| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ D I S P -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.16 $ -- |
| -- -- |
| -- 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. -- |
| -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- 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; |
