lib/obstack.c

   1 /* obstack.c - subroutines used implicitly by object stack macros
   2    Copyright (C) 1988-1994,96,97,98,99,2000 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   char *object_base;
 286
 287   /* Compute size for new chunk.  */
 288   new_size = (obj_size + length) + (obj_size >> 3) + h->alignment_mask + 100;
 289   if (new_size < h->chunk_size)
 290     new_size = h->chunk_size;
 291
 292   /* Allocate and initialize the new chunk.  */
 293   new_chunk = CALL_CHUNKFUN (h, new_size);
 294   if (!new_chunk)
 295     (*obstack_alloc_failed_handler) ();
 296   h->chunk = new_chunk;
 297   new_chunk->prev = old_chunk;
 298   new_chunk->limit = h->chunk_limit = (char *) new_chunk + new_size;
 299
 300   /* Compute an aligned object_base in the new chunk */
 301   object_base =
 302     __INT_TO_PTR ((__PTR_TO_INT (new_chunk->contents) + h->alignment_mask)
 303                   & ~ (h->alignment_mask));
 304
 305   /* Move the existing object to the new chunk.
 306      Word at a time is fast and is safe if the object
 307      is sufficiently aligned.  */
 308   if (h->alignment_mask + 1 >= DEFAULT_ALIGNMENT)
 309     {
 310       for (i = obj_size / sizeof (COPYING_UNIT) - 1;
 311            i >= 0; i--)
 312         ((COPYING_UNIT *)object_base)[i]
 313           = ((COPYING_UNIT *)h->object_base)[i];
 314       /* We used to copy the odd few remaining bytes as one extra COPYING_UNIT,
 315          but that can cross a page boundary on a machine
 316          which does not do strict alignment for COPYING_UNITS.  */
 317       already = obj_size / sizeof (COPYING_UNIT) * sizeof (COPYING_UNIT);
 318     }
 319   else
 320     already = 0;
 321   /* Copy remaining bytes one by one.  */
 322   for (i = already; i < obj_size; i++)
 323     object_base[i] = h->object_base[i];
 324
 325   /* If the object just copied was the only data in OLD_CHUNK,
 326      free that chunk and remove it from the chain.
 327      But not if that chunk might contain an empty object.  */
 328   if (h->object_base == old_chunk->contents && ! h->maybe_empty_object)
 329     {
 330       new_chunk->prev = old_chunk->prev;
 331       CALL_FREEFUN (h, old_chunk);
 332     }
 333
 334   h->object_base = object_base;
 335   h->next_free = h->object_base + obj_size;
 336   /* The new chunk certainly contains no empty object yet.  */
 337   h->maybe_empty_object = 0;
 338 }
 339
 340 /* Return nonzero if object OBJ has been allocated from obstack H.
 341    This is here for debugging.
 342    If you use it in a program, you are probably losing.  */
 343
 344 # if defined (__STDC__) && __STDC__
 345 /* Suppress -Wmissing-prototypes warning.  We don't want to declare this in
 346    obstack.h because it is just for debugging.  */
 347 int _obstack_allocated_p (struct obstack *h, POINTER obj);
 348 # endif
 349
 350 int
 351 _obstack_allocated_p (h, obj)
 352      struct obstack *h;
 353      POINTER obj;
 354 {
 355   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 356   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 357
 358   lp = (h)->chunk;
 359   /* We use >= rather than > since the object cannot be exactly at
 360      the beginning of the chunk but might be an empty object exactly
 361      at the end of an adjacent chunk.  */
 362   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 363     {
 364       plp = lp->prev;
 365       lp = plp;
 366     }
 367   return lp != 0;
 368 }
 369 \f
 370 /* Free objects in obstack H, including OBJ and everything allocate
 371    more recently than OBJ.  If OBJ is zero, free everything in H.  */
 372
 373 # undef obstack_free
 374
 375 /* This function has two names with identical definitions.
 376    This is the first one, called from non-ANSI code.  */
 377
 378 void
 379 _obstack_free (h, obj)
 380      struct obstack *h;
 381      POINTER obj;
 382 {
 383   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 384   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 385
 386   lp = h->chunk;
 387   /* We use >= because there cannot be an object at the beginning of a chunk.
 388      But there can be an empty object at that address
 389      at the end of another chunk.  */
 390   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 391     {
 392       plp = lp->prev;
 393       CALL_FREEFUN (h, lp);
 394       lp = plp;
 395       /* If we switch chunks, we can't tell whether the new current
 396          chunk contains an empty object, so assume that it may.  */
 397       h->maybe_empty_object = 1;
 398     }
 399   if (lp)
 400     {
 401       h->object_base = h->next_free = (char *) (obj);
 402       h->chunk_limit = lp->limit;
 403       h->chunk = lp;
 404     }
 405   else if (obj != 0)
 406     /* obj is not in any of the chunks! */
 407     abort ();
 408 }
 409
 410 /* This function is used from ANSI code.  */
 411
 412 void
 413 obstack_free (h, obj)
 414      struct obstack *h;
 415      POINTER obj;
 416 {
 417   register struct _obstack_chunk *lp;   /* below addr of any objects in this chunk */
 418   register struct _obstack_chunk *plp;  /* point to previous chunk if any */
 419
 420   lp = h->chunk;
 421   /* We use >= because there cannot be an object at the beginning of a chunk.
 422      But there can be an empty object at that address
 423      at the end of another chunk.  */
 424   while (lp != 0 && ((POINTER) lp >= obj || (POINTER) (lp)->limit < obj))
 425     {
 426       plp = lp->prev;
 427       CALL_FREEFUN (h, lp);
 428       lp = plp;
 429       /* If we switch chunks, we can't tell whether the new current
 430          chunk contains an empty object, so assume that it may.  */
 431       h->maybe_empty_object = 1;
 432     }
 433   if (lp)
 434     {
 435       h->object_base = h->next_free = (char *) (obj);
 436       h->chunk_limit = lp->limit;
 437       h->chunk = lp;
 438     }
 439   else if (obj != 0)
 440     /* obj is not in any of the chunks! */
 441     abort ();
 442 }
 443 \f
 444 int
 445 _obstack_memory_used (h)
 446      struct obstack *h;
 447 {
 448   register struct _obstack_chunk* lp;
 449   register int nbytes = 0;
 450
 451   for (lp = h->chunk; lp != 0; lp = lp->prev)
 452     {
 453       nbytes += lp->limit - (char *) lp;
 454     }
 455   return nbytes;
 456 }
 457 \f
 458 /* Define the error handler.  */
 459 # ifndef _
 460 #  if defined HAVE_LIBINTL_H || defined _LIBC
 461 #   include <libintl.h>
 462 #   ifndef _
 463 #    define _(Str) gettext (Str)
 464 #   endif
 465 #  else
 466 #   define _(Str) (Str)
 467 #  endif
 468 # endif
 469 # if defined _LIBC && defined USE_IN_LIBIO
 470 #  include <libio/iolibio.h>
 471 #  define fputs(s, f) _IO_fputs (s, f)
 472 # endif
 473
 474 static void
 475 print_and_abort ()
 476 {
 477   fputs (_("memory exhausted"), stderr);
 478   fputc ('\n', stderr);
 479   exit (obstack_exit_failure);
 480 }
 481 \f
 482 # if 0
 483 /* These are now turned off because the applications do not use it
 484    and it uses bcopy via obstack_grow, which causes trouble on sysV.  */
 485
 486 /* Now define the functional versions of the obstack macros.
 487    Define them to simply use the corresponding macros to do the job.  */
 488
 489 #  if defined (__STDC__) && __STDC__
 490 /* These function definitions do not work with non-ANSI preprocessors;
 491    they won't pass through the macro names in parentheses.  */
 492
 493 /* The function names appear in parentheses in order to prevent
 494    the macro-definitions of the names from being expanded there.  */
 495
 496 POINTER (obstack_base) (obstack)
 497      struct obstack *obstack;
 498 {
 499   return obstack_base (obstack);
 500 }
 501
 502 POINTER (obstack_next_free) (obstack)
 503      struct obstack *obstack;
 504 {
 505   return obstack_next_free (obstack);
 506 }
 507
 508 int (obstack_object_size) (obstack)
 509      struct obstack *obstack;
 510 {
 511   return obstack_object_size (obstack);
 512 }
 513
 514 int (obstack_room) (obstack)
 515      struct obstack *obstack;
 516 {
 517   return obstack_room (obstack);
 518 }
 519
 520 int (obstack_make_room) (obstack, length)
 521      struct obstack *obstack;
 522      int length;
 523 {
 524   return obstack_make_room (obstack, length);
 525 }
 526
 527 void (obstack_grow) (obstack, data, length)
 528      struct obstack *obstack;
 529      const POINTER data;
 530      int length;
 531 {
 532   obstack_grow (obstack, data, length);
 533 }
 534
 535 void (obstack_grow0) (obstack, data, length)
 536      struct obstack *obstack;
 537      const POINTER data;
 538      int length;
 539 {
 540   obstack_grow0 (obstack, data, length);
 541 }
 542
 543 void (obstack_1grow) (obstack, character)
 544      struct obstack *obstack;
 545      int character;
 546 {
 547   obstack_1grow (obstack, character);
 548 }
 549
 550 void (obstack_blank) (obstack, length)
 551      struct obstack *obstack;
 552      int length;
 553 {
 554   obstack_blank (obstack, length);
 555 }
 556
 557 void (obstack_1grow_fast) (obstack, character)
 558      struct obstack *obstack;
 559      int character;
 560 {
 561   obstack_1grow_fast (obstack, character);
 562 }
 563
 564 void (obstack_blank_fast) (obstack, length)
 565      struct obstack *obstack;
 566      int length;
 567 {
 568   obstack_blank_fast (obstack, length);
 569 }
 570
 571 POINTER (obstack_finish) (obstack)
 572      struct obstack *obstack;
 573 {
 574   return obstack_finish (obstack);
 575 }
 576
 577 POINTER (obstack_alloc) (obstack, length)
 578      struct obstack *obstack;
 579      int length;
 580 {
 581   return obstack_alloc (obstack, length);
 582 }
 583
 584 POINTER (obstack_copy) (obstack, address, length)
 585      struct obstack *obstack;
 586      const POINTER address;
 587      int length;
 588 {
 589   return obstack_copy (obstack, address, length);
 590 }
 591
 592 POINTER (obstack_copy0) (obstack, address, length)
 593      struct obstack *obstack;
 594      const POINTER address;
 595      int length;
 596 {
 597   return obstack_copy0 (obstack, address, length);
 598 }
 599
 600 #  endif /* __STDC__ */
 601
 602 # endif /* 0 */
 603
 604 #endif  /* !ELIDE_CODE */