From b094d6c4bf572654a031ecc4afe675154c886dc5 Mon Sep 17 00:00:00 2001 From: Jing Yu Date: Thu, 22 Jul 2010 14:03:48 -0700 Subject: commit gcc-4.4.3 which is used to build gcc-4.4.3 Android toolchain in master. The source is based on fsf gcc-4.4.3 and contains local patches which are recorded in gcc-4.4.3/README.google. Change-Id: Id8c6d6927df274ae9749196a1cc24dbd9abc9887 --- gcc-4.4.3/gcc/ada/freeze.adb | 5609 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 5609 insertions(+) create mode 100644 gcc-4.4.3/gcc/ada/freeze.adb (limited to 'gcc-4.4.3/gcc/ada/freeze.adb') diff --git a/gcc-4.4.3/gcc/ada/freeze.adb b/gcc-4.4.3/gcc/ada/freeze.adb new file mode 100644 index 000000000..28add0f0a --- /dev/null +++ b/gcc-4.4.3/gcc/ada/freeze.adb @@ -0,0 +1,5609 @@ +----------------------------------------------------------------------------- +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- F R E E Z E -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- You should have received a copy of the GNU General Public License along -- +-- with this program; see file COPYING3. If not see -- +-- . -- +-- -- +-- 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_Ch3; use Exp_Ch3; +with Exp_Ch7; use Exp_Ch7; +with Exp_Disp; use Exp_Disp; +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 Namet; use Namet; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Restrict; use Restrict; +with Rident; use Rident; +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 Generate_Prim_Op_References (Typ : Entity_Id); + -- For a tagged type, generate implicit references to its primitive + -- operations, for source navigation. + + 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. This procedure also ensures that + -- subsidiary entities have the flag set as required. + + procedure Undelay_Type (T : Entity_Id); + -- T is a type of a component that we know to be an Itype. + -- We don't want this to have a Freeze_Node, so ensure it doesn't. + -- Do the same for any Full_View or Corresponding_Record_Type. + + 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; + + Pref : Node_Id := Empty; + -- If the renamed entity is a primitive operation given in prefix form, + -- the prefix is the target object and it has to be added as the first + -- actual in the generated call. + + 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 + if Nkind (Nam) = N_Selected_Component + and then Present (First_Formal (Old_S)) + and then + (Is_Controlling_Formal (First_Formal (Old_S)) + or else Is_Class_Wide_Type (Etype (First_Formal (Old_S)))) + then + + -- Retrieve the target object, to be added as a first actual + -- in the call. + + Call_Name := New_Occurrence_Of (Old_S, Loc); + Pref := Prefix (Nam); + + else + Call_Name := New_Copy (Name (N)); + end if; + + -- 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 (Pref) then + declare + Pref_Type : constant Entity_Id := Etype (Pref); + Form_Type : constant Entity_Id := Etype (First_Formal (Old_S)); + + begin + + -- The controlling formal may be an access parameter, or the + -- actual may be an access value, so adjust accordingly. + + if Is_Access_Type (Pref_Type) + and then not Is_Access_Type (Form_Type) + then + Actuals := New_List + (Make_Explicit_Dereference (Loc, Relocate_Node (Pref))); + + elsif Is_Access_Type (Form_Type) + and then not Is_Access_Type (Pref) + then + Actuals := New_List + (Make_Attribute_Reference (Loc, + Attribute_Name => Name_Access, + Prefix => Relocate_Node (Pref))); + else + Actuals := New_List (Pref); + end if; + end; + + elsif Present (Formal) then + Actuals := New_List; + + else + Actuals := No_List; + end if; + + if Present (Formal) then + 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_Simple_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_Simple_Return_Statement (Loc, + Expression => New_Occurrence_Of (Old_S, Loc)); + + elsif Nkind (Nam) = N_Character_Literal then + Call_Node := + Make_Simple_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 Needs_Finalization (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 Needs_Finalization (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 (T : Entity_Id; S : Uint); + -- Sets the compile time known size (32 bits or less) in the Esize + -- field, of T 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 (T : Entity_Id; 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 & too small, minimum allowed 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; + + -- Always True for scalar types. This is true even for generic formal + -- scalar types. We used to return False in the latter case, but the + -- size is known at compile time, even in the template, we just do + -- not know the exact size but that's not the point of this routine. + + elsif Is_Scalar_Type (T) + or else Is_Task_Type (T) + then + return True; + + -- Array types + + elsif Is_Array_Type (T) then + + -- String literals always have known size, and we can set it + + if Ekind (T) = E_String_Literal_Subtype then + Set_Small_Size (T, Component_Size (T) + * String_Literal_Length (T)); + return True; + + -- Unconstrained types never have known at compile time size + + 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; + + -- Otherwise if component size unknown, then array size unknown + + 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 (T, Esiz); + return True; + end; + + -- Access types always have known at compile time sizes + + elsif Is_Access_Type (T) then + return True; + + -- For non-generic private types, go to underlying type if present + + 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; + + -- Record types + + 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_Component_Or_Discriminant (T); + while Present (Comp) loop + 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 + -- substitution 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; + + Next_Component_Or_Discriminant (Comp); + end loop; + + if Packed_Size_Known then + Set_Small_Size (T, Packed_Size); + end if; + + return True; + end; + + -- All other cases, size not known at compile time + + 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 Debug_Info_Off (T) then + return; + + elsif Comes_From_Source (T) + or else Debug_Generated_Code + or else Debug_Flag_VV + or else Needs_Debug_Info (T) + 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 + Push_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 + Push_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. + + -- 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 Needs_Finalization (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 + Test_E : Entity_Id := E; + 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 + + Rec_Type : constant Entity_Id := + Scope (Defining_Identifier (Comp_Decl)); + + Decl : constant Node_Id := Parent (Rec_Type); + + 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 + -- In Ada95, the (imprecise) rule is that the current instance of a + -- limited type is aliased. In Ada2005, limitedness must be explicit: + -- either a tagged type, or a limited record. + + if Is_Limited_Type (Rec_Type) + and then + (Ada_Version < Ada_05 + or else Is_Tagged_Type (Rec_Type)) + then + return; + + elsif Nkind (Decl) = N_Full_Type_Declaration + and then Limited_Present (Type_Definition (Decl)) + then + return; + + else + Traverse (Comp_Decl); + end if; + end Check_Current_Instance; + + ------------------------ + -- Freeze_Record_Type -- + ------------------------ + + procedure Freeze_Record_Type (Rec : Entity_Id) is + Comp : Entity_Id; + IR : Node_Id; + ADC : Node_Id; + Prev : Entity_Id; + + Junk : Boolean; + pragma Warnings (Off, Junk); + + 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). + + function Check_Allocator (N : Node_Id) return Node_Id; + -- If N is an allocator, possibly wrapped in one or more level of + -- qualified expression(s), return the inner allocator node, else + -- return Empty. + + procedure Check_Itype (Typ : Entity_Id); + -- If the component subtype is an access to 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. Similarly, if the component subtype is a + -- regular (not protected) access to subprogram, set the anonymous + -- subprogram type to frozen as well, to prevent an out-of-scope + -- freeze node at some eventual point of call. Protected operations + -- are handled elsewhere. + + --------------------- + -- Check_Allocator -- + --------------------- + + function Check_Allocator (N : Node_Id) return Node_Id is + Inner : Node_Id; + begin + Inner := N; + loop + if Nkind (Inner) = N_Allocator then + return Inner; + elsif Nkind (Inner) = N_Qualified_Expression then + Inner := Expression (Inner); + else + return Empty; + end if; + end loop; + end Check_Allocator; + + ----------------- + -- Check_Itype -- + ----------------- + + procedure Check_Itype (Typ : Entity_Id) is + Desig : constant Entity_Id := Designated_Type (Typ); + + begin + if not Is_Frozen (Desig) + and then Is_Frozen (Base_Type (Desig)) + then + Set_Is_Frozen (Desig); + + -- 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, Desig); + + if No (Result) then + Result := New_List (IR); + else + Append (IR, Result); + end if; + end if; + + elsif Ekind (Typ) = E_Anonymous_Access_Subprogram_Type + and then Convention (Desig) /= Convention_Protected + then + Set_Is_Frozen (Desig); + end if; + end Check_Itype; + + -- Start of processing for Freeze_Record_Type + + 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 + -- 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. This + -- freeze node is used to communicate with the expander, in order + -- to create the controller for the enclosing record, and it is + -- deleted afterwards (see exp_ch3). It must not be created when + -- expansion is off, because it might appear in the wrong context + -- for the back end. + + elsif Is_Itype (Rec) + and then Has_Delayed_Freeze (Base_Type (Rec)) + and then + Nkind (Associated_Node_For_Itype (Rec)) = + N_Component_Declaration + and then Expander_Active + then + Ensure_Freeze_Node (Rec); + end if; + end if; + + -- Freeze components and embedded subtypes + + Comp := First_Entity (Rec); + Prev := Empty; + while Present (Comp) loop + + -- First handle the (real) component case + + if Ekind (Comp) = E_Component + or else Ekind (Comp) = E_Discriminant + then + declare + CC : constant Node_Id := Component_Clause (Comp); + + begin + -- Freezing a record type freezes the type of each of its + -- components. However, if the type of the component is + -- part of this record, we do not want or need a separate + -- Freeze_Node. Note that Is_Itype is wrong because that's + -- also set in private type cases. We also can't check for + -- the Scope being exactly Rec because of private types and + -- record extensions. + + if Is_Itype (Etype (Comp)) + and then Is_Record_Type (Underlying_Type + (Scope (Etype (Comp)))) + then + Undelay_Type (Etype (Comp)); + end if; + + Freeze_And_Append (Etype (Comp), Loc, Result); + + -- 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. + + 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; + + -- Case of component requires byte alignment + + if Must_Be_On_Byte_Boundary (Etype (Comp)) then + + -- Set the enclosing record to also require byte align + + Set_Must_Be_On_Byte_Boundary (Rec); + + -- Check for component clause that is inconsistent with + -- the required byte boundary alignment. + + if Present (CC) + and then Normalized_First_Bit (Comp) mod + System_Storage_Unit /= 0 + then + Error_Msg_N + ("component & must be byte aligned", + Component_Name (Component_Clause (Comp))); + end if; + end if; + + -- If component clause is present, then deal with the non- + -- default bit order case for Ada 95 mode. The required + -- processing for Ada 2005 mode is handled separately after + -- processing all components. + + -- 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 (CC) + and then Reverse_Bit_Order (Rec) + and then Ekind (E) = E_Record_Type + and then Ada_Version <= Ada_95 + 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); + Error_Msg_N + ("\consider possibility of using " + & "Ada 2005 mode here", CLC); + end if; + + -- Case where field fits in one storage unit + + else + -- Give warning if suspicious component clause + + if Intval (FB) >= System_Storage_Unit + and then Warn_On_Reverse_Bit_Order + 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; + end if; + + -- If the component is an Itype with Delayed_Freeze and is either + -- a record or array subtype and its base type has not yet been + -- frozen, we must remove this from the entity list of this + -- record and put it on the entity list of the scope of its base + -- type. Note that we know that this is not the type of a + -- component since we cleared Has_Delayed_Freeze for it in the + -- previous loop. Thus this must be the Designated_Type of an + -- access type, which is the type of a component. + + if Is_Itype (Comp) + and then Is_Type (Scope (Comp)) + and then Is_Composite_Type (Comp) + and then Base_Type (Comp) /= Comp + and then Has_Delayed_Freeze (Comp) + and then not Is_Frozen (Base_Type (Comp)) + then + declare + Will_Be_Frozen : Boolean := False; + S : Entity_Id; + + begin + -- We have a pretty bad kludge here. Suppose Rec is subtype + -- being defined in a subprogram that's created as part of + -- the freezing of Rec'Base. In that case, we know that + -- Comp'Base must have already been frozen by the time we + -- get to elaborate this because Gigi doesn't elaborate any + -- bodies until it has elaborated all of the declarative + -- part. But Is_Frozen will not be set at this point because + -- we are processing code in lexical order. + + -- We detect this case by going up the Scope chain of Rec + -- and seeing if we have a subprogram scope before reaching + -- the top of the scope chain or that of Comp'Base. If we + -- do, then mark that Comp'Base will actually be frozen. If + -- so, we merely undelay it. + + S := Scope (Rec); + while Present (S) loop + if Is_Subprogram (S) then + Will_Be_Frozen := True; + exit; + elsif S = Scope (Base_Type (Comp)) then + exit; + end if; + + S := Scope (S); + end loop; + + if Will_Be_Frozen then + Undelay_Type (Comp); + else + if Present (Prev) then + Set_Next_Entity (Prev, Next_Entity (Comp)); + else + Set_First_Entity (Rec, Next_Entity (Comp)); + end if; + + -- Insert in entity list of scope of base type (which + -- must be an enclosing scope, because still unfrozen). + + Append_Entity (Comp, Scope (Base_Type (Comp))); + end if; + end; + + -- 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. + + elsif Is_Access_Type (Etype (Comp)) + and then Present (Parent (Comp)) + and then Present (Expression (Parent (Comp))) + then + declare + Alloc : constant Node_Id := + Check_Allocator (Expression (Parent (Comp))); + + begin + if Present (Alloc) then + + -- 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; + + elsif Is_Itype (Designated_Type (Etype (Comp))) then + Check_Itype (Etype (Comp)); + + else + Freeze_And_Append + (Designated_Type (Etype (Comp)), Loc, Result); + end if; + end if; + end; + + elsif Is_Access_Type (Etype (Comp)) + and then Is_Itype (Designated_Type (Etype (Comp))) + then + Check_Itype (Etype (Comp)); + + 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; + + Prev := Comp; + Next_Entity (Comp); + end loop; + + -- Deal with pragma Bit_Order + + if Reverse_Bit_Order (Rec) and then Base_Type (Rec) = Rec then + if not Placed_Component 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); + + -- Here is where we do Ada 2005 processing for bit order (the Ada + -- 95 case was already taken care of above). + + elsif Ada_Version >= Ada_05 then + Adjust_Record_For_Reverse_Bit_Order (Rec); + end if; + end if; + + -- Set OK_To_Reorder_Components depending on debug flags + + if Rec = Base_Type (Rec) + and then Convention (Rec) = Convention_Ada + then + if (Has_Discriminants (Rec) and then Debug_Flag_Dot_V) + or else + (not Has_Discriminants (Rec) and then Debug_Flag_Dot_R) + then + Set_OK_To_Reorder_Components (Rec); + end if; + end if; + + -- Check for useless pragma Pack when all components placed. We only + -- do this check for record types, not subtypes, since a subtype may + -- have all its components placed, and it still makes perfectly good + -- sense to pack other subtypes or the parent type. We do not give + -- this warning if Optimize_Alignment is set to Space, since the + -- pragma Pack does have an effect in this case (it always resets + -- the alignment to one). + + if Ekind (Rec) = E_Record_Type + and then Is_Packed (Rec) + and then not Unplaced_Component + and then Optimize_Alignment /= 'S' + then + -- Reset packed status. Probably not necessary, but we do it so + -- that there is no chance of the back end doing something strange + -- with this redundant indication of packing. + + Set_Is_Packed (Rec, False); + + -- Give warning if redundant constructs warnings on + + if Warn_On_Redundant_Constructs then + Error_Msg_N + ("?pragma Pack has no effect, no unplaced components", + Get_Rep_Pragma (Rec, Name_Pack)); + end if; + 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 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) then + + -- Scan component declaration for likely misuses of current + -- instance, either in a constraint or 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; + + -- Generate warning for applying C or C++ convention to a record + -- with discriminants. This is suppressed for the unchecked union + -- case, since the whole point in this case is interface C. We also + -- do not generate this within instantiations, since we will have + -- generated a message on the template. + + if Has_Discriminants (E) + and then not Is_Unchecked_Union (E) + and then (Convention (E) = Convention_C + or else + Convention (E) = Convention_CPP) + and then Comes_From_Source (E) + and then not In_Instance + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (Base_Type (E)) + then + declare + Cprag : constant Node_Id := Get_Rep_Pragma (E, Name_Convention); + A2 : Node_Id; + + begin + if Present (Cprag) then + A2 := Next (First (Pragma_Argument_Associations (Cprag))); + + if Convention (E) = Convention_C then + Error_Msg_N + ("?variant record has no direct equivalent in C", A2); + else + Error_Msg_N + ("?variant record has no direct equivalent in C++", A2); + end if; + + Error_Msg_NE + ("\?use of convention for type& is dubious", A2, E); + end if; + end; + end if; + end Freeze_Record_Type; + + -- Start of processing for Freeze_Entity + + begin + -- We are going to test for various reasons why this entity need not be + -- frozen here, but in the case of an Itype that's defined within a + -- record, that test actually applies to the record. + + if Is_Itype (E) and then Is_Record_Type (Scope (E)) then + Test_E := Scope (E); + elsif Is_Itype (E) and then Present (Underlying_Type (Scope (E))) + and then Is_Record_Type (Underlying_Type (Scope (E))) + then + Test_E := Underlying_Type (Scope (E)); + end if; + + -- 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. The entity will + -- be frozen in the proper scope after the current generic is analyzed. + + elsif Inside_A_Generic and then External_Ref_In_Generic (Test_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 (e.g. in the case of a deferred constant being used + -- in a default expression). 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 freeze the entity. A subprogram that + -- is a child unit body that acts as a spec does not have a spec that + -- comes from source, but can only come from source. + + elsif In_Open_Scopes (Scope (Test_E)) + and then Scope (Test_E) /= Current_Scope + and then Ekind (Test_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) + or else Is_Child_Unit (S) + then + exit; + else + return No_List; + end if; + end if; + + S := Scope (S); + end loop; + end; + + -- Similarly, an inlined instance body may make reference to global + -- entities, but these references cannot be the proper freezing point + -- for them, and in the absence of inlining freezing will take place in + -- their own scope. Normally instance bodies are analyzed after the + -- enclosing compilation, and everything has been frozen at the proper + -- place, but with front-end inlining an instance body is compiled + -- before the end of the enclosing scope, and as a result out-of-order + -- freezing must be prevented. + + elsif Front_End_Inlining + and then In_Instance_Body + and then Present (Scope (Test_E)) + then + declare + S : Entity_Id := Scope (Test_E); + + begin + while Present (S) loop + if Is_Generic_Instance (S) then + exit; + else + S := Scope (S); + end if; + end loop; + + if No (S) then + return No_List; + end if; + 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; + R_Type : Entity_Id; + Warn_Node : Node_Id; + + 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 + and then not Freezing_Library_Level_Tagged_Type + then + Error_Msg_Node_1 := F_Type; + Error_Msg + ("type& must be fully defined before this point", + Loc); + end if; + end if; + + -- Check suspicious parameter for C function. These tests + -- apply only to exported/imported subprograms. + + if Warn_On_Export_Import + and then Comes_From_Source (E) + and then (Convention (E) = Convention_C + or else + Convention (E) = Convention_CPP) + and then (Is_Imported (E) or else Is_Exported (E)) + and then Convention (E) /= Convention (Formal) + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (F_Type) + and then not Has_Warnings_Off (Formal) + then + Error_Msg_Qual_Level := 1; + + -- Check suspicious use of fat C pointer + + if Is_Access_Type (F_Type) + and then Esize (F_Type) > Ttypes.System_Address_Size + then + Error_Msg_N + ("?type of & does not correspond " + & "to C pointer!", Formal); + + -- Check suspicious return of boolean + + elsif Root_Type (F_Type) = Standard_Boolean + and then Convention (F_Type) = Convention_Ada + and then not Has_Warnings_Off (F_Type) + and then not Has_Size_Clause (F_Type) + then + Error_Msg_N + ("?& is an 8-bit Ada Boolean, " + & "use char in C!", Formal); + + -- Check suspicious tagged type + + elsif (Is_Tagged_Type (F_Type) + or else (Is_Access_Type (F_Type) + and then + Is_Tagged_Type + (Designated_Type (F_Type)))) + and then Convention (E) = Convention_C + then + Error_Msg_N + ("?& is a tagged type which does not " + & "correspond to any C type!", Formal); + + -- Check wrong convention subprogram pointer + + elsif Ekind (F_Type) = E_Access_Subprogram_Type + and then not Has_Foreign_Convention (F_Type) + then + Error_Msg_N + ("?subprogram pointer & should " + & "have foreign convention!", Formal); + Error_Msg_Sloc := Sloc (F_Type); + Error_Msg_NE + ("\?add Convention pragma to declaration of &#", + Formal, F_Type); + end if; + + Error_Msg_Qual_Level := 0; + end if; + + -- Check for unconstrained array in exported foreign + -- convention case. + + if Has_Foreign_Convention (E) + 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; + + -- If this is an inherited operation, place the + -- warning on the derived type declaration, rather + -- than on the original subprogram. + + if Nkind (Original_Node (Parent (E))) = + N_Full_Type_Declaration + then + Warn_Node := Parent (E); + + if Formal = First_Formal (E) then + Error_Msg_NE + ("?in inherited operation&", Warn_Node, E); + end if; + else + Warn_Node := Formal; + end if; + + Error_Msg_NE + ("?type of argument& is unconstrained array", + Warn_Node, Formal); + Error_Msg_NE + ("?foreign caller must pass bounds explicitly", + Warn_Node, Formal); + Error_Msg_Qual_Level := 0; + end if; + + -- Ada 2005 (AI-326): Check wrong use of tag incomplete + -- types with unknown discriminants. For example: + + -- type T (<>) is tagged; + -- procedure P (X : access T); -- ERROR + -- procedure P (X : T); -- ERROR + + if not From_With_Type (F_Type) then + if Is_Access_Type (F_Type) then + F_Type := Designated_Type (F_Type); + end if; + + if Ekind (F_Type) = E_Incomplete_Type + and then Is_Tagged_Type (F_Type) + and then not Is_Class_Wide_Type (F_Type) + and then No (Full_View (F_Type)) + and then Unknown_Discriminants_Present + (Parent (F_Type)) + and then No (Stored_Constraint (F_Type)) + then + Error_Msg_N + ("(Ada 2005): invalid use of unconstrained tagged" + & " incomplete type", E); + + -- If the formal is an anonymous_access_to_subprogram + -- freeze the subprogram type as well, to prevent + -- scope anomalies in gigi, because there is no other + -- clear point at which it could be frozen. + + elsif Is_Itype (Etype (Formal)) + and then Ekind (F_Type) = E_Subprogram_Type + then + Freeze_And_Append (F_Type, Loc, Result); + end if; + end if; + + Next_Formal (Formal); + end loop; + + -- Case of function + + if Ekind (E) = E_Function then + + -- Freeze return type + + R_Type := Etype (E); + Freeze_And_Append (R_Type, Loc, Result); + + -- Check suspicious return type for C function + + if Warn_On_Export_Import + and then (Convention (E) = Convention_C + or else + Convention (E) = Convention_CPP) + and then (Is_Imported (E) or else Is_Exported (E)) + then + -- Check suspicious return of fat C pointer + + if Is_Access_Type (R_Type) + and then Esize (R_Type) > Ttypes.System_Address_Size + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (R_Type) + then + Error_Msg_N + ("?return type of& does not " + & "correspond to C pointer!", E); + + -- Check suspicious return of boolean + + elsif Root_Type (R_Type) = Standard_Boolean + and then Convention (R_Type) = Convention_Ada + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (R_Type) + and then not Has_Size_Clause (R_Type) + then + Error_Msg_N + ("?return type of & is an 8-bit " + & "Ada Boolean, use char in C!", E); + + -- Check suspicious return tagged type + + elsif (Is_Tagged_Type (R_Type) + or else (Is_Access_Type (R_Type) + and then + Is_Tagged_Type + (Designated_Type (R_Type)))) + and then Convention (E) = Convention_C + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (R_Type) + then + Error_Msg_N + ("?return type of & does not " + & "correspond to C type!", E); + + -- Check return of wrong convention subprogram pointer + + elsif Ekind (R_Type) = E_Access_Subprogram_Type + and then not Has_Foreign_Convention (R_Type) + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (R_Type) + then + Error_Msg_N + ("?& should return a foreign " + & "convention subprogram pointer", E); + Error_Msg_Sloc := Sloc (R_Type); + Error_Msg_NE + ("\?add Convention pragma to declaration of& #", + E, R_Type); + end if; + end if; + + if Is_Array_Type (Etype (E)) + and then not Is_Constrained (Etype (E)) + and then not Is_Imported (E) + and then Has_Foreign_Convention (E) + and then Warn_On_Export_Import + and then not Has_Warnings_Off (E) + and then not Has_Warnings_Off (Etype (E)) + then + Error_Msg_N + ("?foreign convention function& should not " & + "return unconstrained array!", E); + + -- Ada 2005 (AI-326): Check wrong use of tagged + -- incomplete type + + -- type T is tagged; + -- function F (X : Boolean) return T; -- ERROR + + -- The type must be declared in the current scope for the + -- use to be legal, and the full view must be available + -- when the construct that mentions it is frozen. + + elsif Ekind (Etype (E)) = E_Incomplete_Type + and then Is_Tagged_Type (Etype (E)) + and then No (Full_View (Etype (E))) + and then not Is_Value_Type (Etype (E)) + then + Error_Msg_N + ("(Ada 2005): invalid use of tagged incomplete type", + 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; + + -- We don't freeze internal subprograms, because we don't normally + -- want addition of extra formals or mechanism setting to happen + -- for those. However we do pass through predefined dispatching + -- cases, since extra formals may be needed in some cases, such as + -- for the stream 'Input function (build-in-place formals). + + if not Is_Internal (E) + or else Is_Predefined_Dispatching_Operation (E) + then + Freeze_Subprogram (E); + end if; + + -- Here for other than a subprogram or type + + else + -- For a generic package, freeze types within, so that proper + -- cross-reference information is generated for tagged types. + -- This is the only freeze processing needed for generic packages. + + if Ekind (E) = E_Generic_Package then + declare + T : Entity_Id; + + begin + T := First_Entity (E); + while Present (T) loop + if Is_Type (T) then + Generate_Prim_Op_References (T); + end if; + + Next_Entity (T); + end loop; + end; + + -- If entity has a type, and it is not a generic unit, then + -- freeze it first (RM 13.14(10)). + + elsif Present (Etype (E)) + and then Ekind (E) /= E_Generic_Function + then + Freeze_And_Append (Etype (E), Loc, Result); + end if; + + -- Special processing for objects created by object declaration + + if Nkind (Declaration_Node (E)) = N_Object_Declaration then + + -- 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. + + Validate_Object_Declaration (Declaration_Node (E)); + + -- If there is an address clause, check that it is valid + + Check_Address_Clause (E); + + -- If the object needs any kind of default initialization, an + -- error must be issued if No_Default_Initialization applies. + -- The check doesn't apply to imported objects, which are not + -- ever default initialized, and is why the check is deferred + -- until freezing, at which point we know if Import applies. + -- Deferred constants are also exempted from this test because + -- their completion is explicit, or through an import pragma. + + if Ekind (E) = E_Constant + and then Present (Full_View (E)) + then + null; + + elsif Comes_From_Source (E) + and then not Is_Imported (E) + and then not Has_Init_Expression (Declaration_Node (E)) + and then + ((Has_Non_Null_Base_Init_Proc (Etype (E)) + and then not No_Initialization (Declaration_Node (E)) + and then not Is_Value_Type (Etype (E)) + and then not Suppress_Init_Proc (Etype (E))) + or else + (Needs_Simple_Initialization (Etype (E)) + and then not Is_Internal (E))) + then + Check_Restriction + (No_Default_Initialization, Declaration_Node (E)); + end if; + + -- For imported objects, set Is_Public unless there is also an + -- address clause, which means that there is no external symbol + -- needed for the Import (Is_Public may still be set for other + -- unrelated reasons). Note that we delayed this processing + -- till freeze time so that we can be sure not to set the flag + -- if there is an address clause. If there is such a clause, + -- then the only purpose of the Import pragma is to suppress + -- implicit initialization. + + if Is_Imported (E) + and then No (Address_Clause (E)) + then + Set_Is_Public (E); + end if; + + -- For convention C objects of an enumeration type, warn if + -- the size is not integer size and no explicit size given. + -- Skip warning for Boolean, and Character, assume programmer + -- expects 8-bit sizes for these cases. + + if (Convention (E) = Convention_C + or else + Convention (E) = Convention_CPP) + and then Is_Enumeration_Type (Etype (E)) + and then not Is_Character_Type (Etype (E)) + and then not Is_Boolean_Type (Etype (E)) + and then Esize (Etype (E)) < Standard_Integer_Size + and then not Has_Size_Clause (E) + then + Error_Msg_Uint_1 := UI_From_Int (Standard_Integer_Size); + Error_Msg_N + ("?convention C enumeration object has size less than ^", + E); + Error_Msg_N ("\?use explicit size clause to set size", E); + end if; + 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 Has_Rep_Pragma (E, Name_Atomic) + or else + Has_Rep_Pragma (E, Name_Atomic_Components) + then + Error_Msg_N + ("stand alone atomic constant must be " & + "imported (RM C.6(13))", E); + + elsif Has_Rep_Pragma (E, Name_Volatile) + or else + Has_Rep_Pragma (E, Name_Volatile_Components) + then + Error_Msg_N + ("stand alone volatile constant must be " & + "imported (RM 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 + -- We used to check here that a full type must have preelaborable + -- initialization if it completes a private type specified with + -- pragma Preelaborable_Intialization, but that missed cases where + -- the types occur within a generic package, since the freezing + -- that occurs within a containing scope generally skips traversal + -- of a generic unit's declarations (those will be frozen within + -- instances). This check was moved to Analyze_Package_Specification. + + -- 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 + + -- Before we do anything else, a specialized test for the case of + -- a size given for an array 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. Also if pragma + -- Implicit_Packing is set, this is where the packing occurs. + + -- The reason we do this so early is that the processing in the + -- automatic packing case affects the layout of the base type, so + -- it must be done before we freeze the base type. + + if Is_Array_Type (E) then + declare + Lo, Hi : Node_Id; + Ctyp : constant Entity_Id := Component_Type (E); + + begin + -- Check enabling conditions. These are straightforward + -- except for the test for a limited composite type. This + -- eliminates the rare case of a array of limited components + -- where there are issues of whether or not we can go ahead + -- and pack the array (since we can't freely pack and unpack + -- arrays if they are limited). + + -- Note that we check the root type explicitly because the + -- whole point is we are doing this test before we have had + -- a chance to freeze the base type (and it is that freeze + -- action that causes stuff to be inherited). + + if Present (Size_Clause (E)) + and then Known_Static_Esize (E) + and then not Is_Packed (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) + and then not Is_Limited_Composite (E) + and then not Is_Packed (Root_Type (E)) + and then not Has_Component_Size_Clause (Root_Type (E)) + 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); + SZ : constant Node_Id := Size_Clause (E); + Btyp : constant Entity_Id := Base_Type (E); + + -- What we are looking for here is the situation where + -- the RM_Size 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 RM_Size (E) = Len * Rsiz + and then Rsiz mod System_Storage_Unit /= 0 + then + -- For implicit packing mode, just set the + -- component size silently + + if Implicit_Packing then + Set_Component_Size (Btyp, Rsiz); + Set_Is_Bit_Packed_Array (Btyp); + Set_Is_Packed (Btyp); + Set_Has_Non_Standard_Rep (Btyp); + + -- Otherwise give an error message + + else + Error_Msg_NE + ("size given for& too small", SZ, E); + Error_Msg_N + ("\use explicit pragma Pack " + & "or use pragma Implicit_Packing", SZ); + end if; + end if; + end; + end if; + end if; + end; + end if; + + -- 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); + + 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 interfere 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 size (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; + + -- Case of component size that may result in packing + + if 1 <= Csiz and then Csiz <= 64 then + declare + Ent : constant Entity_Id := + First_Subtype (E); + Pack_Pragma : constant Node_Id := + Get_Rep_Pragma (Ent, Name_Pack); + Comp_Size_C : constant Node_Id := + Get_Attribute_Definition_Clause + (Ent, Attribute_Component_Size); + begin + -- Warn if we have pack and component size so that + -- the pack is ignored. + + -- Note: here we must check for the presence of a + -- component size before checking for a Pack pragma + -- to deal with the case where the array type is a + -- derived type whose parent is currently private. + + if Present (Comp_Size_C) + and then Has_Pragma_Pack (Ent) + then + Error_Msg_Sloc := Sloc (Comp_Size_C); + Error_Msg_NE + ("?pragma Pack for& ignored!", + Pack_Pragma, Ent); + Error_Msg_N + ("\?explicit component size given#!", + Pack_Pragma); + end if; + + -- Set component size if not already set by a + -- component size clause. + + if not Present (Comp_Size_C) then + Set_Component_Size (E, Csiz); + end if; + + -- Check for base type of 8, 16, 32 bits, where an + -- unsigned subtype has a length one less than the + -- base type (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 Present (Comp_Size_C) + 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; + + if Present (Pack_Pragma) then + Error_Msg_N + ("?pragma Pack causes component size " + & "to be ^!", Pack_Pragma); + Error_Msg_N + ("\?use Component_Size to set " + & "desired value!", Pack_Pragma); + 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 pragma Pack 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; + 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))); + Adjust_Esize_Alignment (E); + end if; + end if; + + -- For bit-packed arrays, check the size + + if Is_Bit_Packed_Array (E) + and then Known_RM_Size (E) + then + declare + SizC : constant Node_Id := Size_Clause (E); + + Discard : Boolean; + pragma Warnings (Off, Discard); + + begin + -- It is not clear if it is possible to have no size + -- clause at this stage, but it is not worth worrying + -- about. Post 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, RM_Size (E), Discard); + else + Check_Size (E, E, RM_Size (E), Discard); + end if; + end; + end if; + + -- 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; + + 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. But + -- do not override explicit existing size values. If the + -- ancestor subtype is constrained the packed_array_type + -- will be inherited from it, but the size may have been + -- provided already, and must not be overridden either. + + if not Has_Size_Clause (E) + and then + (No (Ancestor_Subtype (E)) + or else not Has_Size_Clause (Ancestor_Subtype (E))) + then + Set_Esize (E, Esize (Packed_Array_Type (E))); + Set_RM_Size (E, RM_Size (Packed_Array_Type (E))); + end if; + + if not Has_Alignment_Clause (E) then + Set_Alignment (E, Alignment (Packed_Array_Type (E))); + end if; + end if; + + -- For non-packed arrays set the alignment of the array to the + -- alignment of the component type if it is unknown. Skip this + -- in atomic case (atomic arrays may need larger alignments). + + if not Is_Packed (E) + and then Unknown_Alignment (E) + and then Known_Alignment (Ctyp) + and then Known_Static_Component_Size (E) + and then Known_Static_Esize (Ctyp) + and then Esize (Ctyp) = Component_Size (E) + and then not Is_Atomic (E) + then + Set_Alignment (E, Alignment (Component_Type (E))); + end if; + end; + + -- 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 base type of the class-wide type is still incomplete, + -- the class-wide remains unfrozen as well. This is legal when + -- E is the formal of a primitive operation of some other type + -- which is being frozen. + + if not Is_Frozen (Root_Type (E)) then + Set_Is_Frozen (E, False); + return Result; + end if; + + -- 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 correspond 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 + if Is_Itype (Etype (Comp)) + and then Underlying_Type (Scope (Etype (Comp))) = E + then + Undelay_Type (Etype (Comp)); + end if; + + 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 + -- The construction of the dispatch table associated with library + -- level tagged types forces freezing of all the primitives of the + -- type, which may cause premature freezing of the partial view. + -- For example: + + -- package Pkg is + -- type T is tagged private; + -- type DT is new T with private; + -- procedure Prim (X : in out T; Y : in out DT'class); + -- private + -- type T is tagged null record; + -- Obj : T; + -- type DT is new T with null record; + -- end; + + -- In this case the type will be frozen later by the usual + -- mechanism: an object declaration, an instantiation, or the + -- end of a declarative part. + + if Is_Library_Level_Tagged_Type (E) + and then not Present (Full_View (E)) + then + Set_Is_Frozen (E, False); + return Result; + + -- Case of full view present + + elsif 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; + + Freeze_Subprogram (E); + + -- Ada 2005 (AI-326): Check wrong use of tag incomplete type + + -- type T is tagged; + -- type Acc is access function (X : T) return T; -- ERROR + + if Ekind (Etype (E)) = E_Incomplete_Type + and then Is_Tagged_Type (Etype (E)) + and then No (Full_View (Etype (E))) + and then not Is_Value_Type (Etype (E)) + then + Error_Msg_N + ("(Ada 2005): invalid use of tagged incomplete type", E); + end if; + + -- 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 Is_Access_Protected_Subprogram_Type (E) then + + -- AI-326: Check wrong use of tagged incomplete types + + -- type T is tagged; + -- type As3D is access protected + -- function (X : Float) return T; -- ERROR + + declare + Etyp : Entity_Id; + + begin + Etyp := Etype (Directly_Designated_Type (E)); + + if Is_Class_Wide_Type (Etyp) then + Etyp := Etype (Etyp); + end if; + + if Ekind (Etyp) = E_Incomplete_Type + and then Is_Tagged_Type (Etyp) + and then No (Full_View (Etyp)) + and then not Is_Value_Type (Etype (E)) + then + Error_Msg_N + ("(Ada 2005): invalid use of tagged incomplete type", E); + end if; + end; + + if Present (Equivalent_Type (E)) then + Freeze_And_Append (Equivalent_Type (E), Loc, Result); + end if; + 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 + ("`&''%` too small, minimum allowed is 2.0'*'*(-80)", E); + + elsif Small_Value (E) > Ureal_2_80 then + Error_Msg_Name_1 := Name_Small; + Error_Msg_N + ("`&''%` too large, maximum allowed 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 + ("`&''%` too small, minimum allowed 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 + ("`&''%` too large, maximum allowed 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) then + + -- Check restriction for standard storage pool + + if No (Associated_Storage_Pool (E)) then + Check_Restriction (No_Standard_Storage_Pools, E); + end if; + + -- Deal with error message for pure access type. This is not an + -- error in Ada 2005 if there is no pool (see AI-366). + + if Is_Pure_Unit_Access_Type (E) + and then (Ada_Version < Ada_05 + or else not No_Pool_Assigned (E)) + then + Error_Msg_N ("named access type not allowed in pure unit", E); + + if Ada_Version >= Ada_05 then + Error_Msg_N + ("\would be legal if Storage_Size of 0 given?", E); + + elsif No_Pool_Assigned (E) then + Error_Msg_N + ("\would be legal in Ada 2005?", E); + + else + Error_Msg_N + ("\would be legal in Ada 2005 if " + & "Storage_Size of 0 given?", E); + end if; + end if; + end if; + + -- Case of composite types + + if Is_Composite_Type (E) then + + -- 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), which 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 references to primitive operations for a tagged type + + Generate_Prim_Op_References (E); + + -- 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 alignment 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 + -- Suppress 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 such 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; + + -- A final pass over record types with discriminants. If the type + -- has an incomplete declaration, there may be constrained access + -- subtypes declared elsewhere, which do not depend on the discrimi- + -- nants of the type, and which are used as component types (i.e. + -- the full view is a recursive type). The designated types of these + -- subtypes can only be elaborated after the type itself, and they + -- need an itype reference. + + if Ekind (E) = E_Record_Type + and then Has_Discriminants (E) + then + declare + Comp : Entity_Id; + IR : Node_Id; + Typ : Entity_Id; + + begin + Comp := First_Component (E); + + while Present (Comp) loop + Typ := Etype (Comp); + + if Ekind (Comp) = E_Component + and then Is_Access_Type (Typ) + and then Scope (Typ) /= E + and then Base_Type (Designated_Type (Typ)) = E + and then Is_Itype (Designated_Type (Typ)) + then + IR := Make_Itype_Reference (Sloc (Comp)); + Set_Itype (IR, Designated_Type (Typ)); + Append (IR, Result); + end if; + + Next_Component (Comp); + end loop; + end; + 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; + end if; + end if; + + return Result; + end Freeze_Entity; + + ----------------------------- + -- Freeze_Enumeration_Type -- + ----------------------------- + + procedure Freeze_Enumeration_Type (Typ : Entity_Id) is + begin + -- By default, if no size clause is present, an enumeration type with + -- Convention C is assumed to interface to a C enum, and has integer + -- size. This applies to types. For subtypes, verify that its base + -- type has no size clause either. + + if Has_Foreign_Convention (Typ) + and then not Has_Size_Clause (Typ) + and then not Has_Size_Clause (Base_Type (Typ)) + and then Esize (Typ) < Standard_Integer_Size + then + Init_Esize (Typ, Standard_Integer_Size); + + else + -- If the enumeration type interfaces to C, and it has a size clause + -- that specifies less than int size, it warrants a warning. The + -- user may intend the C type to be an enum or a char, so this is + -- not by itself an error that the Ada compiler can detect, but it + -- it is a worth a heads-up. For Boolean and Character types we + -- assume that the programmer has the proper C type in mind. + + if Convention (Typ) = Convention_C + and then Has_Size_Clause (Typ) + and then Esize (Typ) /= Esize (Standard_Integer) + and then not Is_Boolean_Type (Typ) + and then not Is_Character_Type (Typ) + then + Error_Msg_N + ("C enum types have the size of a C int?", Size_Clause (Typ)); + end if; + + Adjust_Esize_For_Alignment (Typ); + end if; + end Freeze_Enumeration_Type; + + ----------------------- + -- Freeze_Expression -- + ----------------------- + + procedure Freeze_Expression (N : Node_Id) is + In_Spec_Exp : constant Boolean := In_Spec_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, stream subprogram, or renaming as body). + -- If so, this is not a freezing context. + + ----------------- + -- In_Exp_Body -- + ----------------- + + function In_Exp_Body (N : Node_Id) return Boolean is + P : Node_Id; + Id : Entity_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 + Id := Defining_Unit_Name (Specification (P)); + + if Nkind (Id) = N_Defining_Identifier + and then (Is_Init_Proc (Id) or else + Is_TSS (Id, TSS_Stream_Input) or else + Is_TSS (Id, TSS_Stream_Output) or else + Is_TSS (Id, TSS_Stream_Read) or else + Is_TSS (Id, TSS_Stream_Write) or else + Nkind (Original_Node (P)) = + N_Subprogram_Renaming_Declaration) + 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_Spec_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 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_Spec_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-overloaded 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 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 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. + + -- If the expression appears in a constrained subcomponent of an + -- enclosing record declaration, the freeze nodes must be attached to + -- the outer record type so they can eventually be placed in the + -- enclosing declaration list. + + -- 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 and other spec 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_Spec_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; + Pos : Int := Scope_Stack.Last; + + 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; + + -- The current scope may be that of a constrained component of + -- an enclosing record declaration, which is above the current + -- scope in the scope stack. + + if Is_Record_Type (Scope (Current_Scope)) then + Pos := Pos - 1; + end if; + + if Is_Non_Empty_List (Freeze_Nodes) then + if No (Scope_Stack.Table (Pos).Pending_Freeze_Actions) then + Scope_Stack.Table (Pos).Pending_Freeze_Actions := + Freeze_Nodes; + else + Append_List (Freeze_Nodes, Scope_Stack.Table + (Pos).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 spec-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_Spec_Expression mode to propagate these freeze actions. + -- This also means they get properly analyzed and expanded. + + In_Spec_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; + + -- Restore In_Spec_Expression flag + + In_Spec_Expression := In_Spec_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. + + ----------- + -- Fsize -- + ----------- + + 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 accommodated 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; + + -- If the value went from negative to zero, then we have the + -- case where Loval_Incl_EP is the model number just below + -- zero, so we want to stick to the negative value for the + -- base type to maintain the condition that the size will + -- include signed values. + + if Typ = Btyp + and then UR_Is_Zero (Loval_Excl_EP) + then + Loval_Excl_EP := Loval_Incl_EP; + end if; + + 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 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 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 allowed 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 allowed 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 allowed 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 expression type 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 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)); + + 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 + -- 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 + F := First_Formal (E); + while Present (F) loop + if Warn_On_Export_Import + and then Present (Default_Value (F)) + then + Error_Msg_N + ("?parameter cannot be defaulted in non-Ada call", + Default_Value (F)); + end if; + + Next_Formal (F); + end loop; + end if; + end if; + + -- For VMS, descriptor mechanisms for parameters are allowed only + -- for imported/exported subprograms. Moreover, the NCA descriptor + -- is not allowed for parameters of exported subprograms. + + if OpenVMS_On_Target then + if Is_Exported (E) then + F := First_Formal (E); + while Present (F) loop + if Mechanism (F) = By_Descriptor_NCA then + Error_Msg_N + ("'N'C'A' descriptor for parameter not permitted", F); + Error_Msg_N + ("\can only be used for imported subprogram", F); + end if; + + Next_Formal (F); + end loop; + + elsif not Is_Imported (E) then + F := First_Formal (E); + while Present (F) loop + if Mechanism (F) in Descriptor_Codes then + Error_Msg_N + ("descriptor mechanism for parameter not permitted", F); + Error_Msg_N + ("\can only be used for imported/exported subprogram", F); + end if; + + Next_Formal (F); + end loop; + end if; + end if; + + -- Pragma Inline_Always is disallowed for dispatching subprograms + -- because the address of such subprograms is saved in the dispatch + -- table to support dispatching calls, and dispatching calls cannot + -- be inlined. This is consistent with the restriction against using + -- 'Access or 'Address on an Inline_Always subprogram. + + if Is_Dispatching_Operation (E) + and then Has_Pragma_Inline_Always (E) + then + Error_Msg_N + ("pragma Inline_Always not allowed for dispatching subprograms", E); + end if; + + -- Because of the implicit representation of inherited predefined + -- operators in the front-end, the overriding status of the operation + -- may be affected when a full view of a type is analyzed, and this is + -- not captured by the analysis of the corresponding type declaration. + -- Therefore the correctness of a not-overriding indicator must be + -- rechecked when the subprogram is frozen. + + if Nkind (E) = N_Defining_Operator_Symbol + and then not Error_Posted (Parent (E)) + then + Check_Overriding_Indicator (E, Empty, Is_Primitive (E)); + end if; + end Freeze_Subprogram; + + ---------------------- + -- Is_Fully_Defined -- + ---------------------- + + function Is_Fully_Defined (T : Entity_Id) return Boolean is + begin + if Ekind (T) = E_Class_Wide_Type then + return Is_Fully_Defined (Etype (T)); + + elsif Is_Array_Type (T) then + return Is_Fully_Defined (Component_Type (T)); + + elsif Is_Record_Type (T) + and not Is_Private_Type (T) + then + -- Verify that the record type has no components with private types + -- without completion. + + declare + Comp : Entity_Id; + + begin + Comp := First_Component (T); + + while Present (Comp) loop + if not Is_Fully_Defined (Etype (Comp)) then + return False; + end if; + + Next_Component (Comp); + end loop; + return True; + end; + + else + return not Is_Private_Type (T) + or else Present (Full_View (Base_Type (T))); + end if; + end Is_Fully_Defined; + + --------------------------------- + -- Generate_Prim_Op_References -- + --------------------------------- + + procedure Generate_Prim_Op_References (Typ : Entity_Id) is + Base_T : Entity_Id; + Prim : Elmt_Id; + Prim_List : Elist_Id; + Ent : Entity_Id; + + begin + -- Handle subtypes of synchronized types + + if Ekind (Typ) = E_Protected_Subtype + or else Ekind (Typ) = E_Task_Subtype + then + Base_T := Etype (Typ); + else + Base_T := Typ; + end if; + + -- References to primitive operations are only relevant for tagged types + + if not Is_Tagged_Type (Base_T) + or else Is_Class_Wide_Type (Base_T) + then + return; + end if; + + -- Ada 2005 (AI-345): For synchronized types generate reference + -- to the wrapper that allow us to dispatch calls through their + -- implemented abstract interface types. + + -- The check for Present here is to protect against previously + -- reported critical errors. + + if Is_Concurrent_Type (Base_T) + and then Present (Corresponding_Record_Type (Base_T)) + then + Prim_List := Primitive_Operations + (Corresponding_Record_Type (Base_T)); + else + Prim_List := Primitive_Operations (Base_T); + end if; + + if No (Prim_List) then + return; + end if; + + Prim := First_Elmt (Prim_List); + while Present (Prim) loop + + -- If the operation is derived, get the original for cross-reference + -- reference purposes (it is the original for which we want the xref + -- and for which the comes_from_source test must be performed). + + Ent := Node (Prim); + while Present (Alias (Ent)) loop + Ent := Alias (Ent); + end loop; + + Generate_Reference (Typ, Ent, 'p', Set_Ref => False); + Next_Elmt (Prim); + end loop; + end Generate_Prim_Op_References; + + --------------------------------- + -- Process_Default_Expressions -- + --------------------------------- + + procedure Process_Default_Expressions + (E : Entity_Id; + After : in out Node_Id) + is + Loc : constant Source_Ptr := Sloc (E); + Dbody : Node_Id; + Formal : Node_Id; + Dcopy : Node_Id; + Dnam : Entity_Id; + + begin + Set_Default_Expressions_Processed (E); + + -- A subprogram instance and its associated anonymous subprogram share + -- their signature. The default expression functions are defined in the + -- wrapper packages for the anonymous subprogram, and should not be + -- generated again for the instance. + + if Is_Generic_Instance (E) + and then Present (Alias (E)) + and then Default_Expressions_Processed (Alias (E)) + then + return; + end if; + + Formal := First_Formal (E); + while Present (Formal) loop + if Present (Default_Value (Formal)) then + + -- We work with a copy of the default expression because we + -- do not want to disturb the original, since this would mess + -- up the conformance checking. + + Dcopy := New_Copy_Tree (Default_Value (Formal)); + + -- The analysis of the expression may generate insert actions, + -- which of course must not be executed. We wrap those actions + -- in a procedure that is not called, and later on eliminated. + -- The following cases have no side-effects, and are analyzed + -- directly. + + if Nkind (Dcopy) = N_Identifier + or else Nkind (Dcopy) = N_Expanded_Name + or else Nkind (Dcopy) = N_Integer_Literal + or else (Nkind (Dcopy) = N_Real_Literal + and then not Vax_Float (Etype (Dcopy))) + or else Nkind (Dcopy) = N_Character_Literal + or else Nkind (Dcopy) = N_String_Literal + or else Known_Null (Dcopy) + or else (Nkind (Dcopy) = N_Attribute_Reference + and then + Attribute_Name (Dcopy) = Name_Null_Parameter) + then + + -- If there is no default function, we must still do a full + -- analyze call on the default value, to ensure that all error + -- checks are performed, e.g. those associated with static + -- evaluation. Note: this branch will always be taken if the + -- analyzer is turned off (but we still need the error checks). + + -- Note: the setting of parent here is to meet the requirement + -- that we can only analyze the expression while attached to + -- the tree. Really the requirement is that the parent chain + -- be set, we don't actually need to be in the tree. + + Set_Parent (Dcopy, Declaration_Node (Formal)); + Analyze (Dcopy); + + -- Default expressions are resolved with their own type if the + -- context is generic, to avoid anomalies with private types. + + if Ekind (Scope (E)) = E_Generic_Package then + Resolve (Dcopy); + else + Resolve (Dcopy, Etype (Formal)); + end if; + + -- If that resolved expression will raise constraint error, + -- then flag the default value as raising constraint error. + -- This allows a proper error message on the calls. + + if Raises_Constraint_Error (Dcopy) then + Set_Raises_Constraint_Error (Default_Value (Formal)); + end if; + + -- If the default is a parameterless call, we use the name of + -- the called function directly, and there is no body to build. + + elsif Nkind (Dcopy) = N_Function_Call + and then No (Parameter_Associations (Dcopy)) + then + null; + + -- Else construct and analyze the body of a wrapper procedure + -- that contains an object declaration to hold the expression. + -- Given that this is done only to complete the analysis, it + -- simpler to build a procedure than a function which might + -- involve secondary stack expansion. + + else + Dnam := + Make_Defining_Identifier (Loc, New_Internal_Name ('D')); + + Dbody := + Make_Subprogram_Body (Loc, + Specification => + Make_Procedure_Specification (Loc, + Defining_Unit_Name => Dnam), + + Declarations => New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, + New_Internal_Name ('T')), + Object_Definition => + New_Occurrence_Of (Etype (Formal), Loc), + Expression => New_Copy_Tree (Dcopy))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List)); + + Set_Scope (Dnam, Scope (E)); + Set_Assignment_OK (First (Declarations (Dbody))); + Set_Is_Eliminated (Dnam); + Insert_After (After, Dbody); + Analyze (Dbody); + After := Dbody; + end if; + end if; + + Next_Formal (Formal); + end loop; + end Process_Default_Expressions; + + ---------------------------------------- + -- Set_Component_Alignment_If_Not_Set -- + ---------------------------------------- + + procedure Set_Component_Alignment_If_Not_Set (Typ : Entity_Id) is + begin + -- Ignore if not base type, subtypes don't need anything + + if Typ /= Base_Type (Typ) then + return; + end if; + + -- Do not override existing representation + + if Is_Packed (Typ) then + return; + + elsif Has_Specified_Layout (Typ) then + return; + + elsif Component_Alignment (Typ) /= Calign_Default then + return; + + else + Set_Component_Alignment + (Typ, Scope_Stack.Table + (Scope_Stack.Last).Component_Alignment_Default); + end if; + end Set_Component_Alignment_If_Not_Set; + + ------------------ + -- Undelay_Type -- + ------------------ + + procedure Undelay_Type (T : Entity_Id) is + begin + Set_Has_Delayed_Freeze (T, False); + Set_Freeze_Node (T, Empty); + + -- Since we don't want T to have a Freeze_Node, we don't want its + -- Full_View or Corresponding_Record_Type to have one either. + + -- ??? Fundamentally, this whole handling is a kludge. What we really + -- want is to be sure that for an Itype that's part of record R and is a + -- subtype of type T, that it's frozen after the later of the freeze + -- points of R and T. We have no way of doing that directly, so what we + -- do is force most such Itypes to be frozen as part of freezing R via + -- this procedure and only delay the ones that need to be delayed + -- (mostly the designated types of access types that are defined as part + -- of the record). + + if Is_Private_Type (T) + and then Present (Full_View (T)) + and then Is_Itype (Full_View (T)) + and then Is_Record_Type (Scope (Full_View (T))) + then + Undelay_Type (Full_View (T)); + end if; + + if Is_Concurrent_Type (T) + and then Present (Corresponding_Record_Type (T)) + and then Is_Itype (Corresponding_Record_Type (T)) + and then Is_Record_Type (Scope (Corresponding_Record_Type (T))) + then + Undelay_Type (Corresponding_Record_Type (T)); + end if; + end Undelay_Type; + + ------------------ + -- Warn_Overlay -- + ------------------ + + procedure Warn_Overlay + (Expr : Node_Id; + Typ : Entity_Id; + Nam : Entity_Id) + is + Ent : constant Entity_Id := Entity (Nam); + -- The object to which the address clause applies + + Init : Node_Id; + Old : Entity_Id := Empty; + Decl : Node_Id; + + begin + -- No warning if address clause overlay warnings are off + + if not Address_Clause_Overlay_Warnings then + return; + end if; + + -- No warning if there is an explicit initialization + + Init := Original_Node (Expression (Declaration_Node (Ent))); + + if Present (Init) and then Comes_From_Source (Init) then + return; + end if; + + -- We only give the warning for non-imported entities of a type for + -- which a non-null base init proc is defined (or for access types which + -- have implicit null initialization). + + if Present (Expr) + and then (Has_Non_Null_Base_Init_Proc (Typ) + or else Is_Access_Type (Typ)) + and then not Is_Imported (Ent) + then + if Nkind (Expr) = N_Attribute_Reference + and then Is_Entity_Name (Prefix (Expr)) + then + Old := Entity (Prefix (Expr)); + + elsif Is_Entity_Name (Expr) + and then Ekind (Entity (Expr)) = E_Constant + then + Decl := Declaration_Node (Entity (Expr)); + + if Nkind (Decl) = N_Object_Declaration + and then Present (Expression (Decl)) + and then Nkind (Expression (Decl)) = N_Attribute_Reference + and then Is_Entity_Name (Prefix (Expression (Decl))) + then + Old := Entity (Prefix (Expression (Decl))); + + elsif Nkind (Expr) = N_Function_Call then + return; + end if; + + -- A function call (most likely to To_Address) is probably not an + -- overlay, so skip warning. Ditto if the function call was inlined + -- and transformed into an entity. + + elsif Nkind (Original_Node (Expr)) = N_Function_Call then + return; + end if; + + Decl := Next (Parent (Expr)); + + -- If a pragma Import follows, we assume that it is for the current + -- target of the address clause, and skip the warning. + + if Present (Decl) + and then Nkind (Decl) = N_Pragma + and then Pragma_Name (Decl) = Name_Import + then + return; + end if; + + if Present (Old) then + Error_Msg_Node_2 := Old; + Error_Msg_N + ("default initialization of & may modify &?", + Nam); + else + Error_Msg_N + ("default initialization of & may modify overlaid storage?", + Nam); + end if; + + -- Add friendly warning if initialization comes from a packed array + -- component. + + if Is_Record_Type (Typ) then + declare + Comp : Entity_Id; + + begin + Comp := First_Component (Typ); + + while Present (Comp) loop + if Nkind (Parent (Comp)) = N_Component_Declaration + and then Present (Expression (Parent (Comp))) + then + exit; + elsif Is_Array_Type (Etype (Comp)) + and then Present (Packed_Array_Type (Etype (Comp))) + then + Error_Msg_NE + ("\packed array component& " & + "will be initialized to zero?", + Nam, Comp); + exit; + else + Next_Component (Comp); + end if; + end loop; + end; + end if; + + Error_Msg_N + ("\use pragma Import for & to " & + "suppress initialization (RM B.1(24))?", + Nam); + end if; + end Warn_Overlay; + +end Freeze; -- cgit v1.2.3