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, 2006 Free Software
5 Foundation, 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 _LIBC
22 # include <obstack.h>
23 # include <shlib-compat.h>
24 #else
25 # include <config.h>
26 # include "obstack.h"
27 #endif
28
29 /* NOTE BEFORE MODIFYING THIS FILE: This version number must be
30 incremented whenever callers compiled using an old obstack.h can no
31 longer properly call the functions in this obstack.c. */
32 #define OBSTACK_INTERFACE_VERSION 1
33
34 /* Comment out all this code if we are using the GNU C Library, and are not
35 actually compiling the library itself, and the installed library
36 supports the same library interface we do. This code is part of the GNU
37 C Library, but also included in many other GNU distributions. Compiling
38 and linking in this code is a waste when using the GNU C library
39 (especially if it is a shared library). Rather than having every GNU
40 program understand `configure --with-gnu-libc' and omit the object
41 files, it is simpler to just do this in the source for each such file. */
42
43 #include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */
44 #if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1
45 # include <gnu-versions.h>
46 # if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION
47 # define ELIDE_CODE
48 # endif
49 #endif
50
51 #include <stddef.h>
52
53 #ifndef ELIDE_CODE
54
55 # include <stdint.h>
56
57 /* Determine default alignment. */
58 union fooround
59 {
60 uintmax_t i;
61 long double d;
62 void *p;
63 };
64 struct fooalign
65 {
66 char c;
67 union fooround u;
68 };
69 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
70 But in fact it might be less smart and round addresses to as much as
71 DEFAULT_ROUNDING. So we prepare for it to do that. */
72 enum
73 {
74 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u),
75 DEFAULT_ROUNDING = sizeof (union fooround)
76 };
77
78 /* When we copy a long block of data, this is the unit to do it with.
79 On some machines, copying successive ints does not work;
80 in such a case, redefine COPYING_UNIT to `long' (if that works)
81 or `char' as a last resort. */
82 # ifndef COPYING_UNIT
83 # define COPYING_UNIT int
84 # endif
85
86
87 /* The functions allocating more room by calling `obstack_chunk_alloc'
88 jump to the handler pointed to by `obstack_alloc_failed_handler'.
89 This can be set to a user defined function which should either
90 abort gracefully or use longjmp - but shouldn't return. This
91 variable by default points to the internal function
92 `print_and_abort'. */
93 static void print_and_abort (void);
94 void (*obstack_alloc_failed_handler) (void) = print_and_abort;
95
96 /* Exit value used when `print_and_abort' is used. */
97 # include <stdlib.h>
98 # ifdef _LIBC
99 int obstack_exit_failure = EXIT_FAILURE;
100 # else
101 #ifndef EXIT_FAILURE
102 #define EXIT_FAILURE 1
103 #endif
104 int volatile exit_failure = EXIT_FAILURE;
105 # define obstack_exit_failure exit_failure
106 # endif
107
108 # ifdef _LIBC
109 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
110 /* A looong time ago (before 1994, anyway; we're not sure) this global variable
111 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C
112 library still exports it because somebody might use it. */
113 struct obstack *_obstack_compat;
114 compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0);
115 # endif
116 # endif
117
118 /* Define a macro that either calls functions with the traditional malloc/free
119 calling interface, or calls functions with the mmalloc/mfree interface
120 (that adds an extra first argument), based on the state of use_extra_arg.
121 For free, do not use ?:, since some compilers, like the MIPS compilers,
122 do not allow (expr) ? void : void. */
123
124 # define CALL_CHUNKFUN(h, size) \
125 (((h) -> use_extra_arg) \
126 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
127 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
128
129 # define CALL_FREEFUN(h, old_chunk) \
130 do { \
131 if ((h) -> use_extra_arg) \
132 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
133 else \
134 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
135 } while (0)
136
137
138 /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
139 Objects start on multiples of ALIGNMENT (0 means use default).
140 CHUNKFUN is the function to use to allocate chunks,
141 and FREEFUN the function to free them.
142
143 Return nonzero if successful, calls obstack_alloc_failed_handler if
144 allocation fails. */
145
146 int
_obstack_begin(struct obstack * h,int size,int alignment,void * (* chunkfun)(long),void (* freefun)(void *))147 _obstack_begin (struct obstack *h,
148 int size, int alignment,
149 void *(*chunkfun) (long),
150 void (*freefun) (void *))
151 {
152 register struct _obstack_chunk *chunk; /* points to new chunk */
153
154 if (alignment == 0)
155 alignment = DEFAULT_ALIGNMENT;
156 if (size == 0)
157 /* Default size is what GNU malloc can fit in a 4096-byte block. */
158 {
159 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
160 Use the values for range checking, because if range checking is off,
161 the extra bytes won't be missed terribly, but if range checking is on
162 and we used a larger request, a whole extra 4096 bytes would be
163 allocated.
164
165 These number are irrelevant to the new GNU malloc. I suspect it is
166 less sensitive to the size of the request. */
167 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
168 + 4 + DEFAULT_ROUNDING - 1)
169 & ~(DEFAULT_ROUNDING - 1));
170 size = 4096 - extra;
171 }
172
173 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
174 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
175 h->chunk_size = size;
176 h->alignment_mask = alignment - 1;
177 h->use_extra_arg = 0;
178
179 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
180 if (!chunk)
181 (*obstack_alloc_failed_handler) ();
182 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
183 alignment - 1);
184 h->chunk_limit = chunk->limit
185 = (char *) chunk + h->chunk_size;
186 chunk->prev = 0;
187 /* The initial chunk now contains no empty object. */
188 h->maybe_empty_object = 0;
189 h->alloc_failed = 0;
190 return 1;
191 }
192
193 int
_obstack_begin_1(struct obstack * h,int size,int alignment,void * (* chunkfun)(void *,long),void (* freefun)(void *,void *),void * arg)194 _obstack_begin_1 (struct obstack *h, int size, int alignment,
195 void *(*chunkfun) (void *, long),
196 void (*freefun) (void *, void *),
197 void *arg)
198 {
199 register struct _obstack_chunk *chunk; /* points to new chunk */
200
201 if (alignment == 0)
202 alignment = DEFAULT_ALIGNMENT;
203 if (size == 0)
204 /* Default size is what GNU malloc can fit in a 4096-byte block. */
205 {
206 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
207 Use the values for range checking, because if range checking is off,
208 the extra bytes won't be missed terribly, but if range checking is on
209 and we used a larger request, a whole extra 4096 bytes would be
210 allocated.
211
212 These number are irrelevant to the new GNU malloc. I suspect it is
213 less sensitive to the size of the request. */
214 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
215 + 4 + DEFAULT_ROUNDING - 1)
216 & ~(DEFAULT_ROUNDING - 1));
217 size = 4096 - extra;
218 }
219
220 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
221 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
222 h->chunk_size = size;
223 h->alignment_mask = alignment - 1;
224 h->extra_arg = arg;
225 h->use_extra_arg = 1;
226
227 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
228 if (!chunk)
229 (*obstack_alloc_failed_handler) ();
230 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
231 alignment - 1);
232 h->chunk_limit = chunk->limit
233 = (char *) chunk + h->chunk_size;
234 chunk->prev = 0;
235 /* The initial chunk now contains no empty object. */
236 h->maybe_empty_object = 0;
237 h->alloc_failed = 0;
238 return 1;
239 }
240
241 /* Allocate a new current chunk for the obstack *H
242 on the assumption that LENGTH bytes need to be added
243 to the current object, or a new object of length LENGTH allocated.
244 Copies any partial object from the end of the old chunk
245 to the beginning of the new one. */
246
247 void
_obstack_newchunk(struct obstack * h,int length)248 _obstack_newchunk (struct obstack *h, int length)
249 {
250 register struct _obstack_chunk *old_chunk = h->chunk;
251 register struct _obstack_chunk *new_chunk;
252 register long new_size;
253 register long obj_size = h->next_free - h->object_base;
254 register long i;
255 long already;
256 char *object_base;
257
258 /* Compute size for new chunk. */
259 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
260 if (new_size < h->chunk_size)
261 new_size = h->chunk_size;
262
263 /* Allocate and initialize the new chunk. */
264 new_chunk = CALL_CHUNKFUN (h, new_size);
265 if (!new_chunk)
266 (*obstack_alloc_failed_handler) ();
267 h->chunk = new_chunk;
268 new_chunk->prev = old_chunk;
269 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
270
271 /* Compute an aligned object_base in the new chunk */
272 object_base =
273 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask);
274
275 /* Move the existing object to the new chunk.
276 Word at a time is fast and is safe if the object
277 is sufficiently aligned. */
278 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
279 {
280 for (i = obj_size / sizeof (COPYING_UNIT) - 1;
281 i >= 0; i--)
282 ((COPYING_UNIT *)object_base)[i]
283 = ((COPYING_UNIT *)h->object_base)[i];
284 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
285 but that can cross a page boundary on a machine
286 which does not do strict alignment for COPYING_UNITS. */
287 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
288 }
289 else
290 already = 0;
291 /* Copy remaining bytes one by one. */
292 for (i = already; i < obj_size; i++)
293 object_base[i] = h->object_base[i];
294
295 /* If the object just copied was the only data in OLD_CHUNK,
296 free that chunk and remove it from the chain.
297 But not if that chunk might contain an empty object. */
298 if (! h->maybe_empty_object
299 && (h->object_base
300 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents,
301 h->alignment_mask)))
302 {
303 new_chunk->prev = old_chunk->prev;
304 CALL_FREEFUN (h, old_chunk);
305 }
306
307 h->object_base = object_base;
308 h->next_free = h->object_base + obj_size;
309 /* The new chunk certainly contains no empty object yet. */
310 h->maybe_empty_object = 0;
311 }
312 # ifdef _LIBC
313 libc_hidden_def (_obstack_newchunk)
314 # endif
315
316 /* Return nonzero if object OBJ has been allocated from obstack H.
317 This is here for debugging.
318 If you use it in a program, you are probably losing. */
319
320 /* Suppress -Wmissing-prototypes warning. We don't want to declare this in
321 obstack.h because it is just for debugging. */
322 int _obstack_allocated_p (struct obstack *h, void *obj);
323
324 int
_obstack_allocated_p(struct obstack * h,void * obj)325 _obstack_allocated_p (struct obstack *h, void *obj)
326 {
327 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
328 register struct _obstack_chunk *plp; /* point to previous chunk if any */
329
330 lp = (h)->chunk;
331 /* We use >= rather than > since the object cannot be exactly at
332 the beginning of the chunk but might be an empty object exactly
333 at the end of an adjacent chunk. */
334 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
335 {
336 plp = lp->prev;
337 lp = plp;
338 }
339 return lp != 0;
340 }
341
342 /* Free objects in obstack H, including OBJ and everything allocate
343 more recently than OBJ. If OBJ is zero, free everything in H. */
344
345 # undef obstack_free
346
347 void
__obstack_free(struct obstack * h,void * obj)348 __obstack_free (struct obstack *h, void *obj)
349 {
350 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
351 register struct _obstack_chunk *plp; /* point to previous chunk if any */
352
353 lp = h->chunk;
354 /* We use >= because there cannot be an object at the beginning of a chunk.
355 But there can be an empty object at that address
356 at the end of another chunk. */
357 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
358 {
359 plp = lp->prev;
360 CALL_FREEFUN (h, lp);
361 lp = plp;
362 /* If we switch chunks, we can't tell whether the new current
363 chunk contains an empty object, so assume that it may. */
364 h->maybe_empty_object = 1;
365 }
366 if (lp)
367 {
368 h->object_base = h->next_free = (char *) (obj);
369 h->chunk_limit = lp->limit;
370 h->chunk = lp;
371 }
372 else if (obj != 0)
373 /* obj is not in any of the chunks! */
374 abort ();
375 }
376
377 # ifdef _LIBC
378 /* Older versions of libc used a function _obstack_free intended to be
379 called by non-GCC compilers. */
strong_alias(obstack_free,_obstack_free)380 strong_alias (obstack_free, _obstack_free)
381 # endif
382
383 int
384 _obstack_memory_used (struct obstack *h)
385 {
386 register struct _obstack_chunk* lp;
387 register int nbytes = 0;
388
389 for (lp = h->chunk; lp != 0; lp = lp->prev)
390 {
391 nbytes += lp->limit - (char *) lp;
392 }
393 return nbytes;
394 }
395
396 /* Define the error handler. */
397 # ifdef _LIBC
398 # include <libintl.h>
399 # else
400 # include "gettext.h"
401 # endif
402 # ifndef _
403 # define _(msgid) gettext (msgid)
404 # endif
405
406 # ifdef _LIBC
407 # include <libio/iolibio.h>
408 # endif
409
410 # ifndef __attribute__
411 /* This feature is available in gcc versions 2.5 and later. */
412 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
413 # define __attribute__(Spec) /* empty */
414 # endif
415 # endif
416
417 static void
418 __attribute__ ((noreturn))
print_and_abort(void)419 print_and_abort (void)
420 {
421 /* Don't change any of these strings. Yes, it would be possible to add
422 the newline to the string and use fputs or so. But this must not
423 happen because the "memory exhausted" message appears in other places
424 like this and the translation should be reused instead of creating
425 a very similar string which requires a separate translation. */
426 # ifdef _LIBC
427 (void) __fxprintf (NULL, "%s\n", _("memory exhausted"));
428 # else
429 fprintf (stderr, "%s\n", _("memory exhausted"));
430 # endif
431 exit (obstack_exit_failure);
432 }
433
434 #endif /* !ELIDE_CODE */
435