1 /* obstack.c - subroutines used implicitly by object stack macros
2
3 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997,
4 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation,
5 Inc.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License along
18 with this program; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20
21 #ifdef HAVE_CONFIG_H
22 # include <config.h>
23 #endif
24
25 #ifdef _LIBC
26 # include <obstack.h>
27 # include <shlib-compat.h>
28 #else
29 # include "obstack.h"
30 #endif
31
32 /* NOTE BEFORE MODIFYING THIS FILE: This version number must be
33 incremented whenever callers compiled using an old obstack.h can no
34 longer properly call the functions in this obstack.c. */
35 #define OBSTACK_INTERFACE_VERSION 1
36
37 /* Comment out all this code if we are using the GNU C Library, and are not
38 actually compiling the library itself, and the installed library
39 supports the same library interface we do. This code is part of the GNU
40 C Library, but also included in many other GNU distributions. Compiling
41 and linking in this code is a waste when using the GNU C library
42 (especially if it is a shared library). Rather than having every GNU
43 program understand `configure --with-gnu-libc' and omit the object
44 files, it is simpler to just do this in the source for each such file. */
45
46 #include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */
47 #if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1
48 # include <gnu-versions.h>
49 # if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION
50 # define ELIDE_CODE
51 # endif
52 #endif
53
54 #include <stddef.h>
55
56 #ifndef ELIDE_CODE
57
58
59 # if HAVE_INTTYPES_H
60 # include <inttypes.h>
61 # endif
62 # if HAVE_STDINT_H || defined _LIBC
63 # include <stdint.h>
64 # endif
65
66 /* Determine default alignment. */
67 union fooround
68 {
69 uintmax_t i;
70 long double d;
71 void *p;
72 };
73 struct fooalign
74 {
75 char c;
76 union fooround u;
77 };
78 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
79 But in fact it might be less smart and round addresses to as much as
80 DEFAULT_ROUNDING. So we prepare for it to do that. */
81 enum
82 {
83 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u),
84 DEFAULT_ROUNDING = sizeof (union fooround)
85 };
86
87 /* When we copy a long block of data, this is the unit to do it with.
88 On some machines, copying successive ints does not work;
89 in such a case, redefine COPYING_UNIT to `long' (if that works)
90 or `char' as a last resort. */
91 # ifndef COPYING_UNIT
92 # define COPYING_UNIT int
93 # endif
94
95
96 /* The functions allocating more room by calling `obstack_chunk_alloc'
97 jump to the handler pointed to by `obstack_alloc_failed_handler'.
98 This can be set to a user defined function which should either
99 abort gracefully or use longjump - but shouldn't return. This
100 variable by default points to the internal function
101 `print_and_abort'. */
102 static void print_and_abort (void);
103 void (*obstack_alloc_failed_handler) (void) = print_and_abort;
104
105 /* Exit value used when `print_and_abort' is used. */
106 # include <stdlib.h>
107 # ifdef _LIBC
108 int obstack_exit_failure = EXIT_FAILURE;
109 # else
110 # include "exitfail.h"
111 # define obstack_exit_failure exit_failure
112 # endif
113
114 # ifdef _LIBC
115 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
116 /* A looong time ago (before 1994, anyway; we're not sure) this global variable
117 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C
118 library still exports it because somebody might use it. */
119 struct obstack *_obstack_compat;
120 compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0);
121 # endif
122 # endif
123
124 /* Define a macro that either calls functions with the traditional malloc/free
125 calling interface, or calls functions with the mmalloc/mfree interface
126 (that adds an extra first argument), based on the state of use_extra_arg.
127 For free, do not use ?:, since some compilers, like the MIPS compilers,
128 do not allow (expr) ? void : void. */
129
130 # define CALL_CHUNKFUN(h, size) \
131 (((h) -> use_extra_arg) \
132 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
133 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
134
135 # define CALL_FREEFUN(h, old_chunk) \
136 do { \
137 if ((h) -> use_extra_arg) \
138 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
139 else \
140 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
141 } while (0)
142
143
144 /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
145 Objects start on multiples of ALIGNMENT (0 means use default).
146 CHUNKFUN is the function to use to allocate chunks,
147 and FREEFUN the function to free them.
148
149 Return nonzero if successful, calls obstack_alloc_failed_handler if
150 allocation fails. */
151
152 int
_obstack_begin(struct obstack * h,int size,int alignment,void * (* chunkfun)(long),void (* freefun)(void *))153 _obstack_begin (struct obstack *h,
154 int size, int alignment,
155 void *(*chunkfun) (long),
156 void (*freefun) (void *))
157 {
158 register struct _obstack_chunk *chunk; /* points to new chunk */
159
160 if (alignment == 0)
161 alignment = DEFAULT_ALIGNMENT;
162 if (size == 0)
163 /* Default size is what GNU malloc can fit in a 4096-byte block. */
164 {
165 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
166 Use the values for range checking, because if range checking is off,
167 the extra bytes won't be missed terribly, but if range checking is on
168 and we used a larger request, a whole extra 4096 bytes would be
169 allocated.
170
171 These number are irrelevant to the new GNU malloc. I suspect it is
172 less sensitive to the size of the request. */
173 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
174 + 4 + DEFAULT_ROUNDING - 1)
175 & ~(DEFAULT_ROUNDING - 1));
176 size = 4096 - extra;
177 }
178
179 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
180 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
181 h->chunk_size = size;
182 h->alignment_mask = alignment - 1;
183 h->use_extra_arg = 0;
184
185 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
186 if (!chunk)
187 (*obstack_alloc_failed_handler) ();
188 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
189 alignment - 1);
190 h->chunk_limit = chunk->limit
191 = (char *) chunk + h->chunk_size;
192 chunk->prev = 0;
193 /* The initial chunk now contains no empty object. */
194 h->maybe_empty_object = 0;
195 h->alloc_failed = 0;
196 return 1;
197 }
198
199 int
_obstack_begin_1(struct obstack * h,int size,int alignment,void * (* chunkfun)(void *,long),void (* freefun)(void *,void *),void * arg)200 _obstack_begin_1 (struct obstack *h, int size, int alignment,
201 void *(*chunkfun) (void *, long),
202 void (*freefun) (void *, void *),
203 void *arg)
204 {
205 register struct _obstack_chunk *chunk; /* points to new chunk */
206
207 if (alignment == 0)
208 alignment = DEFAULT_ALIGNMENT;
209 if (size == 0)
210 /* Default size is what GNU malloc can fit in a 4096-byte block. */
211 {
212 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
213 Use the values for range checking, because if range checking is off,
214 the extra bytes won't be missed terribly, but if range checking is on
215 and we used a larger request, a whole extra 4096 bytes would be
216 allocated.
217
218 These number are irrelevant to the new GNU malloc. I suspect it is
219 less sensitive to the size of the request. */
220 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
221 + 4 + DEFAULT_ROUNDING - 1)
222 & ~(DEFAULT_ROUNDING - 1));
223 size = 4096 - extra;
224 }
225
226 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
227 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
228 h->chunk_size = size;
229 h->alignment_mask = alignment - 1;
230 h->extra_arg = arg;
231 h->use_extra_arg = 1;
232
233 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
234 if (!chunk)
235 (*obstack_alloc_failed_handler) ();
236 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
237 alignment - 1);
238 h->chunk_limit = chunk->limit
239 = (char *) chunk + h->chunk_size;
240 chunk->prev = 0;
241 /* The initial chunk now contains no empty object. */
242 h->maybe_empty_object = 0;
243 h->alloc_failed = 0;
244 return 1;
245 }
246
247 /* Allocate a new current chunk for the obstack *H
248 on the assumption that LENGTH bytes need to be added
249 to the current object, or a new object of length LENGTH allocated.
250 Copies any partial object from the end of the old chunk
251 to the beginning of the new one. */
252
253 void
_obstack_newchunk(struct obstack * h,int length)254 _obstack_newchunk (struct obstack *h, int length)
255 {
256 register struct _obstack_chunk *old_chunk = h->chunk;
257 register struct _obstack_chunk *new_chunk;
258 register long new_size;
259 register long obj_size = h->next_free - h->object_base;
260 register long i;
261 long already;
262 char *object_base;
263
264 /* Compute size for new chunk. */
265 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
266 if (new_size < h->chunk_size)
267 new_size = h->chunk_size;
268
269 /* Allocate and initialize the new chunk. */
270 new_chunk = CALL_CHUNKFUN (h, new_size);
271 if (!new_chunk)
272 (*obstack_alloc_failed_handler) ();
273 h->chunk = new_chunk;
274 new_chunk->prev = old_chunk;
275 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
276
277 /* Compute an aligned object_base in the new chunk */
278 object_base =
279 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask);
280
281 /* Move the existing object to the new chunk.
282 Word at a time is fast and is safe if the object
283 is sufficiently aligned. */
284 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
285 {
286 for (i = obj_size / sizeof (COPYING_UNIT) - 1;
287 i >= 0; i--)
288 ((COPYING_UNIT *)object_base)[i]
289 = ((COPYING_UNIT *)h->object_base)[i];
290 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
291 but that can cross a page boundary on a machine
292 which does not do strict alignment for COPYING_UNITS. */
293 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
294 }
295 else
296 already = 0;
297 /* Copy remaining bytes one by one. */
298 for (i = already; i < obj_size; i++)
299 object_base[i] = h->object_base[i];
300
301 /* If the object just copied was the only data in OLD_CHUNK,
302 free that chunk and remove it from the chain.
303 But not if that chunk might contain an empty object. */
304 if (! h->maybe_empty_object
305 && (h->object_base
306 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents,
307 h->alignment_mask)))
308 {
309 new_chunk->prev = old_chunk->prev;
310 CALL_FREEFUN (h, old_chunk);
311 }
312
313 h->object_base = object_base;
314 h->next_free = h->object_base + obj_size;
315 /* The new chunk certainly contains no empty object yet. */
316 h->maybe_empty_object = 0;
317 }
318 # ifdef _LIBC
319 libc_hidden_def (_obstack_newchunk)
320 # endif
321
322 /* Return nonzero if object OBJ has been allocated from obstack H.
323 This is here for debugging.
324 If you use it in a program, you are probably losing. */
325
326 /* Suppress -Wmissing-prototypes warning. We don't want to declare this in
327 obstack.h because it is just for debugging. */
328 int _obstack_allocated_p (struct obstack *h, void *obj);
329
330 int
_obstack_allocated_p(struct obstack * h,void * obj)331 _obstack_allocated_p (struct obstack *h, void *obj)
332 {
333 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
334 register struct _obstack_chunk *plp; /* point to previous chunk if any */
335
336 lp = (h)->chunk;
337 /* We use >= rather than > since the object cannot be exactly at
338 the beginning of the chunk but might be an empty object exactly
339 at the end of an adjacent chunk. */
340 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
341 {
342 plp = lp->prev;
343 lp = plp;
344 }
345 return lp != 0;
346 }
347
348 /* Free objects in obstack H, including OBJ and everything allocate
349 more recently than OBJ. If OBJ is zero, free everything in H. */
350
351 # undef obstack_free
352
353 void
obstack_free(struct obstack * h,void * obj)354 obstack_free (struct obstack *h, void *obj)
355 {
356 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
357 register struct _obstack_chunk *plp; /* point to previous chunk if any */
358
359 lp = h->chunk;
360 /* We use >= because there cannot be an object at the beginning of a chunk.
361 But there can be an empty object at that address
362 at the end of another chunk. */
363 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
364 {
365 plp = lp->prev;
366 CALL_FREEFUN (h, lp);
367 lp = plp;
368 /* If we switch chunks, we can't tell whether the new current
369 chunk contains an empty object, so assume that it may. */
370 h->maybe_empty_object = 1;
371 }
372 if (lp)
373 {
374 h->object_base = h->next_free = (char *) (obj);
375 h->chunk_limit = lp->limit;
376 h->chunk = lp;
377 }
378 else if (obj != 0)
379 /* obj is not in any of the chunks! */
380 abort ();
381 }
382
383 # ifdef _LIBC
384 /* Older versions of libc used a function _obstack_free intended to be
385 called by non-GCC compilers. */
strong_alias(obstack_free,_obstack_free)386 strong_alias (obstack_free, _obstack_free)
387 # endif
388
389 int
390 _obstack_memory_used (struct obstack *h)
391 {
392 register struct _obstack_chunk* lp;
393 register int nbytes = 0;
394
395 for (lp = h->chunk; lp != 0; lp = lp->prev)
396 {
397 nbytes += lp->limit - (char *) lp;
398 }
399 return nbytes;
400 }
401
402 /* Define the error handler. */
403 # ifdef _LIBC
404 # include <libintl.h>
405 # else
406 # include "gettext.h"
407 # endif
408 # ifndef _
409 # define _(msgid) gettext (msgid)
410 # endif
411
412 # ifdef _LIBC
413 # include <libio/iolibio.h>
414 # endif
415
416 # ifndef __attribute__
417 /* This feature is available in gcc versions 2.5 and later. */
418 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
419 # define __attribute__(Spec) /* empty */
420 # endif
421 # endif
422
423 static void
424 __attribute__ ((noreturn))
print_and_abort(void)425 print_and_abort (void)
426 {
427 /* Don't change any of these strings. Yes, it would be possible to add
428 the newline to the string and use fputs or so. But this must not
429 happen because the "memory exhausted" message appears in other places
430 like this and the translation should be reused instead of creating
431 a very similar string which requires a separate translation. */
432 # ifdef _LIBC
433 (void) __fxprintf (NULL, "%s\n", _("memory exhausted"));
434 # else
435 fprintf (stderr, "%s\n", _("memory exhausted"));
436 # endif
437 exit (obstack_exit_failure);
438 }
439
440 #endif /* !ELIDE_CODE */
441