darwin-c.c revision 132718 
1/* Darwin support needed only by C/C++ frontends.
2   Copyright (C) 2001, 2003  Free Software Foundation, Inc.
3   Contributed by Apple Computer Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING.  If not, write to
19the Free Software Foundation, 59 Temple Place - Suite 330,
20Boston, MA 02111-1307, USA.  */
21
22#include "config.h"
23#include "system.h"
24#include "coretypes.h"
25#include "tm.h"
26#include "cpplib.h"
27#include "tree.h"
28#include "c-pragma.h"
29#include "c-tree.h"
30#include "toplev.h"
31#include "tm_p.h"
32
33/* Pragmas.  */
34
35#define BAD(msgid) do { warning (msgid); return; } while (0)
36
37/* Maintain a small stack of alignments.  This is similar to pragma
38   pack's stack, but simpler.  */
39
40static void push_field_alignment (int);
41static void pop_field_alignment (void);
42
43typedef struct align_stack
44{
45  int alignment;
46  struct align_stack * prev;
47} align_stack;
48
49static struct align_stack * field_align_stack = NULL;
50
51static void
52push_field_alignment (int bit_alignment)
53{
54  align_stack *entry = (align_stack *) xmalloc (sizeof (align_stack));
55
56  entry->alignment = maximum_field_alignment;
57  entry->prev = field_align_stack;
58  field_align_stack = entry;
59
60  maximum_field_alignment = bit_alignment;
61}
62
63static void
64pop_field_alignment (void)
65{
66  if (field_align_stack)
67    {
68      align_stack *entry = field_align_stack;
69
70      maximum_field_alignment = entry->alignment;
71      field_align_stack = entry->prev;
72      free (entry);
73    }
74  else
75    error ("too many #pragma options align=reset");
76}
77
78/* Handlers for Darwin-specific pragmas.  */
79
80void
81darwin_pragma_ignore (cpp_reader *pfile ATTRIBUTE_UNUSED)
82{
83  /* Do nothing.  */
84}
85
86/* #pragma options align={mac68k|power|reset} */
87
88void
89darwin_pragma_options (cpp_reader *pfile ATTRIBUTE_UNUSED)
90{
91  const char *arg;
92  tree t, x;
93
94  if (c_lex (&t) != CPP_NAME)
95    BAD ("malformed '#pragma options', ignoring");
96  arg = IDENTIFIER_POINTER (t);
97  if (strcmp (arg, "align"))
98    BAD ("malformed '#pragma options', ignoring");
99  if (c_lex (&t) != CPP_EQ)
100    BAD ("malformed '#pragma options', ignoring");
101  if (c_lex (&t) != CPP_NAME)
102    BAD ("malformed '#pragma options', ignoring");
103
104  if (c_lex (&x) != CPP_EOF)
105    warning ("junk at end of '#pragma options'");
106
107  arg = IDENTIFIER_POINTER (t);
108  if (!strcmp (arg, "mac68k"))
109    push_field_alignment (16);
110  else if (!strcmp (arg, "power"))
111    push_field_alignment (0);
112  else if (!strcmp (arg, "reset"))
113    pop_field_alignment ();
114  else
115    warning ("malformed '#pragma options align={mac68k|power|reset}', ignoring");
116}
117
118/* #pragma unused ([var {, var}*]) */
119
120void
121darwin_pragma_unused (cpp_reader *pfile ATTRIBUTE_UNUSED)
122{
123  tree decl, x;
124  int tok;
125
126  if (c_lex (&x) != CPP_OPEN_PAREN)
127    BAD ("missing '(' after '#pragma unused', ignoring");
128
129  while (1)
130    {
131      tok = c_lex (&decl);
132      if (tok == CPP_NAME && decl)
133	{
134	  tree local = lookup_name (decl);
135	  if (local && (TREE_CODE (local) == PARM_DECL
136			|| TREE_CODE (local) == VAR_DECL))
137	    TREE_USED (local) = 1;
138	  tok = c_lex (&x);
139	  if (tok != CPP_COMMA)
140	    break;
141	}
142    }
143
144  if (tok != CPP_CLOSE_PAREN)
145    BAD ("missing ')' after '#pragma unused', ignoring");
146
147  if (c_lex (&x) != CPP_EOF)
148    warning ("junk at end of '#pragma unused'");
149}
150