-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2005 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2007, 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 Atree; use Atree;
-with Checks; use Checks;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch8; use Sem_Ch8;
+with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
-- arguments, list possible interpretations.
procedure Analyze_One_Call
- (N : Node_Id;
- Nam : Entity_Id;
- Report : Boolean;
- Success : out Boolean);
+ (N : Node_Id;
+ Nam : Entity_Id;
+ Report : Boolean;
+ Success : out Boolean;
+ Skip_First : Boolean := False);
-- Check one interpretation of an overloaded subprogram name for
-- compatibility with the types of the actuals in a call. If there is a
-- single interpretation which does not match, post error if Report is
-- subprogram type constructed for an access_to_subprogram. If the actuals
-- are compatible with Nam, then Nam is added to the list of candidate
-- interpretations for N, and Success is set to True.
+ --
+ -- The flag Skip_First is used when analyzing a call that was rewritten
+ -- from object notation. In this case the first actual may have to receive
+ -- an explicit dereference, depending on the first formal of the operation
+ -- being called. The caller will have verified that the object is legal
+ -- for the call. If the remaining parameters match, the first parameter
+ -- will rewritten as a dereference if needed, prior to completing analysis.
procedure Check_Misspelled_Selector
(Prefix : Entity_Id;
-- a valid pair for the given operator, and record the corresponding
-- interpretation of the operator node. The node N may be an operator
-- node (the usual case) or a function call whose prefix is an operator
- -- designator. In both cases Op_Id is the operator name itself.
+ -- designator. In both cases Op_Id is the operator name itself.
procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
-- Give detailed information on overloaded call where none of the
-- operation is not a candidate interpretation.
function Try_Indexed_Call
- (N : Node_Id;
- Nam : Entity_Id;
- Typ : Entity_Id) return Boolean;
- -- If a function has defaults for all its actuals, a call to it may
- -- in fact be an indexing on the result of the call. Try_Indexed_Call
- -- attempts the interpretation as an indexing, prior to analysis as
- -- a call. If both are possible, the node is overloaded with both
- -- interpretations (same symbol but two different types).
+ (N : Node_Id;
+ Nam : Entity_Id;
+ Typ : Entity_Id;
+ Skip_First : Boolean) return Boolean;
+ -- If a function has defaults for all its actuals, a call to it may in fact
+ -- be an indexing on the result of the call. Try_Indexed_Call attempts the
+ -- interpretation as an indexing, prior to analysis as a call. If both are
+ -- possible, the node is overloaded with both interpretations (same symbol
+ -- but two different types). If the call is written in prefix form, the
+ -- prefix becomes the first parameter in the call, and only the remaining
+ -- actuals must be checked for the presence of defaults.
function Try_Indirect_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id) return Boolean;
- -- Similarly, a function F that needs no actuals can return an access
- -- to a subprogram, and the call F (X) interpreted as F.all (X). In
- -- this case the call may be overloaded with both interpretations.
+ -- Similarly, a function F that needs no actuals can return an access to a
+ -- subprogram, and the call F (X) interpreted as F.all (X). In this case
+ -- the call may be overloaded with both interpretations.
function Try_Object_Operation (N : Node_Id) return Boolean;
- -- Ada 2005 (AI-252): Give support to the object operation notation
+ -- Ada 2005 (AI-252): Support the object.operation notation
------------------------
-- Ambiguous_Operands --
-- Start of processing for Ambiguous_Operands
begin
- if Nkind (N) = N_In
- or else Nkind (N) = N_Not_In
- then
+ if Nkind (N) in N_Membership_Test then
Error_Msg_N ("ambiguous operands for membership", N);
elsif Nkind (N) = N_Op_Eq
procedure Analyze_Allocator (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Sav_Errs : constant Nat := Serious_Errors_Detected;
- E : Node_Id := Expression (N);
+ E : Node_Id := Expression (N);
Acc_Type : Entity_Id;
Type_Id : Entity_Id;
Check_Restriction (No_Allocators, N);
if Nkind (E) = N_Qualified_Expression then
+
Acc_Type := Create_Itype (E_Allocator_Type, N);
Set_Etype (Acc_Type, Acc_Type);
Init_Size_Align (Acc_Type);
Find_Type (Subtype_Mark (E));
- Type_Id := Entity (Subtype_Mark (E));
- Check_Fully_Declared (Type_Id, N);
+
+ -- Analyze the qualified expression, and apply the name resolution
+ -- rule given in 4.7 (3).
+
+ Analyze (E);
+ Type_Id := Etype (E);
Set_Directly_Designated_Type (Acc_Type, Type_Id);
+ Resolve (Expression (E), Type_Id);
+
if Is_Limited_Type (Type_Id)
and then Comes_From_Source (N)
and then not In_Instance_Body
then
- -- Ada 2005 (AI-287): Do not post an error if the expression
- -- corresponds to a limited aggregate. Limited aggregates
- -- are checked in sem_aggr in a per-component manner
- -- (compare with handling of Get_Value subprogram).
-
- if Ada_Version >= Ada_05
- and then Nkind (Expression (E)) = N_Aggregate
- then
- null;
- else
+ if not OK_For_Limited_Init (Expression (E)) then
Error_Msg_N ("initialization not allowed for limited types", N);
Explain_Limited_Type (Type_Id, N);
end if;
end if;
- Analyze_And_Resolve (Expression (E), Type_Id);
-
-- A qualified expression requires an exact match of the type,
-- class-wide matching is not allowed.
- if Is_Class_Wide_Type (Type_Id)
- and then Base_Type (Etype (Expression (E))) /= Base_Type (Type_Id)
- then
- Wrong_Type (Expression (E), Type_Id);
- end if;
+ -- if Is_Class_Wide_Type (Type_Id)
+ -- and then Base_Type
+ -- (Etype (Expression (E))) /= Base_Type (Type_Id)
+ -- then
+ -- Wrong_Type (Expression (E), Type_Id);
+ -- end if;
Check_Non_Static_Context (Expression (E));
Set_Etype (E, Type_Id);
- -- Case where no qualified expression is present
+ -- Case where allocator has a subtype indication
else
declare
end;
end if;
- if Is_Abstract (Type_Id) then
+ if Is_Abstract_Type (Type_Id) then
Error_Msg_N ("cannot allocate abstract object", E);
end if;
Check_Restriction (No_Local_Allocators, N);
end if;
- -- Ada 2005 (AI-231): Static checks
-
- if Ada_Version >= Ada_05
- and then (Null_Exclusion_Present (N)
- or else Can_Never_Be_Null (Etype (N)))
- then
- Null_Exclusion_Static_Checks (N);
- end if;
-
if Serious_Errors_Detected > Sav_Errs then
Set_Error_Posted (N);
Set_Etype (N, Any_Type);
Analyze_One_Call (N, Nam_Ent, True, Success);
+ -- If this is an indirect call, the return type of the access_to
+ -- subprogram may be an incomplete type. At the point of the call,
+ -- use the full type if available, and at the same time update
+ -- the return type of the access_to_subprogram.
+
+ if Success
+ and then Nkind (Nam) = N_Explicit_Dereference
+ and then Ekind (Etype (N)) = E_Incomplete_Type
+ and then Present (Full_View (Etype (N)))
+ then
+ Set_Etype (N, Full_View (Etype (N)));
+ Set_Etype (Nam_Ent, Etype (N));
+ end if;
+
else
-- An overloaded selected component must denote overloaded
-- operations of a concurrent type. The interpretations are
elsif not Is_Overloaded (N)
and then Is_Entity_Name (Nam)
then
- -- Resolution yields a single interpretation. Verify that
- -- is has the proper capitalization.
+ -- Resolution yields a single interpretation. Verify that the
+ -- reference has capitalization consistent with the declaration.
Set_Entity_With_Style_Check (Nam, Entity (Nam));
Generate_Reference (Entity (Nam), Nam);
End_Interp_List;
end if;
+
+ -- Check for not-yet-implemented cases of AI-318. We only need to check
+ -- for inherently limited types, because other limited types will be
+ -- returned by copy, which works just fine.
+ -- If the context is an attribute reference 'Class, this is really a
+ -- type conversion, which is illegal, and will be caught elsewhere.
+
+ if Ada_Version >= Ada_05
+ and then not Debug_Flag_Dot_L
+ and then Is_Inherently_Limited_Type (Etype (N))
+ and then (Nkind (Parent (N)) = N_Selected_Component
+ or else Nkind (Parent (N)) = N_Indexed_Component
+ or else Nkind (Parent (N)) = N_Slice
+ or else
+ (Nkind (Parent (N)) = N_Attribute_Reference
+ and then Attribute_Name (Parent (N)) /= Name_Class))
+ then
+ Error_Msg_N ("(Ada 2005) limited function call in this context" &
+ " is not yet implemented", N);
+ end if;
end Analyze_Call;
---------------------------
Analyze_Expression (L);
Analyze_Expression (R);
- -- If the entity is present, the node appears in an instance,
- -- and denotes a predefined concatenation operation. The resulting
- -- type is obtained from the arguments when possible. If the arguments
- -- are aggregates, the array type and the concatenation type must be
+ -- If the entity is present, the node appears in an instance, and
+ -- denotes a predefined concatenation operation. The resulting type is
+ -- obtained from the arguments when possible. If the arguments are
+ -- aggregates, the array type and the concatenation type must be
-- visible.
if Present (Op_Id) then
and then Nkind (N) = N_Op_Ne
then
Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
-
while Present (Op_Id) loop
-
if Ekind (Op_Id) = E_Operator then
Find_Equality_Types (L, R, Op_Id, N);
else
Make_Op_Not (Loc,
Right_Opnd =>
Make_Op_Eq (Loc,
- Left_Opnd => Relocate_Node (Left_Opnd (N)),
- Right_Opnd => Relocate_Node (Right_Opnd (N)))));
+ Left_Opnd => Left_Opnd (N),
+ Right_Opnd => Right_Opnd (N))));
Set_Entity (Right_Opnd (N), Op_Id);
Analyze (N);
else
Get_First_Interp (N, I, It);
-
while Present (It.Nam) loop
if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
if not Is_Overloaded (P) then
if Is_Access_Type (Etype (P)) then
- -- Set the Etype. We need to go thru Is_For_Access_Subtypes
- -- to avoid other problems caused by the Private_Subtype
- -- and it is safe to go to the Base_Type because this is the
- -- same as converting the access value to its Base_Type.
+ -- Set the Etype. We need to go thru Is_For_Access_Subtypes to
+ -- avoid other problems caused by the Private_Subtype and it is
+ -- safe to go to the Base_Type because this is the same as
+ -- converting the access value to its Base_Type.
declare
DT : Entity_Id := Designated_Type (Etype (P));
DT := Base_Type (DT);
end if;
- Set_Etype (N, DT);
+ -- An explicit dereference is a legal occurrence of an
+ -- incomplete type imported through a limited_with clause,
+ -- if the full view is visible.
+
+ if From_With_Type (DT)
+ and then not From_With_Type (Scope (DT))
+ and then
+ (Is_Immediately_Visible (Scope (DT))
+ or else
+ (Is_Child_Unit (Scope (DT))
+ and then Is_Visible_Child_Unit (Scope (DT))))
+ then
+ Set_Etype (N, Available_View (DT));
+
+ else
+ Set_Etype (N, DT);
+ end if;
end;
elsif Etype (P) /= Any_Type then
else
Get_First_Interp (P, I, It);
-
while Present (It.Nam) loop
T := It.Typ;
Set_Name (N, P);
Set_Parameter_Associations (N, Exprs);
+ -- Analyze actuals prior to analyzing the call itself
+
Actual := First (Parameter_Associations (N));
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
- Next_Actual (Actual);
+
+ -- Move to next actual. Note that we use Next, not Next_Actual
+ -- here. The reason for this is a bit subtle. If a function call
+ -- includes named associations, the parser recognizes the node as
+ -- a call, and it is analyzed as such. If all associations are
+ -- positional, the parser builds an indexed_component node, and
+ -- it is only after analysis of the prefix that the construct
+ -- is recognized as a call, in which case Process_Function_Call
+ -- rewrites the node and analyzes the actuals. If the list of
+ -- actuals is malformed, the parser may leave the node as an
+ -- indexed component (despite the presence of named associations).
+ -- The iterator Next_Actual is equivalent to Next if the list is
+ -- positional, but follows the normalized chain of actuals when
+ -- named associations are present. In this case normalization has
+ -- not taken place, and actuals remain unanalyzed, which leads to
+ -- subsequent crashes or loops if there is an attempt to continue
+ -- analysis of the program.
+
+ Next (Actual);
end loop;
Analyze_Call (N);
end if;
Index := First_Index (Array_Type);
-
while Present (Index) and then Present (Exp) loop
if not Has_Compatible_Type (Exp, Etype (Index)) then
Wrong_Type (Exp, Etype (Index));
then
U_N := Entity (P);
- if Ekind (U_N) in Type_Kind then
+ if Is_Type (U_N) then
-- Reformat node as a type conversion
else
Op_Id := Get_Name_Entity_Id (Chars (N));
-
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Boolean_Types (L, R, Op_Id, N);
else
Get_First_Interp (L, Index, It);
-
while Present (It.Typ) loop
Try_One_Interp (It.Typ);
Get_Next_Interp (Index, It);
-- in any case.
Set_Etype (N, Standard_Boolean);
+
+ if Comes_From_Source (N)
+ and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
+ then
+ Error_Msg_N ("membership test not applicable to cpp-class types", N);
+ end if;
end Analyze_Membership_Op;
----------------------
----------------------
procedure Analyze_One_Call
- (N : Node_Id;
- Nam : Entity_Id;
- Report : Boolean;
- Success : out Boolean)
+ (N : Node_Id;
+ Nam : Entity_Id;
+ Report : Boolean;
+ Success : out Boolean;
+ Skip_First : Boolean := False)
is
Actuals : constant List_Id := Parameter_Associations (N);
Prev_T : constant Entity_Id := Etype (N);
+ Must_Skip : constant Boolean := Skip_First
+ or else Nkind (Original_Node (N)) = N_Selected_Component
+ or else
+ (Nkind (Original_Node (N)) = N_Indexed_Component
+ and then Nkind (Prefix (Original_Node (N)))
+ = N_Selected_Component);
+ -- The first formal must be omitted from the match when trying to find
+ -- a primitive operation that is a possible interpretation, and also
+ -- after the call has been rewritten, because the corresponding actual
+ -- is already known to be compatible, and because this may be an
+ -- indexing of a call with default parameters.
+
Formal : Entity_Id;
Actual : Node_Id;
Is_Indexed : Boolean := False;
Subp_Type : constant Entity_Id := Etype (Nam);
Norm_OK : Boolean;
+ function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
+ -- There may be a user-defined operator that hides the current
+ -- interpretation. We must check for this independently of the
+ -- analysis of the call with the user-defined operation, because
+ -- the parameter names may be wrong and yet the hiding takes place.
+ -- This fixes a problem with ACATS test B34014O.
+ --
+ -- When the type Address is a visible integer type, and the DEC
+ -- system extension is visible, the predefined operator may be
+ -- hidden as well, by one of the address operations in auxdec.
+ -- Finally, The abstract operations on address do not hide the
+ -- predefined operator (this is the purpose of making them abstract).
+
procedure Indicate_Name_And_Type;
-- If candidate interpretation matches, indicate name and type of
-- result on call node.
end if;
end Indicate_Name_And_Type;
+ ------------------------
+ -- Operator_Hidden_By --
+ ------------------------
+
+ function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
+ Act1 : constant Node_Id := First_Actual (N);
+ Act2 : constant Node_Id := Next_Actual (Act1);
+ Form1 : constant Entity_Id := First_Formal (Fun);
+ Form2 : constant Entity_Id := Next_Formal (Form1);
+
+ begin
+ if Ekind (Fun) /= E_Function
+ or else Is_Abstract_Subprogram (Fun)
+ then
+ return False;
+
+ elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
+ return False;
+
+ elsif Present (Form2) then
+ if
+ No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2))
+ then
+ return False;
+ end if;
+
+ elsif Present (Act2) then
+ return False;
+ end if;
+
+ -- Now we know that the arity of the operator matches the function,
+ -- and the function call is a valid interpretation. The function
+ -- hides the operator if it has the right signature, or if one of
+ -- its operands is a non-abstract operation on Address when this is
+ -- a visible integer type.
+
+ return Hides_Op (Fun, Nam)
+ or else Is_Descendent_Of_Address (Etype (Form1))
+ or else
+ (Present (Form2)
+ and then Is_Descendent_Of_Address (Etype (Form2)));
+ end Operator_Hidden_By;
+
-- Start of processing for Analyze_One_Call
begin
Success := False;
- -- If the subprogram has no formals, or if all the formals have
- -- defaults, and the return type is an array type, the node may
- -- denote an indexing of the result of a parameterless call.
+ -- If the subprogram has no formals or if all the formals have defaults,
+ -- and the return type is an array type, the node may denote an indexing
+ -- of the result of a parameterless call. In Ada 2005, the subprogram
+ -- may have one non-defaulted formal, and the call may have been written
+ -- in prefix notation, so that the rebuilt parameter list has more than
+ -- one actual.
- if Needs_No_Actuals (Nam)
- and then Present (Actuals)
+ if Present (Actuals)
+ and then
+ (Needs_No_Actuals (Nam)
+ or else
+ (Needs_One_Actual (Nam)
+ and then Present (Next_Actual (First (Actuals)))))
then
if Is_Array_Type (Subp_Type) then
- Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type);
+ Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
elsif Is_Access_Type (Subp_Type)
and then Is_Array_Type (Designated_Type (Subp_Type))
then
Is_Indexed :=
- Try_Indexed_Call (N, Nam, Designated_Type (Subp_Type));
+ Try_Indexed_Call
+ (N, Nam, Designated_Type (Subp_Type), Must_Skip);
-- The prefix can also be a parameterless function that returns an
-- access to subprogram. in which case this is an indirect call.
elsif Is_Access_Type (Subp_Type)
- and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
+ and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
then
Is_Indexed := Try_Indirect_Call (N, Nam, Subp_Type);
end if;
then
return;
- elsif not Present (Actuals) then
+ elsif No (Actuals) then
-- If Normalize succeeds, then there are default parameters for
-- all formals.
if Etype (N) /= Prev_T then
- -- There may be a user-defined operator that hides the
- -- current interpretation. We must check for this independently
- -- of the analysis of the call with the user-defined operation,
- -- because the parameter names may be wrong and yet the hiding
- -- takes place. Fixes b34014o.
+ -- Check that operator is not hidden by a function interpretation
if Is_Overloaded (Name (N)) then
declare
begin
Get_First_Interp (Name (N), I, It);
while Present (It.Nam) loop
- if Ekind (It.Nam) /= E_Operator
- and then Hides_Op (It.Nam, Nam)
- and then
- Has_Compatible_Type
- (First_Actual (N), Etype (First_Formal (It.Nam)))
- and then (No (Next_Actual (First_Actual (N)))
- or else Has_Compatible_Type
- (Next_Actual (First_Actual (N)),
- Etype (Next_Formal (First_Formal (It.Nam)))))
- then
+ if Operator_Hidden_By (It.Nam) then
Set_Etype (N, Prev_T);
return;
end if;
Actual := First_Actual (N);
Formal := First_Formal (Nam);
+
+ -- If we are analyzing a call rewritten from object notation,
+ -- skip first actual, which may be rewritten later as an
+ -- explicit dereference.
+
+ if Must_Skip then
+ Next_Actual (Actual);
+ Next_Formal (Formal);
+ end if;
+
while Present (Actual) and then Present (Formal) loop
if Nkind (Parent (Actual)) /= N_Parameter_Association
or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
then
- if Has_Compatible_Type (Actual, Etype (Formal)) then
+ -- The actual can be compatible with the formal, but we must
+ -- also check that the context is not an address type that is
+ -- visibly an integer type, as is the case in VMS_64. In this
+ -- case the use of literals is illegal, except in the body of
+ -- descendents of system, where arithmetic operations on
+ -- address are of course used.
+
+ if Has_Compatible_Type (Actual, Etype (Formal))
+ and then
+ (Etype (Actual) /= Universal_Integer
+ or else not Is_Descendent_Of_Address (Etype (Formal))
+ or else
+ Is_Predefined_File_Name
+ (Unit_File_Name (Get_Source_Unit (N))))
+ then
Next_Actual (Actual);
Next_Formal (Formal);
(Typ => Etype (Actual),
Iface => Etype (Etype (Formal)))
then
- Error_Msg_Name_1 := Chars (Actual);
- Error_Msg_Name_2 := Chars (Etype (Etype (Formal)));
Error_Msg_NE
- ("(Ada 2005) % does not implement interface %",
+ ("(Ada 2005) does not implement interface }",
Actual, Etype (Etype (Formal)));
end if;
and then Nkind (Left_Opnd (Actual)) = N_Identifier
then
Formal := First_Formal (Nam);
-
while Present (Formal) loop
-
if Chars (Left_Opnd (Actual)) = Chars (Formal) then
Error_Msg_N
("possible misspelling of `='>`!", Actual);
and then not Comes_From_Source (Nam)
then
Error_Msg_NE
- (" =='> in call to &#(inherited)!", Actual, Nam);
+ ("\\ =='> in call to inherited operation & #!",
+ Actual, Nam);
elsif Ekind (Nam) = E_Subprogram_Type then
declare
(Associated_Node_For_Itype (Nam));
begin
Error_Msg_NE (
- " =='> in call to dereference of &#!",
+ "\\ =='> in call to dereference of &#!",
Actual, Access_To_Subprogram_Typ);
end;
else
- Error_Msg_NE (" =='> in call to &#!", Actual, Nam);
+ Error_Msg_NE
+ ("\\ =='> in call to &#!", Actual, Nam);
end if;
end if;
if Chars (Comp) = Chars (Sel)
and then Is_Visible_Component (Comp)
then
- Set_Entity_With_Style_Check (Sel, Comp);
- Generate_Reference (Comp, Sel);
-
+ Set_Entity (Sel, Comp);
Set_Etype (Sel, Etype (Comp));
Add_One_Interp (N, Etype (Comp), Etype (Comp));
Get_Next_Interp (I, It);
end loop;
- if Etype (N) = Any_Type then
+ if Etype (N) = Any_Type
+ and then not Try_Object_Operation (N)
+ then
Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel);
Set_Entity (Sel, Any_Id);
Set_Etype (Sel, Any_Type);
procedure Analyze_Qualified_Expression (N : Node_Id) is
Mark : constant Entity_Id := Subtype_Mark (N);
+ Expr : constant Node_Id := Expression (N);
+ I : Interp_Index;
+ It : Interp;
T : Entity_Id;
begin
+ Analyze_Expression (Expr);
+
Set_Etype (N, Any_Type);
Find_Type (Mark);
T := Entity (Mark);
+ Set_Etype (N, T);
if T = Any_Type then
return;
end if;
Check_Fully_Declared (T, N);
- Analyze_Expression (Expression (N));
+
+ -- If expected type is class-wide, check for exact match before
+ -- expansion, because if the expression is a dispatching call it
+ -- may be rewritten as explicit dereference with class-wide result.
+ -- If expression is overloaded, retain only interpretations that
+ -- will yield exact matches.
+
+ if Is_Class_Wide_Type (T) then
+ if not Is_Overloaded (Expr) then
+ if Base_Type (Etype (Expr)) /= Base_Type (T) then
+ if Nkind (Expr) = N_Aggregate then
+ Error_Msg_N ("type of aggregate cannot be class-wide", Expr);
+ else
+ Wrong_Type (Expr, T);
+ end if;
+ end if;
+
+ else
+ Get_First_Interp (Expr, I, It);
+
+ while Present (It.Nam) loop
+ if Base_Type (It.Typ) /= Base_Type (T) then
+ Remove_Interp (I);
+ end if;
+
+ Get_Next_Interp (I, It);
+ end loop;
+ end if;
+ end if;
+
Set_Etype (N, T);
end Analyze_Qualified_Expression;
Name : constant Node_Id := Prefix (N);
Sel : constant Node_Id := Selector_Name (N);
Comp : Entity_Id;
- Entity_List : Entity_Id;
Prefix_Type : Entity_Id;
+
+ Type_To_Use : Entity_Id;
+ -- In most cases this is the Prefix_Type, but if the Prefix_Type is
+ -- a class-wide type, we use its root type, whose components are
+ -- present in the class-wide type.
+
Pent : Entity_Id := Empty;
Act_Decl : Node_Id;
In_Scope : Boolean;
return;
else
- -- Function calls that are prefixes of selected components must be
- -- fully resolved in case we need to build an actual subtype, or
- -- do some other operation requiring a fully resolved prefix.
-
- -- Note: Resolving all Nkinds of nodes here doesn't work.
- -- (Breaks 2129-008) ???.
-
- if Nkind (Name) = N_Function_Call then
- Resolve (Name);
- end if;
-
Prefix_Type := Etype (Name);
end if;
end if;
Prefix_Type := Designated_Type (Prefix_Type);
+
+ end if;
+
+ -- (Ada 2005): if the prefix is the limited view of a type, and
+ -- the context already includes the full view, use the full view
+ -- in what follows, either to retrieve a component of to find
+ -- a primitive operation. If the prefix is an explicit dereference,
+ -- set the type of the prefix to reflect this transformation.
+ -- If the non-limited view is itself an incomplete type, get the
+ -- full view if available.
+
+ if Is_Incomplete_Type (Prefix_Type)
+ and then From_With_Type (Prefix_Type)
+ and then Present (Non_Limited_View (Prefix_Type))
+ then
+ Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type));
+
+ if Nkind (N) = N_Explicit_Dereference then
+ Set_Etype (Prefix (N), Prefix_Type);
+ end if;
+
+ elsif Ekind (Prefix_Type) = E_Class_Wide_Type
+ and then From_With_Type (Prefix_Type)
+ and then Present (Non_Limited_View (Etype (Prefix_Type)))
+ then
+ Prefix_Type :=
+ Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type)));
+
+ if Nkind (N) = N_Explicit_Dereference then
+ Set_Etype (Prefix (N), Prefix_Type);
+ end if;
end if;
if Ekind (Prefix_Type) = E_Private_Subtype then
Prefix_Type := Base_Type (Prefix_Type);
end if;
- Entity_List := Prefix_Type;
+ Type_To_Use := Prefix_Type;
-- For class-wide types, use the entity list of the root type. This
-- indirection is specially important for private extensions because
-- only the root type get switched (not the class-wide type).
if Is_Class_Wide_Type (Prefix_Type) then
- Entity_List := Root_Type (Prefix_Type);
+ Type_To_Use := Root_Type (Prefix_Type);
end if;
- Comp := First_Entity (Entity_List);
+ Comp := First_Entity (Type_To_Use);
-- If the selector has an original discriminant, the node appears in
-- an instance. Replace the discriminant with the corresponding one
and then Is_Visible_Component (Comp)
then
Set_Entity_With_Style_Check (Sel, Comp);
- Generate_Reference (Comp, Sel);
-
Set_Etype (Sel, Etype (Comp));
if Ekind (Comp) = E_Discriminant then
Resolve (Name);
- -- Ada 2005 (AI-50217): Check wrong use of incomplete type.
+ -- Ada 2005 (AI-50217): Check wrong use of incomplete types or
+ -- subtypes in a package specification.
-- Example:
-- limited with Pkg;
-- package Pkg is
-- type Acc_Inc is access Pkg.T;
-- X : Acc_Inc;
- -- N : Natural := X.all.Comp; -- ERROR
- -- end Pkg;
+ -- N : Natural := X.all.Comp; -- ERROR, limited view
+ -- end Pkg; -- Comp is not visible
if Nkind (Name) = N_Explicit_Dereference
and then From_With_Type (Etype (Prefix (Name)))
and then not Is_Potentially_Use_Visible (Etype (Name))
+ and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) =
+ N_Package_Specification
then
Error_Msg_NE
("premature usage of incomplete}", Prefix (Name),
return;
end if;
+ -- If the prefix is a private extension, check only the visible
+ -- components of the partial view. This must include the tag,
+ -- wich can appear in expanded code in a tag check.
+
+ if Ekind (Type_To_Use) = E_Record_Type_With_Private
+ and then Chars (Selector_Name (N)) /= Name_uTag
+ then
+ exit when Comp = Last_Entity (Type_To_Use);
+ end if;
+
Next_Entity (Comp);
end loop;
end if;
elsif Is_Private_Type (Prefix_Type) then
-
-- Allow access only to discriminants of the type. If the type has
-- no full view, gigi uses the parent type for the components, so we
-- do the same here.
if No (Full_View (Prefix_Type)) then
- Entity_List := Root_Type (Base_Type (Prefix_Type));
- Comp := First_Entity (Entity_List);
+ Type_To_Use := Root_Type (Base_Type (Prefix_Type));
+ Comp := First_Entity (Type_To_Use);
end if;
while Present (Comp) loop
Set_Original_Discriminant (Sel, Comp);
end if;
+ -- Before declararing an error, check whether this is tagged
+ -- private type and a call to a primitive operation.
+
+ elsif Ada_Version >= Ada_05
+ and then Is_Tagged_Type (Prefix_Type)
+ and then Try_Object_Operation (N)
+ then
+ return;
+
else
Error_Msg_NE
("invisible selector for }",
Comp = First_Private_Entity (Base_Type (Prefix_Type));
end loop;
+ -- If there is no visible entry with the given name, and the task
+ -- implements an interface, check whether there is some other
+ -- primitive operation with that name.
+
+ if Ada_Version >= Ada_05
+ and then Is_Tagged_Type (Prefix_Type)
+ then
+ if Etype (N) = Any_Type
+ and then Try_Object_Operation (N)
+ then
+ return;
+
+ -- If the context is not syntactically a procedure call, it
+ -- may be a call to a primitive function declared outside of
+ -- the synchronized type.
+
+ -- If the context is a procedure call, there might still be
+ -- an overloading between an entry and a primitive procedure
+ -- declared outside of the synchronized type, called in prefix
+ -- notation. This is harder to disambiguate because in one case
+ -- the controlling formal is implicit ???
+
+ elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement
+ and then Try_Object_Operation (N)
+ then
+ return;
+ end if;
+ end if;
+
Set_Is_Overloaded (N, Is_Overloaded (Sel));
else
Error_Msg_Node_2 := Entity (Name);
Error_Msg_NE ("no selector& for&", N, Sel);
- Check_Misspelled_Selector (Entity_List, Sel);
+ Check_Misspelled_Selector (Type_To_Use, Sel);
elsif Is_Generic_Type (Prefix_Type)
and then Ekind (Prefix_Type) = E_Record_Type_With_Private
Set_Entity_With_Style_Check (Sel, Comp);
Set_Etype (Sel, Etype (Comp));
Set_Etype (N, Etype (Comp));
- exit;
+ return;
end if;
Next_Component (Comp);
Error_Msg_Node_2 := First_Subtype (Prefix_Type);
Error_Msg_NE ("no selector& for}", N, Sel);
- Check_Misspelled_Selector (Entity_List, Sel);
+ Check_Misspelled_Selector (Type_To_Use, Sel);
end if;
else
Get_First_Interp (L, Ind, It);
-
while Present (It.Typ) loop
if Root_Type (It.Typ) = Standard_Boolean
and then Has_Compatible_Type (R, It.Typ)
if not Comes_From_Source (N) then
return;
+ -- If there was an error in a generic unit, no need to replicate the
+ -- error message. Conversely, constant-folding in the generic may
+ -- transform the argument of a conversion into a string literal, which
+ -- is legal. Therefore the following tests are not performed in an
+ -- instance.
+
+ elsif In_Instance then
+ return;
+
elsif Nkind (Expr) = N_Null then
Error_Msg_N ("argument of conversion cannot be null", N);
Error_Msg_N ("\use qualified expression instead", N);
Op_Id : Entity_Id;
N : Node_Id)
is
- Op_Name : constant Name_Id := Chars (Op_Id);
+ Op_Name : constant Name_Id := Chars (Op_Id);
function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean;
-- Check whether the fixed-point type Typ has a user-defined operator
------------------
function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is
+ Bas : constant Entity_Id := Base_Type (Typ);
Ent : Entity_Id;
F1 : Entity_Id;
F2 : Entity_Id;
F2 := Next_Formal (F1);
-- The operation counts as primitive if either operand or
- -- result are of the given type, and both operands are fixed
- -- point types.
+ -- result are of the given base type, and both operands are
+ -- fixed point types.
- if (Etype (F1) = Typ
+ if (Base_Type (Etype (F1)) = Bas
and then Is_Fixed_Point_Type (Etype (F2)))
or else
- (Etype (F2) = Typ
+ (Base_Type (Etype (F2)) = Bas
and then Is_Fixed_Point_Type (Etype (F1)))
or else
- (Etype (Ent) = Typ
+ (Base_Type (Etype (Ent)) = Bas
and then Is_Fixed_Point_Type (Etype (F1))
and then Is_Fixed_Point_Type (Etype (F2)))
then
if (Nkind (N) not in N_Op
or else not Treat_Fixed_As_Integer (N))
and then
- (not (Ada_Version >= Ada_05 and then Has_Fixed_Op (T1, Op_Id))
+ (not Has_Fixed_Op (T1, Op_Id)
or else Nkind (Parent (N)) = N_Type_Conversion)
then
Add_One_Interp (N, Op_Id, Universal_Fixed);
or else not Treat_Fixed_As_Integer (N))
and then T1 = Universal_Real
and then
- (not (Ada_Version >= Ada_05 and then Has_Fixed_Op (T1, Op_Id))
+ (not Has_Fixed_Op (T1, Op_Id)
or else Nkind (Parent (N)) = N_Type_Conversion)
then
Add_One_Interp (N, Op_Id, Universal_Fixed);
else
Get_First_Interp (L, Index1, It1);
-
while Present (It1.Typ) loop
Check_Right_Argument (It1.Typ);
Get_Next_Interp (Index1, It1);
end loop;
end if;
+ -- If operands are aggregates, we must assume that they may be
+ -- boolean arrays, and leave disambiguation for the second pass.
+ -- If only one is an aggregate, verify that the other one has an
+ -- interpretation as a boolean array
+
+ elsif Nkind (L) = N_Aggregate then
+ if Nkind (R) = N_Aggregate then
+ Add_One_Interp (N, Op_Id, Etype (L));
+
+ elsif not Is_Overloaded (R) then
+ if Valid_Boolean_Arg (Etype (R)) then
+ Add_One_Interp (N, Op_Id, Etype (R));
+ end if;
+
+ else
+ Get_First_Interp (R, Index, It);
+ while Present (It.Typ) loop
+ if Valid_Boolean_Arg (It.Typ) then
+ Add_One_Interp (N, Op_Id, It.Typ);
+ end if;
+
+ Get_Next_Interp (Index, It);
+ end loop;
+ end if;
+
elsif Valid_Boolean_Arg (Etype (L))
and then Has_Compatible_Type (R, Etype (L))
then
-- universal, the context will impose the correct type. An anonymous
-- type for a 'Access reference is also universal in this sense, as
-- the actual type is obtained from context.
+ -- In Ada 2005, the equality operator for anonymous access types
+ -- is declared in Standard, and preference rules apply to it.
- if Present (Scop)
- and then not Defined_In_Scope (T1, Scop)
- and then T1 /= Universal_Integer
- and then T1 /= Universal_Real
- and then T1 /= Any_Access
- and then T1 /= Any_String
- and then T1 /= Any_Composite
- and then (Ekind (T1) /= E_Access_Subprogram_Type
- or else Comes_From_Source (T1))
- then
- return;
+ if Present (Scop) then
+ if Defined_In_Scope (T1, Scop)
+ or else T1 = Universal_Integer
+ or else T1 = Universal_Real
+ or else T1 = Any_Access
+ or else T1 = Any_String
+ or else T1 = Any_Composite
+ or else (Ekind (T1) = E_Access_Subprogram_Type
+ and then not Comes_From_Source (T1))
+ then
+ null;
+
+ elsif Ekind (T1) = E_Anonymous_Access_Type
+ and then Scop = Standard_Standard
+ then
+ null;
+
+ else
+ -- The scope does not contain an operator for the type
+
+ return;
+ end if;
end if;
-- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95:
if Etype (N) = Any_Type then
Found := False;
end if;
+
+ elsif Scop = Standard_Standard
+ and then Ekind (T1) = E_Anonymous_Access_Type
+ then
+ Found := True;
end if;
end Try_One_Interp;
return False;
end if;
- -- Now test the entity we got to see if it a bad case
+ -- Now test the entity we got to see if it is a bad case
case Ekind (Entity (Enode)) is
if Etype (N) = Any_Type then
declare
- L : Node_Id;
- R : Node_Id;
+ L : Node_Id;
+ R : Node_Id;
+ Op_Id : Entity_Id := Empty;
begin
R := Right_Opnd (N);
end if;
-- If either operand has no type, then don't complain further,
- -- since this simply means that we have a propragated error.
+ -- since this simply means that we have a propagated error.
if R = Error
or else Etype (R) = Any_Type
-- If either operand is a junk operand (e.g. package name), then
-- post appropriate error messages, but do not complain further.
- -- Note that the use of OR in this test instead of OR ELSE
- -- is quite deliberate, we may as well check both operands
- -- in the binary operator case.
+ -- Note that the use of OR in this test instead of OR ELSE is
+ -- quite deliberate, we may as well check both operands in the
+ -- binary operator case.
elsif Junk_Operand (R)
or (Nkind (N) in N_Binary_Op and then Junk_Operand (L))
return;
-- If we have a logical operator, one of whose operands is
- -- Boolean, then we know that the other operand cannot resolve
- -- to Boolean (since we got no interpretations), but in that
- -- case we pretty much know that the other operand should be
- -- Boolean, so resolve it that way (generating an error)
+ -- Boolean, then we know that the other operand cannot resolve to
+ -- Boolean (since we got no interpretations), but in that case we
+ -- pretty much know that the other operand should be Boolean, so
+ -- resolve it that way (generating an error)
elsif Nkind (N) = N_Op_And
or else
Error_Msg_N
("two access attributes cannot be compared directly", N);
Error_Msg_N
- ("\they must be converted to an explicit type for comparison",
+ ("\use qualified expression for one of the operands",
N);
return;
return;
end if;
- -- If we fall through then just give general message. Note
- -- that in the following messages, if the operand is overloaded
- -- we choose an arbitrary type to complain about, but that is
- -- probably more useful than not giving a type at all.
+ -- If we fall through then just give general message. Note that in
+ -- the following messages, if the operand is overloaded we choose
+ -- an arbitrary type to complain about, but that is probably more
+ -- useful than not giving a type at all.
if Nkind (N) in N_Unary_Op then
Error_Msg_Node_2 := Etype (R);
Error_Msg_N ("there is no applicable operator& for}", N);
else
- Error_Msg_N ("invalid operand types for operator&", N);
+ -- Another attempt to find a fix: one of the candidate
+ -- interpretations may not be use-visible. This has
+ -- already been checked for predefined operators, so
+ -- we examine only user-defined functions.
- if Nkind (N) /= N_Op_Concat then
- Error_Msg_NE ("\left operand has}!", N, Etype (L));
- Error_Msg_NE ("\right operand has}!", N, Etype (R));
+ Op_Id := Get_Name_Entity_Id (Chars (N));
+
+ while Present (Op_Id) loop
+ if Ekind (Op_Id) /= E_Operator
+ and then Is_Overloadable (Op_Id)
+ then
+ if not Is_Immediately_Visible (Op_Id)
+ and then not In_Use (Scope (Op_Id))
+ and then not Is_Abstract_Subprogram (Op_Id)
+ and then not Is_Hidden (Op_Id)
+ and then Ekind (Scope (Op_Id)) = E_Package
+ and then
+ Has_Compatible_Type
+ (L, Etype (First_Formal (Op_Id)))
+ and then Present
+ (Next_Formal (First_Formal (Op_Id)))
+ and then
+ Has_Compatible_Type
+ (R,
+ Etype (Next_Formal (First_Formal (Op_Id))))
+ then
+ Error_Msg_N
+ ("No legal interpretation for operator&", N);
+ Error_Msg_NE
+ ("\use clause on& would make operation legal",
+ N, Scope (Op_Id));
+ exit;
+ end if;
+ end if;
+
+ Op_Id := Homonym (Op_Id);
+ end loop;
+
+ if No (Op_Id) then
+ Error_Msg_N ("invalid operand types for operator&", N);
+
+ if Nkind (N) /= N_Op_Concat then
+ Error_Msg_NE ("\left operand has}!", N, Etype (L));
+ Error_Msg_NE ("\right operand has}!", N, Etype (R));
+ end if;
end if;
end if;
end if;
--------------------------------
procedure Remove_Abstract_Operations (N : Node_Id) is
- I : Interp_Index;
- It : Interp;
- Abstract_Op : Entity_Id := Empty;
-
- -- AI-310: If overloaded, remove abstract non-dispatching
- -- operations. We activate this if either extensions are
- -- enabled, or if the abstract operation in question comes
- -- from a predefined file. This latter test allows us to
- -- use abstract to make operations invisible to users. In
- -- particular, if type Address is non-private and abstract
- -- subprograms are used to hide its operators, they will be
- -- truly hidden.
+ Abstract_Op : Entity_Id := Empty;
+ Address_Kludge : Boolean := False;
+ I : Interp_Index;
+ It : Interp;
+
+ -- AI-310: If overloaded, remove abstract non-dispatching operations. We
+ -- activate this if either extensions are enabled, or if the abstract
+ -- operation in question comes from a predefined file. This latter test
+ -- allows us to use abstract to make operations invisible to users. In
+ -- particular, if type Address is non-private and abstract subprograms
+ -- are used to hide its operators, they will be truly hidden.
type Operand_Position is (First_Op, Second_Op);
Univ_Type : constant Entity_Id := Universal_Interpretation (N);
procedure Remove_Address_Interpretations (Op : Operand_Position);
- -- Ambiguities may arise when the operands are literal and the
- -- address operations in s-auxdec are visible. In that case, remove
- -- the interpretation of a literal as Address, to retain the semantics
- -- of Address as a private type.
+ -- Ambiguities may arise when the operands are literal and the address
+ -- operations in s-auxdec are visible. In that case, remove the
+ -- interpretation of a literal as Address, to retain the semantics of
+ -- Address as a private type.
------------------------------------
-- Remove_Address_Interpretations --
end if;
if Is_Descendent_Of_Address (Etype (Formal)) then
+ Address_Kludge := True;
Remove_Interp (I);
end if;
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
- if not Is_Type (It.Nam)
- and then Is_Abstract (It.Nam)
+ if Is_Overloadable (It.Nam)
+ and then Is_Abstract_Subprogram (It.Nam)
and then not Is_Dispatching_Operation (It.Nam)
- and then
- (Ada_Version >= Ada_05
- or else Is_Predefined_File_Name
- (Unit_File_Name (Get_Source_Unit (It.Nam))))
-
then
Abstract_Op := It.Nam;
- Remove_Interp (I);
- exit;
+
+ if Is_Descendent_Of_Address (It.Typ) then
+ Address_Kludge := True;
+ Remove_Interp (I);
+ exit;
+
+ -- In Ada 2005, this operation does not participate in Overload
+ -- resolution. If the operation is defined in a predefined
+ -- unit, it is one of the operations declared abstract in some
+ -- variants of System, and it must be removed as well.
+
+ elsif Ada_Version >= Ada_05
+ or else Is_Predefined_File_Name
+ (Unit_File_Name (Get_Source_Unit (It.Nam)))
+ then
+ Remove_Interp (I);
+ exit;
+ end if;
end if;
Get_Next_Interp (I, It);
end loop;
if No (Abstract_Op) then
- return;
+
+ -- If some interpretation yields an integer type, it is still
+ -- possible that there are address interpretations. Remove them
+ -- if one operand is a literal, to avoid spurious ambiguities
+ -- on systems where Address is a visible integer type.
+
+ if Is_Overloaded (N)
+ and then Nkind (N) in N_Op
+ and then Is_Integer_Type (Etype (N))
+ then
+ if Nkind (N) in N_Binary_Op then
+ if Nkind (Right_Opnd (N)) = N_Integer_Literal then
+ Remove_Address_Interpretations (Second_Op);
+
+ elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then
+ Remove_Address_Interpretations (First_Op);
+ end if;
+ end if;
+ end if;
elsif Nkind (N) in N_Op then
- -- Remove interpretations that treat literals as addresses.
- -- This is never appropriate.
+ -- Remove interpretations that treat literals as addresses. This
+ -- is never appropriate, even when Address is defined as a visible
+ -- Integer type. The reason is that we would really prefer Address
+ -- to behave as a private type, even in this case, which is there
+ -- only to accomodate oddities of VMS address sizes. If Address is
+ -- a visible integer type, we get lots of overload ambiguities.
if Nkind (N) in N_Binary_Op then
declare
Present (Universal_Interpretation (Left_Opnd (N)));
begin
- if U1 and then not U2 then
+ if U1 then
Remove_Address_Interpretations (Second_Op);
+ end if;
- elsif U2 and then not U1 then
+ if U2 then
Remove_Address_Interpretations (First_Op);
end if;
and then Present (Univ_Type)
then
-- If both operands have a universal interpretation,
- -- select the predefined operator and discard others.
+ -- it is still necessary to remove interpretations that
+ -- yield Address. Any remaining ambiguities will be
+ -- removed in Disambiguate.
Get_First_Interp (N, I, It);
-
while Present (It.Nam) loop
- if Scope (It.Nam) = Standard_Standard then
- Set_Etype (N, Univ_Type);
+ if Is_Descendent_Of_Address (It.Typ) then
+ Remove_Interp (I);
+
+ elsif not Is_Type (It.Nam) then
Set_Entity (N, It.Nam);
- Set_Is_Overloaded (N, False);
- exit;
end if;
Get_Next_Interp (I, It);
Present (Universal_Interpretation (Next (Arg1)));
begin
- if U1 and then not U2 then
+ if U1 then
Remove_Address_Interpretations (First_Op);
+ end if;
- elsif U2 and then not U1 then
+ if U2 then
Remove_Address_Interpretations (Second_Op);
end if;
end;
end if;
- -- If the removal has left no valid interpretations, emit
- -- error message now and label node as illegal.
+ -- If the removal has left no valid interpretations, emit an error
+ -- message now and label node as illegal.
if Present (Abstract_Op) then
Get_First_Interp (N, I, It);
Error_Msg_Sloc := Sloc (Abstract_Op);
Error_Msg_NE
("cannot call abstract operation& declared#", N, Abstract_Op);
+
+ -- In Ada 2005, an abstract operation may disable predefined
+ -- operators. Since the context is not yet known, we mark the
+ -- predefined operators as potentially hidden. Do not include
+ -- predefined operators when addresses are involved since this
+ -- case is handled separately.
+
+ elsif Ada_Version >= Ada_05
+ and then not Address_Kludge
+ then
+ while Present (It.Nam) loop
+ if Is_Numeric_Type (It.Typ)
+ and then Scope (It.Typ) = Standard_Standard
+ then
+ Set_Abstract_Op (I, Abstract_Op);
+ end if;
+
+ Get_Next_Interp (I, It);
+ end loop;
end if;
end if;
end if;
begin
Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK);
+
Actual := First_Actual (N);
Formal := First_Formal (Designated_Type (Typ));
-
- while Present (Actual)
- and then Present (Formal)
- loop
+ while Present (Actual) and then Present (Formal) loop
if not Has_Compatible_Type (Actual, Etype (Formal)) then
return False;
end if;
----------------------
function Try_Indexed_Call
- (N : Node_Id;
- Nam : Entity_Id;
- Typ : Entity_Id) return Boolean
+ (N : Node_Id;
+ Nam : Entity_Id;
+ Typ : Entity_Id;
+ Skip_First : Boolean) return Boolean
is
Actuals : constant List_Id := Parameter_Associations (N);
Actual : Node_Id;
begin
Actual := First (Actuals);
+
+ -- If the call was originally written in prefix form, skip the first
+ -- actual, which is obviously not defaulted.
+
+ if Skip_First then
+ Next (Actual);
+ end if;
+
Index := First_Index (Typ);
- while Present (Actual)
- and then Present (Index)
- loop
+ while Present (Actual) and then Present (Index) loop
+
-- If the parameter list has a named association, the expression
-- is definitely a call and not an indexed component.
--------------------------
function Try_Object_Operation (N : Node_Id) return Boolean is
- K : constant Node_Kind := Nkind (Parent (N));
- Loc : constant Source_Ptr := Sloc (N);
- Is_Subprg_Call : constant Boolean := K = N_Procedure_Call_Statement
- or else K = N_Function_Call;
- Obj : constant Node_Id := Prefix (N);
- Subprog : constant Node_Id := Selector_Name (N);
+ K : constant Node_Kind := Nkind (Parent (N));
+ Loc : constant Source_Ptr := Sloc (N);
+ Candidate : Entity_Id := Empty;
+ Is_Subprg_Call : constant Boolean := K = N_Procedure_Call_Statement
+ or else K = N_Function_Call;
+ Obj : constant Node_Id := Prefix (N);
+ Subprog : constant Node_Id :=
+ Make_Identifier (Sloc (Selector_Name (N)),
+ Chars => Chars (Selector_Name (N)));
+ -- Identifier on which possible interpretations will be collected
+
+ Success : Boolean := False;
+
+ Report_Error : Boolean := False;
+ -- If no candidate interpretation matches the context, redo the
+ -- analysis with error enabled to provide additional information.
Actual : Node_Id;
- Call_Node : Node_Id;
- Call_Node_Case : Node_Id := Empty;
- First_Actual : Node_Id;
+ New_Call_Node : Node_Id := Empty;
Node_To_Replace : Node_Id;
Obj_Type : Entity_Id := Etype (Obj);
+ function Valid_Candidate
+ (Success : Boolean;
+ Call : Node_Id;
+ Subp : Entity_Id) return Entity_Id;
+ -- If the subprogram is a valid interpretation, record it, and add
+ -- to the list of interpretations of Subprog.
+
procedure Complete_Object_Operation
(Call_Node : Node_Id;
- Node_To_Replace : Node_Id;
- Subprog : Node_Id);
- -- Set Subprog as the name of Call_Node, replace Node_To_Replace with
- -- Call_Node and reanalyze Node_To_Replace.
+ Node_To_Replace : Node_Id);
+ -- Make Subprog the name of Call_Node, replace Node_To_Replace with
+ -- Call_Node, insert the object (or its dereference) as the first actual
+ -- in the call, and complete the analysis of the call.
+
+ procedure Report_Ambiguity (Op : Entity_Id);
+ -- If a prefixed procedure call is ambiguous, indicate whether the
+ -- call includes an implicit dereference or an implicit 'Access.
procedure Transform_Object_Operation
(Call_Node : out Node_Id;
- First_Actual : Node_Id;
- Node_To_Replace : out Node_Id;
- Subprog : Node_Id);
- -- Transform Object.Operation (...) to Operation (Object, ...)
- -- Call_Node is the resulting subprogram call node, First_Actual is
- -- either the object Obj or an explicit dereference of Obj in certain
- -- cases, Node_To_Replace is either N or the parent of N, and Subprog
- -- is the subprogram we are trying to match.
+ Node_To_Replace : out Node_Id);
+ -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..)
+ -- Call_Node is the resulting subprogram call,
+ -- Node_To_Replace is either N or the parent of N, and Subprog
+ -- is a reference to the subprogram we are trying to match.
function Try_Class_Wide_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean;
- -- Traverse all the ancestor types looking for a class-wide subprogram
- -- that matches Subprog.
+ -- Traverse all ancestor types looking for a class-wide subprogram
+ -- for which the current operation is a valid non-dispatching call.
+
+ procedure Try_One_Prefix_Interpretation (T : Entity_Id);
+ -- If prefix is overloaded, its interpretation may include different
+ -- tagged types, and we must examine the primitive operations and
+ -- the class-wide operations of each in order to find candidate
+ -- interpretations for the call as a whole.
function Try_Primitive_Operation
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean;
- -- Traverse the list of primitive subprograms looking for a subprogram
- -- than matches Subprog.
+ -- Traverse the list of primitive subprograms looking for a dispatching
+ -- operation for which the current node is a valid call .
+
+ ---------------------
+ -- Valid_Candidate --
+ ---------------------
+
+ function Valid_Candidate
+ (Success : Boolean;
+ Call : Node_Id;
+ Subp : Entity_Id) return Entity_Id
+ is
+ Comp_Type : Entity_Id;
+
+ begin
+ -- If the subprogram is a valid interpretation, record it in global
+ -- variable Subprog, to collect all possible overloadings.
+
+ if Success then
+ if Subp /= Entity (Subprog) then
+ Add_One_Interp (Subprog, Subp, Etype (Subp));
+ end if;
+ end if;
+
+ -- If the call may be an indexed call, retrieve component type
+ -- of resulting expression, and add possible interpretation.
+
+ Comp_Type := Empty;
+
+ if Nkind (Call) = N_Function_Call
+ and then Nkind (Parent (N)) = N_Indexed_Component
+ and then Needs_One_Actual (Subp)
+ then
+ if Is_Array_Type (Etype (Subp)) then
+ Comp_Type := Component_Type (Etype (Subp));
+
+ elsif Is_Access_Type (Etype (Subp))
+ and then Is_Array_Type (Designated_Type (Etype (Subp)))
+ then
+ Comp_Type := Component_Type (Designated_Type (Etype (Subp)));
+ end if;
+ end if;
+
+ if Present (Comp_Type)
+ and then Etype (Subprog) /= Comp_Type
+ then
+ Add_One_Interp (Subprog, Subp, Comp_Type);
+ end if;
+
+ if Etype (Call) /= Any_Type then
+ return Subp;
+ else
+ return Empty;
+ end if;
+ end Valid_Candidate;
-------------------------------
-- Complete_Object_Operation --
procedure Complete_Object_Operation
(Call_Node : Node_Id;
- Node_To_Replace : Node_Id;
- Subprog : Node_Id)
+ Node_To_Replace : Node_Id)
is
+ Formal_Type : constant Entity_Id :=
+ Etype (First_Formal (Entity (Subprog)));
+ First_Actual : Node_Id;
+
begin
- Set_Name (Call_Node, New_Copy_Tree (Subprog));
- Set_Analyzed (Call_Node, False);
+ -- Place the name of the operation, with its interpretations,
+ -- on the rewritten call.
+
+ Set_Name (Call_Node, Subprog);
+
+ First_Actual := First (Parameter_Associations (Call_Node));
+
+ -- For cross-reference purposes, treat the new node as being in
+ -- the source if the original one is.
+
+ Set_Comes_From_Source (Subprog, Comes_From_Source (N));
+ Set_Comes_From_Source (Call_Node, Comes_From_Source (N));
+
+ if Nkind (N) = N_Selected_Component
+ and then not Inside_A_Generic
+ then
+ Set_Entity (Selector_Name (N), Entity (Subprog));
+ end if;
+
+ -- If need be, rewrite first actual as an explicit dereference
+ -- If the call is overloaded, the rewriting can only be done
+ -- once the primitive operation is identified.
+
+ if Is_Overloaded (Subprog) then
+
+ -- The prefix itself may be overloaded, and its interpretations
+ -- must be propagated to the new actual in the call.
+
+ if Is_Overloaded (Obj) then
+ Save_Interps (Obj, First_Actual);
+ end if;
+
+ Rewrite (First_Actual, Obj);
+
+ elsif not Is_Access_Type (Formal_Type)
+ and then Is_Access_Type (Etype (Obj))
+ then
+ Rewrite (First_Actual,
+ Make_Explicit_Dereference (Sloc (Obj), Obj));
+ Analyze (First_Actual);
+
+ -- If we need to introduce an explicit dereference, verify that
+ -- the resulting actual is compatible with the mode of the formal.
+
+ if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter
+ and then Is_Access_Constant (Etype (Obj))
+ then
+ Error_Msg_NE
+ ("expect variable in call to&", Prefix (N), Entity (Subprog));
+ end if;
+
+ -- Conversely, if the formal is an access parameter and the
+ -- object is not, replace the actual with a 'Access reference.
+ -- Its analysis will check that the object is aliased.
+
+ elsif Is_Access_Type (Formal_Type)
+ and then not Is_Access_Type (Etype (Obj))
+ then
+ Rewrite (First_Actual,
+ Make_Attribute_Reference (Loc,
+ Attribute_Name => Name_Access,
+ Prefix => Relocate_Node (Obj)));
+
+ if not Is_Aliased_View (Obj) then
+ Error_Msg_NE
+ ("object in prefixed call to& must be aliased"
+ & " (RM-2005 4.3.1 (13))",
+ Prefix (First_Actual), Subprog);
+ end if;
+
+ Analyze (First_Actual);
+
+ else
+ if Is_Overloaded (Obj) then
+ Save_Interps (Obj, First_Actual);
+ end if;
+
+ Rewrite (First_Actual, Obj);
+ end if;
+
Rewrite (Node_To_Replace, Call_Node);
- Analyze (Node_To_Replace);
+
+ -- Propagate the interpretations collected in subprog to the new
+ -- function call node, to be resolved from context.
+
+ if Is_Overloaded (Subprog) then
+ Save_Interps (Subprog, Node_To_Replace);
+ else
+ Analyze (Node_To_Replace);
+ end if;
end Complete_Object_Operation;
+ ----------------------
+ -- Report_Ambiguity --
+ ----------------------
+
+ procedure Report_Ambiguity (Op : Entity_Id) is
+ Access_Formal : constant Boolean :=
+ Is_Access_Type (Etype (First_Formal (Op)));
+ Access_Actual : constant Boolean :=
+ Is_Access_Type (Etype (Prefix (N)));
+
+ begin
+ Error_Msg_Sloc := Sloc (Op);
+
+ if Access_Formal and then not Access_Actual then
+ if Nkind (Parent (Op)) = N_Full_Type_Declaration then
+ Error_Msg_N
+ ("\possible interpretation"
+ & " (inherited, with implicit 'Access) #", N);
+ else
+ Error_Msg_N
+ ("\possible interpretation (with implicit 'Access) #", N);
+ end if;
+
+ elsif not Access_Formal and then Access_Actual then
+ if Nkind (Parent (Op)) = N_Full_Type_Declaration then
+ Error_Msg_N
+ ("\possible interpretation"
+ & " ( inherited, with implicit dereference) #", N);
+ else
+ Error_Msg_N
+ ("\possible interpretation (with implicit dereference) #", N);
+ end if;
+
+ else
+ if Nkind (Parent (Op)) = N_Full_Type_Declaration then
+ Error_Msg_N ("\possible interpretation (inherited)#", N);
+ else
+ Error_Msg_N ("\possible interpretation#", N);
+ end if;
+ end if;
+ end Report_Ambiguity;
+
--------------------------------
-- Transform_Object_Operation --
--------------------------------
procedure Transform_Object_Operation
(Call_Node : out Node_Id;
- First_Actual : Node_Id;
- Node_To_Replace : out Node_Id;
- Subprog : Node_Id)
+ Node_To_Replace : out Node_Id)
is
- Actuals : List_Id;
Parent_Node : constant Node_Id := Parent (N);
+ Dummy : constant Node_Id := New_Copy (Obj);
+ -- Placeholder used as a first parameter in the call, replaced
+ -- eventually by the proper object.
+
+ Actuals : List_Id;
+ Actual : Node_Id;
+
begin
- Actuals := New_List (New_Copy_Tree (First_Actual));
+ -- Common case covering 1) Call to a procedure and 2) Call to a
+ -- function that has some additional actuals.
if (Nkind (Parent_Node) = N_Function_Call
or else
Nkind (Parent_Node) = N_Procedure_Call_Statement)
- -- Avoid recursive calls
+ -- N is a selected component node containing the name of the
+ -- subprogram. If N is not the name of the parent node we must
+ -- not replace the parent node by the new construct. This case
+ -- occurs when N is a parameterless call to a subprogram that
+ -- is an actual parameter of a call to another subprogram. For
+ -- example:
+ -- Some_Subprogram (..., Obj.Operation, ...)
- and then N /= First (Parameter_Associations (Parent_Node))
+ and then Name (Parent_Node) = N
then
Node_To_Replace := Parent_Node;
- -- Copy list of actuals in full before attempting to resolve call.
- -- This is necessary to ensure that the chaining of named actuals
- -- that happens during matching is done on a separate copy.
-
- declare
- Actual : Node_Id;
- begin
- Actual := First (Parameter_Associations (Parent_Node));
- while Present (Actual) loop
- declare
- New_Actual : constant Node_Id := New_Copy_Tree (Actual);
-
- begin
- Append (New_Actual, Actuals);
-
- if Nkind (Actual) = N_Function_Call
- and then Is_Overloaded (Name (Actual))
- then
- Save_Interps (Name (Actual), Name (New_Actual));
- end if;
- end;
+ Actuals := Parameter_Associations (Parent_Node);
- Next (Actual);
- end loop;
- end;
+ if Present (Actuals) then
+ Prepend (Dummy, Actuals);
+ else
+ Actuals := New_List (Dummy);
+ end if;
if Nkind (Parent_Node) = N_Procedure_Call_Statement then
Call_Node :=
Make_Procedure_Call_Statement (Loc,
- Name => New_Copy_Tree (Subprog),
+ Name => New_Copy (Subprog),
Parameter_Associations => Actuals);
else
- pragma Assert (Nkind (Parent_Node) = N_Function_Call);
-
Call_Node :=
Make_Function_Call (Loc,
- Name => New_Copy_Tree (Subprog),
+ Name => New_Copy (Subprog),
Parameter_Associations => Actuals);
end if;
- -- Before analysis, the function call appears as an
- -- indexed component.
+ -- Before analysis, the function call appears as an indexed component
+ -- if there are no named associations.
- elsif Nkind (Parent_Node) = N_Indexed_Component then
+ elsif Nkind (Parent_Node) = N_Indexed_Component
+ and then N = Prefix (Parent_Node)
+ then
Node_To_Replace := Parent_Node;
- declare
- Actual : Node_Id;
- New_Act : Node_Id;
- begin
- Actual := First (Expressions (Parent_Node));
- while Present (Actual) loop
- New_Act := New_Copy_Tree (Actual);
- Analyze (New_Act);
- Append (New_Act, Actuals);
- Next (Actual);
- end loop;
- end;
+ Actuals := Expressions (Parent_Node);
+
+ Actual := First (Actuals);
+ while Present (Actual) loop
+ Analyze (Actual);
+ Next (Actual);
+ end loop;
+
+ Prepend (Dummy, Actuals);
Call_Node :=
Make_Function_Call (Loc,
- Name => New_Copy_Tree (Subprog),
+ Name => New_Copy (Subprog),
Parameter_Associations => Actuals);
- -- Parameterless call
+ -- Parameterless call: Obj.F is rewritten as F (Obj)
else
Node_To_Replace := N;
Call_Node :=
Make_Function_Call (Loc,
- Name => New_Copy_Tree (Subprog),
- Parameter_Associations => Actuals);
+ Name => New_Copy (Subprog),
+ Parameter_Associations => New_List (Dummy));
end if;
end Transform_Object_Operation;
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean
is
- Anc_Type : Entity_Id;
- Dummy : Node_Id;
- Hom : Entity_Id;
- Hom_Ref : Node_Id;
- Success : Boolean;
+ Anc_Type : Entity_Id;
+ Matching_Op : Entity_Id := Empty;
+ Error : Boolean;
+
+ procedure Traverse_Homonyms
+ (Anc_Type : Entity_Id;
+ Error : out Boolean);
+ -- Traverse the homonym chain of the subprogram searching for those
+ -- homonyms whose first formal has the Anc_Type's class-wide type,
+ -- or an anonymous access type designating the class-wide type. If an
+ -- ambiguity is detected, then Error is set to True.
+
+ procedure Traverse_Interfaces
+ (Anc_Type : Entity_Id;
+ Error : out Boolean);
+ -- Traverse the list of interfaces, if any, associated with Anc_Type
+ -- and search for acceptable class-wide homonyms associated with each
+ -- interface. If an ambiguity is detected, then Error is set to True.
+
+ -----------------------
+ -- Traverse_Homonyms --
+ -----------------------
+
+ procedure Traverse_Homonyms
+ (Anc_Type : Entity_Id;
+ Error : out Boolean)
+ is
+ Cls_Type : Entity_Id;
+ Hom : Entity_Id;
+ Hom_Ref : Node_Id;
+ Success : Boolean;
- begin
- -- Loop through ancestor types, traverse their homonym chains and
- -- gather all interpretations of the subprogram.
+ begin
+ Error := False;
+
+ Cls_Type := Class_Wide_Type (Anc_Type);
- Anc_Type := Obj_Type;
- loop
Hom := Current_Entity (Subprog);
+
+ -- Find operation whose first parameter is of the class-wide
+ -- type, a subtype thereof, or an anonymous access to same.
+
while Present (Hom) loop
if (Ekind (Hom) = E_Procedure
or else
Ekind (Hom) = E_Function)
+ and then Scope (Hom) = Scope (Anc_Type)
and then Present (First_Formal (Hom))
- and then Etype (First_Formal (Hom)) =
- Class_Wide_Type (Anc_Type)
+ and then
+ (Base_Type (Etype (First_Formal (Hom))) = Cls_Type
+ or else
+ (Is_Access_Type (Etype (First_Formal (Hom)))
+ and then
+ Ekind (Etype (First_Formal (Hom))) =
+ E_Anonymous_Access_Type
+ and then
+ Base_Type
+ (Designated_Type (Etype (First_Formal (Hom)))) =
+ Cls_Type))
then
- Hom_Ref := New_Reference_To (Hom, Loc);
+ Set_Etype (Call_Node, Any_Type);
+ Set_Is_Overloaded (Call_Node, False);
+ Success := False;
- -- When both the type of the object and the type of the
- -- first formal of the primitive operation are tagged
- -- access types, we use a node with the object as first
- -- actual.
+ if No (Matching_Op) then
+ Hom_Ref := New_Reference_To (Hom, Sloc (Subprog));
+ Set_Etype (Call_Node, Any_Type);
+ Set_Parent (Call_Node, Parent (Node_To_Replace));
- if Is_Access_Type (Etype (Obj))
- and then Ekind (Etype (First_Formal (Hom))) =
- E_Anonymous_Access_Type
- then
- -- Allocate the node only once
+ Set_Name (Call_Node, Hom_Ref);
- if not Present (Call_Node_Case) then
- Analyze_Expression (Obj);
- Set_Analyzed (Obj);
+ Analyze_One_Call
+ (N => Call_Node,
+ Nam => Hom,
+ Report => Report_Error,
+ Success => Success,
+ Skip_First => True);
- Transform_Object_Operation (
- Call_Node => Call_Node_Case,
- First_Actual => Obj,
- Node_To_Replace => Dummy,
- Subprog => Subprog);
+ Matching_Op :=
+ Valid_Candidate (Success, Call_Node, Hom);
- Set_Etype (Call_Node_Case, Any_Type);
- Set_Parent (Call_Node_Case, Parent (Node_To_Replace));
+ else
+ Analyze_One_Call
+ (N => Call_Node,
+ Nam => Hom,
+ Report => Report_Error,
+ Success => Success,
+ Skip_First => True);
+
+ if Present (Valid_Candidate (Success, Call_Node, Hom))
+ and then Nkind (Call_Node) /= N_Function_Call
+ then
+ Error_Msg_NE ("ambiguous call to&", N, Hom);
+ Report_Ambiguity (Matching_Op);
+ Report_Ambiguity (Hom);
+ Error := True;
+ return;
end if;
+ end if;
+ end if;
- Set_Name (Call_Node_Case, Hom_Ref);
+ Hom := Homonym (Hom);
+ end loop;
+ end Traverse_Homonyms;
- Analyze_One_Call (
- N => Call_Node_Case,
- Nam => Hom,
- Report => False,
- Success => Success);
+ -------------------------
+ -- Traverse_Interfaces --
+ -------------------------
- if Success then
- Complete_Object_Operation (
- Call_Node => Call_Node_Case,
- Node_To_Replace => Node_To_Replace,
- Subprog => Hom_Ref);
+ procedure Traverse_Interfaces
+ (Anc_Type : Entity_Id;
+ Error : out Boolean)
+ is
+ Intface : Node_Id;
+ Intface_List : constant List_Id :=
+ Abstract_Interface_List (Anc_Type);
- return True;
- end if;
+ begin
+ Error := False;
- -- ??? comment required
+ if Is_Non_Empty_List (Intface_List) then
+ Intface := First (Intface_List);
+ while Present (Intface) loop
- else
- Set_Name (Call_Node, Hom_Ref);
+ -- Look for acceptable class-wide homonyms associated with
+ -- the interface.
+
+ Traverse_Homonyms (Etype (Intface), Error);
+
+ if Error then
+ return;
+ end if;
- Analyze_One_Call (
- N => Call_Node,
- Nam => Hom,
- Report => False,
- Success => Success);
+ -- Continue the search by looking at each of the interface's
+ -- associated interface ancestors.
- if Success then
- Complete_Object_Operation (
- Call_Node => Call_Node,
- Node_To_Replace => Node_To_Replace,
- Subprog => Hom_Ref);
+ Traverse_Interfaces (Etype (Intface), Error);
- return True;
- end if;
+ if Error then
+ return;
end if;
- end if;
- Hom := Homonym (Hom);
- end loop;
+ Next (Intface);
+ end loop;
+ end if;
+ end Traverse_Interfaces;
+
+ -- Start of processing for Try_Class_Wide_Operation
+
+ begin
+ -- Loop through ancestor types (including interfaces), traversing the
+ -- homonym chain of the subprogram, and trying out those homonyms
+ -- whose first formal has the class-wide type of the ancestor, or an
+ -- anonymous access type designating the class-wide type.
- -- Climb to ancestor type if there is one
+ Anc_Type := Obj_Type;
+ loop
+ -- Look for a match among homonyms associated with the ancestor
+
+ Traverse_Homonyms (Anc_Type, Error);
+
+ if Error then
+ return True;
+ end if;
+
+ -- Continue the search for matches among homonyms associated with
+ -- any interfaces implemented by the ancestor.
+
+ Traverse_Interfaces (Anc_Type, Error);
+
+ if Error then
+ return True;
+ end if;
exit when Etype (Anc_Type) = Anc_Type;
Anc_Type := Etype (Anc_Type);
end loop;
- return False;
+ if Present (Matching_Op) then
+ Set_Etype (Call_Node, Etype (Matching_Op));
+ end if;
+
+ return Present (Matching_Op);
end Try_Class_Wide_Operation;
+ -----------------------------------
+ -- Try_One_Prefix_Interpretation --
+ -----------------------------------
+
+ procedure Try_One_Prefix_Interpretation (T : Entity_Id) is
+ begin
+ Obj_Type := T;
+
+ if Is_Access_Type (Obj_Type) then
+ Obj_Type := Designated_Type (Obj_Type);
+ end if;
+
+ if Ekind (Obj_Type) = E_Private_Subtype then
+ Obj_Type := Base_Type (Obj_Type);
+ end if;
+
+ if Is_Class_Wide_Type (Obj_Type) then
+ Obj_Type := Etype (Class_Wide_Type (Obj_Type));
+ end if;
+
+ -- The type may have be obtained through a limited_with clause,
+ -- in which case the primitive operations are available on its
+ -- non-limited view. If still incomplete, retrieve full view.
+
+ if Ekind (Obj_Type) = E_Incomplete_Type
+ and then From_With_Type (Obj_Type)
+ then
+ Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type));
+ end if;
+
+ -- If the object is not tagged, or the type is still an incomplete
+ -- type, this is not a prefixed call.
+
+ if not Is_Tagged_Type (Obj_Type)
+ or else Is_Incomplete_Type (Obj_Type)
+ then
+ return;
+ end if;
+
+ if Try_Primitive_Operation
+ (Call_Node => New_Call_Node,
+ Node_To_Replace => Node_To_Replace)
+ or else
+ Try_Class_Wide_Operation
+ (Call_Node => New_Call_Node,
+ Node_To_Replace => Node_To_Replace)
+ then
+ null;
+ end if;
+ end Try_One_Prefix_Interpretation;
+
-----------------------------
-- Try_Primitive_Operation --
-----------------------------
(Call_Node : Node_Id;
Node_To_Replace : Node_Id) return Boolean
is
- Dummy : Node_Id;
Elmt : Elmt_Id;
Prim_Op : Entity_Id;
- Prim_Op_Ref : Node_Id;
- Success : Boolean;
+ Matching_Op : Entity_Id := Empty;
+ Prim_Op_Ref : Node_Id := Empty;
+
+ Corr_Type : Entity_Id := Empty;
+ -- If the prefix is a synchronized type, the controlling type of
+ -- the primitive operation is the corresponding record type, else
+ -- this is the object type itself.
+
+ Success : Boolean := False;
+
+ function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id;
+ -- For tagged types the candidate interpretations are found in
+ -- the list of primitive operations of the type and its ancestors.
+ -- For formal tagged types we have to find the operations declared
+ -- in the same scope as the type (including in the generic formal
+ -- part) because the type itself carries no primitive operations,
+ -- except for formal derived types that inherit the operations of
+ -- the parent and progenitors.
+
+ function Valid_First_Argument_Of (Op : Entity_Id) return Boolean;
+ -- Verify that the prefix, dereferenced if need be, is a valid
+ -- controlling argument in a call to Op. The remaining actuals
+ -- are checked in the subsequent call to Analyze_One_Call.
+
+ ------------------------------
+ -- Collect_Generic_Type_Ops --
+ ------------------------------
+
+ function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is
+ Bas : constant Entity_Id := Base_Type (T);
+ Candidates : constant Elist_Id := New_Elmt_List;
+ Subp : Entity_Id;
+ Formal : Entity_Id;
+
+ begin
+ if Is_Derived_Type (T) then
+ return Primitive_Operations (T);
+
+ else
+ -- Scan the list of entities declared in the same scope as
+ -- the type. In general this will be an open scope, given that
+ -- the call we are analyzing can only appear within a generic
+ -- declaration or body (either the one that declares T, or a
+ -- child unit).
+
+ Subp := First_Entity (Scope (T));
+ while Present (Subp) loop
+ if Is_Overloadable (Subp) then
+ Formal := First_Formal (Subp);
+
+ if Present (Formal)
+ and then Is_Controlling_Formal (Formal)
+ and then
+ (Base_Type (Etype (Formal)) = Bas
+ or else
+ (Is_Access_Type (Etype (Formal))
+ and then Designated_Type (Etype (Formal)) = Bas))
+ then
+ Append_Elmt (Subp, Candidates);
+ end if;
+ end if;
+
+ Next_Entity (Subp);
+ end loop;
+
+ return Candidates;
+ end if;
+ end Collect_Generic_Type_Ops;
+
+ -----------------------------
+ -- Valid_First_Argument_Of --
+ -----------------------------
+
+ function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is
+ Typ : constant Entity_Id := Etype (First_Formal (Op));
+
+ begin
+ -- Simple case. Object may be a subtype of the tagged type
+ -- or may be the corresponding record of a synchronized type.
+
+ return Obj_Type = Typ
+ or else Base_Type (Obj_Type) = Typ
+
+ or else Corr_Type = Typ
+
+ -- Prefix can be dereferenced
+
+ or else
+ (Is_Access_Type (Corr_Type)
+ and then Designated_Type (Corr_Type) = Typ)
+
+ -- Formal is an access parameter, for which the object
+ -- can provide an access.
+
+ or else
+ (Ekind (Typ) = E_Anonymous_Access_Type
+ and then Designated_Type (Typ) = Base_Type (Corr_Type));
+ end Valid_First_Argument_Of;
+
+ -- Start of processing for Try_Primitive_Operation
begin
- -- Look for the subprogram in the list of primitive operations
+ -- Look for subprograms in the list of primitive operations The name
+ -- must be identical, and the kind of call indicates the expected
+ -- kind of operation (function or procedure). If the type is a
+ -- (tagged) synchronized type, the primitive ops are attached to
+ -- the corresponding record type.
+
+ if Is_Concurrent_Type (Obj_Type) then
+ Corr_Type := Corresponding_Record_Type (Obj_Type);
+ Elmt := First_Elmt (Primitive_Operations (Corr_Type));
+
+ elsif not Is_Generic_Type (Obj_Type) then
+ Corr_Type := Obj_Type;
+ Elmt := First_Elmt (Primitive_Operations (Obj_Type));
+
+ else
+ Corr_Type := Obj_Type;
+ Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type));
+ end if;
- Elmt := First_Elmt (Primitive_Operations (Obj_Type));
while Present (Elmt) loop
Prim_Op := Node (Elmt);
if Chars (Prim_Op) = Chars (Subprog)
and then Present (First_Formal (Prim_Op))
+ and then Valid_First_Argument_Of (Prim_Op)
+ and then
+ (Nkind (Call_Node) = N_Function_Call)
+ = (Ekind (Prim_Op) = E_Function)
then
- Prim_Op_Ref := New_Reference_To (Prim_Op, Loc);
+ -- Ada 2005 (AI-251): If this primitive operation corresponds
+ -- with an immediate ancestor interface there is no need to add
+ -- it to the list of interpretations; the corresponding aliased
+ -- primitive is also in this list of primitive operations and
+ -- will be used instead.
+
+ if (Present (Abstract_Interface_Alias (Prim_Op))
+ and then Is_Ancestor (Find_Dispatching_Type
+ (Alias (Prim_Op)), Corr_Type))
+ or else
- -- When both the type of the object and the type of the first
- -- formal of the primitive operation are tagged access types,
- -- we use a node with the object as first actual.
+ -- Do not consider hidden primitives unless the type is
+ -- in an open scope or we are within an instance, where
+ -- visibility is known to be correct.
- if Is_Access_Type (Etype (Obj))
- and then Ekind (Etype (First_Formal (Prim_Op))) =
- E_Anonymous_Access_Type
+ (Is_Hidden (Prim_Op)
+ and then not Is_Immediately_Visible (Obj_Type)
+ and then not In_Instance)
then
- -- Allocate the node only once
-
- if not Present (Call_Node_Case) then
- Analyze_Expression (Obj);
- Set_Analyzed (Obj);
+ goto Continue;
+ end if;
- Transform_Object_Operation (
- Call_Node => Call_Node_Case,
- First_Actual => Obj,
- Node_To_Replace => Dummy,
- Subprog => Subprog);
+ Set_Etype (Call_Node, Any_Type);
+ Set_Is_Overloaded (Call_Node, False);
- Set_Etype (Call_Node_Case, Any_Type);
- Set_Parent (Call_Node_Case, Parent (Node_To_Replace));
- end if;
+ if No (Matching_Op) then
+ Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog));
+ Candidate := Prim_Op;
- Set_Name (Call_Node_Case, Prim_Op_Ref);
+ Set_Parent (Call_Node, Parent (Node_To_Replace));
- Analyze_One_Call (
- N => Call_Node_Case,
- Nam => Prim_Op,
- Report => False,
- Success => Success);
-
- if Success then
- Complete_Object_Operation (
- Call_Node => Call_Node_Case,
- Node_To_Replace => Node_To_Replace,
- Subprog => Prim_Op_Ref);
+ Set_Name (Call_Node, Prim_Op_Ref);
+ Success := False;
- return True;
- end if;
+ Analyze_One_Call
+ (N => Call_Node,
+ Nam => Prim_Op,
+ Report => Report_Error,
+ Success => Success,
+ Skip_First => True);
- -- Comment required ???
+ Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op);
else
- Set_Name (Call_Node, Prim_Op_Ref);
- Analyze_One_Call (
- N => Call_Node,
- Nam => Prim_Op,
- Report => False,
- Success => Success);
+ -- More than one interpretation, collect for subsequent
+ -- disambiguation. If this is a procedure call and there
+ -- is another match, report ambiguity now.
- if Success then
- Complete_Object_Operation (
- Call_Node => Call_Node,
- Node_To_Replace => Node_To_Replace,
- Subprog => Prim_Op_Ref);
+ Analyze_One_Call
+ (N => Call_Node,
+ Nam => Prim_Op,
+ Report => Report_Error,
+ Success => Success,
+ Skip_First => True);
+ if Present (Valid_Candidate (Success, Call_Node, Prim_Op))
+ and then Nkind (Call_Node) /= N_Function_Call
+ then
+ Error_Msg_NE ("ambiguous call to&", N, Prim_Op);
+ Report_Ambiguity (Matching_Op);
+ Report_Ambiguity (Prim_Op);
return True;
end if;
end if;
end if;
+ <<Continue>>
Next_Elmt (Elmt);
end loop;
- return False;
+ if Present (Matching_Op) then
+ Set_Etype (Call_Node, Etype (Matching_Op));
+ end if;
+
+ return Present (Matching_Op);
end Try_Primitive_Operation;
-- Start of processing for Try_Object_Operation
begin
- if Is_Access_Type (Obj_Type) then
- Obj_Type := Designated_Type (Obj_Type);
- end if;
-
- if Ekind (Obj_Type) = E_Private_Subtype then
- Obj_Type := Base_Type (Obj_Type);
- end if;
-
- if Is_Class_Wide_Type (Obj_Type) then
- Obj_Type := Etype (Class_Wide_Type (Obj_Type));
- end if;
+ Analyze_Expression (Obj);
- -- Analyze the actuals in case of subprogram call
+ -- Analyze the actuals if node is known to be a subprogram call
if Is_Subprg_Call and then N = Name (Parent (N)) then
Actual := First (Parameter_Associations (Parent (N)));
end loop;
end if;
- -- If the object is of an Access type, explicit dereference is
- -- required.
+ -- Build a subprogram call node, using a copy of Obj as its first
+ -- actual. This is a placeholder, to be replaced by an explicit
+ -- dereference when needed.
+
+ Transform_Object_Operation
+ (Call_Node => New_Call_Node,
+ Node_To_Replace => Node_To_Replace);
+
+ Set_Etype (New_Call_Node, Any_Type);
+ Set_Etype (Subprog, Any_Type);
+ Set_Parent (New_Call_Node, Parent (Node_To_Replace));
+
+ if not Is_Overloaded (Obj) then
+ Try_One_Prefix_Interpretation (Obj_Type);
- if Is_Access_Type (Etype (Obj)) then
- First_Actual :=
- Make_Explicit_Dereference (Sloc (Obj), Obj);
- Set_Etype (First_Actual, Obj_Type);
else
- First_Actual := Obj;
+ declare
+ I : Interp_Index;
+ It : Interp;
+ begin
+ Get_First_Interp (Obj, I, It);
+ while Present (It.Nam) loop
+ Try_One_Prefix_Interpretation (It.Typ);
+ Get_Next_Interp (I, It);
+ end loop;
+ end;
end if;
- Analyze_Expression (First_Actual);
- Set_Analyzed (First_Actual);
+ if Etype (New_Call_Node) /= Any_Type then
+ Complete_Object_Operation
+ (Call_Node => New_Call_Node,
+ Node_To_Replace => Node_To_Replace);
+ return True;
- -- Build a subprogram call node
+ elsif Present (Candidate) then
- Transform_Object_Operation (
- Call_Node => Call_Node,
- First_Actual => First_Actual,
- Node_To_Replace => Node_To_Replace,
- Subprog => Subprog);
+ -- The argument list is not type correct. Re-analyze with error
+ -- reporting enabled, and use one of the possible candidates.
+ -- In all_errors mode, re-analyze all failed interpretations.
- Set_Etype (Call_Node, Any_Type);
- Set_Parent (Call_Node, Parent (Node_To_Replace));
+ if All_Errors_Mode then
+ Report_Error := True;
+ if Try_Primitive_Operation
+ (Call_Node => New_Call_Node,
+ Node_To_Replace => Node_To_Replace)
- return
- Try_Primitive_Operation
- (Call_Node => Call_Node,
- Node_To_Replace => Node_To_Replace)
- or else
- Try_Class_Wide_Operation
- (Call_Node => Call_Node,
- Node_To_Replace => Node_To_Replace);
+ or else
+ Try_Class_Wide_Operation
+ (Call_Node => New_Call_Node,
+ Node_To_Replace => Node_To_Replace)
+ then
+ null;
+ end if;
+
+ else
+ Analyze_One_Call
+ (N => New_Call_Node,
+ Nam => Candidate,
+ Report => True,
+ Success => Success,
+ Skip_First => True);
+ end if;
+
+ return True; -- No need for further errors.
+
+ else
+ -- There was no candidate operation, so report it as an error
+ -- in the caller: Analyze_Selected_Component.
+
+ return False;
+ end if;
end Try_Object_Operation;
end Sem_Ch4;
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