-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2008, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- The following data structures establish a mapping between nodes and
-- their interpretations. An overloaded node has an entry in Interp_Map,
-- which in turn contains a pointer into the All_Interp array. The
- -- interpretations of a given node are contiguous in All_Interp. Each
- -- set of interpretations is terminated with the marker No_Interp.
- -- In order to speed up the retrieval of the interpretations of an
- -- overloaded node, the Interp_Map table is accessed by means of a simple
- -- hashing scheme, and the entries in Interp_Map are chained. The heads
- -- of clash lists are stored in array Headers.
+ -- interpretations of a given node are contiguous in All_Interp. Each set
+ -- of interpretations is terminated with the marker No_Interp. In order to
+ -- speed up the retrieval of the interpretations of an overloaded node, the
+ -- Interp_Map table is accessed by means of a simple hashing scheme, and
+ -- the entries in Interp_Map are chained. The heads of clash lists are
+ -- stored in array Headers.
-- Headers Interp_Map All_Interp
-- Operator Overloading --
--------------------------
- -- The visibility of operators is handled differently from that of
- -- other entities. We do not introduce explicit versions of primitive
- -- operators for each type definition. As a result, there is only one
- -- entity corresponding to predefined addition on all numeric types, etc.
- -- The back-end resolves predefined operators according to their type.
- -- The visibility of primitive operations then reduces to the visibility
- -- of the resulting type: (a + b) is a legal interpretation of some
- -- primitive operator + if the type of the result (which must also be
- -- the type of a and b) is directly visible (i.e. either immediately
- -- visible or use-visible.)
+ -- The visibility of operators is handled differently from that of other
+ -- entities. We do not introduce explicit versions of primitive operators
+ -- for each type definition. As a result, there is only one entity
+ -- corresponding to predefined addition on all numeric types, etc. The
+ -- back-end resolves predefined operators according to their type. The
+ -- visibility of primitive operations then reduces to the visibility of the
+ -- resulting type: (a + b) is a legal interpretation of some primitive
+ -- operator + if the type of the result (which must also be the type of a
+ -- and b) is directly visible (either immediately visible or use-visible).
-- User-defined operators are treated like other functions, but the
-- visibility of these user-defined operations must be special-cased
begin
-- If either operand missing, then this is an error, but ignore it (and
-- pretend we have a cover) if errors already detected, since this may
- -- simply mean we have malformed trees.
+ -- simply mean we have malformed trees or a semantic error upstream.
if No (T1) or else No (T2) then
if Total_Errors_Detected /= 0 then
or else Scope (T1) /= Scope (T2));
end if;
- -- Literals are compatible with types in a given "class"
+ -- Literals are compatible with types in a given "class"
elsif (T2 = Universal_Integer and then Is_Integer_Type (T1))
or else (T2 = Universal_Real and then Is_Real_Type (T1))
then
return True;
- -- The context may be class wide
+ -- The context may be class wide, and a class-wide type is
+ -- compatible with any member of the class.
elsif Is_Class_Wide_Type (T1)
and then Is_Ancestor (Root_Type (T1), T2)
then
return True;
- -- Ada 2005 (AI-345): A class-wide abstract interface type T1 covers a
- -- task_type or protected_type implementing T1
+ -- Ada 2005 (AI-345): A class-wide abstract interface type covers a
+ -- task_type or protected_type that implements the interface.
elsif Ada_Version >= Ada_05
and then Is_Class_Wide_Type (T1)
then
return True;
- -- Some contexts require a class of types rather than a specific type
+ -- Some contexts require a class of types rather than a specific type.
+ -- For example, conditions require any boolean type, fixed point
+ -- attributes require some real type, etc. The built-in types Any_XXX
+ -- represent these classes.
elsif (T1 = Any_Integer and then Is_Integer_Type (T2))
or else (T1 = Any_Boolean and then Is_Boolean_Type (T2))
then
return Covers (Corresponding_Remote_Type (T1), T2);
+ -- and conversely.
+
elsif Is_Record_Type (T2)
and then (Is_Remote_Call_Interface (T2)
or else Is_Remote_Types (T2))
then
return Covers (Corresponding_Remote_Type (T2), T1);
+ -- Synchronized types are represented at run time by their corresponding
+ -- record type. During expansion one is replaced with the other, but
+ -- they are compatible views of the same type.
+
+ elsif Is_Record_Type (T1)
+ and then Is_Concurrent_Type (T2)
+ and then Present (Corresponding_Record_Type (T2))
+ then
+ return Covers (T1, Corresponding_Record_Type (T2));
+
+ elsif Is_Concurrent_Type (T1)
+ and then Present (Corresponding_Record_Type (T1))
+ and then Is_Record_Type (T2)
+ then
+ return Covers (Corresponding_Record_Type (T1), T2);
+
+ -- During analysis, an attribute reference 'Access has a special type
+ -- kind: Access_Attribute_Type, to be replaced eventually with the type
+ -- imposed by context.
+
elsif Ekind (T2) = E_Access_Attribute_Type
and then (Ekind (BT1) = E_General_Access_Type
- or else Ekind (BT1) = E_Access_Type)
+ or else
+ Ekind (BT1) = E_Access_Type)
and then Covers (Designated_Type (T1), Designated_Type (T2))
then
-- If the target type is a RACW type while the source is an access
return True;
+ -- Ditto for allocators, which eventually resolve to the context type
+
elsif Ekind (T2) = E_Allocator_Type
and then Is_Access_Type (T1)
then
-- A packed array type covers its corresponding non-packed type. This is
-- not legitimate Ada, but allows the omission of a number of otherwise
-- useless unchecked conversions, and since this can only arise in
- -- (known correct) expanded code, no harm is done
+ -- (known correct) expanded code, no harm is done.
elsif Is_Array_Type (T2)
and then Is_Packed (T2)
return True;
-- Ada 2005 (AI-50217): Additional branches to make the shadow entity
- -- compatible with its real entity.
+ -- obtained through a limited_with compatible with its real entity.
elsif From_With_Type (T1) then
-- If units in the context have Limited_With clauses on each other,
-- either type might have a limited view. Checks performed elsewhere
- -- verify that the context type is the non-limited view.
+ -- verify that the context type is the nonlimited view.
if Is_Incomplete_Type (T2) then
return Covers (T1, Get_Full_View (Non_Limited_View (T2)));
-- Ada 2005 (AI-423): Coverage of formal anonymous access types
-- and actual anonymous access types in the context of generic
- -- instantiation. We have the following situation:
+ -- instantiations. We have the following situation:
-- generic
-- type Formal is private;
then
return True;
- -- Otherwise it doesn't cover!
+ -- Otherwise, types are not compatible!
else
return False;
function Disambiguate
(N : Node_Id;
I1, I2 : Interp_Index;
- Typ : Entity_Id)
- return Interp
+ Typ : Entity_Id) return Interp
is
I : Interp_Index;
It : Interp;
-- Determine whether one of the candidates is an operation inherited by
-- a type that is derived from an actual in an instantiation.
- function In_Generic_Actual (Exp : Node_Id) return Boolean;
- -- Determine whether the expression is part of a generic actual. At
- -- the time the actual is resolved the scope is already that of the
- -- instance, but conceptually the resolution of the actual takes place
- -- in the enclosing context, and no special disambiguation rules should
- -- be applied.
-
function Is_Actual_Subprogram (S : Entity_Id) return Boolean;
-- Determine whether a subprogram is an actual in an enclosing instance.
-- An overloading between such a subprogram and one declared outside the
-- for special handling of expressions with universal operands, see
-- comments to Has_Abstract_Interpretation below.
- ------------------------
- -- In_Generic_Actual --
- ------------------------
-
- function In_Generic_Actual (Exp : Node_Id) return Boolean is
- Par : constant Node_Id := Parent (Exp);
-
- begin
- if No (Par) then
- return False;
-
- elsif Nkind (Par) in N_Declaration then
- if Nkind (Par) = N_Object_Declaration
- or else Nkind (Par) = N_Object_Renaming_Declaration
- then
- return Present (Corresponding_Generic_Association (Par));
- else
- return False;
- end if;
-
- elsif Nkind (Par) in N_Statement_Other_Than_Procedure_Call then
- return False;
-
- else
- return In_Generic_Actual (Parent (Par));
- end if;
- end In_Generic_Actual;
-
---------------------------
-- Inherited_From_Actual --
---------------------------
return In_Open_Scopes (Scope (S))
and then
(Is_Generic_Instance (Scope (S))
- or else Is_Wrapper_Package (Scope (S)));
+ or else Is_Wrapper_Package (Scope (S)));
end Is_Actual_Subprogram;
-------------
return T1 = T2
or else
(Is_Numeric_Type (T2)
- and then
- (T1 = Universal_Real or else T1 = Universal_Integer));
+ and then (T1 = Universal_Real or else T1 = Universal_Integer));
end Matches;
------------------------
elsif Present (Act2)
and then Nkind (Act2) in N_Op
and then Is_Overloaded (Act2)
- and then (Nkind (Right_Opnd (Act2)) = N_Integer_Literal
- or else
- Nkind (Right_Opnd (Act2)) = N_Real_Literal)
+ and then Nkind_In (Right_Opnd (Act2), N_Integer_Literal,
+ N_Real_Literal)
and then Has_Compatible_Type (Act2, Standard_Boolean)
then
-- The preference rule on the first actual is not
and then Present (Access_Definition (Parent (N)))
then
if Ekind (It1.Typ) = E_Anonymous_Access_Type
- or else Ekind (It1.Typ) = E_Anonymous_Access_Subprogram_Type
+ or else
+ Ekind (It1.Typ) = E_Anonymous_Access_Subprogram_Type
then
if Ekind (It2.Typ) = Ekind (It1.Typ) then
-- True ambiguity
return No_Interp;
+
else
return It1;
end if;
elsif Ekind (It2.Typ) = E_Anonymous_Access_Type
- or else Ekind (It2.Typ) = E_Anonymous_Access_Subprogram_Type
+ or else
+ Ekind (It2.Typ) = E_Anonymous_Access_Subprogram_Type
then
return It2;
- else
-
- -- No legal interpretation.
+ -- No legal interpretation
+ else
return No_Interp;
end if;
end if;
Map_Ptr := Headers (Hash (O_N));
- while Present (Interp_Map.Table (Map_Ptr).Node) loop
+ while Map_Ptr /= No_Entry loop
if Interp_Map.Table (Map_Ptr).Node = O_N then
Int_Ind := Interp_Map.Table (Map_Ptr).Index;
It := All_Interp.Table (Int_Ind);
-------------------------
function Has_Compatible_Type
- (N : Node_Id;
- Typ : Entity_Id)
- return Boolean
+ (N : Node_Id;
+ Typ : Entity_Id) return Boolean
is
I : Interp_Index;
It : Interp;
-- Start of processing for Interface_Present_In_Ancestor
begin
+ -- Iface might be a class-wide subtype, so we have to apply Base_Type
+
if Is_Class_Wide_Type (Iface) then
- Iface_Typ := Etype (Iface);
+ Iface_Typ := Etype (Base_Type (Iface));
else
Iface_Typ := Iface;
end if;
return Typ;
end Intersect_Types;
+ -----------------------
+ -- In_Generic_Actual --
+ -----------------------
+
+ function In_Generic_Actual (Exp : Node_Id) return Boolean is
+ Par : constant Node_Id := Parent (Exp);
+
+ begin
+ if No (Par) then
+ return False;
+
+ elsif Nkind (Par) in N_Declaration then
+ if Nkind (Par) = N_Object_Declaration then
+ return Present (Corresponding_Generic_Association (Par));
+ else
+ return False;
+ end if;
+
+ elsif Nkind (Par) = N_Object_Renaming_Declaration then
+ return Present (Corresponding_Generic_Association (Par));
+
+ elsif Nkind (Par) in N_Statement_Other_Than_Procedure_Call then
+ return False;
+
+ else
+ return In_Generic_Actual (Parent (Par));
+ end if;
+ end In_Generic_Actual;
+
-----------------
-- Is_Ancestor --
-----------------
---------------------------
function Is_Invisible_Operator
- (N : Node_Id;
- T : Entity_Id)
- return Boolean
+ (N : Node_Id;
+ T : Entity_Id) return Boolean
is
Orig_Node : constant Node_Id := Original_Node (N);
and then Base_Type (T1) = Base_Type (T)
and then Is_Numeric_Type (T);
- -- for division and multiplication, a user-defined function does
- -- not match the predefined universal_fixed operation, except in
- -- Ada83 mode.
+ -- For division and multiplication, a user-defined function does not
+ -- match the predefined universal_fixed operation, except in Ada 83.
elsif Op_Name = Name_Op_Divide then
return (Base_Type (T1) = Base_Type (T2)
II : Interp_Index;
begin
- -- Find end of Interp list and copy downward to erase the discarded one
+ -- Find end of interp list and copy downward to erase the discarded one
II := I + 1;
while Present (All_Interp.Table (II).Typ) loop
All_Interp.Table (J - 1) := All_Interp.Table (J);
end loop;
- -- Back up interp. index to insure that iterator will pick up next
+ -- Back up interp index to insure that iterator will pick up next
-- available interpretation.
I := I - 1;
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