1 /* obstack.c - subroutines used implicitly by object stack macros
2 Copyright (C) 1988-2013 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
26 # include <shlib-compat.h>
31 /* NOTE BEFORE MODIFYING THIS FILE: This version number must be
32 incremented whenever callers compiled using an old obstack.h can no
33 longer properly call the functions in this obstack.c. */
34 #define OBSTACK_INTERFACE_VERSION 1
36 /* Comment out all this code if we are using the GNU C Library, and are not
37 actually compiling the library itself, and the installed library
38 supports the same library interface we do. This code is part of the GNU
39 C Library, but also included in many other GNU distributions. Compiling
40 and linking in this code is a waste when using the GNU C library
41 (especially if it is a shared library). Rather than having every GNU
42 program understand `configure --with-gnu-libc' and omit the object
43 files, it is simpler to just do this in the source for each such file. */
45 #include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */
46 #if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1
47 # include <gnu-versions.h>
48 # if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION
59 # include <inttypes.h>
61 # if HAVE_STDINT_H || defined _LIBC
65 /* Determine default alignment. */
77 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
78 But in fact it might be less smart and round addresses to as much as
79 DEFAULT_ROUNDING. So we prepare for it to do that. */
82 DEFAULT_ALIGNMENT
= offsetof (struct fooalign
, u
),
83 DEFAULT_ROUNDING
= sizeof (union fooround
)
86 /* When we copy a long block of data, this is the unit to do it with.
87 On some machines, copying successive ints does not work;
88 in such a case, redefine COPYING_UNIT to `long' (if that works)
89 or `char' as a last resort. */
91 # define COPYING_UNIT int
95 /* The functions allocating more room by calling `obstack_chunk_alloc'
96 jump to the handler pointed to by `obstack_alloc_failed_handler'.
97 This can be set to a user defined function which should either
98 abort gracefully or use longjump - but shouldn't return. This
99 variable by default points to the internal function
100 `print_and_abort'. */
101 static void print_and_abort (void);
102 void (*obstack_alloc_failed_handler
) (void) = print_and_abort
;
104 /* Exit value used when `print_and_abort' is used. */
107 int obstack_exit_failure
= EXIT_FAILURE
;
109 # include "exitfail.h"
110 # define obstack_exit_failure exit_failure
114 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
115 /* A looong time ago (before 1994, anyway; we're not sure) this global variable
116 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C
117 library still exports it because somebody might use it. */
118 struct obstack
*_obstack_compat
;
119 compat_symbol (libc
, _obstack_compat
, _obstack
, GLIBC_2_0
);
123 /* Define a macro that either calls functions with the traditional malloc/free
124 calling interface, or calls functions with the mmalloc/mfree interface
125 (that adds an extra first argument), based on the state of use_extra_arg.
126 For free, do not use ?:, since some compilers, like the MIPS compilers,
127 do not allow (expr) ? void : void. */
129 # define CALL_CHUNKFUN(h, size) \
130 (((h) -> use_extra_arg) \
131 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
132 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
134 # define CALL_FREEFUN(h, old_chunk) \
136 if ((h) -> use_extra_arg) \
137 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
139 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
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.
148 Return nonzero if successful, calls obstack_alloc_failed_handler if
152 _obstack_begin (struct obstack
*h
,
153 int size
, int alignment
,
154 void *(*chunkfun
) (long),
155 void (*freefun
) (void *))
157 register struct _obstack_chunk
*chunk
; /* points to new chunk */
160 alignment
= DEFAULT_ALIGNMENT
;
162 /* Default size is what GNU malloc can fit in a 4096-byte block. */
164 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
165 Use the values for range checking, because if range checking is off,
166 the extra bytes won't be missed terribly, but if range checking is on
167 and we used a larger request, a whole extra 4096 bytes would be
170 These number are irrelevant to the new GNU malloc. I suspect it is
171 less sensitive to the size of the request. */
172 int extra
= ((((12 + DEFAULT_ROUNDING
- 1) & ~(DEFAULT_ROUNDING
- 1))
173 + 4 + DEFAULT_ROUNDING
- 1)
174 & ~(DEFAULT_ROUNDING
- 1));
178 h
->chunkfun
= (struct _obstack_chunk
* (*)(void *, long)) chunkfun
;
179 h
->freefun
= (void (*) (void *, struct _obstack_chunk
*)) freefun
;
180 h
->chunk_size
= size
;
181 h
->alignment_mask
= alignment
- 1;
182 h
->use_extra_arg
= 0;
184 chunk
= h
->chunk
= CALL_CHUNKFUN (h
, h
-> chunk_size
);
186 (*obstack_alloc_failed_handler
) ();
187 h
->next_free
= h
->object_base
= __PTR_ALIGN ((char *) chunk
, chunk
->contents
,
189 h
->chunk_limit
= chunk
->limit
190 = (char *) chunk
+ h
->chunk_size
;
192 /* The initial chunk now contains no empty object. */
193 h
->maybe_empty_object
= 0;
199 _obstack_begin_1 (struct obstack
*h
, int size
, int alignment
,
200 void *(*chunkfun
) (void *, long),
201 void (*freefun
) (void *, void *),
204 register struct _obstack_chunk
*chunk
; /* points to new chunk */
207 alignment
= DEFAULT_ALIGNMENT
;
209 /* Default size is what GNU malloc can fit in a 4096-byte block. */
211 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
212 Use the values for range checking, because if range checking is off,
213 the extra bytes won't be missed terribly, but if range checking is on
214 and we used a larger request, a whole extra 4096 bytes would be
217 These number are irrelevant to the new GNU malloc. I suspect it is
218 less sensitive to the size of the request. */
219 int extra
= ((((12 + DEFAULT_ROUNDING
- 1) & ~(DEFAULT_ROUNDING
- 1))
220 + 4 + DEFAULT_ROUNDING
- 1)
221 & ~(DEFAULT_ROUNDING
- 1));
225 h
->chunkfun
= (struct _obstack_chunk
* (*)(void *,long)) chunkfun
;
226 h
->freefun
= (void (*) (void *, struct _obstack_chunk
*)) freefun
;
227 h
->chunk_size
= size
;
228 h
->alignment_mask
= alignment
- 1;
230 h
->use_extra_arg
= 1;
232 chunk
= h
->chunk
= CALL_CHUNKFUN (h
, h
-> chunk_size
);
234 (*obstack_alloc_failed_handler
) ();
235 h
->next_free
= h
->object_base
= __PTR_ALIGN ((char *) chunk
, chunk
->contents
,
237 h
->chunk_limit
= chunk
->limit
238 = (char *) chunk
+ h
->chunk_size
;
240 /* The initial chunk now contains no empty object. */
241 h
->maybe_empty_object
= 0;
246 /* Allocate a new current chunk for the obstack *H
247 on the assumption that LENGTH bytes need to be added
248 to the current object, or a new object of length LENGTH allocated.
249 Copies any partial object from the end of the old chunk
250 to the beginning of the new one. */
253 _obstack_newchunk (struct obstack
*h
, int length
)
255 register struct _obstack_chunk
*old_chunk
= h
->chunk
;
256 register struct _obstack_chunk
*new_chunk
;
257 register long new_size
;
258 register long obj_size
= h
->next_free
- h
->object_base
;
263 /* Compute size for new chunk. */
264 new_size
= (obj_size
+ length
) + (obj_size
>> 3) + h
->alignment_mask
+ 100;
265 if (new_size
< h
->chunk_size
)
266 new_size
= h
->chunk_size
;
268 /* Allocate and initialize the new chunk. */
269 new_chunk
= CALL_CHUNKFUN (h
, new_size
);
271 (*obstack_alloc_failed_handler
) ();
272 h
->chunk
= new_chunk
;
273 new_chunk
->prev
= old_chunk
;
274 new_chunk
->limit
= h
->chunk_limit
= (char *) new_chunk
+ new_size
;
276 /* Compute an aligned object_base in the new chunk */
278 __PTR_ALIGN ((char *) new_chunk
, new_chunk
->contents
, h
->alignment_mask
);
280 /* Move the existing object to the new chunk.
281 Word at a time is fast and is safe if the object
282 is sufficiently aligned. */
283 if (h
->alignment_mask
+ 1 >= DEFAULT_ALIGNMENT
)
285 for (i
= obj_size
/ sizeof (COPYING_UNIT
) - 1;
287 ((COPYING_UNIT
*)object_base
)[i
]
288 = ((COPYING_UNIT
*)h
->object_base
)[i
];
289 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
290 but that can cross a page boundary on a machine
291 which does not do strict alignment for COPYING_UNITS. */
292 already
= obj_size
/ sizeof (COPYING_UNIT
) * sizeof (COPYING_UNIT
);
296 /* Copy remaining bytes one by one. */
297 for (i
= already
; i
< obj_size
; i
++)
298 object_base
[i
] = h
->object_base
[i
];
300 /* If the object just copied was the only data in OLD_CHUNK,
301 free that chunk and remove it from the chain.
302 But not if that chunk might contain an empty object. */
303 if (! h
->maybe_empty_object
305 == __PTR_ALIGN ((char *) old_chunk
, old_chunk
->contents
,
308 new_chunk
->prev
= old_chunk
->prev
;
309 CALL_FREEFUN (h
, old_chunk
);
312 h
->object_base
= object_base
;
313 h
->next_free
= h
->object_base
+ obj_size
;
314 /* The new chunk certainly contains no empty object yet. */
315 h
->maybe_empty_object
= 0;
318 libc_hidden_def (_obstack_newchunk
)
321 /* Return nonzero if object OBJ has been allocated from obstack H.
322 This is here for debugging.
323 If you use it in a program, you are probably losing. */
325 /* Suppress -Wmissing-prototypes warning. We don't want to declare this in
326 obstack.h because it is just for debugging. */
327 int _obstack_allocated_p (struct obstack
*h
, void *obj
);
330 _obstack_allocated_p (struct obstack
*h
, void *obj
)
332 register struct _obstack_chunk
*lp
; /* below addr of any objects in this chunk */
333 register struct _obstack_chunk
*plp
; /* point to previous chunk if any */
336 /* We use >= rather than > since the object cannot be exactly at
337 the beginning of the chunk but might be an empty object exactly
338 at the end of an adjacent chunk. */
339 while (lp
!= 0 && ((void *) lp
>= obj
|| (void *) (lp
)->limit
< obj
))
347 /* Free objects in obstack H, including OBJ and everything allocate
348 more recently than OBJ. If OBJ is zero, free everything in H. */
353 obstack_free (struct obstack
*h
, void *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 */
359 /* We use >= because there cannot be an object at the beginning of a chunk.
360 But there can be an empty object at that address
361 at the end of another chunk. */
362 while (lp
!= 0 && ((void *) lp
>= obj
|| (void *) (lp
)->limit
< obj
))
365 CALL_FREEFUN (h
, lp
);
367 /* If we switch chunks, we can't tell whether the new current
368 chunk contains an empty object, so assume that it may. */
369 h
->maybe_empty_object
= 1;
373 h
->object_base
= h
->next_free
= (char *) (obj
);
374 h
->chunk_limit
= lp
->limit
;
378 /* obj is not in any of the chunks! */
383 /* Older versions of libc used a function _obstack_free intended to be
384 called by non-GCC compilers. */
385 strong_alias (obstack_free
, _obstack_free
)
389 _obstack_memory_used (struct obstack
*h
)
391 register struct _obstack_chunk
* lp
;
392 register int nbytes
= 0;
394 for (lp
= h
->chunk
; lp
!= 0; lp
= lp
->prev
)
396 nbytes
+= lp
->limit
- (char *) lp
;
401 /* Define the error handler. */
403 # include <libintl.h>
405 # include "gettext.h"
408 # define _(msgid) gettext (msgid)
412 # include <libio/iolibio.h>
415 # ifndef __attribute__
416 /* This feature is available in gcc versions 2.5 and later. */
417 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
418 # define __attribute__(Spec) /* empty */
423 __attribute__ ((noreturn
))
424 print_and_abort (void)
426 /* Don't change any of these strings. Yes, it would be possible to add
427 the newline to the string and use fputs or so. But this must not
428 happen because the "memory exhausted" message appears in other places
429 like this and the translation should be reused instead of creating
430 a very similar string which requires a separate translation. */
432 (void) __fxprintf (NULL
, "%s\n", _("memory exhausted"));
434 fprintf (stderr
, "%s\n", _("memory exhausted"));
436 exit (obstack_exit_failure
);
439 #endif /* !ELIDE_CODE */