diff options
Diffstat (limited to 'gcc/ada/freeze.adb')
| -rw-r--r-- | gcc/ada/freeze.adb | 3903 |
1 files changed, 3903 insertions, 0 deletions
diff --git a/gcc/ada/freeze.adb b/gcc/ada/freeze.adb new file mode 100644 index 00000000000..6f4c4c7c7c1 --- /dev/null +++ b/gcc/ada/freeze.adb @@ -0,0 +1,3903 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- F R E E Z E -- +-- -- +-- B o d y -- +-- -- +-- $Revision: 1.281 $ +-- -- +-- Copyright (C) 1992-2001, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Debug; use Debug; +with Einfo; use Einfo; +with Elists; use Elists; +with Errout; use Errout; +with Exp_Ch7; use Exp_Ch7; +with Exp_Ch11; use Exp_Ch11; +with Exp_Pakd; use Exp_Pakd; +with Exp_Util; use Exp_Util; +with Layout; use Layout; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Restrict; use Restrict; +with Sem; use Sem; +with Sem_Cat; use Sem_Cat; +with Sem_Ch6; use Sem_Ch6; +with Sem_Ch7; use Sem_Ch7; +with Sem_Ch8; use Sem_Ch8; +with Sem_Ch13; use Sem_Ch13; +with Sem_Eval; use Sem_Eval; +with Sem_Mech; use Sem_Mech; +with Sem_Prag; use Sem_Prag; +with Sem_Res; use Sem_Res; +with Sem_Util; use Sem_Util; +with Sinfo; use Sinfo; +with Snames; use Snames; +with Stand; use Stand; +with Targparm; use Targparm; +with Tbuild; use Tbuild; +with Ttypes; use Ttypes; +with Uintp; use Uintp; +with Urealp; use Urealp; + +package body Freeze is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Adjust_Esize_For_Alignment (Typ : Entity_Id); + -- Typ is a type that is being frozen. If no size clause is given, + -- but a default Esize has been computed, then this default Esize is + -- adjusted up if necessary to be consistent with a given alignment, + -- but never to a value greater than Long_Long_Integer'Size. This + -- is used for all discrete types and for fixed-point types. + + procedure Build_And_Analyze_Renamed_Body + (Decl : Node_Id; + New_S : Entity_Id; + After : in out Node_Id); + -- Build body for a renaming declaration, insert in tree and analyze. + + procedure Check_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_Fixed_Point_Type (Typ : Entity_Id); + -- Freeze fixed point type. For fixed-point types, we have to defer + -- setting the size and bounds till the freeze point, since they are + -- potentially affected by the presence of size and small clauses. + + 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, or has a full view. + + procedure Process_Default_Expressions + (E : Entity_Id; + After : in out Node_Id); + -- This procedure is called for each subprogram to complete processing + -- of default expressions at the point where all types are known to be + -- frozen. The expressions must be analyzed in full, to make sure that + -- all error processing is done (they have only been pre-analyzed). If + -- the expression is not an entity or literal, its analysis may generate + -- code which must not be executed. In that case we build a function + -- body to hold that code. This wrapper function serves no other purpose + -- (it used to be called to evaluate the default, but now the default is + -- inlined at each point of call). + + procedure Set_Component_Alignment_If_Not_Set (Typ : Entity_Id); + -- Typ is a record or array type that is being frozen. This routine + -- sets the default component alignment from the scope stack values + -- if the alignment is otherwise not specified. + + procedure Check_Debug_Info_Needed (T : Entity_Id); + -- As each entity is frozen, this routine is called to deal with the + -- setting of Debug_Info_Needed for the entity. This flag is set if + -- the entity comes from source, or if we are in Debug_Generated_Code + -- mode or if the -gnatdV debug flag is set. However, it never sets + -- the flag if Debug_Info_Off is set. + + procedure Set_Debug_Info_Needed (T : Entity_Id); + -- Sets the Debug_Info_Needed flag on entity T if not already set, and + -- also on any entities that are needed by T (for an object, the type + -- of the object is needed, and for a type, the subsidiary types are + -- needed -- see body for details). Never has any effect on T if the + -- Debug_Info_Off flag is set. + + ------------------------------- + -- Adjust_Esize_For_Alignment -- + ------------------------------- + + procedure Adjust_Esize_For_Alignment (Typ : Entity_Id) is + Align : Uint; + + begin + if Known_Esize (Typ) and then Known_Alignment (Typ) then + Align := Alignment_In_Bits (Typ); + + if Align > Esize (Typ) + and then Align <= Standard_Long_Long_Integer_Size + then + Set_Esize (Typ, Align); + end if; + end if; + end Adjust_Esize_For_Alignment; + + ------------------------------------ + -- Build_And_Analyze_Renamed_Body -- + ------------------------------------ + + procedure Build_And_Analyze_Renamed_Body + (Decl : Node_Id; + New_S : Entity_Id; + After : in out Node_Id) + is + Body_Node : constant Node_Id := Build_Renamed_Body (Decl, New_S); + + begin + Insert_After (After, Body_Node); + Mark_Rewrite_Insertion (Body_Node); + Analyze (Body_Node); + After := Body_Node; + end Build_And_Analyze_Renamed_Body; + + ------------------------ + -- Build_Renamed_Body -- + ------------------------ + + function Build_Renamed_Body + (Decl : Node_Id; + New_S : Entity_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (New_S); + -- We use for the source location of the renamed body, the location + -- of the spec entity. It might seem more natural to use the location + -- of the renaming declaration itself, but that would be wrong, since + -- then the body we create would look as though it was created far + -- too late, and this could cause problems with elaboration order + -- analysis, particularly in connection with instantiations. + + N : constant Node_Id := Unit_Declaration_Node (New_S); + Nam : constant Node_Id := Name (N); + Old_S : Entity_Id; + Spec : constant Node_Id := New_Copy_Tree (Specification (Decl)); + Actuals : List_Id := No_List; + Call_Node : Node_Id; + Call_Name : Node_Id; + Body_Node : Node_Id; + Formal : Entity_Id; + O_Formal : Entity_Id; + Param_Spec : Node_Id; + + begin + -- Determine the entity being renamed, which is the target of the + -- call statement. If the name is an explicit dereference, this is + -- a renaming of a subprogram type rather than a subprogram. The + -- name itself is fully analyzed. + + if Nkind (Nam) = N_Selected_Component then + Old_S := Entity (Selector_Name (Nam)); + + elsif Nkind (Nam) = N_Explicit_Dereference then + Old_S := Etype (Nam); + + elsif Nkind (Nam) = N_Indexed_Component then + + if Is_Entity_Name (Prefix (Nam)) then + Old_S := Entity (Prefix (Nam)); + else + Old_S := Entity (Selector_Name (Prefix (Nam))); + end if; + + elsif Nkind (Nam) = N_Character_Literal then + Old_S := Etype (New_S); + + else + Old_S := Entity (Nam); + end if; + + if Is_Entity_Name (Nam) then + Call_Name := New_Reference_To (Old_S, Loc); + else + Call_Name := New_Copy (Name (N)); + + -- The original name may have been overloaded, but + -- is fully resolved now. + + Set_Is_Overloaded (Call_Name, False); + end if; + + -- For simple renamings, subsequent calls can be expanded directly + -- as called to the renamed entity. The body must be generated in + -- any case for calls they may appear elsewhere. + + if (Ekind (Old_S) = E_Function + or else Ekind (Old_S) = E_Procedure) + and then Nkind (Decl) = N_Subprogram_Declaration + then + Set_Body_To_Inline (Decl, Old_S); + end if; + + -- The body generated for this renaming is an internal artifact, and + -- does not constitute a freeze point for the called entity. + + Set_Must_Not_Freeze (Call_Name); + + Formal := First_Formal (Defining_Entity (Decl)); + + if Present (Formal) then + Actuals := New_List; + + while Present (Formal) loop + Append (New_Reference_To (Formal, Loc), Actuals); + Next_Formal (Formal); + end loop; + end if; + + -- If the renamed entity is an entry, inherit its profile. For + -- other renamings as bodies, both profiles must be subtype + -- conformant, so it is not necessary to replace the profile given + -- in the declaration. However, default values that are aggregates + -- are rewritten when partially analyzed, so we recover the original + -- aggregate to insure that subsequent conformity checking works. + + 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 then + Set_Expression (Param_Spec, + New_Copy_Tree (Original_Node (Default_Value (O_Formal)))); + end if; + + Next_Formal (Formal); + Next_Formal (O_Formal); + Next (Param_Spec); + end loop; + end if; + + -- If the renamed entity is a function, the generated body contains a + -- return statement. Otherwise, build a procedure call. If the entity is + -- an entry, subsequent analysis of the call will transform it into the + -- proper entry or protected operation call. If the renamed entity is + -- a character literal, return it directly. + + if Ekind (Old_S) = E_Function + or else Ekind (Old_S) = E_Operator + or else (Ekind (Old_S) = E_Subprogram_Type + and then Etype (Old_S) /= Standard_Void_Type) + then + Call_Node := + Make_Return_Statement (Loc, + Expression => + Make_Function_Call (Loc, + Name => Call_Name, + Parameter_Associations => Actuals)); + + elsif Ekind (Old_S) = E_Enumeration_Literal then + Call_Node := + Make_Return_Statement (Loc, + Expression => New_Occurrence_Of (Old_S, Loc)); + + elsif Nkind (Nam) = N_Character_Literal then + Call_Node := + Make_Return_Statement (Loc, + Expression => Call_Name); + + else + Call_Node := + Make_Procedure_Call_Statement (Loc, + Name => Call_Name, + Parameter_Associations => Actuals); + end if; + + -- Create entities for subprogram body and formals. + + Set_Defining_Unit_Name (Spec, + Make_Defining_Identifier (Loc, Chars => Chars (New_S))); + + Param_Spec := First (Parameter_Specifications (Spec)); + + while Present (Param_Spec) loop + Set_Defining_Identifier (Param_Spec, + Make_Defining_Identifier (Loc, + Chars => Chars (Defining_Identifier (Param_Spec)))); + Next (Param_Spec); + end loop; + + Body_Node := + Make_Subprogram_Body (Loc, + Specification => Spec, + Declarations => New_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (Call_Node))); + + if Nkind (Decl) /= N_Subprogram_Declaration then + Rewrite (N, + Make_Subprogram_Declaration (Loc, + Specification => Specification (N))); + end if; + + -- Link the body to the entity whose declaration it completes. If + -- the body is analyzed when the renamed entity is frozen, it may be + -- necessary to restore the proper scope (see package Exp_Ch13). + + if Nkind (N) = N_Subprogram_Renaming_Declaration + and then Present (Corresponding_Spec (N)) + then + Set_Corresponding_Spec (Body_Node, Corresponding_Spec (N)); + else + Set_Corresponding_Spec (Body_Node, New_S); + end if; + + return Body_Node; + end Build_Renamed_Body; + + ----------------------------- + -- Check_Compile_Time_Size -- + ----------------------------- + + procedure Check_Compile_Time_Size (T : Entity_Id) is + + procedure Set_Small_Size (S : Uint); + -- Sets the compile time known size (32 bits or less) in the Esize + -- field, checking for a size clause that was given which attempts + -- to give a smaller size. + + function Size_Known (T : Entity_Id) return Boolean; + -- Recursive function that does all the work. + -- Is this right??? isn't recursive case already handled??? + -- certainly yes for normal call, but what about bogus sem_res call??? + + function Static_Discriminated_Components (T : Entity_Id) return Boolean; + -- If T is a constrained subtype, its size is not known if any of its + -- discriminant constraints is not static and it is not a null record. + -- The test is conservative and doesn't check that the components are + -- in fact constrained by non-static discriminant values. Could be made + -- more precise ??? + + -------------------- + -- Set_Small_Size -- + -------------------- + + procedure Set_Small_Size (S : Uint) is + begin + if S > 32 then + return; + + elsif Has_Size_Clause (T) then + if RM_Size (T) < S then + Error_Msg_Uint_1 := S; + Error_Msg_NE + ("size for & is too small, minimum is ^", + Size_Clause (T), T); + + elsif Unknown_Esize (T) then + Set_Esize (T, S); + end if; + + -- Set sizes if not set already + + else + if Unknown_Esize (T) then + Set_Esize (T, S); + end if; + + if Unknown_RM_Size (T) then + Set_RM_Size (T, S); + end if; + end if; + end Set_Small_Size; + + ---------------- + -- Size_Known -- + ---------------- + + function Size_Known (T : Entity_Id) return Boolean is + Index : Entity_Id; + Comp : Entity_Id; + Ctyp : Entity_Id; + Low : Node_Id; + High : Node_Id; + + begin + if Size_Known_At_Compile_Time (T) then + return True; + + elsif Error_Posted (T) then + return False; + + elsif Is_Scalar_Type (T) + or else Is_Task_Type (T) + then + return not Is_Generic_Type (T); + + elsif Is_Array_Type (T) then + + if Ekind (T) = E_String_Literal_Subtype then + Set_Small_Size (Component_Size (T) * String_Literal_Length (T)); + return True; + + elsif not Is_Constrained (T) then + return False; + + elsif not Size_Known (Component_Type (T)) then + return False; + end if; + + -- Check for all indexes static, and also compute possible + -- size (in case it is less than 32 and may be packable). + + declare + Esiz : Uint := Component_Size (T); + Dim : Uint; + + begin + Index := First_Index (T); + + while Present (Index) loop + if Nkind (Index) = N_Range then + Get_Index_Bounds (Index, Low, High); + + elsif Error_Posted (Scalar_Range (Etype (Index))) then + return False; + + else + Low := Type_Low_Bound (Etype (Index)); + High := Type_High_Bound (Etype (Index)); + end if; + + if not Compile_Time_Known_Value (Low) + or else not Compile_Time_Known_Value (High) + or else Etype (Index) = Any_Type + then + return False; + + else + Dim := Expr_Value (High) - Expr_Value (Low) + 1; + + if Dim >= 0 then + Esiz := Esiz * Dim; + else + Esiz := Uint_0; + end if; + end if; + + Next_Index (Index); + end loop; + + Set_Small_Size (Esiz); + return True; + end; + + elsif Is_Access_Type (T) then + return True; + + elsif Is_Private_Type (T) + and then not Is_Generic_Type (T) + and then Present (Underlying_Type (T)) + then + return Size_Known (Underlying_Type (T)); + + elsif Is_Record_Type (T) then + if Is_Class_Wide_Type (T) then + return False; + + elsif T /= Base_Type (T) then + return Size_Known_At_Compile_Time (Base_Type (T)) + and then Static_Discriminated_Components (T); + + else + declare + Packed_Size_Known : Boolean := Is_Packed (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; + else + -- We do not know the packed size, it is too much + -- trouble to figure it out. + + Packed_Size_Known := False; + end if; + end if; + + Comp := First_Entity (T); + + while Present (Comp) loop + if Ekind (Comp) = E_Component + or else + Ekind (Comp) = E_Discriminant + then + Ctyp := Etype (Comp); + + if Present (Component_Clause (Comp)) then + Packed_Size_Known := False; + end if; + + if not Size_Known (Ctyp) then + return False; + + elsif Packed_Size_Known 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; + end if; + + Packed_Size := + Packed_Size + RM_Size (Ctyp); + + -- 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; + end if; + end if; + + Next_Entity (Comp); + end loop; + + if Packed_Size_Known then + Set_Small_Size (Packed_Size); + end if; + + return True; + end; + end if; + + else + return False; + end if; + end Size_Known; + + ------------------------------------- + -- Static_Discriminated_Components -- + ------------------------------------- + + function Static_Discriminated_Components + (T : Entity_Id) + return Boolean + is + Constraint : Elmt_Id; + + begin + if Has_Discriminants (T) + and then Present (Discriminant_Constraint (T)) + and then Present (First_Component (T)) + then + Constraint := First_Elmt (Discriminant_Constraint (T)); + + while Present (Constraint) loop + if not Compile_Time_Known_Value (Node (Constraint)) then + return False; + end if; + + Next_Elmt (Constraint); + end loop; + end if; + + return True; + end Static_Discriminated_Components; + + -- Start of processing for Check_Compile_Time_Size + + begin + Set_Size_Known_At_Compile_Time (T, Size_Known (T)); + end Check_Compile_Time_Size; + + ----------------------------- + -- Check_Debug_Info_Needed -- + ----------------------------- + + procedure Check_Debug_Info_Needed (T : Entity_Id) is + begin + if Needs_Debug_Info (T) or else Debug_Info_Off (T) then + return; + + elsif Comes_From_Source (T) + or else Debug_Generated_Code + or else Debug_Flag_VV + then + Set_Debug_Info_Needed (T); + end if; + end Check_Debug_Info_Needed; + + ---------------------------- + -- Check_Strict_Alignment -- + ---------------------------- + + procedure Check_Strict_Alignment (E : Entity_Id) is + Comp : Entity_Id; + + begin + if Is_Tagged_Type (E) or else Is_Concurrent_Type (E) then + Set_Strict_Alignment (E); + + elsif Is_Array_Type (E) then + Set_Strict_Alignment (E, Strict_Alignment (Component_Type (E))); + + elsif Is_Record_Type (E) then + if Is_Limited_Record (E) then + Set_Strict_Alignment (E); + return; + end if; + + Comp := First_Component (E); + + while Present (Comp) loop + if not Is_Type (Comp) + and then (Strict_Alignment (Etype (Comp)) + or else Is_Aliased (Comp)) + then + Set_Strict_Alignment (E); + return; + end if; + + Next_Component (Comp); + end loop; + end if; + end Check_Strict_Alignment; + + ------------------------- + -- Check_Unsigned_Type -- + ------------------------- + + procedure Check_Unsigned_Type (E : Entity_Id) is + Ancestor : Entity_Id; + Lo_Bound : Node_Id; + Btyp : Entity_Id; + + begin + if not Is_Discrete_Or_Fixed_Point_Type (E) then + return; + end if; + + -- Do not attempt to analyze case where range was in error + + if Error_Posted (Scalar_Range (E)) then + return; + end if; + + -- The situation that is non trivial is something like + + -- subtype x1 is integer range -10 .. +10; + -- subtype x2 is x1 range 0 .. V1; + -- subtype x3 is x2 range V2 .. V3; + -- subtype x4 is x3 range V4 .. V5; + + -- where Vn are variables. Here the base type is signed, but we still + -- know that x4 is unsigned because of the lower bound of x2. + + -- The only way to deal with this is to look up the ancestor chain + + Ancestor := E; + loop + if Ancestor = Any_Type or else Etype (Ancestor) = Any_Type then + return; + end if; + + Lo_Bound := Type_Low_Bound (Ancestor); + + if Compile_Time_Known_Value (Lo_Bound) then + + if Expr_Rep_Value (Lo_Bound) >= 0 then + Set_Is_Unsigned_Type (E, True); + end if; + + return; + + else + Ancestor := Ancestor_Subtype (Ancestor); + + -- If no ancestor had a static lower bound, go to base type + + if No (Ancestor) then + + -- Note: the reason we still check for a compile time known + -- value for the base type is that at least in the case of + -- generic formals, we can have bounds that fail this test, + -- and there may be other cases in error situations. + + Btyp := Base_Type (E); + + if Btyp = Any_Type or else Etype (Btyp) = Any_Type then + return; + end if; + + Lo_Bound := Type_Low_Bound (Base_Type (E)); + + if Compile_Time_Known_Value (Lo_Bound) + and then Expr_Rep_Value (Lo_Bound) >= 0 + then + Set_Is_Unsigned_Type (E, True); + end if; + + return; + + end if; + end if; + end loop; + end Check_Unsigned_Type; + + ---------------- + -- 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). + + 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. + + 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; + + begin + E := From; + while Present (E) loop + + -- If the entity is an inner package which is not a package + -- renaming, then its entities must be frozen at this point. + -- Note that such entities do NOT get frozen at the end of + -- the nested package itself (only library packages freeze). + + -- Same is true for task declarations, where anonymous records + -- created for entry parameters must be frozen. + + if Ekind (E) = E_Package + and then No (Renamed_Object (E)) + and then not Is_Child_Unit (E) + and then not Is_Frozen (E) + then + New_Scope (E); + Install_Visible_Declarations (E); + Install_Private_Declarations (E); + + Freeze_All (First_Entity (E), After); + + End_Package_Scope (E); + + elsif Ekind (E) in Task_Kind + and then + (Nkind (Parent (E)) = N_Task_Type_Declaration + or else + Nkind (Parent (E)) = N_Single_Task_Declaration) + then + New_Scope (E); + Freeze_All (First_Entity (E), After); + End_Scope; + + -- For a derived tagged type, we must ensure that all the + -- primitive operations of the parent have been frozen, so + -- that their addresses will be in the parent's dispatch table + -- at the point it is inherited. + + elsif Ekind (E) = E_Record_Type + and then Is_Tagged_Type (E) + and then Is_Tagged_Type (Etype (E)) + and then Is_Derived_Type (E) + then + declare + Prim_List : constant Elist_Id := + Primitive_Operations (Etype (E)); + Prim : Elmt_Id; + Subp : Entity_Id; + + begin + Prim := First_Elmt (Prim_List); + + while Present (Prim) loop + Subp := Node (Prim); + + if Comes_From_Source (Subp) + and then not Is_Frozen (Subp) + then + Flist := Freeze_Entity (Subp, Loc); + Process_Flist; + end if; + + Next_Elmt (Prim); + end loop; + end; + end if; + + if not Is_Frozen (E) then + Flist := Freeze_Entity (E, Loc); + Process_Flist; + end if; + + Next_Entity (E); + end loop; + end Freeze_All_Ent; + + -- Start of processing for Freeze_All + + begin + Freeze_All_Ent (From, After); + + -- Now that all types are frozen, we can deal with default expressions + -- that require us to build a default expression functions. This is the + -- point at which such functions are constructed (after all types that + -- might be used in such expressions have been frozen). + -- We also add finalization chains to access types whose designated + -- types are controlled. This is normally done when freezing the type, + -- but this misses recursive type definitions where the later members + -- of the recursion introduce controlled components (e.g. 5624-001). + + -- Loop through entities + + E := From; + while Present (E) loop + + if Is_Subprogram (E) then + + if not Default_Expressions_Processed (E) then + Process_Default_Expressions (E, After); + end if; + + if not Has_Completion (E) then + Decl := Unit_Declaration_Node (E); + + if Nkind (Decl) = N_Subprogram_Renaming_Declaration then + Build_And_Analyze_Renamed_Body (Decl, E, After); + + elsif Nkind (Decl) = N_Subprogram_Declaration + and then Present (Corresponding_Body (Decl)) + and then + Nkind (Unit_Declaration_Node (Corresponding_Body (Decl))) + = N_Subprogram_Renaming_Declaration + then + Build_And_Analyze_Renamed_Body + (Decl, Corresponding_Body (Decl), After); + end if; + end if; + + elsif Ekind (E) in Task_Kind + and then + (Nkind (Parent (E)) = N_Task_Type_Declaration + or else + Nkind (Parent (E)) = N_Single_Task_Declaration) + then + declare + Ent : Entity_Id; + + begin + Ent := First_Entity (E); + + while Present (Ent) loop + + if Is_Entry (Ent) + and then not Default_Expressions_Processed (Ent) + then + Process_Default_Expressions (Ent, After); + end if; + + Next_Entity (Ent); + end loop; + end; + + elsif Is_Access_Type (E) + and then Comes_From_Source (E) + and then Ekind (Directly_Designated_Type (E)) = E_Incomplete_Type + and then Controlled_Type (Designated_Type (E)) + and then No (Associated_Final_Chain (E)) + then + Build_Final_List (Parent (E), E); + end if; + + Next_Entity (E); + end loop; + + end Freeze_All; + + ----------------------- + -- Freeze_And_Append -- + ----------------------- + + procedure Freeze_And_Append + (Ent : Entity_Id; + Loc : Source_Ptr; + Result : in out List_Id) + is + L : constant List_Id := Freeze_Entity (Ent, Loc); + + begin + if Is_Non_Empty_List (L) then + if Result = No_List then + Result := L; + else + Append_List (L, Result); + end if; + end if; + end Freeze_And_Append; + + ------------------- + -- Freeze_Before -- + ------------------- + + procedure Freeze_Before (N : Node_Id; T : Entity_Id) is + Freeze_Nodes : constant List_Id := Freeze_Entity (T, Sloc (N)); + F : Node_Id; + + begin + if Is_Non_Empty_List (Freeze_Nodes) then + F := First (Freeze_Nodes); + + if Present (F) then + Insert_Actions (N, Freeze_Nodes); + end if; + end if; + end Freeze_Before; + + ------------------- + -- Freeze_Entity -- + ------------------- + + function Freeze_Entity (E : Entity_Id; Loc : Source_Ptr) return List_Id is + Comp : Entity_Id; + F_Node : Node_Id; + Result : List_Id; + Indx : Node_Id; + Formal : Entity_Id; + Atype : Entity_Id; + + procedure Check_Current_Instance (Comp_Decl : Node_Id); + -- Check that an Access or Unchecked_Access attribute with + -- a prefix which is the current instance type can only be + -- applied when the type is limited. + + function After_Last_Declaration return Boolean; + -- If Loc is a freeze_entity that appears after the last declaration + -- in the scope, inhibit error messages on late completion. + + procedure Freeze_Record_Type (Rec : Entity_Id); + -- Freeze each component, handle some representation clauses, and + -- freeze primitive operations if this is a tagged type. + + ---------------------------- + -- After_Last_Declaration -- + ---------------------------- + + function After_Last_Declaration return Boolean is + Spec : Node_Id := Parent (Current_Scope); + + begin + if Nkind (Spec) = N_Package_Specification then + if Present (Private_Declarations (Spec)) then + return Loc >= Sloc (Last (Private_Declarations (Spec))); + + elsif Present (Visible_Declarations (Spec)) then + return Loc >= Sloc (Last (Visible_Declarations (Spec))); + else + return False; + end if; + + else + return False; + end if; + end After_Last_Declaration; + + ---------------------------- + -- Check_Current_Instance -- + ---------------------------- + + procedure Check_Current_Instance (Comp_Decl : Node_Id) is + + function Process (N : Node_Id) return Traverse_Result; + -- Process routine to apply check to given node. + + function Process (N : Node_Id) return Traverse_Result is + begin + case Nkind (N) is + when N_Attribute_Reference => + if (Attribute_Name (N) = Name_Access + or else + Attribute_Name (N) = Name_Unchecked_Access) + and then Is_Entity_Name (Prefix (N)) + and then Is_Type (Entity (Prefix (N))) + and then Entity (Prefix (N)) = E + then + Error_Msg_N + ("current instance must be a limited type", Prefix (N)); + return Abandon; + else + return OK; + end if; + + when others => return OK; + end case; + end Process; + + procedure Traverse is new Traverse_Proc (Process); + + -- Start of processing for Check_Current_Instance + + begin + Traverse (Comp_Decl); + end Check_Current_Instance; + + ------------------------ + -- Freeze_Record_Type -- + ------------------------ + + procedure Freeze_Record_Type (Rec : Entity_Id) is + Comp : Entity_Id; + Junk : Boolean; + ADC : Node_Id; + + Unplaced_Component : Boolean := False; + -- Set True if we find at least one component with no component + -- clause (used to warn about useless Pack pragmas). + + Placed_Component : Boolean := False; + -- Set True if we find at least one component with a component + -- clause (used to warn about useless Bit_Order pragmas). + + begin + -- Freeze components and embedded subtypes + + Comp := First_Entity (Rec); + + while Present (Comp) loop + + if not Is_Type (Comp) then + Freeze_And_Append (Etype (Comp), Loc, Result); + end if; + + -- If the component is an access type with an allocator + -- as default value, the designated type will be frozen + -- by the corresponding expression in init_proc. In order + -- to place the freeze node for the designated type before + -- that for the current record type, freeze it now. + + -- Same process if the component is an array of access types, + -- initialized with an aggregate. If the designated type is + -- private, it cannot contain allocators, and it is premature + -- to freeze the type, so we check for this as well. + + if Is_Access_Type (Etype (Comp)) + and then Present (Parent (Comp)) + and then Present (Expression (Parent (Comp))) + and then Nkind (Expression (Parent (Comp))) = N_Allocator + then + declare + Alloc : constant Node_Id := Expression (Parent (Comp)); + + begin + -- If component is pointer to a classwide type, freeze + -- the specific type in the expression being allocated. + -- The expression may be a subtype indication, in which + -- case freeze the subtype mark. + + if Is_Class_Wide_Type (Designated_Type (Etype (Comp))) then + + if Is_Entity_Name (Expression (Alloc)) then + Freeze_And_Append + (Entity (Expression (Alloc)), Loc, Result); + elsif + Nkind (Expression (Alloc)) = N_Subtype_Indication + then + Freeze_And_Append + (Entity (Subtype_Mark (Expression (Alloc))), + Loc, Result); + end if; + else + Freeze_And_Append + (Designated_Type (Etype (Comp)), Loc, Result); + end if; + end; + + elsif Is_Array_Type (Etype (Comp)) + and then Is_Access_Type (Component_Type (Etype (Comp))) + and then Present (Parent (Comp)) + and then Nkind (Parent (Comp)) = N_Component_Declaration + and then Present (Expression (Parent (Comp))) + and then Nkind (Expression (Parent (Comp))) = N_Aggregate + and then Is_Fully_Defined + (Designated_Type (Component_Type (Etype (Comp)))) + then + Freeze_And_Append + (Designated_Type + (Component_Type (Etype (Comp))), Loc, Result); + end if; + + -- Processing for real components (exclude anonymous subtypes) + + if Ekind (Comp) = E_Component + or else Ekind (Comp) = E_Discriminant + then + -- Check for error of component clause given for variable + -- sized type. We have to delay this test till this point, + -- since the component type has to be frozen for us to know + -- if it is variable length. We omit this test in a generic + -- context, it will be applied at instantiation time. + + declare + CC : constant Node_Id := Component_Clause (Comp); + + begin + if Present (CC) then + Placed_Component := True; + + if not Size_Known_At_Compile_Time + (Underlying_Type (Etype (Comp))) + and then not Inside_A_Generic + then + Error_Msg_N + ("component clause not allowed for variable " & + "length component", CC); + end if; + + else + Unplaced_Component := True; + end if; + end; + + -- If component clause is present, then deal with the + -- non-default bit order case. We cannot do this before + -- the freeze point, because there is no required order + -- for the component clause and the bit_order clause. + + -- We only do this processing for the base type, and in + -- fact that's important, since otherwise if there are + -- record subtypes, we could reverse the bits once for + -- each subtype, which would be incorrect. + + if Present (Component_Clause (Comp)) + and then Reverse_Bit_Order (Rec) + and then Ekind (E) = E_Record_Type + then + declare + CFB : constant Uint := Component_Bit_Offset (Comp); + CSZ : constant Uint := Esize (Comp); + CLC : constant Node_Id := Component_Clause (Comp); + Pos : constant Node_Id := Position (CLC); + FB : constant Node_Id := First_Bit (CLC); + + Storage_Unit_Offset : constant Uint := + CFB / System_Storage_Unit; + + Start_Bit : constant Uint := + CFB mod System_Storage_Unit; + + begin + -- Cases where field goes over storage unit boundary + + if Start_Bit + CSZ > System_Storage_Unit then + + -- Allow multi-byte field but generate warning + + if Start_Bit mod System_Storage_Unit = 0 + and then CSZ mod System_Storage_Unit = 0 + then + Error_Msg_N + ("multi-byte field specified with non-standard" + & " Bit_Order?", CLC); + + if Bytes_Big_Endian then + Error_Msg_N + ("bytes are not reversed " + & "(component is big-endian)?", CLC); + else + Error_Msg_N + ("bytes are not reversed " + & "(component is little-endian)?", CLC); + end if; + + -- Do not allow non-contiguous field + + else + Error_Msg_N + ("attempt to specify non-contiguous field" + & " not permitted", CLC); + Error_Msg_N + ("\(caused by non-standard Bit_Order " + & "specified)", CLC); + end if; + + -- Case where field fits in one storage unit + + else + -- Give warning if suspicious component clause + + if Intval (FB) >= System_Storage_Unit then + Error_Msg_N + ("?Bit_Order clause does not affect " & + "byte ordering", Pos); + Error_Msg_Uint_1 := + Intval (Pos) + Intval (FB) / System_Storage_Unit; + Error_Msg_N + ("?position normalized to ^ before bit " & + "order interpreted", Pos); + end if; + + -- Here is where we fix up the Component_Bit_Offset + -- value to account for the reverse bit order. + -- Some examples of what needs to be done are: + + -- First_Bit .. Last_Bit Component_Bit_Offset + -- old new old new + + -- 0 .. 0 7 .. 7 0 7 + -- 0 .. 1 6 .. 7 0 6 + -- 0 .. 2 5 .. 7 0 5 + -- 0 .. 7 0 .. 7 0 4 + + -- 1 .. 1 6 .. 6 1 6 + -- 1 .. 4 3 .. 6 1 3 + -- 4 .. 7 0 .. 3 4 0 + + -- The general rule is that the first bit is + -- is obtained by subtracting the old ending bit + -- from storage_unit - 1. + + Set_Component_Bit_Offset (Comp, + (Storage_Unit_Offset * System_Storage_Unit) + + (System_Storage_Unit - 1) + - (Start_Bit + CSZ - 1)); + + Set_Normalized_First_Bit (Comp, + Component_Bit_Offset (Comp) mod System_Storage_Unit); + end if; + end; + end if; + end if; + + Next_Entity (Comp); + end loop; + + -- Check for useless pragma Bit_Order + + if not Placed_Component and then Reverse_Bit_Order (Rec) then + ADC := Get_Attribute_Definition_Clause (Rec, Attribute_Bit_Order); + Error_Msg_N ("?Bit_Order specification has no effect", ADC); + Error_Msg_N ("\?since no component clauses were specified", ADC); + end if; + + -- Check for useless pragma Pack when all components placed + + if Is_Packed (Rec) + and then not Unplaced_Component + and then Warn_On_Redundant_Constructs + then + Error_Msg_N + ("?pragma Pack has no effect, no unplaced components", + Get_Rep_Pragma (Rec, Name_Pack)); + Set_Is_Packed (Rec, False); + end if; + + -- If this is the record corresponding to a remote type, + -- freeze the remote type here since that is what we are + -- semantically freeing. This prevents having the freeze node + -- for that type in an inner scope. + + -- Also, Check for controlled components and unchecked unions. + -- Finally, enforce the restriction that access attributes with + -- a current instance prefix can only apply to limited types. + + if Ekind (Rec) = E_Record_Type then + + if Present (Corresponding_Remote_Type (Rec)) then + Freeze_And_Append + (Corresponding_Remote_Type (Rec), Loc, Result); + end if; + + Comp := First_Component (Rec); + + while Present (Comp) loop + if Has_Controlled_Component (Etype (Comp)) + or else (Chars (Comp) /= Name_uParent + and then Is_Controlled (Etype (Comp))) + or else (Is_Protected_Type (Etype (Comp)) + and then Present + (Corresponding_Record_Type (Etype (Comp))) + and then Has_Controlled_Component + (Corresponding_Record_Type (Etype (Comp)))) + then + Set_Has_Controlled_Component (Rec); + exit; + end if; + + if Has_Unchecked_Union (Etype (Comp)) then + Set_Has_Unchecked_Union (Rec); + end if; + + if Has_Per_Object_Constraint (Comp) + and then not Is_Limited_Type (Rec) + then + -- Scan component declaration for likely misuses of + -- current instance, either in a constraint or in a + -- default expression. + + Check_Current_Instance (Parent (Comp)); + end if; + + Next_Component (Comp); + end loop; + end if; + + Set_Component_Alignment_If_Not_Set (Rec); + + -- For first subtypes, check if there are any fixed-point + -- fields with component clauses, where we must check the size. + -- This is not done till the freeze point, since for fixed-point + -- types, we do not know the size until the type is frozen. + + 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)) + then + Check_Size + (Component_Clause (Comp), + Etype (Comp), + Esize (Comp), + Junk); + end if; + + Next_Component (Comp); + end loop; + end if; + end Freeze_Record_Type; + + -- Start of processing for Freeze_Entity + + begin + -- Do not freeze if already frozen since we only need one freeze node. + + if Is_Frozen (E) then + return No_List; + + -- It is improper to freeze an external entity within a generic + -- because its freeze node will appear in a non-valid context. + -- ??? We should probably freeze the entity at that point and insert + -- the freeze node in a proper place but this proper place is not + -- easy to find, and the proper scope is not easy to restore. For + -- now, just wait to get out of the generic to freeze ??? + + elsif Inside_A_Generic and then External_Ref_In_Generic (E) then + return No_List; + + -- Do not freeze a global entity within an inner scope created during + -- expansion. A call to subprogram E within some internal procedure + -- (a stream attribute for example) might require freezing E, but the + -- freeze node must appear in the same declarative part as E itself. + -- The two-pass elaboration mechanism in gigi guarantees that E will + -- be frozen before the inner call is elaborated. We exclude constants + -- from this test, because deferred constants may be frozen early, and + -- must be diagnosed (see e.g. 1522-005). If the enclosing subprogram + -- comes from source, or is a generic instance, then the freeze point + -- is the one mandated by the language. and we freze the entity. + + elsif In_Open_Scopes (Scope (E)) + and then Scope (E) /= Current_Scope + and then Ekind (E) /= E_Constant + then + declare + S : Entity_Id := Current_Scope; + + begin + while Present (S) loop + if Is_Overloadable (S) then + if Comes_From_Source (S) + or else Is_Generic_Instance (S) + then + exit; + else + return No_List; + end if; + end if; + + S := Scope (S); + end loop; + end; + end if; + + -- Here to freeze the entity + + Result := No_List; + Set_Is_Frozen (E); + + -- Case of entity being frozen is other than a type + + if not Is_Type (E) then + + -- If entity is exported or imported and does not have an external + -- name, now is the time to provide the appropriate default name. + -- Skip this if the entity is stubbed, since we don't need a name + -- for any stubbed routine. + + if (Is_Imported (E) or else Is_Exported (E)) + and then No (Interface_Name (E)) + and then Convention (E) /= Convention_Stubbed + then + Set_Encoded_Interface_Name + (E, Get_Default_External_Name (E)); + end if; + + -- For a subprogram, freeze all parameter types and also the return + -- type (RM 13.14(13)). However skip this for internal subprograms. + -- This is also the point where any extra formal parameters are + -- created since we now know whether the subprogram will use + -- a foreign convention. + + if Is_Subprogram (E) then + + if not Is_Internal (E) then + + declare + F_Type : Entity_Id; + + function Is_Fat_C_Ptr_Type (T : Entity_Id) return Boolean; + -- Determines if given type entity is a fat pointer type + -- used as an argument type or return type to a subprogram + -- with C or C++ convention set. + + -------------------------- + -- Is_Fat_C_Access_Type -- + -------------------------- + + function Is_Fat_C_Ptr_Type (T : Entity_Id) return Boolean is + begin + return (Convention (E) = Convention_C + or else + Convention (E) = Convention_CPP) + and then Is_Access_Type (T) + and then Esize (T) > Ttypes.System_Address_Size; + end Is_Fat_C_Ptr_Type; + + begin + -- Loop through formals + + Formal := First_Formal (E); + + while Present (Formal) loop + + F_Type := Etype (Formal); + Freeze_And_Append (F_Type, Loc, Result); + + if Is_Private_Type (F_Type) + and then Is_Private_Type (Base_Type (F_Type)) + and then No (Full_View (Base_Type (F_Type))) + and then not Is_Generic_Type (F_Type) + and then not Is_Derived_Type (F_Type) + then + -- If the type of a formal is incomplete, subprogram + -- is being frozen prematurely. Within an instance + -- (but not within a wrapper package) this is an + -- an artifact of our need to regard the end of an + -- instantiation as a freeze point. Otherwise it is + -- a definite error. + -- and then not Is_Wrapper_Package (Current_Scope) ??? + + if In_Instance then + Set_Is_Frozen (E, False); + return No_List; + + elsif not After_Last_Declaration then + Error_Msg_Node_1 := F_Type; + Error_Msg + ("type& must be fully defined before this point", + Loc); + end if; + end if; + + -- Check bad use of fat C pointer + + if Is_Fat_C_Ptr_Type (F_Type) then + Error_Msg_Qual_Level := 1; + Error_Msg_N + ("?type of & does not correspond to C pointer", + Formal); + Error_Msg_Qual_Level := 0; + end if; + + -- Check for unconstrained array in exported foreign + -- convention case. + + if Convention (E) in Foreign_Convention + and then not Is_Imported (E) + and then Is_Array_Type (F_Type) + and then not Is_Constrained (F_Type) + then + Error_Msg_Qual_Level := 1; + Error_Msg_N + ("?type of argument& is unconstrained array", + Formal); + Error_Msg_N + ("?foreign caller must pass bounds explicitly", + Formal); + Error_Msg_Qual_Level := 0; + end if; + + Next_Formal (Formal); + end loop; + + -- Check return type + + if Ekind (E) = E_Function then + Freeze_And_Append (Etype (E), Loc, Result); + + if Is_Fat_C_Ptr_Type (Etype (E)) then + Error_Msg_N + ("?return type of& does not correspond to C pointer", + E); + + elsif Is_Array_Type (Etype (E)) + and then not Is_Constrained (Etype (E)) + and then not Is_Imported (E) + and then Convention (E) in Foreign_Convention + then + Error_Msg_N + ("foreign convention function may not " & + "return unconstrained array", E); + end if; + end if; + end; + end if; + + -- Must freeze its parent first if it is a derived subprogram + + if Present (Alias (E)) then + Freeze_And_Append (Alias (E), Loc, Result); + end if; + + -- If the return type requires a transient scope, and we are on + -- a target allowing functions to return with a depressed stack + -- pointer, then we mark the function as requiring this treatment. + + if Ekind (E) = E_Function + and then Functions_Return_By_DSP_On_Target + and then Requires_Transient_Scope (Etype (E)) + then + Set_Function_Returns_With_DSP (E); + end if; + + if not Is_Internal (E) then + Freeze_Subprogram (E); + end if; + + -- Here for other than a subprogram or type + + else + -- If entity has a type, and it is not a generic unit, then + -- freeze it first (RM 13.14(10)) + + if Present (Etype (E)) + and then Ekind (E) /= E_Generic_Function + then + Freeze_And_Append (Etype (E), Loc, Result); + end if; + + -- For object created by object declaration, perform required + -- categorization (preelaborate and pure) checks. Defer these + -- checks to freeze time since pragma Import inhibits default + -- initialization and thus pragma Import affects these checks. + + if Nkind (Declaration_Node (E)) = N_Object_Declaration then + Validate_Object_Declaration (Declaration_Node (E)); + end if; + + -- Check that a constant which has a pragma Volatile[_Components] + -- or Atomic[_Components] also has a pragma Import (RM C.6(13)) + + -- Note: Atomic[_Components] also sets Volatile[_Components] + + if Ekind (E) = E_Constant + and then (Has_Volatile_Components (E) or else Is_Volatile (E)) + and then not Is_Imported (E) + then + -- Make sure we actually have a pragma, and have not merely + -- inherited the indication from elsewhere (e.g. an address + -- clause, which is not good enough in RM terms!) + + if Present (Get_Rep_Pragma (E, Name_Atomic)) or else + Present (Get_Rep_Pragma (E, Name_Atomic_Components)) or else + Present (Get_Rep_Pragma (E, Name_Volatile)) or else + Present (Get_Rep_Pragma (E, Name_Volatile_Components)) + then + Error_Msg_N + ("stand alone atomic/volatile constant must be imported", + E); + end if; + end if; + + -- Static objects require special handling + + if (Ekind (E) = E_Constant or else Ekind (E) = E_Variable) + and then Is_Statically_Allocated (E) + then + Freeze_Static_Object (E); + end if; + + -- Remaining step is to layout objects + + if Ekind (E) = E_Variable + or else + Ekind (E) = E_Constant + or else + Ekind (E) = E_Loop_Parameter + or else + Is_Formal (E) + then + Layout_Object (E); + end if; + end if; + + -- Case of a type or subtype being frozen + + else + -- The type may be defined in a generic unit. This can occur when + -- freezing a generic function that returns the type (which is + -- defined in a parent unit). It is clearly meaningless to freeze + -- this type. However, if it is a subtype, its size may be determi- + -- nable and used in subsequent checks, so might as well try to + -- compute it. + + if Present (Scope (E)) + and then Is_Generic_Unit (Scope (E)) + then + Check_Compile_Time_Size (E); + return No_List; + end if; + + -- Deal with special cases of freezing for subtype + + if E /= Base_Type (E) then + + -- If ancestor subtype present, freeze that first. + -- Note that this will also get the base type frozen. + + Atype := Ancestor_Subtype (E); + + if Present (Atype) then + Freeze_And_Append (Atype, Loc, Result); + + -- Otherwise freeze the base type of the entity before + -- freezing the entity itself, (RM 13.14(14)). + + 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(14)) + + 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(14)). + + 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; + + -- For base type, propagate flags for component type + + if Ekind (E) = E_Array_Type then + 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; + end if; + + -- If packing was requested or if the component size was set + -- explicitly, then see if bit packing is required. This + -- processing is only done for base types, since all the + -- representation aspects involved are type-related. This + -- is not just an optimization, if we start processing the + -- subtypes, they intefere with the settings on the base + -- type (this is because Is_Packed has a slightly different + -- meaning before and after freezing). + + if E = Base_Type (E) then + declare + Csiz : Uint; + Esiz : Uint; + + begin + if (Is_Packed (E) or else Has_Pragma_Pack (E)) + and then not Has_Atomic_Components (E) + and then Known_Static_RM_Size (Ctyp) + then + Csiz := UI_Max (RM_Size (Ctyp), 1); + + elsif Known_Component_Size (E) then + Csiz := Component_Size (E); + + elsif not Known_Static_Esize (Ctyp) then + Csiz := Uint_0; + + else + Esiz := Esize (Ctyp); + + -- We can set the component size if it is less than + -- 16, rounding it up to the next storage unit size. + + if Esiz <= 8 then + Csiz := Uint_8; + elsif Esiz <= 16 then + Csiz := Uint_16; + else + Csiz := Uint_0; + end if; + + -- Set component size up to match alignment if + -- it would otherwise be less than the alignment. + -- This deals with cases of types whose alignment + -- exceeds their sizes (padded types). + + if Csiz /= 0 then + declare + A : constant Uint := Alignment_In_Bits (Ctyp); + + begin + if Csiz < A then + Csiz := A; + end if; + end; + end if; + + end if; + + if 1 <= Csiz and then Csiz <= 64 then + + -- We set the component size for all cases 1-64 + + Set_Component_Size (Base_Type (E), Csiz); + + -- Actual packing is not needed for 8,16,32,64 + -- Also not needed for 24 if alignment is 1 + + if Csiz = 8 + or else Csiz = 16 + or else Csiz = 32 + or else Csiz = 64 + or else (Csiz = 24 and then Alignment (Ctyp) = 1) + then + -- Here the array was requested to be packed, but + -- the packing request had no effect, so Is_Packed + -- is reset. + + -- Note: semantically this means that we lose + -- track of the fact that a derived type inherited + -- a pack pragma that was non-effective, but that + -- seems fine. + + -- We regard a Pack pragma as a request to set a + -- representation characteristic, and this request + -- may be ignored. + + Set_Is_Packed (Base_Type (E), False); + + -- In all other cases, packing is indeed needed + + else + Set_Has_Non_Standard_Rep (Base_Type (E)); + Set_Is_Bit_Packed_Array (Base_Type (E)); + Set_Is_Packed (Base_Type (E)); + end if; + end if; + end; + 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; + end; + + Set_Component_Alignment_If_Not_Set (E); + + -- If the array is packed, we must create the packed array + -- type to be used to actually implement the type. This is + -- only needed for real array types (not for string literal + -- types, since they are present only for the front end). + + if Is_Packed (E) + and then Ekind (E) /= E_String_Literal_Subtype + then + Create_Packed_Array_Type (E); + Freeze_And_Append (Packed_Array_Type (E), Loc, Result); + + -- Size information of packed array type is copied to the + -- array type, since this is really the representation. + + Set_Size_Info (E, Packed_Array_Type (E)); + Set_RM_Size (E, RM_Size (Packed_Array_Type (E))); + end if; + + -- For a class wide type, the corresponding specific type is + -- frozen as well (RM 13.14(14)) + + elsif Is_Class_Wide_Type (E) then + Freeze_And_Append (Root_Type (E), Loc, Result); + + -- If the Class_Wide_Type is an Itype (when type is the anonymous + -- parent of a derived type) and it is a library-level entity, + -- generate an itype reference for it. Otherwise, its first + -- explicit reference may be in an inner scope, which will be + -- rejected by the back-end. + + if Is_Itype (E) + and then Is_Compilation_Unit (Scope (E)) + then + + declare + Ref : 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; + + -- For record (sub)type, freeze all the component types (RM + -- 13.14(14). We test for E_Record_(sub)Type here, rather than + -- using Is_Record_Type, because we don't want to attempt the + -- freeze for the case of a private type with record extension + -- (we will do that later when the full type is frozen). + + elsif Ekind (E) = E_Record_Type + or else Ekind (E) = E_Record_Subtype + then + Freeze_Record_Type (E); + + -- For a concurrent type, freeze corresponding record type. This + -- does not correpond to any specific rule in the RM, but the + -- record type is essentially part of the concurrent type. + -- Freeze as well all local entities. This includes record types + -- created for entry parameter blocks, and whatever local entities + -- may appear in the private part. + + elsif Is_Concurrent_Type (E) then + if Present (Corresponding_Record_Type (E)) then + Freeze_And_Append + (Corresponding_Record_Type (E), Loc, Result); + end if; + + Comp := First_Entity (E); + + while Present (Comp) loop + if Is_Type (Comp) then + Freeze_And_Append (Comp, Loc, Result); + + elsif (Ekind (Comp)) /= E_Function then + Freeze_And_Append (Etype (Comp), Loc, Result); + end if; + + Next_Entity (Comp); + end loop; + + -- Private types are required to point to the same freeze node + -- as their corresponding full views. The freeze node itself + -- has to point to the partial view of the entity (because + -- from the partial view, we can retrieve the full view, but + -- not the reverse). However, in order to freeze correctly, + -- we need to freeze the full view. If we are freezing at the + -- end of a scope (or within the scope of the private type), + -- the partial and full views will have been swapped, the + -- full view appears first in the entity chain and the swapping + -- mechanism enusres that the pointers are properly set (on + -- scope exit). + + -- If we encounter the partial view before the full view + -- (e.g. when freezing from another scope), we freeze the + -- full view, and then set the pointers appropriately since + -- we cannot rely on swapping to fix things up (subtypes in an + -- outer scope might not get swapped). + + elsif Is_Incomplete_Or_Private_Type (E) + and then not Is_Generic_Type (E) + then + -- Case of full view present + + if Present (Full_View (E)) then + + -- If full view has already been frozen, then no + -- further processing is required + + if Is_Frozen (Full_View (E)) then + + Set_Has_Delayed_Freeze (E, False); + Set_Freeze_Node (E, Empty); + Check_Debug_Info_Needed (E); + + -- Otherwise freeze full view and patch the pointers + + else + if Is_Private_Type (Full_View (E)) + and then Present (Underlying_Full_View (Full_View (E))) + then + Freeze_And_Append + (Underlying_Full_View (Full_View (E)), Loc, Result); + end if; + + Freeze_And_Append (Full_View (E), Loc, Result); + + if Has_Delayed_Freeze (E) then + F_Node := Freeze_Node (Full_View (E)); + + 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; + + Check_Debug_Info_Needed (E); + end if; + + -- AI-117 requires that the convention of a partial view + -- be the same as the convention of the full view. Note + -- that this is a recognized breach of privacy, but it's + -- essential for logical consistency of representation, + -- and the lack of a rule in RM95 was an oversight. + + Set_Convention (E, Convention (Full_View (E))); + + Set_Size_Known_At_Compile_Time (E, + Size_Known_At_Compile_Time (Full_View (E))); + + -- Size information is copied from the full view to the + -- incomplete or private view for consistency + + -- We skip this is the full view is not a type. This is + -- very strange of course, and can only happen as a result + -- of certain illegalities, such as a premature attempt to + -- derive from an incomplete type. + + if Is_Type (Full_View (E)) then + Set_Size_Info (E, Full_View (E)); + Set_RM_Size (E, RM_Size (Full_View (E))); + end if; + + return Result; + + -- Case of no full view present. If entity is derived or subtype, + -- it is safe to freeze, correctness depends on the frozen status + -- of parent. Otherwise it is either premature usage, or a Taft + -- amendment type, so diagnosis is at the point of use and the + -- type might be frozen later. + + elsif E /= Base_Type (E) + or else Is_Derived_Type (E) + then + null; + + else + Set_Is_Frozen (E, False); + return No_List; + end if; + + -- For access subprogram, freeze types of all formals, the return + -- type was already frozen, since it is the Etype of the function. + + elsif Ekind (E) = E_Subprogram_Type then + Formal := First_Formal (E); + while Present (Formal) loop + Freeze_And_Append (Etype (Formal), Loc, Result); + Next_Formal (Formal); + end loop; + + -- If the return type requires a transient scope, and we are on + -- a target allowing functions to return with a depressed stack + -- pointer, then we mark the function as requiring this treatment. + + if Functions_Return_By_DSP_On_Target + and then Requires_Transient_Scope (Etype (E)) + then + Set_Function_Returns_With_DSP (E); + end if; + + Freeze_Subprogram (E); + + -- For access to a protected subprogram, freeze the equivalent + -- type (however this is not set if we are not generating code) + -- or if this is an anonymous type used just for resolution). + + elsif Ekind (E) = E_Access_Protected_Subprogram_Type + and then Operating_Mode = Generate_Code + and then Present (Equivalent_Type (E)) + then + Freeze_And_Append (Equivalent_Type (E), Loc, Result); + end if; + + -- Generic types are never seen by the back-end, and are also not + -- processed by the expander (since the expander is turned off for + -- generic processing), so we never need freeze nodes for them. + + if Is_Generic_Type (E) then + return Result; + end if; + + -- Some special processing for non-generic types to complete + -- representation details not known till the freeze point. + + if Is_Fixed_Point_Type (E) then + Freeze_Fixed_Point_Type (E); + + elsif Is_Enumeration_Type (E) then + Freeze_Enumeration_Type (E); + + elsif Is_Integer_Type (E) then + Adjust_Esize_For_Alignment (E); + + elsif Is_Access_Type (E) + and then No (Associated_Storage_Pool (E)) + then + Check_Restriction (No_Standard_Storage_Pools, E); + end if; + + -- If the current entity is an array or record subtype and has + -- discriminants used to constrain it, it must not freeze, because + -- Freeze_Entity nodes force Gigi to process the frozen type. + + if Is_Composite_Type (E) then + + if Is_Array_Type (E) then + + declare + Index : Node_Id := First_Index (E); + Expr1 : Node_Id; + Expr2 : Node_Id; + + begin + while Present (Index) loop + if Etype (Index) /= Any_Type then + Get_Index_Bounds (Index, Expr1, Expr2); + + for J in 1 .. 2 loop + if Nkind (Expr1) = N_Identifier + and then Ekind (Entity (Expr1)) = E_Discriminant + then + Set_Has_Delayed_Freeze (E, False); + Set_Freeze_Node (E, Empty); + Check_Debug_Info_Needed (E); + return Result; + end if; + + Expr1 := Expr2; + end loop; + end if; + + Next_Index (Index); + end loop; + end; + + elsif Has_Discriminants (E) + and Is_Constrained (E) + then + + declare + Constraint : Elmt_Id; + Expr : Node_Id; + begin + Constraint := First_Elmt (Discriminant_Constraint (E)); + + while Present (Constraint) loop + + Expr := Node (Constraint); + if Nkind (Expr) = N_Identifier + and then Ekind (Entity (Expr)) = E_Discriminant + then + Set_Has_Delayed_Freeze (E, False); + Set_Freeze_Node (E, Empty); + Check_Debug_Info_Needed (E); + return Result; + end if; + + Next_Elmt (Constraint); + end loop; + end; + + end if; + + -- AI-117 requires that all new primitives of a tagged type + -- must inherit the convention of the full view of the type. + -- Inherited and overriding operations are defined to inherit + -- the convention of their parent or overridden subprogram + -- (also specified in AI-117), and that will have occurred + -- earlier (in Derive_Subprogram and New_Overloaded_Entity). + -- Here we set the convention of primitives that are still + -- convention Ada, which will ensure that any new primitives + -- inherit the type's convention. Class-wide types can have + -- a foreign convention inherited from their specific type, + -- but are excluded from this since they don't have any + -- associated primitives. + + if Is_Tagged_Type (E) + and then not Is_Class_Wide_Type (E) + and then Convention (E) /= Convention_Ada + then + declare + Prim_List : constant Elist_Id := Primitive_Operations (E); + Prim : Elmt_Id := First_Elmt (Prim_List); + + begin + 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; + + -- Now that all types from which E may depend are frozen, see + -- if the size is known at compile time, if it must be unsigned, + -- or if strict alignent is required + + Check_Compile_Time_Size (E); + Check_Unsigned_Type (E); + + if Base_Type (E) = E then + Check_Strict_Alignment (E); + end if; + + -- Do not allow a size clause for a type which does not have a size + -- that is known at compile time + + if Has_Size_Clause (E) + and then not Size_Known_At_Compile_Time (E) + then + Error_Msg_N + ("size clause not allowed for variable length type", + Size_Clause (E)); + end if; + + -- Remaining process is to set/verify the representation information, + -- in particular the size and alignment values. This processing is + -- not required for generic types, since generic types do not play + -- any part in code generation, and so the size and alignment values + -- for suhc types are irrelevant. + + if Is_Generic_Type (E) then + return Result; + + -- Otherwise we call the layout procedure + + else + Layout_Type (E); + end if; + + -- End of freeze processing for type entities + end if; + + -- Here is where we logically freeze the current entity. If it has a + -- freeze node, then this is the point at which the freeze node is + -- linked into the result list. + + if Has_Delayed_Freeze (E) then + + -- If a freeze node is already allocated, use it, otherwise allocate + -- a new one. The preallocation happens in the case of anonymous base + -- types, where we preallocate so that we can set First_Subtype_Link. + -- Note that we reset the Sloc to the current freeze location. + + if Present (Freeze_Node (E)) then + F_Node := Freeze_Node (E); + Set_Sloc (F_Node, Loc); + + else + F_Node := New_Node (N_Freeze_Entity, Loc); + Set_Freeze_Node (E, F_Node); + Set_Access_Types_To_Process (F_Node, No_Elist); + Set_TSS_Elist (F_Node, No_Elist); + Set_Actions (F_Node, No_List); + end if; + + Set_Entity (F_Node, E); + + if Result = No_List then + Result := New_List (F_Node); + else + Append (F_Node, Result); + end if; + + end if; + + -- When a type is frozen, the first subtype of the type is frozen as + -- well (RM 13.14(15)). This has to be done after freezing the type, + -- since obviously the first subtype depends on its own base type. + + if Is_Type (E) then + Freeze_And_Append (First_Subtype (E), Loc, Result); + + -- If we just froze a tagged non-class wide record, then freeze the + -- corresponding class-wide type. This must be done after the tagged + -- type itself is frozen, because the class-wide type refers to the + -- tagged type which generates the class. + + if Is_Tagged_Type (E) + and then not Is_Class_Wide_Type (E) + and then Present (Class_Wide_Type (E)) + then + Freeze_And_Append (Class_Wide_Type (E), Loc, Result); + end if; + end if; + + Check_Debug_Info_Needed (E); + + -- Special handling for subprograms + + if Is_Subprogram (E) then + + -- If subprogram has address clause then reset Is_Public flag, since + -- we do not want the backend to generate external references. + + if Present (Address_Clause (E)) + and then not Is_Library_Level_Entity (E) + then + Set_Is_Public (E, False); + + -- If no address clause and not intrinsic, then for imported + -- subprogram in main unit, generate descriptor if we are in + -- Propagate_Exceptions mode. + + elsif Propagate_Exceptions + and then Is_Imported (E) + and then not Is_Intrinsic_Subprogram (E) + and then Convention (E) /= Convention_Stubbed + then + if Result = No_List then + Result := Empty_List; + end if; + + Generate_Subprogram_Descriptor_For_Imported_Subprogram + (E, Result); + end if; + + end if; + + return Result; + end Freeze_Entity; + + ----------------------------- + -- Freeze_Enumeration_Type -- + ----------------------------- + + procedure Freeze_Enumeration_Type (Typ : Entity_Id) is + begin + if Has_Foreign_Convention (Typ) + and then not Has_Size_Clause (Typ) + and then Esize (Typ) < Standard_Integer_Size + then + Init_Esize (Typ, Standard_Integer_Size); + + else + Adjust_Esize_For_Alignment (Typ); + end if; + end Freeze_Enumeration_Type; + + ----------------------- + -- Freeze_Expression -- + ----------------------- + + procedure Freeze_Expression (N : Node_Id) is + In_Def_Exp : constant Boolean := In_Default_Expression; + Typ : Entity_Id; + Nam : Entity_Id; + Desig_Typ : Entity_Id; + P : Node_Id; + Parent_P : Node_Id; + + Freeze_Outside : Boolean := False; + -- This flag is set true if the entity must be frozen outside the + -- current subprogram. This happens in the case of expander generated + -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do + -- not freeze all entities like other bodies, but which nevertheless + -- may reference entities that have to be frozen before the body and + -- obviously cannot be frozen inside the body. + + function In_Exp_Body (N : Node_Id) return Boolean; + -- Given an N_Handled_Sequence_Of_Statements node N, determines whether + -- it is the handled statement sequence of an expander generated + -- subprogram (init proc, or stream subprogram). If so, it returns + -- True, otherwise False. + + function In_Exp_Body (N : Node_Id) return Boolean is + P : Node_Id; + + begin + if Nkind (N) = N_Subprogram_Body then + P := N; + else + P := Parent (N); + end if; + + if Nkind (P) /= N_Subprogram_Body then + return False; + + else + P := Defining_Unit_Name (Specification (P)); + + if Nkind (P) = N_Defining_Identifier + and then (Chars (P) = Name_uInit_Proc or else + Chars (P) = Name_uInput or else + Chars (P) = Name_uOutput or else + Chars (P) = Name_uRead or else + Chars (P) = Name_uWrite) + then + return True; + else + return False; + end if; + end if; + + end In_Exp_Body; + + -- Start of processing for Freeze_Expression + + begin + -- Immediate return if freezing is inhibited. This flag is set by + -- the analyzer to stop freezing on generated expressions that would + -- cause freezing if they were in the source program, but which are + -- not supposed to freeze, since they are created. + + if Must_Not_Freeze (N) then + return; + end if; + + -- If expression is non-static, then it does not freeze in a default + -- expression, see section "Handling of Default Expressions" in the + -- spec of package Sem for further details. Note that we have to + -- make sure that we actually have a real expression (if we have + -- a subtype indication, we can't test Is_Static_Expression!) + + if In_Def_Exp + and then Nkind (N) in N_Subexpr + and then not Is_Static_Expression (N) + then + return; + end if; + + -- Freeze type of expression if not frozen already + + if Nkind (N) in N_Has_Etype + and then not Is_Frozen (Etype (N)) + then + Typ := Etype (N); + else + Typ := Empty; + end if; + + -- For entity name, freeze entity if not frozen already. A special + -- exception occurs for an identifier that did not come from source. + -- We don't let such identifiers freeze a non-internal entity, i.e. + -- an entity that did come from source, since such an identifier was + -- generated by the expander, and cannot have any semantic effect on + -- the freezing semantics. For example, this stops the parameter of + -- an initialization procedure from freezing the variable. + + if Is_Entity_Name (N) + and then not Is_Frozen (Entity (N)) + and then (Nkind (N) /= N_Identifier + or else Comes_From_Source (N) + or else not Comes_From_Source (Entity (N))) + then + Nam := Entity (N); + + else + Nam := Empty; + end if; + + -- For an allocator freeze designated type if not frozen already. + + -- For an aggregate whose component type is an access type, freeze + -- the designated type now, so that its freeze does not appear within + -- the loop that might be created in the expansion of the aggregate. + -- If the designated type is a private type without full view, the + -- expression cannot contain an allocator, so the type is not frozen. + + Desig_Typ := Empty; + case Nkind (N) is + + when N_Allocator => + Desig_Typ := Designated_Type (Etype (N)); + + when N_Aggregate => + if Is_Array_Type (Etype (N)) + and then Is_Access_Type (Component_Type (Etype (N))) + then + Desig_Typ := Designated_Type (Component_Type (Etype (N))); + end if; + + when N_Selected_Component | + N_Indexed_Component | + N_Slice => + + if Is_Access_Type (Etype (Prefix (N))) then + Desig_Typ := Designated_Type (Etype (Prefix (N))); + end if; + + when others => + null; + + end case; + + if Desig_Typ /= Empty + and then (Is_Frozen (Desig_Typ) + or else (not Is_Fully_Defined (Desig_Typ))) + then + Desig_Typ := Empty; + end if; + + -- All done if nothing needs freezing + + if No (Typ) + and then No (Nam) + and then No (Desig_Typ) + then + return; + end if; + + -- Loop for looking at the right place to insert the freeze nodes + -- exiting from the loop when it is appropriate to insert the freeze + -- node before the current node P. + + -- Also checks some special exceptions to the freezing rules. These + -- cases result in a direct return, bypassing the freeze action. + + P := N; + loop + Parent_P := Parent (P); + + -- If we don't have a parent, then we are not in a well-formed + -- tree. This is an unusual case, but there are some legitimate + -- situations in which this occurs, notably when the expressions + -- in the range of a type declaration are resolved. We simply + -- ignore the freeze request in this case. Is this right ??? + + if No (Parent_P) then + return; + end if; + + -- See if we have got to an appropriate point in the tree + + case Nkind (Parent_P) is + + -- A special test for the exception of (RM 13.14(8)) for the + -- case of per-object expressions (RM 3.8(18)) occurring in a + -- component definition or a discrete subtype definition. Note + -- that we test for a component declaration which includes both + -- cases we are interested in, and furthermore the tree does not + -- have explicit nodes for either of these two constructs. + + when N_Component_Declaration => + + -- The case we want to test for here is an identifier that is + -- a per-object expression, this is either a discriminant that + -- appears in a context other than the component declaration + -- or it is a reference to the type of the enclosing construct. + + -- For either of these cases, we skip the freezing + + if not In_Default_Expression + and then Nkind (N) = N_Identifier + and then (Present (Entity (N))) + then + -- We recognize the discriminant case by just looking for + -- a reference to a discriminant. It can only be one for + -- the enclosing construct. Skip freezing in this case. + + if Ekind (Entity (N)) = E_Discriminant then + return; + + -- For the case of a reference to the enclosing record, + -- (or task or protected type), we look for a type that + -- matches the current scope. + + elsif Entity (N) = Current_Scope then + return; + end if; + end if; + + -- If we have an enumeration literal that appears as the + -- choice in the aggregate of an enumeration representation + -- clause, then freezing does not occur (RM 13.14(9)). + + when N_Enumeration_Representation_Clause => + + -- The case we are looking for is an enumeration literal + + if (Nkind (N) = N_Identifier or Nkind (N) = N_Character_Literal) + and then Is_Enumeration_Type (Etype (N)) + then + -- If enumeration literal appears directly as the choice, + -- do not freeze (this is the normal non-overloade case) + + if Nkind (Parent (N)) = N_Component_Association + and then First (Choices (Parent (N))) = N + then + return; + + -- If enumeration literal appears as the name of a + -- function which is the choice, then also do not freeze. + -- This happens in the overloaded literal case, where the + -- enumeration literal is temporarily changed to a function + -- call for overloading analysis purposes. + + elsif Nkind (Parent (N)) = N_Function_Call + and then + Nkind (Parent (Parent (N))) = N_Component_Association + and then + First (Choices (Parent (Parent (N)))) = Parent (N) + then + return; + end if; + end if; + + -- Normally if the parent is a handled sequence of statements, + -- then the current node must be a statement, and that is an + -- appropriate place to insert a freeze node. + + when N_Handled_Sequence_Of_Statements => + + -- An exception occurs when the sequence of statements is + -- for an expander generated body that did not do the usual + -- freeze all operation. In this case we usually want to + -- freeze outside this body, not inside it, and we skip + -- past the subprogram body that we are inside. + + if In_Exp_Body (Parent_P) then + + -- However, we *do* want to freeze at this point if we have + -- an entity to freeze, and that entity is declared *inside* + -- the body of the expander generated procedure. This case + -- is recognized by the scope of the type, which is either + -- the spec for some enclosing body, or (in the case of + -- init_procs, for which there are no separate specs) the + -- current scope. + + declare + Subp : constant Node_Id := Parent (Parent_P); + Cspc : Entity_Id; + + begin + if Nkind (Subp) = N_Subprogram_Body then + Cspc := Corresponding_Spec (Subp); + + if (Present (Typ) and then Scope (Typ) = Cspc) + or else + (Present (Nam) and then Scope (Nam) = Cspc) + then + exit; + + elsif Present (Typ) + and then Scope (Typ) = Current_Scope + and then Current_Scope = Defining_Entity (Subp) + then + exit; + end if; + end if; + end; + + -- If not that exception to the exception, then this is + -- where we delay the freeze till outside the body. + + Parent_P := Parent (Parent_P); + Freeze_Outside := True; + + -- Here if normal case where we are in handled statement + -- sequence and want to do the insertion right there. + + else + exit; + end if; + + -- If parent is a body or a spec or a block, then the current + -- node is a statement or declaration and we can insert the + -- freeze node before it. + + when N_Package_Specification | + N_Package_Body | + N_Subprogram_Body | + N_Task_Body | + N_Protected_Body | + N_Entry_Body | + N_Block_Statement => exit; + + -- The expander is allowed to define types in any statements list, + -- so any of the following parent nodes also mark a freezing point + -- if the actual node is in a list of statements or declarations. + + when N_Exception_Handler | + N_If_Statement | + N_Elsif_Part | + N_Case_Statement_Alternative | + N_Compilation_Unit_Aux | + N_Selective_Accept | + N_Accept_Alternative | + N_Delay_Alternative | + N_Conditional_Entry_Call | + N_Entry_Call_Alternative | + N_Triggering_Alternative | + N_Abortable_Part | + N_Freeze_Entity => + + exit when Is_List_Member (P); + + -- Note: The N_Loop_Statement is a special case. A type that + -- appears in the source can never be frozen in a loop (this + -- occurs only because of a loop expanded by the expander), + -- so we keep on going. Otherwise we terminate the search. + -- Same is true of any entity which comes from source. (if they + -- have a predefined type, that type does not appear to come + -- from source, but the entity should not be frozen here). + + when N_Loop_Statement => + exit when not Comes_From_Source (Etype (N)) + and then (No (Nam) or else not Comes_From_Source (Nam)); + + -- For all other cases, keep looking at parents + + when others => + null; + end case; + + -- We fall through the case if we did not yet find the proper + -- place in the free for inserting the freeze node, so climb! + + P := Parent_P; + end loop; + + -- If the expression appears in a record or an initialization + -- procedure, the freeze nodes are collected and attached to + -- the current scope, to be inserted and analyzed on exit from + -- the scope, to insure that generated entities appear in the + -- correct scope. If the expression is a default for a discriminant + -- specification, the scope is still void. The expression can also + -- appear in the discriminant part of a private or concurrent type. + + -- The other case requiring this special handling is if we are in + -- a default expression, since in that case we are about to freeze + -- a static type, and the freeze scope needs to be the outer scope, + -- not the scope of the subprogram with the default parameter. + + -- For default expressions in generic units, the Move_Freeze_Nodes + -- mechanism (see sem_ch12.adb) takes care of placing them at the + -- proper place, after the generic unit. + + if (In_Def_Exp and not Inside_A_Generic) + or else Freeze_Outside + or else (Is_Type (Current_Scope) + and then (not Is_Concurrent_Type (Current_Scope) + or else not Has_Completion (Current_Scope))) + or else Ekind (Current_Scope) = E_Void + then + declare + Loc : constant Source_Ptr := Sloc (Current_Scope); + Freeze_Nodes : List_Id := No_List; + + begin + if Present (Desig_Typ) then + Freeze_And_Append (Desig_Typ, Loc, Freeze_Nodes); + end if; + + if Present (Typ) then + Freeze_And_Append (Typ, Loc, Freeze_Nodes); + end if; + + if Present (Nam) then + Freeze_And_Append (Nam, Loc, Freeze_Nodes); + end if; + + if Is_Non_Empty_List (Freeze_Nodes) then + + if No (Scope_Stack.Table + (Scope_Stack.Last).Pending_Freeze_Actions) + then + Scope_Stack.Table + (Scope_Stack.Last).Pending_Freeze_Actions := + Freeze_Nodes; + else + Append_List (Freeze_Nodes, Scope_Stack.Table + (Scope_Stack.Last).Pending_Freeze_Actions); + end if; + end if; + end; + + return; + end if; + + -- Now we have the right place to do the freezing. First, a special + -- adjustment, if we are in default expression analysis mode, these + -- freeze actions must not be thrown away (normally all inserted + -- actions are thrown away in this mode. However, the freeze actions + -- are from static expressions and one of the important reasons we + -- are doing this special analysis is to get these freeze actions. + -- Therefore we turn off the In_Default_Expression mode to propagate + -- these freeze actions. This also means they get properly analyzed + -- and expanded. + + In_Default_Expression := False; + + -- Freeze the designated type of an allocator (RM 13.14(12)) + + if Present (Desig_Typ) then + Freeze_Before (P, Desig_Typ); + end if; + + -- Freeze type of expression (RM 13.14(9)). 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(10)) + + if Present (Nam) then + Freeze_Before (P, Nam); + end if; + + In_Default_Expression := In_Def_Exp; + end Freeze_Expression; + + ----------------------------- + -- Freeze_Fixed_Point_Type -- + ----------------------------- + + -- Certain fixed-point types and subtypes, including implicit base + -- types and declared first subtypes, have not yet set up a range. + -- This is because the range cannot be set until the Small and Size + -- values are known, and these are not known till the type is frozen. + + -- To signal this case, Scalar_Range contains an unanalyzed syntactic + -- range whose bounds are unanalyzed real literals. This routine will + -- recognize this case, and transform this range node into a properly + -- typed range with properly analyzed and resolved values. + + procedure Freeze_Fixed_Point_Type (Typ : Entity_Id) is + Rng : constant Node_Id := Scalar_Range (Typ); + Lo : constant Node_Id := Low_Bound (Rng); + Hi : constant Node_Id := High_Bound (Rng); + Btyp : constant Entity_Id := Base_Type (Typ); + Brng : constant Node_Id := Scalar_Range (Btyp); + BLo : constant Node_Id := Low_Bound (Brng); + BHi : constant Node_Id := High_Bound (Brng); + Small : constant Ureal := Small_Value (Typ); + Loval : Ureal; + Hival : Ureal; + Atype : Entity_Id; + + Actual_Size : Nat; + + function Fsize (Lov, Hiv : Ureal) return Nat; + -- Returns size of type with given bounds. Also leaves these + -- bounds set as the current bounds of the Typ. + + function Fsize (Lov, Hiv : Ureal) return Nat is + begin + Set_Realval (Lo, Lov); + Set_Realval (Hi, Hiv); + return Minimum_Size (Typ); + end Fsize; + + -- Start of processing for Freeze_Fixed_Point_Type; + + begin + -- If Esize of a subtype has not previously been set, set it now + + if Unknown_Esize (Typ) then + Atype := Ancestor_Subtype (Typ); + + if Present (Atype) then + Set_Size_Info (Typ, Atype); + else + Set_Size_Info (Typ, Base_Type (Typ)); + end if; + end if; + + -- Immediate return if the range is already analyzed. This means + -- that the range is already set, and does not need to be computed + -- by this routine. + + if Analyzed (Rng) then + return; + end if; + + -- Immediate return if either of the bounds raises Constraint_Error + + if Raises_Constraint_Error (Lo) + or else Raises_Constraint_Error (Hi) + then + return; + end if; + + Loval := Realval (Lo); + Hival := Realval (Hi); + + -- Ordinary fixed-point case + + if Is_Ordinary_Fixed_Point_Type (Typ) then + + -- For the ordinary fixed-point case, we are allowed to fudge the + -- end-points up or down by small. Generally we prefer to fudge + -- up, i.e. widen the bounds for non-model numbers so that the + -- end points are included. However there are cases in which this + -- cannot be done, and indeed cases in which we may need to narrow + -- the bounds. The following circuit makes the decision. + + -- Note: our terminology here is that Incl_EP means that the + -- bounds are widened by Small if necessary to include the end + -- points, and Excl_EP means that the bounds are narrowed by + -- Small to exclude the end-points if this reduces the size. + + -- Note that in the Incl case, all we care about is including the + -- end-points. In the Excl case, we want to narrow the bounds as + -- much as permitted by the RM, to give the smallest possible size. + + Fudge : declare + Loval_Incl_EP : Ureal; + Hival_Incl_EP : Ureal; + + Loval_Excl_EP : Ureal; + Hival_Excl_EP : Ureal; + + Size_Incl_EP : Nat; + Size_Excl_EP : Nat; + + Model_Num : Ureal; + First_Subt : Entity_Id; + Actual_Lo : Ureal; + Actual_Hi : Ureal; + + begin + -- First step. Base types are required to be symmetrical. Right + -- now, the base type range is a copy of the first subtype range. + -- This will be corrected before we are done, but right away we + -- need to deal with the case where both bounds are non-negative. + -- In this case, we set the low bound to the negative of the high + -- bound, to make sure that the size is computed to include the + -- required sign. Note that we do not need to worry about the + -- case of both bounds negative, because the sign will be dealt + -- with anyway. Furthermore we can't just go making such a bound + -- symmetrical, since in a twos-complement system, there is an + -- extra negative value which could not be accomodated on the + -- positive side. + + if Typ = Btyp + and then not UR_Is_Negative (Loval) + and then Hival > Loval + then + Loval := -Hival; + Set_Realval (Lo, Loval); + end if; + + -- Compute the fudged bounds. If the number is a model number, + -- then we do nothing to include it, but we are allowed to + -- backoff to the next adjacent model number when we exclude + -- it. If it is not a model number then we straddle the two + -- values with the model numbers on either side. + + Model_Num := UR_Trunc (Loval / Small) * Small; + + if Loval = Model_Num then + Loval_Incl_EP := Model_Num; + else + Loval_Incl_EP := Model_Num - Small; + end if; + + -- The low value excluding the end point is Small greater, but + -- we do not do this exclusion if the low value is positive, + -- since it can't help the size and could actually hurt by + -- crossing the high bound. + + if UR_Is_Negative (Loval_Incl_EP) then + Loval_Excl_EP := Loval_Incl_EP + Small; + else + Loval_Excl_EP := Loval_Incl_EP; + end if; + + -- Similar processing for upper bound and high value + + Model_Num := UR_Trunc (Hival / Small) * Small; + + if Hival = Model_Num then + Hival_Incl_EP := Model_Num; + else + Hival_Incl_EP := Model_Num + Small; + end if; + + if UR_Is_Positive (Hival_Incl_EP) then + Hival_Excl_EP := Hival_Incl_EP - Small; + else + Hival_Excl_EP := Hival_Incl_EP; + end if; + + -- One further adjustment is needed. In the case of subtypes, + -- we cannot go outside the range of the base type, or we get + -- peculiarities, and the base type range is already set. This + -- only applies to the Incl values, since clearly the Excl + -- values are already as restricted as they are allowed to be. + + if Typ /= Btyp then + Loval_Incl_EP := UR_Max (Loval_Incl_EP, Realval (BLo)); + Hival_Incl_EP := UR_Min (Hival_Incl_EP, Realval (BHi)); + end if; + + -- Get size including and excluding end points + + Size_Incl_EP := Fsize (Loval_Incl_EP, Hival_Incl_EP); + Size_Excl_EP := Fsize (Loval_Excl_EP, Hival_Excl_EP); + + -- No need to exclude end-points if it does not reduce size + + if Fsize (Loval_Incl_EP, Hival_Excl_EP) = Size_Excl_EP then + Loval_Excl_EP := Loval_Incl_EP; + end if; + + if Fsize (Loval_Excl_EP, Hival_Incl_EP) = Size_Excl_EP then + Hival_Excl_EP := Hival_Incl_EP; + end if; + + -- Now we set the actual size to be used. We want to use the + -- bounds fudged up to include the end-points but only if this + -- can be done without violating a specifically given size + -- size clause or causing an unacceptable increase in size. + + -- Case of size clause given + + if Has_Size_Clause (Typ) then + + -- Use the inclusive size only if it is consistent with + -- the explicitly specified size. + + if Size_Incl_EP <= RM_Size (Typ) then + Actual_Lo := Loval_Incl_EP; + Actual_Hi := Hival_Incl_EP; + Actual_Size := Size_Incl_EP; + + -- If the inclusive size is too large, we try excluding + -- the end-points (will be caught later if does not work). + + else + Actual_Lo := Loval_Excl_EP; + Actual_Hi := Hival_Excl_EP; + Actual_Size := Size_Excl_EP; + end if; + + -- Case of size clause not given + + else + -- If we have a base type whose corresponding first subtype + -- has an explicit size that is large enough to include our + -- end-points, then do so. There is no point in working hard + -- to get a base type whose size is smaller than the specified + -- size of the first subtype. + + First_Subt := First_Subtype (Typ); + + if Has_Size_Clause (First_Subt) + and then Size_Incl_EP <= Esize (First_Subt) + then + Actual_Size := Size_Incl_EP; + Actual_Lo := Loval_Incl_EP; + Actual_Hi := Hival_Incl_EP; + + -- If excluding the end-points makes the size smaller and + -- results in a size of 8,16,32,64, then we take the smaller + -- size. For the 64 case, this is compulsory. For the other + -- cases, it seems reasonable. We like to include end points + -- if we can, but not at the expense of moving to the next + -- natural boundary of size. + + elsif Size_Incl_EP /= Size_Excl_EP + and then + (Size_Excl_EP = 8 or else + Size_Excl_EP = 16 or else + Size_Excl_EP = 32 or else + Size_Excl_EP = 64) + then + Actual_Size := Size_Excl_EP; + Actual_Lo := Loval_Excl_EP; + Actual_Hi := Hival_Excl_EP; + + -- Otherwise we can definitely include the end points + + else + Actual_Size := Size_Incl_EP; + Actual_Lo := Loval_Incl_EP; + Actual_Hi := Hival_Incl_EP; + end if; + + -- One pathological case: normally we never fudge a low + -- bound down, since it would seem to increase the size + -- (if it has any effect), but for ranges containing a + -- single value, or no values, the high bound can be + -- small too large. Consider: + + -- type t is delta 2.0**(-14) + -- range 131072.0 .. 0; + + -- That lower bound is *just* outside the range of 32 + -- bits, and does need fudging down in this case. Note + -- that the bounds will always have crossed here, since + -- the high bound will be fudged down if necessary, as + -- in the case of: + + -- type t is delta 2.0**(-14) + -- range 131072.0 .. 131072.0; + + -- So we can detect the situation by looking for crossed + -- bounds, and if the bounds are crossed, and the low + -- bound is greater than zero, we will always back it + -- off by small, since this is completely harmless. + + if Actual_Lo > Actual_Hi then + if UR_Is_Positive (Actual_Lo) then + Actual_Lo := Loval_Incl_EP - Small; + Actual_Size := Fsize (Actual_Lo, Actual_Hi); + + -- And of course, we need to do exactly the same parallel + -- fudge for flat ranges in the negative region. + + elsif UR_Is_Negative (Actual_Hi) then + Actual_Hi := Hival_Incl_EP + Small; + Actual_Size := Fsize (Actual_Lo, Actual_Hi); + end if; + end if; + end if; + + Set_Realval (Lo, Actual_Lo); + Set_Realval (Hi, Actual_Hi); + end Fudge; + + -- For the decimal case, none of this fudging is required, since there + -- are no end-point problems in the decimal case (the end-points are + -- always included). + + else + Actual_Size := Fsize (Loval, Hival); + end if; + + -- At this stage, the actual size has been calculated and the proper + -- required bounds are stored in the low and high bounds. + + if Actual_Size > 64 then + Error_Msg_Uint_1 := UI_From_Int (Actual_Size); + Error_Msg_N + ("size required (^) for type& too large, maximum is 64", Typ); + Actual_Size := 64; + end if; + + -- Check size against explicit given size + + if Has_Size_Clause (Typ) then + if Actual_Size > RM_Size (Typ) then + Error_Msg_Uint_1 := RM_Size (Typ); + Error_Msg_Uint_2 := UI_From_Int (Actual_Size); + Error_Msg_NE + ("size given (^) for type& too small, minimum is ^", + Size_Clause (Typ), Typ); + + else + Actual_Size := UI_To_Int (Esize (Typ)); + end if; + + -- Increase size to next natural boundary if no size clause given + + else + if Actual_Size <= 8 then + Actual_Size := 8; + elsif Actual_Size <= 16 then + Actual_Size := 16; + elsif Actual_Size <= 32 then + Actual_Size := 32; + else + Actual_Size := 64; + end if; + + Init_Esize (Typ, Actual_Size); + Adjust_Esize_For_Alignment (Typ); + end if; + + -- If we have a base type, then expand the bounds so that they + -- extend to the full width of the allocated size in bits, to + -- avoid junk range checks on intermediate computations. + + if Base_Type (Typ) = Typ then + Set_Realval (Lo, -(Small * (Uint_2 ** (Actual_Size - 1)))); + Set_Realval (Hi, (Small * (Uint_2 ** (Actual_Size - 1) - 1))); + end if; + + -- Final step is to reanalyze the bounds using the proper type + -- and set the Corresponding_Integer_Value fields of the literals. + + Set_Etype (Lo, Empty); + Set_Analyzed (Lo, False); + Analyze (Lo); + + -- Resolve with universal fixed if the base type, and the base + -- type if it is a subtype. Note we can't resolve the base type + -- with itself, that would be a reference before definition. + + if Typ = Btyp then + Resolve (Lo, Universal_Fixed); + else + Resolve (Lo, Btyp); + end if; + + -- Set corresponding integer value for bound + + Set_Corresponding_Integer_Value + (Lo, UR_To_Uint (Realval (Lo) / Small)); + + -- Similar processing for high bound + + Set_Etype (Hi, Empty); + Set_Analyzed (Hi, False); + Analyze (Hi); + + if Typ = Btyp then + Resolve (Hi, Universal_Fixed); + else + Resolve (Hi, Btyp); + end if; + + Set_Corresponding_Integer_Value + (Hi, UR_To_Uint (Realval (Hi) / Small)); + + -- Set type of range to correspond to bounds + + Set_Etype (Rng, Etype (Lo)); + + -- Set Esize to calculated size and also set RM_Size + + Init_Esize (Typ, Actual_Size); + + -- Set RM_Size if not already set. If already set, check value + + declare + Minsiz : constant Uint := UI_From_Int (Minimum_Size (Typ)); + + begin + if RM_Size (Typ) /= Uint_0 then + if RM_Size (Typ) < Minsiz then + Error_Msg_Uint_1 := RM_Size (Typ); + Error_Msg_Uint_2 := Minsiz; + Error_Msg_NE + ("size given (^) for type& too small, minimum is ^", + Size_Clause (Typ), Typ); + end if; + + else + Set_RM_Size (Typ, Minsiz); + end if; + end; + + end Freeze_Fixed_Point_Type; + + ------------------ + -- Freeze_Itype -- + ------------------ + + procedure Freeze_Itype (T : Entity_Id; N : Node_Id) is + L : List_Id; + + begin + Set_Has_Delayed_Freeze (T); + L := Freeze_Entity (T, Sloc (N)); + + if Is_Non_Empty_List (L) then + Insert_Actions (N, L); + end if; + end Freeze_Itype; + + -------------------------- + -- Freeze_Static_Object -- + -------------------------- + + procedure Freeze_Static_Object (E : Entity_Id) is + + Cannot_Be_Static : exception; + -- Exception raised if the type of a static object cannot be made + -- static. This happens if the type depends on non-global objects. + + procedure Ensure_Expression_Is_SA (N : Node_Id); + -- Called to ensure that an expression used as part of a type + -- definition is statically allocatable, which means that the type + -- of the expression is statically allocatable, and the expression + -- is either static, or a reference to a library level constant. + + procedure Ensure_Type_Is_SA (Typ : Entity_Id); + -- Called to mark a type as static, checking that it is possible + -- to set the type as static. If it is not possible, then the + -- exception Cannot_Be_Static is raised. + + ----------------------------- + -- Ensure_Expression_Is_SA -- + ----------------------------- + + procedure Ensure_Expression_Is_SA (N : Node_Id) is + Ent : Entity_Id; + + begin + Ensure_Type_Is_SA (Etype (N)); + + if Is_Static_Expression (N) then + return; + + elsif Nkind (N) = N_Identifier then + Ent := Entity (N); + + if Present (Ent) + and then Ekind (Ent) = E_Constant + and then Is_Library_Level_Entity (Ent) + then + return; + end if; + end if; + + raise Cannot_Be_Static; + end Ensure_Expression_Is_SA; + + ----------------------- + -- Ensure_Type_Is_SA -- + ----------------------- + + procedure Ensure_Type_Is_SA (Typ : Entity_Id) is + N : Node_Id; + C : Entity_Id; + + begin + -- If type is library level, we are all set + + if Is_Library_Level_Entity (Typ) then + return; + end if; + + -- We are also OK if the type is already marked as statically + -- allocated, which means we processed it before. + + if Is_Statically_Allocated (Typ) then + return; + end if; + + -- Mark type as statically allocated + + Set_Is_Statically_Allocated (Typ); + + -- Check that it is safe to statically allocate this type + + if Is_Scalar_Type (Typ) or else Is_Real_Type (Typ) then + Ensure_Expression_Is_SA (Type_Low_Bound (Typ)); + Ensure_Expression_Is_SA (Type_High_Bound (Typ)); + + elsif Is_Array_Type (Typ) then + N := First_Index (Typ); + while Present (N) loop + Ensure_Type_Is_SA (Etype (N)); + Next_Index (N); + end loop; + + Ensure_Type_Is_SA (Component_Type (Typ)); + + elsif Is_Access_Type (Typ) then + if Ekind (Designated_Type (Typ)) = E_Subprogram_Type then + + declare + F : Entity_Id; + T : constant Entity_Id := Etype (Designated_Type (Typ)); + + begin + if T /= Standard_Void_Type then + Ensure_Type_Is_SA (T); + end if; + + F := First_Formal (Designated_Type (Typ)); + + while Present (F) loop + Ensure_Type_Is_SA (Etype (F)); + Next_Formal (F); + end loop; + end; + + else + Ensure_Type_Is_SA (Designated_Type (Typ)); + end if; + + elsif Is_Record_Type (Typ) then + C := First_Entity (Typ); + + while Present (C) loop + if Ekind (C) = E_Discriminant + or else Ekind (C) = E_Component + then + Ensure_Type_Is_SA (Etype (C)); + + elsif Is_Type (C) then + Ensure_Type_Is_SA (C); + end if; + + Next_Entity (C); + end loop; + + elsif Ekind (Typ) = E_Subprogram_Type then + Ensure_Type_Is_SA (Etype (Typ)); + + C := First_Formal (Typ); + while Present (C) loop + Ensure_Type_Is_SA (Etype (C)); + Next_Formal (C); + end loop; + + else + raise Cannot_Be_Static; + end if; + end Ensure_Type_Is_SA; + + -- Start of processing for Freeze_Static_Object + + begin + Ensure_Type_Is_SA (Etype (E)); + + 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; + + -- 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 + 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, do not permit 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 + then + Error_Msg_NE + ("convention for& does not permit returning " & + "unconstrained array type", E, 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 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 subprograms. + + if OpenVMS_On_Target then + if 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 subprogram", F); + end if; + + Next_Formal (F); + end loop; + end if; + end if; + + end Freeze_Subprogram; + + ----------------------- + -- Is_Fully_Defined -- + ----------------------- + + -- Should this be in Sem_Util ??? + + 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)); + else + return not Is_Private_Type (T) + or else Present (Full_View (Base_Type (T))); + end if; + end Is_Fully_Defined; + + --------------------------------- + -- 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 Nkind (Dcopy) = N_Null + 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 that 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, Etype (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; + + --------------------------- + -- Set_Debug_Info_Needed -- + --------------------------- + + procedure Set_Debug_Info_Needed (T : Entity_Id) is + begin + if No (T) + or else Needs_Debug_Info (T) + or else Debug_Info_Off (T) + then + return; + else + Set_Needs_Debug_Info (T); + end if; + + if Is_Object (T) then + Set_Debug_Info_Needed (Etype (T)); + + elsif Is_Type (T) then + Set_Debug_Info_Needed (Etype (T)); + + if Is_Record_Type (T) then + declare + Ent : Entity_Id := First_Entity (T); + begin + while Present (Ent) loop + Set_Debug_Info_Needed (Ent); + Next_Entity (Ent); + end loop; + end; + + elsif Is_Array_Type (T) then + Set_Debug_Info_Needed (Component_Type (T)); + + declare + Indx : Node_Id := First_Index (T); + begin + while Present (Indx) loop + Set_Debug_Info_Needed (Etype (Indx)); + Indx := Next_Index (Indx); + end loop; + end; + + if Is_Packed (T) then + Set_Debug_Info_Needed (Packed_Array_Type (T)); + end if; + + elsif Is_Access_Type (T) then + Set_Debug_Info_Needed (Directly_Designated_Type (T)); + + elsif Is_Private_Type (T) then + Set_Debug_Info_Needed (Full_View (T)); + + elsif Is_Protected_Type (T) then + Set_Debug_Info_Needed (Corresponding_Record_Type (T)); + end if; + end if; + + end Set_Debug_Info_Needed; + +end Freeze; |