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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ A T T R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, 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 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,
In_Present => True,
Out_Present => False,
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);
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