libiberty/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
   5    NOTE: This source is derived from an old version taken from the GNU C
   6    Library (glibc).
   7
   8    This program is free software; you can redistribute it and/or modify it
   9    under the terms of the GNU General Public License as published by the
  10    Free Software Foundation; either version 2, or (at your option) any
  11    later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  21    USA.  */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include "obstack.h"
  28
  29 /* NOTE BEFORE MODIFYING THIS FILE: This version number must be
  30    incremented whenever callers compiled using an old obstack.h can no
  31    longer properly call the functions in this obstack.c.  */
  32 #define OBSTACK_INTERFACE_VERSION 1
  33
  34 /* Comment out all this code if we are using the GNU C Library, and are not
  35    actually compiling the library itself, and the installed library
  36    supports the same library interface we do.  This code is part of the GNU
  37    C Library, but also included in many other GNU distributions.  Compiling
  38    and linking in this code is a waste when using the GNU C library
  39    (especially if it is a shared library).  Rather than having every GNU
  40    program understand `configure --with-gnu-libc' and omit the object
  41    files, it is simpler to just do this in the source for each such file.  */
  42
  43 #include <stdio.h>              /* Random thing to get __GNU_LIBRARY__.  */
  44 #if !defined (_LIBC) && defined (__GNU_LIBRARY__) && __GNU_LIBRARY__ > 1
  45 #include <gnu-versions.h>
  46 #if _GNU_OBSTACK_INTERFACE_VERSION == OBSTACK_INTERFACE_VERSION
  47 #define ELIDE_CODE
  48 #endif
  49 #endif
  50
  51
  52 #ifndef ELIDE_CODE
  53
  54
  55 #if defined (__STDC__) && __STDC__
  56 #define POINTER void *
  57 #else
  58 #define POINTER char *
  59 #endif
  60
  61 /* Determine default alignment.  */
  62 struct fooalign {char x; double d;};
  63 #define DEFAULT_ALIGNMENT  \
  64   ((PTR_INT_TYPE) ((char *) &((struct fooalign *) 0)->d - (char *) 0))
  65 /* If malloc were really smart, it would round addresses to DEFAULT_ALIGNMENT.
  66    But in fact it might be less smart and round addresses to as much as
  67    DEFAULT_ROUNDING.  So we prepare for it to do that.  */
  68 union fooround {long x; double d;};
  69 #define DEFAULT_ROUNDING (sizeof (union fooround))
  70
  71 /* When we copy a long block of data, this is the unit to do it with.
  72    On some machines, copying successive ints does not work;
  73    in such a case, redefine COPYING_UNIT to `long' (if that works)
  74    or `char' as a last resort.  */
  75 #ifndef COPYING_UNIT
  76 #define COPYING_UNIT int
  77 #endif
  78
  79
  80 /* The functions allocating more room by calling `obstack_chunk_alloc'
  81    jump to the handler pointed to by `obstack_alloc_failed_handler'.
  82    This variable by default points to the internal function
  83    `print_and_abort'.  */
  84 #if defined (__STDC__) && __STDC__
  85 static void print_and_abort (void);
  86 void (*obstack_alloc_failed_handler) (void) = print_and_abort;
  87 #else
  88 static void print_and_abort ();
  89 void (*obstack_alloc_failed_handler) () = print_and_abort;
  90 #endif
  91
  92 /* Exit value used when `print_and_abort' is used.  */
  93 #if defined __GNU_LIBRARY__ || defined HAVE_STDLIB_H
  94 #include <stdlib.h>
  95 #endif
  96 #ifndef EXIT_FAILURE
  97 #define EXIT_FAILURE 1
  98 #endif
  99 int obstack_exit_failure = EXIT_FAILURE;
 100
 101 /* The non-GNU-C macros copy the obstack into this global variable
 102    to avoid multiple evaluation.  */
 103
 104 struct obstack *_obstack;
 105
 106 /* Define a macro that either calls functions with the traditional malloc/free
 107    calling interface, or calls functions with the mmalloc/mfree interface
 108    (that adds an extra first argument), based on the state of use_extra_arg.
 109    For free, do not use ?:, since some compilers, like the MIPS compilers,
 110    do not allow (expr) ? void : void.  */
 111
 112 #if defined (__STDC__) && __STDC__
 113 #define CALL_CHUNKFUN(h, size) \
 114   (((h) -> use_extra_arg) \
 115    ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
 116    : (*(struct _obstack_chunk *(*) (long)) (h)->chunkfun) ((size)))
 117
 118 #define CALL_FREEFUN(h, old_chunk) \
 119   do { \
 120     if ((h) -> use_extra_arg) \
 121       (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
 122     else \
 123       (*(void (*) (void *)) (h)->freefun) ((old_chunk)); \
 124   } while (0)
 125 #else
 126 #define CALL_CHUNKFUN(h, size) \
 127   (((h) -> use_extra_arg) \
 128    ? (*(h)->chunkfun) ((h)->extra_arg, (size)) \
 129    : (*(struct _obstack_chunk *(*) ()) (h)->chunkfun) ((size)))
 130
 131 #define CALL_FREEFUN(h, old_chunk) \
 132   do { \
 133     if ((h) -> use_extra_arg) \
 134       (*(h)->freefun) ((h)->extra_arg, (old_chunk)); \
 135     else \
 136       (*(void (*) ()) (h)->freefun) ((old_chunk)); \
 137   } while (0)
 138 #endif
 139
 140 \f
 141 /* Initialize an obstack H for use.  Specify chunk size SIZE (0 means default).
 142    Objects start on multiples of ALIGNMENT (0 means use default).
 143    CHUNKFUN is the function to use to allocate chunks,
 144    and FREEFUN the function to free them.
 145
 146    Return nonzero if successful, zero if out of memory.
 147    To recover from an out of memory error,
 148    free up some memory, then call this again.  */
 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
 464 static void
 465 print_and_abort ()
 466 {
 467   fputs (_("memory exhausted\n"), stderr);
 468   exit (obstack_exit_failure);
 469 }
 470 \f
 471 #if 0
 472 /* These are now turned off because the applications do not use it
 473    and it uses bcopy via obstack_grow, which causes trouble on sysV.  */
 474
 475 /* Now define the functional versions of the obstack macros.
 476    Define them to simply use the corresponding macros to do the job.  */
 477
 478 #if defined (__STDC__) && __STDC__
 479 /* These function definitions do not work with non-ANSI preprocessors;
 480    they won't pass through the macro names in parentheses.  */
 481
 482 /* The function names appear in parentheses in order to prevent
 483    the macro-definitions of the names from being expanded there.  */
 484
 485 POINTER (obstack_base) (obstack)
 486      struct obstack *obstack;
 487 {
 488   return obstack_base (obstack);
 489 }
 490
 491 POINTER (obstack_next_free) (obstack)
 492      struct obstack *obstack;
 493 {
 494   return obstack_next_free (obstack);
 495 }
 496
 497 int (obstack_object_size) (obstack)
 498      struct obstack *obstack;
 499 {
 500   return obstack_object_size (obstack);
 501 }
 502
 503 int (obstack_room) (obstack)
 504      struct obstack *obstack;
 505 {
 506   return obstack_room (obstack);
 507 }
 508
 509 int (obstack_make_room) (obstack, length)
 510      struct obstack *obstack;
 511      int length;
 512 {
 513   return obstack_make_room (obstack, length);
 514 }
 515
 516 void (obstack_grow) (obstack, pointer, length)
 517      struct obstack *obstack;
 518      POINTER pointer;
 519      int length;
 520 {
 521   obstack_grow (obstack, pointer, length);
 522 }
 523
 524 void (obstack_grow0) (obstack, pointer, length)
 525      struct obstack *obstack;
 526      POINTER pointer;
 527      int length;
 528 {
 529   obstack_grow0 (obstack, pointer, length);
 530 }
 531
 532 void (obstack_1grow) (obstack, character)
 533      struct obstack *obstack;
 534      int character;
 535 {
 536   obstack_1grow (obstack, character);
 537 }
 538
 539 void (obstack_blank) (obstack, length)
 540      struct obstack *obstack;
 541      int length;
 542 {
 543   obstack_blank (obstack, length);
 544 }
 545
 546 void (obstack_1grow_fast) (obstack, character)
 547      struct obstack *obstack;
 548      int character;
 549 {
 550   obstack_1grow_fast (obstack, character);
 551 }
 552
 553 void (obstack_blank_fast) (obstack, length)
 554      struct obstack *obstack;
 555      int length;
 556 {
 557   obstack_blank_fast (obstack, length);
 558 }
 559
 560 POINTER (obstack_finish) (obstack)
 561      struct obstack *obstack;
 562 {
 563   return obstack_finish (obstack);
 564 }
 565
 566 POINTER (obstack_alloc) (obstack, length)
 567      struct obstack *obstack;
 568      int length;
 569 {
 570   return obstack_alloc (obstack, length);
 571 }
 572
 573 POINTER (obstack_copy) (obstack, pointer, length)
 574      struct obstack *obstack;
 575      POINTER pointer;
 576      int length;
 577 {
 578   return obstack_copy (obstack, pointer, length);
 579 }
 580
 581 POINTER (obstack_copy0) (obstack, pointer, length)
 582      struct obstack *obstack;
 583      POINTER pointer;
 584      int length;
 585 {
 586   return obstack_copy0 (obstack, pointer, length);
 587 }
 588
 589 #endif /* __STDC__ */
 590
 591 #endif /* 0 */
 592
 593 #endif  /* !ELIDE_CODE */