurrence_Of (Etype (Base_Type (Typ)), Loc), Constraint => Make_Index_Or_Discriminant_Constraint (Loc, Constraints))); Insert_Action (N, Decl); Prepend_Stored_Values (Base_Type (Typ)); Set_Etype (N, Defining_Identifier (Decl)); Set_Analyzed (N); Rewrite (N, Unchecked_Convert_To (Typ, N)); Analyze (N); -- Case where we do not have fewer new discriminants than -- stored discriminants, so in this case we can simply use the -- stored discriminants of the subtype. else Prepend_Stored_Values (Typ); end if; end Generate_Aggregate_For_Derived_Type; end if; if Is_Tagged_Type (Typ) then -- In the tagged case, _parent and _tag component must be created -- Reset Null_Present unconditionally. Tagged records always have -- at least one field (the tag or the parent). Set_Null_Record_Present (N, False); -- When the current aggregate comes from the expansion of an -- extension aggregate, the parent expr is replaced by an -- aggregate formed by selected components of this expr. if Present (Parent_Expr) and then Is_Empty_List (Comps) then Comp := First_Component_Or_Discriminant (Typ); while Present (Comp) loop -- Skip all expander-generated components if not Comes_From_Source (Original_Record_Component (Comp)) then null; else New_Comp := Make_Selected_Component (Loc, Prefix => Unchecked_Convert_To (Typ, Duplicate_Subexpr (Parent_Expr, True)), Selector_Name => New_Occurrence_Of (Comp, Loc)); Append_To (Comps, Make_Component_Association (Loc, Choices => New_List (New_Occurrence_Of (Comp, Loc)), Expression => New_Comp)); Analyze_And_Resolve (New_Comp, Etype (Comp)); end if; Next_Component_Or_Discriminant (Comp); end loop; end if; -- Compute the value for the Tag now, if the type is a root it -- will be included in the aggregate right away, otherwise it will -- be propagated to the parent aggregate. if Present (Orig_Tag) then Tag_Value := Orig_Tag; elsif not Tagged_Type_Expansion then Tag_Value := Empty; else Tag_Value := New_Occurrence_Of (Node (First_Elmt (Access_Disp_Table (Typ))), Loc); end if; -- For a derived type, an aggregate for the parent is formed with -- all the inherited components. if Is_Derived_Type (Typ) then declare First_Comp : Node_Id; Parent_Comps : List_Id; Parent_Aggr : Node_Id; Parent_Name : Node_Id; begin -- Remove the inherited component association from the -- aggregate and store them in the parent aggregate First_Comp := First (Component_Associations (N)); Parent_Comps := New_List; while Present (First_Comp) and then Scope (Original_Record_Component ( Entity (First (Choices (First_Comp))))) /= Base_Typ loop Comp := First_Comp; Next (First_Comp); Remove (Comp); Append (Comp, Parent_Comps); end loop; Parent_Aggr := Make_Aggregate (Loc, Component_Associations => Parent_Comps); Set_Etype (Parent_Aggr, Etype (Base_Type (Typ))); -- Find the _parent component Comp := First_Component (Typ); while Chars (Comp) /= Name_uParent loop Comp := Next_Component (Comp); end loop; Parent_Name := New_Occurrence_Of (Comp, Loc); -- Insert the parent aggregate Prepend_To (Component_Associations (N), Make_Component_Association (Loc, Choices => New_List (Parent_Name), Expression => Parent_Aggr)); -- Expand recursively the parent propagating the right Tag Expand_Record_Aggregate (Parent_Aggr, Tag_Value, Parent_Expr); -- The ancestor part may be a nested aggregate that has -- delayed expansion: recheck now. if Component_Not_OK_For_Backend then Convert_To_Assignments (N, Typ); end if; end; -- For a root type, the tag component is added (unless compiling -- for the VMs, where tags are implicit). elsif Tagged_Type_Expansion then declare Tag_Name : constant Node_Id := New_Occurrence_Of (First_Tag_Component (Typ), Loc); Typ_Tag : constant Entity_Id := RTE (RE_Tag); Conv_Node : constant Node_Id := Unchecked_Convert_To (Typ_Tag, Tag_Value); begin Set_Etype (Conv_Node, Typ_Tag); Prepend_To (Component_Associations (N), Make_Component_Association (Loc, Choices => New_List (Tag_Name), Expression => Conv_Node)); end; end if; end if; end if; end Expand_Record_Aggregate; ---------------------------- -- Has_Default_Init_Comps -- ---------------------------- function Has_Default_Init_Comps (N : Node_Id) return Boolean is Comps : constant List_Id := Component_Associations (N); C : Node_Id; Expr : Node_Id; begin pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate)); if No (Comps) then return False; end if; if Has_Self_Reference (N) then return True; end if; -- Check if any direct component has default initialized components C := First (Comps); while Present (C) loop if Box_Present (C) then return True; end if; Next (C); end loop; -- Recursive call in case of aggregate expression C := First (Comps); while Present (C) loop Expr := Expression (C); if Present (Expr) and then Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate) and then Has_Default_Init_Comps (Expr) then return True; end if; Next (C); end loop; return False; end Has_Default_Init_Comps; -------------------------- -- Is_Delayed_Aggregate -- -------------------------- function Is_Delayed_Aggregate (N : Node_Id) return Boolean is Node : Node_Id := N; Kind : Node_Kind := Nkind (Node); begin if Kind = N_Qualified_Expression then Node := Expression (Node); Kind := Nkind (Node); end if; if Kind /= N_Aggregate and then Kind /= N_Extension_Aggregate then return False; else return Expansion_Delayed (Node); end if; end Is_Delayed_Aggregate; ---------------------------------------- -- Is_Static_Dispatch_Table_Aggregate -- ---------------------------------------- function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is Typ : constant Entity_Id := Base_Type (Etype (N)); begin return Static_Dispatch_Tables and then Tagged_Type_Expansion and then RTU_Loaded (Ada_Tags) -- Avoid circularity when rebuilding the compiler and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags) and then (Typ = RTE (RE_Dispatch_Table_Wrapper) or else Typ = RTE (RE_Address_Array) or else Typ = RTE (RE_Type_Specific_Data) or else Typ = RTE (RE_Tag_Table) or else (RTE_Available (RE_Interface_Data) and then Typ = RTE (RE_Interface_Data)) or else (RTE_Available (RE_Interfaces_Array) and then Typ = RTE (RE_Interfaces_Array)) or else (RTE_Available (RE_Interface_Data_Element) and then Typ = RTE (RE_Interface_Data_Element))); end Is_Static_Dispatch_Table_Aggregate; -------------------- -- Late_Expansion -- -------------------- function Late_Expansion (N : Node_Id; Typ : Entity_Id; Target : Node_Id) return List_Id is begin if Is_Record_Type (Etype (N)) then return Build_Record_Aggr_Code (N, Typ, Target); else pragma Assert (Is_Array_Type (Etype (N))); return Build_Array_Aggr_Code (N => N, Ctype => Component_Type (Etype (N)), Index => First_Index (Typ), Into => Target, Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)), Indexes => No_List); end if; end Late_Expansion; ---------------------------------- -- Make_OK_Assignment_Statement -- ---------------------------------- function Make_OK_Assignment_Statement (Sloc : Source_Ptr; Name : Node_Id; Expression : Node_Id) return Node_Id is begin Set_Assignment_OK (Name); return Make_Assignment_Statement (Sloc, Name, Expression); end Make_OK_Assignment_Statement; ----------------------- -- Number_Of_Choices -- ----------------------- function Number_Of_Choices (N : Node_Id) return Nat is Assoc : Node_Id; Choice : Node_Id; Nb_Choices : Nat := 0; begin if Present (Expressions (N)) then return 0; end if; Assoc := First (Component_Associations (N)); while Present (Assoc) loop Choice := First (Choices (Assoc)); while Present (Choice) loop if Nkind (Choice) /= N_Others_Choice then Nb_Choices := Nb_Choices + 1; end if; Next (Choice); end loop; Next (Assoc); end loop; return Nb_Choices; end Number_Of_Choices; ------------------------------------ -- Packed_Array_Aggregate_Handled -- ------------------------------------ -- The current version of this procedure will handle at compile time -- any array aggregate that meets these conditions: -- One dimensional, bit packed -- Underlying packed type is modular type -- Bounds are within 32-bit Int range -- All bounds and values are static function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is Loc : constant Source_Ptr := Sloc (N); Typ : constant Entity_Id := Etype (N); Ctyp : constant Entity_Id := Component_Type (Typ); Not_Handled : exception; -- Exception raised if this aggregate cannot be handled begin -- For now, handle only one dimensional bit packed arrays if not Is_Bit_Packed_Array (Typ) or else Number_Dimensions (Typ) > 1 or else not Is_Modular_Integer_Type (Packed_Array_Type (Typ)) then return False; end if; if not Is_Scalar_Type (Component_Type (Typ)) and then Has_Non_Standard_Rep (Component_Type (Typ)) then return False; end if; declare Csiz : constant Nat := UI_To_Int (Component_Size (Typ)); Lo : Node_Id; Hi : Node_Id; -- Bounds of index type Lob : Uint; Hib : Uint; -- Values of bounds if compile time known function Get_Component_Val (N : Node_Id) return Uint; -- Given a expression value N of the component type Ctyp, returns a -- value of Csiz (component size) bits representing this value. If -- the value is non-static or any other reason exists why the value -- cannot be returned, then Not_Handled is raised. ----------------------- -- Get_Component_Val -- ----------------------- function Get_Component_Val (N : Node_Id) return Uint is Val : Uint; begin -- We have to analyze the expression here before doing any further -- processing here. The analysis of such expressions is deferred -- till expansion to prevent some problems of premature analysis. Analyze_And_Resolve (N, Ctyp); -- Must have a compile time value. String literals have to be -- converted into temporaries as well, because they cannot easily -- be converted into their bit representation. if not Compile_Time_Known_Value (N) or else Nkind (N) = N_String_Literal then raise Not_Handled; end if; Val := Expr_Rep_Value (N); -- Adjust for bias, and strip proper number of bits if Has_Biased_Representation (Ctyp) then Val := Val - Expr_Value (Type_Low_Bound (Ctyp)); end if; return Val mod Uint_2 ** Csiz; end Get_Component_Val; -- Here we know we have a one dimensional bit packed array begin Get_Index_Bounds (First_Index (Typ), Lo, Hi); -- Cannot do anything if bounds are dynamic if not Compile_Time_Known_Value (Lo) or else not Compile_Time_Known_Value (Hi) then return False; end if; -- Or are silly out of range of int bounds Lob := Expr_Value (Lo); Hib := Expr_Value (Hi); if not UI_Is_In_Int_Range (Lob) or else not UI_Is_In_Int_Range (Hib) then return False; end if; -- At this stage we have a suitable aggregate for handling at compile -- time (the only remaining checks are that the values of expressions -- in the aggregate are compile time known (check is performed by -- Get_Component_Val), and that any subtypes or ranges are statically -- known. -- If the aggregate is not fully positional at this stage, then -- convert it to positional form. Either this will fail, in which -- case we can do nothing, or it will succeed, in which case we have -- succeeded in handling the aggregate, or it will stay an aggregate, -- in which case we have failed to handle this case. if Present (Component_Associations (N)) then Convert_To_Positional (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True); return Nkind (N) /= N_Aggregate; end if; -- Otherwise we are all positional, so convert to proper value declare Lov : constant Int := UI_To_Int (Lob); Hiv : constant Int := UI_To_Int (Hib); Len : constant Nat := Int'Max (0, Hiv - Lov + 1); -- The length of the array (number of elements) Aggregate_Val : Uint; -- Value of aggregate. The value is set in the low order bits of -- this value. For the little-endian case, the values are stored -- from low-order to high-order and for the big-endian case the -- values are stored from high-order to low-order. Note that gigi -- will take care of the conversions to left justify the value in -- the big endian case (because of left justified modular type -- processing), so we do not have to worry about that here. Lit : Node_Id; -- Integer literal for resulting constructed value Shift : Nat; -- Shift count from low order for next value Incr : Int; -- Shift increment for loop Expr : Node_Id; -- Next expression from positional parameters of aggregate begin -- For little endian, we fill up the low order bits of the target -- value. For big endian we fill up the high order bits of the -- target value (which is a left justified modular value). if Bytes_Big_Endian xor Debug_Flag_8 then Shift := Csiz * (Len - 1); Incr := -Csiz; else Shift := 0; Incr := +Csiz; end if; -- Loop to set the values if Len = 0 then Aggregate_Val := Uint_0; else Expr := First (Expressions (N)); Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift; for J in 2 .. Len loop Shift := Shift + Incr; Next (Expr); Aggregate_Val := Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift; end loop; end if; -- Now we can rewrite with the proper value Lit := Make_Integer_Literal (Loc, Intval => Aggregate_Val); Set_Print_In_Hex (Lit); -- Construct the expression using this literal. Note that it is -- important to qualify the literal with its proper modular type -- since universal integer does not have the required range and -- also this is a left justified modular type, which is important -- in the big-endian case. Rewrite (N, Unchecked_Convert_To (Typ, Make_Qualified_Expression (Loc, Subtype_Mark => New_Occurrence_Of (Packed_Array_Type (Typ), Loc), Expression => Lit))); Analyze_And_Resolve (N, Typ); return True; end; end; exception when Not_Handled => return False; end Packed_Array_Aggregate_Handled; ---------------------------- -- Has_Mutable_Components -- ---------------------------- function Has_Mutable_Components (Typ : Entity_Id) return Boolean is Comp : Entity_Id; begin Comp := First_Component (Typ); while Present (Comp) loop if Is_Record_Type (Etype (Comp)) and then Has_Discriminants (Etype (Comp)) and then not Is_Constrained (Etype (Comp)) then return True; end if; Next_Component (Comp); end loop; return False; end Has_Mutable_Components; ------------------------------ -- Initialize_Discriminants -- ------------------------------ procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); Bas : constant Entity_Id := Base_Type (Typ); Par : constant Entity_Id := Etype (Bas); Decl : constant Node_Id := Parent (Par); Ref : Node_Id; begin if Is_Tagged_Type (Bas) and then Is_Derived_Type (Bas) and then Has_Discriminants (Par) and then Has_Discriminants (Bas) and then Number_Discriminants (Bas) /= Number_Discriminants (Par) and then Nkind (Decl) = N_Full_Type_Declaration and then Nkind (Type_Definition (Decl)) = N_Record_Definition and then Present (Variant_Part (Component_List (Type_Definition (Decl)))) and then Nkind (N) /= N_Extension_Aggregate then -- Call init proc to set discriminants. -- There should eventually be a special procedure for this ??? Ref := New_Reference_To (Defining_Identifier (N), Loc); Insert_Actions_After (N, Build_Initialization_Call (Sloc (N), Ref, Typ)); end if; end Initialize_Discriminants; ---------------- -- Must_Slide -- ---------------- function Must_Slide (Obj_Type : Entity_Id; Typ : Entity_Id) return Boolean is L1, L2, H1, H2 : Node_Id; begin -- No sliding if the type of the object is not established yet, if it is -- an unconstrained type whose actual subtype comes from the aggregate, -- or if the two types are identical. if not Is_Array_Type (Obj_Type) then return False; elsif not Is_Constrained (Obj_Type) then return False; elsif Typ = Obj_Type then return False; else -- Sliding can only occur along the first dimension Get_Index_Bounds (First_Index (Typ), L1, H1); Get_Index_Bounds (First_Index (Obj_Type), L2, H2); if not Is_Static_Expression (L1) or else not Is_Static_Expression (L2) or else not Is_Static_Expression (H1) or else not Is_Static_Expression (H2) then return False; else return Expr_Value (L1) /= Expr_Value (L2) or else Expr_Value (H1) /= Expr_Value (H2); end if; end if; end Must_Slide; --------------------------- -- Safe_Slice_Assignment -- --------------------------- function Safe_Slice_Assignment (N : Node_Id) return Boolean is Loc : constant Source_Ptr := Sloc (Parent (N)); Pref : constant Node_Id := Prefix (Name (Parent (N))); Range_Node : constant Node_Id := Discrete_Range (Name (Parent (N))); Expr : Node_Id; L_J : Entity_Id; L_Iter : Node_Id; L_Body : Node_Id; Stat : Node_Id; begin -- Generate: for J in Range loop Pref (J) := Expr; end loop; if Comes_From_Source (N) and then No (Expressions (N)) and then Nkind (First (Choices (First (Component_Associations (N))))) = N_Others_Choice then Expr := Expression (First (Component_Associations (N))); L_J := Make_Temporary (Loc, 'J'); L_Iter := Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => L_J, Discrete_Subtype_Definition => Relocate_Node (Range_Node))); L_Body := Make_Assignment_Statement (Loc, Name => Make_Indexed_Component (Loc, Prefix => Relocate_Node (Pref), Expressions => New_List (New_Occurrence_Of (L_J, Loc))), Expression => Relocate_Node (Expr)); -- Construct the final loop Stat := Make_Implicit_Loop_Statement (Node => Parent (N), Identifier => Empty, Iteration_Scheme => L_Iter, Statements => New_List (L_Body)); -- Set type of aggregate to be type of lhs in assignment, -- to suppress redundant length checks. Set_Etype (N, Etype (Name (Parent (N)))); Rewrite (Parent (N), Stat); Analyze (Parent (N)); return True; else return False; end if; end Safe_Slice_Assignment; --------------------- -- Sort_Case_Table -- --------------------- procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is L : constant Int := Case_Table'First; U : constant Int := Case_Table'Last; K : Int; J : Int; T : Case_Bounds; begin K := L; while K /= U loop T := Case_Table (K + 1); J := K + 1; while J /= L and then Expr_Value (Case_Table (J - 1).Choice_Lo) > Expr_Value (T.Choice_Lo) loop Case_Table (J) := Case_Table (J - 1); J := J - 1; end loop; Case_Table (J) := T; K := K + 1; end loop; end Sort_Case_Table; ---------------------------- -- Static_Array_Aggregate -- ---------------------------- function Static_Array_Aggregate (N : Node_Id) return Boolean is Bounds : constant Node_Id := Aggregate_Bounds (N); Typ : constant Entity_Id := Etype (N); Comp_Type : constant Entity_Id := Component_Type (Typ); Agg : Node_Id; Expr : Node_Id; Lo : Node_Id; Hi : Node_Id; begin if Is_Tagged_Type (Typ) or else Is_Controlled (Typ) or else Is_Packed (Typ) then return False; end if; if Present (Bounds) and then Nkind (Bounds) = N_Range and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal and then Nkind (High_Bound (Bounds)) = N_Integer_Literal then Lo := Low_Bound (Bounds); Hi := High_Bound (Bounds); if No (Component_Associations (N)) then -- Verify that all components are static integers Expr := First (Expressions (N)); while Present (Expr) loop if Nkind (Expr) /= N_Integer_Literal then return False; end if; Next (Expr); end loop; return True; else -- We allow only a single named association, either a static -- range or an others_clause, with a static expression. Expr := First (Component_Associations (N)); if Present (Expressions (N)) then return False; elsif Present (Next (Expr)) then return False; elsif Present (Next (First (Choices (Expr)))) then return False; else -- The aggregate is static if all components are literals, -- or else all its components are static aggregates for the -- component type. We also limit the size of a static aggregate -- to prevent runaway static expressions. if Is_Array_Type (Comp_Type) or else Is_Record_Type (Comp_Type) then if Nkind (Expression (Expr)) /= N_Aggregate or else not Compile_Time_Known_Aggregate (Expression (Expr)) then return False; end if; elsif Nkind (Expression (Expr)) /= N_Integer_Literal then return False; end if; if not Aggr_Size_OK (N, Typ) then return False; end if; -- Create a positional aggregate with the right number of -- copies of the expression. Agg := Make_Aggregate (Sloc (N), New_List, No_List); for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi)) loop Append_To (Expressions (Agg), New_Copy (Expression (Expr))); -- The copied expression must be analyzed and resolved. -- Besides setting the type, this ensures that static -- expressions are appropriately marked as such. Analyze_And_Resolve (Last (Expressions (Agg)), Component_Type (Typ)); end loop; Set_Aggregate_Bounds (Agg, Bounds); Set_Etype (Agg, Typ); Set_Analyzed (Agg); Rewrite (N, Agg); Set_Compile_Time_Known_Aggregate (N); return True; end if; end if; else return False; end if; end Static_Array_Aggregate; end Exp_Aggr;
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