-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2015, 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- --
with Sem_Aux; use Sem_Aux;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch6; use Sem_Ch6;
+with Sem_Ch8; use Sem_Ch8;
with Sem_Eval; use Sem_Eval;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Snames; use Snames;
with Sinfo; use Sinfo;
+with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
-- (returning the designated tagged type in the case of an access
-- parameter); otherwise returns empty.
+ function Find_Hidden_Overridden_Primitive (S : Entity_Id) return Entity_Id;
+ -- [Ada 2012:AI-0125] Find an inherited hidden primitive of the dispatching
+ -- type of S that has the same name of S, a type-conformant profile, an
+ -- original corresponding operation O that is a primitive of a visible
+ -- ancestor of the dispatching type of S and O is visible at the point of
+ -- of declaration of S. If the entity is found the Alias of S is set to the
+ -- original corresponding operation S and its Overridden_Operation is set
+ -- to the found entity; otherwise return Empty.
+ --
+ -- This routine does not search for non-hidden primitives since they are
+ -- covered by the normal Ada 2005 rules.
+
+ function Is_Inherited_Public_Operation (Op : Entity_Id) return Boolean;
+ -- Check whether a primitive operation is inherited from an operation
+ -- declared in the visible part of its package.
+
-------------------------------
-- Add_Dispatching_Operation --
-------------------------------
Append_Unique_Elmt (New_Op, List);
end Add_Dispatching_Operation;
+ ---------------------------
+ -- Covers_Some_Interface --
+ ---------------------------
+
+ function Covers_Some_Interface (Prim : Entity_Id) return Boolean is
+ Tagged_Type : constant Entity_Id := Find_Dispatching_Type (Prim);
+ Elmt : Elmt_Id;
+ E : Entity_Id;
+
+ begin
+ pragma Assert (Is_Dispatching_Operation (Prim));
+
+ -- Although this is a dispatching primitive we must check if its
+ -- dispatching type is available because it may be the primitive
+ -- of a private type not defined as tagged in its partial view.
+
+ if Present (Tagged_Type) and then Has_Interfaces (Tagged_Type) then
+
+ -- If the tagged type is frozen then the internal entities associated
+ -- with interfaces are available in the list of primitives of the
+ -- tagged type and can be used to speed up this search.
+
+ if Is_Frozen (Tagged_Type) then
+ Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
+ while Present (Elmt) loop
+ E := Node (Elmt);
+
+ if Present (Interface_Alias (E))
+ and then Alias (E) = Prim
+ then
+ return True;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ -- Otherwise we must collect all the interface primitives and check
+ -- if the Prim will override some interface primitive.
+
+ else
+ declare
+ Ifaces_List : Elist_Id;
+ Iface_Elmt : Elmt_Id;
+ Iface : Entity_Id;
+ Iface_Prim : Entity_Id;
+
+ begin
+ Collect_Interfaces (Tagged_Type, Ifaces_List);
+ Iface_Elmt := First_Elmt (Ifaces_List);
+ while Present (Iface_Elmt) loop
+ Iface := Node (Iface_Elmt);
+
+ Elmt := First_Elmt (Primitive_Operations (Iface));
+ while Present (Elmt) loop
+ Iface_Prim := Node (Elmt);
+
+ if Chars (Iface) = Chars (Prim)
+ and then Is_Interface_Conformant
+ (Tagged_Type, Iface_Prim, Prim)
+ then
+ return True;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end;
+ end if;
+ end if;
+
+ return False;
+ end Covers_Some_Interface;
+
-------------------------------
-- Check_Controlling_Formals --
-------------------------------
-- In Ada 2005, access parameters can have defaults
if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
- and then Ada_Version < Ada_05
+ and then Ada_Version < Ada_2005
then
Error_Msg_N
("default not allowed for controlling access parameter",
Next_Formal (Formal);
end loop;
- if Ekind (Subp) = E_Function
- or else
- Ekind (Subp) = E_Generic_Function
- then
+ if Ekind_In (Subp, E_Function, E_Generic_Function) then
Ctrl_Type := Check_Controlling_Type (Etype (Subp), Subp);
if Present (Ctrl_Type) then
-- Ada 2005 (AI-50217)
- elsif From_With_Type (Designated_Type (T))
+ elsif From_Limited_With (Designated_Type (T))
and then Present (Non_Limited_View (Designated_Type (T)))
+ and then Scope (Designated_Type (T)) = Scope (Subp)
then
if Is_First_Subtype (Non_Limited_View (Designated_Type (T))) then
Tagged_Type := Non_Limited_View (Designated_Type (T));
procedure Check_Dispatching_Context is
Subp : constant Entity_Id := Entity (Name (N));
+ Typ : constant Entity_Id := Etype (Subp);
Par : Node_Id;
+ procedure Abstract_Context_Error;
+ -- Error for abstract call dispatching on result is not dispatching
+
+ ----------------------------
+ -- Abstract_Context_Error --
+ ----------------------------
+
+ procedure Abstract_Context_Error is
+ begin
+ if Ekind (Subp) = E_Function then
+ Error_Msg_N
+ ("call to abstract function must be dispatching", N);
+
+ -- This error can occur for a procedure in the case of a call to
+ -- an abstract formal procedure with a statically tagged operand.
+
+ else
+ Error_Msg_N
+ ("call to abstract procedure must be dispatching",
+ N);
+ end if;
+ end Abstract_Context_Error;
+
+ -- Start of processing for Check_Dispatching_Context
+
begin
if Is_Abstract_Subprogram (Subp)
and then No (Controlling_Argument (N))
Set_Entity (Name (N), Alias (Subp));
return;
+ -- An obscure special case: a null procedure may have a class-
+ -- wide pre/postcondition that includes a call to an abstract
+ -- subp. Calls within the expression may not have been rewritten
+ -- as dispatching calls yet, because the null body appears in
+ -- the current declarative part. The expression will be properly
+ -- rewritten/reanalyzed when the postcondition procedure is built.
+
+ -- Similarly, if this is a pre/postcondition for an abstract
+ -- subprogram, it may call another abstract function which is
+ -- a primitive of an abstract type. The call is non-dispatching
+ -- but will be legal in overridings of the operation.
+
+ elsif In_Spec_Expression
+ and then Is_Subprogram (Current_Scope)
+ and then
+ ((Nkind (Parent (Current_Scope)) = N_Procedure_Specification
+ and then Null_Present (Parent (Current_Scope)))
+ or else Is_Abstract_Subprogram (Current_Scope))
+ then
+ null;
+
+ elsif Ekind (Current_Scope) = E_Function
+ and then Nkind (Unit_Declaration_Node (Current_Scope)) =
+ N_Generic_Subprogram_Declaration
+ then
+ null;
+
else
+ -- We need to determine whether the context of the call
+ -- provides a tag to make the call dispatching. This requires
+ -- the call to be the actual in an enclosing call, and that
+ -- actual must be controlling. If the call is an operand of
+ -- equality, the other operand must not ve abstract.
+
+ if not Is_Tagged_Type (Typ)
+ and then not
+ (Ekind (Typ) = E_Anonymous_Access_Type
+ and then Is_Tagged_Type (Designated_Type (Typ)))
+ then
+ Abstract_Context_Error;
+ return;
+ end if;
+
Par := Parent (N);
+
+ if Nkind (Par) = N_Parameter_Association then
+ Par := Parent (Par);
+ end if;
+
while Present (Par) loop
if Nkind_In (Par, N_Function_Call,
- N_Procedure_Call_Statement,
- N_Assignment_Statement,
- N_Op_Eq,
- N_Op_Ne)
- and then Is_Tagged_Type (Etype (Subp))
+ N_Procedure_Call_Statement)
+ and then Is_Entity_Name (Name (Par))
then
- return;
+ declare
+ A : Node_Id;
+ F : Entity_Id;
+
+ begin
+ -- Find formal for which call is the actual.
+
+ F := First_Formal (Entity (Name (Par)));
+ A := First_Actual (Par);
+ while Present (F) loop
+ if Is_Controlling_Formal (F)
+ and then (N = A or else Parent (N) = A)
+ then
+ return;
+ end if;
- elsif Nkind (Par) = N_Qualified_Expression
- or else Nkind (Par) = N_Unchecked_Type_Conversion
- then
- Par := Parent (Par);
+ Next_Formal (F);
+ Next_Actual (A);
+ end loop;
- else
- if Ekind (Subp) = E_Function then
Error_Msg_N
("call to abstract function must be dispatching", N);
+ return;
+ end;
- -- This error can occur for a procedure in the case of a
- -- call to an abstract formal procedure with a statically
- -- tagged operand.
+ -- For equalitiy operators, one of the operands must be
+ -- statically or dynamically tagged.
- else
- Error_Msg_N
- ("call to abstract procedure must be dispatching",
- N);
+ elsif Nkind_In (Par, N_Op_Eq, N_Op_Ne) then
+ if N = Right_Opnd (Par)
+ and then Is_Tag_Indeterminate (Left_Opnd (Par))
+ then
+ Abstract_Context_Error;
+
+ elsif N = Left_Opnd (Par)
+ and then Is_Tag_Indeterminate (Right_Opnd (Par))
+ then
+ Abstract_Context_Error;
end if;
return;
+
+ elsif Nkind (Par) = N_Assignment_Statement then
+ return;
+
+ elsif Nkind (Par) = N_Qualified_Expression
+ or else Nkind (Par) = N_Unchecked_Type_Conversion
+ then
+ Par := Parent (Par);
+
+ else
+ Abstract_Context_Error;
+ return;
end if;
end loop;
end if;
-- If the call doesn't have a controlling actual but does have an
-- indeterminate actual that requires dispatching treatment, then an
- -- object is needed that will serve as the controlling argument for a
- -- dispatching call on the indeterminate actual. This can only occur
- -- in the unusual situation of a default actual given by a
- -- tag-indeterminate call and where the type of the call is an
+ -- object is needed that will serve as the controlling argument for
+ -- a dispatching call on the indeterminate actual. This can only
+ -- occur in the unusual situation of a default actual given by
+ -- a tag-indeterminate call and where the type of the call is an
-- ancestor of the type associated with a containing call to an
-- inherited operation (see AI-239).
- -- Rather than create an object of the tagged type, which would be
- -- problematic for various reasons (default initialization,
- -- discriminants), the tag of the containing call's associated tagged
- -- type is directly used to control the dispatching.
+ -- Rather than create an object of the tagged type, which would
+ -- be problematic for various reasons (default initialization,
+ -- discriminants), the tag of the containing call's associated
+ -- tagged type is directly used to control the dispatching.
if No (Control)
and then Indeterm_Ancestor_Call
-- The tag is inherited from the enclosing call (the node
-- we are currently analyzing). Explicitly expand the
-- actual, since the previous call to Expand (from
- -- Resolve_Call) had no way of knowing about the required
- -- dispatching.
+ -- Resolve_Call) had no way of knowing about the
+ -- required dispatching.
Propagate_Tag (Control, Actual);
end if;
if Present (Func) and then Is_Abstract_Subprogram (Func) then
- Error_Msg_N (
- "call to abstract function must be dispatching", N);
+ Error_Msg_N
+ ("call to abstract function must be dispatching", N);
end if;
end if;
procedure Check_Dispatching_Operation (Subp, Old_Subp : Entity_Id) is
Tagged_Type : Entity_Id;
- Has_Dispatching_Parent : Boolean := False;
- Body_Is_Last_Primitive : Boolean := False;
+ Has_Dispatching_Parent : Boolean := False;
+ Body_Is_Last_Primitive : Boolean := False;
+ Ovr_Subp : Entity_Id := Empty;
begin
- if Ekind (Subp) /= E_Procedure and then Ekind (Subp) /= E_Function then
+ if not Ekind_In (Subp, E_Procedure, E_Function) then
return;
end if;
Set_Is_Dispatching_Operation (Subp, False);
Tagged_Type := Find_Dispatching_Type (Subp);
- -- Ada 2005 (AI-345)
+ -- Ada 2005 (AI-345): Use the corresponding record (if available).
+ -- Required because primitives of concurrent types are attached
+ -- to the corresponding record (not to the concurrent type).
- if Ada_Version = Ada_05
+ if Ada_Version >= Ada_2005
and then Present (Tagged_Type)
and then Is_Concurrent_Type (Tagged_Type)
+ and then Present (Corresponding_Record_Type (Tagged_Type))
then
- -- Protect the frontend against previously detected errors
-
- if No (Corresponding_Record_Type (Tagged_Type)) then
- return;
- end if;
-
Tagged_Type := Corresponding_Record_Type (Tagged_Type);
end if;
and then not Is_Generic_Type (Typ)
and then not In_Instance
then
- Error_Msg_N ("?declaration of& is too late!", Subp);
- Error_Msg_NE
- ("\spec should appear immediately after declaration of &!",
- Subp, Typ);
+ Error_Msg_N ("??declaration of& is too late!", Subp);
+ Error_Msg_NE -- CODEFIX??
+ ("\??spec should appear immediately after declaration "
+ & "of & !", Subp, Typ);
exit;
end if;
Typ := Etype (Subp);
end if;
- if not Is_Class_Wide_Type (Typ)
+ -- The following should be better commented, especially since
+ -- we just added several new conditions here ???
+
+ if Comes_From_Source (Subp)
and then Is_Interface (Typ)
+ and then not Is_Class_Wide_Type (Typ)
and then not Is_Derived_Type (Typ)
+ and then not Is_Generic_Type (Typ)
+ and then not In_Instance
then
- Error_Msg_N ("?declaration of& is too late!", Subp);
+ Error_Msg_N ("??declaration of& is too late!", Subp);
Error_Msg_NE
- ("\spec should appear immediately after declaration of &!",
- Subp, Typ);
+ ("\??spec should appear immediately after declaration "
+ & "of & !", Subp, Typ);
end if;
end if;
end;
and then not Comes_From_Source (Subp)
and then not Has_Dispatching_Parent
then
- -- Complete decoration if internally built subprograms that override
+ -- Complete decoration of internally built subprograms that override
-- a dispatching primitive. These entities correspond with the
-- following cases:
-- type by Make_Controlling_Function_Wrappers. However, attribute
-- Is_Dispatching_Operation must be set to true.
- -- 2. Subprograms associated with stream attributes (built by
+ -- 2. Ada 2005 (AI-251): Wrapper procedures of null interface
+ -- primitives.
+
+ -- 3. Subprograms associated with stream attributes (built by
-- New_Stream_Subprogram)
if Present (Old_Subp)
- and then Is_Overriding_Operation (Subp)
+ and then Present (Overridden_Operation (Subp))
and then Is_Dispatching_Operation (Old_Subp)
then
pragma Assert
- ((Ekind (Subp) = E_Function
- and then Is_Dispatching_Operation (Old_Subp)
- and then Is_Null_Extension (Base_Type (Etype (Subp))))
- or else Get_TSS_Name (Subp) = TSS_Stream_Read
- or else Get_TSS_Name (Subp) = TSS_Stream_Write);
-
+ ((Ekind (Subp) = E_Function
+ and then Is_Dispatching_Operation (Old_Subp)
+ and then Is_Null_Extension (Base_Type (Etype (Subp))))
+ or else
+ (Ekind (Subp) = E_Procedure
+ and then Is_Dispatching_Operation (Old_Subp)
+ and then Present (Alias (Old_Subp))
+ and then Is_Null_Interface_Primitive
+ (Ultimate_Alias (Old_Subp)))
+ or else Get_TSS_Name (Subp) = TSS_Stream_Read
+ or else Get_TSS_Name (Subp) = TSS_Stream_Write);
+
+ Check_Controlling_Formals (Tagged_Type, Subp);
+ Override_Dispatching_Operation (Tagged_Type, Old_Subp, Subp);
Set_Is_Dispatching_Operation (Subp);
end if;
Decl_Item : Node_Id;
begin
- -- ??? The checks here for whether the type has been
- -- frozen prior to the new body are not complete. It's
- -- not simple to check frozenness at this point since
- -- the body has already caused the type to be prematurely
- -- frozen in Analyze_Declarations, but we're forced to
- -- recheck this here because of the odd rule interpretation
- -- that allows the overriding if the type wasn't frozen
- -- prior to the body. The freezing action should probably
- -- be delayed until after the spec is seen, but that's
- -- a tricky change to the delicate freezing code.
+ -- ??? The checks here for whether the type has been frozen
+ -- prior to the new body are not complete. It's not simple
+ -- to check frozenness at this point since the body has
+ -- already caused the type to be prematurely frozen in
+ -- Analyze_Declarations, but we're forced to recheck this
+ -- here because of the odd rule interpretation that allows
+ -- the overriding if the type wasn't frozen prior to the
+ -- body. The freezing action should probably be delayed
+ -- until after the spec is seen, but that's a tricky
+ -- change to the delicate freezing code.
-- Look at each declaration following the type up until the
-- new subprogram body. If any of the declarations is a body
elsif Is_Frozen (Subp) then
-- The subprogram body declares a primitive operation.
- -- if the subprogram is already frozen, we must update
+ -- If the subprogram is already frozen, we must update
-- its dispatching information explicitly here. The
-- information is taken from the overridden subprogram.
-- We must also generate a cross-reference entry because
if Present (DTC_Entity (Old_Subp)) then
Set_DTC_Entity (Subp, DTC_Entity (Old_Subp));
- Set_DT_Position (Subp, DT_Position (Old_Subp));
+ Set_DT_Position_Value (Subp, DT_Position (Old_Subp));
if not Restriction_Active (No_Dispatching_Calls) then
if Building_Static_DT (Tagged_Type) then
if Has_Dispatch_Table (Tagged_Type) then
Error_Msg_N
- ("overriding of& is too late for building" &
- " static dispatch tables!", Subp);
+ ("overriding of& is too late for building "
+ & " static dispatch tables!", Subp);
Error_Msg_N
- ("\spec should appear immediately after" &
- " the type!", Subp);
+ ("\spec should appear immediately after "
+ & "the type!", Subp);
end if;
+ -- No code required to register primitives in VM
+ -- targets
+
+ elsif VM_Target /= No_VM then
+ null;
+
else
Insert_Actions_After (Subp_Body,
Register_Primitive (Sloc (Subp_Body),
end if;
-- Indicate that this is an overriding operation,
- -- and replace the overriden entry in the list of
+ -- and replace the overridden entry in the list of
-- primitive operations, which is used for xref
-- generation subsequently.
-- If the type is not frozen yet and we are not in the overriding
-- case it looks suspiciously like an attempt to define a primitive
-- operation, which requires the declaration to be in a package spec
- -- (3.2.3(6)).
-
- elsif not Is_Frozen (Tagged_Type) then
+ -- (3.2.3(6)). Only report cases where the type and subprogram are
+ -- in the same declaration list (by checking the enclosing parent
+ -- declarations), to avoid spurious warnings on subprograms in
+ -- instance bodies when the type is declared in the instance spec
+ -- but hasn't been frozen by the instance body.
+
+ elsif not Is_Frozen (Tagged_Type)
+ and then In_Same_List (Parent (Tagged_Type), Parent (Parent (Subp)))
+ then
Error_Msg_N
- ("?not dispatching (must be defined in a package spec)", Subp);
+ ("??not dispatching (must be defined in a package spec)", Subp);
return;
-- When the type is frozen, it is legitimate to define a new
elsif Is_Frozen (Tagged_Type) and then not Has_Dispatching_Parent then
Error_Msg_N ("this primitive operation is declared too late", Subp);
Error_Msg_NE
- ("?no primitive operations for& after this line",
+ ("??no primitive operations for& after this line",
Freeze_Node (Tagged_Type),
Tagged_Type);
return;
Check_Controlling_Formals (Tagged_Type, Subp);
+ Ovr_Subp := Old_Subp;
+
+ -- [Ada 2012:AI-0125]: Search for inherited hidden primitive that may be
+ -- overridden by Subp. This only applies to source subprograms, and
+ -- their declaration must carry an explicit overriding indicator.
+
+ if No (Ovr_Subp)
+ and then Ada_Version >= Ada_2012
+ and then Comes_From_Source (Subp)
+ and then
+ Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
+ then
+ Ovr_Subp := Find_Hidden_Overridden_Primitive (Subp);
+
+ -- Verify that the proper overriding indicator has been supplied.
+
+ if Present (Ovr_Subp)
+ and then
+ not Must_Override (Specification (Unit_Declaration_Node (Subp)))
+ then
+ Error_Msg_NE ("missing overriding indicator for&", Subp, Subp);
+ end if;
+ end if;
+
-- Now it should be a correct primitive operation, put it in the list
- if Present (Old_Subp) then
+ if Present (Ovr_Subp) then
-- If the type has interfaces we complete this check after we set
-- attribute Is_Dispatching_Operation.
- Check_Subtype_Conformant (Subp, Old_Subp);
+ Check_Subtype_Conformant (Subp, Ovr_Subp);
+
+ -- A primitive operation with the name of a primitive controlled
+ -- operation does not override a non-visible overriding controlled
+ -- operation, i.e. one declared in a private part when the full
+ -- view of a type is controlled. Conversely, it will override a
+ -- visible operation that may be declared in a partial view when
+ -- the full view is controlled.
- if (Chars (Subp) = Name_Initialize
- or else Chars (Subp) = Name_Adjust
- or else Chars (Subp) = Name_Finalize)
+ if Nam_In (Chars (Subp), Name_Initialize, Name_Adjust, Name_Finalize)
and then Is_Controlled (Tagged_Type)
and then not Is_Visibly_Controlled (Tagged_Type)
+ and then not Is_Inherited_Public_Operation (Ovr_Subp)
then
- Set_Is_Overriding_Operation (Subp, False);
+ Set_Overridden_Operation (Subp, Empty);
-- If the subprogram specification carries an overriding
-- indicator, no need for the warning: it is either redundant,
else
Error_Msg_NE
- ("operation does not override inherited&?", Subp, Subp);
+ ("operation does not override inherited&??", Subp, Subp);
end if;
else
- Override_Dispatching_Operation (Tagged_Type, Old_Subp, Subp);
- Set_Is_Overriding_Operation (Subp);
+ Override_Dispatching_Operation (Tagged_Type, Ovr_Subp, Subp);
-- Ada 2005 (AI-251): In case of late overriding of a primitive
-- that covers abstract interface subprograms we must register it
-- in all the secondary dispatch tables associated with abstract
- -- interfaces. We do this now only if not building static tables.
- -- Otherwise the patch code is emitted after those tables are
- -- built, to prevent access_before_elaboration in gigi.
-
- if Body_Is_Last_Primitive then
+ -- interfaces. We do this now only if not building static tables,
+ -- nor when the expander is inactive (we avoid trying to register
+ -- primitives in semantics-only mode, since the type may not have
+ -- an associated dispatch table). Otherwise the patch code is
+ -- emitted after those tables are built, to prevent access before
+ -- elaboration in gigi.
+
+ if Body_Is_Last_Primitive and then Expander_Active then
declare
Subp_Body : constant Node_Id := Unit_Declaration_Node (Subp);
Elmt : Elmt_Id;
while Present (Elmt) loop
Prim := Node (Elmt);
+ -- No code required to register primitives in VM targets
+
if Present (Alias (Prim))
and then Present (Interface_Alias (Prim))
and then Alias (Prim) = Subp
and then not Building_Static_DT (Tagged_Type)
+ and then VM_Target = No_VM
then
Insert_Actions_After (Subp_Body,
Register_Primitive (Sloc (Subp_Body), Prim => Prim));
end if;
end if;
+ -- If the tagged type is a concurrent type then we must be compiling
+ -- with no code generation (we are either compiling a generic unit or
+ -- compiling under -gnatc mode) because we have previously tested that
+ -- no serious errors has been reported. In this case we do not add the
+ -- primitive to the list of primitives of Tagged_Type but we leave the
+ -- primitive decorated as a dispatching operation to be able to analyze
+ -- and report errors associated with the Object.Operation notation.
+
+ elsif Is_Concurrent_Type (Tagged_Type) then
+ pragma Assert (not Expander_Active);
+ null;
+
-- If no old subprogram, then we add this as a dispatching operation,
-- but we avoid doing this if an error was posted, to prevent annoying
-- cascaded errors.
-- subtype conformance against all the interfaces covered by this
-- primitive.
- if Present (Old_Subp)
+ if Present (Ovr_Subp)
and then Has_Interfaces (Tagged_Type)
then
declare
end if;
if not Body_Is_Last_Primitive then
- Set_DT_Position (Subp, No_Uint);
+ Set_DT_Position_Value (Subp, No_Uint);
elsif Has_Controlled_Component (Tagged_Type)
- and then
- (Chars (Subp) = Name_Initialize
- or else
- Chars (Subp) = Name_Adjust
- or else
- Chars (Subp) = Name_Finalize)
+ and then Nam_In (Chars (Subp), Name_Initialize,
+ Name_Adjust,
+ Name_Finalize,
+ Name_Finalize_Address)
then
declare
F_Node : constant Node_Id := Freeze_Node (Tagged_Type);
Old_Bod : Node_Id;
Old_Spec : Entity_Id;
- C_Names : constant array (1 .. 3) of Name_Id :=
+ C_Names : constant array (1 .. 4) of Name_Id :=
(Name_Initialize,
Name_Adjust,
- Name_Finalize);
+ Name_Finalize,
+ Name_Finalize_Address);
- D_Names : constant array (1 .. 3) of TSS_Name_Type :=
+ D_Names : constant array (1 .. 4) of TSS_Name_Type :=
(TSS_Deep_Initialize,
TSS_Deep_Adjust,
- TSS_Deep_Finalize);
+ TSS_Deep_Finalize,
+ TSS_Finalize_Address);
begin
-- Remove previous controlled function which was constructed and
Op1, Op2 : Elmt_Id;
Prev : Elmt_Id := No_Elmt;
- function Derives_From (Proc : Entity_Id) return Boolean;
- -- Check that Subp has the signature of an operation derived from Proc.
- -- Subp has an access parameter that designates Typ.
+ function Derives_From (Parent_Subp : Entity_Id) return Boolean;
+ -- Check that Subp has profile of an operation derived from Parent_Subp.
+ -- Subp must have a parameter or result type that is Typ or an access
+ -- parameter or access result type that designates Typ.
------------------
-- Derives_From --
------------------
- function Derives_From (Proc : Entity_Id) return Boolean is
+ function Derives_From (Parent_Subp : Entity_Id) return Boolean is
F1, F2 : Entity_Id;
begin
- if Chars (Proc) /= Chars (Subp) then
+ if Chars (Parent_Subp) /= Chars (Subp) then
return False;
end if;
- F1 := First_Formal (Proc);
+ -- Check that the type of controlling formals is derived from the
+ -- parent subprogram's controlling formal type (or designated type
+ -- if the formal type is an anonymous access type).
+
+ F1 := First_Formal (Parent_Subp);
F2 := First_Formal (Subp);
while Present (F1) and then Present (F2) loop
if Ekind (Etype (F1)) = E_Anonymous_Access_Type then
elsif Ekind (Etype (F2)) = E_Anonymous_Access_Type then
return False;
- elsif Etype (F1) /= Etype (F2) then
+ elsif Etype (F1) = Parent_Typ and then Etype (F2) /= Full then
return False;
end if;
Next_Formal (F2);
end loop;
+ -- Check that a controlling result type is derived from the parent
+ -- subprogram's result type (or designated type if the result type
+ -- is an anonymous access type).
+
+ if Ekind (Parent_Subp) = E_Function then
+ if Ekind (Subp) /= E_Function then
+ return False;
+
+ elsif Ekind (Etype (Parent_Subp)) = E_Anonymous_Access_Type then
+ if Ekind (Etype (Subp)) /= E_Anonymous_Access_Type then
+ return False;
+
+ elsif Designated_Type (Etype (Parent_Subp)) = Parent_Typ
+ and then Designated_Type (Etype (Subp)) /= Full
+ then
+ return False;
+ end if;
+
+ elsif Ekind (Etype (Subp)) = E_Anonymous_Access_Type then
+ return False;
+
+ elsif Etype (Parent_Subp) = Parent_Typ
+ and then Etype (Subp) /= Full
+ then
+ return False;
+ end if;
+
+ elsif Ekind (Subp) = E_Function then
+ return False;
+ end if;
+
return No (F1) and then No (F2);
end Derives_From;
if Derives_From (Node (Op1)) then
if No (Prev) then
- -- Avoid adding it to the list of primitives if already there!
+ -- Avoid adding it to the list of primitives if already there
if Node (Op2) /= Subp then
Prepend_Elmt (Subp, New_Prim);
if Present (Tagged_Type) and then Is_Tagged_Type (Tagged_Type) then
Append_Unique_Elmt (Old_Subp, Primitive_Operations (Tagged_Type));
- -- If Old_Subp isn't already marked as dispatching then
- -- this is the case of an operation of an untagged private
- -- type fulfilled by a tagged type that overrides an
- -- inherited dispatching operation, so we set the necessary
- -- dispatching attributes here.
+ -- If Old_Subp isn't already marked as dispatching then this is
+ -- the case of an operation of an untagged private type fulfilled
+ -- by a tagged type that overrides an inherited dispatching
+ -- operation, so we set the necessary dispatching attributes here.
if not Is_Dispatching_Operation (Old_Subp) then
-- If the untagged type has no discriminants, and the full
- -- view is constrained, there will be a spurious mismatch
- -- of subtypes on the controlling arguments, because the tagged
+ -- view is constrained, there will be a spurious mismatch of
+ -- subtypes on the controlling arguments, because the tagged
-- type is the internal base type introduced in the derivation.
-- Use the original type to verify conformance, rather than the
-- base type.
Check_Controlling_Formals (Tagged_Type, Old_Subp);
Set_Is_Dispatching_Operation (Old_Subp, True);
- Set_DT_Position (Old_Subp, No_Uint);
+ Set_DT_Position_Value (Old_Subp, No_Uint);
end if;
-- If the old subprogram is an explicit renaming of some other
then
Set_Alias (Old_Subp, Alias (Subp));
- -- The derived subprogram should inherit the abstractness
- -- of the parent subprogram (except in the case of a function
+ -- The derived subprogram should inherit the abstractness of
+ -- the parent subprogram (except in the case of a function
-- returning the type). This sets the abstractness properly
- -- for cases where a private extension may have inherited
- -- an abstract operation, but the full type is derived from
- -- a descendant type and inherits a nonabstract version.
+ -- for cases where a private extension may have inherited an
+ -- abstract operation, but the full type is derived from a
+ -- descendant type and inherits a nonabstract version.
if Etype (Subp) /= Tagged_Type then
Set_Is_Abstract_Subprogram
then
return Controlling_Argument (Orig_Node);
+ -- Type conversions are dynamically tagged if the target type, or its
+ -- designated type, are classwide. An interface conversion expands into
+ -- a dereference, so test must be performed on the original node.
+
+ elsif Nkind (Orig_Node) = N_Type_Conversion
+ and then Nkind (N) = N_Explicit_Dereference
+ and then Is_Controlling_Actual (N)
+ then
+ declare
+ Target_Type : constant Entity_Id :=
+ Entity (Subtype_Mark (Orig_Node));
+
+ begin
+ if Is_Class_Wide_Type (Target_Type) then
+ return N;
+
+ elsif Is_Access_Type (Target_Type)
+ and then Is_Class_Wide_Type (Designated_Type (Target_Type))
+ then
+ return N;
+
+ else
+ return Empty;
+ end if;
+ end;
+
-- Normal case
elsif Is_Controlling_Actual (N)
Ctrl_Type : Entity_Id;
begin
- if Present (DTC_Entity (Subp)) then
+ if Ekind_In (Subp, E_Function, E_Procedure)
+ and then Present (DTC_Entity (Subp))
+ then
return Scope (DTC_Entity (Subp));
-- For subprograms internally generated by derivations of tagged types
-- use the alias subprogram as a reference to locate the dispatching
- -- type of Subp
+ -- type of Subp.
elsif not Comes_From_Source (Subp)
and then Present (Alias (Subp))
return Empty;
end Find_Dispatching_Type;
+ --------------------------------------
+ -- Find_Hidden_Overridden_Primitive --
+ --------------------------------------
+
+ function Find_Hidden_Overridden_Primitive (S : Entity_Id) return Entity_Id
+ is
+ Tag_Typ : constant Entity_Id := Find_Dispatching_Type (S);
+ Elmt : Elmt_Id;
+ Orig_Prim : Entity_Id;
+ Prim : Entity_Id;
+ Vis_List : Elist_Id;
+
+ begin
+ -- This Ada 2012 rule applies only for type extensions or private
+ -- extensions, where the parent type is not in a parent unit, and
+ -- where an operation is never declared but still inherited.
+
+ if No (Tag_Typ)
+ or else not Is_Record_Type (Tag_Typ)
+ or else Etype (Tag_Typ) = Tag_Typ
+ or else In_Open_Scopes (Scope (Etype (Tag_Typ)))
+ then
+ return Empty;
+ end if;
+
+ -- Collect the list of visible ancestor of the tagged type
+
+ Vis_List := Visible_Ancestors (Tag_Typ);
+
+ Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
+ while Present (Elmt) loop
+ Prim := Node (Elmt);
+
+ -- Find an inherited hidden dispatching primitive with the name of S
+ -- and a type-conformant profile.
+
+ if Present (Alias (Prim))
+ and then Is_Hidden (Alias (Prim))
+ and then Find_Dispatching_Type (Alias (Prim)) /= Tag_Typ
+ and then Primitive_Names_Match (S, Prim)
+ and then Type_Conformant (S, Prim)
+ then
+ declare
+ Vis_Ancestor : Elmt_Id;
+ Elmt : Elmt_Id;
+
+ begin
+ -- The original corresponding operation of Prim must be an
+ -- operation of a visible ancestor of the dispatching type S,
+ -- and the original corresponding operation of S2 must be
+ -- visible.
+
+ Orig_Prim := Original_Corresponding_Operation (Prim);
+
+ if Orig_Prim /= Prim
+ and then Is_Immediately_Visible (Orig_Prim)
+ then
+ Vis_Ancestor := First_Elmt (Vis_List);
+ while Present (Vis_Ancestor) loop
+ Elmt :=
+ First_Elmt (Primitive_Operations (Node (Vis_Ancestor)));
+ while Present (Elmt) loop
+ if Node (Elmt) = Orig_Prim then
+ Set_Overridden_Operation (S, Prim);
+ Set_Alias (Prim, Orig_Prim);
+ return Prim;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ Next_Elmt (Vis_Ancestor);
+ end loop;
+ end if;
+ end;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ return Empty;
+ end Find_Hidden_Overridden_Primitive;
+
---------------------------------------
-- Find_Primitive_Covering_Interface --
---------------------------------------
(Tagged_Type : Entity_Id;
Iface_Prim : Entity_Id) return Entity_Id
is
- E : Entity_Id;
+ E : Entity_Id;
+ El : Elmt_Id;
begin
pragma Assert (Is_Interface (Find_Dispatching_Type (Iface_Prim))
or else (Present (Alias (Iface_Prim))
- and then
- Is_Interface
- (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
+ and then
+ Is_Interface
+ (Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
+
+ -- Search in the homonym chain. Done to speed up locating visible
+ -- entities and required to catch primitives associated with the partial
+ -- view of private types when processing the corresponding full view.
E := Current_Entity (Iface_Prim);
while Present (E) loop
E := Homonym (E);
end loop;
+ -- Search in the list of primitives of the type. Required to locate
+ -- the covering primitive if the covering primitive is not visible
+ -- (for example, non-visible inherited primitive of private type).
+
+ El := First_Elmt (Primitive_Operations (Tagged_Type));
+ while Present (El) loop
+ E := Node (El);
+
+ -- Keep separate the management of internal entities that link
+ -- primitives with interface primitives from tagged type primitives.
+
+ if No (Interface_Alias (E)) then
+ if Present (Alias (E)) then
+
+ -- This interface primitive has not been covered yet
+
+ if Alias (E) = Iface_Prim then
+ return E;
+
+ -- The covering primitive was inherited
+
+ elsif Overridden_Operation (Ultimate_Alias (E))
+ = Iface_Prim
+ then
+ return E;
+ end if;
+ end if;
+
+ -- Check if E covers the interface primitive (includes case in
+ -- which E is an inherited private primitive).
+
+ if Is_Interface_Conformant (Tagged_Type, Iface_Prim, E) then
+ return E;
+ end if;
+
+ -- Use the internal entity that links the interface primitive with
+ -- the covering primitive to locate the entity.
+
+ elsif Interface_Alias (E) = Iface_Prim then
+ return Alias (E);
+ end if;
+
+ Next_Elmt (El);
+ end loop;
+
+ -- Not found
+
return Empty;
end Find_Primitive_Covering_Interface;
+ ---------------------------
+ -- Inherited_Subprograms --
+ ---------------------------
+
+ function Inherited_Subprograms
+ (S : Entity_Id;
+ No_Interfaces : Boolean := False;
+ Interfaces_Only : Boolean := False) return Subprogram_List
+ is
+ Result : Subprogram_List (1 .. 6000);
+ -- 6000 here is intended to be infinity. We could use an expandable
+ -- table, but it would be awfully heavy, and there is no way that we
+ -- could reasonably exceed this value.
+
+ N : Int := 0;
+ -- Number of entries in Result
+
+ Parent_Op : Entity_Id;
+ -- Traverses the Overridden_Operation chain
+
+ procedure Store_IS (E : Entity_Id);
+ -- Stores E in Result if not already stored
+
+ --------------
+ -- Store_IS --
+ --------------
+
+ procedure Store_IS (E : Entity_Id) is
+ begin
+ for J in 1 .. N loop
+ if E = Result (J) then
+ return;
+ end if;
+ end loop;
+
+ N := N + 1;
+ Result (N) := E;
+ end Store_IS;
+
+ -- Start of processing for Inherited_Subprograms
+
+ begin
+ pragma Assert (not (No_Interfaces and Interfaces_Only));
+
+ if Present (S) and then Is_Dispatching_Operation (S) then
+
+ -- Deal with direct inheritance
+
+ if not Interfaces_Only then
+ Parent_Op := S;
+ loop
+ Parent_Op := Overridden_Operation (Parent_Op);
+ exit when No (Parent_Op)
+ or else
+ (No_Interfaces
+ and then
+ Is_Interface (Find_Dispatching_Type (Parent_Op)));
+
+ if Is_Subprogram_Or_Generic_Subprogram (Parent_Op) then
+ Store_IS (Parent_Op);
+ end if;
+ end loop;
+ end if;
+
+ -- Now deal with interfaces
+
+ if not No_Interfaces then
+ declare
+ Tag_Typ : Entity_Id;
+ Prim : Entity_Id;
+ Elmt : Elmt_Id;
+
+ begin
+ Tag_Typ := Find_Dispatching_Type (S);
+
+ if Is_Concurrent_Type (Tag_Typ) then
+ Tag_Typ := Corresponding_Record_Type (Tag_Typ);
+ end if;
+
+ -- Search primitive operations of dispatching type
+
+ if Present (Tag_Typ)
+ and then Present (Primitive_Operations (Tag_Typ))
+ then
+ Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
+ while Present (Elmt) loop
+ Prim := Node (Elmt);
+
+ -- The following test eliminates some odd cases in which
+ -- Ekind (Prim) is Void, to be investigated further ???
+
+ if not Is_Subprogram_Or_Generic_Subprogram (Prim) then
+ null;
+
+ -- For [generic] subprogram, look at interface alias
+
+ elsif Present (Interface_Alias (Prim))
+ and then Alias (Prim) = S
+ then
+ -- We have found a primitive covered by S
+
+ Store_IS (Interface_Alias (Prim));
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+ end if;
+ end;
+ end if;
+ end if;
+
+ return Result (1 .. N);
+ end Inherited_Subprograms;
+
---------------------------
-- Is_Dynamically_Tagged --
---------------------------
begin
if Nkind (N) = N_Error then
return False;
+
+ elsif Present (Find_Controlling_Arg (N)) then
+ return True;
+
+ -- Special cases: entities, and calls that dispatch on result
+
+ elsif Is_Entity_Name (N) then
+ return Is_Class_Wide_Type (Etype (N));
+
+ elsif Nkind (N) = N_Function_Call
+ and then Is_Class_Wide_Type (Etype (N))
+ then
+ return True;
+
+ -- Otherwise check whether call has controlling argument
+
else
- return Find_Controlling_Arg (N) /= Empty;
+ return False;
end if;
end Is_Dynamically_Tagged;
+ ---------------------------------
+ -- Is_Null_Interface_Primitive --
+ ---------------------------------
+
+ function Is_Null_Interface_Primitive (E : Entity_Id) return Boolean is
+ begin
+ return Comes_From_Source (E)
+ and then Is_Dispatching_Operation (E)
+ and then Ekind (E) = E_Procedure
+ and then Null_Present (Parent (E))
+ and then Is_Interface (Find_Dispatching_Type (E));
+ end Is_Null_Interface_Primitive;
+
+ -----------------------------------
+ -- Is_Inherited_Public_Operation --
+ -----------------------------------
+
+ function Is_Inherited_Public_Operation (Op : Entity_Id) return Boolean is
+ Prim : constant Entity_Id := Alias (Op);
+ Scop : constant Entity_Id := Scope (Prim);
+ Pack_Decl : Node_Id;
+
+ begin
+ if Comes_From_Source (Prim) and then Ekind (Scop) = E_Package then
+ Pack_Decl := Unit_Declaration_Node (Scop);
+ return Nkind (Pack_Decl) = N_Package_Declaration
+ and then List_Containing (Unit_Declaration_Node (Prim)) =
+ Visible_Declarations (Specification (Pack_Decl));
+
+ else
+ return False;
+ end if;
+ end Is_Inherited_Public_Operation;
+
--------------------------
-- Is_Tag_Indeterminate --
--------------------------
if not Has_Controlling_Result (Nam) then
return False;
+ -- The function may have a controlling result, but if the return type
+ -- is not visibly tagged, then this is not tag-indeterminate.
+
+ elsif Is_Access_Type (Etype (Nam))
+ and then not Is_Tagged_Type (Designated_Type (Etype (Nam)))
+ then
+ return False;
+
-- An explicit dereference means that the call has already been
-- expanded and there is no tag to propagate.
if Is_Controlling_Actual (Actual)
and then not Is_Tag_Indeterminate (Actual)
then
- return False; -- one operand is dispatching
+ -- One operand is dispatching
+
+ return False;
end if;
Next_Actual (Actual);
elsif Nkind (Orig_Node) = N_Attribute_Reference
and then
Get_Attribute_Id (Attribute_Name (Orig_Node)) = Attribute_Input
- and then
- Nkind (Prefix (Orig_Node)) /= N_Attribute_Reference
+ and then Nkind (Prefix (Orig_Node)) /= N_Attribute_Reference
then
return True;
- -- In Ada 2005 a function that returns an anonymous access type can
- -- dispatching, and the dereference of a call to such a function
- -- is also tag-indeterminate.
+ -- In Ada 2005, a function that returns an anonymous access type can be
+ -- dispatching, and the dereference of a call to such a function can
+ -- also be tag-indeterminate if the call itself is.
elsif Nkind (Orig_Node) = N_Explicit_Dereference
- and then Ada_Version >= Ada_05
+ and then Ada_Version >= Ada_2005
then
return Is_Tag_Indeterminate (Prefix (Orig_Node));
procedure Override_Dispatching_Operation
(Tagged_Type : Entity_Id;
Prev_Op : Entity_Id;
- New_Op : Entity_Id)
+ New_Op : Entity_Id;
+ Is_Wrapper : Boolean := False)
is
Elmt : Elmt_Id;
Prim : Node_Id;
begin
-- Diagnose failure to match No_Return in parent (Ada-2005, AI-414, but
- -- we do it unconditionally in Ada 95 now, since this is our pragma!)
+ -- we do it unconditionally in Ada 95 now, since this is our pragma).
if No_Return (Prev_Op) and then not No_Return (New_Op) then
Error_Msg_N ("procedure & must have No_Return pragma", New_Op);
-- was malformed, and an error must have been emitted already.
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
- while Present (Elmt)
- and then Node (Elmt) /= Prev_Op
- loop
+ while Present (Elmt) and then Node (Elmt) /= Prev_Op loop
Next_Elmt (Elmt);
end loop;
return;
end if;
- Replace_Elmt (Elmt, New_Op);
-
- if Ada_Version >= Ada_05
- and then Has_Interfaces (Tagged_Type)
+ -- The location of entities that come from source in the list of
+ -- primitives of the tagged type must follow their order of occurrence
+ -- in the sources to fulfill the C++ ABI. If the overridden entity is a
+ -- primitive of an interface that is not implemented by the parents of
+ -- this tagged type (that is, it is an alias of an interface primitive
+ -- generated by Derive_Interface_Progenitors), then we must append the
+ -- new entity at the end of the list of primitives.
+
+ if Present (Alias (Prev_Op))
+ and then Etype (Tagged_Type) /= Tagged_Type
+ and then Is_Interface (Find_Dispatching_Type (Alias (Prev_Op)))
+ and then not Is_Ancestor (Find_Dispatching_Type (Alias (Prev_Op)),
+ Tagged_Type, Use_Full_View => True)
+ and then not Implements_Interface
+ (Etype (Tagged_Type),
+ Find_Dispatching_Type (Alias (Prev_Op)))
then
+ Remove_Elmt (Primitive_Operations (Tagged_Type), Elmt);
+ Append_Elmt (New_Op, Primitive_Operations (Tagged_Type));
+
+ -- The new primitive replaces the overridden entity. Required to ensure
+ -- that overriding primitive is assigned the same dispatch table slot.
+
+ else
+ Replace_Elmt (Elmt, New_Op);
+ end if;
+
+ if Ada_Version >= Ada_2005 and then Has_Interfaces (Tagged_Type) then
+
-- Ada 2005 (AI-251): Update the attribute alias of all the aliased
- -- entities of the overridden primitive to reference New_Op, and also
- -- propagate the proper value of Is_Abstract_Subprogram. Verify
+ -- entities of the overridden primitive to reference New_Op, and
+ -- also propagate the proper value of Is_Abstract_Subprogram. Verify
-- that the new operation is subtype conformant with the interface
-- operations that it implements (for operations inherited from the
-- parent itself, this check is made when building the derived type).
- -- Note: This code is only executed in case of late overriding
+ -- Note: This code is executed with internally generated wrappers of
+ -- functions with controlling result and late overridings.
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
while Present (Elmt) loop
elsif Is_Subprogram (Prim)
and then Present (Interface_Alias (Prim))
and then Alias (Prim) = Prev_Op
- and then Present (Etype (New_Op))
then
Set_Alias (Prim, New_Op);
- Check_Subtype_Conformant (New_Op, Prim);
- Set_Is_Abstract_Subprogram (Prim,
- Is_Abstract_Subprogram (New_Op));
- -- Ensure that this entity will be expanded to fill the
- -- corresponding entry in its dispatch table.
+ -- No further decoration needed yet for internally generated
+ -- wrappers of controlling functions since (at this stage)
+ -- they are not yet decorated.
+
+ if not Is_Wrapper then
+ Check_Subtype_Conformant (New_Op, Prim);
+
+ Set_Is_Abstract_Subprogram (Prim,
+ Is_Abstract_Subprogram (New_Op));
- if not Is_Abstract_Subprogram (Prim) then
- Set_Has_Delayed_Freeze (Prim);
+ -- Ensure that this entity will be expanded to fill the
+ -- corresponding entry in its dispatch table.
+
+ if not Is_Abstract_Subprogram (Prim) then
+ Set_Has_Delayed_Freeze (Prim);
+ end if;
end if;
end if;
-- Make the overriding operation into an alias of the implicit one.
-- In this fashion a call from outside ends up calling the new body
- -- even if non-dispatching, and a call from inside calls the
- -- overriding operation because it hides the implicit one. To
- -- indicate that the body of Prev_Op is never called, set its
- -- dispatch table entity to Empty. If the overridden operation
- -- has a dispatching result, so does the overriding one.
+ -- even if non-dispatching, and a call from inside calls the over-
+ -- riding operation because it hides the implicit one. To indicate
+ -- that the body of Prev_Op is never called, set its dispatch table
+ -- entity to Empty. If the overridden operation has a dispatching
+ -- result, so does the overriding one.
Set_Alias (Prev_Op, New_Op);
Set_DTC_Entity (Prev_Op, Empty);
then
return;
+ -- When expansion is suppressed, an unexpanded call to 'Input can occur,
+ -- and in that case we can simply return.
+
+ elsif Nkind (Actual) = N_Attribute_Reference then
+ pragma Assert (Attribute_Name (Actual) = Name_Input);
+
+ return;
+
-- Only other possibilities are parenthesized or qualified expression,
-- or an expander-generated unchecked conversion of a function call to
-- a stream Input attribute.
Call_Node := Expression (Actual);
end if;
+ -- No action needed if the call has been already expanded
+
+ if Is_Expanded_Dispatching_Call (Call_Node) then
+ return;
+ end if;
+
-- Do not set the Controlling_Argument if already set. This happens in
-- the special case of _Input (see Exp_Attr, case Input).
end if;
Arg := First_Actual (Call_Node);
-
while Present (Arg) loop
if Is_Tag_Indeterminate (Arg) then
Propagate_Tag (Control, Arg);
-- and would have to undo any expansion to an indirect call.
if Tagged_Type_Expansion then
- Expand_Dispatching_Call (Call_Node);
+ declare
+ Call_Typ : constant Entity_Id := Etype (Call_Node);
+
+ begin
+ Expand_Dispatching_Call (Call_Node);
+
+ -- If the controlling argument is an interface type and the type
+ -- of Call_Node differs then we must add an implicit conversion to
+ -- force displacement of the pointer to the object to reference
+ -- the secondary dispatch table of the interface.
+
+ if Is_Interface (Etype (Control))
+ and then Etype (Control) /= Call_Typ
+ then
+ -- Cannot use Convert_To because the previous call to
+ -- Expand_Dispatching_Call leaves decorated the Call_Node
+ -- with the type of Control.
+
+ Rewrite (Call_Node,
+ Make_Type_Conversion (Sloc (Call_Node),
+ Subtype_Mark =>
+ New_Occurrence_Of (Etype (Control), Sloc (Call_Node)),
+ Expression => Relocate_Node (Call_Node)));
+ Set_Etype (Call_Node, Etype (Control));
+ Set_Analyzed (Call_Node);
+
+ Expand_Interface_Conversion (Call_Node);
+ end if;
+ end;
-- Expansion of a dispatching call results in an indirect call, which in
-- turn causes current values to be killed (see Resolve_Call), so on VM
git://gcc.gnu.org / gcc.git / blobdiff