Google Git
Sign in
gnu / gcc / 57ea00136418991e847e46a6946a81a1df70c9a4 / . / gcc / ada / exp_attr.adb
blob: f296a6f60cfb76692e053cc98298f5a98ae205e8 [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ A T T R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2003 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Exp_Ch2; use Exp_Ch2;
with Exp_Ch9; use Exp_Ch9;
with Exp_Imgv; use Exp_Imgv;
with Exp_Pakd; use Exp_Pakd;
with Exp_Strm; use Exp_Strm;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Gnatvsn; use Gnatvsn;
with Hostparm; use Hostparm;
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 Rtsfind; use Rtsfind;
with Sem; use Sem;
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 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 Validsw; use Validsw;
package body Exp_Attr is
-----------------------
-- Local Subprograms --
-----------------------
procedure Compile_Stream_Body_In_Scope
(N : Node_Id;
Decl : Node_Id;
Arr : Entity_Id;
Check : Boolean);
-- 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. indices) 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.
procedure Expand_Fpt_Attribute
(N : Node_Id;
Rtp : Entity_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. Rtp is the root type of the floating
-- point type involved (used to select the proper generic instantiation
-- of the package containing the attribute routines). The Nam argument
-- is the attribute processing routine to be called. This is normally
-- the same as the attribute name, except in the Unaligned_Valid case.
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_Pred_Succ (N : Node_Id);
-- Handles expansion of Pred or Succ attributes for case of non-real
-- operand with overflow checking required.
function Get_Index_Subtype (N : Node_Id) return Entity_Id;
-- Used for Last, Last, and Length, when the prefix is an array type,
-- Obtains the corresponding index subtype.
procedure Expand_Access_To_Type (N : Node_Id);
-- A reference to a type within its own scope is resolved to a reference
-- to the current instance of the type in its initialization procedure.
function Find_Inherited_TSS
(Typ : Entity_Id;
Nam : TSS_Name_Type) return Entity_Id;
-- Returns the TSS of name Nam of Typ, or of its closest ancestor defining
-- such a TSS. Empty is returned is neither Typ nor any of its ancestors
-- have such a TSS.
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 Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean;
-- Utility for array attributes, returns true on packed constrained
-- arrays, and on access to same.
----------------------------------
-- Compile_Stream_Body_In_Scope --
----------------------------------
procedure Compile_Stream_Body_In_Scope
(N : Node_Id;
Decl : Node_Id;
Arr : Entity_Id;
Check : Boolean)
is
Installed : Boolean := False;
Scop : constant Entity_Id := Scope (Arr);
Curr : constant Entity_Id := Current_Scope;
begin
if Is_Hidden (Arr)
and then not In_Open_Scopes (Scop)
and then Ekind (Scop) = E_Package
then
New_Scope (Scop);
Install_Visible_Declarations (Scop);
Install_Private_Declarations (Scop);
Installed := True;
-- 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.
New_Scope (Curr);
end if;
if Check then
Insert_Action (N, Decl);
else
Insert_Action (N, Decl, All_Checks);
end if;
if Installed then
-- Remove extra copy of current scope, and package itself
Pop_Scope;
End_Package_Scope (Scop);
end if;
end Compile_Stream_Body_In_Scope;
---------------------------
-- Expand_Access_To_Type --
---------------------------
procedure Expand_Access_To_Type (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Pref : constant Node_Id := Prefix (N);
Par : Node_Id;
Formal : Entity_Id;
begin
if Is_Entity_Name (Pref)
and then Is_Type (Entity (Pref))
then
-- 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 body 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);
-- The expression must appear in a default expression,
-- (which in the initialization procedure is the rhs 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;
end Expand_Access_To_Type;
--------------------------
-- Expand_Fpt_Attribute --
--------------------------
procedure Expand_Fpt_Attribute
(N : Node_Id;
Rtp : Entity_Id;
Nam : Name_Id;
Args : List_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Pkg : RE_Id;
Fnm : Node_Id;
begin
-- The function name is the selected component Fat_xxx.yyy where xxx
-- is the floating-point root type, 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!
if Rtp = Standard_Short_Float then
Pkg := RE_Fat_Short_Float;
elsif Rtp = Standard_Float then
Pkg := RE_Fat_Float;
elsif Rtp = Standard_Long_Float then
Pkg := RE_Fat_Long_Float;
else
Pkg := RE_Fat_Long_Long_Float;
end if;
Fnm :=
Make_Selected_Component (Loc,
Prefix => New_Reference_To (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,
Unchecked_Convert_To (Etype (N),
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));
Rtp : constant Entity_Id := Root_Type (Etype (E1));
begin
Expand_Fpt_Attribute
(N, Rtp, Attribute_Name (N),
New_List (Unchecked_Convert_To (Rtp, 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));
Rtp : constant Entity_Id := Root_Type (Etype (E1));
E2 : constant Node_Id := Next (E1);
begin
Expand_Fpt_Attribute
(N, Rtp, Attribute_Name (N),
New_List (
Unchecked_Convert_To (Rtp, Relocate_Node (E1)),
Unchecked_Convert_To (Standard_Integer, Relocate_Node (E2))));
end Expand_Fpt_Attribute_RI;
-----------------------------
-- Expand_Fpt_Attribute_RR --
-----------------------------
-- The two arguments is 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));
Rtp : constant Entity_Id := Root_Type (Etype (E1));
E2 : constant Node_Id := Next (E1);
begin
Expand_Fpt_Attribute
(N, Rtp, Attribute_Name (N),
New_List (
Unchecked_Convert_To (Rtp, Relocate_Node (E1)),
Unchecked_Convert_To (Rtp, Relocate_Node (E2))));
end Expand_Fpt_Attribute_RR;
----------------------------------
-- Expand_N_Attribute_Reference --
----------------------------------
procedure Expand_N_Attribute_Reference (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : constant Entity_Id := Etype (N);
Btyp : constant Entity_Id := Base_Type (Typ);
Pref : constant Node_Id := Prefix (N);
Exprs : constant List_Id := Expressions (N);
Id : constant Attribute_Id := Get_Attribute_Id (Attribute_Name (N));
procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id);
-- Rewrites a stream attribute for Read, Write or Output with the
-- procedure call. Pname is the entity for the procedure to call.
------------------------------
-- Rewrite_Stream_Proc_Call --
------------------------------
procedure Rewrite_Stream_Proc_Call (Pname : Entity_Id) is
Item : constant Node_Id := Next (First (Exprs));
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 (Etype (Item)) /= Base_Type (Formal_Typ)
and then Is_Written
then
declare
Temp : constant Entity_Id :=
Make_Defining_Identifier
(Loc, New_Internal_Name ('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
(Etype (Item), 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.
-- For all other cases we do an unchecked conversion of the second
-- parameter to the type of the formal of the procedure we are
-- calling. This deals with the private type cases, and with going
-- to the root type as required in elementary type case.
if not Is_Class_Wide_Type (Entity (Pref))
and then not Is_Class_Wide_Type (Etype (Item))
and then Base_Type (Etype (Item)) /= Base_Type (Formal_Typ)
then
Rewrite (Item,
Unchecked_Convert_To (Formal_Typ, Relocate_Node (Item)));
-- 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;
-- 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_Stream_Proc_Call;
-- Start of processing for Expand_N_Attribute_Reference
begin
-- Do required validity checking
if Validity_Checks_On and Validity_Check_Operands then
declare
Expr : Node_Id;
begin
Expr := First (Expressions (N));
while Present (Expr) loop
Ensure_Valid (Expr);
Next (Expr);
end loop;
end;
end if;
-- Remaining processing depends on specific attribute
case Id is
------------
-- Access --
------------
when Attribute_Access =>
if Ekind (Btyp) = E_Access_Protected_Subprogram_Type then
-- 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 a selected component.
declare
Agg : Node_Id;
Sub : Entity_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;
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
pragma Assert (In_Open_Scopes (Scope (Entity (Pref))));
Sub :=
New_Occurrence_Of
(Protected_Body_Subprogram (Entity (Pref)), Loc);
Curr := Current_Scope;
while Scope (Curr) /= Scope (Entity (Pref)) loop
Curr := Scope (Curr);
end loop;
Obj_Ref :=
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(First_Formal
(Protected_Body_Subprogram (Curr)), Loc),
Attribute_Name => Name_Address);
-- 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;
Agg :=
Make_Aggregate (Loc,
Expressions =>
New_List (
Obj_Ref,
Unchecked_Convert_To (Acc,
Make_Attribute_Reference (Loc,
Prefix => Sub,
Attribute_Name => Name_Address))));
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;
elsif Ekind (Btyp) = E_General_Access_Type then
declare
Ref_Object : constant Node_Id := Get_Referenced_Object (Pref);
Parm_Ent : Entity_Id;
Conversion : Node_Id;
begin
-- If the prefix of an Access attribute is a dereference of an
-- access parameter (or a renaming of such a dereference) and
-- the context is a general access type (but not an anonymous
-- access type), then rewrite the attribute as a conversion of
-- the access parameter to the context access type. This will
-- result in an accessibility check being performed, if needed.
-- (X.all'Access => Acc_Type (X))
if Nkind (Ref_Object) = N_Explicit_Dereference
and then Is_Entity_Name (Prefix (Ref_Object))
then
Parm_Ent := Entity (Prefix (Ref_Object));
if Ekind (Parm_Ent) in Formal_Kind
and then Ekind (Etype (Parm_Ent)) = E_Anonymous_Access_Type
and then Present (Extra_Accessibility (Parm_Ent))
then
Conversion :=
Convert_To (Typ, New_Copy_Tree (Prefix (Ref_Object)));
Rewrite (N, Conversion);
Analyze_And_Resolve (N, Typ);
end if;
end if;
end;
-- If the prefix is a type name, this is a reference to the current
-- instance of the type, within its initialization procedure.
else
Expand_Access_To_Type (N);
end if;
--------------
-- 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;
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 (Etype (Pref)));
while Present (Task_Proc) loop
exit when Ekind (Task_Proc) = E_Procedure
and then Etype (First_Formal (Task_Proc)) =
Corresponding_Record_Type (Etype (Pref));
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 (Etype (Pref)) = E_Subprogram_Type
and then Convention (Etype (Pref)) = 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;
end if;
-- Deal with packed array reference, other cases are handled by gigi
if Involves_Packed_Array_Reference (Pref) then
Expand_Packed_Address_Reference (N);
end if;
end Address;
---------------
-- Alignment --
---------------
when Attribute_Alignment => Alignment : declare
Ptyp : constant Entity_Id := Etype (Pref);
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_Function_Call (Loc,
Name => New_Reference_To
(Find_Prim_Op (Ptyp, Name_uAlignment), Loc),
Parameter_Associations => New_List (Pref));
if Typ /= Standard_Integer then
-- The context is a specific integer type with which the
-- original attribute was compatible. The function has a
-- specific type as well, so to preserve the compatibility
-- we must convert explicitly.
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;
---------------
-- AST_Entry --
---------------
when Attribute_AST_Entry => AST_Entry : declare
Ttyp : Entity_Id;
T_Id : Node_Id;
Eent : Entity_Id;
Entry_Ref : Node_Id;
-- The reference to the entry or entry family
Index : Node_Id;
-- The index expression for an entry family reference, or
-- the Empty if Entry_Ref references a simple entry.
begin
if Nkind (Pref) = N_Indexed_Component then
Entry_Ref := Prefix (Pref);
Index := First (Expressions (Pref));
else
Entry_Ref := Pref;
Index := Empty;
end if;
-- Get expression for Task_Id and the entry entity
if Nkind (Entry_Ref) = N_Selected_Component then
T_Id :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Identity,
Prefix => Prefix (Entry_Ref));
Ttyp := Etype (Prefix (Entry_Ref));
Eent := Entity (Selector_Name (Entry_Ref));
else
T_Id :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Current_Task), Loc));
Eent := Entity (Entry_Ref);
-- We have to find the enclosing task to get the task type
-- There must be one, since we already validated this earlier
Ttyp := Current_Scope;
while not Is_Task_Type (Ttyp) loop
Ttyp := Scope (Ttyp);
end loop;
end if;
-- Now rewrite the attribute with a call to Create_AST_Handler
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Create_AST_Handler), Loc),
Parameter_Associations => New_List (
T_Id,
Entry_Index_Expression (Loc, Eent, Index, Ttyp))));
Analyze_And_Resolve (N, RTE (RE_AST_Handler));
end AST_Entry;
------------------
-- Bit_Position --
------------------
-- We compute this if a component clause was present, otherwise
-- we leave the computation up to Gigi, since we don't know what
-- layout will be chosen.
-- Note that the attribute can apply to a naked record component
-- in generated code (i.e. the prefix is an identifier that
-- references the component or discriminant entity).
when Attribute_Bit_Position => Bit_Position :
declare
CE : Entity_Id;
begin
if Nkind (Pref) = N_Identifier then
CE := Entity (Pref);
else
CE := Entity (Selector_Name (Pref));
end if;
if Known_Static_Component_Bit_Offset (CE) then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Component_Bit_Offset (CE)));
Analyze_And_Resolve (N, Typ);
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Bit_Position;
------------------
-- 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
-- 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_Defining_Identifier (Loc, New_Internal_Name ('V'));
Pent : Entity_Id := Entity (Pref);
S : String_Id;
begin
-- If not library unit, get to containing library unit
while Pent /= Standard_Standard
and then Scope (Pent) /= Standard_Standard
loop
Pent := Scope (Pent);
end loop;
-- Special case Standard
if Pent = Standard_Standard
or else Pent = Standard_ASCII
then
Name_Buffer (1 .. Verbose_Library_Version'Length) :=
Verbose_Library_Version;
Name_Len := Verbose_Library_Version'Length;
Rewrite (N,
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer));
-- 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));
-- And now rewrite original reference
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (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 => Callable :
begin
Rewrite (N,
Build_Call_With_Task (Pref, RTE (RE_Callable)));
Analyze_And_Resolve (N, Standard_Boolean);
end Callable;
------------
-- 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 : Integer := 0;
Name : Node_Id;
S : Entity_Id;
begin
-- Protected case
if Is_Protected_Type (Conctype) then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Conctype) > 1
then
Name :=
New_Reference_To
(RTE (RE_Protected_Entry_Caller), Loc);
else
Name :=
New_Reference_To
(RTE (RE_Protected_Single_Entry_Caller), Loc);
end if;
Rewrite (N,
Unchecked_Convert_To (Id_Kind,
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List
(New_Reference_To (
Object_Ref
(Corresponding_Body (Parent (Conctype))), 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_Reference_To (
RTE (RE_Task_Entry_Caller), Loc),
Parameter_Associations => New_List (
Make_Integer_Literal (Loc,
Intval => Int (Nest_Depth))))));
end if;
Analyze_And_Resolve (N, Id_Kind);
end Caller;
-------------
-- 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), Sloc (N)));
-- 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)), Sloc (N)));
-- For all other entity names, we can tell at compile time
elsif Is_Entity_Name (Pref) then
declare
Ent : constant Entity_Id := Entity (Pref);
Res : Boolean;
begin
-- (RM J.4) obsolescent cases
if Is_Type (Ent) then
-- Private type
if Is_Private_Type (Ent) then
Res := not Has_Discriminants (Ent)
or else Is_Constrained (Ent);
-- It not a private type, must be a generic actual type
-- that corresponded to a private type. We know that this
-- correspondence holds, since otherwise the reference
-- within the generic template would have been illegal.
else
if Is_Composite_Type (Underlying_Type (Ent)) then
Res := Is_Constrained (Ent);
else
Res := True;
end if;
end if;
-- If the prefix is not a variable or is aliased, then
-- definitely true; if it's a formal parameter without
-- an associated extra formal, then treat it as constrained.
elsif not Is_Variable (Pref)
or else Present (Formal_Ent)
or else Is_Aliased_View (Pref)
then
Res := True;
-- Variable case, just look at type to see if it is
-- constrained. Note that the one case where this is
-- not accurate (the procedure formal case), has been
-- handled above.
else
Res := Is_Constrained (Etype (Ent));
end if;
if Res then
Rewrite (N,
New_Reference_To (Standard_True, Loc));
else
Rewrite (N,
New_Reference_To (Standard_False, Loc));
end if;
end;
-- Prefix is not an entity name. These are also cases where
-- we can always tell at compile time by looking at the form
-- and type of the prefix.
else
if not Is_Variable (Pref)
or else Nkind (Pref) = N_Explicit_Dereference
or else Is_Constrained (Etype (Pref))
then
Rewrite (N,
New_Reference_To (Standard_True, Loc));
else
Rewrite (N,
New_Reference_To (Standard_False, Loc));
end if;
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
Entnam : Node_Id;
Index : Node_Id;
Name : Node_Id;
Call : Node_Id;
Conctyp : Entity_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;
-- 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
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Conctyp) > 1
then
Name := New_Reference_To (RTE (RE_Protected_Count), Loc);
Call :=
Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Reference_To (
Object_Ref (
Corresponding_Body (Parent (Conctyp))), Loc),
Entry_Index_Expression (
Loc, Entity (Entnam), Index, Scope (Entity (Entnam)))));
else
Name := New_Reference_To (RTE (RE_Protected_Count_Entry), Loc);
Call := Make_Function_Call (Loc,
Name => Name,
Parameter_Associations => New_List (
New_Reference_To (
Object_Ref (
Corresponding_Body (Parent (Conctyp))), Loc)));
end if;
-- Task case
else
Call :=
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Task_Count), Loc),
Parameter_Associations => New_List (
Entry_Index_Expression
(Loc, Entity (Entnam), Index, Scope (Entity (Entnam)))));
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;
---------------
-- 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 =>
Elab_Body : declare
Ent : constant Entity_Id :=
Make_Defining_Identifier (Loc,
New_Internal_Name ('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.
procedure Make_Elab_String (Nod : Node_Id) is
begin
if Nkind (Nod) = N_Selected_Component then
Make_Elab_String (Prefix (Nod));
if Java_VM then
Store_String_Char ('$');
else
Store_String_Char ('_');
Store_String_Char ('_');
end if;
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);
if Java_VM then
Store_String_Chars ("._elab");
Lang := Make_Identifier (Loc, Name_Ada);
else
Store_String_Chars ("___elab");
Lang := Make_Identifier (Loc, Name_C);
end if;
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;
----------------
-- 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 through to Gigi
when Attribute_Elaborated => Elaborated : declare
Ent : constant Entity_Id := Entity (Pref);
begin
if Present (Elaboration_Entity (Ent)) then
Rewrite (N,
New_Occurrence_Of (Elaboration_Entity (Ent), Loc));
else
Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
end if;
end Elaborated;
--------------
-- Enum_Rep --
--------------
when Attribute_Enum_Rep => Enum_Rep :
begin
-- X'Enum_Rep (Y) expands to
-- target-type (Y)
-- This is simply a direct conversion from the enumeration type
-- to the target integer type, which is treated by Gigi as a normal
-- integer conversion, treating the enumeration type as an integer,
-- which is exactly what we want! We set Conversion_OK to make sure
-- that the analyzer does not complain about what otherwise might
-- be an illegal conversion.
if Is_Non_Empty_List (Exprs) then
Rewrite (N,
OK_Convert_To (Typ, Relocate_Node (First (Exprs))));
-- X'Enum_Rep where X is an enumeration literal is replaced by
-- the literal value.
elsif Ekind (Entity (Pref)) = E_Enumeration_Literal then
Rewrite (N,
Make_Integer_Literal (Loc, Enumeration_Rep (Entity (Pref))));
-- If this is a renaming of a literal, recover the representation
-- of the original.
elsif Ekind (Entity (Pref)) = E_Constant
and then Present (Renamed_Object (Entity (Pref)))
and then
Ekind (Entity (Renamed_Object (Entity (Pref))))
= E_Enumeration_Literal
then
Rewrite (N,
Make_Integer_Literal (Loc,
Enumeration_Rep (Entity (Renamed_Object (Entity (Pref))))));
-- X'Enum_Rep where X is an object does a direct unchecked conversion
-- of the object value, as described for the type case above.
else
Rewrite (N,
OK_Convert_To (Typ, Relocate_Node (Pref)));
end if;
Set_Etype (N, Typ);
Analyze_And_Resolve (N, Typ);
end Enum_Rep;
--------------
-- 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 => External_Tag :
begin
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (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);
end External_Tag;
-----------
-- First --
-----------
when Attribute_First => declare
Ptyp : constant Entity_Id := Etype (Pref);
begin
-- If the prefix type is a constrained packed array type which
-- already has a Packed_Array_Type representation defined, then
-- replace this attribute with a direct reference to 'First of the
-- appropriate index subtype (since otherwise Gigi will try to give
-- us the value of 'First for this implementation type).
if Is_Constrained_Packed_Array (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
Analyze_And_Resolve (N, Typ);
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
end if;
end;
---------------
-- First_Bit --
---------------
-- We compute this if a component clause was present, otherwise
-- we leave the computation up to Gigi, since we don't know what
-- layout will be chosen.
when Attribute_First_Bit => First_Bit :
declare
CE : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Known_Static_Component_Bit_Offset (CE) then
Rewrite (N,
Make_Integer_Literal (Loc,
Component_Bit_Offset (CE) mod System_Storage_Unit));
Analyze_And_Resolve (N, Typ);
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end First_Bit;
-----------------
-- Fixed_Value --
-----------------
-- We transform:
-- fixtype'Fixed_Value (integer-value)
-- into
-- fixtype(integer-value)
-- we do all the required analysis of the conversion here, because
-- we do not want this to go through the fixed-point conversion
-- circuits. Note that gigi always treats fixed-point as equivalent
-- to the corresponding integer type anyway.
when Attribute_Fixed_Value => Fixed_Value :
begin
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
Expression => Relocate_Node (First (Exprs))));
Set_Etype (N, Entity (Pref));
Set_Analyzed (N);
-- Note: 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 call are critical!
Apply_Type_Conversion_Checks (N);
end Fixed_Value;
-----------
-- 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
-- Result_Type (System.Fore (Long_Long_Float (Type'First)),
-- Long_Long_Float (Type'Last))
-- Note that we know that the type is a non-static subtype, or Fore
-- would have itself been computed dynamically in Eval_Attribute.
when Attribute_Fore => Fore :
declare
Ptyp : constant Entity_Id := Etype (Pref);
begin
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Fore), Loc),
Parameter_Associations => New_List (
Convert_To (Standard_Long_Long_Float,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ptyp, Loc),
Attribute_Name => Name_First)),
Convert_To (Standard_Long_Long_Float,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ptyp, Loc),
Attribute_Name => Name_Last))))));
Analyze_And_Resolve (N, Typ);
end Fore;
--------------
-- Fraction --
--------------
-- Transforms 'Fraction into a call to the floating-point attribute
-- function Fraction in Fat_xxx (where xxx is the root type)
when Attribute_Fraction =>
Expand_Fpt_Attribute_R (N);
--------------
-- Identity --
--------------
-- For an exception returns a reference to the exception data:
-- Exception_Id!(Prefix'Reference)
-- For a task it returns a reference to the _task_id component of
-- corresponding record:
-- taskV!(Prefix)._Task_Id, converted to the type Task_ID defined
-- in Ada.Task_Identification.
when Attribute_Identity => Identity : declare
Id_Kind : Entity_Id;
begin
if Etype (Pref) = Standard_Exception_Type then
Id_Kind := RTE (RE_Exception_Id);
if Present (Renamed_Object (Entity (Pref))) then
Set_Entity (Pref, Renamed_Object (Entity (Pref)));
end if;
Rewrite (N,
Unchecked_Convert_To (Id_Kind, Make_Reference (Loc, Pref)));
else
Id_Kind := RTE (RO_AT_Task_ID);
Rewrite (N,
Unchecked_Convert_To (Id_Kind, Concurrent_Ref (Pref)));
end if;
Analyze_And_Resolve (N, Id_Kind);
end Identity;
-----------
-- Image --
-----------
-- Image attribute is handled in separate unit Exp_Imgv
when Attribute_Image =>
Exp_Imgv.Expand_Image_Attribute (N);
---------
-- Img --
---------
-- X'Img is expanded to typ'Image (X), where typ is the type of X
when Attribute_Img => Img :
begin
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Etype (Pref), Loc),
Attribute_Name => Name_Image,
Expressions => New_List (Relocate_Node (Pref))));
Analyze_And_Resolve (N, Standard_String);
end Img;
-----------
-- Input --
-----------
when Attribute_Input => Input : declare
P_Type : constant Entity_Id := Entity (Pref);
B_Type : constant Entity_Id := Base_Type (P_Type);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Strm : constant Node_Id := First (Exprs);
Fname : Entity_Id;
Decl : Node_Id;
Call : Node_Id;
Prag : Node_Id;
Arg2 : Node_Id;
Rfunc : Node_Id;
Cntrl : Node_Id := Empty;
-- Value for controlling argument in call. Always Empty except in
-- the dispatching (class-wide type) case, where it is a reference
-- to the dummy object initialized to the right internal tag.
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- If there is a TSS for Input, just call it
Fname := Find_Stream_Subprogram (P_Type, TSS_Stream_Input);
if Present (Fname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Input (stream)
-- as
-- sourcetyp (streamread (strmtyp'Input (stream)));
-- where stmrearead is the given Read function that converts
-- an argument of type strmtyp to type sourcetyp or a type
-- from which it is derived. The extra conversion is required
-- for the derived case.
Prag :=
Get_Rep_Pragma
(Implementation_Base_Type (P_Type), Name_Stream_Convert);
if Present (Prag) then
Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
Rfunc := Entity (Expression (Arg2));
Rewrite (N,
Convert_To (B_Type,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Rfunc, Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(Etype (First_Formal (Rfunc)), Loc),
Attribute_Name => Name_Input,
Expressions => Exprs)))));
Analyze_And_Resolve (N, B_Type);
return;
-- Elementary types
elsif Is_Elementary_Type (U_Type) then
-- A special case arises if we have a defined _Read routine,
-- since in this case we are required to call this routine.
if Present (TSS (Base_Type (U_Type), TSS_Stream_Read)) then
Build_Record_Or_Elementary_Input_Function
(Loc, U_Type, Decl, Fname);
Insert_Action (N, Decl);
-- For normal cases, we call the I_xxx routine directly
else
Rewrite (N, Build_Elementary_Input_Call (N));
Analyze_And_Resolve (N, P_Type);
return;
end if;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Input_Function (Loc, U_Type, Decl, Fname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Dispatching case with class-wide type
elsif Is_Class_Wide_Type (P_Type) then
declare
Rtyp : constant Entity_Id := Root_Type (P_Type);
Dnn : Entity_Id;
Decl : Node_Id;
begin
-- Read the internal tag (RM 13.13.2(34)) and use it to
-- initialize a dummy tag object:
-- Dnn : Ada.Tags.Tag
-- := Internal_Tag (String'Input (Strm));
-- This dummy object is used only to provide a controlling
-- argument for the eventual _Input call.
Dnn :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('D'));
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Dnn,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Tag), Loc),
Expression =>
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Internal_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Standard_String, Loc),
Attribute_Name => Name_Input,
Expressions => New_List (
Relocate_Node
(Duplicate_Subexpr (Strm)))))));
Insert_Action (N, Decl);
-- Now we need to get the entity for the call, and construct
-- a function call node, where we preset a reference to Dnn
-- as the controlling argument (doing an unchecked
-- conversion to the classwide tagged type to make it
-- look like a real tagged object).
Fname := Find_Prim_Op (Rtyp, TSS_Stream_Input);
Cntrl := Unchecked_Convert_To (P_Type,
New_Occurrence_Of (Dnn, Loc));
Set_Etype (Cntrl, P_Type);
Set_Parent (Cntrl, N);
end;
-- For tagged types, use the primitive Input function
elsif Is_Tagged_Type (U_Type) then
Fname := Find_Prim_Op (U_Type, TSS_Stream_Input);
-- All other record type cases, including protected records.
-- The latter only arise for expander generated code for
-- handling shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
Build_Record_Or_Elementary_Input_Function
(Loc, Base_Type (U_Type), Decl, Fname);
Insert_Action (N, Decl);
end if;
end if;
-- If we fall through, Fname is the function to be called. The
-- result is obtained by calling the appropriate function, then
-- converting the result. The conversion does a subtype check.
Call :=
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Fname, Loc),
Parameter_Associations => New_List (
Relocate_Node (Strm)));
Set_Controlling_Argument (Call, Cntrl);
Rewrite (N, Unchecked_Convert_To (P_Type, Call));
Analyze_And_Resolve (N, P_Type);
end Input;
-------------------
-- Integer_Value --
-------------------
-- We transform
-- inttype'Fixed_Value (fixed-value)
-- into
-- inttype(integer-value))
-- we do all the required analysis of the conversion here, because
-- we do not want this to go through the fixed-point conversion
-- circuits. Note that gigi always treats fixed-point as equivalent
-- to the corresponding integer type anyway.
when Attribute_Integer_Value => Integer_Value :
begin
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Occurrence_Of (Entity (Pref), Loc),
Expression => Relocate_Node (First (Exprs))));
Set_Etype (N, Entity (Pref));
Set_Analyzed (N);
-- Note: 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 call are critical!
Apply_Type_Conversion_Checks (N);
end Integer_Value;
----------
-- Last --
----------
when Attribute_Last => declare
Ptyp : constant Entity_Id := Etype (Pref);
begin
-- If the prefix type is a constrained packed array type which
-- already has a Packed_Array_Type representation defined, then
-- replace this attribute with a direct reference to 'Last of the
-- appropriate index subtype (since otherwise Gigi will try to give
-- us the value of 'Last for this implementation type).
if Is_Constrained_Packed_Array (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Reference_To (Get_Index_Subtype (N), Loc)));
Analyze_And_Resolve (N, Typ);
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
end if;
end;
--------------
-- Last_Bit --
--------------
-- We compute this if a component clause was present, otherwise
-- we leave the computation up to Gigi, since we don't know what
-- layout will be chosen.
when Attribute_Last_Bit => Last_Bit :
declare
CE : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Known_Static_Component_Bit_Offset (CE)
and then Known_Static_Esize (CE)
then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => (Component_Bit_Offset (CE) mod System_Storage_Unit)
+ Esize (CE) - 1));
Analyze_And_Resolve (N, Typ);
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Last_Bit;
------------------
-- Leading_Part --
------------------
-- Transforms 'Leading_Part into a call to the floating-point attribute
-- function Leading_Part in Fat_xxx (where xxx is the root type)
-- Note: strictly, we should have special case code to deal with
-- absurdly large positive arguments (greater than Integer'Last),
-- which result in returning the first argument unchanged, but it
-- hardly seems worth the effort. We raise constraint error for
-- absurdly negative arguments which is fine.
when Attribute_Leading_Part =>
Expand_Fpt_Attribute_RI (N);
------------
-- Length --
------------
when Attribute_Length => declare
Ptyp : constant Entity_Id := Etype (Pref);
Ityp : Entity_Id;
Xnum : Uint;
begin
-- Processing for packed array types
if Is_Array_Type (Ptyp) and then Is_Packed (Ptyp) then
Ityp := Get_Index_Subtype (N);
-- If the index type, Ityp, is an enumeration type with
-- holes, then we calculate X'Length explicitly using
-- Typ'Max
-- (0, Ityp'Pos (X'Last (N)) -
-- Ityp'Pos (X'First (N)) + 1);
-- Since the bounds in the template are the representation
-- values and gigi would get the wrong value.
if Is_Enumeration_Type (Ityp)
and then Present (Enum_Pos_To_Rep (Base_Type (Ityp)))
then
if No (Exprs) then
Xnum := Uint_1;
else
Xnum := Expr_Value (First (Expressions (N)));
end if;
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Typ, Loc),
Attribute_Name => Name_Max,
Expressions => New_List
(Make_Integer_Literal (Loc, 0),
Make_Op_Add (Loc,
Left_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ityp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Pref),
Attribute_Name => Name_Last,
Expressions => New_List (
Make_Integer_Literal (Loc, Xnum))))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ityp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr_No_Checks (Pref),
Attribute_Name => Name_First,
Expressions => New_List (
Make_Integer_Literal (Loc, Xnum)))))),
Right_Opnd => Make_Integer_Literal (Loc, 1)))));
Analyze_And_Resolve (N, Typ, Suppress => All_Checks);
return;
-- If the prefix type is a constrained packed array type which
-- already has a Packed_Array_Type representation defined, then
-- replace this attribute with a direct reference to 'Range_Length
-- of the appropriate index subtype (since otherwise Gigi will try
-- to give us the value of 'Length for this implementation type).
elsif Is_Constrained (Ptyp) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Range_Length,
Prefix => New_Reference_To (Ityp, Loc)));
Analyze_And_Resolve (N, Typ);
end if;
-- If we have a packed array that is not bit packed, which was
-- Access type case
elsif Is_Access_Type (Ptyp) then
Apply_Access_Check (N);
-- If the designated type is a packed array type, then we
-- convert the reference to:
-- typ'Max (0, 1 +
-- xtyp'Pos (Pref'Last (Expr)) -
-- xtyp'Pos (Pref'First (Expr)));
-- This is a bit complex, but it is the easiest thing to do
-- that works in all cases including enum types with holes
-- xtyp here is the appropriate index type.
declare
Dtyp : constant Entity_Id := Designated_Type (Ptyp);
Xtyp : Entity_Id;
begin
if Is_Array_Type (Dtyp) and then Is_Packed (Dtyp) then
Xtyp := Get_Index_Subtype (N);
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Typ, Loc),
Attribute_Name => Name_Max,
Expressions => New_List (
Make_Integer_Literal (Loc, 0),
Make_Op_Add (Loc,
Make_Integer_Literal (Loc, 1),
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Xtyp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => Duplicate_Subexpr (Pref),
Attribute_Name => Name_Last,
Expressions =>
New_Copy_List (Exprs)))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Xtyp, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Duplicate_Subexpr_No_Checks (Pref),
Attribute_Name => Name_First,
Expressions =>
New_Copy_List (Exprs)))))))));
Analyze_And_Resolve (N, Typ);
end if;
end;
-- Otherwise leave it to gigi
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end;
-------------
-- Machine --
-------------
-- Transforms 'Machine into a call to the floating-point attribute
-- function Machine in Fat_xxx (where xxx is the root type)
when Attribute_Machine =>
Expand_Fpt_Attribute_R (N);
------------------
-- Machine_Size --
------------------
-- Machine_Size is equivalent to Object_Size, so transform it into
-- Object_Size and that way Gigi never sees Machine_Size.
when Attribute_Machine_Size =>
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Prefix (N),
Attribute_Name => Name_Object_Size));
Analyze_And_Resolve (N, Typ);
--------------
-- Mantissa --
--------------
-- The only case that can get this far is the dynamic case of the
-- old Ada 83 Mantissa attribute for the fixed-point case. For this
-- case, we expand:
-- typ'Mantissa
-- into
-- ityp (System.Mantissa.Mantissa_Value
-- (Integer'Integer_Value (typ'First),
-- Integer'Integer_Value (typ'Last)));
when Attribute_Mantissa => Mantissa : declare
Ptyp : constant Entity_Id := Etype (Pref);
begin
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Mantissa_Value), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_Integer, Loc),
Attribute_Name => Name_Integer_Value,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_First))),
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_Integer, Loc),
Attribute_Name => Name_Integer_Value,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_Last)))))));
Analyze_And_Resolve (N, Typ);
end Mantissa;
-----------
-- Model --
-----------
-- Transforms 'Model into a call to the floating-point attribute
-- function Model in Fat_xxx (where xxx is the root type)
when Attribute_Model =>
Expand_Fpt_Attribute_R (N);
-----------------
-- Object_Size --
-----------------
-- The processing for Object_Size shares the processing for Size
------------
-- Output --
------------
when Attribute_Output => Output : declare
P_Type : constant Entity_Id := Entity (Pref);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Pname : Entity_Id;
Decl : Node_Id;
Prag : Node_Id;
Arg3 : Node_Id;
Wfunc : Node_Id;
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- If TSS for Output is present, just call it
Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Output);
if Present (Pname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Output (stream, Item)
-- as
-- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
-- where strmwrite is the given Write function that converts
-- an argument of type sourcetyp or a type acctyp, from which
-- it is derived to type strmtyp. The conversion to acttyp is
-- required for the derived case.
Prag :=
Get_Rep_Pragma
(Implementation_Base_Type (P_Type), Name_Stream_Convert);
if Present (Prag) then
Arg3 :=
Next (Next (First (Pragma_Argument_Associations (Prag))));
Wfunc := Entity (Expression (Arg3));
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
Attribute_Name => Name_Output,
Expressions => New_List (
Relocate_Node (First (Exprs)),
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Wfunc, Loc),
Parameter_Associations => New_List (
Convert_To (Etype (First_Formal (Wfunc)),
Relocate_Node (Next (First (Exprs)))))))));
Analyze (N);
return;
-- For elementary types, we call the W_xxx routine directly.
-- Note that the effect of Write and Output is identical for
-- the case of an elementary type, since there are no
-- discriminants or bounds.
elsif Is_Elementary_Type (U_Type) then
-- A special case arises if we have a defined _Write routine,
-- since in this case we are required to call this routine.
if Present (TSS (Base_Type (U_Type), TSS_Stream_Write)) then
Build_Record_Or_Elementary_Output_Procedure
(Loc, U_Type, Decl, Pname);
Insert_Action (N, Decl);
-- For normal cases, we call the W_xxx routine directly
else
Rewrite (N, Build_Elementary_Write_Call (N));
Analyze (N);
return;
end if;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Output_Procedure (Loc, U_Type, Decl, Pname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Class-wide case, first output external tag, then dispatch
-- to the appropriate primitive Output function (RM 13.13.2(31)).
elsif Is_Class_Wide_Type (P_Type) then
Tag_Write : declare
Strm : constant Node_Id := First (Exprs);
Item : constant Node_Id := Next (Strm);
begin
-- The code is:
-- String'Output (Strm, External_Tag (Item'Tag))
Insert_Action (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Standard_String, Loc),
Attribute_Name => Name_Output,
Expressions => New_List (
Relocate_Node (Duplicate_Subexpr (Strm)),
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_External_Tag), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Relocate_Node
(Duplicate_Subexpr (Item, Name_Req => True)),
Attribute_Name => Name_Tag))))));
end Tag_Write;
Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
-- Tagged type case, use the primitive Output function
elsif Is_Tagged_Type (U_Type) then
Pname := Find_Prim_Op (U_Type, TSS_Stream_Output);
-- All other record type cases, including protected records.
-- The latter only arise for expander generated code for
-- handling shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
Build_Record_Or_Elementary_Output_Procedure
(Loc, Base_Type (U_Type), Decl, Pname);
Insert_Action (N, Decl);
end if;
end if;
-- If we fall through, Pname is the name of the procedure to call
Rewrite_Stream_Proc_Call (Pname);
end Output;
---------
-- Pos --
---------
-- For enumeration types with a standard representation, Pos is
-- handled by Gigi.
-- For enumeration types, with a non-standard representation we
-- generate a call to the _Rep_To_Pos function created when the
-- type was frozen. The call has the form
-- _rep_to_pos (expr, flag)
-- The parameter flag is True if range checks are enabled, causing
-- Program_Error to be raised if the expression has an invalid
-- representation, and False if range checks are suppressed.
-- For integer types, Pos is equivalent to a simple integer
-- conversion and we rewrite it as such
when Attribute_Pos => Pos :
declare
Etyp : Entity_Id := Base_Type (Entity (Pref));
begin
-- Deal with zero/non-zero boolean values
if Is_Boolean_Type (Etyp) then
Adjust_Condition (First (Exprs));
Etyp := Standard_Boolean;
Set_Prefix (N, New_Occurrence_Of (Standard_Boolean, Loc));
end if;
-- Case of enumeration type
if Is_Enumeration_Type (Etyp) then
-- Non-standard enumeration type (generate call)
if Present (Enum_Pos_To_Rep (Etyp)) then
Append_To (Exprs, Rep_To_Pos_Flag (Etyp, Loc));
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Reference_To (TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => Exprs)));
Analyze_And_Resolve (N, Typ);
-- Standard enumeration type (do universal integer check)
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
-- Deal with integer types (replace by conversion)
elsif Is_Integer_Type (Etyp) then
Rewrite (N, Convert_To (Typ, First (Exprs)));
Analyze_And_Resolve (N, Typ);
end if;
end Pos;
--------------
-- Position --
--------------
-- We compute this if a component clause was present, otherwise
-- we leave the computation up to Gigi, since we don't know what
-- layout will be chosen.
when Attribute_Position => Position :
declare
CE : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Present (Component_Clause (CE)) then
Rewrite (N,
Make_Integer_Literal (Loc,
Intval => Component_Bit_Offset (CE) / System_Storage_Unit));
Analyze_And_Resolve (N, Typ);
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Position;
----------
-- Pred --
----------
-- 1. Deal with enumeration types with holes
-- 2. For floating-point, generate call to attribute function
-- 3. For other cases, deal with constraint checking
when Attribute_Pred => Pred :
declare
Ptyp : constant Entity_Id := Base_Type (Etype (Pref));
begin
-- For enumeration types with non-standard representations, we
-- expand typ'Pred (x) into
-- Pos_To_Rep (Rep_To_Pos (x) - 1)
-- If the representation is contiguous, we compute instead
-- Lit1 + Rep_to_Pos (x -1), to catch invalid representations.
if Is_Enumeration_Type (Ptyp)
and then Present (Enum_Pos_To_Rep (Ptyp))
then
if Has_Contiguous_Rep (Ptyp) then
Rewrite (N,
Unchecked_Convert_To (Ptyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Ptyp))),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Ptyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations =>
New_List (
Unchecked_Convert_To (Ptyp,
Make_Op_Subtract (Loc,
Left_Opnd =>
Unchecked_Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))),
Right_Opnd =>
Make_Integer_Literal (Loc, 1))),
Rep_To_Pos_Flag (Ptyp, Loc))))));
else
-- Add Boolean parameter True, to request program errror if
-- we have a bad representation on our hands. If checks are
-- suppressed, then add False instead
Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Enum_Pos_To_Rep (Ptyp), Loc),
Expressions => New_List (
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To (TSS (Ptyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => Exprs),
Right_Opnd => Make_Integer_Literal (Loc, 1)))));
end if;
Analyze_And_Resolve (N, Typ);
-- For floating-point, we transform 'Pred into a call to the Pred
-- floating-point attribute function in Fat_xxx (xxx is root type)
elsif Is_Floating_Point_Type (Ptyp) then
Expand_Fpt_Attribute_R (N);
Analyze_And_Resolve (N, Typ);
-- For modular types, nothing to do (no overflow, since wraps)
elsif Is_Modular_Integer_Type (Ptyp) then
null;
-- For other types, if range checking is enabled, we must generate
-- a check if overflow checking is enabled.
elsif not Overflow_Checks_Suppressed (Ptyp) then
Expand_Pred_Succ (N);
end if;
end Pred;
------------------
-- Range_Length --
------------------
when Attribute_Range_Length => Range_Length : declare
P_Type : constant Entity_Id := Etype (Pref);
begin
-- The only special processing required is for the case where
-- Range_Length is applied to an enumeration type with holes.
-- In this case we transform
-- X'Range_Length
-- to
-- X'Pos (X'Last) - X'Pos (X'First) + 1
-- So that the result reflects the proper Pos values instead
-- of the underlying representations.
if Is_Enumeration_Type (P_Type)
and then Has_Non_Standard_Rep (P_Type)
then
Rewrite (N,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (P_Type, Loc),
Expressions => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Occurrence_Of (P_Type, Loc)))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (P_Type, Loc),
Expressions => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Occurrence_Of (P_Type, Loc))))),
Right_Opnd =>
Make_Integer_Literal (Loc, 1)));
Analyze_And_Resolve (N, Typ);
-- For all other cases, attribute is handled by Gigi, but we need
-- to deal with the case of the range check on a universal integer.
else
Apply_Universal_Integer_Attribute_Checks (N);
end if;
end Range_Length;
----------
-- Read --
----------
when Attribute_Read => Read : declare
P_Type : constant Entity_Id := Entity (Pref);
B_Type : constant Entity_Id := Base_Type (P_Type);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Pname : Entity_Id;
Decl : Node_Id;
Prag : Node_Id;
Arg2 : Node_Id;
Rfunc : Node_Id;
Lhs : Node_Id;
Rhs : Node_Id;
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- The simple case, if there is a TSS for Read, just call it
Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Read);
if Present (Pname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Read (stream, Item)
-- as
-- Item := sourcetyp (strmread (strmtyp'Input (Stream)));
-- where strmread is the given Read function that converts
-- an argument of type strmtyp to type sourcetyp or a type
-- from which it is derived. The conversion to sourcetyp
-- is required in the latter case.
-- A special case arises if Item is a type conversion in which
-- case, we have to expand to:
-- Itemx := typex (strmread (strmtyp'Input (Stream)));
-- where Itemx is the expression of the type conversion (i.e.
-- the actual object), and typex is the type of Itemx.
Prag :=
Get_Rep_Pragma
(Implementation_Base_Type (P_Type), Name_Stream_Convert);
if Present (Prag) then
Arg2 := Next (First (Pragma_Argument_Associations (Prag)));
Rfunc := Entity (Expression (Arg2));
Lhs := Relocate_Node (Next (First (Exprs)));
Rhs :=
Convert_To (B_Type,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Rfunc, Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of
(Etype (First_Formal (Rfunc)), Loc),
Attribute_Name => Name_Input,
Expressions => New_List (
Relocate_Node (First (Exprs)))))));
if Nkind (Lhs) = N_Type_Conversion then
Lhs := Expression (Lhs);
Rhs := Convert_To (Etype (Lhs), Rhs);
end if;
Rewrite (N,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Rhs));
Set_Assignment_OK (Lhs);
Analyze (N);
return;
-- For elementary types, we call the I_xxx routine using the first
-- parameter and then assign the result into the second parameter.
-- We set Assignment_OK to deal with the conversion case.
elsif Is_Elementary_Type (U_Type) then
declare
Lhs : Node_Id;
Rhs : Node_Id;
begin
Lhs := Relocate_Node (Next (First (Exprs)));
Rhs := Build_Elementary_Input_Call (N);
if Nkind (Lhs) = N_Type_Conversion then
Lhs := Expression (Lhs);
Rhs := Convert_To (Etype (Lhs), Rhs);
end if;
Set_Assignment_OK (Lhs);
Rewrite (N,
Make_Assignment_Statement (Loc,
Name => Lhs,
Expression => Rhs));
Analyze (N);
return;
end;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Read_Procedure (N, U_Type, Decl, Pname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Tagged type case, use the primitive Read function. Note that
-- this will dispatch in the class-wide case which is what we want
elsif Is_Tagged_Type (U_Type) then
Pname := Find_Prim_Op (U_Type, TSS_Stream_Read);
-- All other record type cases, including protected records.
-- The latter only arise for expander generated code for
-- handling shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
if Has_Discriminants (U_Type)
and then Present
(Discriminant_Default_Value (First_Discriminant (U_Type)))
then
Build_Mutable_Record_Read_Procedure
(Loc, Base_Type (U_Type), Decl, Pname);
else
Build_Record_Read_Procedure
(Loc, Base_Type (U_Type), Decl, Pname);
end if;
-- Suppress checks, uninitialized or otherwise invalid
-- data does not cause constraint errors to be raised for
-- a complete record read.
Insert_Action (N, Decl, All_Checks);
end if;
end if;
Rewrite_Stream_Proc_Call (Pname);
end Read;
---------------
-- Remainder --
---------------
-- Transforms 'Remainder into a call to the floating-point attribute
-- function Remainder in Fat_xxx (where xxx is the root type)
when Attribute_Remainder =>
Expand_Fpt_Attribute_RR (N);
-----------
-- Round --
-----------
-- The handling of the Round attribute is quite delicate. The
-- processing in Sem_Attr introduced a conversion to universal
-- real, reflecting the semantics of Round, but we do not want
-- anything to do with universal real at runtime, since this
-- corresponds to using floating-point arithmetic.
-- What we have now is that the Etype of the Round attribute
-- correctly indicates the final result type. The operand of
-- the Round is the conversion to universal real, described
-- above, and the operand of this conversion is the actual
-- operand of Round, which may be the special case of a fixed
-- point multiplication or division (Etype = universal fixed)
-- The exapander will expand first the operand of the conversion,
-- then the conversion, and finally the round attribute itself,
-- since we always work inside out. But we cannot simply process
-- naively in this order. In the semantic world where universal
-- fixed and real really exist and have infinite precision, there
-- is no problem, but in the implementation world, where universal
-- real is a floating-point type, we would get the wrong result.
-- So the approach is as follows. First, when expanding a multiply
-- or divide whose type is universal fixed, we do nothing at all,
-- instead deferring the operation till later.
-- The actual processing is done in Expand_N_Type_Conversion which
-- handles the special case of Round by looking at its parent to
-- see if it is a Round attribute, and if it is, handling the
-- conversion (or its fixed multiply/divide child) in an appropriate
-- manner.
-- This means that by the time we get to expanding the Round attribute
-- itself, the Round is nothing more than a type conversion (and will
-- often be a null type conversion), so we just replace it with the
-- appropriate conversion operation.
when Attribute_Round =>
Rewrite (N,
Convert_To (Etype (N), Relocate_Node (First (Exprs))));
Analyze_And_Resolve (N);
--------------
-- Rounding --
--------------
-- Transforms 'Rounding into a call to the floating-point attribute
-- function Rounding in Fat_xxx (where xxx is the root type)
when Attribute_Rounding =>
Expand_Fpt_Attribute_R (N);
-------------
-- Scaling --
-------------
-- Transforms 'Scaling into a call to the floating-point attribute
-- function Scaling in Fat_xxx (where xxx is the root type)
when Attribute_Scaling =>
Expand_Fpt_Attribute_RI (N);
----------
-- Size --
----------
when Attribute_Size |
Attribute_Object_Size |
Attribute_Value_Size |
Attribute_VADS_Size => Size :
declare
Ptyp : constant Entity_Id := Etype (Pref);
Siz : Uint;
New_Node : Node_Id;
begin
-- Processing for VADS_Size case. Note that this processing removes
-- all traces of VADS_Size from the tree, and completes all required
-- processing for VADS_Size by translating the attribute reference
-- to an appropriate Size or Object_Size reference.
if Id = Attribute_VADS_Size
or else (Use_VADS_Size and then Id = Attribute_Size)
then
-- If the size is specified, then we simply use the specified
-- size. This applies to both types and objects. The size of an
-- object can be specified in the following ways:
-- An explicit size object is given for an object
-- A component size is specified for an indexed component
-- A component clause is specified for a selected component
-- The object is a component of a packed composite object
-- If the size is specified, then VADS_Size of an object
if (Is_Entity_Name (Pref)
and then Present (Size_Clause (Entity (Pref))))
or else
(Nkind (Pref) = N_Component_Clause
and then (Present (Component_Clause
(Entity (Selector_Name (Pref))))
or else Is_Packed (Etype (Prefix (Pref)))))
or else
(Nkind (Pref) = N_Indexed_Component
and then (Component_Size (Etype (Prefix (Pref))) /= 0
or else Is_Packed (Etype (Prefix (Pref)))))
then
Set_Attribute_Name (N, Name_Size);
-- Otherwise if we have an object rather than a type, then the
-- VADS_Size attribute applies to the type of the object, rather
-- than the object itself. This is one of the respects in which
-- VADS_Size differs from Size.
else
if (not Is_Entity_Name (Pref)
or else not Is_Type (Entity (Pref)))
and then (Is_Scalar_Type (Etype (Pref))
or else Is_Constrained (Etype (Pref)))
then
Rewrite (Pref, New_Occurrence_Of (Etype (Pref), Loc));
end if;
-- For a scalar type for which no size was
-- explicitly given, VADS_Size means Object_Size. This is the
-- other respect in which VADS_Size differs from Size.
if Is_Scalar_Type (Etype (Pref))
and then No (Size_Clause (Etype (Pref)))
then
Set_Attribute_Name (N, Name_Object_Size);
-- In all other cases, Size and VADS_Size are the sane
else
Set_Attribute_Name (N, Name_Size);
end if;
end if;
end if;
-- For class-wide types, X'Class'Size is transformed into a
-- direct reference to the Size of the class type, so that gigi
-- does not have to deal with the X'Class'Size 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'Size applied to an object of a class wide type, transform
-- X'Size into a call to the primitive operation _Size applied to X.
elsif Is_Class_Wide_Type (Ptyp) then
New_Node :=
Make_Function_Call (Loc,
Name => New_Reference_To
(Find_Prim_Op (Ptyp, Name_uSize), Loc),
Parameter_Associations => New_List (Pref));
if Typ /= Standard_Long_Long_Integer then
-- The context is a specific integer type with which the
-- original attribute was compatible. The function has a
-- specific type as well, so to preserve the compatibility
-- we must convert explicitly.
New_Node := Convert_To (Typ, New_Node);
end if;
Rewrite (N, New_Node);
Analyze_And_Resolve (N, Typ);
return;
-- For an array component, we can do Size in the front end
-- if the component_size of the array is set.
elsif Nkind (Pref) = N_Indexed_Component then
Siz := Component_Size (Etype (Prefix (Pref)));
-- For a record component, we can do Size in the front end
-- if there is a component clause, or if the record is packed
-- and the component's size is known at compile time.
elsif Nkind (Pref) = N_Selected_Component then
declare
Rec : constant Entity_Id := Etype (Prefix (Pref));
Comp : constant Entity_Id := Entity (Selector_Name (Pref));
begin
if Present (Component_Clause (Comp)) then
Siz := Esize (Comp);
elsif Is_Packed (Rec) then
Siz := RM_Size (Ptyp);
else
Apply_Universal_Integer_Attribute_Checks (N);
return;
end if;
end;
-- All other cases are handled by Gigi
else
Apply_Universal_Integer_Attribute_Checks (N);
-- If we have Size applied to a formal parameter, that is a
-- packed array subtype, then apply size to the actual subtype.
if Is_Entity_Name (Pref)
and then Is_Formal (Entity (Pref))
and then Is_Array_Type (Etype (Pref))
and then Is_Packed (Etype (Pref))
then
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Get_Actual_Subtype (Pref), Loc),
Attribute_Name => Name_Size));
Analyze_And_Resolve (N, Typ);
end if;
return;
end if;
-- Common processing for record and array component case
if Siz /= 0 then
Rewrite (N,
Make_Integer_Literal (Loc, Siz));
Analyze_And_Resolve (N, Typ);
-- The result is not a static expression
Set_Is_Static_Expression (N, False);
end if;
end Size;
------------------
-- Storage_Pool --
------------------
when Attribute_Storage_Pool =>
Rewrite (N,
Make_Type_Conversion (Loc,
Subtype_Mark => New_Reference_To (Etype (N), Loc),
Expression => New_Reference_To (Entity (N), Loc)));
Analyze_And_Resolve (N, Typ);
------------------
-- Storage_Size --
------------------
when Attribute_Storage_Size => Storage_Size :
declare
Ptyp : constant Entity_Id := Etype (Pref);
begin
-- Access type case, always go to the root type
-- The case of access types results in a value of zero for the case
-- where no storage size attribute clause has been given. If a
-- storage size has been given, then the attribute is converted
-- to a reference to the variable used to hold this value.
if Is_Access_Type (Ptyp) then
if Present (Storage_Size_Variable (Root_Type (Ptyp))) then
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Typ, Loc),
Attribute_Name => Name_Max,
Expressions => New_List (
Make_Integer_Literal (Loc, 0),
Convert_To (Typ,
New_Reference_To
(Storage_Size_Variable (Root_Type (Ptyp)), Loc)))));
elsif Present (Associated_Storage_Pool (Root_Type (Ptyp))) then
Rewrite (N,
OK_Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Reference_To
(Find_Prim_Op
(Etype (Associated_Storage_Pool (Root_Type (Ptyp))),
Attribute_Name (N)),
Loc),
Parameter_Associations => New_List (New_Reference_To (
Associated_Storage_Pool (Root_Type (Ptyp)), Loc)))));
else
Rewrite (N, Make_Integer_Literal (Loc, 0));
end if;
Analyze_And_Resolve (N, Typ);
-- The case of a task type (an obsolescent feature) is handled the
-- same way, seems as reasonable as anything, and it is what the
-- ACVC tests (e.g. CD1009K) seem to expect.
-- If there is no Storage_Size variable, then we return the default
-- task stack size, otherwise, expand a Storage_Size attribute as
-- follows:
-- Typ (Adjust_Storage_Size (taskZ))
-- except for the case of a task object which has a Storage_Size
-- pragma:
-- Typ (Adjust_Storage_Size (taskV!(name)._Size))
else
if not Present (Storage_Size_Variable (Ptyp)) then
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name =>
New_Occurrence_Of (RTE (RE_Default_Stack_Size), Loc))));
else
if not (Is_Entity_Name (Pref) and then
Is_Task_Type (Entity (Pref))) and then
Chars (Last_Entity (Corresponding_Record_Type (Ptyp))) =
Name_uSize
then
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (
RTE (RE_Adjust_Storage_Size), Loc),
Parameter_Associations =>
New_List (
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (
Corresponding_Record_Type (Ptyp),
New_Copy_Tree (Pref)),
Selector_Name =>
Make_Identifier (Loc, Name_uSize))))));
-- Task not having Storage_Size pragma
else
Rewrite (N,
Convert_To (Typ,
Make_Function_Call (Loc,
Name => New_Occurrence_Of (
RTE (RE_Adjust_Storage_Size), Loc),
Parameter_Associations =>
New_List (
New_Reference_To (
Storage_Size_Variable (Ptyp), Loc)))));
end if;
Analyze_And_Resolve (N, Typ);
end if;
end if;
end Storage_Size;
----------
-- Succ --
----------
-- 1. Deal with enumeration types with holes
-- 2. For floating-point, generate call to attribute function
-- 3. For other cases, deal with constraint checking
when Attribute_Succ => Succ :
declare
Ptyp : constant Entity_Id := Base_Type (Etype (Pref));
begin
-- For enumeration types with non-standard representations, we
-- expand typ'Succ (x) into
-- Pos_To_Rep (Rep_To_Pos (x) + 1)
-- If the representation is contiguous, we compute instead
-- Lit1 + Rep_to_Pos (x+1), to catch invalid representations.
if Is_Enumeration_Type (Ptyp)
and then Present (Enum_Pos_To_Rep (Ptyp))
then
if Has_Contiguous_Rep (Ptyp) then
Rewrite (N,
Unchecked_Convert_To (Ptyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Ptyp))),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Ptyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations =>
New_List (
Unchecked_Convert_To (Ptyp,
Make_Op_Add (Loc,
Left_Opnd =>
Unchecked_Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))),
Right_Opnd =>
Make_Integer_Literal (Loc, 1))),
Rep_To_Pos_Flag (Ptyp, Loc))))));
else
-- Add Boolean parameter True, to request program errror if
-- we have a bad representation on our hands. Add False if
-- checks are suppressed.
Append_To (Exprs, Rep_To_Pos_Flag (Ptyp, Loc));
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Enum_Pos_To_Rep (Ptyp), Loc),
Expressions => New_List (
Make_Op_Add (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Ptyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => Exprs),
Right_Opnd => Make_Integer_Literal (Loc, 1)))));
end if;
Analyze_And_Resolve (N, Typ);
-- For floating-point, we transform 'Succ into a call to the Succ
-- floating-point attribute function in Fat_xxx (xxx is root type)
elsif Is_Floating_Point_Type (Ptyp) then
Expand_Fpt_Attribute_R (N);
Analyze_And_Resolve (N, Typ);
-- For modular types, nothing to do (no overflow, since wraps)
elsif Is_Modular_Integer_Type (Ptyp) then
null;
-- For other types, if range checking is enabled, we must generate
-- a check if overflow checking is enabled.
elsif not Overflow_Checks_Suppressed (Ptyp) then
Expand_Pred_Succ (N);
end if;
end Succ;
---------
-- Tag --
---------
-- Transforms X'Tag into a direct reference to the tag of X
when Attribute_Tag => Tag :
declare
Ttyp : Entity_Id;
Prefix_Is_Type : Boolean;
begin
if Is_Entity_Name (Pref) and then Is_Type (Entity (Pref)) then
Ttyp := Entity (Pref);
Prefix_Is_Type := True;
else
Ttyp := Etype (Pref);
Prefix_Is_Type := False;
end if;
if Is_Class_Wide_Type (Ttyp) then
Ttyp := Root_Type (Ttyp);
end if;
Ttyp := Underlying_Type (Ttyp);
if Prefix_Is_Type then
-- For JGNAT we leave the type attribute unexpanded because
-- there's not a dispatching table to reference.
if not Java_VM then
Rewrite (N,
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To (Access_Disp_Table (Ttyp), Loc)));
Analyze_And_Resolve (N, RTE (RE_Tag));
end if;
else
Rewrite (N,
Make_Selected_Component (Loc,
Prefix => Relocate_Node (Pref),
Selector_Name =>
New_Reference_To (Tag_Component (Ttyp), Loc)));
Analyze_And_Resolve (N, RTE (RE_Tag));
end if;
end Tag;
----------------
-- Terminated --
----------------
-- Transforms 'Terminated attribute into a call to Terminated function.
when Attribute_Terminated => Terminated :
begin
if Restricted_Profile then
Rewrite (N,
Build_Call_With_Task (Pref, RTE (RE_Restricted_Terminated)));
else
Rewrite (N,
Build_Call_With_Task (Pref, RTE (RE_Terminated)));
end if;
Analyze_And_Resolve (N, Standard_Boolean);
end Terminated;
----------------
-- To_Address --
----------------
-- Transforms System'To_Address (X) into unchecked conversion
-- from (integral) type of X to type address.
when Attribute_To_Address =>
Rewrite (N,
Unchecked_Convert_To (RTE (RE_Address),
Relocate_Node (First (Exprs))));
Analyze_And_Resolve (N, RTE (RE_Address));
----------------
-- Truncation --
----------------
-- Transforms 'Truncation into a call to the floating-point attribute
-- function Truncation in Fat_xxx (where xxx is the root type)
when Attribute_Truncation =>
Expand_Fpt_Attribute_R (N);
-----------------------
-- Unbiased_Rounding --
-----------------------
-- Transforms 'Unbiased_Rounding into a call to the floating-point
-- attribute function Unbiased_Rounding in Fat_xxx (where xxx is the
-- root type)
when Attribute_Unbiased_Rounding =>
Expand_Fpt_Attribute_R (N);
----------------------
-- Unchecked_Access --
----------------------
when Attribute_Unchecked_Access =>
Expand_Access_To_Type (N);
-----------------
-- UET_Address --
-----------------
when Attribute_UET_Address => UET_Address : declare
Ent : constant Entity_Id :=
Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
begin
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Ent,
Aliased_Present => True,
Object_Definition =>
New_Occurrence_Of (RTE (RE_Address), Loc)));
-- Construct name __gnat_xxx__SDP, where xxx is the unit name
-- in normal external form.
Get_External_Unit_Name_String (Get_Unit_Name (Pref));
Name_Buffer (1 + 7 .. Name_Len + 7) := Name_Buffer (1 .. Name_Len);
Name_Len := Name_Len + 7;
Name_Buffer (1 .. 7) := "__gnat_";
Name_Buffer (Name_Len + 1 .. Name_Len + 5) := "__SDP";
Name_Len := Name_Len + 5;
Set_Is_Imported (Ent);
Set_Interface_Name (Ent,
Make_String_Literal (Loc,
Strval => String_From_Name_Buffer));
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ent, Loc),
Attribute_Name => Name_Address));
Analyze_And_Resolve (N, Typ);
end UET_Address;
-------------------------
-- Unrestricted_Access --
-------------------------
when Attribute_Unrestricted_Access =>
Expand_Access_To_Type (N);
---------------
-- VADS_Size --
---------------
-- The processing for VADS_Size is shared with Size
---------
-- Val --
---------
-- For enumeration types with a standard representation, and for all
-- other types, Val is handled by Gigi. For enumeration types with
-- a non-standard representation we use the _Pos_To_Rep array that
-- was created when the type was frozen.
when Attribute_Val => Val :
declare
Etyp : constant Entity_Id := Base_Type (Entity (Pref));
begin
if Is_Enumeration_Type (Etyp)
and then Present (Enum_Pos_To_Rep (Etyp))
then
if Has_Contiguous_Rep (Etyp) then
declare
Rep_Node : constant Node_Id :=
Unchecked_Convert_To (Etyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Etyp))),
Right_Opnd =>
(Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))))));
begin
Rewrite (N,
Unchecked_Convert_To (Etyp,
Make_Op_Add (Loc,
Left_Opnd =>
Make_Integer_Literal (Loc,
Enumeration_Rep (First_Literal (Etyp))),
Right_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Etyp, TSS_Rep_To_Pos), Loc),
Parameter_Associations => New_List (
Rep_Node,
Rep_To_Pos_Flag (Etyp, Loc))))));
end;
else
Rewrite (N,
Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Enum_Pos_To_Rep (Etyp), Loc),
Expressions => New_List (
Convert_To (Standard_Integer,
Relocate_Node (First (Exprs))))));
end if;
Analyze_And_Resolve (N, Typ);
end if;
end Val;
-----------
-- Valid --
-----------
-- The code for valid is dependent on the particular types involved.
-- See separate sections below for the generated code in each case.
when Attribute_Valid => Valid :
declare
Ptyp : constant Entity_Id := Etype (Pref);
Btyp : Entity_Id := Base_Type (Ptyp);
Tst : Node_Id;
Save_Validity_Checks_On : constant Boolean := Validity_Checks_On;
-- Save the validity checking mode. We always turn off validity
-- checking during process of 'Valid since this is one place
-- where we do not want the implicit validity checks to intefere
-- with the explicit validity check that the programmer is doing.
function Make_Range_Test return Node_Id;
-- Build the code for a range test of the form
-- Btyp!(Pref) >= Btyp!(Ptyp'First)
-- and then
-- Btyp!(Pref) <= Btyp!(Ptyp'Last)
---------------------
-- Make_Range_Test --
---------------------
function Make_Range_Test return Node_Id is
begin
return
Make_And_Then (Loc,
Left_Opnd =>
Make_Op_Ge (Loc,
Left_Opnd =>
Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
Right_Opnd =>
Unchecked_Convert_To (Btyp,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_First))),
Right_Opnd =>
Make_Op_Le (Loc,
Left_Opnd =>
Unchecked_Convert_To (Btyp,
Duplicate_Subexpr_No_Checks (Pref)),
Right_Opnd =>
Unchecked_Convert_To (Btyp,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_Last))));
end Make_Range_Test;
-- Start of processing for Attribute_Valid
begin
-- Turn off validity checks. We do not want any implicit validity
-- checks to intefere with the explicit check from the attribute
Validity_Checks_On := False;
-- Floating-point case. This case is handled by the Valid attribute
-- code in the floating-point attribute run-time library.
if Is_Floating_Point_Type (Ptyp) then
declare
Rtp : constant Entity_Id := Root_Type (Etype (Pref));
begin
-- If the floating-point object might be unaligned, we need
-- to call the special routine Unaligned_Valid, which makes
-- the needed copy, being careful not to load the value into
-- any floating-point register. The argument in this case is
-- obj'Address (see Unchecked_Valid routine in s-fatgen.ads).
if Is_Possibly_Unaligned_Object (Pref) then
Set_Attribute_Name (N, Name_Unaligned_Valid);
Expand_Fpt_Attribute
(N, Rtp, Name_Unaligned_Valid,
New_List (
Make_Attribute_Reference (Loc,
Prefix => Relocate_Node (Pref),
Attribute_Name => Name_Address)));
-- In the normal case where we are sure the object is aligned,
-- we generate a caqll to Valid, and the argument in this case
-- is obj'Unrestricted_Access (after converting obj to the
-- right floating-point type).
else
Expand_Fpt_Attribute
(N, Rtp, Name_Valid,
New_List (
Make_Attribute_Reference (Loc,
Prefix => Unchecked_Convert_To (Rtp, Pref),
Attribute_Name => Name_Unrestricted_Access)));
end if;
-- One more task, we still need a range check. Required
-- only if we have a constraint, since the Valid routine
-- catches infinities properly (infinities are never valid).
-- The way we do the range check is simply to create the
-- expression: Valid (N) and then Base_Type(Pref) in Typ.
if not Subtypes_Statically_Match (Ptyp, Btyp) then
Rewrite (N,
Make_And_Then (Loc,
Left_Opnd => Relocate_Node (N),
Right_Opnd =>
Make_In (Loc,
Left_Opnd => Convert_To (Btyp, Pref),
Right_Opnd => New_Occurrence_Of (Ptyp, Loc))));
end if;
end;
-- Enumeration type with holes
-- For enumeration types with holes, the Pos value constructed by
-- the Enum_Rep_To_Pos function built in Exp_Ch3 called with a
-- second argument of False returns minus one for an invalid value,
-- and the non-negative pos value for a valid value, so the
-- expansion of X'Valid is simply:
-- type(X)'Pos (X) >= 0
-- We can't quite generate it that way because of the requirement
-- for the non-standard second argument of False, so we have to
-- explicitly create:
-- _rep_to_pos (X, False) >= 0
-- If we have an enumeration subtype, we also check that the
-- value is in range:
-- _rep_to_pos (X, False) >= 0
-- and then
-- (X >= type(X)'First and then type(X)'Last <= X)
elsif Is_Enumeration_Type (Ptyp)
and then Present (Enum_Pos_To_Rep (Base_Type (Ptyp)))
then
Tst :=
Make_Op_Ge (Loc,
Left_Opnd =>
Make_Function_Call (Loc,
Name =>
New_Reference_To
(TSS (Base_Type (Ptyp), TSS_Rep_To_Pos), Loc),
Parameter_Associations => New_List (
Pref,
New_Occurrence_Of (Standard_False, Loc))),
Right_Opnd => Make_Integer_Literal (Loc, 0));
if Ptyp /= Btyp
and then
(Type_Low_Bound (Ptyp) /= Type_Low_Bound (Btyp)
or else
Type_High_Bound (Ptyp) /= Type_High_Bound (Btyp))
then
-- The call to Make_Range_Test will create declarations
-- that need a proper insertion point, but Pref is now
-- attached to a node with no ancestor. Attach to tree
-- even if it is to be rewritten below.
Set_Parent (Tst, Parent (N));
Tst :=
Make_And_Then (Loc,
Left_Opnd => Make_Range_Test,
Right_Opnd => Tst);
end if;
Rewrite (N, Tst);
-- Fortran convention booleans
-- For the very special case of Fortran convention booleans, the
-- value is always valid, since it is an integer with the semantics
-- that non-zero is true, and any value is permissible.
elsif Is_Boolean_Type (Ptyp)
and then Convention (Ptyp) = Convention_Fortran
then
Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
-- For biased representations, we will be doing an unchecked
-- conversion without unbiasing the result. That means that
-- the range test has to take this into account, and the
-- proper form of the test is:
-- Btyp!(Pref) < Btyp!(Ptyp'Range_Length)
elsif Has_Biased_Representation (Ptyp) then
Btyp := RTE (RE_Unsigned_32);
Rewrite (N,
Make_Op_Lt (Loc,
Left_Opnd =>
Unchecked_Convert_To (Btyp, Duplicate_Subexpr (Pref)),
Right_Opnd =>
Unchecked_Convert_To (Btyp,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Ptyp, Loc),
Attribute_Name => Name_Range_Length))));
-- For all other scalar types, what we want logically is a
-- range test:
-- X in type(X)'First .. type(X)'Last
-- But that's precisely what won't work because of possible
-- unwanted optimization (and indeed the basic motivation for
-- the Valid attribute -is exactly that this test does not work.
-- What will work is:
-- Btyp!(X) >= Btyp!(type(X)'First)
-- and then
-- Btyp!(X) <= Btyp!(type(X)'Last)
-- where Btyp is an integer type large enough to cover the full
-- range of possible stored values (i.e. it is chosen on the basis
-- of the size of the type, not the range of the values). We write
-- this as two tests, rather than a range check, so that static
-- evaluation will easily remove either or both of the checks if
-- they can be -statically determined to be true (this happens
-- when the type of X is static and the range extends to the full
-- range of stored values).
-- Unsigned types. Note: it is safe to consider only whether the
-- subtype is unsigned, since we will in that case be doing all
-- unsigned comparisons based on the subtype range. Since we use
-- the actual subtype object size, this is appropriate.
-- For example, if we have
-- subtype x is integer range 1 .. 200;
-- for x'Object_Size use 8;
-- Now the base type is signed, but objects of this type are 8
-- bits unsigned, and doing an unsigned test of the range 1 to
-- 200 is correct, even though a value greater than 127 looks
-- signed to a signed comparison.
elsif Is_Unsigned_Type (Ptyp) then
if Esize (Ptyp) <= 32 then
Btyp := RTE (RE_Unsigned_32);
else
Btyp := RTE (RE_Unsigned_64);
end if;
Rewrite (N, Make_Range_Test);
-- Signed types
else
if Esize (Ptyp) <= Esize (Standard_Integer) then
Btyp := Standard_Integer;
else
Btyp := Universal_Integer;
end if;
Rewrite (N, Make_Range_Test);
end if;
Analyze_And_Resolve (N, Standard_Boolean);
Validity_Checks_On := Save_Validity_Checks_On;
end Valid;
-----------
-- Value --
-----------
-- Value attribute is handled in separate unti Exp_Imgv
when Attribute_Value =>
Exp_Imgv.Expand_Value_Attribute (N);
-----------------
-- Value_Size --
-----------------
-- The processing for Value_Size shares the processing for Size
-------------
-- Version --
-------------
-- The processing for Version shares the processing for Body_Version
----------------
-- Wide_Image --
----------------
-- We expand typ'Wide_Image (X) into
-- String_To_Wide_String
-- (typ'Image (X), Wide_Character_Encoding_Method)
-- This works in all cases because String_To_Wide_String converts any
-- wide character escape sequences resulting from the Image call to the
-- proper Wide_Character equivalent
-- not quite right for typ = Wide_Character ???
when Attribute_Wide_Image => Wide_Image :
begin
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_String_To_Wide_String), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => Pref,
Attribute_Name => Name_Image,
Expressions => Exprs),
Make_Integer_Literal (Loc,
Intval => Int (Wide_Character_Encoding_Method)))));
Analyze_And_Resolve (N, Standard_Wide_String);
end Wide_Image;
----------------
-- Wide_Value --
----------------
-- We expand typ'Wide_Value (X) into
-- typ'Value
-- (Wide_String_To_String (X, Wide_Character_Encoding_Method))
-- Wide_String_To_String is a runtime function that converts its wide
-- string argument to String, converting any non-translatable characters
-- into appropriate escape sequences. This preserves the required
-- semantics of Wide_Value in all cases, and results in a very simple
-- implementation approach.
-- It's not quite right where typ = Wide_Character, because the encoding
-- method may not cover the whole character type ???
when Attribute_Wide_Value => Wide_Value :
begin
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => Pref,
Attribute_Name => Name_Value,
Expressions => New_List (
Make_Function_Call (Loc,
Name =>
New_Reference_To (RTE (RE_Wide_String_To_String), Loc),
Parameter_Associations => New_List (
Relocate_Node (First (Exprs)),
Make_Integer_Literal (Loc,
Intval => Int (Wide_Character_Encoding_Method)))))));
Analyze_And_Resolve (N, Typ);
end Wide_Value;
----------------
-- Wide_Width --
----------------
-- Wide_Width attribute is handled in separate unit Exp_Imgv
when Attribute_Wide_Width =>
Exp_Imgv.Expand_Width_Attribute (N, Wide => True);
-----------
-- Width --
-----------
-- Width attribute is handled in separate unit Exp_Imgv
when Attribute_Width =>
Exp_Imgv.Expand_Width_Attribute (N, Wide => False);
-----------
-- Write --
-----------
when Attribute_Write => Write : declare
P_Type : constant Entity_Id := Entity (Pref);
U_Type : constant Entity_Id := Underlying_Type (P_Type);
Pname : Entity_Id;
Decl : Node_Id;
Prag : Node_Id;
Arg3 : Node_Id;
Wfunc : Node_Id;
begin
-- If no underlying type, we have an error that will be diagnosed
-- elsewhere, so here we just completely ignore the expansion.
if No (U_Type) then
return;
end if;
-- The simple case, if there is a TSS for Write, just call it
Pname := Find_Stream_Subprogram (P_Type, TSS_Stream_Write);
if Present (Pname) then
null;
else
-- If there is a Stream_Convert pragma, use it, we rewrite
-- sourcetyp'Output (stream, Item)
-- as
-- strmtyp'Output (Stream, strmwrite (acttyp (Item)));
-- where strmwrite is the given Write function that converts
-- an argument of type sourcetyp or a type acctyp, from which
-- it is derived to type strmtyp. The conversion to acttyp is
-- required for the derived case.
Prag :=
Get_Rep_Pragma
(Implementation_Base_Type (P_Type), Name_Stream_Convert);
if Present (Prag) then
Arg3 :=
Next (Next (First (Pragma_Argument_Associations (Prag))));
Wfunc := Entity (Expression (Arg3));
Rewrite (N,
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Etype (Wfunc), Loc),
Attribute_Name => Name_Output,
Expressions => New_List (
Relocate_Node (First (Exprs)),
Make_Function_Call (Loc,
Name => New_Occurrence_Of (Wfunc, Loc),
Parameter_Associations => New_List (
Convert_To (Etype (First_Formal (Wfunc)),
Relocate_Node (Next (First (Exprs)))))))));
Analyze (N);
return;
-- For elementary types, we call the W_xxx routine directly
elsif Is_Elementary_Type (U_Type) then
Rewrite (N, Build_Elementary_Write_Call (N));
Analyze (N);
return;
-- Array type case
elsif Is_Array_Type (U_Type) then
Build_Array_Write_Procedure (N, U_Type, Decl, Pname);
Compile_Stream_Body_In_Scope (N, Decl, U_Type, Check => False);
-- Tagged type case, use the primitive Write function. Note that
-- this will dispatch in the class-wide case which is what we want
elsif Is_Tagged_Type (U_Type) then
Pname := Find_Prim_Op (U_Type, TSS_Stream_Write);
-- All other record type cases, including protected records.
-- The latter only arise for expander generated code for
-- handling shared passive partition access.
else
pragma Assert
(Is_Record_Type (U_Type) or else Is_Protected_Type (U_Type));
if Has_Discriminants (U_Type)
and then Present
(Discriminant_Default_Value (First_Discriminant (U_Type)))
then
Build_Mutable_Record_Write_Procedure
(Loc, Base_Type (U_Type), Decl, Pname);
else
Build_Record_Write_Procedure
(Loc, Base_Type (U_Type), Decl, Pname);
end if;
Insert_Action (N, Decl);
end if;
end if;
-- If we fall through, Pname is the procedure to be called
Rewrite_Stream_Proc_Call (Pname);
end Write;
-- Component_Size is handled by Gigi, unless the component size is
-- known at compile time, which is always true in the packed array
-- case. It is important that the packed array case is handled in
-- the front end (see Eval_Attribute) since Gigi would otherwise
-- get confused by the equivalent packed array type.
when Attribute_Component_Size =>
null;
-- The following attributes are handled by Gigi (except that static
-- cases have already been evaluated by the semantics, but in any
-- case Gigi should not count on that).
-- In addition Gigi handles the non-floating-point cases of Pred
-- and Succ (including the fixed-point cases, which can just be
-- treated as integer increment/decrement operations)
-- Gigi also handles the non-class-wide cases of Size
when Attribute_Bit_Order |
Attribute_Code_Address |
Attribute_Definite |
Attribute_Max |
Attribute_Mechanism_Code |
Attribute_Min |
Attribute_Null_Parameter |
Attribute_Passed_By_Reference |
Attribute_Pool_Address =>
null;
-- The following attributes are also handled by Gigi, but return a
-- universal integer result, so may need a conversion for checking
-- that the result is in range.
when Attribute_Aft |
Attribute_Bit |
Attribute_Max_Size_In_Storage_Elements
=>
Apply_Universal_Integer_Attribute_Checks (N);
-- The following attributes should not appear at this stage, since they
-- have already been handled by the analyzer (and properly rewritten
-- with corresponding values or entities to represent the right values)
when Attribute_Abort_Signal |
Attribute_Address_Size |
Attribute_Base |
Attribute_Class |
Attribute_Default_Bit_Order |
Attribute_Delta |
Attribute_Denorm |
Attribute_Digits |
Attribute_Emax |
Attribute_Epsilon |
Attribute_Has_Discriminants |
Attribute_Large |
Attribute_Machine_Emax |
Attribute_Machine_Emin |
Attribute_Machine_Mantissa |
Attribute_Machine_Overflows |
Attribute_Machine_Radix |
Attribute_Machine_Rounds |
Attribute_Maximum_Alignment |
Attribute_Model_Emin |
Attribute_Model_Epsilon |
Attribute_Model_Mantissa |
Attribute_Model_Small |
Attribute_Modulus |
Attribute_Partition_ID |
Attribute_Range |
Attribute_Safe_Emax |
Attribute_Safe_First |
Attribute_Safe_Large |
Attribute_Safe_Last |
Attribute_Safe_Small |
Attribute_Scale |
Attribute_Signed_Zeros |
Attribute_Small |
Attribute_Storage_Unit |
Attribute_Target_Name |
Attribute_Type_Class |
Attribute_Unconstrained_Array |
Attribute_Universal_Literal_String |
Attribute_Wchar_T_Size |
Attribute_Word_Size =>
raise Program_Error;
-- 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 Gigi will never see these either.
when Attribute_Asm_Input |
Attribute_Asm_Output =>
null;
end case;
exception
when RE_Not_Available =>
return;
end Expand_N_Attribute_Reference;
----------------------
-- Expand_Pred_Succ --
----------------------
-- For typ'Pred (exp), we generate the check
-- [constraint_error when exp = typ'Base'First]
-- Similarly, for typ'Succ (exp), we generate the check
-- [constraint_error when exp = typ'Base'Last]
-- These checks are not generated for modular types, since the proper
-- semantics for Succ and Pred on modular types is to wrap, not raise CE.
procedure Expand_Pred_Succ (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Cnam : Name_Id;
begin
if Attribute_Name (N) = Name_Pred then
Cnam := Name_First;
else
Cnam := Name_Last;
end if;
Insert_Action (N,
Make_Raise_Constraint_Error (Loc,
Condition =>
Make_Op_Eq (Loc,
Left_Opnd =>
Duplicate_Subexpr_Move_Checks (First (Expressions (N))),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix =>
New_Reference_To (Base_Type (Etype (Prefix (N))), Loc),
Attribute_Name => Cnam)),
Reason => CE_Overflow_Check_Failed));
end Expand_Pred_Succ;
------------------------
-- Find_Inherited_TSS --
------------------------
function Find_Inherited_TSS
(Typ : Entity_Id;
Nam : TSS_Name_Type) return Entity_Id
is
Btyp : Entity_Id := Typ;
Proc : Entity_Id;
begin
loop
Btyp := Base_Type (Btyp);
Proc := TSS (Btyp, Nam);
exit when Present (Proc)
or else not Is_Derived_Type (Btyp);
-- If Typ is a derived type, it may inherit attributes from
-- some ancestor.
Btyp := Etype (Btyp);
end loop;
if No (Proc) then
-- If nothing else, use the TSS of the root type
Proc := TSS (Base_Type (Underlying_Type (Typ)), Nam);
end if;
return Proc;
end Find_Inherited_TSS;
----------------------------
-- Find_Stream_Subprogram --
----------------------------
function Find_Stream_Subprogram
(Typ : Entity_Id;
Nam : TSS_Name_Type) return Entity_Id is
begin
if Is_Tagged_Type (Typ)
and then Is_Derived_Type (Typ)
then
return Find_Prim_Op (Typ, Nam);
else
return Find_Inherited_TSS (Typ, Nam);
end if;
end Find_Stream_Subprogram;
-----------------------
-- Get_Index_Subtype --
-----------------------
function Get_Index_Subtype (N : Node_Id) return Node_Id is
P_Type : Entity_Id := Etype (Prefix (N));
Indx : Node_Id;
J : Int;
begin
if Is_Access_Type (P_Type) then
P_Type := Designated_Type (P_Type);
end if;
if No (Expressions (N)) then
J := 1;
else
J := UI_To_Int (Expr_Value (First (Expressions (N))));
end if;
Indx := First_Index (P_Type);
while J > 1 loop
Next_Index (Indx);
J := J - 1;
end loop;
return Etype (Indx);
end Get_Index_Subtype;
---------------------------------
-- Is_Constrained_Packed_Array --
---------------------------------
function Is_Constrained_Packed_Array (Typ : Entity_Id) return Boolean is
Arr : Entity_Id := Typ;
begin
if Is_Access_Type (Arr) then
Arr := Designated_Type (Arr);
end if;
return Is_Array_Type (Arr)
and then Is_Constrained (Arr)
and then Present (Packed_Array_Type (Arr));
end Is_Constrained_Packed_Array;
end Exp_Attr;