malloc/obstack.c

   1 /* obstack.c - subroutines used implicitly by object stack macros
   2    Copyright (C) 1988,89,90,91,92,93,94,96,97 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU C Library.  Its master source is NOT part of
   5    the C library, however.  The master source lives in /gd/gnu/lib.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Library General Public License as
   9    published by the Free Software Foundation; either version 2 of the
  10    License, or (at your option) any later version.
  11
  12    The GNU C Library 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 GNU
  15    Library General Public License for more details.
  16
  17    You should have received a copy of the GNU Library General Public
  18    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  19    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include "obstack.h"
  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
  51 #ifndef ELIDE_CODE
  52
  53
  54 #if defined (__STDC__) && __STDC__
  55 #define POINTER void *
  56 #else
  57 #define POINTER char *
  58 #endif
  59
  60 /* Determine default alignment.  */
  61 struct fooalign {char x; double d;};
  62 #define DEFAULT_ALIGNMENT  \
  63   ((PTR_INT_TYPE) ((char *) &((struct fooalign *) 0)->d - (char *) 0))
  64 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
  65    But in fact it might be less smart and round addresses to as much as
  66    DEFAULT_ROUNDING.  So we prepare for it to do that.  */
  67 union fooround {long x; double d;};
  68 #define DEFAULT_ROUNDING (sizeof (union fooround))
  69
  70 /* When we copy a long block of data, this is the unit to do it with.
  71    On some machines, copying successive ints does not work;
  72    in such a case, redefine COPYING_UNIT to `long' (if that works)
  73    or `char' as a last resort.  */
  74 #ifndef COPYING_UNIT
  75 #define COPYING_UNIT int
  76 #endif
  77
  78
  79 /* The functions allocating more room by calling `obstack_chunk_alloc'
  80    jump to the handler pointed to by `obstack_alloc_failed_handler'.
  81    This variable by default points to the internal function
  82    `print_and_abort'.  */
  83 #if defined (__STDC__) && __STDC__
  84 static void print_and_abort (void);
  85 void (*obstack_alloc_failed_handler) (void) = print_and_abort;
  86 #else
  87 static void print_and_abort ();
  88 void (*obstack_alloc_failed_handler) () = print_and_abort;
  89 #endif
  90
  91 /* Exit value used when `print_and_abort' is used.  */
  92 #if defined __GNU_LIBRARY__ || defined HAVE_STDLIB_H
  93 #include <stdlib.h>
  94 #endif
  95 #ifndef EXIT_FAILURE
  96 #define EXIT_FAILURE 1
  97 #endif
  98 int obstack_exit_failure = EXIT_FAILURE;
  99
 100 /* The non-GNU-C macros copy the obstack into this global variable
 101    to avoid multiple evaluation.  */
 102
 103 struct obstack *_obstack;
 104
 105 /* Define a macro that either calls functions with the traditional malloc/free
 106    calling interface, or calls functions with the mmalloc/mfree interface
 107    (that adds an extra first argument), based on the state of use_extra_arg.
 108    For free, do not use ?:, since some compilers, like the MIPS compilers,
 109    do not allow (expr) ? void : void.  */
 110
 111 #if defined (__STDC__) && __STDC__
 112 #define CALL_CHUNKFUN(h, size) \
 113   (((h) -> use_extra_arg) \
 114    ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
 115    : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
 116
 117 #define CALL_FREEFUN(h, old_chunk) \
 118   do { \
 119     if ((h) -> use_extra_arg) \
 120       (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
 121     else \
 122       (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
 123   } while (0)
 124 #else
 125 #define CALL_CHUNKFUN(h, size) \
 126   (((h) -> use_extra_arg) \
 127    ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
 128    : (*(struct _obstack_chunk *(*) ()) (h)->chunkfun) ((size)))
 129
 130 #define CALL_FREEFUN(h, old_chunk) \
 131   do { \
 132     if ((h) -> use_extra_arg) \
 133       (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
 134     else \
 135       (*(void (*) ()) (h)->freefun) ((old_chunk)); \
 136   } while (0)
 137 #endif
 138
 139 \f
 140 /* Initialize an obstack H for use.  Specify chunk size SIZE (0 means default).
 141    Objects start on multiples of ALIGNMENT (0 means use default).
 142    CHUNKFUN is the function to use to allocate chunks,
 143    and FREEFUN the function to free them.
 144
 145    Return nonzero if successful, zero if out of memory.
 146    To recover from an out of memory error,
 147    free up some memory, then call this again.  */
 148
 149 int
 150 _obstack_begin (h, size, alignment, chunkfun, freefun)
 151      struct obstack *h;
 152      int size;
 153      int alignment;
 154 #if defined (__STDC__) && __STDC__
 155      POINTER (*chunkfun) (long);
 156      void (*freefun) (void *);
 157 #else
 158      POINTER (*chunkfun) ();
 159      void (*freefun) ();
 160 #endif
 161 {
 162   register struct _obstack_chunk *chunk; /* points to new chunk */
 163
 164   if (alignment == 0)
 165     alignment = DEFAULT_ALIGNMENT;
 166   if (size == 0)
 167     /* Default size is what GNU malloc can fit in a 4096-byte block.  */
 168     {
 169       /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
 170          Use the values for range checking, because if range checking is off,
 171          the extra bytes won't be missed terribly, but if range checking is on
 172          and we used a larger request, a whole extra 4096 bytes would be
 173          allocated.
 174
 175          These number are irrelevant to the new GNU malloc.  I suspect it is
 176          less sensitive to the size of the request.  */
 177       int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
 178                     + 4 + DEFAULT_ROUNDING - 1)
 179                    & ~(DEFAULT_ROUNDING - 1));
 180       size = 4096 - extra;
 181     }
 182
 183 #if defined (__STDC__) && __STDC__
 184   h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
 185   h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
 186 #else
 187   h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
 188   h->freefun = freefun;
 189 #endif
 190   h->chunk_size = size;
 191   h->alignment_mask = alignment - 1;
 192   h->use_extra_arg = 0;
 193
 194   chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
 195   if (!chunk)
 196     (*obstack_alloc_failed_handler) ();
 197   h->next_free = h->object_base = chunk->contents;
 198   h->chunk_limit = chunk->limit
 199     = (char *) chunk + h->chunk_size;
 200   chunk->prev = 0;
 201   /* The initial chunk now contains no empty object.  */
 202   h->maybe_empty_object = 0;
 203   h->alloc_failed = 0;
 204   return 1;
 205 }
 206
 207 int
 208 _obstack_begin_1 (h, size, alignment, chunkfun, freefun, arg)
 209      struct obstack *h;
 210      int size;
 211      int alignment;
 212 #if defined (__STDC__) && __STDC__
 213      POINTER (*chunkfun) (POINTER, long);
 214      void (*freefun) (POINTER, POINTER);
 215 #else
 216      POINTER (*chunkfun) ();
 217      void (*freefun) ();
 218 #endif
 219      POINTER arg;
 220 {
 221   register struct _obstack_chunk *chunk; /* points to new chunk */
 222
 223   if (alignment == 0)
 224     alignment = DEFAULT_ALIGNMENT;
 225   if (size == 0)
 226     /* Default size is what GNU malloc can fit in a 4096-byte block.  */
 227     {
 228       /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
 229          Use the values for range checking, because if range checking is off,
 230          the extra bytes won't be missed terribly, but if range checking is on
 231          and we used a larger request, a whole extra 4096 bytes would be
 232          allocated.
 233
 234          These number are irrelevant to the new GNU malloc.  I suspect it is
 235          less sensitive to the size of the request.  */
 236       int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
 237                     + 4 + DEFAULT_ROUNDING - 1)
 238                    & ~(DEFAULT_ROUNDING - 1));
 239       size = 4096 - extra;
 240     }
 241
 242 #if defined(__STDC__) && __STDC__
 243   h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
 244   h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
 245 #else
 246   h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
 247   h->freefun = freefun;
 248 #endif
 249   h->chunk_size = size;
 250   h->alignment_mask = alignment - 1;
 251   h->extra_arg = arg;
 252   h->use_extra_arg = 1;
 253
 254   chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
 255   if (!chunk)
 256     (*obstack_alloc_failed_handler) ();
 257   h->next_free = h->object_base = chunk->contents;
 258   h->chunk_limit = chunk->limit
 259     = (char *) chunk + h->chunk_size;
 260   chunk->prev = 0;
 261   /* The initial chunk now contains no empty object.  */
 262   h->maybe_empty_object = 0;
 263   h->alloc_failed = 0;
 264   return 1;
 265 }
 266
 267 /* Allocate a new current chunk for the obstack *H
 268    on the assumption that LENGTH bytes need to be added
 269    to the current object, or a new object of length LENGTH allocated.
 270    Copies any partial object from the end of the old chunk
 271    to the beginning of the new one.  */
 272
 273 void
 274 _obstack_newchunk (h, length)
 275      struct obstack *h;
 276      int length;
 277 {
 278   register struct _obstack_chunk *old_chunk = h->chunk;
 279   register struct _obstack_chunk *new_chunk;
 280   register long new_size;
 281   register int obj_size = h->next_free - h->object_base;
 282   register int i;
 283   int already;
 284
 285   /* Compute size for new chunk.  */
 286   new_size = (obj_size + length) + (obj_size >> 3) + 100;
 287   if (new_size < h->chunk_size)
 288     new_size = h->chunk_size;
 289
 290   /* Allocate and initialize the new chunk.  */
 291   new_chunk = CALL_CHUNKFUN (h, new_size);
 292   if (!new_chunk)
 293     (*obstack_alloc_failed_handler) ();
 294   h->chunk = new_chunk;
 295   new_chunk->prev = old_chunk;
 296   new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
 297
 298   /* Move the existing object to the new chunk.
 299      Word at a time is fast and is safe if the object
 300      is sufficiently aligned.  */
 301   if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
 302     {
 303       for (i = obj_size / sizeof (COPYING_UNIT) - 1;
 304            i >= 0; i--)
 305         ((COPYING_UNIT *)new_chunk->contents)[i]
 306           = ((COPYING_UNIT *)h->object_base)[i];
 307       /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
 308          but that can cross a page boundary on a machine
 309          which does not do strict alignment for COPYING_UNITS.  */
 310       already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
 311     }
 312   else
 313     already = 0;
 314   /* Copy remaining bytes one by one.  */
 315   for (i = already; i < obj_size; i++)
 316     new_chunk->contents[i] = h->object_base[i];
 317
 318   /* If the object just copied was the only data in OLD_CHUNK,
 319      free that chunk and remove it from the chain.
 320      But not if that chunk might contain an empty object.  */
 321   if (h->object_base == old_chunk->contents && ! h->maybe_empty_object)
 322     {
 323       new_chunk->prev = old_chunk->prev;
 324       CALL_FREEFUN (h, old_chunk);
 325     }
 326
 327   h->object_base = new_chunk->contents;
 328   h->next_free = h->object_base + obj_size;
 329   /* The new chunk certainly contains no empty object yet.  */
 330   h->maybe_empty_object = 0;
 331 }
 332
 333 /* Return nonzero if object OBJ has been allocated from obstack H.
 334    This is here for debugging.
 335    If you use it in a program, you are probably losing.  */
 336
 337 #if defined (__STDC__) && __STDC__
 338 /* Suppress -Wmissing-prototypes warning.  We don't want to declare this in
 339    obstack.h because it is just for debugging.  */
 340 int _obstack_allocated_p (struct obstack *h, POINTER obj);
 341 #endif
 342
 343 int
 344 _obstack_allocated_p (h, obj)
 345      struct obstack *h;
 346      POINTER obj;
 347 {
 348   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 349   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 350
 351   lp = (h)->chunk;
 352   /* We use >= rather than > since the object cannot be exactly at
 353      the beginning of the chunk but might be an empty object exactly
 354      at the end of an adjacent chunk.  */
 355   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 356     {
 357       plp = lp->prev;
 358       lp = plp;
 359     }
 360   return lp != 0;
 361 }
 362 \f
 363 /* Free objects in obstack H, including OBJ and everything allocate
 364    more recently than OBJ.  If OBJ is zero, free everything in H.  */
 365
 366 #undef obstack_free
 367
 368 /* This function has two names with identical definitions.
 369    This is the first one, called from non-ANSI code.  */
 370
 371 void
 372 _obstack_free (h, obj)
 373      struct obstack *h;
 374      POINTER obj;
 375 {
 376   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 377   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 378
 379   lp = h->chunk;
 380   /* We use >= because there cannot be an object at the beginning of a chunk.
 381      But there can be an empty object at that address
 382      at the end of another chunk.  */
 383   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 384     {
 385       plp = lp->prev;
 386       CALL_FREEFUN (h, lp);
 387       lp = plp;
 388       /* If we switch chunks, we can't tell whether the new current
 389          chunk contains an empty object, so assume that it may.  */
 390       h->maybe_empty_object = 1;
 391     }
 392   if (lp)
 393     {
 394       h->object_base = h->next_free = (char *) (obj);
 395       h->chunk_limit = lp->limit;
 396       h->chunk = lp;
 397     }
 398   else if (obj != 0)
 399     /* obj is not in any of the chunks! */
 400     abort ();
 401 }
 402
 403 /* This function is used from ANSI code.  */
 404
 405 void
 406 obstack_free (h, obj)
 407      struct obstack *h;
 408      POINTER obj;
 409 {
 410   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 411   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 412
 413   lp = h->chunk;
 414   /* We use >= because there cannot be an object at the beginning of a chunk.
 415      But there can be an empty object at that address
 416      at the end of another chunk.  */
 417   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 418     {
 419       plp = lp->prev;
 420       CALL_FREEFUN (h, lp);
 421       lp = plp;
 422       /* If we switch chunks, we can't tell whether the new current
 423          chunk contains an empty object, so assume that it may.  */
 424       h->maybe_empty_object = 1;
 425     }
 426   if (lp)
 427     {
 428       h->object_base = h->next_free = (char *) (obj);
 429       h->chunk_limit = lp->limit;
 430       h->chunk = lp;
 431     }
 432   else if (obj != 0)
 433     /* obj is not in any of the chunks! */
 434     abort ();
 435 }
 436 \f
 437 int
 438 _obstack_memory_used (h)
 439      struct obstack *h;
 440 {
 441   register struct _obstack_chunk* lp;
 442   register int nbytes = 0;
 443
 444   for (lp = h->chunk; lp != 0; lp = lp->prev)
 445     {
 446       nbytes += lp->limit - (char *) lp;
 447     }
 448   return nbytes;
 449 }
 450 \f
 451 /* Define the error handler.  */
 452 #ifndef _
 453 # ifdef HAVE_LIBINTL_H
 454 #  include <libintl.h>
 455 #  ifndef _
 456 #   define _(Str) gettext (Str)
 457 #  endif
 458 # else
 459 #  define _(Str) (Str)
 460 # endif
 461 #endif
 462
 463 static void
 464 print_and_abort ()
 465 {
 466   fputs (_("memory exhausted\n"), stderr);
 467   exit (obstack_exit_failure);
 468 }
 469 \f
 470 #if 0
 471 /* These are now turned off because the applications do not use it
 472    and it uses bcopy via obstack_grow, which causes trouble on sysV.  */
 473
 474 /* Now define the functional versions of the obstack macros.
 475    Define them to simply use the corresponding macros to do the job.  */
 476
 477 #if defined (__STDC__) && __STDC__
 478 /* These function definitions do not work with non-ANSI preprocessors;
 479    they won't pass through the macro names in parentheses.  */
 480
 481 /* The function names appear in parentheses in order to prevent
 482    the macro-definitions of the names from being expanded there.  */
 483
 484 POINTER (obstack_base) (obstack)
 485      struct obstack *obstack;
 486 {
 487   return obstack_base (obstack);
 488 }
 489
 490 POINTER (obstack_next_free) (obstack)
 491      struct obstack *obstack;
 492 {
 493   return obstack_next_free (obstack);
 494 }
 495
 496 int (obstack_object_size) (obstack)
 497      struct obstack *obstack;
 498 {
 499   return obstack_object_size (obstack);
 500 }
 501
 502 int (obstack_room) (obstack)
 503      struct obstack *obstack;
 504 {
 505   return obstack_room (obstack);
 506 }
 507
 508 int (obstack_make_room) (obstack, length)
 509      struct obstack *obstack;
 510      int length;
 511 {
 512   return obstack_make_room (obstack, length);
 513 }
 514
 515 void (obstack_grow) (obstack, pointer, length)
 516      struct obstack *obstack;
 517      POINTER pointer;
 518      int length;
 519 {
 520   obstack_grow (obstack, pointer, length);
 521 }
 522
 523 void (obstack_grow0) (obstack, pointer, length)
 524      struct obstack *obstack;
 525      POINTER pointer;
 526      int length;
 527 {
 528   obstack_grow0 (obstack, pointer, length);
 529 }
 530
 531 void (obstack_1grow) (obstack, character)
 532      struct obstack *obstack;
 533      int character;
 534 {
 535   obstack_1grow (obstack, character);
 536 }
 537
 538 void (obstack_blank) (obstack, length)
 539      struct obstack *obstack;
 540      int length;
 541 {
 542   obstack_blank (obstack, length);
 543 }
 544
 545 void (obstack_1grow_fast) (obstack, character)
 546      struct obstack *obstack;
 547      int character;
 548 {
 549   obstack_1grow_fast (obstack, character);
 550 }
 551
 552 void (obstack_blank_fast) (obstack, length)
 553      struct obstack *obstack;
 554      int length;
 555 {
 556   obstack_blank_fast (obstack, length);
 557 }
 558
 559 POINTER (obstack_finish) (obstack)
 560      struct obstack *obstack;
 561 {
 562   return obstack_finish (obstack);
 563 }
 564
 565 POINTER (obstack_alloc) (obstack, length)
 566      struct obstack *obstack;
 567      int length;
 568 {
 569   return obstack_alloc (obstack, length);
 570 }
 571
 572 POINTER (obstack_copy) (obstack, pointer, length)
 573      struct obstack *obstack;
 574      POINTER pointer;
 575      int length;
 576 {
 577   return obstack_copy (obstack, pointer, length);
 578 }
 579
 580 POINTER (obstack_copy0) (obstack, pointer, length)
 581      struct obstack *obstack;
 582      POINTER pointer;
 583      int length;
 584 {
 585   return obstack_copy0 (obstack, pointer, length);
 586 }
 587
 588 #endif /* __STDC__ */
 589
 590 #endif /* 0 */
 591
 592 #endif  /* !ELIDE_CODE */