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 Free Software Foundation, Inc.
5
6This file is part of GNU CC.
7
8GNU CC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 2, or (at your option)
11any later version.
12
13GNU CC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GNU CC; see the file COPYING.  If not, write to
20the Free Software Foundation, 59 Temple Place - Suite 330,
21Boston, MA 02111-1307, USA.  */
22
23
24#include "config.h"
25#include "system.h"
26#include "rtl.h"
27#include "tree.h"
28#include "flags.h"
29#include "expr.h"
30#include "cp-tree.h"
31#include "toplev.h"
32#include "except.h"
33#include "tm_p.h"
34
35/* Hook used by output_constant to expand language-specific
36   constants.  */
37
38tree
39cplus_expand_constant (cst)
40     tree cst;
41{
42  switch (TREE_CODE (cst))
43    {
44    case PTRMEM_CST:
45      {
46	tree type = TREE_TYPE (cst);
47	tree member;
48
49	/* Find the member.  */
50	member = PTRMEM_CST_MEMBER (cst);
51
52	if (TREE_CODE (member) == FIELD_DECL)
53	  {
54	    /* Find the offset for the field.  */
55	    tree offset = byte_position (member);
56	    cst = fold (build1 (NOP_EXPR, type, offset));
57	  }
58	else
59	  {
60	    tree delta;
61	    tree pfn;
62
63	    expand_ptrmemfunc_cst (cst, &delta, &pfn);
64	    cst = build_ptrmemfunc1 (type, delta, pfn);
65	  }
66      }
67      break;
68
69    default:
70      /* There's nothing to do.  */
71      break;
72    }
73
74  return cst;
75}
76
77/* Hook used by expand_expr to expand language-specific tree codes.  */
78
79rtx
80cxx_expand_expr (exp, target, tmode, modifier)
81     tree exp;
82     rtx target;
83     enum machine_mode tmode;
84     int modifier;  /* Actually an enum expand_modifier.  */
85{
86  tree type = TREE_TYPE (exp);
87  register enum machine_mode mode = TYPE_MODE (type);
88  register enum tree_code code = TREE_CODE (exp);
89  rtx ret;
90
91  /* No sense saving up arithmetic to be done
92     if it's all in the wrong mode to form part of an address.
93     And force_operand won't know whether to sign-extend or zero-extend.  */
94
95  if (mode != Pmode && modifier == EXPAND_SUM)
96    modifier = EXPAND_NORMAL;
97
98  switch (code)
99    {
100    case PTRMEM_CST:
101      return expand_expr (cplus_expand_constant (exp),
102			  target, tmode, modifier);
103
104    case OFFSET_REF:
105      /* Offset refs should not make it through to here.  */
106      abort ();
107      return const0_rtx;
108
109    case THROW_EXPR:
110      expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode, 0);
111      return const0_rtx;
112
113    case MUST_NOT_THROW_EXPR:
114      expand_eh_region_start ();
115      ret = expand_expr (TREE_OPERAND (exp, 0), target, tmode, modifier);
116      expand_eh_region_end_must_not_throw (build_call (terminate_node, 0));
117      return ret;
118
119    case EMPTY_CLASS_EXPR:
120      /* We don't need to generate any code for an empty class.  */
121      return const0_rtx;
122
123    default:
124      return c_expand_expr (exp, target, tmode, modifier);
125    }
126  abort ();
127  /* NOTREACHED */
128  return NULL;
129}
130