gcc/ggc-common.c

   1 /* Simple garbage collection for the GNU compiler.
   2    Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 /* Generic garbage collection (GC) functions and data, not specific to
  23    any particular GC implementation.  */
  24
  25 #include "config.h"
  26 #include "system.h"
  27 #include "coretypes.h"
  28 #include "hashtab.h"
  29 #include "ggc.h"
  30 #include "toplev.h"
  31 #include "params.h"
  32 #include "hosthooks.h"
  33 #include "hosthooks-def.h"
  34
  35 #ifdef HAVE_SYS_RESOURCE_H
  36 # include <sys/resource.h>
  37 #endif
  38
  39 #ifdef HAVE_MMAP_FILE
  40 # include <sys/mman.h>
  41 # ifdef HAVE_MINCORE
  42 /* This is on Solaris.  */
  43 #  include <sys/types.h>
  44 # endif
  45 #endif
  46
  47 #ifndef MAP_FAILED
  48 # define MAP_FAILED ((void *)-1)
  49 #endif
  50
  51 #ifdef ENABLE_VALGRIND_CHECKING
  52 # ifdef HAVE_VALGRIND_MEMCHECK_H
  53 #  include <valgrind/memcheck.h>
  54 # elif defined HAVE_MEMCHECK_H
  55 #  include <memcheck.h>
  56 # else
  57 #  include <valgrind.h>
  58 # endif
  59 #else
  60 /* Avoid #ifdef:s when we can help it.  */
  61 #define VALGRIND_DISCARD(x)
  62 #endif
  63
  64 /* When set, ggc_collect will do collection.  */
  65 bool ggc_force_collect;
  66
  67 /* Statistics about the allocation.  */
  68 static ggc_statistics *ggc_stats;
  69
  70 struct traversal_state;
  71
  72 static int ggc_htab_delete (void **, void *);
  73 static hashval_t saving_htab_hash (const void *);
  74 static int saving_htab_eq (const void *, const void *);
  75 static int call_count (void **, void *);
  76 static int call_alloc (void **, void *);
  77 static int compare_ptr_data (const void *, const void *);
  78 static void relocate_ptrs (void *, void *);
  79 static void write_pch_globals (const struct ggc_root_tab * const *tab,
  80                                struct traversal_state *state);
  81 static double ggc_rlimit_bound (double);
  82
  83 /* Maintain global roots that are preserved during GC.  */
  84
  85 /* Process a slot of an htab by deleting it if it has not been marked.  */
  86
  87 static int
  88 ggc_htab_delete (void **slot, void *info)
  89 {
  90   const struct ggc_cache_tab *r = (const struct ggc_cache_tab *) info;
  91
  92   if (! (*r->marked_p) (*slot))
  93     htab_clear_slot (*r->base, slot);
  94   else
  95     (*r->cb) (*slot);
  96
  97   return 1;
  98 }
  99
 100 /* Iterate through all registered roots and mark each element.  */
 101
 102 void
 103 ggc_mark_roots (void)
 104 {
 105   const struct ggc_root_tab *const *rt;
 106   const struct ggc_root_tab *rti;
 107   const struct ggc_cache_tab *const *ct;
 108   const struct ggc_cache_tab *cti;
 109   size_t i;
 110
 111   for (rt = gt_ggc_deletable_rtab; *rt; rt++)
 112     for (rti = *rt; rti->base != NULL; rti++)
 113       memset (rti->base, 0, rti->stride);
 114
 115   for (rt = gt_ggc_rtab; *rt; rt++)
 116     for (rti = *rt; rti->base != NULL; rti++)
 117       for (i = 0; i < rti->nelt; i++)
 118         (*rti->cb)(*(void **)((char *)rti->base + rti->stride * i));
 119
 120   ggc_mark_stringpool ();
 121
 122   /* Now scan all hash tables that have objects which are to be deleted if
 123      they are not already marked.  */
 124   for (ct = gt_ggc_cache_rtab; *ct; ct++)
 125     for (cti = *ct; cti->base != NULL; cti++)
 126       if (*cti->base)
 127         {
 128           ggc_set_mark (*cti->base);
 129           htab_traverse_noresize (*cti->base, ggc_htab_delete, (void *) cti);
 130           ggc_set_mark ((*cti->base)->entries);
 131         }
 132 }
 133
 134 /* Allocate a block of memory, then clear it.  */
 135 void *
 136 ggc_alloc_cleared_stat (size_t size MEM_STAT_DECL)
 137 {
 138   void *buf = ggc_alloc_stat (size PASS_MEM_STAT);
 139   memset (buf, 0, size);
 140   return buf;
 141 }
 142
 143 /* Resize a block of memory, possibly re-allocating it.  */
 144 void *
 145 ggc_realloc_stat (void *x, size_t size MEM_STAT_DECL)
 146 {
 147   void *r;
 148   size_t old_size;
 149
 150   if (x == NULL)
 151     return ggc_alloc_stat (size PASS_MEM_STAT);
 152
 153   old_size = ggc_get_size (x);
 154
 155   if (size <= old_size)
 156     {
 157       /* Mark the unwanted memory as unaccessible.  We also need to make
 158          the "new" size accessible, since ggc_get_size returns the size of
 159          the pool, not the size of the individually allocated object, the
 160          size which was previously made accessible.  Unfortunately, we
 161          don't know that previously allocated size.  Without that
 162          knowledge we have to lose some initialization-tracking for the
 163          old parts of the object.  An alternative is to mark the whole
 164          old_size as reachable, but that would lose tracking of writes
 165          after the end of the object (by small offsets).  Discard the
 166          handle to avoid handle leak.  */
 167       VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS ((char *) x + size,
 168                                                 old_size - size));
 169       VALGRIND_DISCARD (VALGRIND_MAKE_READABLE (x, size));
 170       return x;
 171     }
 172
 173   r = ggc_alloc_stat (size PASS_MEM_STAT);
 174
 175   /* Since ggc_get_size returns the size of the pool, not the size of the
 176      individually allocated object, we'd access parts of the old object
 177      that were marked invalid with the memcpy below.  We lose a bit of the
 178      initialization-tracking since some of it may be uninitialized.  */
 179   VALGRIND_DISCARD (VALGRIND_MAKE_READABLE (x, old_size));
 180
 181   memcpy (r, x, old_size);
 182
 183   /* The old object is not supposed to be used anymore.  */
 184   ggc_free (x);
 185
 186   return r;
 187 }
 188
 189 /* Like ggc_alloc_cleared, but performs a multiplication.  */
 190 void *
 191 ggc_calloc (size_t s1, size_t s2)
 192 {
 193   return ggc_alloc_cleared (s1 * s2);
 194 }
 195
 196 /* These are for splay_tree_new_ggc.  */
 197 void *
 198 ggc_splay_alloc (int sz, void *nl)
 199 {
 200   gcc_assert (!nl);
 201   return ggc_alloc (sz);
 202 }
 203
 204 void
 205 ggc_splay_dont_free (void * x ATTRIBUTE_UNUSED, void *nl)
 206 {
 207   gcc_assert (!nl);
 208 }
 209
 210 /* Print statistics that are independent of the collector in use.  */
 211 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
 212                   ? (x) \
 213                   : ((x) < 1024*1024*10 \
 214                      ? (x) / 1024 \
 215                      : (x) / (1024*1024))))
 216 #define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 217
 218 void
 219 ggc_print_common_statistics (FILE *stream ATTRIBUTE_UNUSED,
 220                              ggc_statistics *stats)
 221 {
 222   /* Set the pointer so that during collection we will actually gather
 223      the statistics.  */
 224   ggc_stats = stats;
 225
 226   /* Then do one collection to fill in the statistics.  */
 227   ggc_collect ();
 228
 229   /* At present, we don't really gather any interesting statistics.  */
 230
 231   /* Don't gather statistics any more.  */
 232   ggc_stats = NULL;
 233 }
 234 \f
 235 /* Functions for saving and restoring GCable memory to disk.  */
 236
 237 static htab_t saving_htab;
 238
 239 struct ptr_data
 240 {
 241   void *obj;
 242   void *note_ptr_cookie;
 243   gt_note_pointers note_ptr_fn;
 244   gt_handle_reorder reorder_fn;
 245   size_t size;
 246   void *new_addr;
 247 };
 248
 249 #define POINTER_HASH(x) (hashval_t)((long)x >> 3)
 250
 251 /* Register an object in the hash table.  */
 252
 253 int
 254 gt_pch_note_object (void *obj, void *note_ptr_cookie,
 255                     gt_note_pointers note_ptr_fn)
 256 {
 257   struct ptr_data **slot;
 258
 259   if (obj == NULL || obj == (void *) 1)
 260     return 0;
 261
 262   slot = (struct ptr_data **)
 263     htab_find_slot_with_hash (saving_htab, obj, POINTER_HASH (obj),
 264                               INSERT);
 265   if (*slot != NULL)
 266     {
 267       gcc_assert ((*slot)->note_ptr_fn == note_ptr_fn
 268                   && (*slot)->note_ptr_cookie == note_ptr_cookie);
 269       return 0;
 270     }
 271
 272   *slot = xcalloc (sizeof (struct ptr_data), 1);
 273   (*slot)->obj = obj;
 274   (*slot)->note_ptr_fn = note_ptr_fn;
 275   (*slot)->note_ptr_cookie = note_ptr_cookie;
 276   if (note_ptr_fn == gt_pch_p_S)
 277     (*slot)->size = strlen (obj) + 1;
 278   else
 279     (*slot)->size = ggc_get_size (obj);
 280   return 1;
 281 }
 282
 283 /* Register an object in the hash table.  */
 284
 285 void
 286 gt_pch_note_reorder (void *obj, void *note_ptr_cookie,
 287                      gt_handle_reorder reorder_fn)
 288 {
 289   struct ptr_data *data;
 290
 291   if (obj == NULL || obj == (void *) 1)
 292     return;
 293
 294   data = htab_find_with_hash (saving_htab, obj, POINTER_HASH (obj));
 295   gcc_assert (data && data->note_ptr_cookie == note_ptr_cookie);
 296
 297   data->reorder_fn = reorder_fn;
 298 }
 299
 300 /* Hash and equality functions for saving_htab, callbacks for htab_create.  */
 301
 302 static hashval_t
 303 saving_htab_hash (const void *p)
 304 {
 305   return POINTER_HASH (((struct ptr_data *)p)->obj);
 306 }
 307
 308 static int
 309 saving_htab_eq (const void *p1, const void *p2)
 310 {
 311   return ((struct ptr_data *)p1)->obj == p2;
 312 }
 313
 314 /* Handy state for the traversal functions.  */
 315
 316 struct traversal_state
 317 {
 318   FILE *f;
 319   struct ggc_pch_data *d;
 320   size_t count;
 321   struct ptr_data **ptrs;
 322   size_t ptrs_i;
 323 };
 324
 325 /* Callbacks for htab_traverse.  */
 326
 327 static int
 328 call_count (void **slot, void *state_p)
 329 {
 330   struct ptr_data *d = (struct ptr_data *)*slot;
 331   struct traversal_state *state = (struct traversal_state *)state_p;
 332
 333   ggc_pch_count_object (state->d, d->obj, d->size, d->note_ptr_fn == gt_pch_p_S);
 334   state->count++;
 335   return 1;
 336 }
 337
 338 static int
 339 call_alloc (void **slot, void *state_p)
 340 {
 341   struct ptr_data *d = (struct ptr_data *)*slot;
 342   struct traversal_state *state = (struct traversal_state *)state_p;
 343
 344   d->new_addr = ggc_pch_alloc_object (state->d, d->obj, d->size, d->note_ptr_fn == gt_pch_p_S);
 345   state->ptrs[state->ptrs_i++] = d;
 346   return 1;
 347 }
 348
 349 /* Callback for qsort.  */
 350
 351 static int
 352 compare_ptr_data (const void *p1_p, const void *p2_p)
 353 {
 354   struct ptr_data *p1 = *(struct ptr_data *const *)p1_p;
 355   struct ptr_data *p2 = *(struct ptr_data *const *)p2_p;
 356   return (((size_t)p1->new_addr > (size_t)p2->new_addr)
 357           - ((size_t)p1->new_addr < (size_t)p2->new_addr));
 358 }
 359
 360 /* Callbacks for note_ptr_fn.  */
 361
 362 static void
 363 relocate_ptrs (void *ptr_p, void *state_p)
 364 {
 365   void **ptr = (void **)ptr_p;
 366   struct traversal_state *state ATTRIBUTE_UNUSED
 367     = (struct traversal_state *)state_p;
 368   struct ptr_data *result;
 369
 370   if (*ptr == NULL || *ptr == (void *)1)
 371     return;
 372
 373   result = htab_find_with_hash (saving_htab, *ptr, POINTER_HASH (*ptr));
 374   gcc_assert (result);
 375   *ptr = result->new_addr;
 376 }
 377
 378 /* Write out, after relocation, the pointers in TAB.  */
 379 static void
 380 write_pch_globals (const struct ggc_root_tab * const *tab,
 381                    struct traversal_state *state)
 382 {
 383   const struct ggc_root_tab *const *rt;
 384   const struct ggc_root_tab *rti;
 385   size_t i;
 386
 387   for (rt = tab; *rt; rt++)
 388     for (rti = *rt; rti->base != NULL; rti++)
 389       for (i = 0; i < rti->nelt; i++)
 390         {
 391           void *ptr = *(void **)((char *)rti->base + rti->stride * i);
 392           struct ptr_data *new_ptr;
 393           if (ptr == NULL || ptr == (void *)1)
 394             {
 395               if (fwrite (&ptr, sizeof (void *), 1, state->f)
 396                   != 1)
 397                 fatal_error ("can't write PCH file: %m");
 398             }
 399           else
 400             {
 401               new_ptr = htab_find_with_hash (saving_htab, ptr,
 402                                              POINTER_HASH (ptr));
 403               if (fwrite (&new_ptr->new_addr, sizeof (void *), 1, state->f)
 404                   != 1)
 405                 fatal_error ("can't write PCH file: %m");
 406             }
 407         }
 408 }
 409
 410 /* Hold the information we need to mmap the file back in.  */
 411
 412 struct mmap_info
 413 {
 414   size_t offset;
 415   size_t size;
 416   void *preferred_base;
 417 };
 418
 419 /* Write out the state of the compiler to F.  */
 420
 421 void
 422 gt_pch_save (FILE *f)
 423 {
 424   const struct ggc_root_tab *const *rt;
 425   const struct ggc_root_tab *rti;
 426   size_t i;
 427   struct traversal_state state;
 428   char *this_object = NULL;
 429   size_t this_object_size = 0;
 430   struct mmap_info mmi;
 431   const size_t mmap_offset_alignment = host_hooks.gt_pch_alloc_granularity();
 432
 433   gt_pch_save_stringpool ();
 434
 435   saving_htab = htab_create (50000, saving_htab_hash, saving_htab_eq, free);
 436
 437   for (rt = gt_ggc_rtab; *rt; rt++)
 438     for (rti = *rt; rti->base != NULL; rti++)
 439       for (i = 0; i < rti->nelt; i++)
 440         (*rti->pchw)(*(void **)((char *)rti->base + rti->stride * i));
 441
 442   for (rt = gt_pch_cache_rtab; *rt; rt++)
 443     for (rti = *rt; rti->base != NULL; rti++)
 444       for (i = 0; i < rti->nelt; i++)
 445         (*rti->pchw)(*(void **)((char *)rti->base + rti->stride * i));
 446
 447   /* Prepare the objects for writing, determine addresses and such.  */
 448   state.f = f;
 449   state.d = init_ggc_pch();
 450   state.count = 0;
 451   htab_traverse (saving_htab, call_count, &state);
 452
 453   mmi.size = ggc_pch_total_size (state.d);
 454
 455   /* Try to arrange things so that no relocation is necessary, but
 456      don't try very hard.  On most platforms, this will always work,
 457      and on the rest it's a lot of work to do better.
 458      (The extra work goes in HOST_HOOKS_GT_PCH_GET_ADDRESS and
 459      HOST_HOOKS_GT_PCH_USE_ADDRESS.)  */
 460   mmi.preferred_base = host_hooks.gt_pch_get_address (mmi.size, fileno (f));
 461
 462   ggc_pch_this_base (state.d, mmi.preferred_base);
 463
 464   state.ptrs = xmalloc (state.count * sizeof (*state.ptrs));
 465   state.ptrs_i = 0;
 466   htab_traverse (saving_htab, call_alloc, &state);
 467   qsort (state.ptrs, state.count, sizeof (*state.ptrs), compare_ptr_data);
 468
 469   /* Write out all the scalar variables.  */
 470   for (rt = gt_pch_scalar_rtab; *rt; rt++)
 471     for (rti = *rt; rti->base != NULL; rti++)
 472       if (fwrite (rti->base, rti->stride, 1, f) != 1)
 473         fatal_error ("can't write PCH file: %m");
 474
 475   /* Write out all the global pointers, after translation.  */
 476   write_pch_globals (gt_ggc_rtab, &state);
 477   write_pch_globals (gt_pch_cache_rtab, &state);
 478
 479   ggc_pch_prepare_write (state.d, state.f);
 480
 481   /* Pad the PCH file so that the mmapped area starts on an allocation
 482      granularity (usually page) boundary.  */
 483   {
 484     long o;
 485     o = ftell (state.f) + sizeof (mmi);
 486     if (o == -1)
 487       fatal_error ("can't get position in PCH file: %m");
 488     mmi.offset = mmap_offset_alignment - o % mmap_offset_alignment;
 489     if (mmi.offset == mmap_offset_alignment)
 490       mmi.offset = 0;
 491     mmi.offset += o;
 492   }
 493   if (fwrite (&mmi, sizeof (mmi), 1, state.f) != 1)
 494     fatal_error ("can't write PCH file: %m");
 495   if (mmi.offset != 0
 496       && fseek (state.f, mmi.offset, SEEK_SET) != 0)
 497     fatal_error ("can't write padding to PCH file: %m");
 498
 499   /* Actually write out the objects.  */
 500   for (i = 0; i < state.count; i++)
 501     {
 502       if (this_object_size < state.ptrs[i]->size)
 503         {
 504           this_object_size = state.ptrs[i]->size;
 505           this_object = xrealloc (this_object, this_object_size);
 506         }
 507       memcpy (this_object, state.ptrs[i]->obj, state.ptrs[i]->size);
 508       if (state.ptrs[i]->reorder_fn != NULL)
 509         state.ptrs[i]->reorder_fn (state.ptrs[i]->obj,
 510                                    state.ptrs[i]->note_ptr_cookie,
 511                                    relocate_ptrs, &state);
 512       state.ptrs[i]->note_ptr_fn (state.ptrs[i]->obj,
 513                                   state.ptrs[i]->note_ptr_cookie,
 514                                   relocate_ptrs, &state);
 515       ggc_pch_write_object (state.d, state.f, state.ptrs[i]->obj,
 516                             state.ptrs[i]->new_addr, state.ptrs[i]->size,
 517                             state.ptrs[i]->note_ptr_fn == gt_pch_p_S);
 518       if (state.ptrs[i]->note_ptr_fn != gt_pch_p_S)
 519         memcpy (state.ptrs[i]->obj, this_object, state.ptrs[i]->size);
 520     }
 521   ggc_pch_finish (state.d, state.f);
 522   gt_pch_fixup_stringpool ();
 523
 524   free (state.ptrs);
 525   htab_delete (saving_htab);
 526 }
 527
 528 /* Read the state of the compiler back in from F.  */
 529
 530 void
 531 gt_pch_restore (FILE *f)
 532 {
 533   const struct ggc_root_tab *const *rt;
 534   const struct ggc_root_tab *rti;
 535   size_t i;
 536   struct mmap_info mmi;
 537   int result;
 538
 539   /* Delete any deletable objects.  This makes ggc_pch_read much
 540      faster, as it can be sure that no GCable objects remain other
 541      than the ones just read in.  */
 542   for (rt = gt_ggc_deletable_rtab; *rt; rt++)
 543     for (rti = *rt; rti->base != NULL; rti++)
 544       memset (rti->base, 0, rti->stride);
 545
 546   /* Read in all the scalar variables.  */
 547   for (rt = gt_pch_scalar_rtab; *rt; rt++)
 548     for (rti = *rt; rti->base != NULL; rti++)
 549       if (fread (rti->base, rti->stride, 1, f) != 1)
 550         fatal_error ("can't read PCH file: %m");
 551
 552   /* Read in all the global pointers, in 6 easy loops.  */
 553   for (rt = gt_ggc_rtab; *rt; rt++)
 554     for (rti = *rt; rti->base != NULL; rti++)
 555       for (i = 0; i < rti->nelt; i++)
 556         if (fread ((char *)rti->base + rti->stride * i,
 557                    sizeof (void *), 1, f) != 1)
 558           fatal_error ("can't read PCH file: %m");
 559
 560   for (rt = gt_pch_cache_rtab; *rt; rt++)
 561     for (rti = *rt; rti->base != NULL; rti++)
 562       for (i = 0; i < rti->nelt; i++)
 563         if (fread ((char *)rti->base + rti->stride * i,
 564                    sizeof (void *), 1, f) != 1)
 565           fatal_error ("can't read PCH file: %m");
 566
 567   if (fread (&mmi, sizeof (mmi), 1, f) != 1)
 568     fatal_error ("can't read PCH file: %m");
 569
 570   result = host_hooks.gt_pch_use_address (mmi.preferred_base, mmi.size,
 571                                           fileno (f), mmi.offset);
 572   if (result < 0)
 573     fatal_error ("had to relocate PCH");
 574   if (result == 0)
 575     {
 576       if (fseek (f, mmi.offset, SEEK_SET) != 0
 577           || fread (mmi.preferred_base, mmi.size, 1, f) != 1)
 578         fatal_error ("can't read PCH file: %m");
 579     }
 580   else if (fseek (f, mmi.offset + mmi.size, SEEK_SET) != 0)
 581     fatal_error ("can't read PCH file: %m");
 582
 583   ggc_pch_read (f, mmi.preferred_base);
 584
 585   gt_pch_restore_stringpool ();
 586 }
 587
 588 /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS when mmap is not present.
 589    Select no address whatsoever, and let gt_pch_save choose what it will with
 590    malloc, presumably.  */
 591
 592 void *
 593 default_gt_pch_get_address (size_t size ATTRIBUTE_UNUSED,
 594                             int fd ATTRIBUTE_UNUSED)
 595 {
 596   return NULL;
 597 }
 598
 599 /* Default version of HOST_HOOKS_GT_PCH_USE_ADDRESS when mmap is not present.
 600    Allocate SIZE bytes with malloc.  Return 0 if the address we got is the
 601    same as base, indicating that the memory has been allocated but needs to
 602    be read in from the file.  Return -1 if the address differs, to relocation
 603    of the PCH file would be required.  */
 604
 605 int
 606 default_gt_pch_use_address (void *base, size_t size, int fd ATTRIBUTE_UNUSED,
 607                             size_t offset ATTRIBUTE_UNUSED)
 608 {
 609   void *addr = xmalloc (size);
 610   return (addr == base) - 1;
 611 }
 612
 613 /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS.   Return the
 614    alignment required for allocating virtual memory. Usually this is the
 615    same as pagesize.  */
 616
 617 size_t
 618 default_gt_pch_alloc_granularity (void)
 619 {
 620   return getpagesize();
 621 }
 622
 623 #if HAVE_MMAP_FILE
 624 /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS when mmap is present.
 625    We temporarily allocate SIZE bytes, and let the kernel place the data
 626    wherever it will.  If it worked, that's our spot, if not we're likely
 627    to be in trouble.  */
 628
 629 void *
 630 mmap_gt_pch_get_address (size_t size, int fd)
 631 {
 632   void *ret;
 633
 634   ret = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 635   if (ret == (void *) MAP_FAILED)
 636     ret = NULL;
 637   else
 638     munmap (ret, size);
 639
 640   return ret;
 641 }
 642
 643 /* Default version of HOST_HOOKS_GT_PCH_USE_ADDRESS when mmap is present.
 644    Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at
 645    mapping the data at BASE, -1 if we couldn't.
 646
 647    This version assumes that the kernel honors the START operand of mmap
 648    even without MAP_FIXED if START through START+SIZE are not currently
 649    mapped with something.  */
 650
 651 int
 652 mmap_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
 653 {
 654   void *addr;
 655
 656   /* We're called with size == 0 if we're not planning to load a PCH
 657      file at all.  This allows the hook to free any static space that
 658      we might have allocated at link time.  */
 659   if (size == 0)
 660     return -1;
 661
 662   addr = mmap (base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
 663                fd, offset);
 664
 665   return addr == base ? 1 : -1;
 666 }
 667 #endif /* HAVE_MMAP_FILE */
 668
 669 /* Modify the bound based on rlimits.  */
 670 static double
 671 ggc_rlimit_bound (double limit)
 672 {
 673 #if defined(HAVE_GETRLIMIT)
 674   struct rlimit rlim;
 675 # if defined (RLIMIT_AS)
 676   /* RLIMIT_AS is what POSIX says is the limit on mmap.  Presumably
 677      any OS which has RLIMIT_AS also has a working mmap that GCC will use.  */
 678   if (getrlimit (RLIMIT_AS, &rlim) == 0
 679       && rlim.rlim_cur != (rlim_t) RLIM_INFINITY
 680       && rlim.rlim_cur < limit)
 681     limit = rlim.rlim_cur;
 682 # elif defined (RLIMIT_DATA)
 683   /* ... but some older OSs bound mmap based on RLIMIT_DATA, or we
 684      might be on an OS that has a broken mmap.  (Others don't bound
 685      mmap at all, apparently.)  */
 686   if (getrlimit (RLIMIT_DATA, &rlim) == 0
 687       && rlim.rlim_cur != (rlim_t) RLIM_INFINITY
 688       && rlim.rlim_cur < limit
 689       /* Darwin has this horribly bogus default setting of
 690          RLIMIT_DATA, to 6144Kb.  No-one notices because RLIMIT_DATA
 691          appears to be ignored.  Ignore such silliness.  If a limit
 692          this small was actually effective for mmap, GCC wouldn't even
 693          start up.  */
 694       && rlim.rlim_cur >= 8 * 1024 * 1024)
 695     limit = rlim.rlim_cur;
 696 # endif /* RLIMIT_AS or RLIMIT_DATA */
 697 #endif /* HAVE_GETRLIMIT */
 698
 699   return limit;
 700 }
 701
 702 /* Heuristic to set a default for GGC_MIN_EXPAND.  */
 703 int
 704 ggc_min_expand_heuristic (void)
 705 {
 706   double min_expand = physmem_total();
 707
 708   /* Adjust for rlimits.  */
 709   min_expand = ggc_rlimit_bound (min_expand);
 710
 711   /* The heuristic is a percentage equal to 30% + 70%*(RAM/1GB), yielding
 712      a lower bound of 30% and an upper bound of 100% (when RAM >= 1GB).  */
 713   min_expand /= 1024*1024*1024;
 714   min_expand *= 70;
 715   min_expand = MIN (min_expand, 70);
 716   min_expand += 30;
 717
 718   return min_expand;
 719 }
 720
 721 /* Heuristic to set a default for GGC_MIN_HEAPSIZE.  */
 722 int
 723 ggc_min_heapsize_heuristic (void)
 724 {
 725   double phys_kbytes = physmem_total();
 726   double limit_kbytes = ggc_rlimit_bound (phys_kbytes * 2);
 727
 728   phys_kbytes /= 1024; /* Convert to Kbytes.  */
 729   limit_kbytes /= 1024;
 730
 731   /* The heuristic is RAM/8, with a lower bound of 4M and an upper
 732      bound of 128M (when RAM >= 1GB).  */
 733   phys_kbytes /= 8;
 734
 735 #if defined(HAVE_GETRLIMIT) && defined (RLIMIT_RSS)
 736   /* Try not to overrun the RSS limit while doing garbage collection.
 737      The RSS limit is only advisory, so no margin is subtracted.  */
 738  {
 739    struct rlimit rlim;
 740    if (getrlimit (RLIMIT_RSS, &rlim) == 0
 741        && rlim.rlim_cur != (rlim_t) RLIM_INFINITY)
 742      phys_kbytes = MIN (phys_kbytes, rlim.rlim_cur / 1024);
 743  }
 744 # endif
 745
 746   /* Don't blindly run over our data limit; do GC at least when the
 747      *next* GC would be within 16Mb of the limit.  If GCC does hit the
 748      data limit, compilation will fail, so this tries to be
 749      conservative.  */
 750   limit_kbytes = MAX (0, limit_kbytes - 16 * 1024);
 751   limit_kbytes = (limit_kbytes * 100) / (110 + ggc_min_expand_heuristic());
 752   phys_kbytes = MIN (phys_kbytes, limit_kbytes);
 753
 754   phys_kbytes = MAX (phys_kbytes, 4 * 1024);
 755   phys_kbytes = MIN (phys_kbytes, 128 * 1024);
 756
 757   return phys_kbytes;
 758 }
 759
 760 void
 761 init_ggc_heuristics (void)
 762 {
 763 #if !defined ENABLE_GC_CHECKING && !defined ENABLE_GC_ALWAYS_COLLECT
 764   set_param_value ("ggc-min-expand", ggc_min_expand_heuristic());
 765   set_param_value ("ggc-min-heapsize", ggc_min_heapsize_heuristic());
 766 #endif
 767 }
 768
 769 #ifdef GATHER_STATISTICS
 770
 771 /* Datastructure used to store per-call-site statistics.  */
 772 struct loc_descriptor
 773 {
 774   const char *file;
 775   int line;
 776   const char *function;
 777   int times;
 778   size_t allocated;
 779   size_t overhead;
 780   size_t freed;
 781   size_t collected;
 782 };
 783
 784 /* Hashtable used for statistics.  */
 785 static htab_t loc_hash;
 786
 787 /* Hash table helpers functions.  */
 788 static hashval_t
 789 hash_descriptor (const void *p)
 790 {
 791   const struct loc_descriptor *d = p;
 792
 793   return htab_hash_pointer (d->function) | d->line;
 794 }
 795
 796 static int
 797 eq_descriptor (const void *p1, const void *p2)
 798 {
 799   const struct loc_descriptor *d = p1;
 800   const struct loc_descriptor *d2 = p2;
 801
 802   return (d->file == d2->file && d->line == d2->line
 803           && d->function == d2->function);
 804 }
 805
 806 /* Hashtable converting address of allocated field to loc descriptor.  */
 807 static htab_t ptr_hash;
 808 struct ptr_hash_entry
 809 {
 810   void *ptr;
 811   struct loc_descriptor *loc;
 812   size_t size;
 813 };
 814
 815 /* Hash table helpers functions.  */
 816 static hashval_t
 817 hash_ptr (const void *p)
 818 {
 819   const struct ptr_hash_entry *d = p;
 820
 821   return htab_hash_pointer (d->ptr);
 822 }
 823
 824 static int
 825 eq_ptr (const void *p1, const void *p2)
 826 {
 827   const struct ptr_hash_entry *p = p1;
 828
 829   return (p->ptr == p2);
 830 }
 831
 832 /* Return descriptor for given call site, create new one if needed.  */
 833 static struct loc_descriptor *
 834 loc_descriptor (const char *name, int line, const char *function)
 835 {
 836   struct loc_descriptor loc;
 837   struct loc_descriptor **slot;
 838
 839   loc.file = name;
 840   loc.line = line;
 841   loc.function = function;
 842   if (!loc_hash)
 843     loc_hash = htab_create (10, hash_descriptor, eq_descriptor, NULL);
 844
 845   slot = (struct loc_descriptor **) htab_find_slot (loc_hash, &loc, 1);
 846   if (*slot)
 847     return *slot;
 848   *slot = xcalloc (sizeof (**slot), 1);
 849   (*slot)->file = name;
 850   (*slot)->line = line;
 851   (*slot)->function = function;
 852   return *slot;
 853 }
 854
 855 /* Record ALLOCATED and OVERHEAD bytes to descriptor NAME:LINE (FUNCTION).  */
 856 void
 857 ggc_record_overhead (size_t allocated, size_t overhead, void *ptr,
 858                      const char *name, int line, const char *function)
 859 {
 860   struct loc_descriptor *loc = loc_descriptor (name, line, function);
 861   struct ptr_hash_entry *p = xmalloc (sizeof (struct ptr_hash_entry));
 862   PTR *slot;
 863
 864   p->ptr = ptr;
 865   p->loc = loc;
 866   p->size = allocated + overhead;
 867   if (!ptr_hash)
 868     ptr_hash = htab_create (10, hash_ptr, eq_ptr, NULL);
 869   slot = htab_find_slot_with_hash (ptr_hash, ptr, htab_hash_pointer (ptr), INSERT);
 870   gcc_assert (!*slot);
 871   *slot = p;
 872
 873   loc->times++;
 874   loc->allocated+=allocated;
 875   loc->overhead+=overhead;
 876 }
 877
 878 /* Helper function for prune_overhead_list.  See if SLOT is still marked and
 879    remove it from hashtable if it is not.  */
 880 static int
 881 ggc_prune_ptr (void **slot, void *b ATTRIBUTE_UNUSED)
 882 {
 883   struct ptr_hash_entry *p = *slot;
 884   if (!ggc_marked_p (p->ptr))
 885     {
 886       p->loc->collected += p->size;
 887       htab_clear_slot (ptr_hash, slot);
 888       free (p);
 889     }
 890   return 1;
 891 }
 892
 893 /* After live values has been marked, walk all recorded pointers and see if
 894    they are still live.  */
 895 void
 896 ggc_prune_overhead_list (void)
 897 {
 898   htab_traverse (ptr_hash, ggc_prune_ptr, NULL);
 899 }
 900
 901 /* Notice that the pointer has been freed.  */
 902 void ggc_free_overhead (void *ptr)
 903 {
 904   PTR *slot = htab_find_slot_with_hash (ptr_hash, ptr, htab_hash_pointer (ptr),
 905                                         NO_INSERT);
 906   struct ptr_hash_entry *p = *slot;
 907   p->loc->freed += p->size;
 908   htab_clear_slot (ptr_hash, slot);
 909   free (p);
 910 }
 911
 912 /* Helper for qsort; sort descriptors by amount of memory consumed.  */
 913 static int
 914 cmp_statistic (const void *loc1, const void *loc2)
 915 {
 916   struct loc_descriptor *l1 = *(struct loc_descriptor **) loc1;
 917   struct loc_descriptor *l2 = *(struct loc_descriptor **) loc2;
 918   return ((l1->allocated + l1->overhead - l1->freed) -
 919           (l2->allocated + l2->overhead - l2->freed));
 920 }
 921
 922 /* Collect array of the descriptors from hashtable.  */
 923 struct loc_descriptor **loc_array;
 924 static int
 925 add_statistics (void **slot, void *b)
 926 {
 927   int *n = (int *)b;
 928   loc_array[*n] = (struct loc_descriptor *) *slot;
 929   (*n)++;
 930   return 1;
 931 }
 932
 933 /* Dump per-site memory statistics.  */
 934 #endif
 935 void dump_ggc_loc_statistics (void)
 936 {
 937 #ifdef GATHER_STATISTICS
 938   int nentries = 0;
 939   char s[4096];
 940   size_t collected = 0, freed = 0, allocated = 0, overhead = 0, times = 0;
 941   int i;
 942
 943   ggc_force_collect = true;
 944   ggc_collect ();
 945
 946   loc_array = xcalloc (sizeof (*loc_array), loc_hash->n_elements);
 947   fprintf (stderr, "-------------------------------------------------------\n");
 948   fprintf (stderr, "\n%-48s %10s       %10s       %10s       %10s       %10s\n",
 949            "source location", "Garbage", "Freed", "Leak", "Overhead", "Times");
 950   fprintf (stderr, "-------------------------------------------------------\n");
 951   htab_traverse (loc_hash, add_statistics, &nentries);
 952   qsort (loc_array, nentries, sizeof (*loc_array), cmp_statistic);
 953   for (i = 0; i < nentries; i++)
 954     {
 955       struct loc_descriptor *d = loc_array[i];
 956       allocated += d->allocated;
 957       times += d->times;
 958       freed += d->freed;
 959       collected += d->collected;
 960       overhead += d->overhead;
 961     }
 962   for (i = 0; i < nentries; i++)
 963     {
 964       struct loc_descriptor *d = loc_array[i];
 965       if (d->allocated)
 966         {
 967           const char *s1 = d->file;
 968           const char *s2;
 969           while ((s2 = strstr (s1, "gcc/")))
 970             s1 = s2 + 4;
 971           sprintf (s, "%s:%i (%s)", s1, d->line, d->function);
 972           s[48] = 0;
 973           fprintf (stderr, "%-48s %10li:%4.1f%% %10li:%4.1f%% %10li:%4.1f%% %10li:%4.1f%% %10li\n", s,
 974                    (long)d->collected,
 975                    (d->collected) * 100.0 / collected,
 976                    (long)d->freed,
 977                    (d->freed) * 100.0 / freed,
 978                    (long)(d->allocated + d->overhead - d->freed - d->collected),
 979                    (d->allocated + d->overhead - d->freed - d->collected) * 100.0
 980                    / (allocated + overhead - freed - collected),
 981                    (long)d->overhead,
 982                    d->overhead * 100.0 / overhead,
 983                    (long)d->times);
 984         }
 985     }
 986   fprintf (stderr, "%-48s %10ld       %10ld       %10ld       %10ld       %10ld\n",
 987            "Total", (long)collected, (long)freed,
 988            (long)(allocated + overhead - freed - collected), (long)overhead,
 989            (long)times);
 990   fprintf (stderr, "%-48s %10s       %10s       %10s       %10s       %10s\n",
 991            "source location", "Garbage", "Freed", "Leak", "Overhead", "Times");
 992   fprintf (stderr, "-------------------------------------------------------\n");
 993 #endif
 994 }