1/* obstack.c - subroutines used implicitly by object stack macros 2 3 Copyright (C) 1988-1994, 1996-2006, 2009-2012 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18#ifdef _LIBC 19# include <obstack.h> 20# include <shlib-compat.h> 21#else 22# include <config.h> 23# include "obstack.h" 24#endif 25 26/* NOTE BEFORE MODIFYING THIS FILE: This version number must be 27 incremented whenever callers compiled using an old obstack.h can no 28 longer properly call the functions in this obstack.c. */ 29#define OBSTACK_INTERFACE_VERSION 1 30 31/* Comment out all this code if we are using the GNU C Library, and are not 32 actually compiling the library itself, and the installed library 33 supports the same library interface we do. This code is part of the GNU 34 C Library, but also included in many other GNU distributions. Compiling 35 and linking in this code is a waste when using the GNU C library 36 (especially if it is a shared library). Rather than having every GNU 37 program understand 'configure --with-gnu-libc' and omit the object 38 files, it is simpler to just do this in the source for each such file. */ 39 40#include <stdio.h> /* Random thing to get __GNU_LIBRARY__. */ 41#if !defined _LIBC && defined __GNU_LIBRARY__ && __GNU_LIBRARY__ > 1 42# include <gnu-versions.h> 43# if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION 44# define ELIDE_CODE 45# endif 46#endif 47 48#include <stddef.h> 49 50#ifndef ELIDE_CODE 51 52# include <stdint.h> 53 54/* Determine default alignment. */ 55union fooround 56{ 57 uintmax_t i; 58 long double d; 59 void *p; 60}; 61struct fooalign 62{ 63 char c; 64 union fooround u; 65}; 66/* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT. 67 But in fact it might be less smart and round addresses to as much as 68 DEFAULT_ROUNDING. So we prepare for it to do that. */ 69enum 70 { 71 DEFAULT_ALIGNMENT = offsetof (struct fooalign, u), 72 DEFAULT_ROUNDING = sizeof (union fooround) 73 }; 74 75/* When we copy a long block of data, this is the unit to do it with. 76 On some machines, copying successive ints does not work; 77 in such a case, redefine COPYING_UNIT to 'long' (if that works) 78 or 'char' as a last resort. */ 79# ifndef COPYING_UNIT 80# define COPYING_UNIT int 81# endif 82 83 84/* The functions allocating more room by calling 'obstack_chunk_alloc' 85 jump to the handler pointed to by 'obstack_alloc_failed_handler'. 86 This can be set to a user defined function which should either 87 abort gracefully or use longjump - but shouldn't return. This 88 variable by default points to the internal function 89 'print_and_abort'. */ 90static _Noreturn void print_and_abort (void); 91void (*obstack_alloc_failed_handler) (void) = print_and_abort; 92 93/* Exit value used when 'print_and_abort' is used. */ 94# include <stdlib.h> 95# ifdef _LIBC 96int obstack_exit_failure = EXIT_FAILURE; 97# else 98# include "exitfail.h" 99# define obstack_exit_failure exit_failure 100# endif 101 102# ifdef _LIBC 103# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4) 104/* A looong time ago (before 1994, anyway; we're not sure) this global variable 105 was used by non-GNU-C macros to avoid multiple evaluation. The GNU C 106 library still exports it because somebody might use it. */ 107struct obstack *_obstack_compat; 108compat_symbol (libc, _obstack_compat, _obstack, GLIBC_2_0); 109# endif 110# endif 111 112/* Define a macro that either calls functions with the traditional malloc/free 113 calling interface, or calls functions with the mmalloc/mfree interface 114 (that adds an extra first argument), based on the state of use_extra_arg. 115 For free, do not use ?:, since some compilers, like the MIPS compilers, 116 do not allow (expr) ? void : void. */ 117 118# define CALL_CHUNKFUN(h, size) \ 119 (((h) -> use_extra_arg) \ 120 ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \ 121 : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size))) 122 123# define CALL_FREEFUN(h, old_chunk) \ 124 do { \ 125 if ((h) -> use_extra_arg) \ 126 (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \ 127 else \ 128 (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \ 129 } while (0) 130 131 132/* Initialize an obstack H for use. Specify chunk size SIZE (0 means default). 133 Objects start on multiples of ALIGNMENT (0 means use default). 134 CHUNKFUN is the function to use to allocate chunks, 135 and FREEFUN the function to free them. 136 137 Return nonzero if successful, calls obstack_alloc_failed_handler if 138 allocation fails. */ 139 140int 141_obstack_begin (struct obstack *h, 142 int size, int alignment, 143 void *(*chunkfun) (long), 144 void (*freefun) (void *)) 145{ 146 register struct _obstack_chunk *chunk; /* points to new chunk */ 147 148 if (alignment == 0) 149 alignment = DEFAULT_ALIGNMENT; 150 if (size == 0) 151 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 152 { 153 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 154 Use the values for range checking, because if range checking is off, 155 the extra bytes won't be missed terribly, but if range checking is on 156 and we used a larger request, a whole extra 4096 bytes would be 157 allocated. 158 159 These number are irrelevant to the new GNU malloc. I suspect it is 160 less sensitive to the size of the request. */ 161 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 162 + 4 + DEFAULT_ROUNDING - 1) 163 & ~(DEFAULT_ROUNDING - 1)); 164 size = 4096 - extra; 165 } 166 167 h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun; 168 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 169 h->chunk_size = size; 170 h->alignment_mask = alignment - 1; 171 h->use_extra_arg = 0; 172 173 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 174 if (!chunk) 175 (*obstack_alloc_failed_handler) (); 176 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 177 alignment - 1); 178 h->chunk_limit = chunk->limit 179 = (char *) chunk + h->chunk_size; 180 chunk->prev = 0; 181 /* The initial chunk now contains no empty object. */ 182 h->maybe_empty_object = 0; 183 h->alloc_failed = 0; 184 return 1; 185} 186 187int 188_obstack_begin_1 (struct obstack *h, int size, int alignment, 189 void *(*chunkfun) (void *, long), 190 void (*freefun) (void *, void *), 191 void *arg) 192{ 193 register struct _obstack_chunk *chunk; /* points to new chunk */ 194 195 if (alignment == 0) 196 alignment = DEFAULT_ALIGNMENT; 197 if (size == 0) 198 /* Default size is what GNU malloc can fit in a 4096-byte block. */ 199 { 200 /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc. 201 Use the values for range checking, because if range checking is off, 202 the extra bytes won't be missed terribly, but if range checking is on 203 and we used a larger request, a whole extra 4096 bytes would be 204 allocated. 205 206 These number are irrelevant to the new GNU malloc. I suspect it is 207 less sensitive to the size of the request. */ 208 int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1)) 209 + 4 + DEFAULT_ROUNDING - 1) 210 & ~(DEFAULT_ROUNDING - 1)); 211 size = 4096 - extra; 212 } 213 214 h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun; 215 h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun; 216 h->chunk_size = size; 217 h->alignment_mask = alignment - 1; 218 h->extra_arg = arg; 219 h->use_extra_arg = 1; 220 221 chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size); 222 if (!chunk) 223 (*obstack_alloc_failed_handler) (); 224 h->next_free = h->object_base = __PTR_ALIGN ((char *) chunk, chunk->contents, 225 alignment - 1); 226 h->chunk_limit = chunk->limit 227 = (char *) chunk + h->chunk_size; 228 chunk->prev = 0; 229 /* The initial chunk now contains no empty object. */ 230 h->maybe_empty_object = 0; 231 h->alloc_failed = 0; 232 return 1; 233} 234 235/* Allocate a new current chunk for the obstack *H 236 on the assumption that LENGTH bytes need to be added 237 to the current object, or a new object of length LENGTH allocated. 238 Copies any partial object from the end of the old chunk 239 to the beginning of the new one. */ 240 241void 242_obstack_newchunk (struct obstack *h, int length) 243{ 244 register struct _obstack_chunk *old_chunk = h->chunk; 245 register struct _obstack_chunk *new_chunk; 246 register long new_size; 247 register long obj_size = h->next_free - h->object_base; 248 register long i; 249 long already; 250 char *object_base; 251 252 /* Compute size for new chunk. */ 253 new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100; 254 if (new_size < h->chunk_size) 255 new_size = h->chunk_size; 256 257 /* Allocate and initialize the new chunk. */ 258 new_chunk = CALL_CHUNKFUN (h, new_size); 259 if (!new_chunk) 260 (*obstack_alloc_failed_handler) (); 261 h->chunk = new_chunk; 262 new_chunk->prev = old_chunk; 263 new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size; 264 265 /* Compute an aligned object_base in the new chunk */ 266 object_base = 267 __PTR_ALIGN ((char *) new_chunk, new_chunk->contents, h->alignment_mask); 268 269 /* Move the existing object to the new chunk. 270 Word at a time is fast and is safe if the object 271 is sufficiently aligned. */ 272 if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT) 273 { 274 for (i = obj_size / sizeof (COPYING_UNIT) - 1; 275 i >= 0; i--) 276 ((COPYING_UNIT *)object_base)[i] 277 = ((COPYING_UNIT *)h->object_base)[i]; 278 /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT, 279 but that can cross a page boundary on a machine 280 which does not do strict alignment for COPYING_UNITS. */ 281 already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT); 282 } 283 else 284 already = 0; 285 /* Copy remaining bytes one by one. */ 286 for (i = already; i < obj_size; i++) 287 object_base[i] = h->object_base[i]; 288 289 /* If the object just copied was the only data in OLD_CHUNK, 290 free that chunk and remove it from the chain. 291 But not if that chunk might contain an empty object. */ 292 if (! h->maybe_empty_object 293 && (h->object_base 294 == __PTR_ALIGN ((char *) old_chunk, old_chunk->contents, 295 h->alignment_mask))) 296 { 297 new_chunk->prev = old_chunk->prev; 298 CALL_FREEFUN (h, old_chunk); 299 } 300 301 h->object_base = object_base; 302 h->next_free = h->object_base + obj_size; 303 /* The new chunk certainly contains no empty object yet. */ 304 h->maybe_empty_object = 0; 305} 306# ifdef _LIBC 307libc_hidden_def (_obstack_newchunk) 308# endif 309 310/* Return nonzero if object OBJ has been allocated from obstack H. 311 This is here for debugging. 312 If you use it in a program, you are probably losing. */ 313 314/* Suppress -Wmissing-prototypes warning. We don't want to declare this in 315 obstack.h because it is just for debugging. */ 316int _obstack_allocated_p (struct obstack *h, void *obj); 317 318int 319_obstack_allocated_p (struct obstack *h, void *obj) 320{ 321 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 322 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 323 324 lp = (h)->chunk; 325 /* We use >= rather than > since the object cannot be exactly at 326 the beginning of the chunk but might be an empty object exactly 327 at the end of an adjacent chunk. */ 328 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 329 { 330 plp = lp->prev; 331 lp = plp; 332 } 333 return lp != 0; 334} 335 336/* Free objects in obstack H, including OBJ and everything allocate 337 more recently than OBJ. If OBJ is zero, free everything in H. */ 338 339# undef obstack_free 340 341void 342__obstack_free (struct obstack *h, void *obj) 343{ 344 register struct _obstack_chunk *lp; /* below addr of any objects in this chunk */ 345 register struct _obstack_chunk *plp; /* point to previous chunk if any */ 346 347 lp = h->chunk; 348 /* We use >= because there cannot be an object at the beginning of a chunk. 349 But there can be an empty object at that address 350 at the end of another chunk. */ 351 while (lp != 0 && ((void *) lp >= obj || (void *) (lp)->limit < obj)) 352 { 353 plp = lp->prev; 354 CALL_FREEFUN (h, lp); 355 lp = plp; 356 /* If we switch chunks, we can't tell whether the new current 357 chunk contains an empty object, so assume that it may. */ 358 h->maybe_empty_object = 1; 359 } 360 if (lp) 361 { 362 h->object_base = h->next_free = (char *) (obj); 363 h->chunk_limit = lp->limit; 364 h->chunk = lp; 365 } 366 else if (obj != 0) 367 /* obj is not in any of the chunks! */ 368 abort (); 369} 370 371# ifdef _LIBC 372/* Older versions of libc used a function _obstack_free intended to be 373 called by non-GCC compilers. */ 374strong_alias (obstack_free, _obstack_free) 375# endif 376 377int 378_obstack_memory_used (struct obstack *h) 379{ 380 register struct _obstack_chunk* lp; 381 register int nbytes = 0; 382 383 for (lp = h->chunk; lp != 0; lp = lp->prev) 384 { 385 nbytes += lp->limit - (char *) lp; 386 } 387 return nbytes; 388} 389 390/* Define the error handler. */ 391# ifdef _LIBC 392# include <libintl.h> 393# else 394# include "gettext.h" 395# endif 396# ifndef _ 397# define _(msgid) gettext (msgid) 398# endif 399 400# ifdef _LIBC 401# include <libio/iolibio.h> 402# endif 403 404static _Noreturn void 405print_and_abort (void) 406{ 407 /* Don't change any of these strings. Yes, it would be possible to add 408 the newline to the string and use fputs or so. But this must not 409 happen because the "memory exhausted" message appears in other places 410 like this and the translation should be reused instead of creating 411 a very similar string which requires a separate translation. */ 412# ifdef _LIBC 413 (void) __fxprintf (NULL, "%s\n", _("memory exhausted")); 414# else 415 fprintf (stderr, "%s\n", _("memory exhausted")); 416# endif 417 exit (obstack_exit_failure); 418} 419 420#endif /* !ELIDE_CODE */ 421