1 /* obstack.c - subroutines used implicitly by object stack macros 2 3 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997, 4 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software 5 Foundation, Inc. 6 7 This program is free software: you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program 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 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #ifdef _LIBC 21 # include <obstack.h> 22 # include <shlib-compat.h> 23 #else 24 # include <config.h> 25 # include "obstack.h" 26 #endif 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 #include <stddef.h> 51 52 #ifndef ELIDE_CODE 53 54 # include <stdint.h> 55 56 /* Determine default alignment. */ 57 union fooround 58 { 59 uintmax_t i; 60 long double d; 61 void *p; 62 }; 63 struct fooalign 64 { 65 char c; 66 union fooround u; 67 }; 68 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. 69 But in fact it might be less smart and round addresses to as much as 70 DEFAULT_ROUNDING. So we prepare for it to do that. */ 71 enum 72 { 73 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u), 74 DEFAULT_ROUNDING = sizeof (union fooround) 75 }; 76 77 /* When we copy a long block of data, this is the unit to do it with. 78 On some machines, copying successive ints does not work; 79 in such a case, redefine COPYING_UNIT to `long' (if that works) 80 or `char' as a last resort. */ 81 # ifndef COPYING_UNIT 82 # define COPYING_UNIT int 83 # endif 84 85 86 /* The functions allocating more room by calling `obstack_chunk_alloc' 87 jump to the handler pointed to by `obstack_alloc_failed_handler'. 88 This can be set to a user defined function which should either 89 abort gracefully or use longjump - but shouldn't return. This 90 variable by default points to the internal function 91 `print_and_abort'. */ 92 static void print_and_abort (void); 93 void (*obstack_alloc_failed_handler) (void) = print_and_abort; 94 95 /* Exit value used when `print_and_abort' is used. */ 96 # include <stdlib.h> 97 # ifdef _LIBC 98 int obstack_exit_failure = EXIT_FAILURE; 99 # else 100 # include "exitfail.h" 101 # define obstack_exit_failure exit_failure 102 # endif 103 104 # ifdef _LIBC 105 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4) 106 /* A looong time ago (before 1994, anyway; we're not sure) this global variable 107 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C 108 library still exports it because somebody might use it. */ 109 struct obstack *_obstack_compat; 110 compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0); 111 # endif 112 # endif 113 114 /* Define a macro that either calls functions with the traditional malloc/free 115 calling interface, or calls functions with the mmalloc/mfree interface 116 (that adds an extra first argument), based on the state of use_extra_arg. 117 For free, do not use ?:, since some compilers, like the MIPS compilers, 118 do not allow (expr) ? void : void. */ 119 120 # define CALL_CHUNKFUN(h, size) \ 121 (((h) -> use_extra_arg) \ 122 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \ 123 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size))) 124 125 # define CALL_FREEFUN(h, old_chunk) \ 126 do { \ 127 if ((h) -> use_extra_arg) \ 128 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \ 129 else \ 130 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \ 131 } while (0) 132 133 134 /* Initialize an obstack H for use. Specify chunk size SIZE (0 means default). 136 Objects start on multiples of ALIGNMENT (0 means use default). 137 CHUNKFUN is the function to use to allocate chunks, 138 and FREEFUN the function to free them. 139 140 Return nonzero if successful, calls obstack_alloc_failed_handler if 141 allocation fails. */ 142 143 int 144 _obstack_begin (struct obstack *h, 145 int size, int alignment, 146 void *(*chunkfun) (long), 147 void (*freefun) (void *)) 148 { 149 register struct _obstack_chunk *chunk; /* points to new chunk */ 150 151 if (alignment == 0) 152 alignment = DEFAULT_ALIGNMENT; 153 if (size == 0) 154 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 155 { 156 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 157 Use the values for range checking, because if range checking is off, 158 the extra bytes won't be missed terribly, but if range checking is on 159 and we used a larger request, a whole extra 4096 bytes would be 160 allocated. 161 162 These number are irrelevant to the new GNU malloc. I suspect it is 163 less sensitive to the size of the request. */ 164 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 165 + 4 + DEFAULT_ROUNDING - 1) 166 & ~(DEFAULT_ROUNDING - 1)); 167 size = 4096 - extra; 168 } 169 170 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun; 171 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 172 h->chunk_size = size; 173 h->alignment_mask = alignment - 1; 174 h->use_extra_arg = 0; 175 176 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 177 if (!chunk) 178 (*obstack_alloc_failed_handler) (); 179 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 180 alignment - 1); 181 h->chunk_limit = chunk->limit 182 = (char *) chunk + h->chunk_size; 183 chunk->prev = 0; 184 /* The initial chunk now contains no empty object. */ 185 h->maybe_empty_object = 0; 186 h->alloc_failed = 0; 187 return 1; 188 } 189 190 int 191 _obstack_begin_1 (struct obstack *h, int size, int alignment, 192 void *(*chunkfun) (void *, long), 193 void (*freefun) (void *, void *), 194 void *arg) 195 { 196 register struct _obstack_chunk *chunk; /* points to new chunk */ 197 198 if (alignment == 0) 199 alignment = DEFAULT_ALIGNMENT; 200 if (size == 0) 201 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 202 { 203 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 204 Use the values for range checking, because if range checking is off, 205 the extra bytes won't be missed terribly, but if range checking is on 206 and we used a larger request, a whole extra 4096 bytes would be 207 allocated. 208 209 These number are irrelevant to the new GNU malloc. I suspect it is 210 less sensitive to the size of the request. */ 211 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 212 + 4 + DEFAULT_ROUNDING - 1) 213 & ~(DEFAULT_ROUNDING - 1)); 214 size = 4096 - extra; 215 } 216 217 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun; 218 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 219 h->chunk_size = size; 220 h->alignment_mask = alignment - 1; 221 h->extra_arg = arg; 222 h->use_extra_arg = 1; 223 224 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 225 if (!chunk) 226 (*obstack_alloc_failed_handler) (); 227 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 228 alignment - 1); 229 h->chunk_limit = chunk->limit 230 = (char *) chunk + h->chunk_size; 231 chunk->prev = 0; 232 /* The initial chunk now contains no empty object. */ 233 h->maybe_empty_object = 0; 234 h->alloc_failed = 0; 235 return 1; 236 } 237 238 /* Allocate a new current chunk for the obstack *H 239 on the assumption that LENGTH bytes need to be added 240 to the current object, or a new object of length LENGTH allocated. 241 Copies any partial object from the end of the old chunk 242 to the beginning of the new one. */ 243 244 void 245 _obstack_newchunk (struct obstack *h, int length) 246 { 247 register struct _obstack_chunk *old_chunk = h->chunk; 248 register struct _obstack_chunk *new_chunk; 249 register long new_size; 250 register long obj_size = h->next_free - h->object_base; 251 register long i; 252 long already; 253 char *object_base; 254 255 /* Compute size for new chunk. */ 256 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100; 257 if (new_size < h->chunk_size) 258 new_size = h->chunk_size; 259 260 /* Allocate and initialize the new chunk. */ 261 new_chunk = CALL_CHUNKFUN (h, new_size); 262 if (!new_chunk) 263 (*obstack_alloc_failed_handler) (); 264 h->chunk = new_chunk; 265 new_chunk->prev = old_chunk; 266 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; 267 268 /* Compute an aligned object_base in the new chunk */ 269 object_base = 270 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask); 271 272 /* Move the existing object to the new chunk. 273 Word at a time is fast and is safe if the object 274 is sufficiently aligned. */ 275 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT) 276 { 277 for (i = obj_size / sizeof (COPYING_UNIT) - 1; 278 i >= 0; i--) 279 ((COPYING_UNIT *)object_base)[i] 280 = ((COPYING_UNIT *)h->object_base)[i]; 281 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT, 282 but that can cross a page boundary on a machine 283 which does not do strict alignment for COPYING_UNITS. */ 284 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT); 285 } 286 else 287 already = 0; 288 /* Copy remaining bytes one by one. */ 289 for (i = already; i < obj_size; i++) 290 object_base[i] = h->object_base[i]; 291 292 /* If the object just copied was the only data in OLD_CHUNK, 293 free that chunk and remove it from the chain. 294 But not if that chunk might contain an empty object. */ 295 if (! h->maybe_empty_object 296 && (h->object_base 297 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents, 298 h->alignment_mask))) 299 { 300 new_chunk->prev = old_chunk->prev; 301 CALL_FREEFUN (h, old_chunk); 302 } 303 304 h->object_base = object_base; 305 h->next_free = h->object_base + obj_size; 306 /* The new chunk certainly contains no empty object yet. */ 307 h->maybe_empty_object = 0; 308 } 309 # ifdef _LIBC 310 libc_hidden_def (_obstack_newchunk) 311 # endif 312 313 /* Return nonzero if object OBJ has been allocated from obstack H. 314 This is here for debugging. 315 If you use it in a program, you are probably losing. */ 316 317 /* Suppress -Wmissing-prototypes warning. We don't want to declare this in 318 obstack.h because it is just for debugging. */ 319 int _obstack_allocated_p (struct obstack *h, void *obj); 320 321 int 322 _obstack_allocated_p (struct obstack *h, void *obj) 323 { 324 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 325 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 326 327 lp = (h)->chunk; 328 /* We use >= rather than > since the object cannot be exactly at 329 the beginning of the chunk but might be an empty object exactly 330 at the end of an adjacent chunk. */ 331 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 332 { 333 plp = lp->prev; 334 lp = plp; 335 } 336 return lp != 0; 337 } 338 339 /* Free objects in obstack H, including OBJ and everything allocate 341 more recently than OBJ. If OBJ is zero, free everything in H. */ 342 343 # undef obstack_free 344 345 void 346 __obstack_free (struct obstack *h, void *obj) 347 { 348 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 349 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 350 351 lp = h->chunk; 352 /* We use >= because there cannot be an object at the beginning of a chunk. 353 But there can be an empty object at that address 354 at the end of another chunk. */ 355 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 356 { 357 plp = lp->prev; 358 CALL_FREEFUN (h, lp); 359 lp = plp; 360 /* If we switch chunks, we can't tell whether the new current 361 chunk contains an empty object, so assume that it may. */ 362 h->maybe_empty_object = 1; 363 } 364 if (lp) 365 { 366 h->object_base = h->next_free = (char *) (obj); 367 h->chunk_limit = lp->limit; 368 h->chunk = lp; 369 } 370 else if (obj != 0) 371 /* obj is not in any of the chunks! */ 372 abort (); 373 } 374 375 # ifdef _LIBC 376 /* Older versions of libc used a function _obstack_free intended to be 377 called by non-GCC compilers. */ 378 strong_alias (obstack_free, _obstack_free) 379 # endif 380 381 int 383 _obstack_memory_used (struct obstack *h) 384 { 385 register struct _obstack_chunk* lp; 386 register int nbytes = 0; 387 388 for (lp = h->chunk; lp != 0; lp = lp->prev) 389 { 390 nbytes += lp->limit - (char *) lp; 391 } 392 return nbytes; 393 } 394 395 /* Define the error handler. */ 397 # ifdef _LIBC 398 # include <libintl.h> 399 # else 400 # include "gettext.h" 401 # endif 402 # ifndef _ 403 # define _(msgid) gettext (msgid) 404 # endif 405 406 # ifdef _LIBC 407 # include <libio/iolibio.h> 408 # endif 409 410 # ifndef __attribute__ 411 /* This feature is available in gcc versions 2.5 and later. */ 412 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) 413 # define __attribute__(Spec) /* empty */ 414 # endif 415 # endif 416 417 static void 418 __attribute__ ((noreturn)) 419 print_and_abort (void) 420 { 421 /* Don't change any of these strings. Yes, it would be possible to add 422 the newline to the string and use fputs or so. But this must not 423 happen because the "memory exhausted" message appears in other places 424 like this and the translation should be reused instead of creating 425 a very similar string which requires a separate translation. */ 426 # ifdef _LIBC 427 (void) __fxprintf (NULL, "%s\n", _("memory exhausted")); 428 # else 429 fprintf (stderr, "%s\n", _("memory exhausted")); 430 # endif 431 exit (obstack_exit_failure); 432 } 433 434 #endif /* !ELIDE_CODE */ 435
