1 /* obstack.h - object stack macros
2 Copyright (C) 1988-1994,1996-1999,2003,2004,2005,2009,2011,2012
3 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
22 All the apparent functions defined here are macros. The idea
23 is that you would use these pre-tested macros to solve a
24 very specific set of problems, and they would run fast.
25 Caution: no side-effects in arguments please!! They may be
26 evaluated MANY times!!
28 These macros operate a stack of objects. Each object starts life
29 small, and may grow to maturity. (Consider building a word syllable
30 by syllable.) An object can move while it is growing. Once it has
31 been "finished" it never changes address again. So the "top of the
32 stack" is typically an immature growing object, while the rest of the
33 stack is of mature, fixed size and fixed address objects.
35 These routines grab large chunks of memory, using a function you
36 supply, called `obstack_chunk_alloc'. On occasion, they free chunks,
37 by calling `obstack_chunk_free'. You must define them and declare
38 them before using any obstack macros.
40 Each independent stack is represented by a `struct obstack'.
41 Each of the obstack macros expects a pointer to such a structure
42 as the first argument.
44 One motivation for this package is the problem of growing char strings
45 in symbol tables. Unless you are "fascist pig with a read-only mind"
46 --Gosper's immortal quote from HAKMEM item 154, out of context--you
47 would not like to put any arbitrary upper limit on the length of your
50 In practice this often means you will build many short symbols and a
51 few long symbols. At the time you are reading a symbol you don't know
52 how long it is. One traditional method is to read a symbol into a
53 buffer, realloc()ating the buffer every time you try to read a symbol
54 that is longer than the buffer. This is beaut, but you still will
55 want to copy the symbol from the buffer to a more permanent
56 symbol-table entry say about half the time.
58 With obstacks, you can work differently. Use one obstack for all symbol
59 names. As you read a symbol, grow the name in the obstack gradually.
60 When the name is complete, finalize it. Then, if the symbol exists already,
61 free the newly read name.
63 The way we do this is to take a large chunk, allocating memory from
64 low addresses. When you want to build a symbol in the chunk you just
65 add chars above the current "high water mark" in the chunk. When you
66 have finished adding chars, because you got to the end of the symbol,
67 you know how long the chars are, and you can create a new object.
68 Mostly the chars will not burst over the highest address of the chunk,
69 because you would typically expect a chunk to be (say) 100 times as
70 long as an average object.
72 In case that isn't clear, when we have enough chars to make up
73 the object, THEY ARE ALREADY CONTIGUOUS IN THE CHUNK (guaranteed)
74 so we just point to it where it lies. No moving of chars is
75 needed and this is the second win: potentially long strings need
76 never be explicitly shuffled. Once an object is formed, it does not
77 change its address during its lifetime.
79 When the chars burst over a chunk boundary, we allocate a larger
80 chunk, and then copy the partly formed object from the end of the old
81 chunk to the beginning of the new larger chunk. We then carry on
82 accreting characters to the end of the object as we normally would.
84 A special macro is provided to add a single char at a time to a
85 growing object. This allows the use of register variables, which
86 break the ordinary 'growth' macro.
89 We allocate large chunks.
90 We carve out one object at a time from the current chunk.
91 Once carved, an object never moves.
92 We are free to append data of any size to the currently
94 Exactly one object is growing in an obstack at any one time.
95 You can run one obstack per control block.
96 You may have as many control blocks as you dare.
97 Because of the way we do it, you can `unwind' an obstack
98 back to a previous state. (You may remove objects much
99 as you would with a stack.)
103 /* Don't do the contents of this file more than once. */
112 /* We need the type of a pointer subtraction. If __PTRDIFF_TYPE__ is
113 defined, as with GNU C, use that; that way we don't pollute the
114 namespace with <stddef.h>'s symbols. Otherwise, include <stddef.h>
115 and use ptrdiff_t. */
117 #ifdef __PTRDIFF_TYPE__
118 # define PTR_INT_TYPE __PTRDIFF_TYPE__
121 # define PTR_INT_TYPE ptrdiff_t
124 /* If B is the base of an object addressed by P, return the result of
125 aligning P to the next multiple of A + 1. B and P must be of type
126 char *. A + 1 must be a power of 2. */
128 #define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A)))
130 /* Similiar to _BPTR_ALIGN (B, P, A), except optimize the common case
131 where pointers can be converted to integers, aligned as integers,
132 and converted back again. If PTR_INT_TYPE is narrower than a
133 pointer (e.g., the AS/400), play it safe and compute the alignment
134 relative to B. Otherwise, use the faster strategy of computing the
135 alignment relative to 0. */
137 #define __PTR_ALIGN(B, P, A) \
138 __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \
143 struct _obstack_chunk /* Lives at front of each chunk. */
145 char *limit; /* 1 past end of this chunk */
146 struct _obstack_chunk *prev; /* address of prior chunk or NULL */
147 char contents[4]; /* objects begin here */
150 struct obstack /* control current object in current chunk */
152 long chunk_size; /* preferred size to allocate chunks in */
153 struct _obstack_chunk *chunk; /* address of current struct obstack_chunk */
154 char *object_base; /* address of object we are building */
155 char *next_free; /* where to add next char to current object */
156 char *chunk_limit; /* address of char after current chunk */
159 PTR_INT_TYPE tempint;
161 } temp; /* Temporary for some macros. */
162 int alignment_mask; /* Mask of alignment for each object. */
163 /* These prototypes vary based on `use_extra_arg', and we use
164 casts to the prototypeless function type in all assignments,
165 but having prototypes here quiets -Wstrict-prototypes. */
166 struct _obstack_chunk *(*chunkfun) (void *, long);
167 void (*freefun) (void *, struct _obstack_chunk *);
168 void *extra_arg; /* first arg for chunk alloc/dealloc funcs */
169 unsigned use_extra_arg:1; /* chunk alloc/dealloc funcs take extra arg */
170 unsigned maybe_empty_object:1;/* There is a possibility that the current
171 chunk contains a zero-length object. This
172 prevents freeing the chunk if we allocate
173 a bigger chunk to replace it. */
174 unsigned alloc_failed:1; /* No longer used, as we now call the failed
175 handler on error, but retained for binary
179 static void _obstack_newchunk (struct obstack *h, int length);
181 /* Exit value used when `print_and_abort' is used. */
182 extern int obstack_exit_failure;
184 /* Pointer to beginning of object being allocated or to be allocated next.
185 Note that this might not be the final address of the object
186 because a new chunk might be needed to hold the final size. */
188 #define obstack_base(h) ((void *) (h)->object_base)
190 /* Size for allocating ordinary chunks. */
192 #define obstack_chunk_size(h) ((h)->chunk_size)
194 /* Pointer to next byte not yet allocated in current chunk. */
196 #define obstack_next_free(h) ((h)->next_free)
198 /* Mask specifying low bits that should be clear in address of an object. */
200 #define obstack_alignment_mask(h) ((h)->alignment_mask)
202 /* To prevent prototype warnings provide complete argument list. */
203 #define obstack_init(h) \
204 _obstack_begin ((h), 0, 0, \
205 (void *(*) (long)) obstack_chunk_alloc, \
206 (void (*) (void *)) obstack_chunk_free)
208 #define obstack_begin(h, size) \
209 _obstack_begin ((h), (size), 0, \
210 (void *(*) (long)) obstack_chunk_alloc, \
211 (void (*) (void *)) obstack_chunk_free)
213 #define obstack_specify_allocation(h, size, alignment, chunkfun, freefun) \
214 _obstack_begin ((h), (size), (alignment), \
215 (void *(*) (long)) (chunkfun), \
216 (void (*) (void *)) (freefun))
218 #define obstack_specify_allocation_with_arg(h, size, alignment, chunkfun, freefun, arg) \
219 _obstack_begin_1 ((h), (size), (alignment), \
220 (void *(*) (void *, long)) (chunkfun), \
221 (void (*) (void *, void *)) (freefun), (arg))
223 #define obstack_chunkfun(h, newchunkfun) \
224 ((h) -> chunkfun = (struct _obstack_chunk *(*)(void *, long)) (newchunkfun))
226 #define obstack_freefun(h, newfreefun) \
227 ((h) -> freefun = (void (*)(void *, struct _obstack_chunk *)) (newfreefun))
229 #define obstack_1grow_fast(h,achar) (*((h)->next_free)++ = (achar))
231 #define obstack_blank_fast(h,n) ((h)->next_free += (n))
233 #define obstack_memory_used(h) _obstack_memory_used (h)
236 /* NextStep 2.0 cc is really gcc 1.93 but it defines __GNUC__ = 2 and
237 does not implement __extension__. But that compiler doesn't define
239 # if __GNUC__ < 2 || (__NeXT__ && !__GNUC_MINOR__)
240 # define __extension__
243 /* For GNU C, if not -traditional,
244 we can define these macros to compute all args only once
245 without using a global variable.
246 Also, we can avoid using the `temp' slot, to make faster code. */
248 # define obstack_object_size(OBSTACK) \
250 ({ struct obstack const *__o = (OBSTACK); \
251 (unsigned) (__o->next_free - __o->object_base); })
253 # define obstack_room(OBSTACK) \
255 ({ struct obstack const *__o = (OBSTACK); \
256 (unsigned) (__o->chunk_limit - __o->next_free); })
258 # define obstack_make_room(OBSTACK,length) \
260 ({ struct obstack *__o = (OBSTACK); \
261 int __len = (length); \
262 if (__o->chunk_limit - __o->next_free < __len) \
263 _obstack_newchunk (__o, __len); \
266 # define obstack_empty_p(OBSTACK) \
268 ({ struct obstack const *__o = (OBSTACK); \
269 (__o->chunk->prev == 0 \
270 && __o->next_free == __PTR_ALIGN ((char *) __o->chunk, \
271 __o->chunk->contents, \
272 __o->alignment_mask)); })
274 # define obstack_grow(OBSTACK,where,length) \
276 ({ struct obstack *__o = (OBSTACK); \
277 int __len = (length); \
278 if (__o->next_free + __len > __o->chunk_limit) \
279 _obstack_newchunk (__o, __len); \
280 memcpy (__o->next_free, where, __len); \
281 __o->next_free += __len; \
284 # define obstack_grow0(OBSTACK,where,length) \
286 ({ struct obstack *__o = (OBSTACK); \
287 int __len = (length); \
288 if (__o->next_free + __len + 1 > __o->chunk_limit) \
289 _obstack_newchunk (__o, __len + 1); \
290 memcpy (__o->next_free, where, __len); \
291 __o->next_free += __len; \
292 *(__o->next_free)++ = 0; \
295 # define obstack_1grow(OBSTACK,datum) \
297 ({ struct obstack *__o = (OBSTACK); \
298 if (__o->next_free + 1 > __o->chunk_limit) \
299 _obstack_newchunk (__o, 1); \
300 obstack_1grow_fast (__o, datum); \
303 /* These assume that the obstack alignment is good enough for pointers
304 or ints, and that the data added so far to the current object
305 shares that much alignment. */
307 # define obstack_ptr_grow(OBSTACK,datum) \
309 ({ struct obstack *__o = (OBSTACK); \
310 if (__o->next_free + sizeof (void *) > __o->chunk_limit) \
311 _obstack_newchunk (__o, sizeof (void *)); \
312 obstack_ptr_grow_fast (__o, datum); }) \
314 # define obstack_int_grow(OBSTACK,datum) \
316 ({ struct obstack *__o = (OBSTACK); \
317 if (__o->next_free + sizeof (int) > __o->chunk_limit) \
318 _obstack_newchunk (__o, sizeof (int)); \
319 obstack_int_grow_fast (__o, datum); })
321 # define obstack_ptr_grow_fast(OBSTACK,aptr) \
323 ({ struct obstack *__o1 = (OBSTACK); \
324 *(const void **) __o1->next_free = (aptr); \
325 __o1->next_free += sizeof (const void *); \
328 # define obstack_int_grow_fast(OBSTACK,aint) \
330 ({ struct obstack *__o1 = (OBSTACK); \
331 *(int *) __o1->next_free = (aint); \
332 __o1->next_free += sizeof (int); \
335 # define obstack_blank(OBSTACK,length) \
337 ({ struct obstack *__o = (OBSTACK); \
338 int __len = (length); \
339 if (__o->chunk_limit - __o->next_free < __len) \
340 _obstack_newchunk (__o, __len); \
341 obstack_blank_fast (__o, __len); \
344 # define obstack_alloc(OBSTACK,length) \
346 ({ struct obstack *__h = (OBSTACK); \
347 obstack_blank (__h, (length)); \
348 obstack_finish (__h); })
350 # define obstack_copy(OBSTACK,where,length) \
352 ({ struct obstack *__h = (OBSTACK); \
353 obstack_grow (__h, (where), (length)); \
354 obstack_finish (__h); })
356 # define obstack_copy0(OBSTACK,where,length) \
358 ({ struct obstack *__h = (OBSTACK); \
359 obstack_grow0 (__h, (where), (length)); \
360 obstack_finish (__h); })
362 /* The local variable is named __o1 to avoid a name conflict
363 when obstack_blank is called. */
364 # define obstack_finish(OBSTACK) \
366 ({ struct obstack *__o1 = (OBSTACK); \
367 void *__value = (void *) __o1->object_base; \
368 if (__o1->next_free == __value) \
369 __o1->maybe_empty_object = 1; \
371 = __PTR_ALIGN (__o1->object_base, __o1->next_free, \
372 __o1->alignment_mask); \
373 if (__o1->next_free - (char *)__o1->chunk \
374 > __o1->chunk_limit - (char *)__o1->chunk) \
375 __o1->next_free = __o1->chunk_limit; \
376 __o1->object_base = __o1->next_free; \
379 # define obstack_free(OBSTACK, OBJ) \
381 ({ struct obstack *__o = (OBSTACK); \
382 void *__obj = (OBJ); \
383 if (__obj > (void *)__o->chunk && __obj < (void *)__o->chunk_limit) \
384 __o->next_free = __o->object_base = (char *)__obj; \
385 else (obstack_free_func) (__o, __obj); })
387 #else /* not __GNUC__ */
389 # define obstack_object_size(h) \
390 (unsigned) ((h)->next_free - (h)->object_base)
392 # define obstack_room(h) \
393 (unsigned) ((h)->chunk_limit - (h)->next_free)
395 # define obstack_empty_p(h) \
396 ((h)->chunk->prev == 0 \
397 && (h)->next_free == __PTR_ALIGN ((char *) (h)->chunk, \
398 (h)->chunk->contents, \
399 (h)->alignment_mask))
401 /* Note that the call to _obstack_newchunk is enclosed in (..., 0)
402 so that we can avoid having void expressions
403 in the arms of the conditional expression.
404 Casting the third operand to void was tried before,
405 but some compilers won't accept it. */
407 # define obstack_make_room(h,length) \
408 ( (h)->temp.tempint = (length), \
409 (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit) \
410 ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0))
412 # define obstack_grow(h,where,length) \
413 ( (h)->temp.tempint = (length), \
414 (((h)->next_free + (h)->temp.tempint > (h)->chunk_limit) \
415 ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0), \
416 memcpy ((h)->next_free, where, (h)->temp.tempint), \
417 (h)->next_free += (h)->temp.tempint)
419 # define obstack_grow0(h,where,length) \
420 ( (h)->temp.tempint = (length), \
421 (((h)->next_free + (h)->temp.tempint + 1 > (h)->chunk_limit) \
422 ? (_obstack_newchunk ((h), (h)->temp.tempint + 1), 0) : 0), \
423 memcpy ((h)->next_free, where, (h)->temp.tempint), \
424 (h)->next_free += (h)->temp.tempint, \
425 *((h)->next_free)++ = 0)
427 # define obstack_1grow(h,datum) \
428 ( (((h)->next_free + 1 > (h)->chunk_limit) \
429 ? (_obstack_newchunk ((h), 1), 0) : 0), \
430 obstack_1grow_fast (h, datum))
432 # define obstack_ptr_grow(h,datum) \
433 ( (((h)->next_free + sizeof (char *) > (h)->chunk_limit) \
434 ? (_obstack_newchunk ((h), sizeof (char *)), 0) : 0), \
435 obstack_ptr_grow_fast (h, datum))
437 # define obstack_int_grow(h,datum) \
438 ( (((h)->next_free + sizeof (int) > (h)->chunk_limit) \
439 ? (_obstack_newchunk ((h), sizeof (int)), 0) : 0), \
440 obstack_int_grow_fast (h, datum))
442 # define obstack_ptr_grow_fast(h,aptr) \
443 (((const void **) ((h)->next_free += sizeof (void *)))[-1] = (aptr))
445 # define obstack_int_grow_fast(h,aint) \
446 (((int *) ((h)->next_free += sizeof (int)))[-1] = (aint))
448 # define obstack_blank(h,length) \
449 ( (h)->temp.tempint = (length), \
450 (((h)->chunk_limit - (h)->next_free < (h)->temp.tempint) \
451 ? (_obstack_newchunk ((h), (h)->temp.tempint), 0) : 0), \
452 obstack_blank_fast (h, (h)->temp.tempint))
454 # define obstack_alloc(h,length) \
455 (obstack_blank ((h), (length)), obstack_finish ((h)))
457 # define obstack_copy(h,where,length) \
458 (obstack_grow ((h), (where), (length)), obstack_finish ((h)))
460 # define obstack_copy0(h,where,length) \
461 (obstack_grow0 ((h), (where), (length)), obstack_finish ((h)))
463 # define obstack_finish(h) \
464 ( ((h)->next_free == (h)->object_base \
465 ? (((h)->maybe_empty_object = 1), 0) \
467 (h)->temp.tempptr = (h)->object_base, \
469 = __PTR_ALIGN ((h)->object_base, (h)->next_free, \
470 (h)->alignment_mask), \
471 (((h)->next_free - (char *) (h)->chunk \
472 > (h)->chunk_limit - (char *) (h)->chunk) \
473 ? ((h)->next_free = (h)->chunk_limit) : 0), \
474 (h)->object_base = (h)->next_free, \
477 # define obstack_free(h,obj) \
478 ( (h)->temp.tempint = (char *) (obj) - (char *) (h)->chunk, \
479 ((((h)->temp.tempint > 0 \
480 && (h)->temp.tempint < (h)->chunk_limit - (char *) (h)->chunk)) \
481 ? (((h)->next_free = (h)->object_base \
482 = (h)->temp.tempint + (char *) (h)->chunk), 0) \
483 : ((obstack_free_func) ((h), (h)->temp.tempint + (char *) (h)->chunk), 0)))
485 #endif /* not __GNUC__ */
487 /* START LOCAL ADDITION */
488 static inline int obstack_printf(struct obstack *obst, const char *fmt, ...)
495 len = vsnprintf(buf, sizeof(buf), fmt, ap);
496 obstack_grow(obst, buf, len);
501 /* Determine default alignment. */
513 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
514 But in fact it might be less smart and round addresses to as much as
515 DEFAULT_ROUNDING. So we prepare for it to do that. */
518 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u),
519 DEFAULT_ROUNDING = sizeof (union fooround)
522 /* When we copy a long block of data, this is the unit to do it with.
523 On some machines, copying successive ints does not work;
524 in such a case, redefine COPYING_UNIT to `long' (if that works)
525 or `char' as a last resort. */
526 # ifndef COPYING_UNIT
527 # define COPYING_UNIT int
531 /* The functions allocating more room by calling `obstack_chunk_alloc'
532 jump to the handler pointed to by `obstack_alloc_failed_handler'.
533 This can be set to a user defined function which should either
534 abort gracefully or use longjump - but shouldn't return. This
535 variable by default points to the internal function
536 `print_and_abort'. */
537 static void print_and_abort (void);
540 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
541 /* A looong time ago (before 1994, anyway; we're not sure) this global variable
542 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C
543 library still exports it because somebody might use it. */
544 struct obstack *_obstack_compat;
545 compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0);
549 /* Define a macro that either calls functions with the traditional malloc/free
550 calling interface, or calls functions with the mmalloc/mfree interface
551 (that adds an extra first argument), based on the state of use_extra_arg.
552 For free, do not use ?:, since some compilers, like the MIPS compilers,
553 do not allow (expr) ? void : void. */
555 # define CALL_CHUNKFUN(h, size) \
556 (((h) -> use_extra_arg) \
557 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
558 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
560 # define CALL_FREEFUN(h, old_chunk) \
562 if ((h) -> use_extra_arg) \
563 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
565 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
569 /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default).
570 Objects start on multiples of ALIGNMENT (0 means use default).
571 CHUNKFUN is the function to use to allocate chunks,
572 and FREEFUN the function to free them.
573 Return nonzero if successful, calls obstack_alloc_failed_handler if
576 static int _obstack_begin (struct obstack *h,
577 int size, int alignment,
578 void *(*chunkfun) (long),
579 void (*freefun) (void *))
581 register struct _obstack_chunk *chunk; /* points to new chunk */
584 alignment = DEFAULT_ALIGNMENT;
586 /* Default size is what GNU malloc can fit in a 4096-byte block. */
588 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
589 Use the values for range checking, because if range checking is off,
590 the extra bytes won't be missed terribly, but if range checking is on
591 and we used a larger request, a whole extra 4096 bytes would be
593 These number are irrelevant to the new GNU malloc. I suspect it is
594 less sensitive to the size of the request. */
595 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
596 + 4 + DEFAULT_ROUNDING - 1)
597 & ~(DEFAULT_ROUNDING - 1));
601 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
602 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
603 h->chunk_size = size;
604 h->alignment_mask = alignment - 1;
605 h->use_extra_arg = 0;
607 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
608 if (!chunk) print_and_abort();
609 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
611 h->chunk_limit = chunk->limit
612 = (char *) chunk + h->chunk_size;
614 /* The initial chunk now contains no empty object. */
615 h->maybe_empty_object = 0;
620 static int _obstack_begin_1 (struct obstack *h, int size, int alignment,
621 void *(*chunkfun) (void *, long),
622 void (*freefun) (void *, void *),
625 register struct _obstack_chunk *chunk; /* points to new chunk */
628 alignment = DEFAULT_ALIGNMENT;
630 /* Default size is what GNU malloc can fit in a 4096-byte block. */
632 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
633 Use the values for range checking, because if range checking is off,
634 the extra bytes won't be missed terribly, but if range checking is on
635 and we used a larger request, a whole extra 4096 bytes would be
637 These number are irrelevant to the new GNU malloc. I suspect it is
638 less sensitive to the size of the request. */
639 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
640 + 4 + DEFAULT_ROUNDING - 1)
641 & ~(DEFAULT_ROUNDING - 1));
645 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
646 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
647 h->chunk_size = size;
648 h->alignment_mask = alignment - 1;
650 h->use_extra_arg = 1;
652 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
653 if (!chunk) print_and_abort();
654 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents,
656 h->chunk_limit = chunk->limit
657 = (char *) chunk + h->chunk_size;
659 /* The initial chunk now contains no empty object. */
660 h->maybe_empty_object = 0;
665 /* Allocate a new current chunk for the obstack *H
666 on the assumption that LENGTH bytes need to be added
667 to the current object, or a new object of length LENGTH allocated.
668 Copies any partial object from the end of the old chunk
669 to the beginning of the new one. */
671 static void _obstack_newchunk (struct obstack *h, int length)
673 register struct _obstack_chunk *old_chunk = h->chunk;
674 register struct _obstack_chunk *new_chunk;
675 register long new_size;
676 register long obj_size = h->next_free - h->object_base;
681 /* Compute size for new chunk. */
682 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
683 if (new_size < h->chunk_size)
684 new_size = h->chunk_size;
686 /* Allocate and initialize the new chunk. */
687 new_chunk = CALL_CHUNKFUN (h, new_size);
688 if (!new_chunk) print_and_abort();
689 h->chunk = new_chunk;
690 new_chunk->prev = old_chunk;
691 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
693 /* Compute an aligned object_base in the new chunk */
695 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask);
697 /* Move the existing object to the new chunk.
698 Word at a time is fast and is safe if the object
699 is sufficiently aligned. */
700 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
702 for (i = obj_size / sizeof (COPYING_UNIT) - 1;
704 ((COPYING_UNIT *)object_base)[i]
705 = ((COPYING_UNIT *)h->object_base)[i];
706 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
707 but that can cross a page boundary on a machine
708 which does not do strict alignment for COPYING_UNITS. */
709 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
713 /* Copy remaining bytes one by one. */
714 for (i = already; i < obj_size; i++)
715 object_base[i] = h->object_base[i];
717 /* If the object just copied was the only data in OLD_CHUNK,
718 free that chunk and remove it from the chain.
719 But not if that chunk might contain an empty object. */
720 if (! h->maybe_empty_object
722 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents,
725 new_chunk->prev = old_chunk->prev;
726 CALL_FREEFUN (h, old_chunk);
729 h->object_base = object_base;
730 h->next_free = h->object_base + obj_size;
731 /* The new chunk certainly contains no empty object yet. */
732 h->maybe_empty_object = 0;
735 /* Return nonzero if object OBJ has been allocated from obstack H.
736 This is here for debugging.
737 If you use it in a program, you are probably losing. */
739 /* Free objects in obstack H, including OBJ and everything allocate
740 more recently than OBJ. If OBJ is zero, free everything in H. */
741 static void obstack_free_func (struct obstack *h, void *obj)
743 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */
744 register struct _obstack_chunk *plp; /* point to previous chunk if any */
747 /* We use >= because there cannot be an object at the beginning of a chunk.
748 But there can be an empty object at that address
749 at the end of another chunk. */
750 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj))
753 CALL_FREEFUN (h, lp);
755 /* If we switch chunks, we can't tell whether the new current
756 chunk contains an empty object, so assume that it may. */
757 h->maybe_empty_object = 1;
761 h->object_base = h->next_free = (char *) (obj);
762 h->chunk_limit = lp->limit;
766 /* obj is not in any of the chunks! */
770 static int _obstack_memory_used (struct obstack *h)
772 register struct _obstack_chunk* lp;
773 register int nbytes = 0;
775 for (lp = h->chunk; lp != 0; lp = lp->prev)
777 nbytes += lp->limit - (char *) lp;
782 static void __attribute__ ((noreturn)) print_and_abort (void)
784 fprintf(stderr, "%s\n", "memory exhausted");
788 /* END LOCAL ADDITION */
794 #endif /* obstack.h */