darwin-c.c revision 90075 
1/* Darwin support needed only by C/C++ frontends.
2   Copyright (C) 2001
3   Free Software Foundation, Inc.
4   Contributed by Apple Computer 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#include "config.h"
24#include "system.h"
25#include "cpplib.h"
26#include "tree.h"
27#include "c-pragma.h"
28#include "c-lex.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 PARAMS ((int));
41static void pop_field_alignment PARAMS ((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 (bit_alignment)
53     int bit_alignment;
54{
55  align_stack *entry = (align_stack *) xmalloc (sizeof (align_stack));
56
57  entry->alignment = maximum_field_alignment;
58  entry->prev = field_align_stack;
59  field_align_stack = entry;
60
61  maximum_field_alignment = bit_alignment;
62}
63
64static void
65pop_field_alignment ()
66{
67  if (field_align_stack)
68    {
69      align_stack *entry = field_align_stack;
70
71      maximum_field_alignment = entry->alignment;
72      field_align_stack = entry->prev;
73      free (entry);
74    }
75  else
76    error ("too many #pragma options align=reset");
77}
78
79/* Handlers for Darwin-specific pragmas.  */
80
81void
82darwin_pragma_ignore (pfile)
83     cpp_reader *pfile ATTRIBUTE_UNUSED;
84{
85  /* Do nothing.  */
86}
87
88/* #pragma options align={mac68k|power|reset} */
89
90void
91darwin_pragma_options (pfile)
92     cpp_reader *pfile ATTRIBUTE_UNUSED;
93{
94  char *arg;
95  tree t, x;
96
97  if (c_lex (&t) != CPP_NAME)
98    BAD ("malformed '#pragma options', ignoring");
99  arg = IDENTIFIER_POINTER (t);
100  if (strcmp (arg, "align"))
101    BAD ("malformed '#pragma options', ignoring");
102  if (c_lex (&t) != CPP_EQ)
103    BAD ("malformed '#pragma options', ignoring");
104  if (c_lex (&t) != CPP_NAME)
105    BAD ("malformed '#pragma options', ignoring");
106
107  if (c_lex (&x) != CPP_EOF)
108    warning ("junk at end of '#pragma options'");
109
110  arg = IDENTIFIER_POINTER (t);
111  if (!strcmp (arg, "mac68k"))
112    push_field_alignment (16);
113  else if (!strcmp (arg, "power"))
114    push_field_alignment (0);
115  else if (!strcmp (arg, "reset"))
116    pop_field_alignment ();
117  else
118    warning ("malformed '#pragma options align={mac68k|power|reset}', ignoring");
119}
120
121/* #pragma unused ([var {, var}*]) */
122
123void
124darwin_pragma_unused (pfile)
125     cpp_reader *pfile ATTRIBUTE_UNUSED;
126{
127  tree decl, x;
128  int tok;
129
130  if (c_lex (&x) != CPP_OPEN_PAREN)
131    BAD ("missing '(' after '#pragma unused', ignoring");
132
133  while (1)
134    {
135      tok = c_lex (&decl);
136      if (tok == CPP_NAME && decl)
137	{
138	  tree local = IDENTIFIER_LOCAL_VALUE (decl);
139	  if (local && (TREE_CODE (local) == PARM_DECL
140			|| TREE_CODE (local) == VAR_DECL))
141	    TREE_USED (local) = 1;
142	  tok = c_lex (&x);
143	  if (tok != CPP_COMMA)
144	    break;
145	}
146    }
147
148  if (tok != CPP_CLOSE_PAREN)
149    BAD ("missing ')' after '#pragma unused', ignoring");
150
151  if (c_lex (&x) != CPP_EOF)
152    warning ("junk at end of '#pragma unused'");
153}
154