source: trunk/grep/lib/obstack.c@ 2787

Last change on this file since 2787 was 2557, checked in by bird, 19 years ago

grep 2.5.1a

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1/* obstack.c - subroutines used implicitly by object stack macros
2 Copyright (C) 1988-1994,96,97,98,99 Free Software Foundation, Inc.
3
4 This file is part of the GNU C Library. Its master source is NOT part of
5 the C library, however. The master source lives in /gd/gnu/lib.
6
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public License as
9 published by the Free Software Foundation; either version 2 of the
10 License, or (at your option) any later version.
11
12 The GNU C Library 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 GNU
15 Library General Public License for more details.
16
17 You should have received a copy of the GNU Library General Public
18 License along with the GNU C Library; see the file COPYING.LIB. If not,
19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
21
22#ifdef HAVE_CONFIG_H
23#include <config.h>
24#endif
25
26#include "obstack.h"
27
28/* NOTE BEFORE MODIFYING THIS FILE: This version number must be
29 incremented whenever callers compiled using an old obstack.h can no
30 longer properly call the functions in this obstack.c. */
31#define OBSTACK_INTERFACE_VERSION 1
32
33/* Comment out all this code if we are using the GNU C Library, and are not
34 actually compiling the library itself, and the installed library
35 supports the same library interface we do. This code is part of the GNU
36 C Library, but also included in many other GNU distributions. Compiling
37 and linking in this code is a waste when using the GNU C library
38 (especially if it is a shared library). Rather than having every GNU
39 program understand `configure --with-gnu-libc' and omit the object
40 files, it is simpler to just do this in the source for each such file. */
41
42#include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */
43#if !defined (_LIBC) && defined (__GNU_LIBRARY__) && __GNU_LIBRARY__ > 1
44#include <gnu-versions.h>
45#if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION
46#define ELIDE_CODE
47#endif
48#endif
49
50
51#ifndef ELIDE_CODE
52
53
54#if defined (__STDC__) && __STDC__
55#define POINTER void *
56#else
57#define POINTER char *
58#endif
59
60/* Determine default alignment. */
61struct fooalign {char x; double d;};
62#define DEFAULT_ALIGNMENT \
63 ((PTR_INT_TYPE) ((char *) &((struct fooalign *) 0)->d - (char *) 0))
64/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
65 But in fact it might be less smart and round addresses to as much as
66 DEFAULT_ROUNDING. So we prepare for it to do that. */
67union fooround {long x; double d;};
68#define DEFAULT_ROUNDING (sizeof (union fooround))
69
70/* When we copy a long block of data, this is the unit to do it with.
71 On some machines, copying successive ints does not work;
72 in such a case, redefine COPYING_UNIT to `long' (if that works)
73 or `char' as a last resort. */
74#ifndef COPYING_UNIT
75#define COPYING_UNIT int
76#endif
77
78
79/* The functions allocating more room by calling `obstack_chunk_alloc'
80 jump to the handler pointed to by `obstack_alloc_failed_handler'.
81 This can be set to a user defined function which should either
82 abort gracefully or use longjump - but shouldn't return. This
83 variable by default points to the internal function
84 `print_and_abort'. */
85#if defined (__STDC__) && __STDC__
86static void print_and_abort (void);
87void (*obstack_alloc_failed_handler) (void) = print_and_abort;
88#else
89static void print_and_abort ();
90void (*obstack_alloc_failed_handler) () = print_and_abort;
91#endif
92
93/* Exit value used when `print_and_abort' is used. */
94#if defined __GNU_LIBRARY__ || defined HAVE_STDLIB_H
95#include <stdlib.h>
96#endif
97#ifndef EXIT_FAILURE
98#define EXIT_FAILURE 1
99#endif
100int obstack_exit_failure = EXIT_FAILURE;
101
102/* The non-GNU-C macros copy the obstack into this global variable
103 to avoid multiple evaluation. */
104
105struct obstack *_obstack;
106
107/* Define a macro that either calls functions with the traditional malloc/free
108 calling interface, or calls functions with the mmalloc/mfree interface
109 (that adds an extra first argument), based on the state of use_extra_arg.
110 For free, do not use ?:, since some compilers, like the MIPS compilers,
111 do not allow (expr) ? void : void. */
112
113#if defined (__STDC__) && __STDC__
114#define CALL_CHUNKFUN(h, size) \
115 (((h) -> use_extra_arg) \
116 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
117 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
118
119#define CALL_FREEFUN(h, old_chunk) \
120 do { \
121 if ((h) -> use_extra_arg) \
122 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
123 else \
124 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
125 } while (0)
126#else
127#define CALL_CHUNKFUN(h, size) \
128 (((h) -> use_extra_arg) \
129 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
130 : (*(struct _obstack_chunk *(*) ()) (h)->chunkfun) ((size)))
131
132#define CALL_FREEFUN(h, old_chunk) \
133 do { \
134 if ((h) -> use_extra_arg) \
135 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
136 else \
137 (*(void (*) ()) (h)->freefun) ((old_chunk)); \
138 } while (0)
139#endif
140
141
142
143/* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
144 Objects start on multiples of ALIGNMENT (0 means use default).
145 CHUNKFUN is the function to use to allocate chunks,
146 and FREEFUN the function to free them.
147
148 Return nonzero if successful, calls obstack_alloc_failed_handler if
149 allocation fails. */
150
151int
152_obstack_begin (h, size, alignment, chunkfun, freefun)
153 struct obstack *h;
154 int size;
155 int alignment;
156#if defined (__STDC__) && __STDC__
157 POINTER (*chunkfun) (long);
158 void (*freefun) (void *);
159#else
160 POINTER (*chunkfun) ();
161 void (*freefun) ();
162#endif
163{
164 register struct _obstack_chunk *chunk; /* points to new chunk */
165
166 if (alignment == 0)
167 alignment = (int) DEFAULT_ALIGNMENT;
168 if (size == 0)
169 /* Default size is what GNU malloc can fit in a 4096-byte block. */
170 {
171 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
172 Use the values for range checking, because if range checking is off,
173 the extra bytes won't be missed terribly, but if range checking is on
174 and we used a larger request, a whole extra 4096 bytes would be
175 allocated.
176
177 These number are irrelevant to the new GNU malloc. I suspect it is
178 less sensitive to the size of the request. */
179 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
180 + 4 + DEFAULT_ROUNDING - 1)
181 & ~(DEFAULT_ROUNDING - 1));
182 size = 4096 - extra;
183 }
184
185#if defined (__STDC__) && __STDC__
186 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
187 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
188#else
189 h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
190 h->freefun = freefun;
191#endif
192 h->chunk_size = size;
193 h->alignment_mask = alignment - 1;
194 h->use_extra_arg = 0;
195
196 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
197 if (!chunk)
198 (*obstack_alloc_failed_handler) ();
199 h->next_free = h->object_base = chunk->contents;
200 h->chunk_limit = chunk->limit
201 = (char *) chunk + h->chunk_size;
202 chunk->prev = 0;
203 /* The initial chunk now contains no empty object. */
204 h->maybe_empty_object = 0;
205 h->alloc_failed = 0;
206 return 1;
207}
208
209int
210_obstack_begin_1 (h, size, alignment, chunkfun, freefun, arg)
211 struct obstack *h;
212 int size;
213 int alignment;
214#if defined (__STDC__) && __STDC__
215 POINTER (*chunkfun) (POINTER, long);
216 void (*freefun) (POINTER, POINTER);
217#else
218 POINTER (*chunkfun) ();
219 void (*freefun) ();
220#endif
221 POINTER arg;
222{
223 register struct _obstack_chunk *chunk; /* points to new chunk */
224
225 if (alignment == 0)
226 alignment = (int) DEFAULT_ALIGNMENT;
227 if (size == 0)
228 /* Default size is what GNU malloc can fit in a 4096-byte block. */
229 {
230 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
231 Use the values for range checking, because if range checking is off,
232 the extra bytes won't be missed terribly, but if range checking is on
233 and we used a larger request, a whole extra 4096 bytes would be
234 allocated.
235
236 These number are irrelevant to the new GNU malloc. I suspect it is
237 less sensitive to the size of the request. */
238 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
239 + 4 + DEFAULT_ROUNDING - 1)
240 & ~(DEFAULT_ROUNDING - 1));
241 size = 4096 - extra;
242 }
243
244#if defined(__STDC__) && __STDC__
245 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
246 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
247#else
248 h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
249 h->freefun = freefun;
250#endif
251 h->chunk_size = size;
252 h->alignment_mask = alignment - 1;
253 h->extra_arg = arg;
254 h->use_extra_arg = 1;
255
256 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
257 if (!chunk)
258 (*obstack_alloc_failed_handler) ();
259 h->next_free = h->object_base = chunk->contents;
260 h->chunk_limit = chunk->limit
261 = (char *) chunk + h->chunk_size;
262 chunk->prev = 0;
263 /* The initial chunk now contains no empty object. */
264 h->maybe_empty_object = 0;
265 h->alloc_failed = 0;
266 return 1;
267}
268
269/* Allocate a new current chunk for the obstack *H
270 on the assumption that LENGTH bytes need to be added
271 to the current object, or a new object of length LENGTH allocated.
272 Copies any partial object from the end of the old chunk
273 to the beginning of the new one. */
274
275void
276_obstack_newchunk (h, length)
277 struct obstack *h;
278 int length;
279{
280 register struct _obstack_chunk *old_chunk = h->chunk;
281 register struct _obstack_chunk *new_chunk;
282 register long new_size;
283 register long obj_size = h->next_free - h->object_base;
284 register long i;
285 long already;
286
287 /* Compute size for new chunk. */
288 new_size = (obj_size + length) + (obj_size >> 3) + 100;
289 if (new_size < h->chunk_size)
290 new_size = h->chunk_size;
291
292 /* Allocate and initialize the new chunk. */
293 new_chunk = CALL_CHUNKFUN (h, new_size);
294 if (!new_chunk)
295 (*obstack_alloc_failed_handler) ();
296 h->chunk = new_chunk;
297 new_chunk->prev = old_chunk;
298 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
299
300 /* Move the existing object to the new chunk.
301 Word at a time is fast and is safe if the object
302 is sufficiently aligned. */
303 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
304 {
305 for (i = obj_size / sizeof (COPYING_UNIT) - 1;
306 i >= 0; i--)
307 ((COPYING_UNIT *)new_chunk->contents)[i]
308 = ((COPYING_UNIT *)h->object_base)[i];
309 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
310 but that can cross a page boundary on a machine
311 which does not do strict alignment for COPYING_UNITS. */
312 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
313 }
314 else
315 already = 0;
316 /* Copy remaining bytes one by one. */
317 for (i = already; i < obj_size; i++)
318 new_chunk->contents[i] = h->object_base[i];
319
320 /* If the object just copied was the only data in OLD_CHUNK,
321 free that chunk and remove it from the chain.
322 But not if that chunk might contain an empty object. */
323 if (h->object_base == old_chunk->contents && ! h->maybe_empty_object)
324 {
325 new_chunk->prev = old_chunk->prev;
326 CALL_FREEFUN (h, old_chunk);
327 }
328
329 h->object_base = new_chunk->contents;
330 h->next_free = h->object_base + obj_size;
331 /* The new chunk certainly contains no empty object yet. */
332 h->maybe_empty_object = 0;
333}
334
335/* Return nonzero if object OBJ has been allocated from obstack H.
336 This is here for debugging.
337 If you use it in a program, you are probably losing. */
338
339#if defined (__STDC__) && __STDC__
340/* Suppress -Wmissing-prototypes warning. We don't want to declare this in
341 obstack.h because it is just for debugging. */
342int _obstack_allocated_p (struct obstack *h, POINTER obj);
343#endif
344
345int
346_obstack_allocated_p (h, obj)
347 struct obstack *h;
348 POINTER 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 >= rather than > since the object cannot be exactly at
355 the beginning of the chunk but might be an empty object exactly
356 at the end of an adjacent chunk. */
357 while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
358 {
359 plp = lp->prev;
360 lp = plp;
361 }
362 return lp != 0;
363}
364
365
366/* Free objects in obstack H, including OBJ and everything allocate
367 more recently than OBJ. If OBJ is zero, free everything in H. */
368
369#undef obstack_free
370
371/* This function has two names with identical definitions.
372 This is the first one, called from non-ANSI code. */
373
374void
375_obstack_free (h, obj)
376 struct obstack *h;
377 POINTER obj;
378{
379 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
380 register struct _obstack_chunk *plp; /* point to previous chunk if any */
381
382 lp = h->chunk;
383 /* We use >= because there cannot be an object at the beginning of a chunk.
384 But there can be an empty object at that address
385 at the end of another chunk. */
386 while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
387 {
388 plp = lp->prev;
389 CALL_FREEFUN (h, lp);
390 lp = plp;
391 /* If we switch chunks, we can't tell whether the new current
392 chunk contains an empty object, so assume that it may. */
393 h->maybe_empty_object = 1;
394 }
395 if (lp)
396 {
397 h->object_base = h->next_free = (char *) (obj);
398 h->chunk_limit = lp->limit;
399 h->chunk = lp;
400 }
401 else if (obj != 0)
402 /* obj is not in any of the chunks! */
403 abort ();
404}
405
406/* This function is used from ANSI code. */
407
408void
409obstack_free (h, obj)
410 struct obstack *h;
411 POINTER obj;
412{
413 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
414 register struct _obstack_chunk *plp; /* point to previous chunk if any */
415
416 lp = h->chunk;
417 /* We use >= because there cannot be an object at the beginning of a chunk.
418 But there can be an empty object at that address
419 at the end of another chunk. */
420 while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
421 {
422 plp = lp->prev;
423 CALL_FREEFUN (h, lp);
424 lp = plp;
425 /* If we switch chunks, we can't tell whether the new current
426 chunk contains an empty object, so assume that it may. */
427 h->maybe_empty_object = 1;
428 }
429 if (lp)
430 {
431 h->object_base = h->next_free = (char *) (obj);
432 h->chunk_limit = lp->limit;
433 h->chunk = lp;
434 }
435 else if (obj != 0)
436 /* obj is not in any of the chunks! */
437 abort ();
438}
439
440
441int
442_obstack_memory_used (h)
443 struct obstack *h;
444{
445 register struct _obstack_chunk* lp;
446 register int nbytes = 0;
447
448 for (lp = h->chunk; lp != 0; lp = lp->prev)
449 {
450 nbytes += lp->limit - (char *) lp;
451 }
452 return nbytes;
453}
454
455
456/* Define the error handler. */
457#ifndef _
458# ifdef HAVE_LIBINTL_H
459# include <libintl.h>
460# ifndef _
461# define _(Str) gettext (Str)
462# endif
463# else
464# define _(Str) (Str)
465# endif
466#endif
467#if defined _LIBC && defined USE_IN_LIBIO
468# include <libio/iolibio.h>
469# define fputs(s, f) _IO_fputs (s, f)
470#endif
471
472static void
473print_and_abort ()
474{
475 fputs (_("memory exhausted"), stderr);
476 fputc ('\n', stderr);
477 exit (obstack_exit_failure);
478}
479
480
481#if 0
482/* These are now turned off because the applications do not use it
483 and it uses bcopy via obstack_grow, which causes trouble on sysV. */
484
485/* Now define the functional versions of the obstack macros.
486 Define them to simply use the corresponding macros to do the job. */
487
488#if defined (__STDC__) && __STDC__
489/* These function definitions do not work with non-ANSI preprocessors;
490 they won't pass through the macro names in parentheses. */
491
492/* The function names appear in parentheses in order to prevent
493 the macro-definitions of the names from being expanded there. */
494
495POINTER (obstack_base) (obstack)
496 struct obstack *obstack;
497{
498 return obstack_base (obstack);
499}
500
501POINTER (obstack_next_free) (obstack)
502 struct obstack *obstack;
503{
504 return obstack_next_free (obstack);
505}
506
507int (obstack_object_size) (obstack)
508 struct obstack *obstack;
509{
510 return obstack_object_size (obstack);
511}
512
513int (obstack_room) (obstack)
514 struct obstack *obstack;
515{
516 return obstack_room (obstack);
517}
518
519int (obstack_make_room) (obstack, length)
520 struct obstack *obstack;
521 int length;
522{
523 return obstack_make_room (obstack, length);
524}
525
526void (obstack_grow) (obstack, pointer, length)
527 struct obstack *obstack;
528 POINTER pointer;
529 int length;
530{
531 obstack_grow (obstack, pointer, length);
532}
533
534void (obstack_grow0) (obstack, pointer, length)
535 struct obstack *obstack;
536 POINTER pointer;
537 int length;
538{
539 obstack_grow0 (obstack, pointer, length);
540}
541
542void (obstack_1grow) (obstack, character)
543 struct obstack *obstack;
544 int character;
545{
546 obstack_1grow (obstack, character);
547}
548
549void (obstack_blank) (obstack, length)
550 struct obstack *obstack;
551 int length;
552{
553 obstack_blank (obstack, length);
554}
555
556void (obstack_1grow_fast) (obstack, character)
557 struct obstack *obstack;
558 int character;
559{
560 obstack_1grow_fast (obstack, character);
561}
562
563void (obstack_blank_fast) (obstack, length)
564 struct obstack *obstack;
565 int length;
566{
567 obstack_blank_fast (obstack, length);
568}
569
570POINTER (obstack_finish) (obstack)
571 struct obstack *obstack;
572{
573 return obstack_finish (obstack);
574}
575
576POINTER (obstack_alloc) (obstack, length)
577 struct obstack *obstack;
578 int length;
579{
580 return obstack_alloc (obstack, length);
581}
582
583POINTER (obstack_copy) (obstack, pointer, length)
584 struct obstack *obstack;
585 POINTER pointer;
586 int length;
587{
588 return obstack_copy (obstack, pointer, length);
589}
590
591POINTER (obstack_copy0) (obstack, pointer, length)
592 struct obstack *obstack;
593 POINTER pointer;
594 int length;
595{
596 return obstack_copy0 (obstack, pointer, length);
597}
598
599#endif /* __STDC__ */
600
601#endif /* 0 */
602
603#endif /* !ELIDE_CODE */
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