1 /* Handle #pragma, system V.4 style. Supports #pragma weak and #pragma pack.
2 Copyright (C) 1992, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
36 extern cpp_reader parse_in;
39 static struct pragma_entry *pragmas;
41 void cpp_register_pragma PARAMS ((cpp_reader *, const char *, const char *,
42 void (*) PARAMS ((cpp_reader *)) ));
43 void cpp_register_pragma_space PARAMS ((cpp_reader *, const char *));
46 #define BAD(msgid) do { warning (msgid); return; } while (0)
47 #define BAD2(msgid, arg) do { warning (msgid, arg); return; } while (0)
49 #ifdef HANDLE_PRAGMA_PACK
50 static void handle_pragma_pack PARAMS ((cpp_reader *));
52 #ifdef HANDLE_PRAGMA_PACK_PUSH_POP
53 typedef struct align_stack
56 unsigned int num_pushes;
58 struct align_stack * prev;
61 static struct align_stack * alignment_stack = NULL;
63 /* If we have a "global" #pragma pack(<n>) in effect when the first
64 #pragma pack(push,<n>) is encountered, this stores the value of
65 maximum_field_alignment in effect. When the final pop_alignment()
66 happens, we restore the value to this, not to a value of 0 for
67 maximum_field_alignment. Value is in bits. */
68 static int default_alignment;
69 #define SET_GLOBAL_ALIGNMENT(ALIGN) \
70 (default_alignment = maximum_field_alignment = (ALIGN))
72 static void push_alignment PARAMS ((int, tree));
73 static void pop_alignment PARAMS ((tree));
74 static void mark_align_stack PARAMS ((void *));
76 /* Push an alignment value onto the stack. */
78 push_alignment (alignment, id)
83 if (alignment_stack == NULL
84 || alignment_stack->alignment != alignment
89 entry = (align_stack *) xmalloc (sizeof (* entry));
91 entry->alignment = alignment;
92 entry->num_pushes = 1;
94 entry->prev = alignment_stack;
96 /* The current value of maximum_field_alignment is not necessarily
97 0 since there may be a #pragma pack(<n>) in effect; remember it
98 so that we can restore it after the final #pragma pop(). */
99 if (alignment_stack == NULL)
100 default_alignment = maximum_field_alignment;
102 alignment_stack = entry;
104 maximum_field_alignment = alignment;
107 alignment_stack->num_pushes ++;
110 /* Undo a push of an alignment onto the stack. */
117 if (alignment_stack == NULL)
120 #pragma pack (pop) encountered without matching #pragma pack (push, <n>)"
125 /* If we got an identifier, strip away everything above the target
126 entry so that the next step will restore the state just below it. */
129 for (entry = alignment_stack; entry; entry = entry->prev)
132 entry->num_pushes = 1;
133 alignment_stack = entry;
138 #pragma pack(pop, %s) encountered without matching #pragma pack(push, %s, <n>)"
139 , IDENTIFIER_POINTER (id), IDENTIFIER_POINTER (id));
142 if (-- alignment_stack->num_pushes == 0)
144 entry = alignment_stack->prev;
147 maximum_field_alignment = default_alignment;
149 maximum_field_alignment = entry->alignment;
151 free (alignment_stack);
153 alignment_stack = entry;
161 align_stack *a = *(align_stack **) p;
165 ggc_mark_tree (a->id);
169 #else /* not HANDLE_PRAGMA_PACK_PUSH_POP */
170 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = (ALIGN))
171 #define push_alignment(ID, N) \
172 BAD("#pragma pack(push[, id], <n>) is not supported on this target")
173 #define pop_alignment(ID) \
174 BAD("#pragma pack(pop[, id], <n>) is not supported on this target")
175 #endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
180 #pragma pack (push, N)
181 #pragma pack (push, ID, N)
183 #pragma pack (pop, ID) */
185 handle_pragma_pack (dummy)
186 cpp_reader *dummy ATTRIBUTE_UNUSED;
190 enum cpp_ttype token;
191 enum { set, push, pop } action;
193 if (c_lex (&x) != CPP_OPEN_PAREN)
194 BAD ("missing '(' after '#pragma pack' - ignored");
197 if (token == CPP_CLOSE_PAREN)
202 else if (token == CPP_NUMBER)
204 align = TREE_INT_CST_LOW (x);
206 if (c_lex (&x) != CPP_CLOSE_PAREN)
207 BAD ("malformed '#pragma pack' - ignored");
209 else if (token == CPP_NAME)
211 #define BAD_ACTION do { if (action == push) \
212 BAD ("malformed '#pragma pack(push[, id], <n>)' - ignored"); \
214 BAD ("malformed '#pragma pack(pop[, id])' - ignored"); \
217 const char *op = IDENTIFIER_POINTER (x);
218 if (!strcmp (op, "push"))
220 else if (!strcmp (op, "pop"))
223 BAD2 ("unknown action '%s' for '#pragma pack' - ignored", op);
226 if (token != CPP_COMMA && action == push)
229 if (token == CPP_COMMA)
232 if (token == CPP_NAME)
235 if (action == push && c_lex (&x) != CPP_COMMA)
242 if (token == CPP_NUMBER)
244 align = TREE_INT_CST_LOW (x);
252 if (token != CPP_CLOSE_PAREN)
257 BAD ("malformed '#pragma pack' - ignored");
259 if (c_lex (&x) != CPP_EOF)
260 warning ("junk at end of '#pragma pack'");
271 align *= BITS_PER_UNIT;
274 BAD2 ("alignment must be a small power of two, not %d", align);
279 case set: SET_GLOBAL_ALIGNMENT (align); break;
280 case push: push_alignment (align, id); break;
281 case pop: pop_alignment (id); break;
284 #endif /* HANDLE_PRAGMA_PACK */
286 #ifdef HANDLE_PRAGMA_WEAK
287 static void handle_pragma_weak PARAMS ((cpp_reader *));
289 /* #pragma weak name [= value] */
291 handle_pragma_weak (dummy)
292 cpp_reader *dummy ATTRIBUTE_UNUSED;
299 if (c_lex (&name) != CPP_NAME)
300 BAD ("malformed #pragma weak, ignored");
304 if (c_lex (&value) != CPP_NAME)
305 BAD ("malformed #pragma weak, ignored");
309 warning ("junk at end of #pragma weak");
311 add_weak (IDENTIFIER_POINTER (name), value ? IDENTIFIER_POINTER (value) : 0);
316 /* Glue version of cpplib's pragma registration and dispatch system. */
319 struct pragma_entry *next;
324 void (*handler) PARAMS ((cpp_reader *));
325 struct pragma_entry *space;
330 cpp_register_pragma_space (pfile, space)
331 cpp_reader *pfile ATTRIBUTE_UNUSED;
334 struct pragma_entry *new;
335 const struct pragma_entry *p = pragmas;
336 size_t len = strlen (space);
340 if (p->isnspace && p->len == len && !memcmp (p->name, space, len))
345 new = (struct pragma_entry *) xmalloc (sizeof (struct pragma_entry));
356 cpp_register_pragma (pfile, space, name, handler)
357 cpp_reader *pfile ATTRIBUTE_UNUSED;
360 void (*handler) PARAMS ((cpp_reader *));
362 struct pragma_entry **x, *new;
368 struct pragma_entry *p = pragmas;
369 len = strlen (space);
372 if (p->isnspace && p->len == len && !memcmp (p->name, space, len))
383 new = (struct pragma_entry *) xmalloc (sizeof (struct pragma_entry));
385 new->len = strlen (name);
387 new->u.handler = handler;
393 /* Called from process_directive() for #pragma lines. */
399 const struct pragma_entry *p;
400 const char *name, *space = 0;
412 warning ("malformed #pragma directive");
416 name = IDENTIFIER_POINTER (x);
417 len = IDENTIFIER_LENGTH (x);
420 if (strlen (p->name) == len && !memcmp (p->name, name, len))
437 /* Issue a warning message if we have been asked to do so. Ignore
438 unknown pragmas in system headers unless an explicit
439 -Wunknown-pragmas has been given. */
440 if (warn_unknown_pragmas > in_system_header)
443 warning ("ignoring #pragma %s %s", space, name);
445 warning ("ignoring #pragma %s", name);
454 cpp_reader *pfile ATTRIBUTE_UNUSED;
461 #ifdef HANDLE_PRAGMA_PACK
462 cpp_register_pragma (pfile, 0, "pack", handle_pragma_pack);
464 #ifdef HANDLE_PRAGMA_WEAK
465 cpp_register_pragma (pfile, 0, "weak", handle_pragma_weak);
467 #ifdef REGISTER_TARGET_PRAGMAS
468 REGISTER_TARGET_PRAGMAS (pfile);
471 #ifdef HANDLE_PRAGMA_PACK_PUSH_POP
472 ggc_add_root (&alignment_stack, 1, sizeof(alignment_stack),