1/* obstack.c - subroutines used implicitly by object stack macros 2 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 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. 10 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. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 Boston, MA 02110-1301, USA. */ 20 21 22#ifdef HAVE_CONFIG_H 23# include <config.h> 24#endif 25 26#ifdef _LIBC 27# include <obstack.h> 28# include <shlib-compat.h> 29#else 30# include "obstack.h" 31#endif 32 33/* NOTE BEFORE MODIFYING THIS FILE: This version number must be 34 incremented whenever callers compiled using an old obstack.h can no 35 longer properly call the functions in this obstack.c. */ 36#define OBSTACK_INTERFACE_VERSION 1 37 38/* Comment out all this code if we are using the GNU C Library, and are not 39 actually compiling the library itself, and the installed library 40 supports the same library interface we do. This code is part of the GNU 41 C Library, but also included in many other GNU distributions. Compiling 42 and linking in this code is a waste when using the GNU C library 43 (especially if it is a shared library). Rather than having every GNU 44 program understand `configure --with-gnu-libc' and omit the object 45 files, it is simpler to just do this in the source for each such file. */ 46 47#include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */ 48#if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1 49# include <gnu-versions.h> 50# if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION 51# define ELIDE_CODE 52# endif 53#endif 54 55#include <stddef.h> 56 57#ifndef ELIDE_CODE 58 59 60# if HAVE_INTTYPES_H 61# include <inttypes.h> 62# endif 63# if HAVE_STDINT_H || defined _LIBC 64# include <stdint.h> 65# endif 66 67/* Determine default alignment. */ 68union fooround 69{ 70 uintmax_t i; 71 long double d; 72 void *p; 73}; 74struct fooalign 75{ 76 char c; 77 union fooround u; 78}; 79/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. 80 But in fact it might be less smart and round addresses to as much as 81 DEFAULT_ROUNDING. So we prepare for it to do that. */ 82enum 83 { 84 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u), 85 DEFAULT_ROUNDING = sizeof (union fooround) 86 }; 87 88/* When we copy a long block of data, this is the unit to do it with. 89 On some machines, copying successive ints does not work; 90 in such a case, redefine COPYING_UNIT to `long' (if that works) 91 or `char' as a last resort. */ 92# ifndef COPYING_UNIT 93# define COPYING_UNIT int 94# endif 95 96 97/* The functions allocating more room by calling `obstack_chunk_alloc' 98 jump to the handler pointed to by `obstack_alloc_failed_handler'. 99 This can be set to a user defined function which should either 100 abort gracefully or use longjump - but shouldn't return. This 101 variable by default points to the internal function 102 `print_and_abort'. */ 103static void print_and_abort (void); 104void (*obstack_alloc_failed_handler) (void) = print_and_abort; 105 106/* Exit value used when `print_and_abort' is used. */ 107# include <stdlib.h> 108# ifdef _LIBC 109int obstack_exit_failure = EXIT_FAILURE; 110# else 111# include "exitfail.h" 112# define obstack_exit_failure exit_failure 113# endif 114 115# ifdef _LIBC 116# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4) 117/* A looong time ago (before 1994, anyway; we're not sure) this global variable 118 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C 119 library still exports it because somebody might use it. */ 120struct obstack *_obstack_compat; 121compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0); 122# endif 123# endif 124 125/* Define a macro that either calls functions with the traditional malloc/free 126 calling interface, or calls functions with the mmalloc/mfree interface 127 (that adds an extra first argument), based on the state of use_extra_arg. 128 For free, do not use ?:, since some compilers, like the MIPS compilers, 129 do not allow (expr) ? void : void. */ 130 131# define CALL_CHUNKFUN(h, size) \ 132 (((h) -> use_extra_arg) \ 133 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \ 134 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size))) 135 136# define CALL_FREEFUN(h, old_chunk) \ 137 do { \ 138 if ((h) -> use_extra_arg) \ 139 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \ 140 else \ 141 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \ 142 } while (0) 143 144\f 145/* Initialize an obstack H for use. Specify chunk size SIZE (0 means default). 146 Objects start on multiples of ALIGNMENT (0 means use default). 147 CHUNKFUN is the function to use to allocate chunks, 148 and FREEFUN the function to free them. 149 150 Return nonzero if successful, calls obstack_alloc_failed_handler if 151 allocation fails. */ 152 153int 154_obstack_begin (struct obstack *h, 155 int size, int alignment, 156 void *(*chunkfun) (long), 157 void (*freefun) (void *)) 158{ 159 register struct _obstack_chunk *chunk; /* points to new chunk */ 160 161 if (alignment == 0) 162 alignment = DEFAULT_ALIGNMENT; 163 if (size == 0) 164 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 165 { 166 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 167 Use the values for range checking, because if range checking is off, 168 the extra bytes won't be missed terribly, but if range checking is on 169 and we used a larger request, a whole extra 4096 bytes would be 170 allocated. 171 172 These number are irrelevant to the new GNU malloc. I suspect it is 173 less sensitive to the size of the request. */ 174 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 175 + 4 + DEFAULT_ROUNDING - 1) 176 & ~(DEFAULT_ROUNDING - 1)); 177 size = 4096 - extra; 178 } 179 180 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun; 181 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 182 h->chunk_size = size; 183 h->alignment_mask = alignment - 1; 184 h->use_extra_arg = 0; 185 186 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 187 if (!chunk) 188 (*obstack_alloc_failed_handler) (); 189 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 190 alignment - 1); 191 h->chunk_limit = chunk->limit 192 = (char *) chunk + h->chunk_size; 193 chunk->prev = 0; 194 /* The initial chunk now contains no empty object. */ 195 h->maybe_empty_object = 0; 196 h->alloc_failed = 0; 197 return 1; 198} 199 200int 201_obstack_begin_1 (struct obstack *h, int size, int alignment, 202 void *(*chunkfun) (void *, long), 203 void (*freefun) (void *, void *), 204 void *arg) 205{ 206 register struct _obstack_chunk *chunk; /* points to new chunk */ 207 208 if (alignment == 0) 209 alignment = DEFAULT_ALIGNMENT; 210 if (size == 0) 211 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 212 { 213 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 214 Use the values for range checking, because if range checking is off, 215 the extra bytes won't be missed terribly, but if range checking is on 216 and we used a larger request, a whole extra 4096 bytes would be 217 allocated. 218 219 These number are irrelevant to the new GNU malloc. I suspect it is 220 less sensitive to the size of the request. */ 221 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 222 + 4 + DEFAULT_ROUNDING - 1) 223 & ~(DEFAULT_ROUNDING - 1)); 224 size = 4096 - extra; 225 } 226 227 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun; 228 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 229 h->chunk_size = size; 230 h->alignment_mask = alignment - 1; 231 h->extra_arg = arg; 232 h->use_extra_arg = 1; 233 234 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 235 if (!chunk) 236 (*obstack_alloc_failed_handler) (); 237 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 238 alignment - 1); 239 h->chunk_limit = chunk->limit 240 = (char *) chunk + h->chunk_size; 241 chunk->prev = 0; 242 /* The initial chunk now contains no empty object. */ 243 h->maybe_empty_object = 0; 244 h->alloc_failed = 0; 245 return 1; 246} 247 248/* Allocate a new current chunk for the obstack *H 249 on the assumption that LENGTH bytes need to be added 250 to the current object, or a new object of length LENGTH allocated. 251 Copies any partial object from the end of the old chunk 252 to the beginning of the new one. */ 253 254void 255_obstack_newchunk (struct obstack *h, int length) 256{ 257 register struct _obstack_chunk *old_chunk = h->chunk; 258 register struct _obstack_chunk *new_chunk; 259 register long new_size; 260 register long obj_size = h->next_free - h->object_base; 261 register long i; 262 long already; 263 char *object_base; 264 265 /* Compute size for new chunk. */ 266 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100; 267 if (new_size < h->chunk_size) 268 new_size = h->chunk_size; 269 270 /* Allocate and initialize the new chunk. */ 271 new_chunk = CALL_CHUNKFUN (h, new_size); 272 if (!new_chunk) 273 (*obstack_alloc_failed_handler) (); 274 h->chunk = new_chunk; 275 new_chunk->prev = old_chunk; 276 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; 277 278 /* Compute an aligned object_base in the new chunk */ 279 object_base = 280 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask); 281 282 /* Move the existing object to the new chunk. 283 Word at a time is fast and is safe if the object 284 is sufficiently aligned. */ 285 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT) 286 { 287 for (i = obj_size / sizeof (COPYING_UNIT) - 1; 288 i >= 0; i--) 289 ((COPYING_UNIT *)object_base)[i] 290 = ((COPYING_UNIT *)h->object_base)[i]; 291 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT, 292 but that can cross a page boundary on a machine 293 which does not do strict alignment for COPYING_UNITS. */ 294 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT); 295 } 296 else 297 already = 0; 298 /* Copy remaining bytes one by one. */ 299 for (i = already; i < obj_size; i++) 300 object_base[i] = h->object_base[i]; 301 302 /* If the object just copied was the only data in OLD_CHUNK, 303 free that chunk and remove it from the chain. 304 But not if that chunk might contain an empty object. */ 305 if (! h->maybe_empty_object 306 && (h->object_base 307 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents, 308 h->alignment_mask))) 309 { 310 new_chunk->prev = old_chunk->prev; 311 CALL_FREEFUN (h, old_chunk); 312 } 313 314 h->object_base = object_base; 315 h->next_free = h->object_base + obj_size; 316 /* The new chunk certainly contains no empty object yet. */ 317 h->maybe_empty_object = 0; 318} 319# ifdef _LIBC 320libc_hidden_def (_obstack_newchunk) 321# endif 322 323/* Return nonzero if object OBJ has been allocated from obstack H. 324 This is here for debugging. 325 If you use it in a program, you are probably losing. */ 326 327/* Suppress -Wmissing-prototypes warning. We don't want to declare this in 328 obstack.h because it is just for debugging. */ 329int _obstack_allocated_p (struct obstack *h, void *obj); 330 331int 332_obstack_allocated_p (struct obstack *h, void *obj) 333{ 334 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 335 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 336 337 lp = (h)->chunk; 338 /* We use >= rather than > since the object cannot be exactly at 339 the beginning of the chunk but might be an empty object exactly 340 at the end of an adjacent chunk. */ 341 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 342 { 343 plp = lp->prev; 344 lp = plp; 345 } 346 return lp != 0; 347} 348\f 349/* Free objects in obstack H, including OBJ and everything allocate 350 more recently than OBJ. If OBJ is zero, free everything in H. */ 351 352# undef obstack_free 353 354void 355obstack_free (struct obstack *h, void *obj) 356{ 357 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 358 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 359 360 lp = h->chunk; 361 /* We use >= because there cannot be an object at the beginning of a chunk. 362 But there can be an empty object at that address 363 at the end of another chunk. */ 364 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 365 { 366 plp = lp->prev; 367 CALL_FREEFUN (h, lp); 368 lp = plp; 369 /* If we switch chunks, we can't tell whether the new current 370 chunk contains an empty object, so assume that it may. */ 371 h->maybe_empty_object = 1; 372 } 373 if (lp) 374 { 375 h->object_base = h->next_free = (char *) (obj); 376 h->chunk_limit = lp->limit; 377 h->chunk = lp; 378 } 379 else if (obj != 0) 380 /* obj is not in any of the chunks! */ 381 abort (); 382} 383 384# ifdef _LIBC 385/* Older versions of libc used a function _obstack_free intended to be 386 called by non-GCC compilers. */ 387strong_alias (obstack_free, _obstack_free) 388# endif 389\f 390int 391_obstack_memory_used (struct obstack *h) 392{ 393 register struct _obstack_chunk* lp; 394 register int nbytes = 0; 395 396 for (lp = h->chunk; lp != 0; lp = lp->prev) 397 { 398 nbytes += lp->limit - (char *) lp; 399 } 400 return nbytes; 401} 402\f 403/* Define the error handler. */ 404# ifdef _LIBC 405# include <libintl.h> 406# else 407# include "gettext.h" 408# endif 409# ifndef _ 410# define _(msgid) gettext (msgid) 411# endif 412 413# ifdef _LIBC 414# include <libio/iolibio.h> 415# endif 416 417# ifndef __attribute__ 418/* This feature is available in gcc versions 2.5 and later. */ 419# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) 420# define __attribute__(Spec) /* empty */ 421# endif 422# endif 423 424static void 425__attribute__ ((noreturn)) 426print_and_abort (void) 427{ 428 /* Don't change any of these strings. Yes, it would be possible to add 429 the newline to the string and use fputs or so. But this must not 430 happen because the "memory exhausted" message appears in other places 431 like this and the translation should be reused instead of creating 432 a very similar string which requires a separate translation. */ 433# ifdef _LIBC 434 (void) __fxprintf (NULL, "%s\n", _("memory exhausted")); 435# else 436 fprintf (stderr, "%s\n", _("memory exhausted")); 437# endif 438 exit (obstack_exit_failure); 439} 440 441#endif /* !ELIDE_CODE */