75440d9c792f40f2d27208ffbe8217ccd842504b
   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 */