| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- E X P _ A T T R -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2022, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
| -- http://www.gnu.org/licenses for a complete copy of the license. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Aspects; use Aspects; |
| with Atree; use Atree; |
| with Checks; use Checks; |
| with Einfo; use Einfo; |
| with Einfo.Entities; use Einfo.Entities; |
| with Einfo.Utils; use Einfo.Utils; |
| with Elists; use Elists; |
| with Exp_Atag; use Exp_Atag; |
| with Exp_Ch3; use Exp_Ch3; |
| with Exp_Ch6; use Exp_Ch6; |
| with Exp_Ch9; use Exp_Ch9; |
| with Exp_Dist; use Exp_Dist; |
| with Exp_Imgv; use Exp_Imgv; |
| with Exp_Pakd; use Exp_Pakd; |
| with Exp_Strm; use Exp_Strm; |
| with Exp_Put_Image; |
| with Exp_Tss; use Exp_Tss; |
| with Exp_Util; use Exp_Util; |
| with Expander; use Expander; |
| with Freeze; use Freeze; |
| with Gnatvsn; use Gnatvsn; |
| 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 Sem; use Sem; |
| with Sem_Aux; use Sem_Aux; |
| with Sem_Ch6; use Sem_Ch6; |
| with Sem_Ch7; use Sem_Ch7; |
| with Sem_Ch8; use Sem_Ch8; |
| with Sem_Eval; use Sem_Eval; |
| with Sem_Res; use Sem_Res; |
| with Sem_Util; use Sem_Util; |
| with Sinfo; use Sinfo; |
| with Sinfo.Nodes; use Sinfo.Nodes; |
| with Sinfo.Utils; use Sinfo.Utils; |
| with Snames; use Snames; |
| with Stand; use Stand; |
| with Stringt; use Stringt; |
| with Strub; use Strub; |
| with Tbuild; use Tbuild; |
| with Ttypes; use Ttypes; |
| with Uintp; use Uintp; |
| with Uname; use Uname; |
| with Urealp; use Urealp; |
| with Validsw; use Validsw; |
| |
| package body Exp_Attr is |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| function Build_Array_VS_Func |
| (Attr : Node_Id; |
| Formal_Typ : Entity_Id; |
| Array_Typ : Entity_Id) return Entity_Id; |
| -- Validate the components of an array type by means of a function. Return |
| -- the entity of the validation function. The parameters are as follows: |
| -- |
| -- * Attr - the 'Valid_Scalars attribute for which the function is |
| -- generated. |
| -- |
| -- * Formal_Typ - the type of the generated function's only formal |
| -- parameter. |
| -- |
| -- * Array_Typ - the array type whose components are to be validated |
| |
| function Build_Disp_Get_Task_Id_Call (Actual : Node_Id) return Node_Id; |
| -- Build a call to Disp_Get_Task_Id, passing Actual as actual parameter |
| |
| function Build_Record_VS_Func |
| (Attr : Node_Id; |
| Formal_Typ : Entity_Id; |
| Rec_Typ : Entity_Id) return Entity_Id; |
| -- Validate the components, discriminants, and variants of a record type by |
| -- means of a function. Return the entity of the validation function. The |
| -- parameters are as follows: |
| -- |
| -- * Attr - the 'Valid_Scalars attribute for which the function is |
| -- generated. |
| -- |
| -- * Formal_Typ - the type of the generated function's only formal |
| -- parameter. |
| -- |
| -- * Rec_Typ - the record type whose internals are to be validated |
| |
| procedure Compile_Stream_Body_In_Scope |
| (N : Node_Id; |
| Decl : Node_Id; |
| Arr : Entity_Id); |
| -- The body for a stream subprogram may be generated outside of the scope |
| -- of the type. If the type is fully private, it may depend on the full |
| -- view of other types (e.g. indexes) that are currently private as well. |
| -- We install the declarations of the package in which the type is declared |
| -- before compiling the body in what is its proper environment. The Check |
| -- parameter indicates if checks are to be suppressed for the stream body. |
| -- We suppress checks for array/record reads, since the rule is that these |
| -- are like assignments, out of range values due to uninitialized storage, |
| -- or other invalid values do NOT cause a Constraint_Error to be raised. |
| -- If we are within an instance body all visibility has been established |
| -- already and there is no need to install the package. |
| |
| -- This mechanism is now extended to the component types of the array type, |
| -- when the component type is not in scope and is private, to handle |
| -- properly the case when the full view has defaulted discriminants. |
| |
| -- This special processing is ultimately caused by the fact that the |
| -- compiler lacks a well-defined phase when full views are visible |
| -- everywhere. Having such a separate pass would remove much of the |
| -- special-case code that shuffles partial and full views in the middle |
| -- of semantic analysis and expansion. |
| |
| function Default_Streaming_Unavailable (Typ : Entity_Id) return Boolean; |
| -- |
| -- In most cases, references to unavailable streaming attributes |
| -- are rejected at compile time. In some obscure cases involving |
| -- generics and formal derived types, the problem is dealt with at runtime. |
| |
| procedure Expand_Access_To_Protected_Op |
| (N : Node_Id; |
| Pref : Node_Id; |
| Typ : Entity_Id); |
| -- An attribute reference to a protected subprogram is transformed into |
| -- a pair of pointers: one to the object, and one to the operations. |
| -- This expansion is performed for 'Access and for 'Unrestricted_Access. |
| |
| procedure Expand_Fpt_Attribute |
| (N : Node_Id; |
| Pkg : RE_Id; |
| Nam : Name_Id; |
| Args : List_Id); |
| -- This procedure expands a call to a floating-point attribute function. |
| -- N is the attribute reference node, and Args is a list of arguments to |
| -- be passed to the function call. Pkg identifies the package containing |
| -- the appropriate instantiation of System.Fat_Gen. Float arguments in Args |
| -- have already been converted to the floating-point type for which Pkg was |
| -- instantiated. The Nam argument is the relevant attribute processing |
| -- routine to be called. This is the same as the attribute name. |
| |
| procedure Expand_Fpt_Attribute_R (N : Node_Id); |
| -- This procedure expands a call to a floating-point attribute function |
| -- that takes a single floating-point argument. The function to be called |
| -- is always the same as the attribute name. |
| |
| procedure Expand_Fpt_Attribute_RI (N : Node_Id); |
| -- This procedure expands a call to a floating-point attribute function |
| -- that takes one floating-point argument and one integer argument. The |
| -- function to be called is always the same as the attribute name. |
| |
| procedure Expand_Fpt_Attribute_RR (N : Node_Id); |
| -- This procedure expands a call to a floating-point attribute function |
| -- that takes two floating-point arguments. The function to be called |
| -- is always the same as the attribute name. |
| |
| procedure Expand_Loop_Entry_Attribute (N : Node_Id); |
| -- Handle the expansion of attribute 'Loop_Entry. As a result, the related |
| -- loop may be converted into a conditional block. See body for details. |
| |
| procedure Expand_Min_Max_Attribute (N : Node_Id); |
| -- Handle the expansion of attributes 'Max and 'Min, including expanding |
| -- then out if we are in Modify_Tree_For_C mode. |
| |
| procedure Expand_Pred_Succ_Attribute (N : Node_Id); |
| -- Handles expansion of Pred or Succ attributes for case of non-real |
| -- operand with overflow checking required. |
| |
| procedure Expand_Update_Attribute (N : Node_Id); |
| -- Handle the expansion of attribute Update |
| |
| procedure Find_Fat_Info |
| (T : Entity_Id; |
| Fat_Type : out Entity_Id; |
| Fat_Pkg : out RE_Id); |
| -- Given a floating-point type T, identifies the package containing the |
| -- attributes for this type (returned in Fat_Pkg), and the corresponding |
| -- type for which this package was instantiated from Fat_Gen. Error if T |
| -- is not a floating-point type. |
| |
| function Find_Stream_Subprogram |
| (Typ : Entity_Id; |
| Nam : TSS_Name_Type) return Entity_Id; |
| -- Returns the stream-oriented subprogram attribute for Typ. For tagged |
| -- types, the corresponding primitive operation is looked up, else the |
| -- appropriate TSS from the type itself, or from its closest ancestor |
| -- defining it, is returned. In both cases, inheritance of representation |
| -- aspects is thus taken into account. |
| |
| function Full_Base (T : Entity_Id) return Entity_Id; |
| -- The stream functions need to examine the underlying representation of |
| -- composite types. In some cases T may be non-private but its base type |
| -- is, in which case the function returns the corresponding full view. |
| |
| function Get_Stream_Convert_Pragma (T : Entity_Id) return Node_Id; |
| -- Given a type, find a corresponding stream convert pragma that applies to |
| -- the implementation base type of this type (Typ). If found, return the |
| -- pragma node, otherwise return Empty if no pragma is found. |
| |
| function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean; |
| -- Utility for array attributes, returns true on packed constrained |
| -- arrays, and on access to same. |
| |
| function Is_Inline_Floating_Point_Attribute (N : Node_Id) return Boolean; |
| -- Returns true iff the given node refers to an attribute call that |
| -- can be expanded directly by the back end and does not need front end |
| -- expansion. Typically used for rounding and truncation attributes that |
| -- appear directly inside a conversion to integer. |
| |
| ------------------------- |
| -- Build_Array_VS_Func -- |
| ------------------------- |
| |
| function Build_Array_VS_Func |
| (Attr : Node_Id; |
| Formal_Typ : Entity_Id; |
| Array_Typ : Entity_Id) return Entity_Id |
| is |
| Loc : constant Source_Ptr := Sloc (Attr); |
| Comp_Typ : constant Entity_Id := |
| Validated_View (Component_Type (Array_Typ)); |
| |
| function Validate_Component |
| (Obj_Id : Entity_Id; |
| Indexes : List_Id) return Node_Id; |
| -- Process a single component denoted by indexes Indexes. Obj_Id denotes |
| -- the entity of the validation parameter. Return the check associated |
| -- with the component. |
| |
| function Validate_Dimension |
| (Obj_Id : Entity_Id; |
| Dim : Int; |
| Indexes : List_Id) return Node_Id; |
| -- Process dimension Dim of the array type. Obj_Id denotes the entity |
| -- of the validation parameter. Indexes is a list where each dimension |
| -- deposits its loop variable, which will later identify a component. |
| -- Return the loop associated with the current dimension. |
| |
| ------------------------ |
| -- Validate_Component -- |
| ------------------------ |
| |
| function Validate_Component |
| (Obj_Id : Entity_Id; |
| Indexes : List_Id) return Node_Id |
| is |
| Attr_Nam : Name_Id; |
| |
| begin |
| if Is_Scalar_Type (Comp_Typ) then |
| Attr_Nam := Name_Valid; |
| else |
| Attr_Nam := Name_Valid_Scalars; |
| end if; |
| |
| -- Generate: |
| -- if not Array_Typ (Obj_Id) (Indexes)'Valid[_Scalars] then |
| -- return False; |
| -- end if; |
| |
| return |
| Make_If_Statement (Loc, |
| Condition => |
| Make_Op_Not (Loc, |
| Right_Opnd => |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Unchecked_Convert_To (Array_Typ, |
| New_Occurrence_Of (Obj_Id, Loc)), |
| Expressions => Indexes), |
| Attribute_Name => Attr_Nam)), |
| |
| Then_Statements => New_List ( |
| Make_Simple_Return_Statement (Loc, |
| Expression => New_Occurrence_Of (Standard_False, Loc)))); |
| end Validate_Component; |
| |
| ------------------------ |
| -- Validate_Dimension -- |
| ------------------------ |
| |
| function Validate_Dimension |
| (Obj_Id : Entity_Id; |
| Dim : Int; |
| Indexes : List_Id) return Node_Id |
| is |
| Index : Entity_Id; |
| |
| begin |
| -- Validate the component once all dimensions have produced their |
| -- individual loops. |
| |
| if Dim > Number_Dimensions (Array_Typ) then |
| return Validate_Component (Obj_Id, Indexes); |
| |
| -- Process the current dimension |
| |
| else |
| Index := |
| Make_Defining_Identifier (Loc, New_External_Name ('J', Dim)); |
| |
| Append_To (Indexes, New_Occurrence_Of (Index, Loc)); |
| |
| -- Generate: |
| -- for J1 in Array_Typ (Obj_Id)'Range (1) loop |
| -- for JN in Array_Typ (Obj_Id)'Range (N) loop |
| -- if not Array_Typ (Obj_Id) (Indexes)'Valid[_Scalars] |
| -- then |
| -- return False; |
| -- end if; |
| -- end loop; |
| -- end loop; |
| |
| return |
| Make_Implicit_Loop_Statement (Attr, |
| Identifier => Empty, |
| Iteration_Scheme => |
| Make_Iteration_Scheme (Loc, |
| Loop_Parameter_Specification => |
| Make_Loop_Parameter_Specification (Loc, |
| Defining_Identifier => Index, |
| Discrete_Subtype_Definition => |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| Unchecked_Convert_To (Array_Typ, |
| New_Occurrence_Of (Obj_Id, Loc)), |
| Attribute_Name => Name_Range, |
| Expressions => New_List ( |
| Make_Integer_Literal (Loc, Dim))))), |
| Statements => New_List ( |
| Validate_Dimension (Obj_Id, Dim + 1, Indexes))); |
| end if; |
| end Validate_Dimension; |
| |
| -- Local variables |
| |
| Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V'); |
| Indexes : constant List_Id := New_List; |
| Obj_Id : constant Entity_Id := Make_Temporary (Loc, 'A'); |
| Stmts : List_Id; |
| |
| -- Start of processing for Build_Array_VS_Func |
| |
| begin |
| Stmts := New_List (Validate_Dimension (Obj_Id, 1, Indexes)); |
| |
| -- Generate: |
| -- return True; |
| |
| Append_To (Stmts, |
| Make_Simple_Return_Statement (Loc, |
| Expression => New_Occurrence_Of (Standard_True, Loc))); |
| |
| -- Generate: |
| -- function Func_Id (Obj_Id : Formal_Typ) return Boolean is |
| -- begin |
| -- Stmts |
| -- end Func_Id; |
| |
| Mutate_Ekind (Func_Id, E_Function); |
| Set_Is_Internal (Func_Id); |
| Set_Is_Pure (Func_Id); |
| |
| if not Debug_Generated_Code then |
| Set_Debug_Info_Off (Func_Id); |
| end if; |
| |
| Insert_Action (Attr, |
| Make_Subprogram_Body (Loc, |
| Specification => |
| Make_Function_Specification (Loc, |
| Defining_Unit_Name => Func_Id, |
| Parameter_Specifications => New_List ( |
| Make_Parameter_Specification (Loc, |
| Defining_Identifier => Obj_Id, |
| Parameter_Type => New_Occurrence_Of (Formal_Typ, Loc))), |
| Result_Definition => |
| New_Occurrence_Of (Standard_Boolean, Loc)), |
| Declarations => New_List, |
| Handled_Statement_Sequence => |
| Make_Handled_Sequence_Of_Statements (Loc, |
| Statements => Stmts))); |
| |
| return Func_Id; |
| end Build_Array_VS_Func; |
| |
| --------------------------------- |
| -- Build_Disp_Get_Task_Id_Call -- |
| --------------------------------- |
| |
| function Build_Disp_Get_Task_Id_Call (Actual : Node_Id) return Node_Id is |
| Loc : constant Source_Ptr := Sloc (Actual); |
| Typ : constant Entity_Id := Etype (Actual); |
| Subp : constant Entity_Id := Find_Prim_Op (Typ, Name_uDisp_Get_Task_Id); |
| |
| begin |
| -- Generate: |
| -- _Disp_Get_Task_Id (Actual) |
| |
| return |
| Make_Function_Call (Loc, |
| Name => New_Occurrence_Of (Subp, Loc), |
| Parameter_Associations => New_List (Actual)); |
| end Build_Disp_Get_Task_Id_Call; |
| |
| -------------------------- |
| -- Build_Record_VS_Func -- |
| -------------------------- |
| |
| function Build_Record_VS_Func |
| (Attr : Node_Id; |
| Formal_Typ : Entity_Id; |
| Rec_Typ : Entity_Id) return Entity_Id |
| is |
| -- NOTE: The logic of Build_Record_VS_Func is intentionally passive. |
| -- It generates code only when there are components, discriminants, |
| -- or variant parts to validate. |
| |
| -- NOTE: The routines within Build_Record_VS_Func are intentionally |
| -- unnested to avoid deep indentation of code. |
| |
| Loc : constant Source_Ptr := Sloc (Attr); |
| |
| procedure Validate_Component_List |
| (Obj_Id : Entity_Id; |
| Comp_List : Node_Id; |
| Stmts : in out List_Id); |
| -- Process all components and variant parts of component list Comp_List. |
| -- Obj_Id denotes the entity of the validation parameter. All new code |
| -- is added to list Stmts. |
| |
| procedure Validate_Field |
| (Obj_Id : Entity_Id; |
| Field : Node_Id; |
| Cond : in out Node_Id); |
| -- Process component declaration or discriminant specification Field. |
| -- Obj_Id denotes the entity of the validation parameter. Cond denotes |
| -- an "or else" conditional expression which contains the new code (if |
| -- any). |
| |
| procedure Validate_Fields |
| (Obj_Id : Entity_Id; |
| Fields : List_Id; |
| Stmts : in out List_Id); |
| -- Process component declarations or discriminant specifications in list |
| -- Fields. Obj_Id denotes the entity of the validation parameter. All |
| -- new code is added to list Stmts. |
| |
| procedure Validate_Variant |
| (Obj_Id : Entity_Id; |
| Var : Node_Id; |
| Alts : in out List_Id); |
| -- Process variant Var. Obj_Id denotes the entity of the validation |
| -- parameter. Alts denotes a list of case statement alternatives which |
| -- contains the new code (if any). |
| |
| procedure Validate_Variant_Part |
| (Obj_Id : Entity_Id; |
| Var_Part : Node_Id; |
| Stmts : in out List_Id); |
| -- Process variant part Var_Part. Obj_Id denotes the entity of the |
| -- validation parameter. All new code is added to list Stmts. |
| |
| ----------------------------- |
| -- Validate_Component_List -- |
| ----------------------------- |
| |
| procedure Validate_Component_List |
| (Obj_Id : Entity_Id; |
| Comp_List : Node_Id; |
| Stmts : in out List_Id) |
| is |
| Var_Part : constant Node_Id := Variant_Part (Comp_List); |
| |
| begin |
| -- Validate all components |
| |
| Validate_Fields |
| (Obj_Id => Obj_Id, |
| Fields => Component_Items (Comp_List), |
| Stmts => Stmts); |
| |
| -- Validate the variant part |
| |
| if Present (Var_Part) then |
| Validate_Variant_Part |
| (Obj_Id => Obj_Id, |
| Var_Part => Var_Part, |
| Stmts => Stmts); |
| end if; |
| end Validate_Component_List; |
| |
| -------------------- |
| -- Validate_Field -- |
| -------------------- |
| |
| procedure Validate_Field |
| (Obj_Id : Entity_Id; |
| Field : Node_Id; |
| Cond : in out Node_Id) |
| is |
| Field_Id : constant Entity_Id := Defining_Entity (Field); |
| Field_Nam : constant Name_Id := Chars (Field_Id); |
| Field_Typ : constant Entity_Id := Validated_View (Etype (Field_Id)); |
| Attr_Nam : Name_Id; |
| |
| begin |
| -- Do not process internally-generated fields. Note that checking for |
| -- Comes_From_Source is not correct because this will eliminate the |
| -- components within the corresponding record of a protected type. |
| |
| if Field_Nam in Name_uObject | Name_uParent | Name_uTag then |
| null; |
| |
| -- Do not process fields without any scalar components |
| |
| elsif not Scalar_Part_Present (Field_Typ) then |
| null; |
| |
| -- Otherwise the field needs to be validated. Use Make_Identifier |
| -- rather than New_Occurrence_Of to identify the field because the |
| -- wrong entity may be picked up when private types are involved. |
| |
| -- Generate: |
| -- [or else] not Rec_Typ (Obj_Id).Item_Nam'Valid[_Scalars] |
| |
| else |
| if Is_Scalar_Type (Field_Typ) then |
| Attr_Nam := Name_Valid; |
| else |
| Attr_Nam := Name_Valid_Scalars; |
| end if; |
| |
| Evolve_Or_Else (Cond, |
| Make_Op_Not (Loc, |
| Right_Opnd => |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| Make_Selected_Component (Loc, |
| Prefix => |
| Unchecked_Convert_To (Rec_Typ, |
| New_Occurrence_Of (Obj_Id, Loc)), |
| Selector_Name => Make_Identifier (Loc, Field_Nam)), |
| Attribute_Name => Attr_Nam))); |
| end if; |
| end Validate_Field; |
| |
| --------------------- |
| -- Validate_Fields -- |
| --------------------- |
| |
| procedure Validate_Fields |
| (Obj_Id : Entity_Id; |
| Fields : List_Id; |
| Stmts : in out List_Id) |
| is |
| Cond : Node_Id; |
| Field : Node_Id; |
| |
| begin |
| -- Assume that none of the fields are eligible for verification |
| |
| Cond := Empty; |
| |
| -- Validate all fields |
| |
| Field := First_Non_Pragma (Fields); |
| while Present (Field) loop |
| Validate_Field |
| (Obj_Id => Obj_Id, |
| Field => Field, |
| Cond => Cond); |
| |
| Next_Non_Pragma (Field); |
| end loop; |
| |
| -- Generate: |
| -- if not Rec_Typ (Obj_Id).Item_Nam_1'Valid[_Scalars] |
| -- or else not Rec_Typ (Obj_Id).Item_Nam_N'Valid[_Scalars] |
| -- then |
| -- return False; |
| -- end if; |
| |
| if Present (Cond) then |
| Append_New_To (Stmts, |
| Make_Implicit_If_Statement (Attr, |
| Condition => Cond, |
| Then_Statements => New_List ( |
| Make_Simple_Return_Statement (Loc, |
| Expression => New_Occurrence_Of (Standard_False, Loc))))); |
| end if; |
| end Validate_Fields; |
| |
| ---------------------- |
| -- Validate_Variant -- |
| ---------------------- |
| |
| procedure Validate_Variant |
| (Obj_Id : Entity_Id; |
| Var : Node_Id; |
| Alts : in out List_Id) |
| is |
| Stmts : List_Id; |
| |
| begin |
| -- Assume that none of the components and variants are eligible for |
| -- verification. |
| |
| Stmts := No_List; |
| |
| -- Validate components |
| |
| Validate_Component_List |
| (Obj_Id => Obj_Id, |
| Comp_List => Component_List (Var), |
| Stmts => Stmts); |
| |
| -- Generate a null statement in case none of the components were |
| -- verified because this will otherwise eliminate an alternative |
| -- from the variant case statement and render the generated code |
| -- illegal. |
| |
| if No (Stmts) then |
| Append_New_To (Stmts, Make_Null_Statement (Loc)); |
| end if; |
| |
| -- Generate: |
| -- when Discrete_Choices => |
| -- Stmts |
| |
| Append_New_To (Alts, |
| Make_Case_Statement_Alternative (Loc, |
| Discrete_Choices => |
| New_Copy_List_Tree (Discrete_Choices (Var)), |
| Statements => Stmts)); |
| end Validate_Variant; |
| |
| --------------------------- |
| -- Validate_Variant_Part -- |
| --------------------------- |
| |
| procedure Validate_Variant_Part |
| (Obj_Id : Entity_Id; |
| Var_Part : Node_Id; |
| Stmts : in out List_Id) |
| is |
| Vars : constant List_Id := Variants (Var_Part); |
| Alts : List_Id; |
| Var : Node_Id; |
| |
| begin |
| -- Assume that none of the variants are eligible for verification |
| |
| Alts := No_List; |
| |
| -- Validate variants |
| |
| Var := First_Non_Pragma (Vars); |
| while Present (Var) loop |
| Validate_Variant |
| (Obj_Id => Obj_Id, |
| Var => Var, |
| Alts => Alts); |
| |
| Next_Non_Pragma (Var); |
| end loop; |
| |
| -- Even though individual variants may lack eligible components, the |
| -- alternatives must still be generated. |
| |
| pragma Assert (Present (Alts)); |
| |
| -- Generate: |
| -- case Rec_Typ (Obj_Id).Discriminant is |
| -- when Discrete_Choices_1 => |
| -- Stmts_1 |
| -- when Discrete_Choices_N => |
| -- Stmts_N |
| -- end case; |
| |
| Append_New_To (Stmts, |
| Make_Case_Statement (Loc, |
| Expression => |
| Make_Selected_Component (Loc, |
| Prefix => |
| Unchecked_Convert_To (Rec_Typ, |
| New_Occurrence_Of (Obj_Id, Loc)), |
| Selector_Name => New_Copy_Tree (Name (Var_Part))), |
| Alternatives => Alts)); |
| end Validate_Variant_Part; |
| |
| -- Local variables |
| |
| Func_Id : constant Entity_Id := Make_Temporary (Loc, 'V'); |
| Obj_Id : constant Entity_Id := Make_Temporary (Loc, 'R'); |
| Comps : Node_Id; |
| Stmts : List_Id; |
| Typ : Entity_Id; |
| Typ_Decl : Node_Id; |
| Typ_Def : Node_Id; |
| Typ_Ext : Node_Id; |
| |
| -- Start of processing for Build_Record_VS_Func |
| |
| begin |
| Typ := Validated_View (Rec_Typ); |
| |
| -- Use the root type when dealing with a class-wide type |
| |
| if Is_Class_Wide_Type (Typ) then |
| Typ := Validated_View (Root_Type (Typ)); |
| end if; |
| |
| Typ_Decl := Declaration_Node (Typ); |
| Typ_Def := Type_Definition (Typ_Decl); |
| |
| -- The components of a derived type are located in the extension part |
| |
| if Nkind (Typ_Def) = N_Derived_Type_Definition then |
| Typ_Ext := Record_Extension_Part (Typ_Def); |
| |
| if Present (Typ_Ext) then |
| Comps := Component_List (Typ_Ext); |
| else |
| Comps := Empty; |
| end if; |
| |
| -- Otherwise the components are available in the definition |
| |
| else |
| Comps := Component_List (Typ_Def); |
| end if; |
| |
| -- The code generated by this routine is as follows: |
| -- |
| -- function Func_Id (Obj_Id : Formal_Typ) return Boolean is |
| -- begin |
| -- if not Rec_Typ (Obj_Id).Discriminant_1'Valid[_Scalars] |
| -- or else not Rec_Typ (Obj_Id).Discriminant_N'Valid[_Scalars] |
| -- then |
| -- return False; |
| -- end if; |
| -- |
| -- if not Rec_Typ (Obj_Id).Component_1'Valid[_Scalars] |
| -- or else not Rec_Typ (Obj_Id).Component_N'Valid[_Scalars] |
| -- then |
| -- return False; |
| -- end if; |
| -- |
| -- case Discriminant_1 is |
| -- when Choice_1 => |
| -- if not Rec_Typ (Obj_Id).Component_1'Valid[_Scalars] |
| -- or else not Rec_Typ (Obj_Id).Component_N'Valid[_Scalars] |
| -- then |
| -- return False; |
| -- end if; |
| -- |
| -- case Discriminant_N is |
| -- ... |
| -- when Choice_N => |
| -- ... |
| -- end case; |
| -- |
| -- return True; |
| -- end Func_Id; |
| |
| -- Assume that the record type lacks eligible components, discriminants, |
| -- and variant parts. |
| |
| Stmts := No_List; |
| |
| -- Validate the discriminants |
| |
| if not Is_Unchecked_Union (Rec_Typ) then |
| Validate_Fields |
| (Obj_Id => Obj_Id, |
| Fields => Discriminant_Specifications (Typ_Decl), |
| Stmts => Stmts); |
| end if; |
| |
| -- Validate the components and variant parts |
| |
| Validate_Component_List |
| (Obj_Id => Obj_Id, |
| Comp_List => Comps, |
| Stmts => Stmts); |
| |
| -- Generate: |
| -- return True; |
| |
| Append_New_To (Stmts, |
| Make_Simple_Return_Statement (Loc, |
| Expression => New_Occurrence_Of (Standard_True, Loc))); |
| |
| -- Generate: |
| -- function Func_Id (Obj_Id : Formal_Typ) return Boolean is |
| -- begin |
| -- Stmts |
| -- end Func_Id; |
| |
| Mutate_Ekind (Func_Id, E_Function); |
| Set_Is_Internal (Func_Id); |
| Set_Is_Pure (Func_Id); |
| |
| if not Debug_Generated_Code then |
| Set_Debug_Info_Off (Func_Id); |
| end if; |
| |
| Insert_Action (Attr, |
| Make_Subprogram_Body (Loc, |
| Specification => |
| Make_Function_Specification (Loc, |
| Defining_Unit_Name => Func_Id, |
| Parameter_Specifications => New_List ( |
| Make_Parameter_Specification (Loc, |
| Defining_Identifier => Obj_Id, |
| Parameter_Type => New_Occurrence_Of (Formal_Typ, Loc))), |
| Result_Definition => |
| New_Occurrence_Of (Standard_Boolean, Loc)), |
| Declarations => New_List, |
| Handled_Statement_Sequence => |
| Make_Handled_Sequence_Of_Statements (Loc, |
| Statements => Stmts)), |
| Suppress => Discriminant_Check); |
| |
| return Func_Id; |
| end Build_Record_VS_Func; |
| |
| ---------------------------------- |
| -- Compile_Stream_Body_In_Scope -- |
| ---------------------------------- |
| |
| procedure Compile_Stream_Body_In_Scope |
| (N : Node_Id; |
| Decl : Node_Id; |
| Arr : Entity_Id) |
| is |
| C_Type : constant Entity_Id := Base_Type (Component_Type (Arr)); |
| Curr : constant Entity_Id := Current_Scope; |
| Install : Boolean := False; |
| Scop : Entity_Id := Scope (Arr); |
| |
| begin |
| if Is_Hidden (Arr) |
| and then not In_Open_Scopes (Scop) |
| and then Ekind (Scop) = E_Package |
| then |
| Install := True; |
| |
| else |
| -- The component type may be private, in which case we install its |
| -- full view to compile the subprogram. |
| |
| -- The component type may be private, in which case we install its |
| -- full view to compile the subprogram. We do not do this if the |
| -- type has a Stream_Convert pragma, which indicates that there are |
| -- special stream-processing operations for that type (for example |
| -- Unbounded_String and its wide varieties). |
| |
| Scop := Scope (C_Type); |
| |
| if Is_Private_Type (C_Type) |
| and then Present (Full_View (C_Type)) |
| and then not In_Open_Scopes (Scop) |
| and then Ekind (Scop) = E_Package |
| and then No (Get_Stream_Convert_Pragma (C_Type)) |
| then |
| Install := True; |
| end if; |
| end if; |
| |
| -- If we are within an instance body, then all visibility has been |
| -- established already and there is no need to install the package. |
| |
| if Install and then not In_Instance_Body then |
| Push_Scope (Scop); |
| Install_Visible_Declarations (Scop); |
| Install_Private_Declarations (Scop); |
| |
| -- The entities in the package are now visible, but the generated |
| -- stream entity must appear in the current scope (usually an |
| -- enclosing stream function) so that itypes all have their proper |
| -- scopes. |
| |
| Push_Scope (Curr); |
| else |
| Install := False; |
| end if; |
| |
| Insert_Action (N, Decl); |
| |
| if Install then |
| |
| -- Remove extra copy of current scope, and package itself |
| |
| Pop_Scope; |
| End_Package_Scope (Scop); |
| end if; |
| end Compile_Stream_Body_In_Scope; |
| |
| ----------------------------------- |
| -- Default_Streaming_Unavailable -- |
| ----------------------------------- |
| |
| function Default_Streaming_Unavailable (Typ : Entity_Id) return Boolean is |
| Btyp : constant Entity_Id := Implementation_Base_Type (Typ); |
| begin |
| if Is_Immutably_Limited_Type (Btyp) |
| and then not Is_Tagged_Type (Btyp) |
| and then not (Ekind (Btyp) = E_Record_Type |
| and then Present (Corresponding_Concurrent_Type (Btyp))) |
| then |
| pragma Assert (In_Instance_Body); |
| return True; |
| end if; |
| return False; |
| end Default_Streaming_Unavailable; |
| |
| ----------------------------------- |
| -- Expand_Access_To_Protected_Op -- |
| ----------------------------------- |
| |
| procedure Expand_Access_To_Protected_Op |
| (N : Node_Id; |
| Pref : Node_Id; |
| Typ : Entity_Id) |
| is |
| -- The value of the attribute_reference is a record containing two |
| -- fields: an access to the protected object, and an access to the |
| -- subprogram itself. The prefix is an identifier or a selected |
| -- component. |
| |
| function Has_By_Protected_Procedure_Prefixed_View return Boolean; |
| -- Determine whether Pref denotes the prefixed class-wide interface |
| -- view of a procedure with synchronization kind By_Protected_Procedure. |
| |
| ---------------------------------------------- |
| -- Has_By_Protected_Procedure_Prefixed_View -- |
| ---------------------------------------------- |
| |
| function Has_By_Protected_Procedure_Prefixed_View return Boolean is |
| begin |
| return Nkind (Pref) = N_Selected_Component |
| and then Nkind (Prefix (Pref)) in N_Has_Entity |
| and then Present (Entity (Prefix (Pref))) |
| and then Is_Class_Wide_Type (Etype (Entity (Prefix (Pref)))) |
| and then (Is_Synchronized_Interface (Etype (Entity (Prefix (Pref)))) |
| or else |
| Is_Protected_Interface (Etype (Entity (Prefix (Pref))))) |
| and then Is_By_Protected_Procedure (Entity (Selector_Name (Pref))); |
| end Has_By_Protected_Procedure_Prefixed_View; |
| |
| -- Local variables |
| |
| Loc : constant Source_Ptr := Sloc (N); |
| Agg : Node_Id; |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Sub : Entity_Id := Empty; |
| Sub_Ref : Node_Id; |
| E_T : constant Entity_Id := Equivalent_Type (Btyp); |
| Acc : constant Entity_Id := |
| Etype (Next_Component (First_Component (E_T))); |
| Obj_Ref : Node_Id; |
| Curr : Entity_Id; |
| |
| -- Start of processing for Expand_Access_To_Protected_Op |
| |
| begin |
| -- Within the body of the protected type, the prefix designates a local |
| -- operation, and the object is the first parameter of the corresponding |
| -- protected body of the current enclosing operation. |
| |
| if Is_Entity_Name (Pref) then |
| -- All indirect calls are external calls, so must do locking and |
| -- barrier reevaluation, even if the 'Access occurs within the |
| -- protected body. Hence the call to External_Subprogram, as opposed |
| -- to Protected_Body_Subprogram, below. See RM-9.5(5). This means |
| -- that indirect calls from within the same protected body will |
| -- deadlock, as allowed by RM-9.5.1(8,15,17). |
| |
| Sub := New_Occurrence_Of (External_Subprogram (Entity (Pref)), Loc); |
| |
| -- Don't traverse the scopes when the attribute occurs within an init |
| -- proc, because we directly use the _init formal of the init proc in |
| -- that case. |
| |
| Curr := Current_Scope; |
| if not Is_Init_Proc (Curr) then |
| pragma Assert (In_Open_Scopes (Scope (Entity (Pref)))); |
| |
| while Scope (Curr) /= Scope (Entity (Pref)) loop |
| Curr := Scope (Curr); |
| end loop; |
| end if; |
| |
| -- In case of protected entries the first formal of its Protected_ |
| -- Body_Subprogram is the address of the object. |
| |
| if Ekind (Curr) = E_Entry then |
| Obj_Ref := |
| New_Occurrence_Of |
| (First_Formal |
| (Protected_Body_Subprogram (Curr)), Loc); |
| |
| -- If the current scope is an init proc, then use the address of the |
| -- _init formal as the object reference. |
| |
| elsif Is_Init_Proc (Curr) then |
| Obj_Ref := |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Occurrence_Of (First_Formal (Curr), Loc), |
| Attribute_Name => Name_Address); |
| |
| -- In case of protected subprograms the first formal of its |
| -- Protected_Body_Subprogram is the object and we get its address. |
| |
| else |
| Obj_Ref := |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| New_Occurrence_Of |
| (First_Formal |
| (Protected_Body_Subprogram (Curr)), Loc), |
| Attribute_Name => Name_Address); |
| end if; |
| |
| elsif Has_By_Protected_Procedure_Prefixed_View then |
| Obj_Ref := |
| Make_Attribute_Reference (Loc, |
| Prefix => Relocate_Node (Prefix (Pref)), |
| Attribute_Name => Name_Address); |
| |
| -- Analyze the object address with expansion disabled. Required |
| -- because its expansion would displace the pointer to the object, |
| -- which is not correct at this stage since the object type is a |
| -- class-wide interface type and we are dispatching a call to a |
| -- thunk (which would erroneously displace the pointer again). |
| |
| Expander_Mode_Save_And_Set (False); |
| Analyze (Obj_Ref); |
| Set_Analyzed (Obj_Ref); |
| Expander_Mode_Restore; |
| |
| -- Case where the prefix is not an entity name. Find the |
| -- version of the protected operation to be called from |
| -- outside the protected object. |
| |
| else |
| Sub := |
| New_Occurrence_Of |
| (External_Subprogram |
| (Entity (Selector_Name (Pref))), Loc); |
| |
| Obj_Ref := |
| Make_Attribute_Reference (Loc, |
| Prefix => Relocate_Node (Prefix (Pref)), |
| Attribute_Name => Name_Address); |
| end if; |
| |
| if Has_By_Protected_Procedure_Prefixed_View then |
| declare |
| Ctrl_Tag : Node_Id := Duplicate_Subexpr (Prefix (Pref)); |
| Prim_Addr : Node_Id; |
| Subp : constant Entity_Id := Entity (Selector_Name (Pref)); |
| Typ : constant Entity_Id := |
| Etype (Etype (Entity (Prefix (Pref)))); |
| begin |
| -- The target subprogram is a thunk; retrieve its address from |
| -- its secondary dispatch table slot. |
| |
| Build_Get_Prim_Op_Address (Loc, |
| Typ => Typ, |
| Tag_Node => Ctrl_Tag, |
| Position => DT_Position (Subp), |
| New_Node => Prim_Addr); |
| |
| -- Mark the access to the target subprogram as an access to the |
| -- dispatch table and perform an unchecked type conversion to such |
| -- access type. This is required to allow the backend to properly |
| -- identify and handle the access to the dispatch table slot on |
| -- targets where the dispatch table contains descriptors (instead |
| -- of pointers). |
| |
| Set_Is_Dispatch_Table_Entity (Acc); |
| Sub_Ref := Unchecked_Convert_To (Acc, Prim_Addr); |
| Analyze (Sub_Ref); |
| |
| Agg := |
| Make_Aggregate (Loc, |
| Expressions => New_List (Obj_Ref, Sub_Ref)); |
| end; |
| |
| -- Common case |
| |
| else |
| Sub_Ref := |
| Make_Attribute_Reference (Loc, |
| Prefix => Sub, |
| Attribute_Name => Name_Access); |
| |
| -- We set the type of the access reference to the already generated |
| -- access_to_subprogram type, and declare the reference analyzed, |
| -- to prevent further expansion when the enclosing aggregate is |
| -- analyzed. |
| |
| Set_Etype (Sub_Ref, Acc); |
| Set_Analyzed (Sub_Ref); |
| |
| Agg := |
| Make_Aggregate (Loc, |
| Expressions => New_List (Obj_Ref, Sub_Ref)); |
| |
| -- Sub_Ref has been marked as analyzed, but we still need to make |
| -- sure Sub is correctly frozen. |
| |
| Freeze_Before (N, Entity (Sub)); |
| end if; |
| |
| Rewrite (N, Agg); |
| Analyze_And_Resolve (N, E_T); |
| |
| -- For subsequent analysis, the node must retain its type. The backend |
| -- will replace it with the equivalent type where needed. |
| |
| Set_Etype (N, Typ); |
| end Expand_Access_To_Protected_Op; |
| |
| -------------------------- |
| -- Expand_Fpt_Attribute -- |
| -------------------------- |
| |
| procedure Expand_Fpt_Attribute |
| (N : Node_Id; |
| Pkg : RE_Id; |
| Nam : Name_Id; |
| Args : List_Id) |
| is |
| Loc : constant Source_Ptr := Sloc (N); |
| Typ : constant Entity_Id := Etype (N); |
| Fnm : Node_Id; |
| |
| begin |
| -- The function name is the selected component Attr_xxx.yyy where |
| -- Attr_xxx is the package name, and yyy is the argument Nam. |
| |
| -- Note: it would be more usual to have separate RE entries for each |
| -- of the entities in the Fat packages, but first they have identical |
| -- names (so we would have to have lots of renaming declarations to |
| -- meet the normal RE rule of separate names for all runtime entities), |
| -- and second there would be an awful lot of them. |
| |
| Fnm := |
| Make_Selected_Component (Loc, |
| Prefix => New_Occurrence_Of (RTE (Pkg), Loc), |
| Selector_Name => Make_Identifier (Loc, Nam)); |
| |
| -- The generated call is given the provided set of parameters, and then |
| -- wrapped in a conversion which converts the result to the target type. |
| |
| Rewrite (N, |
| Convert_To (Typ, |
| Make_Function_Call (Loc, |
| Name => Fnm, |
| Parameter_Associations => Args))); |
| |
| Analyze_And_Resolve (N, Typ); |
| end Expand_Fpt_Attribute; |
| |
| ---------------------------- |
| -- Expand_Fpt_Attribute_R -- |
| ---------------------------- |
| |
| -- The single argument is converted to its root type to call the |
| -- appropriate runtime function, with the actual call being built |
| -- by Expand_Fpt_Attribute |
| |
| procedure Expand_Fpt_Attribute_R (N : Node_Id) is |
| E1 : constant Node_Id := First (Expressions (N)); |
| Ftp : Entity_Id; |
| Pkg : RE_Id; |
| begin |
| Find_Fat_Info (Etype (E1), Ftp, Pkg); |
| Expand_Fpt_Attribute |
| (N, Pkg, Attribute_Name (N), |
| New_List (Unchecked_Convert_To (Ftp, Relocate_Node (E1)))); |
| end Expand_Fpt_Attribute_R; |
| |
| ----------------------------- |
| -- Expand_Fpt_Attribute_RI -- |
| ----------------------------- |
| |
| -- The first argument is converted to its root type and the second |
| -- argument is converted to standard long long integer to call the |
| -- appropriate runtime function, with the actual call being built |
| -- by Expand_Fpt_Attribute |
| |
| procedure Expand_Fpt_Attribute_RI (N : Node_Id) is |
| E1 : constant Node_Id := First (Expressions (N)); |
| E2 : constant Node_Id := Next (E1); |
| Ftp : Entity_Id; |
| Pkg : RE_Id; |
| begin |
| Find_Fat_Info (Etype (E1), Ftp, Pkg); |
| Expand_Fpt_Attribute |
| (N, Pkg, Attribute_Name (N), |
| New_List ( |
| Unchecked_Convert_To (Ftp, Relocate_Node (E1)), |
| Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2)))); |
| end Expand_Fpt_Attribute_RI; |
| |
| ----------------------------- |
| -- Expand_Fpt_Attribute_RR -- |
| ----------------------------- |
| |
| -- The two arguments are converted to their root types to call the |
| -- appropriate runtime function, with the actual call being built |
| -- by Expand_Fpt_Attribute |
| |
| procedure Expand_Fpt_Attribute_RR (N : Node_Id) is |
| E1 : constant Node_Id := First (Expressions (N)); |
| E2 : constant Node_Id := Next (E1); |
| Ftp : Entity_Id; |
| Pkg : RE_Id; |
| |
| begin |
| Find_Fat_Info (Etype (E1), Ftp, Pkg); |
| Expand_Fpt_Attribute |
| (N, Pkg, Attribute_Name (N), |
| New_List ( |
| Unchecked_Convert_To (Ftp, Relocate_Node (E1)), |
| Unchecked_Convert_To (Ftp, Relocate_Node (E2)))); |
| end Expand_Fpt_Attribute_RR; |
| |
| --------------------------------- |
| -- Expand_Loop_Entry_Attribute -- |
| --------------------------------- |
| |
| procedure Expand_Loop_Entry_Attribute (N : Node_Id) is |
| procedure Build_Conditional_Block |
| (Loc : Source_Ptr; |
| Cond : Node_Id; |
| Loop_Stmt : Node_Id; |
| If_Stmt : out Node_Id; |
| Blk_Stmt : out Node_Id); |
| -- Create a block Blk_Stmt with an empty declarative list and a single |
| -- loop Loop_Stmt. The block is encased in an if statement If_Stmt with |
| -- condition Cond. If_Stmt is Empty when there is no condition provided. |
| |
| function Is_Array_Iteration (N : Node_Id) return Boolean; |
| -- Determine whether loop statement N denotes an Ada 2012 iteration over |
| -- an array object. |
| |
| ----------------------------- |
| -- Build_Conditional_Block -- |
| ----------------------------- |
| |
| procedure Build_Conditional_Block |
| (Loc : Source_Ptr; |
| Cond : Node_Id; |
| Loop_Stmt : Node_Id; |
| If_Stmt : out Node_Id; |
| Blk_Stmt : out Node_Id) |
| is |
| begin |
| -- Do not reanalyze the original loop statement because it is simply |
| -- being relocated. |
| |
| Set_Analyzed (Loop_Stmt); |
| |
| Blk_Stmt := |
| Make_Block_Statement (Loc, |
| Declarations => New_List, |
| Handled_Statement_Sequence => |
| Make_Handled_Sequence_Of_Statements (Loc, |
| Statements => New_List (Loop_Stmt))); |
| |
| if Present (Cond) then |
| If_Stmt := |
| Make_If_Statement (Loc, |
| Condition => Cond, |
| Then_Statements => New_List (Blk_Stmt)); |
| else |
| If_Stmt := Empty; |
| end if; |
| end Build_Conditional_Block; |
| |
| ------------------------ |
| -- Is_Array_Iteration -- |
| ------------------------ |
| |
| function Is_Array_Iteration (N : Node_Id) return Boolean is |
| Stmt : constant Node_Id := Original_Node (N); |
| Iter : Node_Id; |
| |
| begin |
| if Nkind (Stmt) = N_Loop_Statement |
| and then Present (Iteration_Scheme (Stmt)) |
| and then Present (Iterator_Specification (Iteration_Scheme (Stmt))) |
| then |
| Iter := Iterator_Specification (Iteration_Scheme (Stmt)); |
| |
| return |
| Of_Present (Iter) and then Is_Array_Type (Etype (Name (Iter))); |
| end if; |
| |
| return False; |
| end Is_Array_Iteration; |
| |
| -- Local variables |
| |
| Pref : constant Node_Id := Prefix (N); |
| Base_Typ : constant Entity_Id := Base_Type (Etype (Pref)); |
| Exprs : constant List_Id := Expressions (N); |
| Aux_Decl : Node_Id; |
| Blk : Node_Id := Empty; |
| Decls : List_Id; |
| Installed : Boolean; |
| Loc : Source_Ptr; |
| Loop_Id : Entity_Id; |
| Loop_Stmt : Node_Id; |
| Result : Node_Id := Empty; |
| Scheme : Node_Id; |
| Temp_Decl : Node_Id; |
| Temp_Id : Entity_Id; |
| |
| -- Start of processing for Expand_Loop_Entry_Attribute |
| |
| begin |
| -- Step 1: Find the related loop |
| |
| -- The loop label variant of attribute 'Loop_Entry already has all the |
| -- information in its expression. |
| |
| if Present (Exprs) then |
| Loop_Id := Entity (First (Exprs)); |
| Loop_Stmt := Label_Construct (Parent (Loop_Id)); |
| |
| -- Climb the parent chain to find the nearest enclosing loop. Skip |
| -- all internally generated loops for quantified expressions and for |
| -- element iterators over multidimensional arrays because the pragma |
| -- applies to source loop. |
| |
| else |
| Loop_Stmt := N; |
| while Present (Loop_Stmt) loop |
| if Nkind (Loop_Stmt) = N_Loop_Statement |
| and then Nkind (Original_Node (Loop_Stmt)) = N_Loop_Statement |
| and then Comes_From_Source (Original_Node (Loop_Stmt)) |
| then |
| exit; |
| end if; |
| |
| Loop_Stmt := Parent (Loop_Stmt); |
| end loop; |
| |
| Loop_Id := Entity (Identifier (Loop_Stmt)); |
| end if; |
| |
| Loc := Sloc (Loop_Stmt); |
| |
| -- Step 2: Transform the loop |
| |
| -- The loop has already been transformed during the expansion of a prior |
| -- 'Loop_Entry attribute. Retrieve the declarative list of the block. |
| |
| if Has_Loop_Entry_Attributes (Loop_Id) then |
| |
| -- When the related loop name appears as the argument of attribute |
| -- Loop_Entry, the corresponding label construct is the generated |
| -- block statement. This is because the expander reuses the label. |
| |
| if Nkind (Loop_Stmt) = N_Block_Statement then |
| Decls := Declarations (Loop_Stmt); |
| |
| -- In all other cases, the loop must appear in the handled sequence |
| -- of statements of the generated block. |
| |
| else |
| pragma Assert |
| (Nkind (Parent (Loop_Stmt)) = N_Handled_Sequence_Of_Statements |
| and then |
| Nkind (Parent (Parent (Loop_Stmt))) = N_Block_Statement); |
| |
| Decls := Declarations (Parent (Parent (Loop_Stmt))); |
| end if; |
| |
| -- Transform the loop into a conditional block |
| |
| else |
| Set_Has_Loop_Entry_Attributes (Loop_Id); |
| Scheme := Iteration_Scheme (Loop_Stmt); |
| |
| -- Infinite loops are transformed into: |
| |
| -- declare |
| -- Temp1 : constant <type of Pref1> := <Pref1>; |
| -- . . . |
| -- TempN : constant <type of PrefN> := <PrefN>; |
| -- begin |
| -- loop |
| -- <original source statements with attribute rewrites> |
| -- end loop; |
| -- end; |
| |
| if No (Scheme) then |
| Build_Conditional_Block (Loc, |
| Cond => Empty, |
| Loop_Stmt => Relocate_Node (Loop_Stmt), |
| If_Stmt => Result, |
| Blk_Stmt => Blk); |
| |
| Result := Blk; |
| |
| -- While loops are transformed into: |
| |
| -- function Fnn return Boolean is |
| -- begin |
| -- <condition actions> |
| -- return <condition>; |
| -- end Fnn; |
| |
| -- if Fnn then |
| -- declare |
| -- Temp1 : constant <type of Pref1> := <Pref1>; |
| -- . . . |
| -- TempN : constant <type of PrefN> := <PrefN>; |
| -- begin |
| -- loop |
| -- <original source statements with attribute rewrites> |
| -- exit when not Fnn; |
| -- end loop; |
| -- end; |
| -- end if; |
| |
| -- Note that loops over iterators and containers are already |
| -- converted into while loops. |
| |
| elsif Present (Condition (Scheme)) then |
| declare |
| Func_Decl : Node_Id; |
| Func_Id : Entity_Id; |
| Stmts : List_Id; |
| |
| begin |
| Func_Id := Make_Temporary (Loc, 'F'); |
| |
| -- Wrap the condition of the while loop in a Boolean function. |
| -- This avoids the duplication of the same code which may lead |
| -- to gigi issues with respect to multiple declaration of the |
| -- same entity in the presence of side effects or checks. Note |
| -- that the condition actions must also be relocated into the |
| -- wrapping function because they may contain itypes, e.g. in |
| -- the case of a comparison involving slices. |
| |
| -- Generate: |
| -- <condition actions> |
| -- return <condition>; |
| |
| if Present (Condition_Actions (Scheme)) then |
| Stmts := Condition_Actions (Scheme); |
| else |
| Stmts := New_List; |
| end if; |
| |
| Append_To (Stmts, |
| Make_Simple_Return_Statement (Loc, |
| Expression => |
| New_Copy_Tree (Condition (Scheme), |
| New_Scope => Func_Id))); |
| |
| -- Generate: |
| -- function Fnn return Boolean is |
| -- begin |
| -- <Stmts> |
| -- end Fnn; |
| |
| Func_Decl := |
| Make_Subprogram_Body (Loc, |
| Specification => |
| Make_Function_Specification (Loc, |
| Defining_Unit_Name => Func_Id, |
| Result_Definition => |
| New_Occurrence_Of (Standard_Boolean, Loc)), |
| Declarations => Empty_List, |
| Handled_Statement_Sequence => |
| Make_Handled_Sequence_Of_Statements (Loc, |
| Statements => Stmts)); |
| |
| -- The function is inserted before the related loop. Make sure |
| -- to analyze it in the context of the loop's enclosing scope. |
| |
| Push_Scope (Scope (Loop_Id)); |
| Insert_Action (Loop_Stmt, Func_Decl); |
| Pop_Scope; |
| |
| -- The analysis of the condition may have generated entities |
| -- (such as itypes) that are now used within the function. |
| -- Adjust their scopes accordingly so that their use appears |
| -- in their scope of definition. |
| |
| declare |
| Ent : Entity_Id; |
| |
| begin |
| Ent := First_Entity (Loop_Id); |
| |
| while Present (Ent) loop |
| -- Various entities that now occur within the function |
| -- need to have their scope reset, but not all entities |
| -- associated with Loop_Id are now inside the function. |
| -- The function entity itself and loop parameters can |
| -- be outside the function, and there may be others. |
| -- It's not clear how the determination of what entity |
| -- scopes need to be adjusted can be made accurately. |
| -- Perhaps it will be necessary to traverse the function |
| -- body to find the exact entities whose scopes need to |
| -- be reset to the function's Entity_Id. ??? |
| |
| if Ekind (Ent) /= E_Loop_Parameter |
| and then Ent /= Func_Id |
| then |
| Set_Scope (Ent, Func_Id); |
| end if; |
| |
| Next_Entity (Ent); |
| end loop; |
| end; |
| |
| -- Transform the original while loop into an infinite loop |
| -- where the last statement checks the negated condition. This |
| -- placement ensures that the condition will not be evaluated |
| -- twice on the first iteration. |
| |
| Set_Iteration_Scheme (Loop_Stmt, Empty); |
| Scheme := Empty; |
| |
| -- Generate: |
| -- exit when not Fnn; |
| |
| Append_To (Statements (Loop_Stmt), |
| Make_Exit_Statement (Loc, |
| Condition => |
| Make_Op_Not (Loc, |
| Right_Opnd => |
| Make_Function_Call (Loc, |
| Name => New_Occurrence_Of (Func_Id, Loc))))); |
| |
| Build_Conditional_Block (Loc, |
| Cond => |
| Make_Function_Call (Loc, |
| Name => New_Occurrence_Of (Func_Id, Loc)), |
| Loop_Stmt => Relocate_Node (Loop_Stmt), |
| If_Stmt => Result, |
| Blk_Stmt => Blk); |
| end; |
| |
| -- Ada 2012 iteration over an array is transformed into: |
| |
| -- if <Array_Nam>'Length (1) > 0 |
| -- and then <Array_Nam>'Length (N) > 0 |
| -- then |
| -- declare |
| -- Temp1 : constant <type of Pref1> := <Pref1>; |
| -- . . . |
| -- TempN : constant <type of PrefN> := <PrefN>; |
| -- begin |
| -- for X in ... loop -- multiple loops depending on dims |
| -- <original source statements with attribute rewrites> |
| -- end loop; |
| -- end; |
| -- end if; |
| |
| elsif Is_Array_Iteration (Loop_Stmt) then |
| declare |
| Array_Nam : constant Entity_Id := |
| Entity (Name (Iterator_Specification |
| (Iteration_Scheme (Original_Node (Loop_Stmt))))); |
| Num_Dims : constant Pos := |
| Number_Dimensions (Etype (Array_Nam)); |
| Cond : Node_Id := Empty; |
| Check : Node_Id; |
| |
| begin |
| -- Generate a check which determines whether all dimensions of |
| -- the array are non-null. |
| |
| for Dim in 1 .. Num_Dims loop |
| Check := |
| Make_Op_Gt (Loc, |
| Left_Opnd => |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Occurrence_Of (Array_Nam, Loc), |
| Attribute_Name => Name_Length, |
| Expressions => New_List ( |
| Make_Integer_Literal (Loc, Dim))), |
| Right_Opnd => |
| Make_Integer_Literal (Loc, 0)); |
| |
| if No (Cond) then |
| Cond := Check; |
| else |
| Cond := |
| Make_And_Then (Loc, |
| Left_Opnd => Cond, |
| Right_Opnd => Check); |
| end if; |
| end loop; |
| |
| Build_Conditional_Block (Loc, |
| Cond => Cond, |
| Loop_Stmt => Relocate_Node (Loop_Stmt), |
| If_Stmt => Result, |
| Blk_Stmt => Blk); |
| end; |
| |
| -- For loops are transformed into: |
| |
| -- if <Low> <= <High> then |
| -- declare |
| -- Temp1 : constant <type of Pref1> := <Pref1>; |
| -- . . . |
| -- TempN : constant <type of PrefN> := <PrefN>; |
| -- begin |
| -- for <Def_Id> in <Low> .. <High> loop |
| -- <original source statements with attribute rewrites> |
| -- end loop; |
| -- end; |
| -- end if; |
| |
| elsif Present (Loop_Parameter_Specification (Scheme)) then |
| declare |
| Loop_Spec : constant Node_Id := |
| Loop_Parameter_Specification (Scheme); |
| Cond : Node_Id; |
| Subt_Def : Node_Id; |
| |
| begin |
| Subt_Def := Discrete_Subtype_Definition (Loop_Spec); |
| |
| -- When the loop iterates over a subtype indication with a |
| -- range, use the low and high bounds of the subtype itself. |
| |
| if Nkind (Subt_Def) = N_Subtype_Indication then |
| Subt_Def := Scalar_Range (Etype (Subt_Def)); |
| end if; |
| |
| pragma Assert (Nkind (Subt_Def) = N_Range); |
| |
| -- Generate |
| -- Low <= High |
| |
| Cond := |
| Make_Op_Le (Loc, |
| Left_Opnd => New_Copy_Tree (Low_Bound (Subt_Def)), |
| Right_Opnd => New_Copy_Tree (High_Bound (Subt_Def))); |
| |
| Build_Conditional_Block (Loc, |
| Cond => Cond, |
| Loop_Stmt => Relocate_Node (Loop_Stmt), |
| If_Stmt => Result, |
| Blk_Stmt => Blk); |
| end; |
| end if; |
| |
| Decls := Declarations (Blk); |
| end if; |
| |
| -- Step 3: Create a constant to capture the value of the prefix at the |
| -- entry point into the loop. |
| |
| Temp_Id := Make_Temporary (Loc, 'P'); |
| |
| -- Preserve the tag of the prefix by offering a specific view of the |
| -- class-wide version of the prefix. |
| |
| if Is_Tagged_Type (Base_Typ) then |
| Tagged_Case : declare |
| CW_Temp : Entity_Id; |
| CW_Typ : Entity_Id; |
| |
| begin |
| -- Generate: |
| -- CW_Temp : constant Base_Typ'Class := Base_Typ'Class (Pref); |
| |
| CW_Temp := Make_Temporary (Loc, 'T'); |
| CW_Typ := Class_Wide_Type (Base_Typ); |
| |
| Aux_Decl := |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => CW_Temp, |
| Constant_Present => True, |
| Object_Definition => New_Occurrence_Of (CW_Typ, Loc), |
| Expression => |
| Convert_To (CW_Typ, Relocate_Node (Pref))); |
| Append_To (Decls, Aux_Decl); |
| |
| -- Generate: |
| -- Temp : Base_Typ renames Base_Typ (CW_Temp); |
| |
| Temp_Decl := |
| Make_Object_Renaming_Declaration (Loc, |
| Defining_Identifier => Temp_Id, |
| Subtype_Mark => New_Occurrence_Of (Base_Typ, Loc), |
| Name => |
| Convert_To (Base_Typ, New_Occurrence_Of (CW_Temp, Loc))); |
| Append_To (Decls, Temp_Decl); |
| end Tagged_Case; |
| |
| -- Untagged case |
| |
| else |
| Untagged_Case : declare |
| Temp_Expr : Node_Id; |
| |
| begin |
| Aux_Decl := Empty; |
| |
| -- Generate a nominal type for the constant when the prefix is of |
| -- a constrained type. This is achieved by setting the Etype of |
| -- the relocated prefix to its base type. Since the prefix is now |
| -- the initialization expression of the constant, its freezing |
| -- will produce a proper nominal type. |
| |
| Temp_Expr := Relocate_Node (Pref); |
| Set_Etype (Temp_Expr, Base_Typ); |
| |
| -- Generate: |
| -- Temp : constant Base_Typ := Pref; |
| |
| Temp_Decl := |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Temp_Id, |
| Constant_Present => True, |
| Object_Definition => New_Occurrence_Of (Base_Typ, Loc), |
| Expression => Temp_Expr); |
| Append_To (Decls, Temp_Decl); |
| end Untagged_Case; |
| end if; |
| |
| -- Step 4: Analyze all bits |
| |
| Installed := Current_Scope = Scope (Loop_Id); |
| |
| -- Depending on the pracement of attribute 'Loop_Entry relative to the |
| -- associated loop, ensure the proper visibility for analysis. |
| |
| if not Installed then |
| Push_Scope (Scope (Loop_Id)); |
| end if; |
| |
| -- The analysis of the conditional block takes care of the constant |
| -- declaration. |
| |
| if Present (Result) then |
| Rewrite (Loop_Stmt, Result); |
| Analyze (Loop_Stmt); |
| |
| -- The conditional block was analyzed when a previous 'Loop_Entry was |
| -- expanded. There is no point in reanalyzing the block, simply analyze |
| -- the declaration of the constant. |
| |
| else |
| if Present (Aux_Decl) then |
| Analyze (Aux_Decl); |
| end if; |
| |
| Analyze (Temp_Decl); |
| end if; |
| |
| Rewrite (N, New_Occurrence_Of (Temp_Id, Loc)); |
| Analyze (N); |
| |
| if not Installed then |
| Pop_Scope; |
| end if; |
| end Expand_Loop_Entry_Attribute; |
| |
| ------------------------------ |
| -- Expand_Min_Max_Attribute -- |
| ------------------------------ |
| |
| procedure Expand_Min_Max_Attribute (N : Node_Id) is |
| begin |
| -- Min and Max are handled by the back end (except that static cases |
| -- have already been evaluated during semantic processing, although the |
| -- back end should not count on this). The one bit of special processing |
| -- required in the normal case is that these two attributes typically |
| -- generate conditionals in the code, so check the relevant restriction. |
| |
| Check_Restriction (No_Implicit_Conditionals, N); |
| end Expand_Min_Max_Attribute; |
| |
| ---------------------------------- |
| -- Expand_N_Attribute_Reference -- |
| ---------------------------------- |
| |
| procedure Expand_N_Attribute_Reference (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Pref : constant Node_Id := Prefix (N); |
| Exprs : constant List_Id := Expressions (N); |
| |
| function Get_Integer_Type (Typ : Entity_Id) return Entity_Id; |
| -- Return a small integer type appropriate for the enumeration type |
| |
| procedure Rewrite_Attribute_Proc_Call (Pname : Entity_Id); |
| -- Rewrites an attribute for Read, Write, Output, or Put_Image with a |
| -- call to the appropriate TSS procedure. Pname is the entity for the |
| -- procedure to call. |
| |
| ---------------------- |
| -- Get_Integer_Type -- |
| ---------------------- |
| |
| function Get_Integer_Type (Typ : Entity_Id) return Entity_Id is |
| Siz : constant Uint := Esize (Base_Type (Typ)); |
| |
| begin |
| -- We need to accommodate invalid values of the base type since we |
| -- accept them for Enum_Rep and Pos, so we reason on the Esize. |
| |
| return Small_Integer_Type_For (Siz, Uns => Is_Unsigned_Type (Typ)); |
| end Get_Integer_Type; |
| |
| --------------------------------- |
| -- Rewrite_Attribute_Proc_Call -- |
| --------------------------------- |
| |
| procedure Rewrite_Attribute_Proc_Call (Pname : Entity_Id) is |
| Item : constant Node_Id := Next (First (Exprs)); |
| Item_Typ : constant Entity_Id := Etype (Item); |
| Formal : constant Entity_Id := Next_Formal (First_Formal (Pname)); |
| Formal_Typ : constant Entity_Id := Etype (Formal); |
| Is_Written : constant Boolean := Ekind (Formal) /= E_In_Parameter; |
| |
| begin |
| -- The expansion depends on Item, the second actual, which is |
| -- the object being streamed in or out. |
| |
| -- If the item is a component of a packed array type, and |
| -- a conversion is needed on exit, we introduce a temporary to |
| -- hold the value, because otherwise the packed reference will |
| -- not be properly expanded. |
| |
| if Nkind (Item) = N_Indexed_Component |
| and then Is_Packed (Base_Type (Etype (Prefix (Item)))) |
| and then Base_Type (Item_Typ) /= Base_Type (Formal_Typ) |
| and then Is_Written |
| then |
| declare |
| Temp : constant Entity_Id := Make_Temporary (Loc, 'V'); |
| Decl : Node_Id; |
| Assn : Node_Id; |
| |
| begin |
| Decl := |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Temp, |
| Object_Definition => New_Occurrence_Of (Formal_Typ, Loc)); |
| Set_Etype (Temp, Formal_Typ); |
| |
| Assn := |
| Make_Assignment_Statement (Loc, |
| Name => New_Copy_Tree (Item), |
| Expression => |
| Unchecked_Convert_To |
| (Item_Typ, New_Occurrence_Of (Temp, Loc))); |
| |
| Rewrite (Item, New_Occurrence_Of (Temp, Loc)); |
| Insert_Actions (N, |
| New_List ( |
| Decl, |
| Make_Procedure_Call_Statement (Loc, |
| Name => New_Occurrence_Of (Pname, Loc), |
| Parameter_Associations => Exprs), |
| Assn)); |
| |
| Rewrite (N, Make_Null_Statement (Loc)); |
| return; |
| end; |
| end if; |
| |
| -- For the class-wide dispatching cases, and for cases in which |
| -- the base type of the second argument matches the base type of |
| -- the corresponding formal parameter (that is to say the stream |
| -- operation is not inherited), we are all set, and can use the |
| -- argument unchanged. |
| |
| if not Is_Class_Wide_Type (Entity (Pref)) |
| and then not Is_Class_Wide_Type (Etype (Item)) |
| and then Base_Type (Item_Typ) /= Base_Type (Formal_Typ) |
| then |
| -- Perform a view conversion when either the argument or the |
| -- formal parameter are of a private type. |
| |
| if Is_Private_Type (Base_Type (Formal_Typ)) |
| or else Is_Private_Type (Base_Type (Item_Typ)) |
| then |
| Rewrite (Item, |
| Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item))); |
| |
| -- Otherwise perform a regular type conversion to ensure that all |
| -- relevant checks are installed. |
| |
| else |
| Rewrite (Item, Convert_To (Formal_Typ, Relocate_Node (Item))); |
| end if; |
| |
| -- For untagged derived types set Assignment_OK, to prevent |
| -- copies from being created when the unchecked conversion |
| -- is expanded (which would happen in Remove_Side_Effects |
| -- if Expand_N_Unchecked_Conversion were allowed to call |
| -- Force_Evaluation). The copy could violate Ada semantics in |
| -- cases such as an actual that is an out parameter. Note that |
| -- this approach is also used in exp_ch7 for calls to controlled |
| -- type operations to prevent problems with actuals wrapped in |
| -- unchecked conversions. |
| |
| if Is_Untagged_Derivation (Etype (Expression (Item))) then |
| Set_Assignment_OK (Item); |
| end if; |
| end if; |
| |
| -- The stream operation to call might be a renaming created by an |
| -- attribute definition clause, and might not be frozen yet. Ensure |
| -- that it has the necessary extra formals. |
| |
| if not Is_Frozen (Pname) then |
| Create_Extra_Formals (Pname); |
| end if; |
| |
| -- And now rewrite the call |
| |
| Rewrite (N, |
| Make_Procedure_Call_Statement (Loc, |
| Name => New_Occurrence_Of (Pname, Loc), |
| Parameter_Associations => Exprs)); |
| |
| Analyze (N); |
| end Rewrite_Attribute_Proc_Call; |
| |
| Typ : constant Entity_Id := Etype (N); |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Ptyp : constant Entity_Id := Etype (Pref); |
| Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N)); |
| |
| -- Start of processing for Expand_N_Attribute_Reference |
| |
| begin |
| -- Do required validity checking, if enabled. Do not apply check to |
| -- output parameters of an Asm instruction, since the value of this |
| -- is not set till after the attribute has been elaborated, and do |
| -- not apply the check to the arguments of a 'Read or 'Input attribute |
| -- reference since the scalar argument is an OUT scalar. |
| |
| if Validity_Checks_On and then Validity_Check_Operands |
| and then Id /= Attribute_Asm_Output |
| and then Id /= Attribute_Read |
| and then Id /= Attribute_Input |
| then |
| declare |
| Expr : Node_Id; |
| begin |
| Expr := First (Expressions (N)); |
| while Present (Expr) loop |
| Ensure_Valid (Expr); |
| Next (Expr); |
| end loop; |
| end; |
| end if; |
| |
| -- Ada 2005 (AI-318-02): If attribute prefix is a call to a build-in- |
| -- place function, then a temporary return object needs to be created |
| -- and access to it must be passed to the function. |
| |
| if Is_Build_In_Place_Function_Call (Pref) then |
| |
| -- If attribute is 'Old, the context is a postcondition, and |
| -- the temporary must go in the corresponding subprogram, not |
| -- the postcondition function or any created blocks, as when |
| -- the attribute appears in a quantified expression. This is |
| -- handled below in the expansion of the attribute. |
| |
| if Attribute_Name (Parent (Pref)) = Name_Old then |
| null; |
| else |
| Make_Build_In_Place_Call_In_Anonymous_Context (Pref); |
| end if; |
| |
| -- Ada 2005 (AI-318-02): Specialization of the previous case for prefix |
| -- containing build-in-place function calls whose returned object covers |
| -- interface types. |
| |
| elsif Present (Unqual_BIP_Iface_Function_Call (Pref)) then |
| Make_Build_In_Place_Iface_Call_In_Anonymous_Context (Pref); |
| end if; |
| |
| -- If prefix is a protected type name, this is a reference to the |
| -- current instance of the type. For a component definition, nothing |
| -- to do (expansion will occur in the init proc). In other contexts, |
| -- rewrite into reference to current instance. |
| |
| if Is_Protected_Self_Reference (Pref) |
| and then not |
| (Nkind (Parent (N)) in N_Index_Or_Discriminant_Constraint |
| | N_Discriminant_Association |
| and then Nkind (Parent (Parent (Parent (Parent (N))))) = |
| N_Component_Definition) |
| |
| -- No action needed for these attributes since the current instance |
| -- will be rewritten to be the name of the _object parameter |
| -- associated with the enclosing protected subprogram (see below). |
| |
| and then Id /= Attribute_Access |
| and then Id /= Attribute_Unchecked_Access |
| and then Id /= Attribute_Unrestricted_Access |
| then |
| Rewrite (Pref, Concurrent_Ref (Pref)); |
| Analyze (Pref); |
| end if; |
| |
| -- Remaining processing depends on specific attribute |
| |
| -- Note: individual sections of the following case statement are |
| -- allowed to assume there is no code after the case statement, and |
| -- are legitimately allowed to execute return statements if they have |
| -- nothing more to do. |
| |
| case Id is |
| |
| -- Attributes related to Ada 2012 iterators |
| |
| when Attribute_Constant_Indexing |
| | Attribute_Default_Iterator |
| | Attribute_Implicit_Dereference |
| | Attribute_Iterable |
| | Attribute_Iterator_Element |
| | Attribute_Variable_Indexing |
| => |
| null; |
| |
| -- Internal attributes used to deal with Ada 2012 delayed aspects. These |
| -- were already rejected by the parser. Thus they shouldn't appear here. |
| |
| when Internal_Attribute_Id => |
| raise Program_Error; |
| |
| ------------ |
| -- Access -- |
| ------------ |
| |
| when Attribute_Access |
| | Attribute_Unchecked_Access |
| | Attribute_Unrestricted_Access |
| => |
| Access_Cases : declare |
| Ref_Object : constant Node_Id := Get_Referenced_Object (Pref); |
| Btyp_DDT : Entity_Id; |
| |
| function Enclosing_Object (N : Node_Id) return Node_Id; |
| -- If N denotes a compound name (selected component, indexed |
| -- component, or slice), returns the name of the outermost such |
| -- enclosing object. Otherwise returns N. If the object is a |
| -- renaming, then the renamed object is returned. |
| |
| ---------------------- |
| -- Enclosing_Object -- |
| ---------------------- |
| |
| function Enclosing_Object (N : Node_Id) return Node_Id is |
| Obj_Name : Node_Id; |
| |
| begin |
| Obj_Name := N; |
| while Nkind (Obj_Name) in N_Selected_Component |
| | N_Indexed_Component |
| | N_Slice |
| loop |
| Obj_Name := Prefix (Obj_Name); |
| end loop; |
| |
| return Get_Referenced_Object (Obj_Name); |
| end Enclosing_Object; |
| |
| -- Local declarations |
| |
| Enc_Object : constant Node_Id := Enclosing_Object (Ref_Object); |
| |
| -- Start of processing for Access_Cases |
| |
| begin |
| Btyp_DDT := Designated_Type (Btyp); |
| |
| -- Handle designated types that come from the limited view |
| |
| if From_Limited_With (Btyp_DDT) |
| and then Has_Non_Limited_View (Btyp_DDT) |
| then |
| Btyp_DDT := Non_Limited_View (Btyp_DDT); |
| end if; |
| |
| -- In order to improve the text of error messages, the designated |
| -- type of access-to-subprogram itypes is set by the semantics as |
| -- the associated subprogram entity (see sem_attr). Now we replace |
| -- such node with the proper E_Subprogram_Type itype. |
| |
| if Id = Attribute_Unrestricted_Access |
| and then Is_Subprogram (Directly_Designated_Type (Typ)) |
| then |
| -- The following conditions ensure that this special management |
| -- is done only for "Address!(Prim'Unrestricted_Access)" nodes. |
| -- At this stage other cases in which the designated type is |
| -- still a subprogram (instead of an E_Subprogram_Type) are |
| -- wrong because the semantics must have overridden the type of |
| -- the node with the type imposed by the context. |
| |
| if Nkind (Parent (N)) = N_Unchecked_Type_Conversion |
| and then Is_RTE (Etype (Parent (N)), RE_Prim_Ptr) |
| then |
| Set_Etype (N, RTE (RE_Prim_Ptr)); |
| |
| else |
| declare |
| Subp : constant Entity_Id := |
| Directly_Designated_Type (Typ); |
| Etyp : Entity_Id; |
| Extra : Entity_Id := Empty; |
| New_Formal : Entity_Id; |
| Old_Formal : Entity_Id := First_Formal (Subp); |
| Subp_Typ : Entity_Id; |
| |
| begin |
| Subp_Typ := Create_Itype (E_Subprogram_Type, N); |
| Copy_Strub_Mode (Subp_Typ, Subp); |
| Set_Etype (Subp_Typ, Etype (Subp)); |
| Set_Returns_By_Ref (Subp_Typ, Returns_By_Ref (Subp)); |
| |
| if Present (Old_Formal) then |
| New_Formal := New_Copy (Old_Formal); |
| Set_First_Entity (Subp_Typ, New_Formal); |
| |
| loop |
| Set_Scope (New_Formal, Subp_Typ); |
| Etyp := Etype (New_Formal); |
| |
| -- Handle itypes. There is no need to duplicate |
| -- here the itypes associated with record types |
| -- (i.e the implicit full view of private types). |
| |
| if Is_Itype (Etyp) |
| and then Ekind (Base_Type (Etyp)) /= E_Record_Type |
| then |
| Extra := New_Copy (Etyp); |
| Set_Parent (Extra, New_Formal); |
| Set_Etype (New_Formal, Extra); |
| Set_Scope (Extra, Subp_Typ); |
| end if; |
| |
| Extra := New_Formal; |
| Next_Formal (Old_Formal); |
| exit when No (Old_Formal); |
| |
| Link_Entities (New_Formal, New_Copy (Old_Formal)); |
| Next_Entity (New_Formal); |
| end loop; |
| |
| Unlink_Next_Entity (New_Formal); |
| Set_Last_Entity (Subp_Typ, Extra); |
| end if; |
| |
| -- Now that the explicit formals have been duplicated, |
| -- any extra formals needed by the subprogram must be |
| -- created. |
| |
| if Present (Extra) then |
| Set_Extra_Formal (Extra, Empty); |
| end if; |
| |
| Create_Extra_Formals (Subp_Typ); |
| Set_Directly_Designated_Type (Typ, Subp_Typ); |
| end; |
| end if; |
| end if; |
| |
| if Is_Access_Protected_Subprogram_Type (Btyp) then |
| Expand_Access_To_Protected_Op (N, Pref, Typ); |
| |
| -- If prefix is a subprogram that has class-wide preconditions and |
| -- an indirect-call wrapper (ICW) of such subprogram is available |
| -- then replace the prefix by the ICW. |
| |
| elsif Is_Access_Subprogram_Type (Btyp) |
| and then Is_Entity_Name (Pref) |
| and then Present (Class_Preconditions (Entity (Pref))) |
| and then Present (Indirect_Call_Wrapper (Entity (Pref))) |
| then |
| Rewrite (Pref, |
| New_Occurrence_Of |
| (Indirect_Call_Wrapper (Entity (Pref)), Loc)); |
| Analyze_And_Resolve (N, Typ); |
| |
| -- If prefix is a type name, this is a reference to the current |
| -- instance of the type, within its initialization procedure. |
| |
| elsif Is_Entity_Name (Pref) |
| and then Is_Type (Entity (Pref)) |
| then |
| declare |
| Par : Node_Id; |
| Formal : Entity_Id; |
| |
| begin |
| -- If the current instance name denotes a task type, then |
| -- the access attribute is rewritten to be the name of the |
| -- "_task" parameter associated with the task type's task |
| -- procedure. An unchecked conversion is applied to ensure |
| -- a type match in cases of expander-generated calls (e.g. |
| -- init procs). |
| |
| if Is_Task_Type (Entity (Pref)) then |
| Formal := |
| First_Entity (Get_Task_Body_Procedure (Entity (Pref))); |
| while Present (Formal) loop |
| exit when Chars (Formal) = Name_uTask; |
| Next_Entity (Formal); |
| end loop; |
| |
| pragma Assert (Present (Formal)); |
| |
| Rewrite (N, |
| Unchecked_Convert_To (Typ, |
| New_Occurrence_Of (Formal, Loc))); |
| Set_Etype (N, Typ); |
| |
| elsif Is_Protected_Type (Entity (Pref)) then |
| |
| -- No action needed for current instance located in a |
| -- component definition (expansion will occur in the |
| -- init proc) |
| |
| if Is_Protected_Type (Current_Scope) then |
| null; |
| |
| -- If the current instance reference is located in a |
| -- protected subprogram or entry then rewrite the access |
| -- attribute to be the name of the "_object" parameter. |
| -- An unchecked conversion is applied to ensure a type |
| -- match in cases of expander-generated calls (e.g. init |
| -- procs). |
| |
| -- The code may be nested in a block, so find enclosing |
| -- scope that is a protected operation. |
| |
| else |
| declare |
| Subp : Entity_Id; |
| |
| begin |
| Subp := Current_Scope; |
| while Ekind (Subp) in E_Loop | E_Block loop |
| Subp := Scope (Subp); |
| end loop; |
| |
| Formal := |
| First_Entity |
| (Protected_Body_Subprogram (Subp)); |
| |
| -- For a protected subprogram the _Object parameter |
| -- is the protected record, so we create an access |
| -- to it. The _Object parameter of an entry is an |
| -- address. |
| |
| if Ekind (Subp) = E_Entry then |
| Rewrite (N, |
| Unchecked_Convert_To (Typ, |
| New_Occurrence_Of (Formal, Loc))); |
| Set_Etype (N, Typ); |
| |
| else |
| Rewrite (N, |
| Unchecked_Convert_To (Typ, |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Unrestricted_Access, |
| Prefix => |
| New_Occurrence_Of (Formal, Loc)))); |
| Analyze_And_Resolve (N); |
| end if; |
| end; |
| end if; |
| |
| -- The expression must appear in a default expression, |
| -- (which in the initialization procedure is the right-hand |
| -- side of an assignment), and not in a discriminant |
| -- constraint. |
| |
| else |
| Par := Parent (N); |
| while Present (Par) loop |
| exit when Nkind (Par) = N_Assignment_Statement; |
| |
| if Nkind (Par) = N_Component_Declaration then |
| return; |
| end if; |
| |
| Par := Parent (Par); |
| end loop; |
| |
| if Present (Par) then |
| Rewrite (N, |
| Make_Attribute_Reference (Loc, |
| Prefix => Make_Identifier (Loc, Name_uInit), |
| Attribute_Name => Attribute_Name (N))); |
| |
| Analyze_And_Resolve (N, Typ); |
| end if; |
| end if; |
| end; |
| |
| -- If the prefix of an Access attribute is a dereference of an |
| -- access parameter (or a renaming of such a dereference, or a |
| -- subcomponent of such a dereference) and the context is a |
| -- general access type (including the type of an object or |
| -- component with an access_definition, but not the anonymous |
| -- type of an access parameter or access discriminant), then |
| -- apply an accessibility check to the access parameter. We used |
| -- to rewrite the access parameter as a type conversion, but that |
| -- could only be done if the immediate prefix of the Access |
| -- attribute was the dereference, and didn't handle cases where |
| -- the attribute is applied to a subcomponent of the dereference, |
| -- since there's generally no available, appropriate access type |
| -- to convert to in that case. The attribute is passed as the |
| -- point to insert the check, because the access parameter may |
| -- come from a renaming, possibly in a different scope, and the |
| -- check must be associated with the attribute itself. |
| |
| elsif Id = Attribute_Access |
| and then Nkind (Enc_Object) = N_Explicit_Dereference |
| and then Is_Entity_Name (Prefix (Enc_Object)) |
| and then (Ekind (Btyp) = E_General_Access_Type |
| or else Is_Local_Anonymous_Access (Btyp)) |
| and then Is_Formal (Entity (Prefix (Enc_Object))) |
| and then Ekind (Etype (Entity (Prefix (Enc_Object)))) |
| = E_Anonymous_Access_Type |
| and then Present (Extra_Accessibility |
| (Entity (Prefix (Enc_Object)))) |
| and then not No_Dynamic_Accessibility_Checks_Enabled (Enc_Object) |
| then |
| Apply_Accessibility_Check (Prefix (Enc_Object), Typ, N); |
| |
| -- Ada 2005 (AI-251): If the designated type is an interface we |
| -- add an implicit conversion to force the displacement of the |
| -- pointer to reference the secondary dispatch table. |
| |
| elsif Is_Interface (Btyp_DDT) |
| and then (Comes_From_Source (N) |
| or else Comes_From_Source (Ref_Object) |
| or else (Nkind (Ref_Object) in N_Has_Chars |
| and then Chars (Ref_Object) = Name_uInit)) |
| then |
| if Nkind (Ref_Object) /= N_Explicit_Dereference then |
| |
| -- No implicit conversion required if types match, or if |
| -- the prefix is the class_wide_type of the interface. In |
| -- either case passing an object of the interface type has |
| -- already set the pointer correctly. |
| |
| if Btyp_DDT = Etype (Ref_Object) |
| or else (Is_Class_Wide_Type (Etype (Ref_Object)) |
| and then |
| Class_Wide_Type (Btyp_DDT) = Etype (Ref_Object)) |
| then |
| null; |
| |
| else |
| Rewrite (Prefix (N), |
| Convert_To (Btyp_DDT, |
| New_Copy_Tree (Prefix (N)))); |
| |
| Analyze_And_Resolve (Prefix (N), Btyp_DDT); |
| end if; |
| |
| -- When the object is an explicit dereference, convert the |
| -- dereference's prefix. |
| |
| else |
| declare |
| Obj_DDT : constant Entity_Id := |
| Base_Type |
| (Directly_Designated_Type |
| (Etype (Prefix (Ref_Object)))); |
| begin |
| -- No implicit conversion required if designated types |
| -- match. |
| |
| if Obj_DDT /= Btyp_DDT |
| and then not (Is_Class_Wide_Type (Obj_DDT) |
| and then Etype (Obj_DDT) = Btyp_DDT) |
| then |
| Rewrite (N, |
| Convert_To (Typ, |
| New_Copy_Tree (Prefix (Ref_Object)))); |
| Analyze_And_Resolve (N, Typ); |
| end if; |
| end; |
| end if; |
| end if; |
| end Access_Cases; |
| |
| -------------- |
| -- Adjacent -- |
| -------------- |
| |
| -- Transforms 'Adjacent into a call to the floating-point attribute |
| -- function Adjacent in Fat_xxx (where xxx is the root type) |
| |
| when Attribute_Adjacent => |
| Expand_Fpt_Attribute_RR (N); |
| |
| ------------- |
| -- Address -- |
| ------------- |
| |
| when Attribute_Address => Address : declare |
| Task_Proc : Entity_Id; |
| |
| function Is_Unnested_Component_Init (N : Node_Id) return Boolean; |
| -- Returns True if N is being used to initialize a component of |
| -- an activation record object where the component corresponds to |
| -- the object denoted by the prefix of the attribute N. |
| |
| function Is_Unnested_Component_Init (N : Node_Id) return Boolean is |
| begin |
| return Present (Parent (N)) |
| and then Nkind (Parent (N)) = N_Assignment_Statement |
| and then Is_Entity_Name (Pref) |
| and then Present (Activation_Record_Component (Entity (Pref))) |
| and then Nkind (Name (Parent (N))) = N_Selected_Component |
| and then Entity (Selector_Name (Name (Parent (N)))) = |
| Activation_Record_Component (Entity (Pref)); |
| end Is_Unnested_Component_Init; |
| |
| -- Start of processing for Address |
| |
| begin |
| -- If the prefix is a task or a task type, the useful address is that |
| -- of the procedure for the task body, i.e. the actual program unit. |
| -- We replace the original entity with that of the procedure. |
| |
| if Is_Entity_Name (Pref) |
| and then Is_Task_Type (Entity (Pref)) |
| then |
| Task_Proc := Next_Entity (Root_Type (Ptyp)); |
| |
| while Present (Task_Proc) loop |
| exit when Ekind (Task_Proc) = E_Procedure |
| and then Etype (First_Formal (Task_Proc)) = |
| Corresponding_Record_Type (Ptyp); |
| Next_Entity (Task_Proc); |
| end loop; |
| |
| if Present (Task_Proc) then |
| Set_Entity (Pref, Task_Proc); |
| Set_Etype (Pref, Etype (Task_Proc)); |
| end if; |
| |
| -- Similarly, the address of a protected operation is the address |
| -- of the corresponding protected body, regardless of the protected |
| -- object from which it is selected. |
| |
| elsif Nkind (Pref) = N_Selected_Component |
| and then Is_Subprogram (Entity (Selector_Name (Pref))) |
| and then Is_Protected_Type (Scope (Entity (Selector_Name (Pref)))) |
| then |
| Rewrite (Pref, |
| New_Occurrence_Of ( |
| External_Subprogram (Entity (Selector_Name (Pref))), Loc)); |
| |
| elsif Nkind (Pref) = N_Explicit_Dereference |
| and then Ekind (Ptyp) = E_Subprogram_Type |
| and then Convention (Ptyp) = Convention_Protected |
| then |
| -- The prefix is be a dereference of an access_to_protected_ |
| -- subprogram. The desired address is the second component of |
| -- the record that represents the access. |
| |
| declare |
| Addr : constant Entity_Id := Etype (N); |
| Ptr : constant Node_Id := Prefix (Pref); |
| T : constant Entity_Id := |
| Equivalent_Type (Base_Type (Etype (Ptr))); |
| |
| begin |
| Rewrite (N, |
| Unchecked_Convert_To (Addr, |
| Make_Selected_Component (Loc, |
| Prefix => Unchecked_Convert_To (T, Ptr), |
| Selector_Name => New_Occurrence_Of ( |
| Next_Entity (First_Entity (T)), Loc)))); |
| |
| Analyze_And_Resolve (N, Addr); |
| end; |
| |
| -- Ada 2005 (AI-251): Class-wide interface objects are always |
| -- "displaced" to reference the tag associated with the interface |
| -- type. In order to obtain the real address of such objects we |
| -- generate a call to a run-time subprogram that returns the base |
| -- address of the object. This call is not generated in cases where |
| -- the attribute is being used to initialize a component of an |
| -- activation record object where the component corresponds to |
| -- prefix of the attribute (for back ends that require "unnesting" |
| -- of nested subprograms), since the address needs to be assigned |
| -- as-is to such components. |
| |
| elsif Is_Class_Wide_Type (Ptyp) |
| and then Is_Interface (Underlying_Type (Ptyp)) |
| and then Tagged_Type_Expansion |
| and then not (Nkind (Pref) in N_Has_Entity |
| and then Is_Subprogram (Entity (Pref))) |
| and then not Is_Unnested_Component_Init (N) |
| then |
| Rewrite (N, |
| Make_Function_Call (Loc, |
| Name => New_Occurrence_Of (RTE (RE_Base_Address), Loc), |
| Parameter_Associations => New_List ( |
| Relocate_Node (N)))); |
| Analyze (N); |
| return; |
| end if; |
| |
| -- Deal with packed array reference, other cases are handled by |
| -- the back end. |
| |
| if Involves_Packed_Array_Reference (Pref) then |
| Expand_Packed_Address_Reference (N); |
| end if; |
| end Address; |
| |
| --------------- |
| -- Alignment -- |
| --------------- |
| |
| when Attribute_Alignment => Alignment : declare |
| New_Node : Node_Id; |
| |
| begin |
| -- For class-wide types, X'Class'Alignment is transformed into a |
| -- direct reference to the Alignment of the class type, so that the |
| -- back end does not have to deal with the X'Class'Alignment |
| -- reference. |
| |
| if Is_Entity_Name (Pref) |
| and then Is_Class_Wide_Type (Entity (Pref)) |
| then |
| Rewrite (Prefix (N), New_Occurrence_Of (Entity (Pref), Loc)); |
| return; |
| |
| -- For x'Alignment applied to an object of a class wide type, |
| -- transform X'Alignment into a call to the predefined primitive |
| -- operation _Alignment applied to X. |
| |
| elsif Is_Class_Wide_Type (Ptyp) then |
| New_Node := |
| Make_Attribute_Reference (Loc, |
| Prefix => Pref, |
| Attribute_Name => Name_Tag); |
| |
| New_Node := Build_Get_Alignment (Loc, New_Node); |
| |
| -- Case where the context is an unchecked conversion to a specific |
| -- integer type. We directly convert from the alignment's type. |
| |
| if Nkind (Parent (N)) = N_Unchecked_Type_Conversion then |
| Rewrite (N, New_Node); |
| Analyze_And_Resolve (N); |
| return; |
| |
| -- Case where the context is a specific integer type with which |
| -- the original attribute was compatible. But the alignment has a |
| -- specific type in a-tags.ads (Standard.Natural) so, in order to |
| -- preserve type compatibility, we must convert explicitly. |
| |
| elsif Typ /= Standard_Natural then |
| New_Node := Convert_To (Typ, New_Node); |
| end if; |
| |
| Rewrite (N, New_Node); |
| Analyze_And_Resolve (N, Typ); |
| return; |
| |
| -- For all other cases, we just have to deal with the case of |
| -- the fact that the result can be universal. |
| |
| else |
| Apply_Universal_Integer_Attribute_Checks (N); |
| end if; |
| end Alignment; |
| |
| --------------------------- |
| -- Asm_Input, Asm_Output -- |
| --------------------------- |
| |
| -- The Asm_Input and Asm_Output attributes are not expanded at this |
| -- stage, but will be eliminated in the expansion of the Asm call, |
| -- see Exp_Intr for details. So the back end will never see them. |
| |
| when Attribute_Asm_Input |
| | Attribute_Asm_Output |
| => |
| null; |
| |
| --------- |
| -- Bit -- |
| --------- |
| |
| -- We compute this if a packed array reference was present, otherwise we |
| -- leave the computation up to the back end. |
| |
| when Attribute_Bit => |
| if Involves_Packed_Array_Reference (Pref) then |
| Expand_Packed_Bit_Reference (N); |
| else |
| Apply_Universal_Integer_Attribute_Checks (N); |
| end if; |
| |
| ------------------ |
| -- Bit_Position -- |
| ------------------ |
| |
| -- We leave the computation up to the back end, since we don't know what |
| -- layout will be chosen if no component clause was specified. |
| |
| when Attribute_Bit_Position => |
| Apply_Universal_Integer_Attribute_Checks (N); |
| |
| ------------------ |
| -- Body_Version -- |
| ------------------ |
| |
| -- A reference to P'Body_Version or P'Version is expanded to |
| |
| -- Vnn : Unsigned; |
| -- pragma Import (C, Vnn, "uuuuT"); |
| -- ... |
| -- Get_Version_String (Vnn) |
| |
| -- where uuuu is the unit name (dots replaced by double underscore) |
| -- and T is B for the cases of Body_Version, or Version applied to a |
| -- subprogram acting as its own spec, and S for Version applied to a |
| -- subprogram spec or package. This sequence of code references the |
| -- unsigned constant created in the main program by the binder. |
| |
| -- A special exception occurs for Standard, where the string returned |
| -- is a copy of the library string in gnatvsn.ads. |
| |
| when Attribute_Body_Version |
| | Attribute_Version |
| => |
| Version : declare |
| E : constant Entity_Id := Make_Temporary (Loc, 'V'); |
| Pent : Entity_Id; |
| S : String_Id; |
| |
| begin |
| -- If not library unit, get to containing library unit |
| |
| Pent := Entity (Pref); |
| while Pent /= Standard_Standard |
| and then Scope (Pent) /= Standard_Standard |
| and then not Is_Child_Unit (Pent) |
| loop |
| Pent := Scope (Pent); |
| end loop; |
| |
| -- Special case Standard and Standard.ASCII |
| |
| if Pent = Standard_Standard or else Pent = Standard_ASCII then |
| Rewrite (N, |
| Make_String_Literal (Loc, |
| Strval => Verbose_Library_Version)); |
| |
| -- All other cases |
| |
| else |
| -- Build required string constant |
| |
| Get_Name_String (Get_Unit_Name (Pent)); |
| |
| Start_String; |
| for J in 1 .. Name_Len - 2 loop |
| if Name_Buffer (J) = '.' then |
| Store_String_Chars ("__"); |
| else |
| Store_String_Char (Get_Char_Code (Name_Buffer (J))); |
| end if; |
| end loop; |
| |
| -- Case of subprogram acting as its own spec, always use body |
| |
| if Nkind (Declaration_Node (Pent)) in N_Subprogram_Specification |
| and then Nkind (Parent (Declaration_Node (Pent))) = |
| N_Subprogram_Body |
| and then Acts_As_Spec (Parent (Declaration_Node (Pent))) |
| then |
| Store_String_Chars ("B"); |
| |
| -- Case of no body present, always use spec |
| |
| elsif not Unit_Requires_Body (Pent) then |
| Store_String_Chars ("S"); |
| |
| -- Otherwise use B for Body_Version, S for spec |
| |
| elsif Id = Attribute_Body_Version then |
| Store_String_Chars ("B"); |
| else |
| Store_String_Chars ("S"); |
| end if; |
| |
| S := End_String; |
| Lib.Version_Referenced (S); |
| |
| -- Insert the object declaration |
| |
| Insert_Actions (N, New_List ( |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => E, |
| Object_Definition => |
| New_Occurrence_Of (RTE (RE_Unsigned), Loc)))); |
| |
| -- Set entity as imported with correct external name |
| |
| Set_Is_Imported (E); |
| Set_Interface_Name (E, Make_String_Literal (Loc, S)); |
| |
| -- Set entity as internal to ensure proper Sprint output of its |
| -- implicit importation. |
| |
| Set_Is_Internal (E); |
| |
| -- And now rewrite original reference |
| |
| Rewrite (N, |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Get_Version_String), Loc), |
| Parameter_Associations => New_List ( |
| New_Occurrence_Of (E, Loc)))); |
| end if; |
| |
| Analyze_And_Resolve (N, RTE (RE_Version_String)); |
| end Version; |
| |
| ------------- |
| -- Ceiling -- |
| ------------- |
| |
| -- Transforms 'Ceiling into a call to the floating-point attribute |
| -- function Ceiling in Fat_xxx (where xxx is the root type) |
| |
| when Attribute_Ceiling => |
| Expand_Fpt_Attribute_R (N); |
| |
| -------------- |
| -- Callable -- |
| -------------- |
| |
| -- Transforms 'Callable attribute into a call to the Callable function |
| |
| when Attribute_Callable => |
| |
| -- We have an object of a task interface class-wide type as a prefix |
| -- to Callable. Generate: |
| -- callable (Task_Id (Pref._disp_get_task_id)); |
| |
| if Ada_Version >= Ada_2005 |
| and then Ekind (Ptyp) = E_Class_Wide_Type |
| and then Is_Interface (Ptyp) |
| and then Is_Task_Interface (Ptyp) |
| then |
| Rewrite (N, |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Callable), Loc), |
| Parameter_Associations => New_List ( |
| Unchecked_Convert_To |
| (RTE (RO_ST_Task_Id), |
| Build_Disp_Get_Task_Id_Call (Pref))))); |
| |
| else |
| Rewrite (N, Build_Call_With_Task (Pref, RTE (RE_Callable))); |
| end if; |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| |
| ------------ |
| -- Caller -- |
| ------------ |
| |
| -- Transforms 'Caller attribute into a call to either the |
| -- Task_Entry_Caller or the Protected_Entry_Caller function. |
| |
| when Attribute_Caller => Caller : declare |
| Id_Kind : constant Entity_Id := RTE (RO_AT_Task_Id); |
| Ent : constant Entity_Id := Entity (Pref); |
| Conctype : constant Entity_Id := Scope (Ent); |
| Nest_Depth : Nat := 0; |
| Name : Node_Id; |
| S : Entity_Id; |
| |
| begin |
| -- Protected case |
| |
| if Is_Protected_Type (Conctype) then |
| case Corresponding_Runtime_Package (Conctype) is |
| when System_Tasking_Protected_Objects_Entries => |
| Name := |
| New_Occurrence_Of |
| (RTE (RE_Protected_Entry_Caller), Loc); |
| |
| when System_Tasking_Protected_Objects_Single_Entry => |
| Name := |
| New_Occurrence_Of |
| (RTE (RE_Protected_Single_Entry_Caller), Loc); |
| |
| when others => |
| raise Program_Error; |
| end case; |
| |
| Rewrite (N, |
| Unchecked_Convert_To (Id_Kind, |
| Make_Function_Call (Loc, |
| Name => Name, |
| Parameter_Associations => New_List ( |
| New_Occurrence_Of |
| (Find_Protection_Object (Current_Scope), Loc))))); |
| |
| -- Task case |
| |
| else |
| -- Determine the nesting depth of the E'Caller attribute, that |
| -- is, how many accept statements are nested within the accept |
| -- statement for E at the point of E'Caller. The runtime uses |
| -- this depth to find the specified entry call. |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| S := Scope_Stack.Table (J).Entity; |
| |
| -- We should not reach the scope of the entry, as it should |
| -- already have been checked in Sem_Attr that this attribute |
| -- reference is within a matching accept statement. |
| |
| pragma Assert (S /= Conctype); |
| |
| if S = Ent then |
| exit; |
| |
| elsif Is_Entry (S) then |
| Nest_Depth := Nest_Depth + 1; |
| end if; |
| end loop; |
| |
| Rewrite (N, |
| Unchecked_Convert_To (Id_Kind, |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Task_Entry_Caller), Loc), |
| Parameter_Associations => New_List ( |
| Make_Integer_Literal (Loc, |
| Intval => Nest_Depth))))); |
| end if; |
| |
| Analyze_And_Resolve (N, Id_Kind); |
| end Caller; |
| |
| -------------------- |
| -- Component_Size -- |
| -------------------- |
| |
| -- Component_Size is handled by the back end |
| |
| when Attribute_Component_Size => |
| Apply_Universal_Integer_Attribute_Checks (N); |
| |
| ------------- |
| -- Compose -- |
| ------------- |
| |
| -- Transforms 'Compose into a call to the floating-point attribute |
| -- function Compose in Fat_xxx (where xxx is the root type) |
| |
| -- Note: we strictly should have special code here to deal with the |
| -- case of absurdly negative arguments (less than Integer'First) |
| -- which will return a (signed) zero value, but it hardly seems |
| -- worth the effort. Absurdly large positive arguments will raise |
| -- constraint error which is fine. |
| |
| when Attribute_Compose => |
| Expand_Fpt_Attribute_RI (N); |
| |
| ----------------- |
| -- Constrained -- |
| ----------------- |
| |
| when Attribute_Constrained => Constrained : declare |
| Formal_Ent : constant Entity_Id := Param_Entity (Pref); |
| |
| begin |
| -- Reference to a parameter where the value is passed as an extra |
| -- actual, corresponding to the extra formal referenced by the |
| -- Extra_Constrained field of the corresponding formal. If this |
| -- is an entry in-parameter, it is replaced by a constant renaming |
| -- for which Extra_Constrained is never created. |
| |
| if Present (Formal_Ent) |
| and then Ekind (Formal_Ent) /= E_Constant |
| and then Present (Extra_Constrained (Formal_Ent)) |
| then |
| Rewrite (N, |
| New_Occurrence_Of |
| (Extra_Constrained (Formal_Ent), Loc)); |
| |
| -- If the prefix is an access to object, the attribute applies to |
| -- the designated object, so rewrite with an explicit dereference. |
| |
| elsif Is_Access_Type (Ptyp) |
| and then |
| (not Is_Entity_Name (Pref) or else Is_Object (Entity (Pref))) |
| then |
| Rewrite (Pref, |
| Make_Explicit_Dereference (Loc, Relocate_Node (Pref))); |
| |
| -- For variables with a Extra_Constrained field, we use the |
| -- corresponding entity. |
| |
| elsif Nkind (Pref) = N_Identifier |
| and then Ekind (Entity (Pref)) = E_Variable |
| and then Present (Extra_Constrained (Entity (Pref))) |
| then |
| Rewrite (N, |
| New_Occurrence_Of |
| (Extra_Constrained (Entity (Pref)), Loc)); |
| |
| -- For all other cases, we can tell at compile time |
| |
| else |
| -- For access type, apply access check as needed |
| |
| if Is_Entity_Name (Pref) |
| and then not Is_Type (Entity (Pref)) |
| and then Is_Access_Type (Ptyp) |
| then |
| Apply_Access_Check (N); |
| end if; |
| |
| Rewrite (N, |
| New_Occurrence_Of |
| (Boolean_Literals |
| (Exp_Util.Attribute_Constrained_Static_Value (Pref)), Loc)); |
| end if; |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| end Constrained; |
| |
| --------------- |
| -- Copy_Sign -- |
| --------------- |
| |
| -- Transforms 'Copy_Sign into a call to the floating-point attribute |
| -- function Copy_Sign in Fat_xxx (where xxx is the root type). |
| |
| when Attribute_Copy_Sign => |
| Expand_Fpt_Attribute_RR (N); |
| |
| ----------- |
| -- Count -- |
| ----------- |
| |
| -- Transforms 'Count attribute into a call to the Count function |
| |
| when Attribute_Count => Count : declare |
| Call : Node_Id; |
| Conctyp : Entity_Id; |
| Entnam : Node_Id; |
| Entry_Id : Entity_Id; |
| Index : Node_Id; |
| Name : Node_Id; |
| |
| begin |
| -- If the prefix is a member of an entry family, retrieve both |
| -- entry name and index. For a simple entry there is no index. |
| |
| if Nkind (Pref) = N_Indexed_Component then |
| Entnam := Prefix (Pref); |
| Index := First (Expressions (Pref)); |
| else |
| Entnam := Pref; |
| Index := Empty; |
| end if; |
| |
| Entry_Id := Entity (Entnam); |
| |
| -- Find the concurrent type in which this attribute is referenced |
| -- (there had better be one). |
| |
| Conctyp := Current_Scope; |
| while not Is_Concurrent_Type (Conctyp) loop |
| Conctyp := Scope (Conctyp); |
| end loop; |
| |
| -- Protected case |
| |
| if Is_Protected_Type (Conctyp) then |
| |
| -- No need to transform 'Count into a function call if the current |
| -- scope has been eliminated. In this case such transformation is |
| -- also not viable because the enclosing protected object is not |
| -- available. |
| |
| if Is_Eliminated (Current_Scope) then |
| return; |
| end if; |
| |
| case Corresponding_Runtime_Package (Conctyp) is |
| when System_Tasking_Protected_Objects_Entries => |
| Name := New_Occurrence_Of (RTE (RE_Protected_Count), Loc); |
| |
| Call := |
| Make_Function_Call (Loc, |
| Name => Name, |
| Parameter_Associations => New_List ( |
| New_Occurrence_Of |
| (Find_Protection_Object (Current_Scope), Loc), |
| Entry_Index_Expression |
| (Loc, Entry_Id, Index, Scope (Entry_Id)))); |
| |
| when System_Tasking_Protected_Objects_Single_Entry => |
| Name := |
| New_Occurrence_Of (RTE (RE_Protected_Count_Entry), Loc); |
| |
| Call := |
| Make_Function_Call (Loc, |
| Name => Name, |
| Parameter_Associations => New_List ( |
| New_Occurrence_Of |
| (Find_Protection_Object (Current_Scope), Loc))); |
| |
| when others => |
| raise Program_Error; |
| end case; |
| |
| -- Task case |
| |
| else |
| Call := |
| Make_Function_Call (Loc, |
| Name => New_Occurrence_Of (RTE (RE_Task_Count), Loc), |
| Parameter_Associations => New_List ( |
| Entry_Index_Expression (Loc, |
| Entry_Id, Index, Scope (Entry_Id)))); |
| end if; |
| |
| -- The call returns type Natural but the context is universal integer |
| -- so any integer type is allowed. The attribute was already resolved |
| -- so its Etype is the required result type. If the base type of the |
| -- context type is other than Standard.Integer we put in a conversion |
| -- to the required type. This can be a normal typed conversion since |
| -- both input and output types of the conversion are integer types |
| |
| if Base_Type (Typ) /= Base_Type (Standard_Integer) then |
| Rewrite (N, Convert_To (Typ, Call)); |
| else |
| Rewrite (N, Call); |
| end if; |
| |
| Analyze_And_Resolve (N, Typ); |
| end Count; |
| |
| --------------------- |
| -- Descriptor_Size -- |
| --------------------- |
| |
| -- Descriptor_Size is handled by the back end |
| |
| when Attribute_Descriptor_Size => |
| Apply_Universal_Integer_Attribute_Checks (N); |
| |
| --------------- |
| -- Elab_Body -- |
| --------------- |
| |
| -- This processing is shared by Elab_Spec |
| |
| -- What we do is to insert the following declarations |
| |
| -- procedure tnn; |
| -- pragma Import (C, enn, "name___elabb/s"); |
| |
| -- and then the Elab_Body/Spec attribute is replaced by a reference |
| -- to this defining identifier. |
| |
| when Attribute_Elab_Body |
| | Attribute_Elab_Spec |
| => |
| -- Leave attribute unexpanded in CodePeer mode: the gnat2scil |
| -- back-end knows how to handle these attributes directly. |
| |
| if CodePeer_Mode then |
| return; |
| end if; |
| |
| Elab_Body : declare |
| Ent : constant Entity_Id := Make_Temporary (Loc, 'E'); |
| Str : String_Id; |
| Lang : Node_Id; |
| |
| procedure Make_Elab_String (Nod : Node_Id); |
| -- Given Nod, an identifier, or a selected component, put the |
| -- image into the current string literal, with double underline |
| -- between components. |
| |
| ---------------------- |
| -- Make_Elab_String -- |
| ---------------------- |
| |
| procedure Make_Elab_String (Nod : Node_Id) is |
| begin |
| if Nkind (Nod) = N_Selected_Component then |
| Make_Elab_String (Prefix (Nod)); |
| Store_String_Char ('_'); |
| Store_String_Char ('_'); |
| Get_Name_String (Chars (Selector_Name (Nod))); |
| |
| else |
| pragma Assert (Nkind (Nod) = N_Identifier); |
| Get_Name_String (Chars (Nod)); |
| end if; |
| |
| Store_String_Chars (Name_Buffer (1 .. Name_Len)); |
| end Make_Elab_String; |
| |
| -- Start of processing for Elab_Body/Elab_Spec |
| |
| begin |
| -- First we need to prepare the string literal for the name of |
| -- the elaboration routine to be referenced. |
| |
| Start_String; |
| Make_Elab_String (Pref); |
| Store_String_Chars ("___elab"); |
| Lang := Make_Identifier (Loc, Name_C); |
| |
| if Id = Attribute_Elab_Body then |
| Store_String_Char ('b'); |
| else |
| Store_String_Char ('s'); |
| end if; |
| |
| Str := End_String; |
| |
| Insert_Actions (N, New_List ( |
| Make_Subprogram_Declaration (Loc, |
| Specification => |
| Make_Procedure_Specification (Loc, |
| Defining_Unit_Name => Ent)), |
| |
| Make_Pragma (Loc, |
| Chars => Name_Import, |
| Pragma_Argument_Associations => New_List ( |
| Make_Pragma_Argument_Association (Loc, Expression => Lang), |
| |
| Make_Pragma_Argument_Association (Loc, |
| Expression => Make_Identifier (Loc, Chars (Ent))), |
| |
| Make_Pragma_Argument_Association (Loc, |
| Expression => Make_String_Literal (Loc, Str)))))); |
| |
| Set_Entity (N, Ent); |
| Rewrite (N, New_Occurrence_Of (Ent, Loc)); |
| end Elab_Body; |
| |
| -------------------- |
| -- Elab_Subp_Body -- |
| -------------------- |
| |
| -- Always ignored. In CodePeer mode, gnat2scil knows how to handle |
| -- this attribute directly, and if we are not in CodePeer mode it is |
| -- entirely ignored ??? |
| |
| when Attribute_Elab_Subp_Body => |
| return; |
| |
| ---------------- |
| -- Elaborated -- |
| ---------------- |
| |
| -- Elaborated is always True for preelaborated units, predefined units, |
| -- pure units and units which have Elaborate_Body pragmas. These units |
| -- have no elaboration entity. |
| |
| -- Note: The Elaborated attribute is never passed to the back end |
| |
| when Attribute_Elaborated => Elaborated : declare |
| Elab_Id : constant Entity_Id := Elaboration_Entity (Entity (Pref)); |
| |
| begin |
| if Present (Elab_Id) then |
| Rewrite (N, |
| Make_Op_Ne (Loc, |
| Left_Opnd => New_Occurrence_Of (Elab_Id, Loc), |
| Right_Opnd => Make_Integer_Literal (Loc, Uint_0))); |
| |
| Analyze_And_Resolve (N, Typ); |
| else |
| Rewrite (N, New_Occurrence_Of (Standard_True, Loc)); |
| end if; |
| end Elaborated; |
| |
| -------------- |
| -- Enum_Rep -- |
| -------------- |
| |
| when Attribute_Enum_Rep => Enum_Rep : declare |
| Expr : Node_Id; |
| |
| begin |
| -- Get the expression, which is X for Enum_Type'Enum_Rep (X) or |
| -- X'Enum_Rep. |
| |
| if Is_Non_Empty_List (Exprs) then |
| Expr := First (Exprs); |
| else |
| Expr := Pref; |
| end if; |
| |
| -- If not constant-folded, Enum_Type'Enum_Rep (X) or X'Enum_Rep |
| -- expands to |
| |
| -- target-type!(X) |
| |
| -- This is an unchecked conversion from the enumeration type to the |
| -- target integer type, which is treated by the back end as a normal |
| -- integer conversion, treating the enumeration type as an integer, |
| -- which is exactly what we want. Unlike for the Pos attribute, we |
| -- cannot use a regular conversion since the associated check would |
| -- involve comparing the converted bounds, i.e. would involve the use |
| -- of 'Pos instead 'Enum_Rep for these bounds. |
| |
| -- However the target type is universal integer in most cases, which |
| -- is a very large type, so in the case of an enumeration type, we |
| -- first convert to a small signed integer type in order not to lose |
| -- the size information. |
| |
| if Is_Enumeration_Type (Ptyp) then |
| Rewrite (N, Unchecked_Convert_To (Get_Integer_Type (Ptyp), Expr)); |
| Convert_To_And_Rewrite (Typ, N); |
| |
| -- Deal with integer types (replace by conversion) |
| |
| else |
| Rewrite (N, Convert_To (Typ, Expr)); |
| end if; |
| |
| Analyze_And_Resolve (N, Typ); |
| end Enum_Rep; |
| |
| -------------- |
| -- Enum_Val -- |
| -------------- |
| |
| when Attribute_Enum_Val => Enum_Val : declare |
| Expr : Node_Id; |
| Btyp : constant Entity_Id := Base_Type (Ptyp); |
| |
| begin |
| -- X'Enum_Val (Y) expands to |
| |
| -- [constraint_error when _rep_to_pos (Y, False) = -1, msg] |
| -- X!(Y); |
| |
| Expr := Unchecked_Convert_To (Ptyp, First (Exprs)); |
| |
| -- Ensure that the expression is not truncated since the "bad" bits |
| -- are desired. |
| |
| if Nkind (Expr) = N_Unchecked_Type_Conversion then |
| Set_No_Truncation (Expr); |
| end if; |
| |
| Insert_Action (N, |
| Make_Raise_Constraint_Error (Loc, |
| Condition => |
| Make_Op_Eq (Loc, |
| Left_Opnd => |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (TSS (Btyp, TSS_Rep_To_Pos), Loc), |
| Parameter_Associations => New_List ( |
| Relocate_Node (Duplicate_Subexpr (Expr)), |
| New_Occurrence_Of (Standard_False, Loc))), |
| |
| Right_Opnd => Make_Integer_Literal (Loc, -1)), |
| Reason => CE_Range_Check_Failed)); |
| |
| Rewrite (N, Expr); |
| Analyze_And_Resolve (N, Ptyp); |
| end Enum_Val; |
| |
| -------------- |
| -- Exponent -- |
| -------------- |
| |
| -- Transforms 'Exponent into a call to the floating-point attribute |
| -- function Exponent in Fat_xxx (where xxx is the root type) |
| |
| when Attribute_Exponent => |
| Expand_Fpt_Attribute_R (N); |
| |
| ------------------ |
| -- External_Tag -- |
| ------------------ |
| |
| -- transforme X'External_Tag into Ada.Tags.External_Tag (X'tag) |
| |
| when Attribute_External_Tag => |
| Rewrite (N, |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_External_Tag), Loc), |
| Parameter_Associations => New_List ( |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Tag, |
| Prefix => Prefix (N))))); |
| |
| Analyze_And_Resolve (N, Standard_String); |
| |
| ----------------------- |
| -- Finalization_Size -- |
| ----------------------- |
| |
| when Attribute_Finalization_Size => Finalization_Size : declare |
| function Calculate_Header_Size return Node_Id; |
| -- Generate a runtime call to calculate the size of the hidden header |
| -- along with any added padding which would precede a heap-allocated |
| -- object of the prefix type. |
| |
| --------------------------- |
| -- Calculate_Header_Size -- |
| --------------------------- |
| |
| function Calculate_Header_Size return Node_Id is |
| begin |
| -- Generate: |
| -- Typ (Header_Size_With_Padding (Pref'Alignment)) |
| |
| return |
| Convert_To (Typ, |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Header_Size_With_Padding), Loc), |
| |
| Parameter_Associations => New_List ( |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Copy_Tree (Pref), |
| Attribute_Name => Name_Alignment)))); |
| end Calculate_Header_Size; |
| |
| -- Local variables |
| |
| Size : Entity_Id; |
| |
| -- Start of processing for Finalization_Size |
| |
| begin |
| -- An object of a class-wide type first requires a runtime check to |
| -- determine whether it is actually controlled or not. Depending on |
| -- the outcome of this check, the Finalization_Size of the object |
| -- may be zero or some positive value. |
| -- |
| -- In this scenario, Pref'Finalization_Size is expanded into |
| -- |
| -- Size : Integer := 0; |
| -- |
| -- if Needs_Finalization (Pref'Tag) then |
| -- Size := Integer (Header_Size_With_Padding (Pref'Alignment)); |
| -- end if; |
| -- |
| -- and the attribute reference is replaced with a reference to Size. |
| |
| if Is_Class_Wide_Type (Ptyp) then |
| Size := Make_Temporary (Loc, 'S'); |
| |
| Insert_Actions (N, New_List ( |
| |
| -- Generate: |
| -- Size : Integer := 0; |
| |
| Make_Object_Declaration (Loc, |
| Defining_Identifier => Size, |
| Object_Definition => |
| New_Occurrence_Of (Standard_Integer, Loc), |
| Expression => Make_Integer_Literal (Loc, 0)), |
| |
| -- Generate: |
| -- if Needs_Finalization (Pref'Tag) then |
| -- Size := |
| -- Integer (Header_Size_With_Padding (Pref'Alignment)); |
| -- end if; |
| |
| Make_If_Statement (Loc, |
| Condition => |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Needs_Finalization), Loc), |
| |
| Parameter_Associations => New_List ( |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Copy_Tree (Pref), |
| Attribute_Name => Name_Tag))), |
| |
| Then_Statements => New_List ( |
| Make_Assignment_Statement (Loc, |
| Name => New_Occurrence_Of (Size, Loc), |
| Expression => |
| Convert_To |
| (Standard_Integer, Calculate_Header_Size)))))); |
| |
| Rewrite (N, New_Occurrence_Of (Size, Loc)); |
| |
| -- The prefix is known to be controlled at compile time. Calculate |
| -- Finalization_Size by calling function Header_Size_With_Padding. |
| |
| elsif Needs_Finalization (Ptyp) then |
| Rewrite (N, Calculate_Header_Size); |
| |
| -- The prefix is not an object with controlled parts, so its |
| -- Finalization_Size is zero. |
| |
| else |
| Rewrite (N, Make_Integer_Literal (Loc, 0)); |
| end if; |
| |
| -- Due to cases where the entity type of the attribute is already |
| -- resolved the rewritten N must get re-resolved to its appropriate |
| -- type. |
| |
| Analyze_And_Resolve (N, Typ); |
| end Finalization_Size; |
| |
| ----------------- |
| -- First, Last -- |
| ----------------- |
| |
| when Attribute_First |
| | Attribute_Last |
| => |
| -- If the prefix type is a constrained packed array type which |
| -- already has a Packed_Array_Impl_Type representation defined, then |
| -- replace this attribute with a direct reference to the attribute of |
| -- the appropriate index subtype (since otherwise the back end will |
| -- try to give us the value of 'First for this implementation type). |
| -- Do not do this if Ptyp depends on a discriminant as its bounds |
| -- are only available through N. |
| |
| if Is_Constrained_Packed_Array (Ptyp) |
| and then not Size_Depends_On_Discriminant (Ptyp) |
| then |
| Rewrite (N, |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Attribute_Name (N), |
| Prefix => |
| New_Occurrence_Of (Get_Index_Subtype (N), Loc))); |
| Analyze_And_Resolve (N, Typ); |
| |
| -- For a constrained array type, if the bound is a reference to an |
| -- entity which is not a discriminant, just replace with a direct |
| -- reference. Note that this must be in keeping with what is done |
| -- for scalar types in order for range checks to be elided in loops. |
| |
| -- However, avoid doing it if the array type is public because, in |
| -- this case, we effectively rely on the back end to create public |
| -- symbols with consistent names across units for the array bounds. |
| |
| elsif Is_Array_Type (Ptyp) |
| and then Is_Constrained (Ptyp) |
| and then not Is_Public (Ptyp) |
| then |
| declare |
| Bnd : Node_Id; |
| |
| begin |
| if Id = Attribute_First then |
| Bnd := Type_Low_Bound (Get_Index_Subtype (N)); |
| else |
| Bnd := Type_High_Bound (Get_Index_Subtype (N)); |
| end if; |
| |
| if Is_Entity_Name (Bnd) |
| and then Ekind (Entity (Bnd)) /= E_Discriminant |
| then |
| Rewrite (N, New_Occurrence_Of (Entity (Bnd), Loc)); |
| end if; |
| end; |
| |
| -- For access type, apply access check as needed |
| |
| elsif Is_Access_Type (Ptyp) then |
| Apply_Access_Check (N); |
| |
| -- For scalar type, if the bound is a reference to an entity, just |
| -- replace with a direct reference. Note that we can only have a |
| -- reference to a constant entity at this stage, anything else would |
| -- have already been rewritten. |
| |
| elsif Is_Scalar_Type (Ptyp) then |
| declare |
| Bnd : Node_Id; |
| |
| begin |
| if Id = Attribute_First then |
| Bnd := Type_Low_Bound (Ptyp); |
| else |
| Bnd := Type_High_Bound (Ptyp); |
| end if; |
| |
| if Is_Entity_Name (Bnd) then |
| Rewrite (N, New_Occurrence_Of (Entity (Bnd), Loc)); |
| end if; |
| end; |
| end if; |
| |
| --------------- |
| -- First_Bit -- |
| --------------- |
| |
| -- We leave the computation up to the back end, since we don't know what |
| -- layout will be chosen if no component clause was specified. |
| |
| when Attribute_First_Bit => |
| Apply_Universal_Integer_Attribute_Checks (N); |
| |
| -------------------------------- |
| -- Fixed_Value, Integer_Value -- |
| -------------------------------- |
| |
| -- We transform |
| |
| -- fixtype'Fixed_Value (integer-value) |
| -- inttype'Integer_Value (fixed-value) |
| |
| -- into |
| |
| -- fixtype (integer-value) |
| -- inttype (fixed-value) |
| |
| -- respectively. |
| |
| -- We set Conversion_OK on the conversion because we do not want it |
| -- to go through the fixed-point conversion circuits. |
| |
| when Attribute_Fixed_Value |
| | Attribute_Integer_Value |
| => |
| Rewrite (N, OK_Convert_To (Entity (Pref), First (Exprs))); |
| |
| -- Note that it might appear that a properly analyzed unchecked |
| -- conversion would be just fine here, but that's not the case, |
| -- since the full range checks performed by the following calls |
| -- are critical. |
| |
| Apply_Type_Conversion_Checks (N); |
| |
| -- Note that Apply_Type_Conversion_Checks only deals with the |
| -- overflow checks on conversions involving fixed-point types |
| -- so we must apply range checks manually on them and expand. |
| |
| Apply_Scalar_Range_Check |
| (Expression (N), Etype (N), Fixed_Int => True); |
| |
| Set_Analyzed (N); |
| Expand (N); |
| |
| ----------- |
| -- Floor -- |
| ----------- |
| |
| -- Transforms 'Floor into a call to the floating-point attribute |
| -- function Floor in Fat_xxx (where xxx is the root type) |
| |
| when Attribute_Floor => |
| Expand_Fpt_Attribute_R (N); |
| |
| ---------- |
| -- Fore -- |
| ---------- |
| |
| -- For the fixed-point type Typ: |
| |
| -- Typ'Fore |
| |
| -- expands into |
| |
| -- System.Fore_xx (ftyp (Typ'First), ftyp (Typ'Last) [,pm]) |
| |
| -- For decimal fixed-point types |
| -- xx = Decimal{32,64,128} |
| -- ftyp = Integer_{32,64,128} |
| -- pm = Typ'Scale |
| |
| -- For the most common ordinary fixed-point types |
| -- xx = Fixed{32,64,128} |
| -- ftyp = Integer_{32,64,128} |
| -- pm = numerator of Typ'Small |
| -- denominator of Typ'Small |
| -- min (scale of Typ'Small, 0) |
| |
| -- For other ordinary fixed-point types |
| -- xx = Fixed |
| -- ftyp = Long_Float |
| -- pm = none |
| |
| -- Note that we know that the type is a nonstatic subtype, or Fore would |
| -- have been computed statically in Eval_Attribute. |
| |
| when Attribute_Fore => |
| declare |
| Arg_List : List_Id; |
| Fid : RE_Id; |
| Ftyp : Entity_Id; |
| |
| begin |
| if Is_Decimal_Fixed_Point_Type (Ptyp) then |
| if Esize (Ptyp) <= 32 then |
| Fid := RE_Fore_Decimal32; |
| Ftyp := RTE (RE_Integer_32); |
| elsif Esize (Ptyp) <= 64 then |
| Fid := RE_Fore_Decimal64; |
| Ftyp := RTE (RE_Integer_64); |
| else |
| Fid := RE_Fore_Decimal128; |
| Ftyp := RTE (RE_Integer_128); |
| end if; |
| |
| else |
| declare |
| Num : constant Uint := Norm_Num (Small_Value (Ptyp)); |
| Den : constant Uint := Norm_Den (Small_Value (Ptyp)); |
| Max : constant Uint := UI_Max (Num, Den); |
| Min : constant Uint := UI_Min (Num, Den); |
| Siz : constant Uint := Esize (Ptyp); |
| |
| begin |
| if Siz <= 32 |
| and then Max <= Uint_2 ** 31 |
| and then (Min = Uint_1 |
| or else Num < Den |
| or else Num < Uint_10 ** 8) |
| then |
| Fid := RE_Fore_Fixed32; |
| Ftyp := RTE (RE_Integer_32); |
| elsif Siz <= 64 |
| and then Max <= Uint_2 ** 63 |
| and then (Min = Uint_1 |
| or else Num < Den |
| or else Num < Uint_10 ** 17) |
| then |
| Fid := RE_Fore_Fixed64; |
| Ftyp := RTE (RE_Integer_64); |
| elsif System_Max_Integer_Size = 128 |
| and then Max <= Uint_2 ** 127 |
| and then (Min = Uint_1 |
| or else Num < Den |
| or else Num < Uint_10 ** 37) |
| then |
| Fid := RE_Fore_Fixed128; |
| Ftyp := RTE (RE_Integer_128); |
| else |
| Fid := RE_Fore_Fixed; |
| Ftyp := Standard_Long_Float; |
| end if; |
| end; |
| end if; |
| |
| Arg_List := New_List ( |
| Convert_To (Ftyp, |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Occurrence_Of (Ptyp, Loc), |
| Attribute_Name => Name_First))); |
| |
| Append_To (Arg_List, |
| Convert_To (Ftyp, |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Occurrence_Of (Ptyp, Loc), |
| Attribute_Name => Name_Last))); |
| |
| -- For decimal, append Scale and also set to do literal conversion |
| |
| if Is_Decimal_Fixed_Point_Type (Ptyp) then |
| Set_Conversion_OK (First (Arg_List)); |
| Set_Conversion_OK (Next (First (Arg_List))); |
| |
| Append_To (Arg_List, |
| Make_Integer_Literal (Loc, Scale_Value (Ptyp))); |
| |
| -- For ordinary fixed-point types, append Num, Den and Scale |
| -- parameters and also set to do literal conversion |
| |
| elsif Fid /= RE_Fore_Fixed then |
| Set_Conversion_OK (First (Arg_List)); |
| Set_Conversion_OK (Next (First (Arg_List))); |
| |
| Append_To (Arg_List, |
| Make_Integer_Literal (Loc, -Norm_Num (Small_Value (Ptyp)))); |
| |
| Append_To (Arg_List, |
| Make_Integer_Literal (Loc, -Norm_Den (Small_Value (Ptyp)))); |
| |
| declare |
| Val : Ureal := Small_Value (Ptyp); |
| Scale : Int := 0; |
| |
| begin |
| while Val >= Ureal_10 loop |
| Val := Val / Ureal_10; |
| Scale := Scale - 1; |
| end loop; |
| |
| Append_To (Arg_List, |
| Make_Integer_Literal (Loc, UI_From_Int (Scale))); |
| end; |
| end if; |
| |
| Rewrite (N, |
| Convert_To (Typ, |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (Fid), Loc), |
| Parameter_Associations => Arg_List))); |
| |
| Analyze_And_Resolve (N, Typ); |
| end; |
| |
| -------------- |
| -- Fraction -- |
| -------------- |
| |
| -- Transforms 'Fraction into a call to the floating-point attribute |
| -- function Fraction in Fat_xxx (where xxx is the root type) |
| |
| when Attribute_Fraction => |
| Expand_Fpt_Attribute_R (N); |
| |
| -------------- |
| -- From_Any -- |
| -------------- |
| |
| when Attribute_From_Any => From_Any : declare |
| Decls : constant List_Id := New_List; |
| |
| begin |
| Rewrite (N, |
| Build_From_Any_Call (Ptyp, |
| Relocate_Node (First (Exprs)), |
| Decls)); |
| Insert_Actions (N, Decls); |
| Analyze_And_Resolve (N, Ptyp); |
| end From_Any; |
| |
| ---------------------- |
| -- Has_Same_Storage -- |
| ---------------------- |
| |
| when Attribute_Has_Same_Storage => Has_Same_Storage : declare |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| X : constant Node_Id := Prefix (N); |
| Y : constant Node_Id := First (Expressions (N)); |
| -- The arguments |
| |
| X_Addr : Node_Id; |
| Y_Addr : Node_Id; |
| -- Rhe expressions for their addresses |
| |
| X_Size : Node_Id; |
| Y_Size : Node_Id; |
| -- Rhe expressions for their sizes |
| |
| begin |
| -- The attribute is expanded as: |
| |
| -- (X'address = Y'address) |
| -- and then (X'Size = Y'Size) |
| -- and then (X'Size /= 0) (AI12-0077) |
| |
| -- If both arguments have the same Etype the second conjunct can be |
| -- omitted. |
| |
| X_Addr := |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Address, |
| Prefix => New_Copy_Tree (X)); |
| |
| Y_Addr := |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Address, |
| Prefix => New_Copy_Tree (Y)); |
| |
| X_Size := |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Size, |
| Prefix => New_Copy_Tree (X)); |
| |
| if Etype (X) = Etype (Y) then |
| Rewrite (N, |
| Make_And_Then (Loc, |
| Left_Opnd => |
| Make_Op_Eq (Loc, |
| Left_Opnd => X_Addr, |
| Right_Opnd => Y_Addr), |
| Right_Opnd => |
| Make_Op_Ne (Loc, |
| Left_Opnd => X_Size, |
| Right_Opnd => Make_Integer_Literal (Loc, 0)))); |
| else |
| Y_Size := |
| Make_Attribute_Reference (Loc, |
| Attribute_Name => Name_Size, |
| Prefix => New_Copy_Tree (Y)); |
| |
| Rewrite (N, |
| Make_And_Then (Loc, |
| Left_Opnd => |
| Make_Op_Eq (Loc, |
| Left_Opnd => X_Addr, |
| Right_Opnd => Y_Addr), |
| Right_Opnd => |
| Make_And_Then (Loc, |
| Left_Opnd => |
| Make_Op_Eq (Loc, |
| Left_Opnd => X_Size, |
| Right_Opnd => Y_Size), |
| Right_Opnd => |
| Make_Op_Ne (Loc, |
| Left_Opnd => New_Copy_Tree (X_Size), |
| Right_Opnd => Make_Integer_Literal (Loc, 0))))); |
| end if; |
| |
| Analyze_And_Resolve (N, Standard_Boolean); |
| end Has_Same_Storage; |
| |
| -------------- |
| -- Identity -- |
| -------------- |
| |
| -- For an exception returns a reference to the exception data: |
| -- Exception_Id!(Prefix'Reference) |
| |
| -- For a task it returns a reference to the _task_id component of |
| -- corresponding record: |
| |
| -- taskV!(Prefix)._Task_Id, converted to the type Task_Id defined |
| |
| -- in Ada.Task_Identification |
| |
| when Attribute_Identity => Identity : declare |
| Id_Kind : Entity_Id; |
| |
| begin |
| if Ptyp = Standard_Exception_Type then |
| Id_Kind := RTE (RE_Exception_Id); |
| |
| if Present (Renamed_Entity (Entity (Pref))) then |
| Set_Entity (Pref, Renamed_Entity (Entity (Pref))); |
| end if; |
| |
| Rewrite (N, |
| Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref))); |
| else |
| Id_Kind := RTE (RO_AT_Task_Id); |
| |
| -- If the prefix is a task interface, the Task_Id is obtained |
| -- dynamically through a dispatching call, as for other task |
| -- attributes applied to interfaces. |
| |
| if Ada_Version >= Ada_2005 |
| and then Ekind (Ptyp) = E_Class_Wide_Type |
| and then Is_Interface (Ptyp) |
| and then Is_Task_Interface (Ptyp) |
| then |
| Rewrite (N, |
| Unchecked_Convert_To |
| (Id_Kind, Build_Disp_Get_Task_Id_Call (Pref))); |
| |
| else |
| Rewrite (N, |
| Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref))); |
| end if; |
| end if; |
| |
| Analyze_And_Resolve (N, Id_Kind); |
| end Identity; |
| |
| ----------- |
| -- Image -- |
| ----------- |
| |
| when Attribute_Image => |
| |
| -- Leave attribute unexpanded in CodePeer mode: the gnat2scil |
| -- back-end knows how to handle this attribute directly. |
| |
| if CodePeer_Mode then |
| return; |
| end if; |
| |
| Exp_Imgv.Expand_Image_Attribute (N); |
| |
| --------- |
| -- Img -- |
| --------- |
| |
| -- X'Img is expanded to typ'Image (X), where typ is the type of X |
| |
| when Attribute_Img => |
| Exp_Imgv.Expand_Image_Attribute (N); |
| |
| ----------------- |
| -- Initialized -- |
| ----------------- |
| |
| -- For execution, we could either implement an approximation of this |
| -- aspect, or use Valid_Scalars as a first approximation. For now we do |
| -- the latter. |
| |
| when Attribute_Initialized => |
| |
| -- Do not expand 'Initialized in CodePeer mode, it will be handled |
| -- by the back-end directly. |
| |
| if CodePeer_Mode then |
| return; |
| end if; |
| |
| Rewrite |
| (N, |
| Make_Attribute_Reference |
| (Sloc => Loc, |
| Prefix => Pref, |
| Attribute_Name => Name_Valid_Scalars, |
| Expressions => Exprs)); |
| |
| Analyze_And_Resolve (N); |
| |
| ----------- |
| -- Input -- |
| ----------- |
| |
| when Attribute_Input => Input : declare |
| P_Type : constant Entity_Id := Entity (Pref); |
| B_Type : constant Entity_Id := Base_Type (P_Type); |
| U_Type : constant Entity_Id := Underlying_Type (P_Type); |
| Strm : constant Node_Id := First (Exprs); |
| Fname : Entity_Id; |
| Decl : Node_Id; |
| Call : Node_Id; |
| Prag : Node_Id; |
| Arg2 : Node_Id; |
| Rfunc : Node_Id; |
| |
| Cntrl : Node_Id := Empty; |
| -- Value for controlling argument in call. Always Empty except in |
| -- the dispatching (class-wide type) case, where it is a reference |
| -- to the dummy object initialized to the right internal tag. |
| |
| procedure Freeze_Stream_Subprogram (F : Entity_Id); |
| -- The expansion of the attribute reference may generate a call to |
| -- a user-defined stream subprogram that is frozen by the call. This |
| -- can lead to access-before-elaboration problem if the reference |
| -- appears in an object declaration and the subprogram body has not |
| -- been seen. The freezing of the subprogram requires special code |
| -- because it appears in an expanded context where expressions do |
| -- not freeze their constituents. |
| |
| ------------------------------ |
| -- Freeze_Stream_Subprogram -- |
| ------------------------------ |
| |
| procedure Freeze_Stream_Subprogram (F : Entity_Id) is |
| Decl : constant Node_Id := Unit_Declaration_Node (F); |
| Bod : Node_Id; |
| |
| begin |
| -- If this is user-defined subprogram, the corresponding |
| -- stream function appears as a renaming-as-body, and the |
| -- user subprogram must be retrieved by tree traversal. |
| |
| if Present (Decl) |
| and then Nkind (Decl) = N_Subprogram_Declaration |
| and then Present (Corresponding_Body (Decl)) |
| then |
| Bod := Corresponding_Body (Decl); |
| |
| if Nkind (Unit_Declaration_Node (Bod)) = |
| N_Subprogram_Renaming_Declaration |
| then |
| Set_Is_Frozen (Entity (Name (Unit_Declaration_Node (Bod)))); |
| end if; |
| end if; |
| end Freeze_Stream_Subprogram; |
| |
| -- Start of processing for Input |
| |
| begin |
| -- If no underlying type, we have an error that will be diagnosed |
| -- elsewhere, so here we just completely ignore the expansion. |
| |
| if No (U_Type) then |
| return; |
| end if; |
| |
| -- Stream operations can appear in user code even if the restriction |
| -- No_Streams is active (for example, when instantiating a predefined |
| -- container). In that case rewrite the attribute as a Raise to |
| -- prevent any run-time use. |
| |
| if Restriction_Active (No_Streams) then |
| Rewrite (N, |
| Make_Raise_Program_Error (Sloc (N), |
| Reason => PE_Stream_Operation_Not_Allowed)); |
| Set_Etype (N, B_Type); |
| return; |
| end if; |
| |
| -- If there is a TSS for Input, just call it |
| |
| Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input); |
| |
| if Present (Fname) then |
| null; |
| |
| else |
| -- If there is a Stream_Convert pragma, use it, we rewrite |
| |
| -- sourcetyp'Input (stream) |
| |
| -- as |
| |
| -- sourcetyp (streamread (strmtyp'Input (stream))); |
| |
| -- where streamread is the given Read function that converts an |
| -- argument of type strmtyp to type sourcetyp or a type from which |
| -- it is derived (extra conversion required for the derived case). |
| |
| Prag := Get_Stream_Convert_Pragma (P_Type); |
| |
| if Present (Prag) then |
| Arg2 := Next (First (Pragma_Argument_Associations (Prag))); |
| Rfunc := Entity (Expression (Arg2)); |
| |
| Rewrite (N, |
| Convert_To (B_Type, |
| Make_Function_Call (Loc, |
| Name => New_Occurrence_Of (Rfunc, Loc), |
| Parameter_Associations => New_List ( |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| New_Occurrence_Of |
| (Etype (First_Formal (Rfunc)), Loc), |
| Attribute_Name => Name_Input, |
| Expressions => Exprs))))); |
| |
| Analyze_And_Resolve (N, B_Type); |
| return; |
| |
| -- Limited types |
| |
| elsif Default_Streaming_Unavailable (U_Type) then |
| -- Do the same thing here as is done above in the |
| -- case where a No_Streams restriction is active. |
| |
| Rewrite (N, |
| Make_Raise_Program_Error (Sloc (N), |
| Reason => PE_Stream_Operation_Not_Allowed)); |
| Set_Etype (N, B_Type); |
| return; |
| |
| -- Elementary types |
| |
| elsif Is_Elementary_Type (U_Type) then |
| |
| -- A special case arises if we have a defined _Read routine, |
| -- since in this case we are required to call this routine. |
| |
| if Present (Find_Inherited_TSS (P_Type, TSS_Stream_Read)) then |
| Build_Record_Or_Elementary_Input_Function |
| (Loc, P_Type, Decl, Fname); |
| Insert_Action (N, Decl); |
| |
| -- For normal cases, we call the I_xxx routine directly |
| |
| else |
| Rewrite (N, Build_Elementary_Input_Call (N)); |
| Analyze_And_Resolve (N, P_Type); |
| return; |
| end if; |
| |
| -- Array type case |
| |
| elsif Is_Array_Type (U_Type) then |
| Build_Array_Input_Function (Loc, U_Type, Decl, Fname); |
| Compile_Stream_Body_In_Scope (N, Decl, U_Type); |
| |
| -- Dispatching case with class-wide type |
| |
| elsif Is_Class_Wide_Type (P_Type) then |
| |
| -- No need to do anything else compiling under restriction |
| -- No_Dispatching_Calls. During the semantic analysis we |
| -- already notified such violation. |
| |
| if Restriction_Active (No_Dispatching_Calls) then |
| return; |
| end if; |
| |
| declare |
| Rtyp : constant Entity_Id := Root_Type (P_Type); |
| |
| Expr : Node_Id; -- call to Descendant_Tag |
| Get_Tag : Node_Id; -- expression to read the 'Tag |
| |
| begin |
| -- Read the internal tag (RM 13.13.2(34)) and use it to |
| -- initialize a dummy tag value. We used to unconditionally |
| -- generate: |
| -- |
| -- Descendant_Tag (String'Input (Strm), P_Type); |
| -- |
| -- which turns into a call to String_Input_Blk_IO. However, |
| -- if the input is malformed, that could try to read an |
| -- enormous String, causing chaos. So instead we call |
| -- String_Input_Tag, which does the same thing as |
| -- String_Input_Blk_IO, except that if the String is |
| -- absurdly long, it raises an exception. |
| -- |
| -- However, if the No_Stream_Optimizations restriction |
| -- is active, we disable this unnecessary attempt at |
| -- robustness; we really need to read the string |
| -- character-by-character. |
| -- |
| -- This value is used only to provide a controlling |
| -- argument for the eventual _Input call. Descendant_Tag is |
| -- called rather than Internal_Tag to ensure that we have a |
| -- tag for a type that is descended from the prefix type and |
| -- declared at the same accessibility level (the exception |
| -- Tag_Error will be raised otherwise). The level check is |
| -- required for Ada 2005 because tagged types can be |
| -- extended in nested scopes (AI-344). |
| |
| -- Note: we used to generate an explicit declaration of a |
| -- constant Ada.Tags.Tag object, and use an occurrence of |
| -- this constant in Cntrl, but this caused a secondary stack |
| -- leak. |
| |
| if Restriction_Active (No_Stream_Optimizations) then |
| Get_Tag := |
| Make_Attribute_Reference (Loc, |
| Prefix => |
| New_Occurrence_Of (Standard_String, Loc), |
| Attribute_Name => Name_Input, |
| Expressions => New_List ( |
| Relocate_Node (Duplicate_Subexpr (Strm)))); |
| else |
| Get_Tag := |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of |
| (RTE (RE_String_Input_Tag), Loc), |
| Parameter_Associations => New_List ( |
| Relocate_Node (Duplicate_Subexpr (Strm)))); |
| end if; |
| |
| Expr := |
| Make_Function_Call (Loc, |
| Name => |
| New_Occurrence_Of (RTE (RE_Descendant_Tag), Loc), |
| Parameter_Associations => New_List ( |
| Get_Tag, |
| Make_Attribute_Reference (Loc, |
| Prefix => New_Occurrence_Of (P_Type, Loc), |
| Attribute_Name => Name_Tag))); |
| |
| Set_Etype (Expr, RTE (RE_Tag)); |
| |
| -- Now we need to get the entity for the call, and construct |
| -- a function call node, where we preset a reference to Dnn |
| -- as the controlling argument (doing an unchecked convert |
| -- to the class-wide tagged type to make it look like a real |
| -- tagged object). |
| |
| Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input); |
| Cntrl := Unchecked_Convert_To (P_Type, Expr); |
| Set_Etype (Cntrl, P_Type); |
| Set_Parent (Cntrl, N); |
| end; |
| |
| -- For tagged types, use the primitive Input function |
| |
| elsif Is_Tagged_Type (U_Type) then |
| Fname := Find_Prim_Op (U_Type, TSS_Stream_Input); |
| |
| -- All other record type cases, including protected records. The |
| -- latter only arise for expander generated code for handling |
| -- shared passive partition access. |
| |
| else |
| pragma Assert |
| (Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type)); |
| |
| -- Ada 2005 (AI-216): Program_Error is raised executing default |
| -- implementation of the Input attribute of an unchecked union |
| -- type if the type lacks default discriminant values. |
| |
| if Is_Unchecked_Union (Base_Type (U_Type)) |
| and then |
| No (Discriminant_Default_Value (First_Discriminant (U_Type))) |
| then |
| Rewrite (N, |
| Make_Raise_Program_Error (Loc, |
| Reason => PE_Unchecked_Union_Restriction)); |
| Set_Etype (N, B_Type); |
| return; |
| end if; |
| |
| -- Build the type's Input function, passing the subtype rather |
| -- than its base type, because checks are needed in the case of |
| -- constrained discriminants (see Ada 2012 AI05-0192). |
| |
| Build_Record_Or_Elementary_Input_Function |
| (Loc, U_Type, Decl, Fname); |
| Insert_Action (N, Decl); |
| |
| if Nkind (Parent (N)) = N_Object_Declaration |
| and then Is_Record_Type (U_Type) |
| then |
|
|