xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/cp/expr.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Convert language-specific tree expression to rtl instructions,
2    for GNU compiler.
3    Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4    2000, 2001, 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12 
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 GNU General Public License for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 #include "rtl.h"
28 #include "tree.h"
29 #include "flags.h"
30 #include "expr.h"
31 #include "cp-tree.h"
32 #include "toplev.h"
33 #include "except.h"
34 #include "tm_p.h"
35 
36 /* Expand C++-specific constants.  Currently, this means PTRMEM_CST.  */
37 
38 tree
39 cplus_expand_constant (tree cst)
40 {
41   switch (TREE_CODE (cst))
42     {
43     case PTRMEM_CST:
44       {
45 	tree type = TREE_TYPE (cst);
46 	tree member;
47 
48 	/* Find the member.  */
49 	member = PTRMEM_CST_MEMBER (cst);
50 
51 	if (TREE_CODE (member) == FIELD_DECL)
52 	  {
53 	    /* Find the offset for the field.  */
54 	    cst = byte_position (member);
55 	    while (!same_type_p (DECL_CONTEXT (member),
56 				 TYPE_PTRMEM_CLASS_TYPE (type)))
57 	      {
58 		/* The MEMBER must have been nestled within an
59 		   anonymous aggregate contained in TYPE.  Find the
60 		   anonymous aggregate.  */
61 		member = lookup_anon_field (TYPE_PTRMEM_CLASS_TYPE (type),
62 					    DECL_CONTEXT (member));
63 		cst = size_binop (PLUS_EXPR, cst, byte_position (member));
64 	      }
65 	    cst = fold (build_nop (type, cst));
66 	  }
67 	else
68 	  {
69 	    tree delta;
70 	    tree pfn;
71 
72 	    expand_ptrmemfunc_cst (cst, &delta, &pfn);
73 	    cst = build_ptrmemfunc1 (type, delta, pfn);
74 	  }
75       }
76       break;
77 
78     default:
79       /* There's nothing to do.  */
80       break;
81     }
82 
83   return cst;
84 }
85