-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2011, 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- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. 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, 51 Franklin Street, Fifth Floor, --
--- Boston, MA 02110-1301, USA. --
+-- Public License distributed with GNAT; see file COPYING3. If not, go to --
+-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
with Elists; use Elists;
with Einfo; use Einfo;
with Exp_Disp; use Exp_Disp;
-with Exp_Ch6; use Exp_Ch6;
+with Exp_Util; use Exp_Util;
with Exp_Ch7; use Exp_Ch7;
with Exp_Tss; use Exp_Tss;
with Errout; use Errout;
-with Hostparm; use Hostparm;
+with Lib.Xref; use Lib.Xref;
+with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Sem; use Sem;
+with Sem_Aux; use Sem_Aux;
+with Sem_Ch3; use Sem_Ch3;
with Sem_Ch6; use Sem_Ch6;
with Sem_Eval; use Sem_Eval;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Snames; use Snames;
-with Stand; use Stand;
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.
+
-------------------------------
-- Add_Dispatching_Operation --
-------------------------------
New_Op : Entity_Id)
is
List : constant Elist_Id := Primitive_Operations (Tagged_Type);
+
begin
- Append_Elmt (New_Op, List);
+ -- The dispatching operation may already be on the list, if it is the
+ -- wrapper for an inherited function of a null extension (see Exp_Ch3
+ -- for the construction of function wrappers). The list of primitive
+ -- operations must not contain duplicates.
+
+ 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 --
-------------------------------
begin
Formal := First_Formal (Subp);
-
while Present (Formal) loop
Ctrl_Type := Check_Controlling_Type (Etype (Formal), Subp);
if Present (Ctrl_Type) then
+
+ -- When controlling type is concurrent and declared within a
+ -- generic or inside an instance use corresponding record type.
+
+ if Is_Concurrent_Type (Ctrl_Type)
+ and then Present (Corresponding_Record_Type (Ctrl_Type))
+ then
+ Ctrl_Type := Corresponding_Record_Type (Ctrl_Type);
+ end if;
+
if Ctrl_Type = Typ then
Set_Is_Controlling_Formal (Formal);
- -- Ada 2005 (AI-231): Anonymous access types used in
+ -- Ada 2005 (AI-231): Anonymous access types that are used in
-- controlling parameters exclude null because it is necessary
-- to read the tag to dispatch, and null has no tag.
end if;
if Present (Default_Value (Formal)) then
- if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
+
+ -- In Ada 2005, access parameters can have defaults
+
+ if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
+ and then Ada_Version < Ada_2005
+ then
Error_Msg_N
("default not allowed for controlling access parameter",
Default_Value (Formal));
Next_Formal (Formal);
end loop;
- if Present (Etype (Subp)) then
+ if Ekind_In (Subp, E_Function, E_Generic_Function) then
Ctrl_Type := Check_Controlling_Type (Etype (Subp), Subp);
if Present (Ctrl_Type) then
Set_Has_Controlling_Result (Subp);
-- Check that result subtype statically matches first subtype
+ -- (Ada 2005): Subp may have a controlling access result.
+
+ if Subtypes_Statically_Match (Typ, Etype (Subp))
+ or else (Ekind (Etype (Subp)) = E_Anonymous_Access_Type
+ and then
+ Subtypes_Statically_Match
+ (Typ, Designated_Type (Etype (Subp))))
+ then
+ null;
- if not Subtypes_Statically_Match (Typ, Etype (Subp)) then
+ else
Error_Msg_N
("result subtype does not match controlling type", Subp);
end if;
Tagged_Type := Base_Type (Designated_Type (T));
end if;
- -- Ada 2005 : an incomplete type can be tagged. An operation with
- -- an access parameter of the type is dispatching.
+ -- Ada 2005: an incomplete type can be tagged. An operation with an
+ -- access parameter of the type is dispatching.
elsif Scope (Designated_Type (T)) = Current_Scope then
Tagged_Type := Designated_Type (T);
end if;
end if;
- if No (Tagged_Type)
- or else Is_Class_Wide_Type (Tagged_Type)
- then
+ if No (Tagged_Type) or else Is_Class_Wide_Type (Tagged_Type) then
return Empty;
- -- The dispatching type and the primitive operation must be defined
- -- in the same scope, except in the case of internal operations and
- -- formal abstract subprograms.
+ -- The dispatching type and the primitive operation must be defined in
+ -- the same scope, except in the case of internal operations and formal
+ -- abstract subprograms.
elsif ((Scope (Subp) = Scope (Tagged_Type) or else Is_Internal (Subp))
and then (not Is_Generic_Type (Tagged_Type)
----------------------------
procedure Check_Dispatching_Call (N : Node_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
Actual : Node_Id;
Formal : Entity_Id;
Control : Node_Id := Empty;
Func : Entity_Id;
Subp_Entity : Entity_Id;
- Loc : constant Source_Ptr := Sloc (N);
Indeterm_Ancestor_Call : Boolean := False;
Indeterm_Ctrl_Type : Entity_Id;
+ Static_Tag : Node_Id := Empty;
+ -- If a controlling formal has a statically tagged actual, the tag of
+ -- this actual is to be used for any tag-indeterminate actual.
+
+ procedure Check_Direct_Call;
+ -- In the case when the controlling actual is a class-wide type whose
+ -- root type's completion is a task or protected type, the call is in
+ -- fact direct. This routine detects the above case and modifies the
+ -- call accordingly.
+
procedure Check_Dispatching_Context;
-- If the call is tag-indeterminate and the entity being called is
-- abstract, verify that the context is a call that will eventually
-- provide a tag for dispatching, or has provided one already.
+ -----------------------
+ -- Check_Direct_Call --
+ -----------------------
+
+ procedure Check_Direct_Call is
+ Typ : Entity_Id := Etype (Control);
+
+ function Is_User_Defined_Equality (Id : Entity_Id) return Boolean;
+ -- Determine whether an entity denotes a user-defined equality
+
+ ------------------------------
+ -- Is_User_Defined_Equality --
+ ------------------------------
+
+ function Is_User_Defined_Equality (Id : Entity_Id) return Boolean is
+ begin
+ return
+ Ekind (Id) = E_Function
+ and then Chars (Id) = Name_Op_Eq
+ and then Comes_From_Source (Id)
+
+ -- Internally generated equalities have a full type declaration
+ -- as their parent.
+
+ and then Nkind (Parent (Id)) = N_Function_Specification;
+ end Is_User_Defined_Equality;
+
+ -- Start of processing for Check_Direct_Call
+
+ begin
+ -- Predefined primitives do not receive wrappers since they are built
+ -- from scratch for the corresponding record of synchronized types.
+ -- Equality is in general predefined, but is excluded from the check
+ -- when it is user-defined.
+
+ if Is_Predefined_Dispatching_Operation (Subp_Entity)
+ and then not Is_User_Defined_Equality (Subp_Entity)
+ then
+ return;
+ end if;
+
+ if Is_Class_Wide_Type (Typ) then
+ Typ := Root_Type (Typ);
+ end if;
+
+ if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then
+ Typ := Full_View (Typ);
+ end if;
+
+ if Is_Concurrent_Type (Typ)
+ and then
+ Present (Corresponding_Record_Type (Typ))
+ then
+ Typ := Corresponding_Record_Type (Typ);
+
+ -- The concurrent record's list of primitives should contain a
+ -- wrapper for the entity of the call, retrieve it.
+
+ declare
+ Prim : Entity_Id;
+ Prim_Elmt : Elmt_Id;
+ Wrapper_Found : Boolean := False;
+
+ begin
+ Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
+ while Present (Prim_Elmt) loop
+ Prim := Node (Prim_Elmt);
+
+ if Is_Primitive_Wrapper (Prim)
+ and then Wrapped_Entity (Prim) = Subp_Entity
+ then
+ Wrapper_Found := True;
+ exit;
+ end if;
+
+ Next_Elmt (Prim_Elmt);
+ end loop;
+
+ -- A primitive declared between two views should have a
+ -- corresponding wrapper.
+
+ pragma Assert (Wrapper_Found);
+
+ -- Modify the call by setting the proper entity
+
+ Set_Entity (Name (N), Prim);
+ end;
+ end if;
+ end Check_Direct_Call;
+
-------------------------------
-- Check_Dispatching_Context --
-------------------------------
and then not Is_Abstract_Subprogram (Alias (Subp))
and then No (DTC_Entity (Subp))
then
- -- Private overriding of inherited abstract operation,
- -- call is legal.
+ -- Private overriding of inherited abstract operation, call is
+ -- legal.
Set_Entity (Name (N), Alias (Subp));
return;
else
Par := Parent (N);
-
while Present (Par) loop
-
- if (Nkind (Par) = N_Function_Call or else
- Nkind (Par) = N_Procedure_Call_Statement or else
- Nkind (Par) = N_Assignment_Statement or else
- Nkind (Par) = N_Op_Eq or else
- Nkind (Par) = N_Op_Ne)
+ 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))
then
return;
-- Find a controlling argument, if any
if Present (Parameter_Associations (N)) then
- Actual := First_Actual (N);
-
Subp_Entity := Entity (Name (N));
- Formal := First_Formal (Subp_Entity);
+ Actual := First_Actual (N);
+ Formal := First_Formal (Subp_Entity);
while Present (Actual) loop
Control := Find_Controlling_Arg (Actual);
exit when Present (Control);
then
Indeterm_Ancestor_Call := True;
Indeterm_Ctrl_Type := Etype (Formal);
+
+ -- If the formal is controlling but the actual is not, the type
+ -- of the actual is statically known, and may be used as the
+ -- controlling tag for some other tag-indeterminate actual.
+
+ elsif Is_Controlling_Formal (Formal)
+ and then Is_Entity_Name (Actual)
+ and then Is_Tagged_Type (Etype (Actual))
+ then
+ Static_Tag := Actual;
end if;
Next_Actual (Actual);
Next_Formal (Formal);
end loop;
- -- 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 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.
+ -- 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
+ -- 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.
if No (Control)
and then Indeterm_Ancestor_Call
+ and then No (Static_Tag)
then
Control :=
Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Indeterm_Ctrl_Type, Loc),
Attribute_Name => Name_Tag);
+
Analyze (Control);
end if;
end if;
Actual := First_Actual (N);
-
while Present (Actual) loop
if Actual /= Control then
elsif Is_Tag_Indeterminate (Actual) then
- -- 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.
+ -- 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.
Propagate_Tag (Control, Actual);
Set_Controlling_Argument (N, Control);
Check_Restriction (No_Dispatching_Calls, N);
- -- Ada 2005 (AI-318-02): Check current implementation restriction
- -- that a dispatching call cannot be made to a primitive function
- -- with a limited result type. This restriction can be removed
- -- once calls to limited functions with class-wide results are
- -- supported. ???
+ -- The dispatching call may need to be converted into a direct
+ -- call in certain cases.
- if Ada_Version = Ada_05
- and then Nkind (N) = N_Function_Call
- then
- Func := Entity (Name (N));
+ Check_Direct_Call;
+
+ -- If there is a statically tagged actual and a tag-indeterminate
+ -- call to a function of the ancestor (such as that provided by a
+ -- default), then treat this as a dispatching call and propagate
+ -- the tag to the tag-indeterminate call(s).
- if Has_Controlling_Result (Func)
- and then Is_Limited_Type (Etype (Func))
+ elsif Present (Static_Tag) and then Indeterm_Ancestor_Call then
+ Control :=
+ Make_Attribute_Reference (Loc,
+ Prefix =>
+ New_Occurrence_Of (Etype (Static_Tag), Loc),
+ Attribute_Name => Name_Tag);
+
+ Analyze (Control);
+
+ Actual := First_Actual (N);
+ Formal := First_Formal (Subp_Entity);
+ while Present (Actual) loop
+ if Is_Tag_Indeterminate (Actual)
+ and then Is_Controlling_Formal (Formal)
then
- Error_Msg_N ("(Ada 2005) limited function call in this" &
- " context is not yet implemented", N);
+ Propagate_Tag (Control, Actual);
end if;
- end if;
+
+ Next_Actual (Actual);
+ Next_Formal (Formal);
+ end loop;
+
+ Check_Dispatching_Context;
else
-- The call is not dispatching, so check that there aren't any
-- tag-indeterminate abstract calls left.
Actual := First_Actual (N);
-
while Present (Actual) loop
if Is_Tag_Indeterminate (Actual) then
Func := Empty;
-- Only other possibility is a qualified expression whose
- -- consituent expression is itself a call.
+ -- constituent expression is itself a call.
else
Func :=
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;
-
- function Is_Visibly_Controlled (T : Entity_Id) return Boolean;
- -- Check whether T is derived from a visibly controlled type.
- -- This is true if the root type is declared in Ada.Finalization.
- -- If T is derived instead from a private type whose full view
- -- is controlled, an explicit Initialize/Adjust/Finalize subprogram
- -- does not override the inherited one.
-
- ---------------------------
- -- Is_Visibly_Controlled --
- ---------------------------
-
- function Is_Visibly_Controlled (T : Entity_Id) return Boolean is
- Root : constant Entity_Id := Root_Type (T);
- begin
- return Chars (Scope (Root)) = Name_Finalization
- and then Chars (Scope (Scope (Root))) = Name_Ada
- and then Scope (Scope (Scope (Root))) = Standard_Standard;
- end Is_Visibly_Controlled;
-
- -- Start of processing for Check_Dispatching_Operation
+ 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 be 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
+ Tagged_Type := Corresponding_Record_Type (Tagged_Type);
+ end if;
- if No (Corresponding_Record_Type (Tagged_Type)) then
- return;
- end if;
+ -- (AI-345): The task body procedure is not a primitive of the tagged
+ -- type
- Tagged_Type := Corresponding_Record_Type (Tagged_Type);
+ if Present (Tagged_Type)
+ and then Is_Concurrent_Record_Type (Tagged_Type)
+ and then Present (Corresponding_Concurrent_Type (Tagged_Type))
+ and then Is_Task_Type (Corresponding_Concurrent_Type (Tagged_Type))
+ and then Subp = Get_Task_Body_Procedure
+ (Corresponding_Concurrent_Type (Tagged_Type))
+ then
+ return;
end if;
-- If Subp is derived from a dispatching operation then it should
begin
E := First_Entity (Subp);
while Present (E) loop
- if Is_Access_Type (Etype (E)) then
+
+ -- For an access parameter, check designated type
+
+ if Ekind (Etype (E)) = E_Anonymous_Access_Type then
Typ := Designated_Type (Etype (E));
else
Typ := Etype (E);
end if;
- if not Is_Class_Wide_Type (Typ)
+ 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_NE
+ Error_Msg_NE -- CODEFIX??
("\spec should appear immediately after declaration of &!",
Subp, Typ);
exit;
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_NE
return;
-- The subprograms build internally after the freezing point (such as
- -- the Init procedure) are not primitives
+ -- init procs, interface thunks, type support subprograms, and Offset
+ -- to top functions for accessing interface components in variable
+ -- size tagged types) are not primitives.
elsif Is_Frozen (Tagged_Type)
and then not Comes_From_Source (Subp)
and then not Has_Dispatching_Parent
then
+ -- Complete decoration of internally built subprograms that override
+ -- a dispatching primitive. These entities correspond with the
+ -- following cases:
+
+ -- 1. Ada 2005 (AI-391): Wrapper functions built by the expander
+ -- to override functions of nonabstract null extensions. These
+ -- primitives were added to the list of primitives of the tagged
+ -- type by Make_Controlling_Function_Wrappers. However, attribute
+ -- Is_Dispatching_Operation must be set to true.
+
+ -- 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 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
+ (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;
+
return;
-- The operation may be a child unit, whose scope is the defining
null;
-- If the type is already frozen, the overriding is not allowed
- -- except when Old_Subp is not a dispatching operation (which
- -- can occur when Old_Subp was inherited by an untagged type).
- -- However, a body with no previous spec freezes the type "after"
- -- its declaration, and therefore is a legal overriding (unless
- -- the type has already been frozen). Only the first such body
- -- is legal.
+ -- except when Old_Subp is not a dispatching operation (which can
+ -- occur when Old_Subp was inherited by an untagged type). However,
+ -- a body with no previous spec freezes the type *after* its
+ -- declaration, and therefore is a legal overriding (unless the type
+ -- has already been frozen). Only the first such body is legal.
elsif Present (Old_Subp)
and then Is_Dispatching_Operation (Old_Subp)
then
declare
Subp_Body : constant Node_Id := Unit_Declaration_Node (Subp);
- Decl_Item : Node_Id := Next (Parent (Tagged_Type));
+ Decl_Item : Node_Id;
begin
-- ??? The checks here for whether the type has been
-- 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 then the type has been
- -- frozen already so the overriding primitive is
- -- illegal.
+ -- Look at each declaration following the type up until the
+ -- new subprogram body. If any of the declarations is a body
+ -- then the type has been frozen already so the overriding
+ -- primitive is illegal.
+ Decl_Item := Next (Parent (Tagged_Type));
while Present (Decl_Item)
and then (Decl_Item /= Subp_Body)
loop
end loop;
-- If the subprogram doesn't follow in the list of
- -- declarations including the type then the type
- -- has definitely been frozen already and the body
- -- is illegal.
+ -- declarations including the type then the type has
+ -- definitely been frozen already and the body is illegal.
if No (Decl_Item) then
Error_Msg_N ("overriding of& is too late!", Subp);
-- 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
+ -- references to other primitives were already created
+ -- when type was frozen.
Body_Is_Last_Primitive := True;
Set_DT_Position (Subp, DT_Position (Old_Subp));
if not Restriction_Active (No_Dispatching_Calls) then
- Insert_After (Subp_Body,
- Fill_DT_Entry (Sloc (Subp_Body), Subp));
+ if Building_Static_DT (Tagged_Type) then
+
+ -- If the static dispatch table has not been
+ -- built then there is nothing else to do now;
+ -- otherwise we notify that we cannot build the
+ -- static dispatch table.
+
+ if Has_Dispatch_Table (Tagged_Type) then
+ Error_Msg_N
+ ("overriding of& is too late for building" &
+ " static dispatch tables!", Subp);
+ Error_Msg_N
+ ("\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),
+ Prim => Subp));
+ end if;
+
+ -- Indicate that this is an overriding operation,
+ -- and replace the overridden entry in the list of
+ -- primitive operations, which is used for xref
+ -- generation subsequently.
+
+ Generate_Reference (Tagged_Type, Subp, 'P', False);
+ Override_Dispatching_Operation
+ (Tagged_Type, Old_Subp, Subp);
end if;
end if;
end if;
Subp);
end if;
- -- If the type is not frozen yet and we are not in the overridding
+ -- 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.
-
- elsif not Is_Frozen (Tagged_Type) then
+ -- operation, which requires the declaration to be in a package spec
+ -- (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);
return;
end if;
-- Now, we are sure that the scope is a package spec. If the subprogram
- -- is declared after the freezing point ot the type that's an error
+ -- is declared after the freezing point of the type that's an error
elsif Is_Frozen (Tagged_Type) and then not Has_Dispatching_Parent then
Error_Msg_N ("this primitive operation is declared too late", Subp);
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
+
+ if No (Ovr_Subp)
+ and then Ada_Version >= Ada_2012
+ then
+ Ovr_Subp := Find_Hidden_Overridden_Primitive (Subp);
+ end if;
+
-- Now it should be a correct primitive operation, put it in the list
- if Present (Old_Subp) then
- Check_Subtype_Conformant (Subp, Old_Subp);
+ 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, Ovr_Subp);
+
if (Chars (Subp) = Name_Initialize
or else Chars (Subp) = Name_Adjust
or else Chars (Subp) = Name_Finalize)
and then Is_Controlled (Tagged_Type)
and then not Is_Visibly_Controlled (Tagged_Type)
then
- Set_Is_Overriding_Operation (Subp, False);
- Error_Msg_NE
- ("operation does not override inherited&?", Subp, Subp);
+ Set_Overridden_Operation (Subp, Empty);
+
+ -- If the subprogram specification carries an overriding
+ -- indicator, no need for the warning: it is either redundant,
+ -- or else an error will be reported.
+
+ if Nkind (Parent (Subp)) = N_Procedure_Specification
+ and then
+ (Must_Override (Parent (Subp))
+ or else Must_Not_Override (Parent (Subp)))
+ then
+ null;
+
+ -- Here we need the warning
+
+ else
+ Error_Msg_NE
+ ("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.
-
- 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 Full_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 (Abstract_Interface_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
- Register_Interface_DT_Entry (Subp_Body, Prim);
+ Insert_Actions_After (Subp_Body,
+ Register_Primitive (Sloc (Subp_Body), Prim => Prim));
end if;
Next_Elmt (Elmt);
end loop;
- -- Redisplay the contents of the updated dispatch table.
+ -- Redisplay the contents of the updated dispatch table
if Debug_Flag_ZZ then
Write_Str ("Late overriding: ");
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.
Set_Is_Dispatching_Operation (Subp, True);
+ -- Ada 2005 (AI-251): If the type implements interfaces we must check
+ -- subtype conformance against all the interfaces covered by this
+ -- primitive.
+
+ if Present (Ovr_Subp)
+ and then Has_Interfaces (Tagged_Type)
+ then
+ declare
+ Ifaces_List : Elist_Id;
+ Iface_Elmt : Elmt_Id;
+ Iface_Prim_Elmt : Elmt_Id;
+ Iface_Prim : Entity_Id;
+ Ret_Typ : Entity_Id;
+
+ begin
+ Collect_Interfaces (Tagged_Type, Ifaces_List);
+
+ Iface_Elmt := First_Elmt (Ifaces_List);
+ while Present (Iface_Elmt) loop
+ if not Is_Ancestor (Node (Iface_Elmt), Tagged_Type) then
+ Iface_Prim_Elmt :=
+ First_Elmt (Primitive_Operations (Node (Iface_Elmt)));
+ while Present (Iface_Prim_Elmt) loop
+ Iface_Prim := Node (Iface_Prim_Elmt);
+
+ if Is_Interface_Conformant
+ (Tagged_Type, Iface_Prim, Subp)
+ then
+ -- Handle procedures, functions whose return type
+ -- matches, or functions not returning interfaces
+
+ if Ekind (Subp) = E_Procedure
+ or else Etype (Iface_Prim) = Etype (Subp)
+ or else not Is_Interface (Etype (Iface_Prim))
+ then
+ Check_Subtype_Conformant
+ (New_Id => Subp,
+ Old_Id => Iface_Prim,
+ Err_Loc => Subp,
+ Skip_Controlling_Formals => True);
+
+ -- Handle functions returning interfaces
+
+ elsif Implements_Interface
+ (Etype (Subp), Etype (Iface_Prim))
+ then
+ -- Temporarily force both entities to return the
+ -- same type. Required because Subtype_Conformant
+ -- does not handle this case.
+
+ Ret_Typ := Etype (Iface_Prim);
+ Set_Etype (Iface_Prim, Etype (Subp));
+
+ Check_Subtype_Conformant
+ (New_Id => Subp,
+ Old_Id => Iface_Prim,
+ Err_Loc => Subp,
+ Skip_Controlling_Formals => True);
+
+ Set_Etype (Iface_Prim, Ret_Typ);
+ end if;
+ end if;
+
+ Next_Elmt (Iface_Prim_Elmt);
+ end loop;
+ end if;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end;
+ end if;
+
if not Body_Is_Last_Primitive then
Set_DT_Position (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)
+ (Chars (Subp) = Name_Initialize or else
+ Chars (Subp) = Name_Adjust or else
+ Chars (Subp) = Name_Finalize or else
+ Chars (Subp) = 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 analyzed when the type was frozen. This requires
- -- removing the body of the redefined primitive, as well as
- -- its specification if needed (there is no spec created for
- -- Deep_Initialize, see exp_ch3.adb). We must also dismantle
- -- the exception information that may have been generated for
- -- it when front end zero-cost tables are enabled.
+ -- Remove previous controlled function which was constructed and
+ -- analyzed when the type was frozen. This requires removing the
+ -- body of the redefined primitive, as well as its specification
+ -- if needed (there is no spec created for Deep_Initialize, see
+ -- exp_ch3.adb). We must also dismantle the exception information
+ -- that may have been generated for it when front end zero-cost
+ -- tables are enabled.
for J in D_Names'Range loop
Old_P := TSS (Tagged_Type, D_Names (J));
Build_Late_Proc (Tagged_Type, Chars (Subp));
- -- The new operation is added to the actions of the freeze
- -- node for the type, but this node has already been analyzed,
- -- so we must retrieve and analyze explicitly the new body.
+ -- The new operation is added to the actions of the freeze node
+ -- for the type, but this node has already been analyzed, so we
+ -- must retrieve and analyze explicitly the new body.
if Present (F_Node)
and then Present (Actions (F_Node))
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);
- F2 := First_Formal (Subp);
+ -- 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
-
if Ekind (Etype (F2)) /= E_Anonymous_Access_Type then
return False;
-
elsif Designated_Type (Etype (F1)) = Parent_Typ
and then Designated_Type (Etype (F2)) /= Full
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;
Op1 := First_Elmt (Old_Prim);
Op2 := First_Elmt (New_Prim);
-
while Present (Op1) and then Present (Op2) loop
-
if Derives_From (Node (Op1)) then
-
if No (Prev) then
- Prepend_Elmt (Subp, New_Prim);
+
+ -- Avoid adding it to the list of primitives if already there!
+
+ if Node (Op2) /= Subp then
+ Prepend_Elmt (Subp, New_Prim);
+ end if;
+
else
Insert_Elmt_After (Subp, Prev);
end if;
Set_Scope (Subp, Current_Scope);
Tagged_Type := Find_Dispatching_Type (Subp);
+ -- Add Old_Subp to primitive operations if not already present
+
if Present (Tagged_Type) and then Is_Tagged_Type (Tagged_Type) then
- Append_Elmt (Old_Subp, Primitive_Operations (Tagged_Type));
+ 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.
then
declare
Formal : Entity_Id;
+
begin
Formal := First_Formal (Old_Subp);
while Present (Formal) loop
-- Otherwise, update its alias and other attributes.
if Present (Alias (Old_Subp))
- and then Nkind (Unit_Declaration_Node (Old_Subp))
- /= N_Subprogram_Renaming_Declaration
+ and then Nkind (Unit_Declaration_Node (Old_Subp)) /=
+ N_Subprogram_Renaming_Declaration
then
Set_Alias (Old_Subp, Alias (Subp));
return Find_Controlling_Arg (Expression (Orig_Node));
end if;
- -- Dispatching on result case
+ -- Dispatching on result case. If expansion is disabled, the node still
+ -- has the structure of a function call. However, if the function name
+ -- is an operator and the call was given in infix form, the original
+ -- node has no controlling result and we must examine the current node.
- if Nkind (Orig_Node) = N_Function_Call
+ if Nkind (N) = N_Function_Call
+ and then Present (Controlling_Argument (N))
+ and then Has_Controlling_Result (Entity (Name (N)))
+ then
+ return Controlling_Argument (N);
+
+ -- If expansion is enabled, the call may have been transformed into
+ -- an indirect call, and we need to recover the original node.
+
+ elsif Nkind (Orig_Node) = N_Function_Call
and then Present (Controlling_Argument (Orig_Node))
and then Has_Controlling_Result (Entity (Name (Orig_Node)))
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)
Typ := Etype (N);
if Is_Access_Type (Typ) then
- -- In the case of an Access attribute, use the type of
- -- the prefix, since in the case of an actual for an
- -- access parameter, the attribute's type may be of a
- -- specific designated type, even though the prefix
- -- type is class-wide.
+
+ -- In the case of an Access attribute, use the type of the prefix,
+ -- since in the case of an actual for an access parameter, the
+ -- attribute's type may be of a specific designated type, even
+ -- though the prefix type is class-wide.
if Nkind (N) = N_Attribute_Reference then
Typ := Etype (Prefix (N));
- -- An allocator is dispatching if the type of qualified
- -- expression is class_wide, in which case this is the
- -- controlling type.
+ -- An allocator is dispatching if the type of qualified expression
+ -- is class_wide, in which case this is the controlling type.
elsif Nkind (Orig_Node) = N_Allocator
and then Nkind (Expression (Orig_Node)) = N_Qualified_Expression
then
Typ := Etype (Expression (Orig_Node));
-
else
Typ := Designated_Type (Typ);
end if;
---------------------------
function Find_Dispatching_Type (Subp : Entity_Id) return Entity_Id is
+ A_Formal : Entity_Id;
Formal : Entity_Id;
Ctrl_Type : Entity_Id;
if 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.
+
+ elsif not Comes_From_Source (Subp)
+ and then Present (Alias (Subp))
+ and then Is_Dispatching_Operation (Alias (Subp))
+ then
+ if Ekind (Alias (Subp)) = E_Function
+ and then Has_Controlling_Result (Alias (Subp))
+ then
+ return Check_Controlling_Type (Etype (Subp), Subp);
+
+ else
+ Formal := First_Formal (Subp);
+ A_Formal := First_Formal (Alias (Subp));
+ while Present (A_Formal) loop
+ if Is_Controlling_Formal (A_Formal) then
+ return Check_Controlling_Type (Etype (Formal), Subp);
+ end if;
+
+ Next_Formal (Formal);
+ Next_Formal (A_Formal);
+ end loop;
+
+ pragma Assert (False);
+ return Empty;
+ end if;
+
+ -- General case
+
else
Formal := First_Formal (Subp);
while Present (Formal) loop
Next_Formal (Formal);
end loop;
- -- The subprogram may also be dispatching on result
+ -- The subprogram may also be dispatching on result
if Present (Etype (Subp)) then
- Ctrl_Type := Check_Controlling_Type (Etype (Subp), Subp);
-
- if Present (Ctrl_Type) then
- return Ctrl_Type;
- end if;
+ return Check_Controlling_Type (Etype (Subp), Subp);
end if;
end if;
+ pragma Assert (not Is_Dispatching_Operation (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 is valid only for type extensions or private
+ -- extensions.
+
+ if No (Tag_Typ)
+ or else not Is_Record_Type (Tag_Typ)
+ or else Etype (Tag_Typ) = 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 --
+ ---------------------------------------
+
+ function Find_Primitive_Covering_Interface
+ (Tagged_Type : Entity_Id;
+ Iface_Prim : Entity_Id) return Entity_Id
+ is
+ 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)))));
+
+ -- 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
+ if Is_Subprogram (E)
+ and then Is_Dispatching_Operation (E)
+ and then Is_Interface_Conformant (Tagged_Type, Iface_Prim, E)
+ then
+ return E;
+ end if;
+
+ 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) 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
+ if Present (S) and then Is_Dispatching_Operation (S) then
+
+ -- Deal with direct inheritance
+
+ Parent_Op := S;
+ loop
+ Parent_Op := Overridden_Operation (Parent_Op);
+ exit when No (Parent_Op);
+
+ if Is_Subprogram (Parent_Op)
+ or else Is_Generic_Subprogram (Parent_Op)
+ then
+ Store_IS (Parent_Op);
+ end if;
+ end loop;
+
+ -- Now deal with interfaces
+
+ 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 (Prim)
+ or else
+ Is_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;
+
+ return Result (1 .. N);
+ end Inherited_Subprograms;
+
---------------------------
-- Is_Dynamically_Tagged --
---------------------------
function Is_Dynamically_Tagged (N : Node_Id) return Boolean is
begin
- return Find_Controlling_Arg (N) /= Empty;
+ if Nkind (N) = N_Error then
+ return False;
+ else
+ return Find_Controlling_Arg (N) /= Empty;
+ 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_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);
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));
return;
end if;
- Replace_Elmt (Elmt, New_Op);
+ -- 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_05
- and then Has_Abstract_Interfaces (Tagged_Type)
+ 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 overriden primitive to reference New_Op, and also
- -- propagate them the new value of the attribute
- -- Is_Abstract_Subprogram.
+ -- 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
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
while Present (Elmt) loop
if Prim = New_Op then
null;
- elsif Present (Abstract_Interface_Alias (Prim))
+ -- Note: The check on Is_Subprogram protects the frontend against
+ -- reading attributes in entities that are not yet fully decorated
+
+ 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);
- Set_Is_Abstract_Subprogram
- (Prim, Is_Abstract_Subprogram (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.
-- 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.
+ -- 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);
+ Set_Has_Controlling_Result (New_Op, Has_Controlling_Result (Prev_Op));
return;
end if;
end Override_Dispatching_Operation;
elsif Nkind (Actual) = N_Identifier
and then Nkind (Original_Node (Actual)) = N_Function_Call
then
- -- Call rewritten as object declaration when stack-checking
- -- is enabled. Propagate tag to expression in declaration, which
- -- is original call.
+ -- Call rewritten as object declaration when stack-checking is
+ -- enabled. Propagate tag to expression in declaration, which is
+ -- original call.
Call_Node := Expression (Parent (Entity (Actual)));
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;
- -- Do not set the Controlling_Argument if already set. This happens
- -- in the special case of _Input (see Exp_Attr, case Input).
+ -- Do not set the Controlling_Argument if already set. This happens in
+ -- the special case of _Input (see Exp_Attr, case Input).
if No (Controlling_Argument (Call_Node)) then
Set_Controlling_Argument (Call_Node, Control);
end if;
Arg := First_Actual (Call_Node);
-
while Present (Arg) loop
if Is_Tag_Indeterminate (Arg) then
Propagate_Tag (Control, Arg);
Next_Actual (Arg);
end loop;
- -- Expansion of dispatching calls is suppressed when Java_VM, because
- -- the JVM back end directly handles the generation of dispatching
- -- calls and would have to undo any expansion to an indirect call.
+ -- Expansion of dispatching calls is suppressed when VM_Target, because
+ -- the VM back-ends directly handle the generation of dispatching calls
+ -- and would have to undo any expansion to an indirect call.
+
+ if Tagged_Type_Expansion then
+ 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 not Java_VM then
- Expand_Dispatching_Call (Call_Node);
+ 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, Is_Static => False);
+ 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
+ -- targets we do the call here to ensure consistent warnings between VM
+ -- and non-VM targets.
+
+ else
+ Kill_Current_Values;
end if;
end Propagate_Tag;
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