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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- F R E E Z E --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2004, 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 Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch11; use Exp_Ch11;
with Exp_Pakd; use Exp_Pakd;
with Exp_Util; use Exp_Util;
with Exp_Tss; use Exp_Tss;
with Layout; use Layout;
with Lib.Xref; use Lib.Xref;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Sem; use Sem;
with Sem_Cat; use Sem_Cat;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Prag; use Sem_Prag;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Urealp; use Urealp;
package body Freeze is
-----------------------
-- Local Subprograms --
-----------------------
procedure Adjust_Esize_For_Alignment (Typ : Entity_Id);
-- Typ is a type that is being frozen. If no size clause is given,
-- but a default Esize has been computed, then this default Esize is
-- adjusted up if necessary to be consistent with a given alignment,
-- but never to a value greater than Long_Long_Integer'Size. This
-- is used for all discrete types and for fixed-point types.
procedure Build_And_Analyze_Renamed_Body
(Decl : Node_Id;
New_S : Entity_Id;
After : in out Node_Id);
-- Build body for a renaming declaration, insert in tree and analyze.
procedure Check_Address_Clause (E : Entity_Id);
-- Apply legality checks to address clauses for object declarations,
-- at the point the object is frozen.
procedure Check_Strict_Alignment (E : Entity_Id);
-- E is a base type. If E is tagged or has a component that is aliased
-- or tagged or contains something this is aliased or tagged, set
-- Strict_Alignment.
procedure Check_Unsigned_Type (E : Entity_Id);
pragma Inline (Check_Unsigned_Type);
-- If E is a fixed-point or discrete type, then all the necessary work
-- to freeze it is completed except for possible setting of the flag
-- Is_Unsigned_Type, which is done by this procedure. The call has no
-- effect if the entity E is not a discrete or fixed-point type.
procedure Freeze_And_Append
(Ent : Entity_Id;
Loc : Source_Ptr;
Result : in out List_Id);
-- Freezes Ent using Freeze_Entity, and appends the resulting list of
-- nodes to Result, modifying Result from No_List if necessary.
procedure Freeze_Enumeration_Type (Typ : Entity_Id);
-- Freeze enumeration type. The Esize field is set as processing
-- proceeds (i.e. set by default when the type is declared and then
-- adjusted by rep clauses. What this procedure does is to make sure
-- that if a foreign convention is specified, and no specific size
-- is given, then the size must be at least Integer'Size.
procedure Freeze_Static_Object (E : Entity_Id);
-- If an object is frozen which has Is_Statically_Allocated set, then
-- all referenced types must also be marked with this flag. This routine
-- is in charge of meeting this requirement for the object entity E.
procedure Freeze_Subprogram (E : Entity_Id);
-- Perform freezing actions for a subprogram (create extra formals,
-- and set proper default mechanism values). Note that this routine
-- is not called for internal subprograms, for which neither of these
-- actions is needed (or desirable, we do not want for example to have
-- these extra formals present in initialization procedures, where they
-- would serve no purpose). In this call E is either a subprogram or
-- a subprogram type (i.e. an access to a subprogram).
function Is_Fully_Defined (T : Entity_Id) return Boolean;
-- True if T is not private and has no private components, or has a full
-- view. Used to determine whether the designated type of an access type
-- should be frozen when the access type is frozen. This is done when an
-- allocator is frozen, or an expression that may involve attributes of
-- the designated type. Otherwise freezing the access type does not freeze
-- the designated type.
procedure Process_Default_Expressions
(E : Entity_Id;
After : in out Node_Id);
-- This procedure is called for each subprogram to complete processing
-- of default expressions at the point where all types are known to be
-- frozen. The expressions must be analyzed in full, to make sure that
-- all error processing is done (they have only been pre-analyzed). If
-- the expression is not an entity or literal, its analysis may generate
-- code which must not be executed. In that case we build a function
-- body to hold that code. This wrapper function serves no other purpose
-- (it used to be called to evaluate the default, but now the default is
-- inlined at each point of call).
procedure Set_Component_Alignment_If_Not_Set (Typ : Entity_Id);
-- Typ is a record or array type that is being frozen. This routine
-- sets the default component alignment from the scope stack values
-- if the alignment is otherwise not specified.
procedure Check_Debug_Info_Needed (T : Entity_Id);
-- As each entity is frozen, this routine is called to deal with the
-- setting of Debug_Info_Needed for the entity. This flag is set if
-- the entity comes from source, or if we are in Debug_Generated_Code
-- mode or if the -gnatdV debug flag is set. However, it never sets
-- the flag if Debug_Info_Off is set.
procedure Set_Debug_Info_Needed (T : Entity_Id);
-- Sets the Debug_Info_Needed flag on entity T if not already set, and
-- also on any entities that are needed by T (for an object, the type
-- of the object is needed, and for a type, the subsidiary types are
-- needed -- see body for details). Never has any effect on T if the
-- Debug_Info_Off flag is set.
procedure Warn_Overlay
(Expr : Node_Id;
Typ : Entity_Id;
Nam : Node_Id);
-- Expr is the expression for an address clause for entity Nam whose type
-- is Typ. If Typ has a default initialization, and there is no explicit
-- initialization in the source declaration, check whether the address
-- clause might cause overlaying of an entity, and emit a warning on the
-- side effect that the initialization will cause.
-------------------------------
-- Adjust_Esize_For_Alignment --
-------------------------------
procedure Adjust_Esize_For_Alignment (Typ : Entity_Id) is
Align : Uint;
begin
if Known_Esize (Typ) and then Known_Alignment (Typ) then
Align := Alignment_In_Bits (Typ);
if Align > Esize (Typ)
and then Align <= Standard_Long_Long_Integer_Size
then
Set_Esize (Typ, Align);
end if;
end if;
end Adjust_Esize_For_Alignment;
------------------------------------
-- Build_And_Analyze_Renamed_Body --
------------------------------------
procedure Build_And_Analyze_Renamed_Body
(Decl : Node_Id;
New_S : Entity_Id;
After : in out Node_Id)
is
Body_Node : constant Node_Id := Build_Renamed_Body (Decl, New_S);
begin
Insert_After (After, Body_Node);
Mark_Rewrite_Insertion (Body_Node);
Analyze (Body_Node);
After := Body_Node;
end Build_And_Analyze_Renamed_Body;
------------------------
-- Build_Renamed_Body --
------------------------
function Build_Renamed_Body
(Decl : Node_Id;
New_S : Entity_Id) return Node_Id
is
Loc : constant Source_Ptr := Sloc (New_S);
-- We use for the source location of the renamed body, the location
-- of the spec entity. It might seem more natural to use the location
-- of the renaming declaration itself, but that would be wrong, since
-- then the body we create would look as though it was created far
-- too late, and this could cause problems with elaboration order
-- analysis, particularly in connection with instantiations.
N : constant Node_Id := Unit_Declaration_Node (New_S);
Nam : constant Node_Id := Name (N);
Old_S : Entity_Id;
Spec : constant Node_Id := New_Copy_Tree (Specification (Decl));
Actuals : List_Id := No_List;
Call_Node : Node_Id;
Call_Name : Node_Id;
Body_Node : Node_Id;
Formal : Entity_Id;
O_Formal : Entity_Id;
Param_Spec : Node_Id;
begin
-- Determine the entity being renamed, which is the target of the
-- call statement. If the name is an explicit dereference, this is
-- a renaming of a subprogram type rather than a subprogram. The
-- name itself is fully analyzed.
if Nkind (Nam) = N_Selected_Component then
Old_S := Entity (Selector_Name (Nam));
elsif Nkind (Nam) = N_Explicit_Dereference then
Old_S := Etype (Nam);
elsif Nkind (Nam) = N_Indexed_Component then
if Is_Entity_Name (Prefix (Nam)) then
Old_S := Entity (Prefix (Nam));
else
Old_S := Entity (Selector_Name (Prefix (Nam)));
end if;
elsif Nkind (Nam) = N_Character_Literal then
Old_S := Etype (New_S);
else
Old_S := Entity (Nam);
end if;
if Is_Entity_Name (Nam) then
-- If the renamed entity is a predefined operator, retain full
-- name to ensure its visibility.
if Ekind (Old_S) = E_Operator
and then Nkind (Nam) = N_Expanded_Name
then
Call_Name := New_Copy (Name (N));
else
Call_Name := New_Reference_To (Old_S, Loc);
end if;
else
Call_Name := New_Copy (Name (N));
-- The original name may have been overloaded, but
-- is fully resolved now.
Set_Is_Overloaded (Call_Name, False);
end if;
-- For simple renamings, subsequent calls can be expanded directly
-- as called to the renamed entity. The body must be generated in
-- any case for calls they may appear elsewhere.
if (Ekind (Old_S) = E_Function
or else Ekind (Old_S) = E_Procedure)
and then Nkind (Decl) = N_Subprogram_Declaration
then
Set_Body_To_Inline (Decl, Old_S);
end if;
-- The body generated for this renaming is an internal artifact, and
-- does not constitute a freeze point for the called entity.
Set_Must_Not_Freeze (Call_Name);
Formal := First_Formal (Defining_Entity (Decl));
if Present (Formal) then
Actuals := New_List;
while Present (Formal) loop
Append (New_Reference_To (Formal, Loc), Actuals);
Next_Formal (Formal);
end loop;
end if;
-- If the renamed entity is an entry, inherit its profile. For
-- other renamings as bodies, both profiles must be subtype
-- conformant, so it is not necessary to replace the profile given
-- in the declaration. However, default values that are aggregates
-- are rewritten when partially analyzed, so we recover the original
-- aggregate to insure that subsequent conformity checking works.
-- Similarly, if the default expression was constant-folded, recover
-- the original expression.
Formal := First_Formal (Defining_Entity (Decl));
if Present (Formal) then
O_Formal := First_Formal (Old_S);
Param_Spec := First (Parameter_Specifications (Spec));
while Present (Formal) loop
if Is_Entry (Old_S) then
if Nkind (Parameter_Type (Param_Spec)) /=
N_Access_Definition
then
Set_Etype (Formal, Etype (O_Formal));
Set_Entity (Parameter_Type (Param_Spec), Etype (O_Formal));
end if;
elsif Nkind (Default_Value (O_Formal)) = N_Aggregate
or else Nkind (Original_Node (Default_Value (O_Formal))) /=
Nkind (Default_Value (O_Formal))
then
Set_Expression (Param_Spec,
New_Copy_Tree (Original_Node (Default_Value (O_Formal))));
end if;
Next_Formal (Formal);
Next_Formal (O_Formal);
Next (Param_Spec);
end loop;
end if;
-- If the renamed entity is a function, the generated body contains a
-- return statement. Otherwise, build a procedure call. If the entity is
-- an entry, subsequent analysis of the call will transform it into the
-- proper entry or protected operation call. If the renamed entity is
-- a character literal, return it directly.
if Ekind (Old_S) = E_Function
or else Ekind (Old_S) = E_Operator
or else (Ekind (Old_S) = E_Subprogram_Type
and then Etype (Old_S) /= Standard_Void_Type)
then
Call_Node :=
Make_Return_Statement (Loc,
Expression =>
Make_Function_Call (Loc,
Name => Call_Name,
Parameter_Associations => Actuals));
elsif Ekind (Old_S) = E_Enumeration_Literal then
Call_Node :=
Make_Return_Statement (Loc,
Expression => New_Occurrence_Of (Old_S, Loc));
elsif Nkind (Nam) = N_Character_Literal then
Call_Node :=
Make_Return_Statement (Loc,
Expression => Call_Name);
else
Call_Node :=
Make_Procedure_Call_Statement (Loc,
Name => Call_Name,
Parameter_Associations => Actuals);
end if;
-- Create entities for subprogram body and formals.
Set_Defining_Unit_Name (Spec,
Make_Defining_Identifier (Loc, Chars => Chars (New_S)));
Param_Spec := First (Parameter_Specifications (Spec));
while Present (Param_Spec) loop
Set_Defining_Identifier (Param_Spec,
Make_Defining_Identifier (Loc,
Chars => Chars (Defining_Identifier (Param_Spec))));
Next (Param_Spec);
end loop;
Body_Node :=
Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Call_Node)));
if Nkind (Decl) /= N_Subprogram_Declaration then
Rewrite (N,
Make_Subprogram_Declaration (Loc,
Specification => Specification (N)));
end if;
-- Link the body to the entity whose declaration it completes. If
-- the body is analyzed when the renamed entity is frozen, it may be
-- necessary to restore the proper scope (see package Exp_Ch13).
if Nkind (N) = N_Subprogram_Renaming_Declaration
and then Present (Corresponding_Spec (N))
then
Set_Corresponding_Spec (Body_Node, Corresponding_Spec (N));
else
Set_Corresponding_Spec (Body_Node, New_S);
end if;
return Body_Node;
end Build_Renamed_Body;
--------------------------
-- Check_Address_Clause --
--------------------------
procedure Check_Address_Clause (E : Entity_Id) is
Addr : constant Node_Id := Address_Clause (E);
Expr : Node_Id;
Decl : constant Node_Id := Declaration_Node (E);
Typ : constant Entity_Id := Etype (E);
begin
if Present (Addr) then
Expr := Expression (Addr);
-- If we have no initialization of any kind, then we don't
-- need to place any restrictions on the address clause, because
-- the object will be elaborated after the address clause is
-- evaluated. This happens if the declaration has no initial
-- expression, or the type has no implicit initialization, or
-- the object is imported.
-- The same holds for all initialized scalar types and all
-- access types. Packed bit arrays of size up to 64 are
-- represented using a modular type with an initialization
-- (to zero) and can be processed like other initialized
-- scalar types.
-- If the type is controlled, code to attach the object to a
-- finalization chain is generated at the point of declaration,
-- and therefore the elaboration of the object cannot be delayed:
-- the address expression must be a constant.
if (No (Expression (Decl))
and then not Controlled_Type (Typ)
and then
(not Has_Non_Null_Base_Init_Proc (Typ)
or else Is_Imported (E)))
or else
(Present (Expression (Decl))
and then Is_Scalar_Type (Typ))
or else
Is_Access_Type (Typ)
or else
(Is_Bit_Packed_Array (Typ)
and then
Is_Modular_Integer_Type (Packed_Array_Type (Typ)))
then
null;
-- Otherwise, we require the address clause to be constant
-- because the call to the initialization procedure (or the
-- attach code) has to happen at the point of the declaration.
else
Check_Constant_Address_Clause (Expr, E);
Set_Has_Delayed_Freeze (E, False);
end if;
if not Error_Posted (Expr)
and then not Controlled_Type (Typ)
then
Warn_Overlay (Expr, Typ, Name (Addr));
end if;
end if;
end Check_Address_Clause;
-----------------------------
-- Check_Compile_Time_Size --
-----------------------------
procedure Check_Compile_Time_Size (T : Entity_Id) is
procedure Set_Small_Size (S : Uint);
-- Sets the compile time known size (32 bits or less) in the Esize
-- field, checking for a size clause that was given which attempts
-- to give a smaller size.
function Size_Known (T : Entity_Id) return Boolean;
-- Recursive function that does all the work
function Static_Discriminated_Components (T : Entity_Id) return Boolean;
-- If T is a constrained subtype, its size is not known if any of its
-- discriminant constraints is not static and it is not a null record.
-- The test is conservative and doesn't check that the components are
-- in fact constrained by non-static discriminant values. Could be made
-- more precise ???
--------------------
-- Set_Small_Size --
--------------------
procedure Set_Small_Size (S : Uint) is
begin
if S > 32 then
return;
elsif Has_Size_Clause (T) then
if RM_Size (T) < S then
Error_Msg_Uint_1 := S;
Error_Msg_NE
("size for & is too small, minimum is ^",
Size_Clause (T), T);
elsif Unknown_Esize (T) then
Set_Esize (T, S);
end if;
-- Set sizes if not set already
else
if Unknown_Esize (T) then
Set_Esize (T, S);
end if;
if Unknown_RM_Size (T) then
Set_RM_Size (T, S);
end if;
end if;
end Set_Small_Size;
----------------
-- Size_Known --
----------------
function Size_Known (T : Entity_Id) return Boolean is
Index : Entity_Id;
Comp : Entity_Id;
Ctyp : Entity_Id;
Low : Node_Id;
High : Node_Id;
begin
if Size_Known_At_Compile_Time (T) then
return True;
elsif Is_Scalar_Type (T)
or else Is_Task_Type (T)
then
return not Is_Generic_Type (T);
elsif Is_Array_Type (T) then
if Ekind (T) = E_String_Literal_Subtype then
Set_Small_Size (Component_Size (T) * String_Literal_Length (T));
return True;
elsif not Is_Constrained (T) then
return False;
-- Don't do any recursion on type with error posted, since
-- we may have a malformed type that leads us into a loop
elsif Error_Posted (T) then
return False;
elsif not Size_Known (Component_Type (T)) then
return False;
end if;
-- Check for all indexes static, and also compute possible
-- size (in case it is less than 32 and may be packable).
declare
Esiz : Uint := Component_Size (T);
Dim : Uint;
begin
Index := First_Index (T);
while Present (Index) loop
if Nkind (Index) = N_Range then
Get_Index_Bounds (Index, Low, High);
elsif Error_Posted (Scalar_Range (Etype (Index))) then
return False;
else
Low := Type_Low_Bound (Etype (Index));
High := Type_High_Bound (Etype (Index));
end if;
if not Compile_Time_Known_Value (Low)
or else not Compile_Time_Known_Value (High)
or else Etype (Index) = Any_Type
then
return False;
else
Dim := Expr_Value (High) - Expr_Value (Low) + 1;
if Dim >= 0 then
Esiz := Esiz * Dim;
else
Esiz := Uint_0;
end if;
end if;
Next_Index (Index);
end loop;
Set_Small_Size (Esiz);
return True;
end;
elsif Is_Access_Type (T) then
return True;
elsif Is_Private_Type (T)
and then not Is_Generic_Type (T)
and then Present (Underlying_Type (T))
then
-- Don't do any recursion on type with error posted, since
-- we may have a malformed type that leads us into a loop
if Error_Posted (T) then
return False;
else
return Size_Known (Underlying_Type (T));
end if;
elsif Is_Record_Type (T) then
-- A class-wide type is never considered to have a known size
if Is_Class_Wide_Type (T) then
return False;
-- A subtype of a variant record must not have non-static
-- discriminanted components.
elsif T /= Base_Type (T)
and then not Static_Discriminated_Components (T)
then
return False;
-- Don't do any recursion on type with error posted, since
-- we may have a malformed type that leads us into a loop
elsif Error_Posted (T) then
return False;
end if;
-- Now look at the components of the record
declare
-- The following two variables are used to keep track of
-- the size of packed records if we can tell the size of
-- the packed record in the front end. Packed_Size_Known
-- is True if so far we can figure out the size. It is
-- initialized to True for a packed record, unless the
-- record has discriminants. The reason we eliminate the
-- discriminated case is that we don't know the way the
-- back end lays out discriminated packed records. If
-- Packed_Size_Known is True, then Packed_Size is the
-- size in bits so far.
Packed_Size_Known : Boolean :=
Is_Packed (T)
and then not Has_Discriminants (T);
Packed_Size : Uint := Uint_0;
begin
-- Test for variant part present
if Has_Discriminants (T)
and then Present (Parent (T))
and then Nkind (Parent (T)) = N_Full_Type_Declaration
and then Nkind (Type_Definition (Parent (T))) =
N_Record_Definition
and then not Null_Present (Type_Definition (Parent (T)))
and then Present (Variant_Part
(Component_List (Type_Definition (Parent (T)))))
then
-- If variant part is present, and type is unconstrained,
-- then we must have defaulted discriminants, or a size
-- clause must be present for the type, or else the size
-- is definitely not known at compile time.
if not Is_Constrained (T)
and then
No (Discriminant_Default_Value
(First_Discriminant (T)))
and then Unknown_Esize (T)
then
return False;
end if;
end if;
-- Loop through components
Comp := First_Entity (T);
while Present (Comp) loop
if Ekind (Comp) = E_Component
or else
Ekind (Comp) = E_Discriminant
then
Ctyp := Etype (Comp);
-- We do not know the packed size if there is a
-- component clause present (we possibly could,
-- but this would only help in the case of a record
-- with partial rep clauses. That's because in the
-- case of full rep clauses, the size gets figured
-- out anyway by a different circuit).
if Present (Component_Clause (Comp)) then
Packed_Size_Known := False;
end if;
-- We need to identify a component that is an array
-- where the index type is an enumeration type with
-- non-standard representation, and some bound of the
-- type depends on a discriminant.
-- This is because gigi computes the size by doing a
-- substituation of the appropriate discriminant value
-- in the size expression for the base type, and gigi
-- is not clever enough to evaluate the resulting
-- expression (which involves a call to rep_to_pos)
-- at compile time.
-- It would be nice if gigi would either recognize that
-- this expression can be computed at compile time, or
-- alternatively figured out the size from the subtype
-- directly, where all the information is at hand ???
if Is_Array_Type (Etype (Comp))
and then Present (Packed_Array_Type (Etype (Comp)))
then
declare
Ocomp : constant Entity_Id :=
Original_Record_Component (Comp);
OCtyp : constant Entity_Id := Etype (Ocomp);
Ind : Node_Id;
Indtyp : Entity_Id;
Lo, Hi : Node_Id;
begin
Ind := First_Index (OCtyp);
while Present (Ind) loop
Indtyp := Etype (Ind);
if Is_Enumeration_Type (Indtyp)
and then Has_Non_Standard_Rep (Indtyp)
then
Lo := Type_Low_Bound (Indtyp);
Hi := Type_High_Bound (Indtyp);
if Is_Entity_Name (Lo)
and then
Ekind (Entity (Lo)) = E_Discriminant
then
return False;
elsif Is_Entity_Name (Hi)
and then
Ekind (Entity (Hi)) = E_Discriminant
then
return False;
end if;
end if;
Next_Index (Ind);
end loop;
end;
end if;
-- Clearly size of record is not known if the size of
-- one of the components is not known.
if not Size_Known (Ctyp) then
return False;
end if;
-- Accumulate packed size if possible
if Packed_Size_Known then
-- We can only deal with elementary types, since for
-- non-elementary components, alignment enters into
-- the picture, and we don't know enough to handle
-- proper alignment in this context. Packed arrays
-- count as elementary if the representation is a
-- modular type.
if Is_Elementary_Type (Ctyp)
or else (Is_Array_Type (Ctyp)
and then
Present (Packed_Array_Type (Ctyp))
and then
Is_Modular_Integer_Type
(Packed_Array_Type (Ctyp)))
then
-- If RM_Size is known and static, then we can
-- keep accumulating the packed size.
if Known_Static_RM_Size (Ctyp) then
-- A little glitch, to be removed sometime ???
-- gigi does not understand zero sizes yet.
if RM_Size (Ctyp) = Uint_0 then
Packed_Size_Known := False;
-- Normal case where we can keep accumulating
-- the packed array size.
else
Packed_Size := Packed_Size + RM_Size (Ctyp);
end if;
-- If we have a field whose RM_Size is not known
-- then we can't figure out the packed size here.
else
Packed_Size_Known := False;
end if;
-- If we have a non-elementary type we can't figure
-- out the packed array size (alignment issues).
else
Packed_Size_Known := False;
end if;
end if;
end if;
Next_Entity (Comp);
end loop;
if Packed_Size_Known then
Set_Small_Size (Packed_Size);
end if;
return True;
end;
else
return False;
end if;
end Size_Known;
-------------------------------------
-- Static_Discriminated_Components --
-------------------------------------
function Static_Discriminated_Components
(T : Entity_Id)
return Boolean
is
Constraint : Elmt_Id;
begin
if Has_Discriminants (T)
and then Present (Discriminant_Constraint (T))
and then Present (First_Component (T))
then
Constraint := First_Elmt (Discriminant_Constraint (T));
while Present (Constraint) loop
if not Compile_Time_Known_Value (Node (Constraint)) then
return False;
end if;
Next_Elmt (Constraint);
end loop;
end if;
return True;
end Static_Discriminated_Components;
-- Start of processing for Check_Compile_Time_Size
begin
Set_Size_Known_At_Compile_Time (T, Size_Known (T));
end Check_Compile_Time_Size;
-----------------------------
-- Check_Debug_Info_Needed --
-----------------------------
procedure Check_Debug_Info_Needed (T : Entity_Id) is
begin
if Needs_Debug_Info (T) or else Debug_Info_Off (T) then
return;
elsif Comes_From_Source (T)
or else Debug_Generated_Code
or else Debug_Flag_VV
then
Set_Debug_Info_Needed (T);
end if;
end Check_Debug_Info_Needed;
----------------------------
-- Check_Strict_Alignment --
----------------------------
procedure Check_Strict_Alignment (E : Entity_Id) is
Comp : Entity_Id;
begin
if Is_Tagged_Type (E) or else Is_Concurrent_Type (E) then
Set_Strict_Alignment (E);
elsif Is_Array_Type (E) then
Set_Strict_Alignment (E, Strict_Alignment (Component_Type (E)));
elsif Is_Record_Type (E) then
if Is_Limited_Record (E) then
Set_Strict_Alignment (E);
return;
end if;
Comp := First_Component (E);
while Present (Comp) loop
if not Is_Type (Comp)
and then (Strict_Alignment (Etype (Comp))
or else Is_Aliased (Comp))
then
Set_Strict_Alignment (E);
return;
end if;
Next_Component (Comp);
end loop;
end if;
end Check_Strict_Alignment;
-------------------------
-- Check_Unsigned_Type --
-------------------------
procedure Check_Unsigned_Type (E : Entity_Id) is
Ancestor : Entity_Id;
Lo_Bound : Node_Id;
Btyp : Entity_Id;
begin
if not Is_Discrete_Or_Fixed_Point_Type (E) then
return;
end if;
-- Do not attempt to analyze case where range was in error
if Error_Posted (Scalar_Range (E)) then
return;
end if;
-- The situation that is non trivial is something like
-- subtype x1 is integer range -10 .. +10;
-- subtype x2 is x1 range 0 .. V1;
-- subtype x3 is x2 range V2 .. V3;
-- subtype x4 is x3 range V4 .. V5;
-- where Vn are variables. Here the base type is signed, but we still
-- know that x4 is unsigned because of the lower bound of x2.
-- The only way to deal with this is to look up the ancestor chain
Ancestor := E;
loop
if Ancestor = Any_Type or else Etype (Ancestor) = Any_Type then
return;
end if;
Lo_Bound := Type_Low_Bound (Ancestor);
if Compile_Time_Known_Value (Lo_Bound) then
if Expr_Rep_Value (Lo_Bound) >= 0 then
Set_Is_Unsigned_Type (E, True);
end if;
return;
else
Ancestor := Ancestor_Subtype (Ancestor);
-- If no ancestor had a static lower bound, go to base type
if No (Ancestor) then
-- Note: the reason we still check for a compile time known
-- value for the base type is that at least in the case of
-- generic formals, we can have bounds that fail this test,
-- and there may be other cases in error situations.
Btyp := Base_Type (E);
if Btyp = Any_Type or else Etype (Btyp) = Any_Type then
return;
end if;
Lo_Bound := Type_Low_Bound (Base_Type (E));
if Compile_Time_Known_Value (Lo_Bound)
and then Expr_Rep_Value (Lo_Bound) >= 0
then
Set_Is_Unsigned_Type (E, True);
end if;
return;
end if;
end if;
end loop;
end Check_Unsigned_Type;
-----------------------------
-- Expand_Atomic_Aggregate --
-----------------------------
procedure Expand_Atomic_Aggregate (E : Entity_Id; Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (E);
New_N : Node_Id;
Temp : Entity_Id;
begin
if (Nkind (Parent (E)) = N_Object_Declaration
or else Nkind (Parent (E)) = N_Assignment_Statement)
and then Comes_From_Source (Parent (E))
and then Nkind (E) = N_Aggregate
then
Temp :=
Make_Defining_Identifier (Loc,
New_Internal_Name ('T'));
New_N :=
Make_Object_Declaration (Loc,
Defining_Identifier => Temp,
Object_definition => New_Occurrence_Of (Typ, Loc),
Expression => Relocate_Node (E));
Insert_Before (Parent (E), New_N);
Analyze (New_N);
Set_Expression (Parent (E), New_Occurrence_Of (Temp, Loc));
-- To prevent the temporary from being constant-folded (which
-- would lead to the same piecemeal assignment on the original
-- target) indicate to the back-end that the temporary is a
-- variable with real storage. See description of this flag
-- in Einfo, and the notes on N_Assignment_Statement and
-- N_Object_Declaration in Sinfo.
Set_Is_True_Constant (Temp, False);
end if;
end Expand_Atomic_Aggregate;
----------------
-- Freeze_All --
----------------
-- Note: the easy coding for this procedure would be to just build a
-- single list of freeze nodes and then insert them and analyze them
-- all at once. This won't work, because the analysis of earlier freeze
-- nodes may recursively freeze types which would otherwise appear later
-- on in the freeze list. So we must analyze and expand the freeze nodes
-- as they are generated.
procedure Freeze_All (From : Entity_Id; After : in out Node_Id) is
Loc : constant Source_Ptr := Sloc (After);
E : Entity_Id;
Decl : Node_Id;
procedure Freeze_All_Ent (From : Entity_Id; After : in out Node_Id);
-- This is the internal recursive routine that does freezing of
-- entities (but NOT the analysis of default expressions, which
-- should not be recursive, we don't want to analyze those till
-- we are sure that ALL the types are frozen).
--------------------
-- Freeze_All_Ent --
--------------------
procedure Freeze_All_Ent
(From : Entity_Id;
After : in out Node_Id)
is
E : Entity_Id;
Flist : List_Id;
Lastn : Node_Id;
procedure Process_Flist;
-- If freeze nodes are present, insert and analyze, and reset
-- cursor for next insertion.
-------------------
-- Process_Flist --
-------------------
procedure Process_Flist is
begin
if Is_Non_Empty_List (Flist) then
Lastn := Next (After);
Insert_List_After_And_Analyze (After, Flist);
if Present (Lastn) then
After := Prev (Lastn);
else
After := Last (List_Containing (After));
end if;
end if;
end Process_Flist;
-- Start or processing for Freeze_All_Ent
begin
E := From;
while Present (E) loop
-- If the entity is an inner package which is not a package
-- renaming, then its entities must be frozen at this point.
-- Note that such entities do NOT get frozen at the end of
-- the nested package itself (only library packages freeze).
-- Same is true for task declarations, where anonymous records
-- created for entry parameters must be frozen.
if Ekind (E) = E_Package
and then No (Renamed_Object (E))
and then not Is_Child_Unit (E)
and then not Is_Frozen (E)
then
New_Scope (E);
Install_Visible_Declarations (E);
Install_Private_Declarations (E);
Freeze_All (First_Entity (E), After);
End_Package_Scope (E);
elsif Ekind (E) in Task_Kind
and then
(Nkind (Parent (E)) = N_Task_Type_Declaration
or else
Nkind (Parent (E)) = N_Single_Task_Declaration)
then
New_Scope (E);
Freeze_All (First_Entity (E), After);
End_Scope;
-- For a derived tagged type, we must ensure that all the
-- primitive operations of the parent have been frozen, so
-- that their addresses will be in the parent's dispatch table
-- at the point it is inherited.
elsif Ekind (E) = E_Record_Type
and then Is_Tagged_Type (E)
and then Is_Tagged_Type (Etype (E))
and then Is_Derived_Type (E)
then
declare
Prim_List : constant Elist_Id :=
Primitive_Operations (Etype (E));
Prim : Elmt_Id;
Subp : Entity_Id;
begin
Prim := First_Elmt (Prim_List);
while Present (Prim) loop
Subp := Node (Prim);
if Comes_From_Source (Subp)
and then not Is_Frozen (Subp)
then
Flist := Freeze_Entity (Subp, Loc);
Process_Flist;
end if;
Next_Elmt (Prim);
end loop;
end;
end if;
if not Is_Frozen (E) then
Flist := Freeze_Entity (E, Loc);
Process_Flist;
end if;
-- If an incomplete type is still not frozen, this may be
-- a premature freezing because of a body declaration that
-- follows. Indicate where the freezing took place.
-- If the freezing is caused by the end of the current
-- declarative part, it is a Taft Amendment type, and there
-- is no error.
if not Is_Frozen (E)
and then Ekind (E) = E_Incomplete_Type
then
declare
Bod : constant Node_Id := Next (After);
begin
if (Nkind (Bod) = N_Subprogram_Body
or else Nkind (Bod) = N_Entry_Body
or else Nkind (Bod) = N_Package_Body
or else Nkind (Bod) = N_Protected_Body
or else Nkind (Bod) = N_Task_Body
or else Nkind (Bod) in N_Body_Stub)
and then
List_Containing (After) = List_Containing (Parent (E))
then
Error_Msg_Sloc := Sloc (Next (After));
Error_Msg_NE
("type& is frozen# before its full declaration",
Parent (E), E);
end if;
end;
end if;
Next_Entity (E);
end loop;
end Freeze_All_Ent;
-- Start of processing for Freeze_All
begin
Freeze_All_Ent (From, After);
-- Now that all types are frozen, we can deal with default expressions
-- that require us to build a default expression functions. This is the
-- point at which such functions are constructed (after all types that
-- might be used in such expressions have been frozen).
-- We also add finalization chains to access types whose designated
-- types are controlled. This is normally done when freezing the type,
-- but this misses recursive type definitions where the later members
-- of the recursion introduce controlled components (e.g. 5624-001).
-- Loop through entities
E := From;
while Present (E) loop
if Is_Subprogram (E) then
if not Default_Expressions_Processed (E) then
Process_Default_Expressions (E, After);
end if;
if not Has_Completion (E) then
Decl := Unit_Declaration_Node (E);
if Nkind (Decl) = N_Subprogram_Renaming_Declaration then
Build_And_Analyze_Renamed_Body (Decl, E, After);
elsif Nkind (Decl) = N_Subprogram_Declaration
and then Present (Corresponding_Body (Decl))
and then
Nkind (Unit_Declaration_Node (Corresponding_Body (Decl)))
= N_Subprogram_Renaming_Declaration
then
Build_And_Analyze_Renamed_Body
(Decl, Corresponding_Body (Decl), After);
end if;
end if;
elsif Ekind (E) in Task_Kind
and then
(Nkind (Parent (E)) = N_Task_Type_Declaration
or else
Nkind (Parent (E)) = N_Single_Task_Declaration)
then
declare
Ent : Entity_Id;
begin
Ent := First_Entity (E);
while Present (Ent) loop
if Is_Entry (Ent)
and then not Default_Expressions_Processed (Ent)
then
Process_Default_Expressions (Ent, After);
end if;
Next_Entity (Ent);
end loop;
end;
elsif Is_Access_Type (E)
and then Comes_From_Source (E)
and then Ekind (Directly_Designated_Type (E)) = E_Incomplete_Type
and then Controlled_Type (Designated_Type (E))
and then No (Associated_Final_Chain (E))
then
Build_Final_List (Parent (E), E);
end if;
Next_Entity (E);
end loop;
end Freeze_All;
-----------------------
-- Freeze_And_Append --
-----------------------
procedure Freeze_And_Append
(Ent : Entity_Id;
Loc : Source_Ptr;
Result : in out List_Id)
is
L : constant List_Id := Freeze_Entity (Ent, Loc);
begin
if Is_Non_Empty_List (L) then
if Result = No_List then
Result := L;
else
Append_List (L, Result);
end if;
end if;
end Freeze_And_Append;
-------------------
-- Freeze_Before --
-------------------
procedure Freeze_Before (N : Node_Id; T : Entity_Id) is
Freeze_Nodes : constant List_Id := Freeze_Entity (T, Sloc (N));
begin
if Is_Non_Empty_List (Freeze_Nodes) then
Insert_Actions (N, Freeze_Nodes);
end if;
end Freeze_Before;
-------------------
-- Freeze_Entity --
-------------------
function Freeze_Entity (E : Entity_Id; Loc : Source_Ptr) return List_Id is
Comp : Entity_Id;
F_Node : Node_Id;
Result : List_Id;
Indx : Node_Id;
Formal : Entity_Id;
Atype : Entity_Id;
procedure Check_Current_Instance (Comp_Decl : Node_Id);
-- Check that an Access or Unchecked_Access attribute with
-- a prefix which is the current instance type can only be
-- applied when the type is limited.
function After_Last_Declaration return Boolean;
-- If Loc is a freeze_entity that appears after the last declaration
-- in the scope, inhibit error messages on late completion.
procedure Freeze_Record_Type (Rec : Entity_Id);
-- Freeze each component, handle some representation clauses, and
-- freeze primitive operations if this is a tagged type.
----------------------------
-- After_Last_Declaration --
----------------------------
function After_Last_Declaration return Boolean is
Spec : constant Node_Id := Parent (Current_Scope);
begin
if Nkind (Spec) = N_Package_Specification then
if Present (Private_Declarations (Spec)) then
return Loc >= Sloc (Last (Private_Declarations (Spec)));
elsif Present (Visible_Declarations (Spec)) then
return Loc >= Sloc (Last (Visible_Declarations (Spec)));
else
return False;
end if;
else
return False;
end if;
end After_Last_Declaration;
----------------------------
-- Check_Current_Instance --
----------------------------
procedure Check_Current_Instance (Comp_Decl : Node_Id) is
function Process (N : Node_Id) return Traverse_Result;
-- Process routine to apply check to given node.
-------------
-- Process --
-------------
function Process (N : Node_Id) return Traverse_Result is
begin
case Nkind (N) is
when N_Attribute_Reference =>
if (Attribute_Name (N) = Name_Access
or else
Attribute_Name (N) = Name_Unchecked_Access)
and then Is_Entity_Name (Prefix (N))
and then Is_Type (Entity (Prefix (N)))
and then Entity (Prefix (N)) = E
then
Error_Msg_N
("current instance must be a limited type", Prefix (N));
return Abandon;
else
return OK;
end if;
when others => return OK;
end case;
end Process;
procedure Traverse is new Traverse_Proc (Process);
-- Start of processing for Check_Current_Instance
begin
Traverse (Comp_Decl);
end Check_Current_Instance;
------------------------
-- Freeze_Record_Type --
------------------------
procedure Freeze_Record_Type (Rec : Entity_Id) is
Comp : Entity_Id;
IR : Node_Id;
Junk : Boolean;
ADC : Node_Id;
Unplaced_Component : Boolean := False;
-- Set True if we find at least one component with no component
-- clause (used to warn about useless Pack pragmas).
Placed_Component : Boolean := False;
-- Set True if we find at least one component with a component
-- clause (used to warn about useless Bit_Order pragmas).
begin
-- If this is a subtype of a controlled type, declared without
-- a constraint, the _controller may not appear in the component
-- list if the parent was not frozen at the point of subtype
-- declaration. Inherit the _controller component now.
if Rec /= Base_Type (Rec)
and then Has_Controlled_Component (Rec)
then
if Nkind (Parent (Rec)) = N_Subtype_Declaration
and then Is_Entity_Name (Subtype_Indication (Parent (Rec)))
then
Set_First_Entity (Rec, First_Entity (Base_Type (Rec)));
-- If this is an internal type without a declaration, as for
-- a record component, the base type may not yet be frozen,
-- and its controller has not been created. Add an explicit
-- freeze node for the itype, so it will be frozen after the
-- base type.
elsif Is_Itype (Rec)
and then Has_Delayed_Freeze (Base_Type (Rec))
and then
Nkind (Associated_Node_For_Itype (Rec)) =
N_Component_Declaration
then
Ensure_Freeze_Node (Rec);
end if;
end if;
-- Freeze components and embedded subtypes
Comp := First_Entity (Rec);
while Present (Comp) loop
if not Is_Type (Comp) then
Freeze_And_Append (Etype (Comp), Loc, Result);
end if;
-- If the component is an access type with an allocator
-- as default value, the designated type will be frozen
-- by the corresponding expression in init_proc. In order
-- to place the freeze node for the designated type before
-- that for the current record type, freeze it now.
-- Same process if the component is an array of access types,
-- initialized with an aggregate. If the designated type is
-- private, it cannot contain allocators, and it is premature
-- to freeze the type, so we check for this as well.
if Is_Access_Type (Etype (Comp))
and then Present (Parent (Comp))
and then Present (Expression (Parent (Comp)))
and then Nkind (Expression (Parent (Comp))) = N_Allocator
then
declare
Alloc : constant Node_Id := Expression (Parent (Comp));
begin
-- If component is pointer to a classwide type, freeze
-- the specific type in the expression being allocated.
-- The expression may be a subtype indication, in which
-- case freeze the subtype mark.
if Is_Class_Wide_Type (Designated_Type (Etype (Comp))) then
if Is_Entity_Name (Expression (Alloc)) then
Freeze_And_Append
(Entity (Expression (Alloc)), Loc, Result);
elsif
Nkind (Expression (Alloc)) = N_Subtype_Indication
then
Freeze_And_Append
(Entity (Subtype_Mark (Expression (Alloc))),
Loc, Result);
end if;
else
Freeze_And_Append
(Designated_Type (Etype (Comp)), Loc, Result);
end if;
end;
-- If this is a constrained subtype of an already frozen type,
-- make the subtype frozen as well. It might otherwise be frozen
-- in the wrong scope, and a freeze node on subtype has no effect.
elsif Is_Access_Type (Etype (Comp))
and then not Is_Frozen (Designated_Type (Etype (Comp)))
and then Is_Itype (Designated_Type (Etype (Comp)))
and then Is_Frozen (Base_Type (Designated_Type (Etype (Comp))))
then
Set_Is_Frozen (Designated_Type (Etype (Comp)));
-- In addition, add an Itype_Reference to ensure that the
-- access subtype is elaborated early enough. This cannot
-- be done if the subtype may depend on discriminants.
if Ekind (Comp) = E_Component
and then Is_Itype (Etype (Comp))
and then not Has_Discriminants (Rec)
then
IR := Make_Itype_Reference (Sloc (Comp));
Set_Itype (IR, Designated_Type (Etype (Comp)));
if No (Result) then
Result := New_List (IR);
else
Append (IR, Result);
end if;
end if;
elsif Is_Array_Type (Etype (Comp))
and then Is_Access_Type (Component_Type (Etype (Comp)))
and then Present (Parent (Comp))
and then Nkind (Parent (Comp)) = N_Component_Declaration
and then Present (Expression (Parent (Comp)))
and then Nkind (Expression (Parent (Comp))) = N_Aggregate
and then Is_Fully_Defined
(Designated_Type (Component_Type (Etype (Comp))))
then
Freeze_And_Append
(Designated_Type
(Component_Type (Etype (Comp))), Loc, Result);
end if;
-- Processing for real components (exclude anonymous subtypes)
if Ekind (Comp) = E_Component
or else Ekind (Comp) = E_Discriminant
then
-- Check for error of component clause given for variable
-- sized type. We have to delay this test till this point,
-- since the component type has to be frozen for us to know
-- if it is variable length. We omit this test in a generic
-- context, it will be applied at instantiation time.
declare
CC : constant Node_Id := Component_Clause (Comp);
begin
if Present (CC) then
Placed_Component := True;
if Inside_A_Generic then
null;
elsif not Size_Known_At_Compile_Time
(Underlying_Type (Etype (Comp)))
then
Error_Msg_N
("component clause not allowed for variable " &
"length component", CC);
end if;
else
Unplaced_Component := True;
end if;
end;
-- If component clause is present, then deal with the
-- non-default bit order case. We cannot do this before
-- the freeze point, because there is no required order
-- for the component clause and the bit_order clause.
-- We only do this processing for the base type, and in
-- fact that's important, since otherwise if there are
-- record subtypes, we could reverse the bits once for
-- each subtype, which would be incorrect.
if Present (Component_Clause (Comp))
and then Reverse_Bit_Order (Rec)
and then Ekind (E) = E_Record_Type
then
declare
CFB : constant Uint := Component_Bit_Offset (Comp);
CSZ : constant Uint := Esize (Comp);
CLC : constant Node_Id := Component_Clause (Comp);
Pos : constant Node_Id := Position (CLC);
FB : constant Node_Id := First_Bit (CLC);
Storage_Unit_Offset : constant Uint :=
CFB / System_Storage_Unit;
Start_Bit : constant Uint :=
CFB mod System_Storage_Unit;
begin
-- Cases where field goes over storage unit boundary
if Start_Bit + CSZ > System_Storage_Unit then
-- Allow multi-byte field but generate warning
if Start_Bit mod System_Storage_Unit = 0
and then CSZ mod System_Storage_Unit = 0
then
Error_Msg_N
("multi-byte field specified with non-standard"
& " Bit_Order?", CLC);
if Bytes_Big_Endian then
Error_Msg_N
("bytes are not reversed "
& "(component is big-endian)?", CLC);
else
Error_Msg_N
("bytes are not reversed "
& "(component is little-endian)?", CLC);
end if;
-- Do not allow non-contiguous field
else
Error_Msg_N
("attempt to specify non-contiguous field"
& " not permitted", CLC);
Error_Msg_N
("\(caused by non-standard Bit_Order "
& "specified)", CLC);
end if;
-- Case where field fits in one storage unit
else
-- Give warning if suspicious component clause
if Intval (FB) >= System_Storage_Unit then
Error_Msg_N
("?Bit_Order clause does not affect " &
"byte ordering", Pos);
Error_Msg_Uint_1 :=
Intval (Pos) + Intval (FB) / System_Storage_Unit;
Error_Msg_N
("?position normalized to ^ before bit " &
"order interpreted", Pos);
end if;
-- Here is where we fix up the Component_Bit_Offset
-- value to account for the reverse bit order.
-- Some examples of what needs to be done are:
-- First_Bit .. Last_Bit Component_Bit_Offset
-- old new old new
-- 0 .. 0 7 .. 7 0 7
-- 0 .. 1 6 .. 7 0 6
-- 0 .. 2 5 .. 7 0 5
-- 0 .. 7 0 .. 7 0 4
-- 1 .. 1 6 .. 6 1 6
-- 1 .. 4 3 .. 6 1 3
-- 4 .. 7 0 .. 3 4 0
-- The general rule is that the first bit is
-- is obtained by subtracting the old ending bit
-- from storage_unit - 1.
Set_Component_Bit_Offset (Comp,
(Storage_Unit_Offset * System_Storage_Unit)
+ (System_Storage_Unit - 1)
- (Start_Bit + CSZ - 1));
Set_Normalized_First_Bit (Comp,
Component_Bit_Offset (Comp) mod System_Storage_Unit);
end if;
end;
end if;
end if;
Next_Entity (Comp);
end loop;
-- Check for useless pragma Bit_Order
if not Placed_Component and then Reverse_Bit_Order (Rec) then
ADC := Get_Attribute_Definition_Clause (Rec, Attribute_Bit_Order);
Error_Msg_N ("?Bit_Order specification has no effect", ADC);
Error_Msg_N ("\?since no component clauses were specified", ADC);
end if;
-- Check for useless pragma Pack when all components placed
if Is_Packed (Rec)
and then not Unplaced_Component
and then Warn_On_Redundant_Constructs
then
Error_Msg_N
("?pragma Pack has no effect, no unplaced components",
Get_Rep_Pragma (Rec, Name_Pack));
Set_Is_Packed (Rec, False);
end if;
-- If this is the record corresponding to a remote type,
-- freeze the remote type here since that is what we are
-- semantically freezing. This prevents having the freeze
-- node for that type in an inner scope.
-- Also, Check for controlled components and unchecked unions.
-- Finally, enforce the restriction that access attributes with
-- a current instance prefix can only apply to limited types.
if Ekind (Rec) = E_Record_Type then
if Present (Corresponding_Remote_Type (Rec)) then
Freeze_And_Append
(Corresponding_Remote_Type (Rec), Loc, Result);
end if;
Comp := First_Component (Rec);
while Present (Comp) loop
if Has_Controlled_Component (Etype (Comp))
or else (Chars (Comp) /= Name_uParent
and then Is_Controlled (Etype (Comp)))
or else (Is_Protected_Type (Etype (Comp))
and then Present
(Corresponding_Record_Type (Etype (Comp)))
and then Has_Controlled_Component
(Corresponding_Record_Type (Etype (Comp))))
then
Set_Has_Controlled_Component (Rec);
exit;
end if;
if Has_Unchecked_Union (Etype (Comp)) then
Set_Has_Unchecked_Union (Rec);
end if;
if Has_Per_Object_Constraint (Comp)
and then not Is_Limited_Type (Rec)
then
-- Scan component declaration for likely misuses of
-- current instance, either in a constraint or in a
-- default expression.
Check_Current_Instance (Parent (Comp));
end if;
Next_Component (Comp);
end loop;
end if;
Set_Component_Alignment_If_Not_Set (Rec);
-- For first subtypes, check if there are any fixed-point
-- fields with component clauses, where we must check the size.
-- This is not done till the freeze point, since for fixed-point
-- types, we do not know the size until the type is frozen.
-- Similar processing applies to bit packed arrays.
if Is_First_Subtype (Rec) then
Comp := First_Component (Rec);
while Present (Comp) loop
if Present (Component_Clause (Comp))
and then (Is_Fixed_Point_Type (Etype (Comp))
or else
Is_Bit_Packed_Array (Etype (Comp)))
then
Check_Size
(Component_Name (Component_Clause (Comp)),
Etype (Comp),
Esize (Comp),
Junk);
end if;
Next_Component (Comp);
end loop;
end if;
end Freeze_Record_Type;
-- Start of processing for Freeze_Entity
begin
-- Do not freeze if already frozen since we only need one freeze node
if Is_Frozen (E) then
return No_List;
-- It is improper to freeze an external entity within a generic
-- because its freeze node will appear in a non-valid context.
-- ??? We should probably freeze the entity at that point and insert
-- the freeze node in a proper place but this proper place is not
-- easy to find, and the proper scope is not easy to restore. For
-- now, just wait to get out of the generic to freeze ???
elsif Inside_A_Generic and then External_Ref_In_Generic (E) then
return No_List;
-- Do not freeze a global entity within an inner scope created during
-- expansion. A call to subprogram E within some internal procedure
-- (a stream attribute for example) might require freezing E, but the
-- freeze node must appear in the same declarative part as E itself.
-- The two-pass elaboration mechanism in gigi guarantees that E will
-- be frozen before the inner call is elaborated. We exclude constants
-- from this test, because deferred constants may be frozen early, and
-- must be diagnosed (see e.g. 1522-005). If the enclosing subprogram
-- comes from source, or is a generic instance, then the freeze point
-- is the one mandated by the language. and we freze the entity.
elsif In_Open_Scopes (Scope (E))
and then Scope (E) /= Current_Scope
and then Ekind (E) /= E_Constant
then
declare
S : Entity_Id := Current_Scope;
begin
while Present (S) loop
if Is_Overloadable (S) then
if Comes_From_Source (S)
or else Is_Generic_Instance (S)
then
exit;
else
return No_List;
end if;
end if;
S := Scope (S);
end loop;
end;
end if;
-- Here to freeze the entity
Result := No_List;
Set_Is_Frozen (E);
-- Case of entity being frozen is other than a type
if not Is_Type (E) then
-- If entity is exported or imported and does not have an external
-- name, now is the time to provide the appropriate default name.
-- Skip this if the entity is stubbed, since we don't need a name
-- for any stubbed routine.
if (Is_Imported (E) or else Is_Exported (E))
and then No (Interface_Name (E))
and then Convention (E) /= Convention_Stubbed
then
Set_Encoded_Interface_Name
(E, Get_Default_External_Name (E));
-- Special processing for atomic objects appearing in object decls
elsif Is_Atomic (E)
and then Nkind (Parent (E)) = N_Object_Declaration
and then Present (Expression (Parent (E)))
then
declare
Expr : constant Node_Id := Expression (Parent (E));
begin
-- If expression is an aggregate, assign to a temporary to
-- ensure that the actual assignment is done atomically rather
-- than component-wise (the assignment to the temp may be done
-- component-wise, but that is harmless.
if Nkind (Expr) = N_Aggregate then
Expand_Atomic_Aggregate (Expr, Etype (E));
-- If the expression is a reference to a record or array
-- object entity, then reset Is_True_Constant to False so
-- that the compiler will not optimize away the intermediate
-- object, which we need in this case for the same reason
-- (to ensure that the actual assignment is atomic, rather
-- than component-wise).
elsif Is_Entity_Name (Expr)
and then (Is_Record_Type (Etype (Expr))
or else
Is_Array_Type (Etype (Expr)))
then
Set_Is_True_Constant (Entity (Expr), False);
end if;
end;
end if;
-- For a subprogram, freeze all parameter types and also the return
-- type (RM 13.14(14)). However skip this for internal subprograms.
-- This is also the point where any extra formal parameters are
-- created since we now know whether the subprogram will use
-- a foreign convention.
if Is_Subprogram (E) then
if not Is_Internal (E) then
declare
F_Type : Entity_Id;
function Is_Fat_C_Ptr_Type (T : Entity_Id) return Boolean;
-- Determines if given type entity is a fat pointer type
-- used as an argument type or return type to a subprogram
-- with C or C++ convention set.
--------------------------
-- Is_Fat_C_Access_Type --
--------------------------
function Is_Fat_C_Ptr_Type (T : Entity_Id) return Boolean is
begin
return (Convention (E) = Convention_C
or else
Convention (E) = Convention_CPP)
and then Is_Access_Type (T)
and then Esize (T) > Ttypes.System_Address_Size;
end Is_Fat_C_Ptr_Type;
begin
-- Loop through formals
Formal := First_Formal (E);
while Present (Formal) loop
F_Type := Etype (Formal);
Freeze_And_Append (F_Type, Loc, Result);
if Is_Private_Type (F_Type)
and then Is_Private_Type (Base_Type (F_Type))
and then No (Full_View (Base_Type (F_Type)))
and then not Is_Generic_Type (F_Type)
and then not Is_Derived_Type (F_Type)
then
-- If the type of a formal is incomplete, subprogram
-- is being frozen prematurely. Within an instance
-- (but not within a wrapper package) this is an
-- an artifact of our need to regard the end of an
-- instantiation as a freeze point. Otherwise it is
-- a definite error.
-- and then not Is_Wrapper_Package (Current_Scope) ???
if In_Instance then
Set_Is_Frozen (E, False);
return No_List;
elsif not After_Last_Declaration then
Error_Msg_Node_1 := F_Type;
Error_Msg
("type& must be fully defined before this point",
Loc);
end if;
end if;
-- Check bad use of fat C pointer
if Warn_On_Export_Import and then
Is_Fat_C_Ptr_Type (F_Type)
then
Error_Msg_Qual_Level := 1;
Error_Msg_N
("?type of & does not correspond to C pointer",
Formal);
Error_Msg_Qual_Level := 0;
end if;
-- Check for unconstrained array in exported foreign
-- convention case.
if Convention (E) in Foreign_Convention
and then not Is_Imported (E)
and then Is_Array_Type (F_Type)
and then not Is_Constrained (F_Type)
and then Warn_On_Export_Import
then
Error_Msg_Qual_Level := 1;
Error_Msg_N
("?type of argument& is unconstrained array",
Formal);
Error_Msg_N
("?foreign caller must pass bounds explicitly",
Formal);
Error_Msg_Qual_Level := 0;
end if;
Next_Formal (Formal);
end loop;
-- Check return type
if Ekind (E) = E_Function then
Freeze_And_Append (Etype (E), Loc, Result);
if Warn_On_Export_Import
and then Is_Fat_C_Ptr_Type (Etype (E))
then
Error_Msg_N
("?return type of& does not correspond to C pointer",
E);
elsif Is_Array_Type (Etype (E))
and then not Is_Constrained (Etype (E))
and then not Is_Imported (E)
and then Convention (E) in Foreign_Convention
and then Warn_On_Export_Import
then
Error_Msg_N
("?foreign convention function& should not " &
"return unconstrained array", E);
end if;
end if;
end;
end if;
-- Must freeze its parent first if it is a derived subprogram
if Present (Alias (E)) then
Freeze_And_Append (Alias (E), Loc, Result);
end if;
-- If the return type requires a transient scope, and we are on
-- a target allowing functions to return with a depressed stack
-- pointer, then we mark the function as requiring this treatment.
if Ekind (E) = E_Function
and then Functions_Return_By_DSP_On_Target
and then Requires_Transient_Scope (Etype (E))
then
Set_Function_Returns_With_DSP (E);
end if;
if not Is_Internal (E) then
Freeze_Subprogram (E);
end if;
-- Here for other than a subprogram or type
else
-- If entity has a type, and it is not a generic unit, then
-- freeze it first (RM 13.14(10))
if Present (Etype (E))
and then Ekind (E) /= E_Generic_Function
then
Freeze_And_Append (Etype (E), Loc, Result);
end if;
-- For object created by object declaration, perform required
-- categorization (preelaborate and pure) checks. Defer these
-- checks to freeze time since pragma Import inhibits default
-- initialization and thus pragma Import affects these checks.
if Nkind (Declaration_Node (E)) = N_Object_Declaration then
Validate_Object_Declaration (Declaration_Node (E));
Check_Address_Clause (E);
end if;
-- Check that a constant which has a pragma Volatile[_Components]
-- or Atomic[_Components] also has a pragma Import (RM C.6(13))
-- Note: Atomic[_Components] also sets Volatile[_Components]
if Ekind (E) = E_Constant
and then (Has_Volatile_Components (E) or else Is_Volatile (E))
and then not Is_Imported (E)
then
-- Make sure we actually have a pragma, and have not merely
-- inherited the indication from elsewhere (e.g. an address
-- clause, which is not good enough in RM terms!)
if Present (Get_Rep_Pragma (E, Name_Atomic))
or else
Present (Get_Rep_Pragma (E, Name_Atomic_Components))
then
Error_Msg_N
("stand alone atomic constant must be " &
"imported ('R'M 'C.6(13))", E);
elsif Present (Get_Rep_Pragma (E, Name_Volatile))
or else
Present (Get_Rep_Pragma (E, Name_Volatile_Components))
then
Error_Msg_N
("stand alone volatile constant must be " &
"imported ('R'M 'C.6(13))", E);
end if;
end if;
-- Static objects require special handling
if (Ekind (E) = E_Constant or else Ekind (E) = E_Variable)
and then Is_Statically_Allocated (E)
then
Freeze_Static_Object (E);
end if;
-- Remaining step is to layout objects
if Ekind (E) = E_Variable
or else
Ekind (E) = E_Constant
or else
Ekind (E) = E_Loop_Parameter
or else
Is_Formal (E)
then
Layout_Object (E);
end if;
end if;
-- Case of a type or subtype being frozen
else
-- The type may be defined in a generic unit. This can occur when
-- freezing a generic function that returns the type (which is
-- defined in a parent unit). It is clearly meaningless to freeze
-- this type. However, if it is a subtype, its size may be determi-
-- nable and used in subsequent checks, so might as well try to
-- compute it.
if Present (Scope (E))
and then Is_Generic_Unit (Scope (E))
then
Check_Compile_Time_Size (E);
return No_List;
end if;
-- Deal with special cases of freezing for subtype
if E /= Base_Type (E) then
-- If ancestor subtype present, freeze that first.
-- Note that this will also get the base type frozen.
Atype := Ancestor_Subtype (E);
if Present (Atype) then
Freeze_And_Append (Atype, Loc, Result);
-- Otherwise freeze the base type of the entity before
-- freezing the entity itself, (RM 13.14(15)).
elsif E /= Base_Type (E) then
Freeze_And_Append (Base_Type (E), Loc, Result);
end if;
-- For a derived type, freeze its parent type first (RM 13.14(15))
elsif Is_Derived_Type (E) then
Freeze_And_Append (Etype (E), Loc, Result);
Freeze_And_Append (First_Subtype (Etype (E)), Loc, Result);
end if;
-- For array type, freeze index types and component type first
-- before freezing the array (RM 13.14(15)).
if Is_Array_Type (E) then
declare
Ctyp : constant Entity_Id := Component_Type (E);
Pnod : Node_Id;
Non_Standard_Enum : Boolean := False;
-- Set true if any of the index types is an enumeration
-- type with a non-standard representation.
begin
Freeze_And_Append (Ctyp, Loc, Result);
Indx := First_Index (E);
while Present (Indx) loop
Freeze_And_Append (Etype (Indx), Loc, Result);
if Is_Enumeration_Type (Etype (Indx))
and then Has_Non_Standard_Rep (Etype (Indx))
then
Non_Standard_Enum := True;
end if;
Next_Index (Indx);
end loop;
-- Processing that is done only for base types
if Ekind (E) = E_Array_Type then
-- Propagate flags for component type
if Is_Controlled (Component_Type (E))
or else Has_Controlled_Component (Ctyp)
then
Set_Has_Controlled_Component (E);
end if;
if Has_Unchecked_Union (Component_Type (E)) then
Set_Has_Unchecked_Union (E);
end if;
-- If packing was requested or if the component size was set
-- explicitly, then see if bit packing is required. This
-- processing is only done for base types, since all the
-- representation aspects involved are type-related. This
-- is not just an optimization, if we start processing the
-- subtypes, they intefere with the settings on the base
-- type (this is because Is_Packed has a slightly different
-- meaning before and after freezing).
declare
Csiz : Uint;
Esiz : Uint;
begin
if (Is_Packed (E) or else Has_Pragma_Pack (E))
and then not Has_Atomic_Components (E)
and then Known_Static_RM_Size (Ctyp)
then
Csiz := UI_Max (RM_Size (Ctyp), 1);
elsif Known_Component_Size (E) then
Csiz := Component_Size (E);
elsif not Known_Static_Esize (Ctyp) then
Csiz := Uint_0;
else
Esiz := Esize (Ctyp);
-- We can set the component size if it is less than
-- 16, rounding it up to the next storage unit size.
if Esiz <= 8 then
Csiz := Uint_8;
elsif Esiz <= 16 then
Csiz := Uint_16;
else
Csiz := Uint_0;
end if;
-- Set component size up to match alignment if
-- it would otherwise be less than the alignment.
-- This deals with cases of types whose alignment
-- exceeds their sizes (padded types).
if Csiz /= 0 then
declare
A : constant Uint := Alignment_In_Bits (Ctyp);
begin
if Csiz < A then
Csiz := A;
end if;
end;
end if;
end if;
if 1 <= Csiz and then Csiz <= 64 then
-- We set the component size for all cases 1-64
Set_Component_Size (Base_Type (E), Csiz);
-- Check for base type of 8,16,32 bits, where the
-- subtype has a length one less than the base type
-- and is unsigned (e.g. Natural subtype of Integer)
-- In such cases, if a component size was not set
-- explicitly, then generate a warning.
if Has_Pragma_Pack (E)
and then not Has_Component_Size_Clause (E)
and then
(Csiz = 7 or else Csiz = 15 or else Csiz = 31)
and then Esize (Base_Type (Ctyp)) = Csiz + 1
then
Error_Msg_Uint_1 := Csiz;
Pnod :=
Get_Rep_Pragma (First_Subtype (E), Name_Pack);
if Present (Pnod) then
Error_Msg_N
("pragma Pack causes component size to be ^?",
Pnod);
Error_Msg_N
("\use Component_Size to set desired value",
Pnod);
end if;
end if;
-- Actual packing is not needed for 8,16,32,64
-- Also not needed for 24 if alignment is 1
if Csiz = 8
or else Csiz = 16
or else Csiz = 32
or else Csiz = 64
or else (Csiz = 24 and then Alignment (Ctyp) = 1)
then
-- Here the array was requested to be packed, but
-- the packing request had no effect, so Is_Packed
-- is reset.
-- Note: semantically this means that we lose
-- track of the fact that a derived type inherited
-- a pack pragma that was non-effective, but that
-- seems fine.
-- We regard a Pack pragma as a request to set a
-- representation characteristic, and this request
-- may be ignored.
Set_Is_Packed (Base_Type (E), False);
-- In all other cases, packing is indeed needed
else
Set_Has_Non_Standard_Rep (Base_Type (E));
Set_Is_Bit_Packed_Array (Base_Type (E));
Set_Is_Packed (Base_Type (E));
end if;
end if;
end;
-- Processing that is done only for subtypes
else
-- Acquire alignment from base type
if Unknown_Alignment (E) then
Set_Alignment (E, Alignment (Base_Type (E)));
end if;
end if;
-- For bit-packed arrays, check the size
if Is_Bit_Packed_Array (E)
and then Known_Esize (E)
then
declare
Discard : Boolean;
SizC : constant Node_Id := Size_Clause (E);
begin
-- It is not clear if it is possible to have no size
-- clause at this stage, but this is not worth worrying
-- about. Post the error on the entity name in the size
-- clause if present, else on the type entity itself.
if Present (SizC) then
Check_Size (Name (SizC), E, Esize (E), Discard);
else
Check_Size (E, E, Esize (E), Discard);
end if;
end;
end if;
-- Check one common case of a size given where the array
-- needs to be packed, but was not so the size cannot be
-- honored. This would of course be caught by the backend,
-- and indeed we don't catch all cases. The point is that
-- we can give a better error message in those cases that
-- we do catch with the circuitry here.
declare
Lo, Hi : Node_Id;
Ctyp : constant Entity_Id := Component_Type (E);
begin
if Present (Size_Clause (E))
and then Known_Static_Esize (E)
and then not Is_Bit_Packed_Array (E)
and then not Has_Pragma_Pack (E)
and then Number_Dimensions (E) = 1
and then not Has_Component_Size_Clause (E)
and then Known_Static_Esize (Ctyp)
then
Get_Index_Bounds (First_Index (E), Lo, Hi);
if Compile_Time_Known_Value (Lo)
and then Compile_Time_Known_Value (Hi)
and then Known_Static_RM_Size (Ctyp)
and then RM_Size (Ctyp) < 64
then
declare
Lov : constant Uint := Expr_Value (Lo);
Hiv : constant Uint := Expr_Value (Hi);
Len : constant Uint :=
UI_Max (Uint_0, Hiv - Lov + 1);
Rsiz : constant Uint := RM_Size (Ctyp);
-- What we are looking for here is the situation
-- where the Esize given would be exactly right
-- if there was a pragma Pack (resulting in the
-- component size being the same as the RM_Size).
-- Furthermore, the component type size must be
-- an odd size (not a multiple of storage unit)
begin
if Esize (E) = Len * Rsiz
and then Rsiz mod System_Storage_Unit /= 0
then
Error_Msg_NE
("size given for& too small",
Size_Clause (E), E);
Error_Msg_N
("\explicit pragma Pack is required",
Size_Clause (E));
end if;
end;
end if;
end if;
end;
-- If any of the index types was an enumeration type with
-- a non-standard rep clause, then we indicate that the
-- array type is always packed (even if it is not bit packed).
if Non_Standard_Enum then
Set_Has_Non_Standard_Rep (Base_Type (E));
Set_Is_Packed (Base_Type (E));
end if;
end;
Set_Component_Alignment_If_Not_Set (E);
-- If the array is packed, we must create the packed array
-- type to be used to actually implement the type. This is
-- only needed for real array types (not for string literal
-- types, since they are present only for the front end).
if Is_Packed (E)
and then Ekind (E) /= E_String_Literal_Subtype
then
Create_Packed_Array_Type (E);
Freeze_And_Append (Packed_Array_Type (E), Loc, Result);
-- Size information of packed array type is copied to the
-- array type, since this is really the representation.
Set_Size_Info (E, Packed_Array_Type (E));
Set_RM_Size (E, RM_Size (Packed_Array_Type (E)));
end if;
-- For a class-wide type, the corresponding specific type is
-- frozen as well (RM 13.14(15))
elsif Is_Class_Wide_Type (E) then
Freeze_And_Append (Root_Type (E), Loc, Result);
-- If the Class_Wide_Type is an Itype (when type is the anonymous
-- parent of a derived type) and it is a library-level entity,
-- generate an itype reference for it. Otherwise, its first
-- explicit reference may be in an inner scope, which will be
-- rejected by the back-end.
if Is_Itype (E)
and then Is_Compilation_Unit (Scope (E))
then
declare
Ref : constant Node_Id := Make_Itype_Reference (Loc);
begin
Set_Itype (Ref, E);
if No (Result) then
Result := New_List (Ref);
else
Append (Ref, Result);
end if;
end;
end if;
-- The equivalent type associated with a class-wide subtype
-- needs to be frozen to ensure that its layout is done.
-- Class-wide subtypes are currently only frozen on targets
-- requiring front-end layout (see New_Class_Wide_Subtype
-- and Make_CW_Equivalent_Type in exp_util.adb).
if Ekind (E) = E_Class_Wide_Subtype
and then Present (Equivalent_Type (E))
then
Freeze_And_Append (Equivalent_Type (E), Loc, Result);
end if;
-- For a record (sub)type, freeze all the component types (RM
-- 13.14(15). We test for E_Record_(sub)Type here, rather than
-- using Is_Record_Type, because we don't want to attempt the
-- freeze for the case of a private type with record extension
-- (we will do that later when the full type is frozen).
elsif Ekind (E) = E_Record_Type
or else Ekind (E) = E_Record_Subtype
then
Freeze_Record_Type (E);
-- For a concurrent type, freeze corresponding record type. This
-- does not correpond to any specific rule in the RM, but the
-- record type is essentially part of the concurrent type.
-- Freeze as well all local entities. This includes record types
-- created for entry parameter blocks, and whatever local entities
-- may appear in the private part.
elsif Is_Concurrent_Type (E) then
if Present (Corresponding_Record_Type (E)) then
Freeze_And_Append
(Corresponding_Record_Type (E), Loc, Result);
end if;
Comp := First_Entity (E);
while Present (Comp) loop
if Is_Type (Comp) then
Freeze_And_Append (Comp, Loc, Result);
elsif (Ekind (Comp)) /= E_Function then
Freeze_And_Append (Etype (Comp), Loc, Result);
end if;
Next_Entity (Comp);
end loop;
-- Private types are required to point to the same freeze node
-- as their corresponding full views. The freeze node itself
-- has to point to the partial view of the entity (because
-- from the partial view, we can retrieve the full view, but
-- not the reverse). However, in order to freeze correctly,
-- we need to freeze the full view. If we are freezing at the
-- end of a scope (or within the scope of the private type),
-- the partial and full views will have been swapped, the
-- full view appears first in the entity chain and the swapping
-- mechanism ensures that the pointers are properly set (on
-- scope exit).
-- If we encounter the partial view before the full view
-- (e.g. when freezing from another scope), we freeze the
-- full view, and then set the pointers appropriately since
-- we cannot rely on swapping to fix things up (subtypes in an
-- outer scope might not get swapped).
elsif Is_Incomplete_Or_Private_Type (E)
and then not Is_Generic_Type (E)
then
-- Case of full view present
if Present (Full_View (E)) then
-- If full view has already been frozen, then no
-- further processing is required
if Is_Frozen (Full_View (E)) then
Set_Has_Delayed_Freeze (E, False);
Set_Freeze_Node (E, Empty);
Check_Debug_Info_Needed (E);
-- Otherwise freeze full view and patch the pointers
-- so that the freeze node will elaborate both views
-- in the back-end.
else
declare
Full : constant Entity_Id := Full_View (E);
begin
if Is_Private_Type (Full)
and then Present (Underlying_Full_View (Full))
then
Freeze_And_Append
(Underlying_Full_View (Full), Loc, Result);
end if;
Freeze_And_Append (Full, Loc, Result);
if Has_Delayed_Freeze (E) then
F_Node := Freeze_Node (Full);
if Present (F_Node) then
Set_Freeze_Node (E, F_Node);
Set_Entity (F_Node, E);
else
-- {Incomplete,Private}_Subtypes
-- with Full_Views constrained by discriminants
Set_Has_Delayed_Freeze (E, False);
Set_Freeze_Node (E, Empty);
end if;
end if;
end;
Check_Debug_Info_Needed (E);
end if;
-- AI-117 requires that the convention of a partial view
-- be the same as the convention of the full view. Note
-- that this is a recognized breach of privacy, but it's
-- essential for logical consistency of representation,
-- and the lack of a rule in RM95 was an oversight.
Set_Convention (E, Convention (Full_View (E)));
Set_Size_Known_At_Compile_Time (E,
Size_Known_At_Compile_Time (Full_View (E)));
-- Size information is copied from the full view to the
-- incomplete or private view for consistency
-- We skip this is the full view is not a type. This is
-- very strange of course, and can only happen as a result
-- of certain illegalities, such as a premature attempt to
-- derive from an incomplete type.
if Is_Type (Full_View (E)) then
Set_Size_Info (E, Full_View (E));
Set_RM_Size (E, RM_Size (Full_View (E)));
end if;
return Result;
-- Case of no full view present. If entity is derived or subtype,
-- it is safe to freeze, correctness depends on the frozen status
-- of parent. Otherwise it is either premature usage, or a Taft
-- amendment type, so diagnosis is at the point of use and the
-- type might be frozen later.
elsif E /= Base_Type (E)
or else Is_Derived_Type (E)
then
null;
else
Set_Is_Frozen (E, False);
return No_List;
end if;
-- For access subprogram, freeze types of all formals, the return
-- type was already frozen, since it is the Etype of the function.
elsif Ekind (E) = E_Subprogram_Type then
Formal := First_Formal (E);
while Present (Formal) loop
Freeze_And_Append (Etype (Formal), Loc, Result);
Next_Formal (Formal);
end loop;
-- If the return type requires a transient scope, and we are on
-- a target allowing functions to return with a depressed stack
-- pointer, then we mark the function as requiring this treatment.
if Functions_Return_By_DSP_On_Target
and then Requires_Transient_Scope (Etype (E))
then
Set_Function_Returns_With_DSP (E);
end if;
Freeze_Subprogram (E);
-- For access to a protected subprogram, freeze the equivalent
-- type (however this is not set if we are not generating code)
-- or if this is an anonymous type used just for resolution).
elsif Ekind (E) = E_Access_Protected_Subprogram_Type
and then Operating_Mode = Generate_Code
and then Present (Equivalent_Type (E))
then
Freeze_And_Append (Equivalent_Type (E), Loc, Result);
end if;
-- Generic types are never seen by the back-end, and are also not
-- processed by the expander (since the expander is turned off for
-- generic processing), so we never need freeze nodes for them.
if Is_Generic_Type (E) then
return Result;
end if;
-- Some special processing for non-generic types to complete
-- representation details not known till the freeze point.
if Is_Fixed_Point_Type (E) then
Freeze_Fixed_Point_Type (E);
-- Some error checks required for ordinary fixed-point type.
-- Defer these till the freeze-point since we need the small
-- and range values. We only do these checks for base types
if Is_Ordinary_Fixed_Point_Type (E)
and then E = Base_Type (E)
then
if Small_Value (E) < Ureal_2_M_80 then
Error_Msg_Name_1 := Name_Small;
Error_Msg_N
("`&''%` is too small, minimum is 2.0'*'*(-80)", E);
elsif Small_Value (E) > Ureal_2_80 then
Error_Msg_Name_1 := Name_Small;
Error_Msg_N
("`&''%` is too large, maximum is 2.0'*'*80", E);
end if;
if Expr_Value_R (Type_Low_Bound (E)) < Ureal_M_10_36 then
Error_Msg_Name_1 := Name_First;
Error_Msg_N
("`&''%` is too small, minimum is -10.0'*'*36", E);
end if;
if Expr_Value_R (Type_High_Bound (E)) > Ureal_10_36 then
Error_Msg_Name_1 := Name_Last;
Error_Msg_N
("`&''%` is too large, maximum is 10.0'*'*36", E);
end if;
end if;
elsif Is_Enumeration_Type (E) then
Freeze_Enumeration_Type (E);
elsif Is_Integer_Type (E) then
Adjust_Esize_For_Alignment (E);
elsif Is_Access_Type (E)
and then No (Associated_Storage_Pool (E))
then
Check_Restriction (No_Standard_Storage_Pools, E);
end if;
-- If the current entity is an array or record subtype and has
-- discriminants used to constrain it, it must not freeze, because
-- Freeze_Entity nodes force Gigi to process the frozen type.
if Is_Composite_Type (E) then
if Is_Array_Type (E) then
declare
Index : Node_Id := First_Index (E);
Expr1 : Node_Id;
Expr2 : Node_Id;
begin
while Present (Index) loop
if Etype (Index) /= Any_Type then
Get_Index_Bounds (Index, Expr1, Expr2);
for J in 1 .. 2 loop
if Nkind (Expr1) = N_Identifier
and then Ekind (Entity (Expr1)) = E_Discriminant
then
Set_Has_Delayed_Freeze (E, False);
Set_Freeze_Node (E, Empty);
Check_Debug_Info_Needed (E);
return Result;
end if;
Expr1 := Expr2;
end loop;
end if;
Next_Index (Index);
end loop;
end;
elsif Has_Discriminants (E)
and Is_Constrained (E)
then
declare
Constraint : Elmt_Id;
Expr : Node_Id;
begin
Constraint := First_Elmt (Discriminant_Constraint (E));
while Present (Constraint) loop
Expr := Node (Constraint);
if Nkind (Expr) = N_Identifier
and then Ekind (Entity (Expr)) = E_Discriminant
then
Set_Has_Delayed_Freeze (E, False);
Set_Freeze_Node (E, Empty);
Check_Debug_Info_Needed (E);
return Result;
end if;
Next_Elmt (Constraint);
end loop;
end;
end if;
-- AI-117 requires that all new primitives of a tagged type
-- must inherit the convention of the full view of the type.
-- Inherited and overriding operations are defined to inherit
-- the convention of their parent or overridden subprogram
-- (also specified in AI-117), and that will have occurred
-- earlier (in Derive_Subprogram and New_Overloaded_Entity).
-- Here we set the convention of primitives that are still
-- convention Ada, which will ensure that any new primitives
-- inherit the type's convention. Class-wide types can have
-- a foreign convention inherited from their specific type,
-- but are excluded from this since they don't have any
-- associated primitives.
if Is_Tagged_Type (E)
and then not Is_Class_Wide_Type (E)
and then Convention (E) /= Convention_Ada
then
declare
Prim_List : constant Elist_Id := Primitive_Operations (E);
Prim : Elmt_Id;
begin
Prim := First_Elmt (Prim_List);
while Present (Prim) loop
if Convention (Node (Prim)) = Convention_Ada then
Set_Convention (Node (Prim), Convention (E));
end if;
Next_Elmt (Prim);
end loop;
end;
end if;
end if;
-- Generate primitive operation references for a tagged type
if Is_Tagged_Type (E)
and then not Is_Class_Wide_Type (E)
then
declare
Prim_List : constant Elist_Id := Primitive_Operations (E);
Prim : Elmt_Id;
Ent : Entity_Id;
begin
Prim := First_Elmt (Prim_List);
while Present (Prim) loop
Ent := Node (Prim);
-- If the operation is derived, get the original for
-- cross-reference purposes (it is the original for
-- which we want the xref, and for which the comes
-- from source test needs to be performed).
while Present (Alias (Ent)) loop
Ent := Alias (Ent);
end loop;
Generate_Reference (E, Ent, 'p', Set_Ref => False);
Next_Elmt (Prim);
end loop;
-- If we get an exception, then something peculiar has happened
-- probably as a result of a previous error. Since this is only
-- for non-critical cross-references, ignore the error.
exception
when others => null;
end;
end if;
-- Now that all types from which E may depend are frozen, see
-- if the size is known at compile time, if it must be unsigned,
-- or if strict alignent is required
Check_Compile_Time_Size (E);
Check_Unsigned_Type (E);
if Base_Type (E) = E then
Check_Strict_Alignment (E);
end if;
-- Do not allow a size clause for a type which does not have a size
-- that is known at compile time
if Has_Size_Clause (E)
and then not Size_Known_At_Compile_Time (E)
then
-- Supress this message if errors posted on E, even if we are
-- in all errors mode, since this is often a junk message
if not Error_Posted (E) then
Error_Msg_N
("size clause not allowed for variable length type",
Size_Clause (E));
end if;
end if;
-- Remaining process is to set/verify the representation information,
-- in particular the size and alignment values. This processing is
-- not required for generic types, since generic types do not play
-- any part in code generation, and so the size and alignment values
-- for suhc types are irrelevant.
if Is_Generic_Type (E) then
return Result;
-- Otherwise we call the layout procedure
else
Layout_Type (E);
end if;
-- End of freeze processing for type entities
end if;
-- Here is where we logically freeze the current entity. If it has a
-- freeze node, then this is the point at which the freeze node is
-- linked into the result list.
if Has_Delayed_Freeze (E) then
-- If a freeze node is already allocated, use it, otherwise allocate
-- a new one. The preallocation happens in the case of anonymous base
-- types, where we preallocate so that we can set First_Subtype_Link.
-- Note that we reset the Sloc to the current freeze location.
if Present (Freeze_Node (E)) then
F_Node := Freeze_Node (E);
Set_Sloc (F_Node, Loc);
else
F_Node := New_Node (N_Freeze_Entity, Loc);
Set_Freeze_Node (E, F_Node);
Set_Access_Types_To_Process (F_Node, No_Elist);
Set_TSS_Elist (F_Node, No_Elist);
Set_Actions (F_Node, No_List);
end if;
Set_Entity (F_Node, E);
if Result = No_List then
Result := New_List (F_Node);
else
Append (F_Node, Result);
end if;
end if;
-- When a type is frozen, the first subtype of the type is frozen as
-- well (RM 13.14(15)). This has to be done after freezing the type,
-- since obviously the first subtype depends on its own base type.
if Is_Type (E) then
Freeze_And_Append (First_Subtype (E), Loc, Result);
-- If we just froze a tagged non-class wide record, then freeze the
-- corresponding class-wide type. This must be done after the tagged
-- type itself is frozen, because the class-wide type refers to the
-- tagged type which generates the class.
if Is_Tagged_Type (E)
and then not Is_Class_Wide_Type (E)
and then Present (Class_Wide_Type (E))
then
Freeze_And_Append (Class_Wide_Type (E), Loc, Result);
end if;
end if;
Check_Debug_Info_Needed (E);
-- Special handling for subprograms
if Is_Subprogram (E) then
-- If subprogram has address clause then reset Is_Public flag, since
-- we do not want the backend to generate external references.
if Present (Address_Clause (E))
and then not Is_Library_Level_Entity (E)
then
Set_Is_Public (E, False);
-- If no address clause and not intrinsic, then for imported
-- subprogram in main unit, generate descriptor if we are in
-- Propagate_Exceptions mode.
elsif Propagate_Exceptions
and then Is_Imported (E)
and then not Is_Intrinsic_Subprogram (E)
and then Convention (E) /= Convention_Stubbed
then
if Result = No_List then
Result := Empty_List;
end if;
Generate_Subprogram_Descriptor_For_Imported_Subprogram
(E, Result);
end if;
end if;
return Result;
end Freeze_Entity;
-----------------------------
-- Freeze_Enumeration_Type --
-----------------------------
procedure Freeze_Enumeration_Type (Typ : Entity_Id) is
begin
if Has_Foreign_Convention (Typ)
and then not Has_Size_Clause (Typ)
and then Esize (Typ) < Standard_Integer_Size
then
Init_Esize (Typ, Standard_Integer_Size);
else
Adjust_Esize_For_Alignment (Typ);
end if;
end Freeze_Enumeration_Type;
-----------------------
-- Freeze_Expression --
-----------------------
procedure Freeze_Expression (N : Node_Id) is
In_Def_Exp : constant Boolean := In_Default_Expression;
Typ : Entity_Id;
Nam : Entity_Id;
Desig_Typ : Entity_Id;
P : Node_Id;
Parent_P : Node_Id;
Freeze_Outside : Boolean := False;
-- This flag is set true if the entity must be frozen outside the
-- current subprogram. This happens in the case of expander generated
-- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
-- not freeze all entities like other bodies, but which nevertheless
-- may reference entities that have to be frozen before the body and
-- obviously cannot be frozen inside the body.
function In_Exp_Body (N : Node_Id) return Boolean;
-- Given an N_Handled_Sequence_Of_Statements node N, determines whether
-- it is the handled statement sequence of an expander generated
-- subprogram (init proc, or stream subprogram). If so, it returns
-- True, otherwise False.
-----------------
-- In_Exp_Body --
-----------------
function In_Exp_Body (N : Node_Id) return Boolean is
P : Node_Id;
begin
if Nkind (N) = N_Subprogram_Body then
P := N;
else
P := Parent (N);
end if;
if Nkind (P) /= N_Subprogram_Body then
return False;
else
P := Defining_Unit_Name (Specification (P));
if Nkind (P) = N_Defining_Identifier
and then (Is_Init_Proc (P) or else
Is_TSS (P, TSS_Stream_Input) or else
Is_TSS (P, TSS_Stream_Output) or else
Is_TSS (P, TSS_Stream_Read) or else
Is_TSS (P, TSS_Stream_Write))
then
return True;
else
return False;
end if;
end if;
end In_Exp_Body;
-- Start of processing for Freeze_Expression
begin
-- Immediate return if freezing is inhibited. This flag is set by
-- the analyzer to stop freezing on generated expressions that would
-- cause freezing if they were in the source program, but which are
-- not supposed to freeze, since they are created.
if Must_Not_Freeze (N) then
return;
end if;
-- If expression is non-static, then it does not freeze in a default
-- expression, see section "Handling of Default Expressions" in the
-- spec of package Sem for further details. Note that we have to
-- make sure that we actually have a real expression (if we have
-- a subtype indication, we can't test Is_Static_Expression!)
if In_Def_Exp
and then Nkind (N) in N_Subexpr
and then not Is_Static_Expression (N)
then
return;
end if;
-- Freeze type of expression if not frozen already
Typ := Empty;
if Nkind (N) in N_Has_Etype then
if not Is_Frozen (Etype (N)) then
Typ := Etype (N);
-- Base type may be an derived numeric type that is frozen at
-- the point of declaration, but first_subtype is still unfrozen.
elsif not Is_Frozen (First_Subtype (Etype (N))) then
Typ := First_Subtype (Etype (N));
end if;
end if;
-- For entity name, freeze entity if not frozen already. A special
-- exception occurs for an identifier that did not come from source.
-- We don't let such identifiers freeze a non-internal entity, i.e.
-- an entity that did come from source, since such an identifier was
-- generated by the expander, and cannot have any semantic effect on
-- the freezing semantics. For example, this stops the parameter of
-- an initialization procedure from freezing the variable.
if Is_Entity_Name (N)
and then not Is_Frozen (Entity (N))
and then (Nkind (N) /= N_Identifier
or else Comes_From_Source (N)
or else not Comes_From_Source (Entity (N)))
then
Nam := Entity (N);
else
Nam := Empty;
end if;
-- For an allocator freeze designated type if not frozen already.
-- For an aggregate whose component type is an access type, freeze
-- the designated type now, so that its freeze does not appear within
-- the loop that might be created in the expansion of the aggregate.
-- If the designated type is a private type without full view, the
-- expression cannot contain an allocator, so the type is not frozen.
Desig_Typ := Empty;
case Nkind (N) is
when N_Allocator =>
Desig_Typ := Designated_Type (Etype (N));
when N_Aggregate =>
if Is_Array_Type (Etype (N))
and then Is_Access_Type (Component_Type (Etype (N)))
then
Desig_Typ := Designated_Type (Component_Type (Etype (N)));
end if;
when N_Selected_Component |
N_Indexed_Component |
N_Slice =>
if Is_Access_Type (Etype (Prefix (N))) then
Desig_Typ := Designated_Type (Etype (Prefix (N)));
end if;
when others =>
null;
end case;
if Desig_Typ /= Empty
and then (Is_Frozen (Desig_Typ)
or else (not Is_Fully_Defined (Desig_Typ)))
then
Desig_Typ := Empty;
end if;
-- All done if nothing needs freezing
if No (Typ)
and then No (Nam)
and then No (Desig_Typ)
then
return;
end if;
-- Loop for looking at the right place to insert the freeze nodes
-- exiting from the loop when it is appropriate to insert the freeze
-- node before the current node P.
-- Also checks some special exceptions to the freezing rules. These
-- cases result in a direct return, bypassing the freeze action.
P := N;
loop
Parent_P := Parent (P);
-- If we don't have a parent, then we are not in a well-formed
-- tree. This is an unusual case, but there are some legitimate
-- situations in which this occurs, notably when the expressions
-- in the range of a type declaration are resolved. We simply
-- ignore the freeze request in this case. Is this right ???
if No (Parent_P) then
return;
end if;
-- See if we have got to an appropriate point in the tree
case Nkind (Parent_P) is
-- A special test for the exception of (RM 13.14(8)) for the
-- case of per-object expressions (RM 3.8(18)) occurring in a
-- component definition or a discrete subtype definition. Note
-- that we test for a component declaration which includes both
-- cases we are interested in, and furthermore the tree does not
-- have explicit nodes for either of these two constructs.
when N_Component_Declaration =>
-- The case we want to test for here is an identifier that is
-- a per-object expression, this is either a discriminant that
-- appears in a context other than the component declaration
-- or it is a reference to the type of the enclosing construct.
-- For either of these cases, we skip the freezing
if not In_Default_Expression
and then Nkind (N) = N_Identifier
and then (Present (Entity (N)))
then
-- We recognize the discriminant case by just looking for
-- a reference to a discriminant. It can only be one for
-- the enclosing construct. Skip freezing in this case.
if Ekind (Entity (N)) = E_Discriminant then
return;
-- For the case of a reference to the enclosing record,
-- (or task or protected type), we look for a type that
-- matches the current scope.
elsif Entity (N) = Current_Scope then
return;
end if;
end if;
-- If we have an enumeration literal that appears as the
-- choice in the aggregate of an enumeration representation
-- clause, then freezing does not occur (RM 13.14(10)).
when N_Enumeration_Representation_Clause =>
-- The case we are looking for is an enumeration literal
if (Nkind (N) = N_Identifier or Nkind (N) = N_Character_Literal)
and then Is_Enumeration_Type (Etype (N))
then
-- If enumeration literal appears directly as the choice,
-- do not freeze (this is the normal non-overloade case)
if Nkind (Parent (N)) = N_Component_Association
and then First (Choices (Parent (N))) = N
then
return;
-- If enumeration literal appears as the name of a
-- function which is the choice, then also do not freeze.
-- This happens in the overloaded literal case, where the
-- enumeration literal is temporarily changed to a function
-- call for overloading analysis purposes.
elsif Nkind (Parent (N)) = N_Function_Call
and then
Nkind (Parent (Parent (N))) = N_Component_Association
and then
First (Choices (Parent (Parent (N)))) = Parent (N)
then
return;
end if;
end if;
-- Normally if the parent is a handled sequence of statements,
-- then the current node must be a statement, and that is an
-- appropriate place to insert a freeze node.
when N_Handled_Sequence_Of_Statements =>
-- An exception occurs when the sequence of statements is
-- for an expander generated body that did not do the usual
-- freeze all operation. In this case we usually want to
-- freeze outside this body, not inside it, and we skip
-- past the subprogram body that we are inside.
if In_Exp_Body (Parent_P) then
-- However, we *do* want to freeze at this point if we have
-- an entity to freeze, and that entity is declared *inside*
-- the body of the expander generated procedure. This case
-- is recognized by the scope of the type, which is either
-- the spec for some enclosing body, or (in the case of
-- init_procs, for which there are no separate specs) the
-- current scope.
declare
Subp : constant Node_Id := Parent (Parent_P);
Cspc : Entity_Id;
begin
if Nkind (Subp) = N_Subprogram_Body then
Cspc := Corresponding_Spec (Subp);
if (Present (Typ) and then Scope (Typ) = Cspc)
or else
(Present (Nam) and then Scope (Nam) = Cspc)
then
exit;
elsif Present (Typ)
and then Scope (Typ) = Current_Scope
and then Current_Scope = Defining_Entity (Subp)
then
exit;
end if;
end if;
end;
-- If not that exception to the exception, then this is
-- where we delay the freeze till outside the body.
Parent_P := Parent (Parent_P);
Freeze_Outside := True;
-- Here if normal case where we are in handled statement
-- sequence and want to do the insertion right there.
else
exit;
end if;
-- If parent is a body or a spec or a block, then the current
-- node is a statement or declaration and we can insert the
-- freeze node before it.
when N_Package_Specification |
N_Package_Body |
N_Subprogram_Body |
N_Task_Body |
N_Protected_Body |
N_Entry_Body |
N_Block_Statement => exit;
-- The expander is allowed to define types in any statements list,
-- so any of the following parent nodes also mark a freezing point
-- if the actual node is in a list of statements or declarations.
when N_Exception_Handler |
N_If_Statement |
N_Elsif_Part |
N_Case_Statement_Alternative |
N_Compilation_Unit_Aux |
N_Selective_Accept |
N_Accept_Alternative |
N_Delay_Alternative |
N_Conditional_Entry_Call |
N_Entry_Call_Alternative |
N_Triggering_Alternative |
N_Abortable_Part |
N_Freeze_Entity =>
exit when Is_List_Member (P);
-- Note: The N_Loop_Statement is a special case. A type that
-- appears in the source can never be frozen in a loop (this
-- occurs only because of a loop expanded by the expander),
-- so we keep on going. Otherwise we terminate the search.
-- Same is true of any entity which comes from source. (if they
-- have a predefined type, that type does not appear to come
-- from source, but the entity should not be frozen here).
when N_Loop_Statement =>
exit when not Comes_From_Source (Etype (N))
and then (No (Nam) or else not Comes_From_Source (Nam));
-- For all other cases, keep looking at parents
when others =>
null;
end case;
-- We fall through the case if we did not yet find the proper
-- place in the free for inserting the freeze node, so climb!
P := Parent_P;
end loop;
-- If the expression appears in a record or an initialization
-- procedure, the freeze nodes are collected and attached to
-- the current scope, to be inserted and analyzed on exit from
-- the scope, to insure that generated entities appear in the
-- correct scope. If the expression is a default for a discriminant
-- specification, the scope is still void. The expression can also
-- appear in the discriminant part of a private or concurrent type.
-- The other case requiring this special handling is if we are in
-- a default expression, since in that case we are about to freeze
-- a static type, and the freeze scope needs to be the outer scope,
-- not the scope of the subprogram with the default parameter.
-- For default expressions in generic units, the Move_Freeze_Nodes
-- mechanism (see sem_ch12.adb) takes care of placing them at the
-- proper place, after the generic unit.
if (In_Def_Exp and not Inside_A_Generic)
or else Freeze_Outside
or else (Is_Type (Current_Scope)
and then (not Is_Concurrent_Type (Current_Scope)
or else not Has_Completion (Current_Scope)))
or else Ekind (Current_Scope) = E_Void
then
declare
Loc : constant Source_Ptr := Sloc (Current_Scope);
Freeze_Nodes : List_Id := No_List;
begin
if Present (Desig_Typ) then
Freeze_And_Append (Desig_Typ, Loc, Freeze_Nodes);
end if;
if Present (Typ) then
Freeze_And_Append (Typ, Loc, Freeze_Nodes);
end if;
if Present (Nam) then
Freeze_And_Append (Nam, Loc, Freeze_Nodes);
end if;
if Is_Non_Empty_List (Freeze_Nodes) then
if No (Scope_Stack.Table
(Scope_Stack.Last).Pending_Freeze_Actions)
then
Scope_Stack.Table
(Scope_Stack.Last).Pending_Freeze_Actions :=
Freeze_Nodes;
else
Append_List (Freeze_Nodes, Scope_Stack.Table
(Scope_Stack.Last).Pending_Freeze_Actions);
end if;
end if;
end;
return;
end if;
-- Now we have the right place to do the freezing. First, a special
-- adjustment, if we are in default expression analysis mode, these
-- freeze actions must not be thrown away (normally all inserted
-- actions are thrown away in this mode. However, the freeze actions
-- are from static expressions and one of the important reasons we
-- are doing this special analysis is to get these freeze actions.
-- Therefore we turn off the In_Default_Expression mode to propagate
-- these freeze actions. This also means they get properly analyzed
-- and expanded.
In_Default_Expression := False;
-- Freeze the designated type of an allocator (RM 13.14(13))
if Present (Desig_Typ) then
Freeze_Before (P, Desig_Typ);
end if;
-- Freeze type of expression (RM 13.14(10)). Note that we took care of
-- the enumeration representation clause exception in the loop above.
if Present (Typ) then
Freeze_Before (P, Typ);
end if;
-- Freeze name if one is present (RM 13.14(11))
if Present (Nam) then
Freeze_Before (P, Nam);
end if;
In_Default_Expression := In_Def_Exp;
end Freeze_Expression;
-----------------------------
-- Freeze_Fixed_Point_Type --
-----------------------------
-- Certain fixed-point types and subtypes, including implicit base
-- types and declared first subtypes, have not yet set up a range.
-- This is because the range cannot be set until the Small and Size
-- values are known, and these are not known till the type is frozen.
-- To signal this case, Scalar_Range contains an unanalyzed syntactic
-- range whose bounds are unanalyzed real literals. This routine will
-- recognize this case, and transform this range node into a properly
-- typed range with properly analyzed and resolved values.
procedure Freeze_Fixed_Point_Type (Typ : Entity_Id) is
Rng : constant Node_Id := Scalar_Range (Typ);
Lo : constant Node_Id := Low_Bound (Rng);
Hi : constant Node_Id := High_Bound (Rng);
Btyp : constant Entity_Id := Base_Type (Typ);
Brng : constant Node_Id := Scalar_Range (Btyp);
BLo : constant Node_Id := Low_Bound (Brng);
BHi : constant Node_Id := High_Bound (Brng);
Small : constant Ureal := Small_Value (Typ);
Loval : Ureal;
Hival : Ureal;
Atype : Entity_Id;
Actual_Size : Nat;
function Fsize (Lov, Hiv : Ureal) return Nat;
-- Returns size of type with given bounds. Also leaves these
-- bounds set as the current bounds of the Typ.
function Fsize (Lov, Hiv : Ureal) return Nat is
begin
Set_Realval (Lo, Lov);
Set_Realval (Hi, Hiv);
return Minimum_Size (Typ);
end Fsize;
-- Start of processing for Freeze_Fixed_Point_Type;
begin
-- If Esize of a subtype has not previously been set, set it now
if Unknown_Esize (Typ) then
Atype := Ancestor_Subtype (Typ);
if Present (Atype) then
Set_Esize (Typ, Esize (Atype));
else
Set_Esize (Typ, Esize (Base_Type (Typ)));
end if;
end if;
-- Immediate return if the range is already analyzed. This means
-- that the range is already set, and does not need to be computed
-- by this routine.
if Analyzed (Rng) then
return;
end if;
-- Immediate return if either of the bounds raises Constraint_Error
if Raises_Constraint_Error (Lo)
or else Raises_Constraint_Error (Hi)
then
return;
end if;
Loval := Realval (Lo);
Hival := Realval (Hi);
-- Ordinary fixed-point case
if Is_Ordinary_Fixed_Point_Type (Typ) then
-- For the ordinary fixed-point case, we are allowed to fudge the
-- end-points up or down by small. Generally we prefer to fudge
-- up, i.e. widen the bounds for non-model numbers so that the
-- end points are included. However there are cases in which this
-- cannot be done, and indeed cases in which we may need to narrow
-- the bounds. The following circuit makes the decision.
-- Note: our terminology here is that Incl_EP means that the
-- bounds are widened by Small if necessary to include the end
-- points, and Excl_EP means that the bounds are narrowed by
-- Small to exclude the end-points if this reduces the size.
-- Note that in the Incl case, all we care about is including the
-- end-points. In the Excl case, we want to narrow the bounds as
-- much as permitted by the RM, to give the smallest possible size.
Fudge : declare
Loval_Incl_EP : Ureal;
Hival_Incl_EP : Ureal;
Loval_Excl_EP : Ureal;
Hival_Excl_EP : Ureal;
Size_Incl_EP : Nat;
Size_Excl_EP : Nat;
Model_Num : Ureal;
First_Subt : Entity_Id;
Actual_Lo : Ureal;
Actual_Hi : Ureal;
begin
-- First step. Base types are required to be symmetrical. Right
-- now, the base type range is a copy of the first subtype range.
-- This will be corrected before we are done, but right away we
-- need to deal with the case where both bounds are non-negative.
-- In this case, we set the low bound to the negative of the high
-- bound, to make sure that the size is computed to include the
-- required sign. Note that we do not need to worry about the
-- case of both bounds negative, because the sign will be dealt
-- with anyway. Furthermore we can't just go making such a bound
-- symmetrical, since in a twos-complement system, there is an
-- extra negative value which could not be accomodated on the
-- positive side.
if Typ = Btyp
and then not UR_Is_Negative (Loval)
and then Hival > Loval
then
Loval := -Hival;
Set_Realval (Lo, Loval);
end if;
-- Compute the fudged bounds. If the number is a model number,
-- then we do nothing to include it, but we are allowed to
-- backoff to the next adjacent model number when we exclude
-- it. If it is not a model number then we straddle the two
-- values with the model numbers on either side.
Model_Num := UR_Trunc (Loval / Small) * Small;
if Loval = Model_Num then
Loval_Incl_EP := Model_Num;
else
Loval_Incl_EP := Model_Num - Small;
end if;
-- The low value excluding the end point is Small greater, but
-- we do not do this exclusion if the low value is positive,
-- since it can't help the size and could actually hurt by
-- crossing the high bound.
if UR_Is_Negative (Loval_Incl_EP) then
Loval_Excl_EP := Loval_Incl_EP + Small;
else
Loval_Excl_EP := Loval_Incl_EP;
end if;
-- Similar processing for upper bound and high value
Model_Num := UR_Trunc (Hival / Small) * Small;
if Hival = Model_Num then
Hival_Incl_EP := Model_Num;
else
Hival_Incl_EP := Model_Num + Small;
end if;
if UR_Is_Positive (Hival_Incl_EP) then
Hival_Excl_EP := Hival_Incl_EP - Small;
else
Hival_Excl_EP := Hival_Incl_EP;
end if;
-- One further adjustment is needed. In the case of subtypes,
-- we cannot go outside the range of the base type, or we get
-- peculiarities, and the base type range is already set. This
-- only applies to the Incl values, since clearly the Excl
-- values are already as restricted as they are allowed to be.
if Typ /= Btyp then
Loval_Incl_EP := UR_Max (Loval_Incl_EP, Realval (BLo));
Hival_Incl_EP := UR_Min (Hival_Incl_EP, Realval (BHi));
end if;
-- Get size including and excluding end points
Size_Incl_EP := Fsize (Loval_Incl_EP, Hival_Incl_EP);
Size_Excl_EP := Fsize (Loval_Excl_EP, Hival_Excl_EP);
-- No need to exclude end-points if it does not reduce size
if Fsize (Loval_Incl_EP, Hival_Excl_EP) = Size_Excl_EP then
Loval_Excl_EP := Loval_Incl_EP;
end if;
if Fsize (Loval_Excl_EP, Hival_Incl_EP) = Size_Excl_EP then
Hival_Excl_EP := Hival_Incl_EP;
end if;
-- Now we set the actual size to be used. We want to use the
-- bounds fudged up to include the end-points but only if this
-- can be done without violating a specifically given size
-- size clause or causing an unacceptable increase in size.
-- Case of size clause given
if Has_Size_Clause (Typ) then
-- Use the inclusive size only if it is consistent with
-- the explicitly specified size.
if Size_Incl_EP <= RM_Size (Typ) then
Actual_Lo := Loval_Incl_EP;
Actual_Hi := Hival_Incl_EP;
Actual_Size := Size_Incl_EP;
-- If the inclusive size is too large, we try excluding
-- the end-points (will be caught later if does not work).
else
Actual_Lo := Loval_Excl_EP;
Actual_Hi := Hival_Excl_EP;
Actual_Size := Size_Excl_EP;
end if;
-- Case of size clause not given
else
-- If we have a base type whose corresponding first subtype
-- has an explicit size that is large enough to include our
-- end-points, then do so. There is no point in working hard
-- to get a base type whose size is smaller than the specified
-- size of the first subtype.
First_Subt := First_Subtype (Typ);
if Has_Size_Clause (First_Subt)
and then Size_Incl_EP <= Esize (First_Subt)
then
Actual_Size := Size_Incl_EP;
Actual_Lo := Loval_Incl_EP;
Actual_Hi := Hival_Incl_EP;
-- If excluding the end-points makes the size smaller and
-- results in a size of 8,16,32,64, then we take the smaller
-- size. For the 64 case, this is compulsory. For the other
-- cases, it seems reasonable. We like to include end points
-- if we can, but not at the expense of moving to the next
-- natural boundary of size.
elsif Size_Incl_EP /= Size_Excl_EP
and then
(Size_Excl_EP = 8 or else
Size_Excl_EP = 16 or else
Size_Excl_EP = 32 or else
Size_Excl_EP = 64)
then
Actual_Size := Size_Excl_EP;
Actual_Lo := Loval_Excl_EP;
Actual_Hi := Hival_Excl_EP;
-- Otherwise we can definitely include the end points
else
Actual_Size := Size_Incl_EP;
Actual_Lo := Loval_Incl_EP;
Actual_Hi := Hival_Incl_EP;
end if;
-- One pathological case: normally we never fudge a low
-- bound down, since it would seem to increase the size
-- (if it has any effect), but for ranges containing a
-- single value, or no values, the high bound can be
-- small too large. Consider:
-- type t is delta 2.0**(-14)
-- range 131072.0 .. 0;
-- That lower bound is *just* outside the range of 32
-- bits, and does need fudging down in this case. Note
-- that the bounds will always have crossed here, since
-- the high bound will be fudged down if necessary, as
-- in the case of:
-- type t is delta 2.0**(-14)
-- range 131072.0 .. 131072.0;
-- So we can detect the situation by looking for crossed
-- bounds, and if the bounds are crossed, and the low
-- bound is greater than zero, we will always back it
-- off by small, since this is completely harmless.
if Actual_Lo > Actual_Hi then
if UR_Is_Positive (Actual_Lo) then
Actual_Lo := Loval_Incl_EP - Small;
Actual_Size := Fsize (Actual_Lo, Actual_Hi);
-- And of course, we need to do exactly the same parallel
-- fudge for flat ranges in the negative region.
elsif UR_Is_Negative (Actual_Hi) then
Actual_Hi := Hival_Incl_EP + Small;
Actual_Size := Fsize (Actual_Lo, Actual_Hi);
end if;
end if;
end if;
Set_Realval (Lo, Actual_Lo);
Set_Realval (Hi, Actual_Hi);
end Fudge;
-- For the decimal case, none of this fudging is required, since there
-- are no end-point problems in the decimal case (the end-points are
-- always included).
else
Actual_Size := Fsize (Loval, Hival);
end if;
-- At this stage, the actual size has been calculated and the proper
-- required bounds are stored in the low and high bounds.
if Actual_Size > 64 then
Error_Msg_Uint_1 := UI_From_Int (Actual_Size);
Error_Msg_N
("size required (^) for type& too large, maximum is 64", Typ);
Actual_Size := 64;
end if;
-- Check size against explicit given size
if Has_Size_Clause (Typ) then
if Actual_Size > RM_Size (Typ) then
Error_Msg_Uint_1 := RM_Size (Typ);
Error_Msg_Uint_2 := UI_From_Int (Actual_Size);
Error_Msg_NE
("size given (^) for type& too small, minimum is ^",
Size_Clause (Typ), Typ);
else
Actual_Size := UI_To_Int (Esize (Typ));
end if;
-- Increase size to next natural boundary if no size clause given
else
if Actual_Size <= 8 then
Actual_Size := 8;
elsif Actual_Size <= 16 then
Actual_Size := 16;
elsif Actual_Size <= 32 then
Actual_Size := 32;
else
Actual_Size := 64;
end if;
Init_Esize (Typ, Actual_Size);
Adjust_Esize_For_Alignment (Typ);
end if;
-- If we have a base type, then expand the bounds so that they
-- extend to the full width of the allocated size in bits, to
-- avoid junk range checks on intermediate computations.
if Base_Type (Typ) = Typ then
Set_Realval (Lo, -(Small * (Uint_2 ** (Actual_Size - 1))));
Set_Realval (Hi, (Small * (Uint_2 ** (Actual_Size - 1) - 1)));
end if;
-- Final step is to reanalyze the bounds using the proper type
-- and set the Corresponding_Integer_Value fields of the literals.
Set_Etype (Lo, Empty);
Set_Analyzed (Lo, False);
Analyze (Lo);
-- Resolve with universal fixed if the base type, and the base
-- type if it is a subtype. Note we can't resolve the base type
-- with itself, that would be a reference before definition.
if Typ = Btyp then
Resolve (Lo, Universal_Fixed);
else
Resolve (Lo, Btyp);
end if;
-- Set corresponding integer value for bound
Set_Corresponding_Integer_Value
(Lo, UR_To_Uint (Realval (Lo) / Small));
-- Similar processing for high bound
Set_Etype (Hi, Empty);
Set_Analyzed (Hi, False);
Analyze (Hi);
if Typ = Btyp then
Resolve (Hi, Universal_Fixed);
else
Resolve (Hi, Btyp);
end if;
Set_Corresponding_Integer_Value
(Hi, UR_To_Uint (Realval (Hi) / Small));
-- Set type of range to correspond to bounds
Set_Etype (Rng, Etype (Lo));
-- Set Esize to calculated size if not set already
if Unknown_Esize (Typ) then
Init_Esize (Typ, Actual_Size);
end if;
-- Set RM_Size if not already set. If already set, check value
declare
Minsiz : constant Uint := UI_From_Int (Minimum_Size (Typ));
begin
if RM_Size (Typ) /= Uint_0 then
if RM_Size (Typ) < Minsiz then
Error_Msg_Uint_1 := RM_Size (Typ);
Error_Msg_Uint_2 := Minsiz;
Error_Msg_NE
("size given (^) for type& too small, minimum is ^",
Size_Clause (Typ), Typ);
end if;
else
Set_RM_Size (Typ, Minsiz);
end if;
end;
end Freeze_Fixed_Point_Type;
------------------
-- Freeze_Itype --
------------------
procedure Freeze_Itype (T : Entity_Id; N : Node_Id) is
L : List_Id;
begin
Set_Has_Delayed_Freeze (T);
L := Freeze_Entity (T, Sloc (N));
if Is_Non_Empty_List (L) then
Insert_Actions (N, L);
end if;
end Freeze_Itype;
--------------------------
-- Freeze_Static_Object --
--------------------------
procedure Freeze_Static_Object (E : Entity_Id) is
Cannot_Be_Static : exception;
-- Exception raised if the type of a static object cannot be made
-- static. This happens if the type depends on non-global objects.
procedure Ensure_Expression_Is_SA (N : Node_Id);
-- Called to ensure that an expression used as part of a type
-- definition is statically allocatable, which means that the type
-- of the expression is statically allocatable, and the expression
-- is either static, or a reference to a library level constant.
procedure Ensure_Type_Is_SA (Typ : Entity_Id);
-- Called to mark a type as static, checking that it is possible
-- to set the type as static. If it is not possible, then the
-- exception Cannot_Be_Static is raised.
-----------------------------
-- Ensure_Expression_Is_SA --
-----------------------------
procedure Ensure_Expression_Is_SA (N : Node_Id) is
Ent : Entity_Id;
begin
Ensure_Type_Is_SA (Etype (N));
if Is_Static_Expression (N) then
return;
elsif Nkind (N) = N_Identifier then
Ent := Entity (N);
if Present (Ent)
and then Ekind (Ent) = E_Constant
and then Is_Library_Level_Entity (Ent)
then
return;
end if;
end if;
raise Cannot_Be_Static;
end Ensure_Expression_Is_SA;
-----------------------
-- Ensure_Type_Is_SA --
-----------------------
procedure Ensure_Type_Is_SA (Typ : Entity_Id) is
N : Node_Id;
C : Entity_Id;
begin
-- If type is library level, we are all set
if Is_Library_Level_Entity (Typ) then
return;
end if;
-- We are also OK if the type is already marked as statically
-- allocated, which means we processed it before.
if Is_Statically_Allocated (Typ) then
return;
end if;
-- Mark type as statically allocated
Set_Is_Statically_Allocated (Typ);
-- Check that it is safe to statically allocate this type
if Is_Scalar_Type (Typ) or else Is_Real_Type (Typ) then
Ensure_Expression_Is_SA (Type_Low_Bound (Typ));
Ensure_Expression_Is_SA (Type_High_Bound (Typ));
elsif Is_Array_Type (Typ) then
N := First_Index (Typ);
while Present (N) loop
Ensure_Type_Is_SA (Etype (N));
Next_Index (N);
end loop;
Ensure_Type_Is_SA (Component_Type (Typ));
elsif Is_Access_Type (Typ) then
if Ekind (Designated_Type (Typ)) = E_Subprogram_Type then
declare
F : Entity_Id;
T : constant Entity_Id := Etype (Designated_Type (Typ));
begin
if T /= Standard_Void_Type then
Ensure_Type_Is_SA (T);
end if;
F := First_Formal (Designated_Type (Typ));
while Present (F) loop
Ensure_Type_Is_SA (Etype (F));
Next_Formal (F);
end loop;
end;
else
Ensure_Type_Is_SA (Designated_Type (Typ));
end if;
elsif Is_Record_Type (Typ) then
C := First_Entity (Typ);
while Present (C) loop
if Ekind (C) = E_Discriminant
or else Ekind (C) = E_Component
then
Ensure_Type_Is_SA (Etype (C));
elsif Is_Type (C) then
Ensure_Type_Is_SA (C);
end if;
Next_Entity (C);
end loop;
elsif Ekind (Typ) = E_Subprogram_Type then
Ensure_Type_Is_SA (Etype (Typ));
C := First_Formal (Typ);
while Present (C) loop
Ensure_Type_Is_SA (Etype (C));
Next_Formal (C);
end loop;
else
raise Cannot_Be_Static;
end if;
end Ensure_Type_Is_SA;
-- Start of processing for Freeze_Static_Object
begin
Ensure_Type_Is_SA (Etype (E));
-- Reset True_Constant flag, since something strange is going on
-- with the scoping here, and our simple value traceing may not
-- be sufficient for this indication to be reliable. We kill the
-- Constant_Value indication for the same reason.
Set_Is_True_Constant (E, False);
Set_Current_Value (E, Empty);
exception
when Cannot_Be_Static =>
-- If the object that cannot be static is imported or exported,
-- then we give an error message saying that this object cannot
-- be imported or exported.
if Is_Imported (E) then
Error_Msg_N
("& cannot be imported (local type is not constant)", E);
-- Otherwise must be exported, something is wrong if compiler
-- is marking something as statically allocated which cannot be).
else pragma Assert (Is_Exported (E));
Error_Msg_N
("& cannot be exported (local type is not constant)", E);
end if;
end Freeze_Static_Object;
-----------------------
-- Freeze_Subprogram --
-----------------------
procedure Freeze_Subprogram (E : Entity_Id) is
Retype : Entity_Id;
F : Entity_Id;
begin
-- Subprogram may not have an address clause unless it is imported
if Present (Address_Clause (E)) then
if not Is_Imported (E) then
Error_Msg_N
("address clause can only be given " &
"for imported subprogram",
Name (Address_Clause (E)));
end if;
end if;
-- Reset the Pure indication on an imported subprogram unless an
-- explicit Pure_Function pragma was present. We do this because
-- otherwise it is an insidious error to call a non-pure function
-- from a pure unit and have calls mysteriously optimized away.
-- What happens here is that the Import can bypass the normal
-- check to ensure that pure units call only pure subprograms.
if Is_Imported (E)
and then Is_Pure (E)
and then not Has_Pragma_Pure_Function (E)
then
Set_Is_Pure (E, False);
end if;
-- For non-foreign convention subprograms, this is where we create
-- the extra formals (for accessibility level and constrained bit
-- information). We delay this till the freeze point precisely so
-- that we know the convention!
if not Has_Foreign_Convention (E) then
Create_Extra_Formals (E);
Set_Mechanisms (E);
-- If this is convention Ada and a Valued_Procedure, that's odd
if Ekind (E) = E_Procedure
and then Is_Valued_Procedure (E)
and then Convention (E) = Convention_Ada
and then Warn_On_Export_Import
then
Error_Msg_N
("?Valued_Procedure has no effect for convention Ada", E);
Set_Is_Valued_Procedure (E, False);
end if;
-- Case of foreign convention
else
Set_Mechanisms (E);
-- For foreign conventions, warn about return of an
-- unconstrained array.
-- Note: we *do* allow a return by descriptor for the VMS case,
-- though here there is probably more to be done ???
if Ekind (E) = E_Function then
Retype := Underlying_Type (Etype (E));
-- If no return type, probably some other error, e.g. a
-- missing full declaration, so ignore.
if No (Retype) then
null;
-- If the return type is generic, we have emitted a warning
-- earlier on, and there is nothing else to check here.
-- Specific instantiations may lead to erroneous behavior.
elsif Is_Generic_Type (Etype (E)) then
null;
elsif Is_Array_Type (Retype)
and then not Is_Constrained (Retype)
and then Mechanism (E) not in Descriptor_Codes
and then Warn_On_Export_Import
then
Error_Msg_N
("?foreign convention function& should not return " &
"unconstrained array", E);
return;
end if;
end if;
-- If any of the formals for an exported foreign convention
-- subprogram have defaults, then emit an appropriate warning
-- since this is odd (default cannot be used from non-Ada code)
if Is_Exported (E) then