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Diffstat (limited to 'gcc-4.3.1/gcc/ada/sem_disp.ads')
| -rw-r--r-- | gcc-4.3.1/gcc/ada/sem_disp.ads | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/gcc-4.3.1/gcc/ada/sem_disp.ads b/gcc-4.3.1/gcc/ada/sem_disp.ads new file mode 100644 index 000000000..496a00341 --- /dev/null +++ b/gcc-4.3.1/gcc/ada/sem_disp.ads @@ -0,0 +1,96 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ D I S P -- +-- -- +-- S p e c -- +-- -- +-- 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 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 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. -- +-- -- +------------------------------------------------------------------------------ + +-- 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 Override_Dispatching_Operation + (Tagged_Type : Entity_Id; + Prev_Op : Entity_Id; + New_Op : Entity_Id); + -- Replace an implicit dispatching operation with an explicit one. + -- Prev_Op is an inherited primitive operation which is overridden + -- by the explicit declaration of New_Op. + + 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; |