+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S E M _ D I S P --
--- --
--- S p e c --
--- --
--- $Revision: 1.1.16.2 $
--- --
--- Copyright (C) 1992-1999 Free Software Foundation, Inc. --
--- --
--- GNAT is free software; you can redistribute it and/or modify it under --
--- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
--- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
--- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
--- --
--- GNAT was originally developed by the GNAT team at New York University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
--- This package contains routines involved in tagged types and dynamic
--- dispatching.
-
-with Types; use Types;
-package Sem_Disp is
-
- procedure Check_Controlling_Formals (Typ : Entity_Id; Subp : Entity_Id);
- -- Check that all controlling parameters of Subp are of type Typ,
- -- that defaults for controlling parameters are tag-indeterminate,
- -- and that the nominal subtype of the parameters and result
- -- statically match the first subtype of the controlling type.
-
- procedure Check_Dispatching_Call (N : Node_Id);
- -- Check if a call is a dispatching call. The subprogram is known to
- -- be a dispatching operation. The call is dispatching if all the
- -- controlling actuals are dynamically tagged. This procedure is called
- -- after overload resolution, so the call is known to be unambiguous.
-
- procedure Check_Dispatching_Operation (Subp, Old_Subp : Entity_Id);
- -- Add "Subp" to the list of primitive operations of the corresponding type
- -- if it has a parameter of this type and is defined at a proper place for
- -- primitive operations. (new primitives are only defined in package spec,
- -- overridden operation can be defined in any scope). If Old_Subp is not
- -- Empty we are in the overriding case.
-
- procedure Check_Operation_From_Incomplete_Type
- (Subp : Entity_Id;
- Typ : Entity_Id);
- -- If a primitive operation was defined for the incomplete view of the
- -- type, and the full type declaration is a derived type definition,
- -- the operation may override an inherited one.
-
- procedure Check_Operation_From_Private_View (Subp, Old_Subp : Entity_Id);
- -- Add "Old_Subp" to the list of primitive operations of the corresponding
- -- tagged type if it is the full view of a private tagged type. The Alias
- -- of "OldSubp" is adjusted to point to the inherited procedure of the
- -- full view because it is always this one which has to be called.
-
- function Find_Controlling_Arg (N : Node_Id) return Node_Id;
- -- Returns the actual controlling argument if N is dynamically tagged,
- -- and Empty if it is not dynamically tagged.
-
- function Find_Dispatching_Type (Subp : Entity_Id) return Entity_Id;
- -- Check whether a subprogram is dispatching, and find the tagged
- -- type of the controlling argument or arguments.
-
- function Is_Dynamically_Tagged (N : Node_Id) return Boolean;
- -- Used to determine whether a call is dispatching, i.e. if is an
- -- an expression of a class_Wide type, or a call to a function with
- -- controlling result where at least one operand is dynamically tagged.
-
- function Is_Tag_Indeterminate (N : Node_Id) return Boolean;
- -- An expression is tag-indeterminate if it is a call that dispatches
- -- on result, and all controlling operands are also indeterminate.
- -- Such a function call may inherit a tag from an enclosing call.
-
- procedure Propagate_Tag (Control : Node_Id; Actual : Node_Id);
- -- If a function call is tag-indeterminate, its controlling argument is
- -- found in the context; either an enclosing call, or the left-hand side
- -- of the enclosing assignment statement. The tag must be propagated
- -- recursively to the tag-indeterminate actuals of the call.
-
-end Sem_Disp;