------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ D I S P -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2002 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;