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