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Diffstat (limited to 'gcc-4.9/gcc/ada/sem_disp.ads')
| -rw-r--r-- | gcc-4.9/gcc/ada/sem_disp.ads | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/ada/sem_disp.ads b/gcc-4.9/gcc/ada/sem_disp.ads new file mode 100644 index 000000000..ff1ebc4d7 --- /dev/null +++ b/gcc-4.9/gcc/ada/sem_disp.ads @@ -0,0 +1,137 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ D I S P -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2012, 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. If the tagged type associated with + -- Subp is a concurrent type (case that occurs when the type is declared in + -- a generic because the analysis of generics disables generation of the + -- corresponding record) then this routine does does not add "Subp" to the + -- list of primitive operations but leaves Subp decorated as dispatching + -- operation to enable checks associated with the Object.Operation notation + + 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 Covers_Some_Interface (Prim : Entity_Id) return Boolean; + -- Returns true if Prim covers some interface primitive of its associated + -- tagged type. The tagged type of Prim must be frozen when this function + -- is invoked. + + 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. Returns Empty if Subp is not a + -- dispatching operation. + + function Find_Primitive_Covering_Interface + (Tagged_Type : Entity_Id; + Iface_Prim : Entity_Id) return Entity_Id; + -- Search in the homonym chain for the primitive of Tagged_Type that covers + -- Iface_Prim. The homonym chain traversal is required to catch primitives + -- associated with the partial view of private types when processing the + -- corresponding full view. If the entity is not found then search for it + -- in the list of primitives of Tagged_Type. This latter search is needed + -- when the interface primitive is covered by a private subprogram. If the + -- primitive has not been covered yet then return the entity that will be + -- overridden when the primitive is covered (that is, return the entity + -- whose alias attribute references the interface primitive). If none of + -- these entities is found then return Empty. + + type Subprogram_List is array (Nat range <>) of Entity_Id; + -- Type returned by Inherited_Subprograms function + + function Inherited_Subprograms (S : Entity_Id) return Subprogram_List; + -- Given the spec of a subprogram, this function gathers any inherited + -- subprograms from direct inheritance or via interfaces. The list is + -- a list of entity id's of the specs of inherited subprograms. Returns + -- a null array if passed an Empty spec id. Note that the returned array + -- only includes subprograms and generic subprograms (and excludes any + -- other inherited entities, in particular enumeration literals). + + 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_Null_Interface_Primitive (E : Entity_Id) return Boolean; + -- Returns True if E is a null procedure that is an interface primitive + + 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; + Is_Wrapper : Boolean := False); + -- 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. Is_Wrapper is True when + -- New_Op is an internally generated wrapper of a controlling function. + + 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; |