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diff --git a/gcc/ada/itypes.ads b/gcc/ada/itypes.ads new file mode 100644 index 00000000000..b44a28ee7d8 --- /dev/null +++ b/gcc/ada/itypes.ads @@ -0,0 +1,115 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- I T Y P E S -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.22 $ -- +-- -- +-- Copyright (C) 1992,1993,1994,1995,1996 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 declarations for handling of implicit types + +with Einfo; use Einfo; +with Sem_Util; use Sem_Util; +with Types; use Types; + +package Itypes is + + -------------------- + -- Implicit Types -- + -------------------- + + -- Implicit types are types and subtypes created by the semantic phase + -- or the expander to reflect the underlying semantics. These could be + -- generated by building trees for corresponding declarations and then + -- analyzing these trees, but there are three reasons for not doing this: + + -- 1. The declarations would require more tree nodes + + -- 2. In some cases, the elaboration of these types is associated + -- with internal nodes in the tree. + + -- 3. For some types, notably class wide types, there is no Ada + -- declaration that would correspond to the desired entity. + + -- So instead, implicit types are constructed by simply creating an + -- appropriate entity with the help of routines in this package. These + -- entities are fully decorated, as described in Einfo (just as though + -- they had been created by the normal analysis procedure). + + -- The type declaration declaring an Itype must be analyzed with checks + -- off because this declaration has not been inserted in the tree (if it + -- has been then it is not an itype), and hence checks that would be + -- generated during the analysis cannot be inserted in the tree. At any + -- rate, itype analysis should always be done with checks off, otherwise + -- duplicate checks will most likely be emitted. + + -- Unlike types declared explicitly, implicit types are defined on first + -- use, which means that Gigi detects the use of such types, and defines + -- them at the point of the first use automatically. + + -- Although Itypes are not explicitly declared, they are associated with + -- a specific node in the tree (roughly the node that caused them to be + -- created), via the Associated_Node_For_Itype field. This association is + -- used particularly by New_Copy_Tree, which uses it to determine whether + -- or not to copy a referenced Itype. If the associated node is part of + -- the tree to be copied by New_Copy_Tree, then (since the idea of the + -- call to New_Copy_Tree is to create a complete duplicate of a tree, + -- as though it had appeared separately int he source), the Itype in + -- question is duplicated as part of the New_Copy_Tree processing. + + ----------------- + -- Subprograms -- + ----------------- + + function Create_Itype + (Ekind : Entity_Kind; + Related_Nod : Node_Id; + Related_Id : Entity_Id := Empty; + Suffix : Character := ' '; + Suffix_Index : Nat := 0; + Scope_Id : Entity_Id := Current_Scope) + return Entity_Id; + -- Used to create a new Itype. + -- + -- Related_Nod is the node for which this Itype was created. It is + -- set as the Associated_Node_For_Itype of the new itype. The Sloc of + -- the new Itype is that of this node. + -- + -- Related_Id is present only if the implicit type name may be referenced + -- as a public symbol, and thus needs a unique external name. The name + -- is created by a call to: + -- + -- New_External_Name (Chars (Related_Id), Suffix, Suffix_Index, 'T') + -- + -- If the implicit type does not need an external name, then the + -- Related_Id parameter is omitted (and hence Empty). In this case + -- Suffix and Suffix_Index are ignored and the implicit type name is + -- created by a call to New_Internal_Name ('T'). + -- + -- Note that in all cases, the name starts with "T". This is used + -- to identify implicit types in the error message handling circuits. + -- + -- The Scope_Id parameter specifies the scope of the created type, and + -- is normally the Current_Scope as shown, but can be set otherwise. + +end Itypes; |