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 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 _LIBC 22# include <obstack.h> 23# include <shlib-compat.h> 24#else 25# include <config.h> 26# include "obstack.h" 27#endif 28 29/* NOTE BEFORE MODIFYING THIS FILE: This version number must be 30 incremented whenever callers compiled using an old obstack.h can no 31 longer properly call the functions in this obstack.c. */ 32#define OBSTACK_INTERFACE_VERSION 1 33 34/* Comment out all this code if we are using the GNU C Library, and are not 35 actually compiling the library itself, and the installed library 36 supports the same library interface we do. This code is part of the GNU 37 C Library, but also included in many other GNU distributions. Compiling 38 and linking in this code is a waste when using the GNU C library 39 (especially if it is a shared library). Rather than having every GNU 40 program understand `configure --with-gnu-libc' and omit the object 41 files, it is simpler to just do this in the source for each such file. */ 42 43#include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */ 44#if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1 45# include <gnu-versions.h> 46# if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION 47# define ELIDE_CODE 48# endif 49#endif 50 51#include <stddef.h> 52 53#ifndef ELIDE_CODE 54 55# include <stdint.h> 56 57/* Determine default alignment. */ 58union fooround 59{ 60 uintmax_t i; 61 long double d; 62 void *p; 63}; 64struct fooalign 65{ 66 char c; 67 union fooround u; 68}; 69/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. 70 But in fact it might be less smart and round addresses to as much as 71 DEFAULT_ROUNDING. So we prepare for it to do that. */ 72enum 73 { 74 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u), 75 DEFAULT_ROUNDING = sizeof (union fooround) 76 }; 77 78/* When we copy a long block of data, this is the unit to do it with. 79 On some machines, copying successive ints does not work; 80 in such a case, redefine COPYING_UNIT to `long' (if that works) 81 or `char' as a last resort. */ 82# ifndef COPYING_UNIT 83# define COPYING_UNIT int 84# endif 85 86 87/* The functions allocating more room by calling `obstack_chunk_alloc' 88 jump to the handler pointed to by `obstack_alloc_failed_handler'. 89 This can be set to a user defined function which should either 90 abort gracefully or use longjump - but shouldn't return. This 91 variable by default points to the internal function 92 `print_and_abort'. */ 93static void print_and_abort (void); 94void (*obstack_alloc_failed_handler) (void) = print_and_abort; 95 96/* Exit value used when `print_and_abort' is used. */ 97# include <stdlib.h> 98# ifdef _LIBC 99int obstack_exit_failure = EXIT_FAILURE; 100# else 101# include "exitfail.h" 102# define obstack_exit_failure exit_failure 103# endif 104 105# ifdef _LIBC 106# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4) 107/* A looong time ago (before 1994, anyway; we're not sure) this global variable 108 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C 109 library still exports it because somebody might use it. */ 110struct obstack *_obstack_compat; 111compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0); 112# endif 113# endif 114 115/* Define a macro that either calls functions with the traditional malloc/free 116 calling interface, or calls functions with the mmalloc/mfree interface 117 (that adds an extra first argument), based on the state of use_extra_arg. 118 For free, do not use ?:, since some compilers, like the MIPS compilers, 119 do not allow (expr) ? void : void. */ 120 121# define CALL_CHUNKFUN(h, size) \ 122 (((h) -> use_extra_arg) \ 123 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \ 124 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size))) 125 126# define CALL_FREEFUN(h, old_chunk) \ 127 do { \ 128 if ((h) -> use_extra_arg) \ 129 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \ 130 else \ 131 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \ 132 } while (0) 133 134 135/* 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 143int 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 190int 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 244void 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 310libc_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. */ 319int _obstack_allocated_p (struct obstack *h, void *obj); 320 321int 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 340 more recently than OBJ. If OBJ is zero, free everything in H. */ 341 342# undef obstack_free 343 344void 345__obstack_free (struct obstack *h, void *obj) 346{ 347 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 348 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 349 350 lp = h->chunk; 351 /* We use >= because there cannot be an object at the beginning of a chunk. 352 But there can be an empty object at that address 353 at the end of another chunk. */ 354 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 355 { 356 plp = lp->prev; 357 CALL_FREEFUN (h, lp); 358 lp = plp; 359 /* If we switch chunks, we can't tell whether the new current 360 chunk contains an empty object, so assume that it may. */ 361 h->maybe_empty_object = 1; 362 } 363 if (lp) 364 { 365 h->object_base = h->next_free = (char *) (obj); 366 h->chunk_limit = lp->limit; 367 h->chunk = lp; 368 } 369 else if (obj != 0) 370 /* obj is not in any of the chunks! */ 371 abort (); 372} 373 374# ifdef _LIBC 375/* Older versions of libc used a function _obstack_free intended to be 376 called by non-GCC compilers. */ 377strong_alias (obstack_free, _obstack_free) 378# endif 379 380int 381_obstack_memory_used (struct obstack *h) 382{ 383 register struct _obstack_chunk* lp; 384 register int nbytes = 0; 385 386 for (lp = h->chunk; lp != 0; lp = lp->prev) 387 { 388 nbytes += lp->limit - (char *) lp; 389 } 390 return nbytes; 391} 392 393/* Define the error handler. */ 394# ifdef _LIBC 395# include <libintl.h> 396# else 397# include "gettext.h" 398# endif 399# ifndef _ 400# define _(msgid) gettext (msgid) 401# endif 402 403# ifdef _LIBC 404# include <libio/iolibio.h> 405# endif 406 407# ifndef __attribute__ 408/* This feature is available in gcc versions 2.5 and later. */ 409# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) 410# define __attribute__(Spec) /* empty */ 411# endif 412# endif 413 414static void 415__attribute__ ((noreturn)) 416print_and_abort (void) 417{ 418 /* Don't change any of these strings. Yes, it would be possible to add 419 the newline to the string and use fputs or so. But this must not 420 happen because the "memory exhausted" message appears in other places 421 like this and the translation should be reused instead of creating 422 a very similar string which requires a separate translation. */ 423# ifdef _LIBC 424 (void) __fxprintf (NULL, "%s\n", _("memory exhausted")); 425# else 426 fprintf (stderr, "%s\n", _("memory exhausted")); 427# endif 428 exit (obstack_exit_failure); 429} 430 431#endif /* !ELIDE_CODE */ 432