malloc/obstack.c

   1 /* obstack.c - subroutines used implicitly by object stack macros
   2    Copyright (C) 1988,89,90,91,92,93,94,96,97,98 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 can be set to a user defined function which should either
  82    abort gracefully or use longjump - but shouldn't return.  This
  83    variable by default points to the internal function
  84    `print_and_abort'.  */
  85 #if defined (__STDC__) && __STDC__
  86 static void print_and_abort (void);
  87 void (*obstack_alloc_failed_handler) (void) = print_and_abort;
  88 #else
  89 static void print_and_abort ();
  90 void (*obstack_alloc_failed_handler) () = print_and_abort;
  91 #endif
  92
  93 /* Exit value used when `print_and_abort' is used.  */
  94 #if defined __GNU_LIBRARY__ || defined HAVE_STDLIB_H
  95 #include <stdlib.h>
  96 #endif
  97 #ifndef EXIT_FAILURE
  98 #define EXIT_FAILURE 1
  99 #endif
 100 int obstack_exit_failure = EXIT_FAILURE;
 101
 102 /* The non-GNU-C macros copy the obstack into this global variable
 103    to avoid multiple evaluation.  */
 104
 105 struct obstack *_obstack;
 106
 107 /* Define a macro that either calls functions with the traditional malloc/free
 108    calling interface, or calls functions with the mmalloc/mfree interface
 109    (that adds an extra first argument), based on the state of use_extra_arg.
 110    For free, do not use ?:, since some compilers, like the MIPS compilers,
 111    do not allow (expr) ? void : void.  */
 112
 113 #if defined (__STDC__) && __STDC__
 114 #define CALL_CHUNKFUN(h, size) \
 115   (((h) -> use_extra_arg) \
 116    ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
 117    : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
 118
 119 #define CALL_FREEFUN(h, old_chunk) \
 120   do { \
 121     if ((h) -> use_extra_arg) \
 122       (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
 123     else \
 124       (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
 125   } while (0)
 126 #else
 127 #define CALL_CHUNKFUN(h, size) \
 128   (((h) -> use_extra_arg) \
 129    ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
 130    : (*(struct _obstack_chunk *(*) ()) (h)->chunkfun) ((size)))
 131
 132 #define CALL_FREEFUN(h, old_chunk) \
 133   do { \
 134     if ((h) -> use_extra_arg) \
 135       (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
 136     else \
 137       (*(void (*) ()) (h)->freefun) ((old_chunk)); \
 138   } while (0)
 139 #endif
 140
 141 \f
 142 /* Initialize an obstack H for use.  Specify chunk size SIZE (0 means default).
 143    Objects start on multiples of ALIGNMENT (0 means use default).
 144    CHUNKFUN is the function to use to allocate chunks,
 145    and FREEFUN the function to free them.
 146
 147    Return nonzero if successful, calls obstack_alloc_failed_handler if
 148    allocation fails.  */
 149
 150 int
 151 _obstack_begin (h, size, alignment, chunkfun, freefun)
 152      struct obstack *h;
 153      int size;
 154      int alignment;
 155 #if defined (__STDC__) && __STDC__
 156      POINTER (*chunkfun) (long);
 157      void (*freefun) (void *);
 158 #else
 159      POINTER (*chunkfun) ();
 160      void (*freefun) ();
 161 #endif
 162 {
 163   register struct _obstack_chunk *chunk; /* points to new chunk */
 164
 165   if (alignment == 0)
 166     alignment = (int) DEFAULT_ALIGNMENT;
 167   if (size == 0)
 168     /* Default size is what GNU malloc can fit in a 4096-byte block.  */
 169     {
 170       /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
 171          Use the values for range checking, because if range checking is off,
 172          the extra bytes won't be missed terribly, but if range checking is on
 173          and we used a larger request, a whole extra 4096 bytes would be
 174          allocated.
 175
 176          These number are irrelevant to the new GNU malloc.  I suspect it is
 177          less sensitive to the size of the request.  */
 178       int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
 179                     + 4 + DEFAULT_ROUNDING - 1)
 180                    & ~(DEFAULT_ROUNDING - 1));
 181       size = 4096 - extra;
 182     }
 183
 184 #if defined (__STDC__) && __STDC__
 185   h->chunkfun = (struct _obstack_chunk * (*)(void *, long)) chunkfun;
 186   h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
 187 #else
 188   h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
 189   h->freefun = freefun;
 190 #endif
 191   h->chunk_size = size;
 192   h->alignment_mask = alignment - 1;
 193   h->use_extra_arg = 0;
 194
 195   chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
 196   if (!chunk)
 197     (*obstack_alloc_failed_handler) ();
 198   h->next_free = h->object_base = chunk->contents;
 199   h->chunk_limit = chunk->limit
 200     = (char *) chunk + h->chunk_size;
 201   chunk->prev = 0;
 202   /* The initial chunk now contains no empty object.  */
 203   h->maybe_empty_object = 0;
 204   h->alloc_failed = 0;
 205   return 1;
 206 }
 207
 208 int
 209 _obstack_begin_1 (h, size, alignment, chunkfun, freefun, arg)
 210      struct obstack *h;
 211      int size;
 212      int alignment;
 213 #if defined (__STDC__) && __STDC__
 214      POINTER (*chunkfun) (POINTER, long);
 215      void (*freefun) (POINTER, POINTER);
 216 #else
 217      POINTER (*chunkfun) ();
 218      void (*freefun) ();
 219 #endif
 220      POINTER arg;
 221 {
 222   register struct _obstack_chunk *chunk; /* points to new chunk */
 223
 224   if (alignment == 0)
 225     alignment = (int) DEFAULT_ALIGNMENT;
 226   if (size == 0)
 227     /* Default size is what GNU malloc can fit in a 4096-byte block.  */
 228     {
 229       /* 12 is sizeof (mhead) and 4 is EXTRA from GNU malloc.
 230          Use the values for range checking, because if range checking is off,
 231          the extra bytes won't be missed terribly, but if range checking is on
 232          and we used a larger request, a whole extra 4096 bytes would be
 233          allocated.
 234
 235          These number are irrelevant to the new GNU malloc.  I suspect it is
 236          less sensitive to the size of the request.  */
 237       int extra = ((((12 + DEFAULT_ROUNDING - 1) & ~(DEFAULT_ROUNDING - 1))
 238                     + 4 + DEFAULT_ROUNDING - 1)
 239                    & ~(DEFAULT_ROUNDING - 1));
 240       size = 4096 - extra;
 241     }
 242
 243 #if defined(__STDC__) && __STDC__
 244   h->chunkfun = (struct _obstack_chunk * (*)(void *,long)) chunkfun;
 245   h->freefun = (void (*) (void *, struct _obstack_chunk *)) freefun;
 246 #else
 247   h->chunkfun = (struct _obstack_chunk * (*)()) chunkfun;
 248   h->freefun = freefun;
 249 #endif
 250   h->chunk_size = size;
 251   h->alignment_mask = alignment - 1;
 252   h->extra_arg = arg;
 253   h->use_extra_arg = 1;
 254
 255   chunk = h->chunk = CALL_CHUNKFUN (h, h -> chunk_size);
 256   if (!chunk)
 257     (*obstack_alloc_failed_handler) ();
 258   h->next_free = h->object_base = chunk->contents;
 259   h->chunk_limit = chunk->limit
 260     = (char *) chunk + h->chunk_size;
 261   chunk->prev = 0;
 262   /* The initial chunk now contains no empty object.  */
 263   h->maybe_empty_object = 0;
 264   h->alloc_failed = 0;
 265   return 1;
 266 }
 267
 268 /* Allocate a new current chunk for the obstack *H
 269    on the assumption that LENGTH bytes need to be added
 270    to the current object, or a new object of length LENGTH allocated.
 271    Copies any partial object from the end of the old chunk
 272    to the beginning of the new one.  */
 273
 274 void
 275 _obstack_newchunk (h, length)
 276      struct obstack *h;
 277      int length;
 278 {
 279   register struct _obstack_chunk *old_chunk = h->chunk;
 280   register struct _obstack_chunk *new_chunk;
 281   register long new_size;
 282   register long obj_size = h->next_free - h->object_base;
 283   register long i;
 284   long already;
 285
 286   /* Compute size for new chunk.  */
 287   new_size = (obj_size + length) + (obj_size >> 3) + 100;
 288   if (new_size < h->chunk_size)
 289     new_size = h->chunk_size;
 290
 291   /* Allocate and initialize the new chunk.  */
 292   new_chunk = CALL_CHUNKFUN (h, new_size);
 293   if (!new_chunk)
 294     (*obstack_alloc_failed_handler) ();
 295   h->chunk = new_chunk;
 296   new_chunk->prev = old_chunk;
 297   new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
 298
 299   /* Move the existing object to the new chunk.
 300      Word at a time is fast and is safe if the object
 301      is sufficiently aligned.  */
 302   if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
 303     {
 304       for (i = obj_size / sizeof (COPYING_UNIT) - 1;
 305            i >= 0; i--)
 306         ((COPYING_UNIT *)new_chunk->contents)[i]
 307           = ((COPYING_UNIT *)h->object_base)[i];
 308       /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
 309          but that can cross a page boundary on a machine
 310          which does not do strict alignment for COPYING_UNITS.  */
 311       already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
 312     }
 313   else
 314     already = 0;
 315   /* Copy remaining bytes one by one.  */
 316   for (i = already; i < obj_size; i++)
 317     new_chunk->contents[i] = h->object_base[i];
 318
 319   /* If the object just copied was the only data in OLD_CHUNK,
 320      free that chunk and remove it from the chain.
 321      But not if that chunk might contain an empty object.  */
 322   if (h->object_base == old_chunk->contents && ! h->maybe_empty_object)
 323     {
 324       new_chunk->prev = old_chunk->prev;
 325       CALL_FREEFUN (h, old_chunk);
 326     }
 327
 328   h->object_base = new_chunk->contents;
 329   h->next_free = h->object_base + obj_size;
 330   /* The new chunk certainly contains no empty object yet.  */
 331   h->maybe_empty_object = 0;
 332 }
 333
 334 /* Return nonzero if object OBJ has been allocated from obstack H.
 335    This is here for debugging.
 336    If you use it in a program, you are probably losing.  */
 337
 338 #if defined (__STDC__) && __STDC__
 339 /* Suppress -Wmissing-prototypes warning.  We don't want to declare this in
 340    obstack.h because it is just for debugging.  */
 341 int _obstack_allocated_p (struct obstack *h, POINTER obj);
 342 #endif
 343
 344 int
 345 _obstack_allocated_p (h, obj)
 346      struct obstack *h;
 347      POINTER obj;
 348 {
 349   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 350   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 351
 352   lp = (h)->chunk;
 353   /* We use >= rather than > since the object cannot be exactly at
 354      the beginning of the chunk but might be an empty object exactly
 355      at the end of an adjacent chunk.  */
 356   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 357     {
 358       plp = lp->prev;
 359       lp = plp;
 360     }
 361   return lp != 0;
 362 }
 363 \f
 364 /* Free objects in obstack H, including OBJ and everything allocate
 365    more recently than OBJ.  If OBJ is zero, free everything in H.  */
 366
 367 #undef obstack_free
 368
 369 /* This function has two names with identical definitions.
 370    This is the first one, called from non-ANSI code.  */
 371
 372 void
 373 _obstack_free (h, obj)
 374      struct obstack *h;
 375      POINTER obj;
 376 {
 377   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 378   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 379
 380   lp = h->chunk;
 381   /* We use >= because there cannot be an object at the beginning of a chunk.
 382      But there can be an empty object at that address
 383      at the end of another chunk.  */
 384   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 385     {
 386       plp = lp->prev;
 387       CALL_FREEFUN (h, lp);
 388       lp = plp;
 389       /* If we switch chunks, we can't tell whether the new current
 390          chunk contains an empty object, so assume that it may.  */
 391       h->maybe_empty_object = 1;
 392     }
 393   if (lp)
 394     {
 395       h->object_base = h->next_free = (char *) (obj);
 396       h->chunk_limit = lp->limit;
 397       h->chunk = lp;
 398     }
 399   else if (obj != 0)
 400     /* obj is not in any of the chunks! */
 401     abort ();
 402 }
 403
 404 /* This function is used from ANSI code.  */
 405
 406 void
 407 obstack_free (h, obj)
 408      struct obstack *h;
 409      POINTER obj;
 410 {
 411   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 412   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 413
 414   lp = h->chunk;
 415   /* We use >= because there cannot be an object at the beginning of a chunk.
 416      But there can be an empty object at that address
 417      at the end of another chunk.  */
 418   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 419     {
 420       plp = lp->prev;
 421       CALL_FREEFUN (h, lp);
 422       lp = plp;
 423       /* If we switch chunks, we can't tell whether the new current
 424          chunk contains an empty object, so assume that it may.  */
 425       h->maybe_empty_object = 1;
 426     }
 427   if (lp)
 428     {
 429       h->object_base = h->next_free = (char *) (obj);
 430       h->chunk_limit = lp->limit;
 431       h->chunk = lp;
 432     }
 433   else if (obj != 0)
 434     /* obj is not in any of the chunks! */
 435     abort ();
 436 }
 437 \f
 438 int
 439 _obstack_memory_used (h)
 440      struct obstack *h;
 441 {
 442   register struct _obstack_chunk* lp;
 443   register int nbytes = 0;
 444
 445   for (lp = h->chunk; lp != 0; lp = lp->prev)
 446     {
 447       nbytes += lp->limit - (char *) lp;
 448     }
 449   return nbytes;
 450 }
 451 \f
 452 /* Define the error handler.  */
 453 #ifndef _
 454 # ifdef HAVE_LIBINTL_H
 455 #  include <libintl.h>
 456 #  ifndef _
 457 #   define _(Str) gettext (Str)
 458 #  endif
 459 # else
 460 #  define _(Str) (Str)
 461 # endif
 462 #endif
 463 #if defined _LIBC && defined USE_IN_LIBIO
 464 # include <libio/iolibio.h>
 465 # define fputs(s, f) _IO_fputs (s, f)
 466 #endif
 467
 468 static void
 469 print_and_abort ()
 470 {
 471   fputs (_("memory exhausted\n"), stderr);
 472   exit (obstack_exit_failure);
 473 }
 474 \f
 475 #if 0
 476 /* These are now turned off because the applications do not use it
 477    and it uses bcopy via obstack_grow, which causes trouble on sysV.  */
 478
 479 /* Now define the functional versions of the obstack macros.
 480    Define them to simply use the corresponding macros to do the job.  */
 481
 482 #if defined (__STDC__) && __STDC__
 483 /* These function definitions do not work with non-ANSI preprocessors;
 484    they won't pass through the macro names in parentheses.  */
 485
 486 /* The function names appear in parentheses in order to prevent
 487    the macro-definitions of the names from being expanded there.  */
 488
 489 POINTER (obstack_base) (obstack)
 490      struct obstack *obstack;
 491 {
 492   return obstack_base (obstack);
 493 }
 494
 495 POINTER (obstack_next_free) (obstack)
 496      struct obstack *obstack;
 497 {
 498   return obstack_next_free (obstack);
 499 }
 500
 501 int (obstack_object_size) (obstack)
 502      struct obstack *obstack;
 503 {
 504   return obstack_object_size (obstack);
 505 }
 506
 507 int (obstack_room) (obstack)
 508      struct obstack *obstack;
 509 {
 510   return obstack_room (obstack);
 511 }
 512
 513 int (obstack_make_room) (obstack, length)
 514      struct obstack *obstack;
 515      int length;
 516 {
 517   return obstack_make_room (obstack, length);
 518 }
 519
 520 void (obstack_grow) (obstack, pointer, length)
 521      struct obstack *obstack;
 522      POINTER pointer;
 523      int length;
 524 {
 525   obstack_grow (obstack, pointer, length);
 526 }
 527
 528 void (obstack_grow0) (obstack, pointer, length)
 529      struct obstack *obstack;
 530      POINTER pointer;
 531      int length;
 532 {
 533   obstack_grow0 (obstack, pointer, length);
 534 }
 535
 536 void (obstack_1grow) (obstack, character)
 537      struct obstack *obstack;
 538      int character;
 539 {
 540   obstack_1grow (obstack, character);
 541 }
 542
 543 void (obstack_blank) (obstack, length)
 544      struct obstack *obstack;
 545      int length;
 546 {
 547   obstack_blank (obstack, length);
 548 }
 549
 550 void (obstack_1grow_fast) (obstack, character)
 551      struct obstack *obstack;
 552      int character;
 553 {
 554   obstack_1grow_fast (obstack, character);
 555 }
 556
 557 void (obstack_blank_fast) (obstack, length)
 558      struct obstack *obstack;
 559      int length;
 560 {
 561   obstack_blank_fast (obstack, length);
 562 }
 563
 564 POINTER (obstack_finish) (obstack)
 565      struct obstack *obstack;
 566 {
 567   return obstack_finish (obstack);
 568 }
 569
 570 POINTER (obstack_alloc) (obstack, length)
 571      struct obstack *obstack;
 572      int length;
 573 {
 574   return obstack_alloc (obstack, length);
 575 }
 576
 577 POINTER (obstack_copy) (obstack, pointer, length)
 578      struct obstack *obstack;
 579      POINTER pointer;
 580      int length;
 581 {
 582   return obstack_copy (obstack, pointer, length);
 583 }
 584
 585 POINTER (obstack_copy0) (obstack, pointer, length)
 586      struct obstack *obstack;
 587      POINTER pointer;
 588      int length;
 589 {
 590   return obstack_copy0 (obstack, pointer, length);
 591 }
 592
 593 #endif /* __STDC__ */
 594
 595 #endif /* 0 */
 596
 597 #endif  /* !ELIDE_CODE */