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[glibc.git] / malloc / obstack.c
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1 /* obstack.c - subroutines used implicitly by object stack macros
2 Copyright (C) 1988-1994,96,97,98,99,2000 Free Software Foundation, Inc.
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.
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.
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.
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. */
22 #ifdef HAVE_CONFIG_H
23 #include <config.h>
24 #endif
26 #include "obstack.h"
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
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. */
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
51 #ifndef ELIDE_CODE
54 #if defined (__STDC__) && __STDC__
55 #define POINTER void *
56 #else
57 #define POINTER char *
58 #endif
60 /* Determine default alignment. */
61 struct 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. */
67 union fooround {long x; double d;};
68 #define DEFAULT_ROUNDING (sizeof (union fooround))
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
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__
86 static void print_and_abort (void);
87 void (*obstack_alloc_failed_handler) (void) = print_and_abort;
88 #else
89 static void print_and_abort ();
90 void (*obstack_alloc_failed_handler) () = print_and_abort;
91 #endif
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
100 int obstack_exit_failure = EXIT_FAILURE;
102 /* The non-GNU-C macros copy the obstack into this global variable
103 to avoid multiple evaluation. */
105 struct obstack *_obstack;
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. */
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)))
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)))
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
142 /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
143 Objects start on multiples of ALIGNMENT (0 means use default).
144 CHUNKFUN is the function to use to allocate chunks,
145 and FREEFUN the function to free them.
147 Return nonzero if successful, calls obstack_alloc_failed_handler if
148 allocation fails. */
151 _obstack_begin (h, size, alignment, chunkfun, freefun)
152 struct obstack *h;
153 int size;
154 int alignment;
155 #if defined (__STDC__) && __STDC__
156 POINTER (*chunkfun) (long);
157 void (*freefun) (void *);
158 #else
159 POINTER (*chunkfun) ();
160 void (*freefun) ();
161 #endif
163 register struct _obstack_chunk *chunk; /* points to new chunk */
165 if (alignment == 0)
166 alignment = (int) DEFAULT_ALIGNMENT;
167 if (size == 0)
168 /* Default size is what GNU malloc can fit in a 4096-byte block. */
170 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
171 Use the values for range checking, because if range checking is off,
172 the extra bytes won't be missed terribly, but if range checking is on
173 and we used a larger request, a whole extra 4096 bytes would be
174 allocated.
176 These number are irrelevant to the new GNU malloc. I suspect it is
177 less sensitive to the size of the request. */
178 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
179 + 4 + DEFAULT_ROUNDING - 1)
180 & ~(DEFAULT_ROUNDING - 1));
181 size = 4096 - extra;
184 #if defined (__STDC__) && __STDC__
185 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
186 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
187 #else
188 h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
189 h->freefun = freefun;
190 #endif
191 h->chunk_size = size;
192 h->alignment_mask = alignment - 1;
193 h->use_extra_arg = 0;
195 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
196 if (!chunk)
197 (*obstack_alloc_failed_handler) ();
198 h->next_free = h->object_base = chunk->contents;
199 h->chunk_limit = chunk->limit
200 = (char *) chunk + h->chunk_size;
201 chunk->prev = 0;
202 /* The initial chunk now contains no empty object. */
203 h->maybe_empty_object = 0;
204 h->alloc_failed = 0;
205 return 1;
209 _obstack_begin_1 (h, size, alignment, chunkfun, freefun, arg)
210 struct obstack *h;
211 int size;
212 int alignment;
213 #if defined (__STDC__) && __STDC__
214 POINTER (*chunkfun) (POINTER, long);
215 void (*freefun) (POINTER, POINTER);
216 #else
217 POINTER (*chunkfun) ();
218 void (*freefun) ();
219 #endif
220 POINTER arg;
222 register struct _obstack_chunk *chunk; /* points to new chunk */
224 if (alignment == 0)
225 alignment = (int) DEFAULT_ALIGNMENT;
226 if (size == 0)
227 /* Default size is what GNU malloc can fit in a 4096-byte block. */
229 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
230 Use the values for range checking, because if range checking is off,
231 the extra bytes won't be missed terribly, but if range checking is on
232 and we used a larger request, a whole extra 4096 bytes would be
233 allocated.
235 These number are irrelevant to the new GNU malloc. I suspect it is
236 less sensitive to the size of the request. */
237 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
238 + 4 + DEFAULT_ROUNDING - 1)
239 & ~(DEFAULT_ROUNDING - 1));
240 size = 4096 - extra;
243 #if defined(__STDC__) && __STDC__
244 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
245 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
246 #else
247 h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
248 h->freefun = freefun;
249 #endif
250 h->chunk_size = size;
251 h->alignment_mask = alignment - 1;
252 h->extra_arg = arg;
253 h->use_extra_arg = 1;
255 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
256 if (!chunk)
257 (*obstack_alloc_failed_handler) ();
258 h->next_free = h->object_base = chunk->contents;
259 h->chunk_limit = chunk->limit
260 = (char *) chunk + h->chunk_size;
261 chunk->prev = 0;
262 /* The initial chunk now contains no empty object. */
263 h->maybe_empty_object = 0;
264 h->alloc_failed = 0;
265 return 1;
268 /* Allocate a new current chunk for the obstack *H
269 on the assumption that LENGTH bytes need to be added
270 to the current object, or a new object of length LENGTH allocated.
271 Copies any partial object from the end of the old chunk
272 to the beginning of the new one. */
274 void
275 _obstack_newchunk (h, length)
276 struct obstack *h;
277 int length;
279 register struct _obstack_chunk *old_chunk = h->chunk;
280 register struct _obstack_chunk *new_chunk;
281 register long new_size;
282 register long obj_size = h->next_free - h->object_base;
283 register long i;
284 long already;
285 char *object_base;
287 /* Compute size for new chunk. */
288 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
289 if (new_size < h->chunk_size)
290 new_size = h->chunk_size;
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;
300 /* Compute an aligned object_base in the new chunk */
301 object_base =
302 __INT_TO_PTR ((__PTR_TO_INT (new_chunk->contents) + h->alignment_mask)
303 & ~ (h->alignment_mask));
305 /* Move the existing object to the new chunk.
306 Word at a time is fast and is safe if the object
307 is sufficiently aligned. */
308 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
310 for (i = obj_size / sizeof (COPYING_UNIT) - 1;
311 i >= 0; i--)
312 ((COPYING_UNIT *)object_base)[i]
313 = ((COPYING_UNIT *)h->object_base)[i];
314 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
315 but that can cross a page boundary on a machine
316 which does not do strict alignment for COPYING_UNITS. */
317 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
319 else
320 already = 0;
321 /* Copy remaining bytes one by one. */
322 for (i = already; i < obj_size; i++)
323 object_base[i] = h->object_base[i];
325 /* If the object just copied was the only data in OLD_CHUNK,
326 free that chunk and remove it from the chain.
327 But not if that chunk might contain an empty object. */
328 if (h->object_base == old_chunk->contents && ! h->maybe_empty_object)
330 new_chunk->prev = old_chunk->prev;
331 CALL_FREEFUN (h, old_chunk);
334 h->object_base = object_base;
335 h->next_free = h->object_base + obj_size;
336 /* The new chunk certainly contains no empty object yet. */
337 h->maybe_empty_object = 0;
340 /* Return nonzero if object OBJ has been allocated from obstack H.
341 This is here for debugging.
342 If you use it in a program, you are probably losing. */
344 #if defined (__STDC__) && __STDC__
345 /* Suppress -Wmissing-prototypes warning. We don't want to declare this in
346 obstack.h because it is just for debugging. */
347 int _obstack_allocated_p (struct obstack *h, POINTER obj);
348 #endif
351 _obstack_allocated_p (h, obj)
352 struct obstack *h;
353 POINTER obj;
355 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
356 register struct _obstack_chunk *plp; /* point to previous chunk if any */
358 lp = (h)->chunk;
359 /* We use >= rather than > since the object cannot be exactly at
360 the beginning of the chunk but might be an empty object exactly
361 at the end of an adjacent chunk. */
362 while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
364 plp = lp->prev;
365 lp = plp;
367 return lp != 0;
370 /* Free objects in obstack H, including OBJ and everything allocate
371 more recently than OBJ. If OBJ is zero, free everything in H. */
373 #undef obstack_free
375 /* This function has two names with identical definitions.
376 This is the first one, called from non-ANSI code. */
378 void
379 _obstack_free (h, obj)
380 struct obstack *h;
381 POINTER obj;
383 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
384 register struct _obstack_chunk *plp; /* point to previous chunk if any */
386 lp = h->chunk;
387 /* We use >= because there cannot be an object at the beginning of a chunk.
388 But there can be an empty object at that address
389 at the end of another chunk. */
390 while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
392 plp = lp->prev;
393 CALL_FREEFUN (h, lp);
394 lp = plp;
395 /* If we switch chunks, we can't tell whether the new current
396 chunk contains an empty object, so assume that it may. */
397 h->maybe_empty_object = 1;
399 if (lp)
401 h->object_base = h->next_free = (char *) (obj);
402 h->chunk_limit = lp->limit;
403 h->chunk = lp;
405 else if (obj != 0)
406 /* obj is not in any of the chunks! */
407 abort ();
410 /* This function is used from ANSI code. */
412 void
413 obstack_free (h, obj)
414 struct obstack *h;
415 POINTER obj;
417 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
418 register struct _obstack_chunk *plp; /* point to previous chunk if any */
420 lp = h->chunk;
421 /* We use >= because there cannot be an object at the beginning of a chunk.
422 But there can be an empty object at that address
423 at the end of another chunk. */
424 while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
426 plp = lp->prev;
427 CALL_FREEFUN (h, lp);
428 lp = plp;
429 /* If we switch chunks, we can't tell whether the new current
430 chunk contains an empty object, so assume that it may. */
431 h->maybe_empty_object = 1;
433 if (lp)
435 h->object_base = h->next_free = (char *) (obj);
436 h->chunk_limit = lp->limit;
437 h->chunk = lp;
439 else if (obj != 0)
440 /* obj is not in any of the chunks! */
441 abort ();
445 _obstack_memory_used (h)
446 struct obstack *h;
448 register struct _obstack_chunk* lp;
449 register int nbytes = 0;
451 for (lp = h->chunk; lp != 0; lp = lp->prev)
453 nbytes += lp->limit - (char *) lp;
455 return nbytes;
458 /* Define the error handler. */
459 #ifndef _
460 # if defined HAVE_LIBINTL_H || defined _LIBC
461 # include <libintl.h>
462 # ifndef _
463 # define _(Str) gettext (Str)
464 # endif
465 # else
466 # define _(Str) (Str)
467 # endif
468 #endif
469 #if defined _LIBC && defined USE_IN_LIBIO
470 # include <libio/iolibio.h>
471 # define fputs(s, f) _IO_fputs (s, f)
472 #endif
474 static void
475 print_and_abort ()
477 fputs (_("memory exhausted"), stderr);
478 fputc ('\n', stderr);
479 exit (obstack_exit_failure);
482 #if 0
483 /* These are now turned off because the applications do not use it
484 and it uses bcopy via obstack_grow, which causes trouble on sysV. */
486 /* Now define the functional versions of the obstack macros.
487 Define them to simply use the corresponding macros to do the job. */
489 #if defined (__STDC__) && __STDC__
490 /* These function definitions do not work with non-ANSI preprocessors;
491 they won't pass through the macro names in parentheses. */
493 /* The function names appear in parentheses in order to prevent
494 the macro-definitions of the names from being expanded there. */
496 POINTER (obstack_base) (obstack)
497 struct obstack *obstack;
499 return obstack_base (obstack);
502 POINTER (obstack_next_free) (obstack)
503 struct obstack *obstack;
505 return obstack_next_free (obstack);
508 int (obstack_object_size) (obstack)
509 struct obstack *obstack;
511 return obstack_object_size (obstack);
514 int (obstack_room) (obstack)
515 struct obstack *obstack;
517 return obstack_room (obstack);
520 int (obstack_make_room) (obstack, length)
521 struct obstack *obstack;
522 int length;
524 return obstack_make_room (obstack, length);
527 void (obstack_grow) (obstack, data, length)
528 struct obstack *obstack;
529 const POINTER data;
530 int length;
532 obstack_grow (obstack, data, length);
535 void (obstack_grow0) (obstack, data, length)
536 struct obstack *obstack;
537 const POINTER data;
538 int length;
540 obstack_grow0 (obstack, data, length);
543 void (obstack_1grow) (obstack, character)
544 struct obstack *obstack;
545 int character;
547 obstack_1grow (obstack, character);
550 void (obstack_blank) (obstack, length)
551 struct obstack *obstack;
552 int length;
554 obstack_blank (obstack, length);
557 void (obstack_1grow_fast) (obstack, character)
558 struct obstack *obstack;
559 int character;
561 obstack_1grow_fast (obstack, character);
564 void (obstack_blank_fast) (obstack, length)
565 struct obstack *obstack;
566 int length;
568 obstack_blank_fast (obstack, length);
571 POINTER (obstack_finish) (obstack)
572 struct obstack *obstack;
574 return obstack_finish (obstack);
577 POINTER (obstack_alloc) (obstack, length)
578 struct obstack *obstack;
579 int length;
581 return obstack_alloc (obstack, length);
584 POINTER (obstack_copy) (obstack, address, length)
585 struct obstack *obstack;
586 const POINTER address;
587 int length;
589 return obstack_copy (obstack, address, length);
592 POINTER (obstack_copy0) (obstack, address, length)
593 struct obstack *obstack;
594 const POINTER address;
595 int length;
597 return obstack_copy0 (obstack, address, length);
600 #endif /* __STDC__ */
602 #endif /* 0 */
604 #endif /* !ELIDE_CODE */