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. */ 57union fooround 58{ 59 uintmax_t i; 60 long double d; 61 void *p; 62}; 63struct 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. */ 71enum 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'. */ 92static void print_and_abort (void); 93void (*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 98int 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. */ 109struct obstack *_obstack_compat; 110compat_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). 135 Objects start on multiples of ALIGNMENT (0 means use default). 136 CHUNKFUN is the function to use to allocate chunks, 137 and FREEFUN the function to free them. 138 139 Return nonzero if successful, calls obstack_alloc_failed_handler if 140 allocation fails. */ 141 142int 143_obstack_begin (struct obstack *h, 144 int size, int alignment, 145 void *(*chunkfun) (long), 146 void (*freefun) (void *)) 147{ 148 register struct _obstack_chunk *chunk; /* points to new chunk */ 149 150 if (alignment == 0) 151 alignment = DEFAULT_ALIGNMENT; 152 if (size == 0) 153 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 154 { 155 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 156 Use the values for range checking, because if range checking is off, 157 the extra bytes won't be missed terribly, but if range checking is on 158 and we used a larger request, a whole extra 4096 bytes would be 159 allocated. 160 161 These number are irrelevant to the new GNU malloc. I suspect it is 162 less sensitive to the size of the request. */ 163 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 164 + 4 + DEFAULT_ROUNDING - 1) 165 & ~(DEFAULT_ROUNDING - 1)); 166 size = 4096 - extra; 167 } 168 169 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun; 170 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 171 h->chunk_size = size; 172 h->alignment_mask = alignment - 1; 173 h->use_extra_arg = 0; 174 175 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 176 if (!chunk) 177 (*obstack_alloc_failed_handler) (); 178 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 179 alignment - 1); 180 h->chunk_limit = chunk->limit 181 = (char *) chunk + h->chunk_size; 182 chunk->prev = 0; 183 /* The initial chunk now contains no empty object. */ 184 h->maybe_empty_object = 0; 185 h->alloc_failed = 0; 186 return 1; 187} 188 189int 190_obstack_begin_1 (struct obstack *h, int size, int alignment, 191 void *(*chunkfun) (void *, long), 192 void (*freefun) (void *, void *), 193 void *arg) 194{ 195 register struct _obstack_chunk *chunk; /* points to new chunk */ 196 197 if (alignment == 0) 198 alignment = DEFAULT_ALIGNMENT; 199 if (size == 0) 200 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 201 { 202 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 203 Use the values for range checking, because if range checking is off, 204 the extra bytes won't be missed terribly, but if range checking is on 205 and we used a larger request, a whole extra 4096 bytes would be 206 allocated. 207 208 These number are irrelevant to the new GNU malloc. I suspect it is 209 less sensitive to the size of the request. */ 210 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 211 + 4 + DEFAULT_ROUNDING - 1) 212 & ~(DEFAULT_ROUNDING - 1)); 213 size = 4096 - extra; 214 } 215 216 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun; 217 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 218 h->chunk_size = size; 219 h->alignment_mask = alignment - 1; 220 h->extra_arg = arg; 221 h->use_extra_arg = 1; 222 223 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 224 if (!chunk) 225 (*obstack_alloc_failed_handler) (); 226 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 227 alignment - 1); 228 h->chunk_limit = chunk->limit 229 = (char *) chunk + h->chunk_size; 230 chunk->prev = 0; 231 /* The initial chunk now contains no empty object. */ 232 h->maybe_empty_object = 0; 233 h->alloc_failed = 0; 234 return 1; 235} 236 237/* Allocate a new current chunk for the obstack *H 238 on the assumption that LENGTH bytes need to be added 239 to the current object, or a new object of length LENGTH allocated. 240 Copies any partial object from the end of the old chunk 241 to the beginning of the new one. */ 242 243void 244_obstack_newchunk (struct obstack *h, int length) 245{ 246 register struct _obstack_chunk *old_chunk = h->chunk; 247 register struct _obstack_chunk *new_chunk; 248 register long new_size; 249 register long obj_size = h->next_free - h->object_base; 250 register long i; 251 long already; 252 char *object_base; 253 254 /* Compute size for new chunk. */ 255 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100; 256 if (new_size < h->chunk_size) 257 new_size = h->chunk_size; 258 259 /* Allocate and initialize the new chunk. */ 260 new_chunk = CALL_CHUNKFUN (h, new_size); 261 if (!new_chunk) 262 (*obstack_alloc_failed_handler) (); 263 h->chunk = new_chunk; 264 new_chunk->prev = old_chunk; 265 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; 266 267 /* Compute an aligned object_base in the new chunk */ 268 object_base = 269 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask); 270 271 /* Move the existing object to the new chunk. 272 Word at a time is fast and is safe if the object 273 is sufficiently aligned. */ 274 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT) 275 { 276 for (i = obj_size / sizeof (COPYING_UNIT) - 1; 277 i >= 0; i--) 278 ((COPYING_UNIT *)object_base)[i] 279 = ((COPYING_UNIT *)h->object_base)[i]; 280 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT, 281 but that can cross a page boundary on a machine 282 which does not do strict alignment for COPYING_UNITS. */ 283 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT); 284 } 285 else 286 already = 0; 287 /* Copy remaining bytes one by one. */ 288 for (i = already; i < obj_size; i++) 289 object_base[i] = h->object_base[i]; 290 291 /* If the object just copied was the only data in OLD_CHUNK, 292 free that chunk and remove it from the chain. 293 But not if that chunk might contain an empty object. */ 294 if (! h->maybe_empty_object 295 && (h->object_base 296 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents, 297 h->alignment_mask))) 298 { 299 new_chunk->prev = old_chunk->prev; 300 CALL_FREEFUN (h, old_chunk); 301 } 302 303 h->object_base = object_base; 304 h->next_free = h->object_base + obj_size; 305 /* The new chunk certainly contains no empty object yet. */ 306 h->maybe_empty_object = 0; 307} 308# ifdef _LIBC 309libc_hidden_def (_obstack_newchunk) 310# endif 311 312/* Return nonzero if object OBJ has been allocated from obstack H. 313 This is here for debugging. 314 If you use it in a program, you are probably losing. */ 315 316/* Suppress -Wmissing-prototypes warning. We don't want to declare this in 317 obstack.h because it is just for debugging. */ 318int _obstack_allocated_p (struct obstack *h, void *obj); 319 320int 321_obstack_allocated_p (struct obstack *h, void *obj) 322{ 323 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 324 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 325 326 lp = (h)->chunk; 327 /* We use >= rather than > since the object cannot be exactly at 328 the beginning of the chunk but might be an empty object exactly 329 at the end of an adjacent chunk. */ 330 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 331 { 332 plp = lp->prev; 333 lp = plp; 334 } 335 return lp != 0; 336} 337 338/* Free objects in obstack H, including OBJ and everything allocate 339 more recently than OBJ. If OBJ is zero, free everything in H. */ 340 341# undef obstack_free 342 343void 344__obstack_free (struct obstack *h, void *obj) 345{ 346 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 347 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 348 349 lp = h->chunk; 350 /* We use >= because there cannot be an object at the beginning of a chunk. 351 But there can be an empty object at that address 352 at the end of another chunk. */ 353 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 354 { 355 plp = lp->prev; 356 CALL_FREEFUN (h, lp); 357 lp = plp; 358 /* If we switch chunks, we can't tell whether the new current 359 chunk contains an empty object, so assume that it may. */ 360 h->maybe_empty_object = 1; 361 } 362 if (lp) 363 { 364 h->object_base = h->next_free = (char *) (obj); 365 h->chunk_limit = lp->limit; 366 h->chunk = lp; 367 } 368 else if (obj != 0) 369 /* obj is not in any of the chunks! */ 370 abort (); 371} 372 373# ifdef _LIBC 374/* Older versions of libc used a function _obstack_free intended to be 375 called by non-GCC compilers. */ 376strong_alias (obstack_free, _obstack_free) 377# endif 378 379int 380_obstack_memory_used (struct obstack *h) 381{ 382 register struct _obstack_chunk* lp; 383 register int nbytes = 0; 384 385 for (lp = h->chunk; lp != 0; lp = lp->prev) 386 { 387 nbytes += lp->limit - (char *) lp; 388 } 389 return nbytes; 390} 391 392/* Define the error handler. */ 393# ifdef _LIBC 394# include <libintl.h> 395# else 396# include "gettext.h" 397# endif 398# ifndef _ 399# define _(msgid) gettext (msgid) 400# endif 401 402# ifdef _LIBC 403# include <libio/iolibio.h> 404# endif 405 406# ifndef __attribute__ 407/* This feature is available in gcc versions 2.5 and later. */ 408# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5) 409# define __attribute__(Spec) /* empty */ 410# endif 411# endif 412 413static void 414__attribute__ ((noreturn)) 415print_and_abort (void) 416{ 417 /* Don't change any of these strings. Yes, it would be possible to add 418 the newline to the string and use fputs or so. But this must not 419 happen because the "memory exhausted" message appears in other places 420 like this and the translation should be reused instead of creating 421 a very similar string which requires a separate translation. */ 422# ifdef _LIBC 423 (void) __fxprintf (NULL, "%s\n", _("memory exhausted")); 424# else 425 fprintf (stderr, "%s\n", _("memory exhausted")); 426# endif 427 exit (obstack_exit_failure); 428} 429 430#endif /* !ELIDE_CODE */ 431