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9bf86ebb PR |
1 | /* obstack.c - subroutines used implicitly by object stack macros |
2 | Copyright (C) 1988, 1993 Free Software Foundation, Inc. | |
3 | ||
4 | This program is free software; you can redistribute it and/or modify it | |
5 | under the terms of the GNU General Public License as published by the | |
6 | Free Software Foundation; either version 2, or (at your option) any | |
7 | later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
16 | Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
17 | ||
18 | #include "obstack.h" | |
19 | ||
20 | /* This is just to get __GNU_LIBRARY__ defined. */ | |
21 | #include <stdio.h> | |
22 | ||
23 | /* Comment out all this code if we are using the GNU C Library, and are not | |
24 | actually compiling the library itself. This code is part of the GNU C | |
25 | Library, but also included in many other GNU distributions. Compiling | |
26 | and linking in this code is a waste when using the GNU C library | |
27 | (especially if it is a shared library). Rather than having every GNU | |
28 | program understand `configure --with-gnu-libc' and omit the object files, | |
29 | it is simpler to just do this in the source for each such file. */ | |
30 | ||
31 | #if defined (_LIBC) || !defined (__GNU_LIBRARY__) | |
32 | ||
33 | ||
34 | #ifdef __STDC__ | |
35 | #define POINTER void * | |
36 | #else | |
37 | #define POINTER char * | |
38 | #endif | |
39 | ||
40 | /* Determine default alignment. */ | |
41 | struct fooalign {char x; double d;}; | |
42 | #define DEFAULT_ALIGNMENT \ | |
43 | ((PTR_INT_TYPE) ((char *)&((struct fooalign *) 0)->d - (char *)0)) | |
44 | /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. | |
45 | But in fact it might be less smart and round addresses to as much as | |
46 | DEFAULT_ROUNDING. So we prepare for it to do that. */ | |
47 | union fooround {long x; double d;}; | |
48 | #define DEFAULT_ROUNDING (sizeof (union fooround)) | |
49 | ||
50 | /* When we copy a long block of data, this is the unit to do it with. | |
51 | On some machines, copying successive ints does not work; | |
52 | in such a case, redefine COPYING_UNIT to `long' (if that works) | |
53 | or `char' as a last resort. */ | |
54 | #ifndef COPYING_UNIT | |
55 | #define COPYING_UNIT int | |
56 | #endif | |
57 | ||
58 | /* The non-GNU-C macros copy the obstack into this global variable | |
59 | to avoid multiple evaluation. */ | |
60 | ||
61 | struct obstack *_obstack; | |
62 | ||
63 | /* Define a macro that either calls functions with the traditional malloc/free | |
64 | calling interface, or calls functions with the mmalloc/mfree interface | |
65 | (that adds an extra first argument), based on the state of use_extra_arg. | |
66 | For free, do not use ?:, since some compilers, like the MIPS compilers, | |
67 | do not allow (expr) ? void : void. */ | |
68 | ||
69 | #define CALL_CHUNKFUN(h, size) \ | |
70 | (((h) -> use_extra_arg) \ | |
71 | ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \ | |
72 | : (*(h)->chunkfun) ((size))) | |
73 | ||
74 | #define CALL_FREEFUN(h, old_chunk) \ | |
75 | do { \ | |
76 | if ((h) -> use_extra_arg) \ | |
77 | (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \ | |
78 | else \ | |
79 | (*(h)->freefun) ((old_chunk)); \ | |
80 | } while (0) | |
81 | ||
82 | \f | |
83 | /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default). | |
84 | Objects start on multiples of ALIGNMENT (0 means use default). | |
85 | CHUNKFUN is the function to use to allocate chunks, | |
86 | and FREEFUN the function to free them. */ | |
87 | ||
88 | void | |
89 | _obstack_begin (h, size, alignment, chunkfun, freefun) | |
90 | struct obstack *h; | |
91 | int size; | |
92 | int alignment; | |
93 | POINTER (*chunkfun) (); | |
94 | void (*freefun) (); | |
95 | { | |
96 | register struct _obstack_chunk* chunk; /* points to new chunk */ | |
97 | ||
98 | if (alignment == 0) | |
99 | alignment = DEFAULT_ALIGNMENT; | |
100 | if (size == 0) | |
101 | /* Default size is what GNU malloc can fit in a 4096-byte block. */ | |
102 | { | |
103 | /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. | |
104 | Use the values for range checking, because if range checking is off, | |
105 | the extra bytes won't be missed terribly, but if range checking is on | |
106 | and we used a larger request, a whole extra 4096 bytes would be | |
107 | allocated. | |
108 | ||
109 | These number are irrelevant to the new GNU malloc. I suspect it is | |
110 | less sensitive to the size of the request. */ | |
111 | int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) | |
112 | + 4 + DEFAULT_ROUNDING - 1) | |
113 | & ~(DEFAULT_ROUNDING - 1)); | |
114 | size = 4096 - extra; | |
115 | } | |
116 | ||
117 | h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun; | |
118 | h->freefun = freefun; | |
119 | h->chunk_size = size; | |
120 | h->alignment_mask = alignment - 1; | |
121 | h->use_extra_arg = 0; | |
122 | ||
123 | chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); | |
124 | h->next_free = h->object_base = chunk->contents; | |
125 | h->chunk_limit = chunk->limit | |
126 | = (char *) chunk + h->chunk_size; | |
127 | chunk->prev = 0; | |
128 | /* The initial chunk now contains no empty object. */ | |
129 | h->maybe_empty_object = 0; | |
130 | } | |
131 | ||
132 | void | |
133 | _obstack_begin_1 (h, size, alignment, chunkfun, freefun, arg) | |
134 | struct obstack *h; | |
135 | int size; | |
136 | int alignment; | |
137 | POINTER (*chunkfun) (); | |
138 | void (*freefun) (); | |
139 | POINTER arg; | |
140 | { | |
141 | register struct _obstack_chunk* chunk; /* points to new chunk */ | |
142 | ||
143 | if (alignment == 0) | |
144 | alignment = DEFAULT_ALIGNMENT; | |
145 | if (size == 0) | |
146 | /* Default size is what GNU malloc can fit in a 4096-byte block. */ | |
147 | { | |
148 | /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. | |
149 | Use the values for range checking, because if range checking is off, | |
150 | the extra bytes won't be missed terribly, but if range checking is on | |
151 | and we used a larger request, a whole extra 4096 bytes would be | |
152 | allocated. | |
153 | ||
154 | These number are irrelevant to the new GNU malloc. I suspect it is | |
155 | less sensitive to the size of the request. */ | |
156 | int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) | |
157 | + 4 + DEFAULT_ROUNDING - 1) | |
158 | & ~(DEFAULT_ROUNDING - 1)); | |
159 | size = 4096 - extra; | |
160 | } | |
161 | ||
162 | h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun; | |
163 | h->freefun = freefun; | |
164 | h->chunk_size = size; | |
165 | h->alignment_mask = alignment - 1; | |
166 | h->extra_arg = arg; | |
167 | h->use_extra_arg = 1; | |
168 | ||
169 | chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); | |
170 | h->next_free = h->object_base = chunk->contents; | |
171 | h->chunk_limit = chunk->limit | |
172 | = (char *) chunk + h->chunk_size; | |
173 | chunk->prev = 0; | |
174 | /* The initial chunk now contains no empty object. */ | |
175 | h->maybe_empty_object = 0; | |
176 | } | |
177 | ||
178 | /* Allocate a new current chunk for the obstack *H | |
179 | on the assumption that LENGTH bytes need to be added | |
180 | to the current object, or a new object of length LENGTH allocated. | |
181 | Copies any partial object from the end of the old chunk | |
182 | to the beginning of the new one. */ | |
183 | ||
184 | void | |
185 | _obstack_newchunk (h, length) | |
186 | struct obstack *h; | |
187 | int length; | |
188 | { | |
189 | register struct _obstack_chunk* old_chunk = h->chunk; | |
190 | register struct _obstack_chunk* new_chunk; | |
191 | register long new_size; | |
192 | register int obj_size = h->next_free - h->object_base; | |
193 | register int i; | |
194 | int already; | |
195 | ||
196 | /* Compute size for new chunk. */ | |
197 | new_size = (obj_size + length) + (obj_size >> 3) + 100; | |
198 | if (new_size < h->chunk_size) | |
199 | new_size = h->chunk_size; | |
200 | ||
201 | /* Allocate and initialize the new chunk. */ | |
202 | new_chunk = h->chunk = CALL_CHUNKFUN (h, new_size); | |
203 | new_chunk->prev = old_chunk; | |
204 | new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; | |
205 | ||
206 | /* Move the existing object to the new chunk. | |
207 | Word at a time is fast and is safe if the object | |
208 | is sufficiently aligned. */ | |
209 | if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT) | |
210 | { | |
211 | for (i = obj_size / sizeof (COPYING_UNIT) - 1; | |
212 | i >= 0; i--) | |
213 | ((COPYING_UNIT *)new_chunk->contents)[i] | |
214 | = ((COPYING_UNIT *)h->object_base)[i]; | |
215 | /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT, | |
216 | but that can cross a page boundary on a machine | |
217 | which does not do strict alignment for COPYING_UNITS. */ | |
218 | already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT); | |
219 | } | |
220 | else | |
221 | already = 0; | |
222 | /* Copy remaining bytes one by one. */ | |
223 | for (i = already; i < obj_size; i++) | |
224 | new_chunk->contents[i] = h->object_base[i]; | |
225 | ||
226 | /* If the object just copied was the only data in OLD_CHUNK, | |
227 | free that chunk and remove it from the chain. | |
228 | But not if that chunk might contain an empty object. */ | |
229 | if (h->object_base == old_chunk->contents && ! h->maybe_empty_object) | |
230 | { | |
231 | new_chunk->prev = old_chunk->prev; | |
232 | CALL_FREEFUN (h, old_chunk); | |
233 | } | |
234 | ||
235 | h->object_base = new_chunk->contents; | |
236 | h->next_free = h->object_base + obj_size; | |
237 | /* The new chunk certainly contains no empty object yet. */ | |
238 | h->maybe_empty_object = 0; | |
239 | } | |
240 | ||
241 | /* Return nonzero if object OBJ has been allocated from obstack H. | |
242 | This is here for debugging. | |
243 | If you use it in a program, you are probably losing. */ | |
244 | ||
245 | int | |
246 | _obstack_allocated_p (h, obj) | |
247 | struct obstack *h; | |
248 | POINTER obj; | |
249 | { | |
250 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ | |
251 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ | |
252 | ||
253 | lp = (h)->chunk; | |
254 | /* We use >= rather than > since the object cannot be exactly at | |
255 | the beginning of the chunk but might be an empty object exactly | |
256 | at the end of an adjacent chunk. */ | |
257 | while (lp != 0 && ((POINTER)lp >= obj || (POINTER)(lp)->limit < obj)) | |
258 | { | |
259 | plp = lp->prev; | |
260 | lp = plp; | |
261 | } | |
262 | return lp != 0; | |
263 | } | |
264 | \f | |
265 | /* Free objects in obstack H, including OBJ and everything allocate | |
266 | more recently than OBJ. If OBJ is zero, free everything in H. */ | |
267 | ||
268 | #undef obstack_free | |
269 | ||
270 | /* This function has two names with identical definitions. | |
271 | This is the first one, called from non-ANSI code. */ | |
272 | ||
273 | void | |
274 | _obstack_free (h, obj) | |
275 | struct obstack *h; | |
276 | POINTER obj; | |
277 | { | |
278 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ | |
279 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ | |
280 | ||
281 | lp = h->chunk; | |
282 | /* We use >= because there cannot be an object at the beginning of a chunk. | |
283 | But there can be an empty object at that address | |
284 | at the end of another chunk. */ | |
285 | while (lp != 0 && ((POINTER)lp >= obj || (POINTER)(lp)->limit < obj)) | |
286 | { | |
287 | plp = lp->prev; | |
288 | CALL_FREEFUN (h, lp); | |
289 | lp = plp; | |
290 | /* If we switch chunks, we can't tell whether the new current | |
291 | chunk contains an empty object, so assume that it may. */ | |
292 | h->maybe_empty_object = 1; | |
293 | } | |
294 | if (lp) | |
295 | { | |
296 | h->object_base = h->next_free = (char *)(obj); | |
297 | h->chunk_limit = lp->limit; | |
298 | h->chunk = lp; | |
299 | } | |
300 | else if (obj != 0) | |
301 | /* obj is not in any of the chunks! */ | |
302 | abort (); | |
303 | } | |
304 | ||
305 | /* This function is used from ANSI code. */ | |
306 | ||
307 | void | |
308 | obstack_free (h, obj) | |
309 | struct obstack *h; | |
310 | POINTER obj; | |
311 | { | |
312 | register struct _obstack_chunk* lp; /* below addr of any objects in this chunk */ | |
313 | register struct _obstack_chunk* plp; /* point to previous chunk if any */ | |
314 | ||
315 | lp = h->chunk; | |
316 | /* We use >= because there cannot be an object at the beginning of a chunk. | |
317 | But there can be an empty object at that address | |
318 | at the end of another chunk. */ | |
319 | while (lp != 0 && ((POINTER)lp >= obj || (POINTER)(lp)->limit < obj)) | |
320 | { | |
321 | plp = lp->prev; | |
322 | CALL_FREEFUN (h, lp); | |
323 | lp = plp; | |
324 | /* If we switch chunks, we can't tell whether the new current | |
325 | chunk contains an empty object, so assume that it may. */ | |
326 | h->maybe_empty_object = 1; | |
327 | } | |
328 | if (lp) | |
329 | { | |
330 | h->object_base = h->next_free = (char *)(obj); | |
331 | h->chunk_limit = lp->limit; | |
332 | h->chunk = lp; | |
333 | } | |
334 | else if (obj != 0) | |
335 | /* obj is not in any of the chunks! */ | |
336 | abort (); | |
337 | } | |
338 | \f | |
339 | #if 0 | |
340 | /* These are now turned off because the applications do not use it | |
341 | and it uses bcopy via obstack_grow, which causes trouble on sysV. */ | |
342 | ||
343 | /* Now define the functional versions of the obstack macros. | |
344 | Define them to simply use the corresponding macros to do the job. */ | |
345 | ||
346 | #ifdef __STDC__ | |
347 | /* These function definitions do not work with non-ANSI preprocessors; | |
348 | they won't pass through the macro names in parentheses. */ | |
349 | ||
350 | /* The function names appear in parentheses in order to prevent | |
351 | the macro-definitions of the names from being expanded there. */ | |
352 | ||
353 | POINTER (obstack_base) (obstack) | |
354 | struct obstack *obstack; | |
355 | { | |
356 | return obstack_base (obstack); | |
357 | } | |
358 | ||
359 | POINTER (obstack_next_free) (obstack) | |
360 | struct obstack *obstack; | |
361 | { | |
362 | return obstack_next_free (obstack); | |
363 | } | |
364 | ||
365 | int (obstack_object_size) (obstack) | |
366 | struct obstack *obstack; | |
367 | { | |
368 | return obstack_object_size (obstack); | |
369 | } | |
370 | ||
371 | int (obstack_room) (obstack) | |
372 | struct obstack *obstack; | |
373 | { | |
374 | return obstack_room (obstack); | |
375 | } | |
376 | ||
377 | void (obstack_grow) (obstack, pointer, length) | |
378 | struct obstack *obstack; | |
379 | POINTER pointer; | |
380 | int length; | |
381 | { | |
382 | obstack_grow (obstack, pointer, length); | |
383 | } | |
384 | ||
385 | void (obstack_grow0) (obstack, pointer, length) | |
386 | struct obstack *obstack; | |
387 | POINTER pointer; | |
388 | int length; | |
389 | { | |
390 | obstack_grow0 (obstack, pointer, length); | |
391 | } | |
392 | ||
393 | void (obstack_1grow) (obstack, character) | |
394 | struct obstack *obstack; | |
395 | int character; | |
396 | { | |
397 | obstack_1grow (obstack, character); | |
398 | } | |
399 | ||
400 | void (obstack_blank) (obstack, length) | |
401 | struct obstack *obstack; | |
402 | int length; | |
403 | { | |
404 | obstack_blank (obstack, length); | |
405 | } | |
406 | ||
407 | void (obstack_1grow_fast) (obstack, character) | |
408 | struct obstack *obstack; | |
409 | int character; | |
410 | { | |
411 | obstack_1grow_fast (obstack, character); | |
412 | } | |
413 | ||
414 | void (obstack_blank_fast) (obstack, length) | |
415 | struct obstack *obstack; | |
416 | int length; | |
417 | { | |
418 | obstack_blank_fast (obstack, length); | |
419 | } | |
420 | ||
421 | POINTER (obstack_finish) (obstack) | |
422 | struct obstack *obstack; | |
423 | { | |
424 | return obstack_finish (obstack); | |
425 | } | |
426 | ||
427 | POINTER (obstack_alloc) (obstack, length) | |
428 | struct obstack *obstack; | |
429 | int length; | |
430 | { | |
431 | return obstack_alloc (obstack, length); | |
432 | } | |
433 | ||
434 | POINTER (obstack_copy) (obstack, pointer, length) | |
435 | struct obstack *obstack; | |
436 | POINTER pointer; | |
437 | int length; | |
438 | { | |
439 | return obstack_copy (obstack, pointer, length); | |
440 | } | |
441 | ||
442 | POINTER (obstack_copy0) (obstack, pointer, length) | |
443 | struct obstack *obstack; | |
444 | POINTER pointer; | |
445 | int length; | |
446 | { | |
447 | return obstack_copy0 (obstack, pointer, length); | |
448 | } | |
449 | ||
450 | #endif /* __STDC__ */ | |
451 | ||
452 | #endif /* 0 */ | |
453 | ||
454 | #endif /* _LIBC or not __GNU_LIBRARY__. */ |