gcc/ggc-common.c

   1 /* Simple garbage collection for the GNU compiler.
   2    Copyright (C) 1999, 2000 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 GNU CC is distributed in the hope that it will be useful, but WITHOUT
  12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to the Free
  18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 /* Generic garbage collection (GC) functions and data, not specific to
  22    any particular GC implementation.  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "rtl.h"
  27 #include "tree.h"
  28 #include "tm_p.h"
  29 #include "hash.h"
  30 #include "varray.h"
  31 #include "ggc.h"
  32
  33 /* Statistics about the allocation.  */
  34 static ggc_statistics *ggc_stats;
  35
  36 /* Trees that have been marked, but whose children still need marking.  */
  37 varray_type ggc_pending_trees;
  38
  39 static void ggc_mark_rtx_ptr PARAMS ((void *));
  40 static void ggc_mark_tree_ptr PARAMS ((void *));
  41 static void ggc_mark_rtx_varray_ptr PARAMS ((void *));
  42 static void ggc_mark_tree_varray_ptr PARAMS ((void *));
  43 static void ggc_mark_tree_hash_table_ptr PARAMS ((void *));
  44 static void ggc_mark_string_ptr PARAMS ((void *));
  45 static void ggc_mark_trees PARAMS ((void));
  46 static boolean ggc_mark_tree_hash_table_entry PARAMS ((struct hash_entry *,
  47                                                        hash_table_key));
  48
  49 /* Maintain global roots that are preserved during GC.  */
  50
  51 /* Global roots that are preserved during calls to gc.  */
  52
  53 struct ggc_root
  54 {
  55   struct ggc_root *next;
  56   void *base;
  57   int nelt;
  58   int size;
  59   void (*cb) PARAMS ((void *));
  60 };
  61
  62 static struct ggc_root *roots;
  63
  64 /* Add BASE as a new garbage collection root.  It is an array of
  65    length NELT with each element SIZE bytes long.  CB is a
  66    function that will be called with a pointer to each element
  67    of the array; it is the intention that CB call the appropriate
  68    routine to mark gc-able memory for that element.  */
  69
  70 void
  71 ggc_add_root (base, nelt, size, cb)
  72      void *base;
  73      int nelt, size;
  74      void (*cb) PARAMS ((void *));
  75 {
  76   struct ggc_root *x = (struct ggc_root *) xmalloc (sizeof (*x));
  77
  78   x->next = roots;
  79   x->base = base;
  80   x->nelt = nelt;
  81   x->size = size;
  82   x->cb = cb;
  83
  84   roots = x;
  85 }
  86
  87 /* Register an array of rtx as a GC root.  */
  88
  89 void
  90 ggc_add_rtx_root (base, nelt)
  91      rtx *base;
  92      int nelt;
  93 {
  94   ggc_add_root (base, nelt, sizeof (rtx), ggc_mark_rtx_ptr);
  95 }
  96
  97 /* Register an array of trees as a GC root.  */
  98
  99 void
 100 ggc_add_tree_root (base, nelt)
 101      tree *base;
 102      int nelt;
 103 {
 104   ggc_add_root (base, nelt, sizeof (tree), ggc_mark_tree_ptr);
 105 }
 106
 107 /* Register a varray of rtxs as a GC root.  */
 108
 109 void
 110 ggc_add_rtx_varray_root (base, nelt)
 111      varray_type *base;
 112      int nelt;
 113 {
 114   ggc_add_root (base, nelt, sizeof (varray_type),
 115                 ggc_mark_rtx_varray_ptr);
 116 }
 117
 118 /* Register a varray of trees as a GC root.  */
 119
 120 void
 121 ggc_add_tree_varray_root (base, nelt)
 122      varray_type *base;
 123      int nelt;
 124 {
 125   ggc_add_root (base, nelt, sizeof (varray_type),
 126                 ggc_mark_tree_varray_ptr);
 127 }
 128
 129 /* Register a hash table of trees as a GC root.  */
 130
 131 void
 132 ggc_add_tree_hash_table_root (base, nelt)
 133      struct hash_table **base;
 134      int nelt;
 135 {
 136   ggc_add_root (base, nelt, sizeof (struct hash_table *),
 137                 ggc_mark_tree_hash_table_ptr);
 138 }
 139
 140 /* Register an array of strings as a GC root.  */
 141
 142 void
 143 ggc_add_string_root (base, nelt)
 144      char **base;
 145      int nelt;
 146 {
 147   ggc_add_root (base, nelt, sizeof (char *), ggc_mark_string_ptr);
 148 }
 149
 150 /* Remove the previously registered GC root at BASE.  */
 151
 152 void
 153 ggc_del_root (base)
 154      void *base;
 155 {
 156   struct ggc_root *x, **p;
 157
 158   p = &roots, x = roots;
 159   while (x)
 160     {
 161       if (x->base == base)
 162         {
 163           *p = x->next;
 164           free (x);
 165           return;
 166         }
 167       p = &x->next;
 168       x = x->next;
 169     }
 170
 171   abort();
 172 }
 173
 174 /* Iterate through all registered roots and mark each element.  */
 175
 176 void
 177 ggc_mark_roots ()
 178 {
 179   struct ggc_root* x;
 180
 181   VARRAY_TREE_INIT (ggc_pending_trees, 4096, "ggc_pending_trees");
 182
 183   for (x = roots; x != NULL; x = x->next)
 184     {
 185       char *elt = x->base;
 186       int s = x->size, n = x->nelt;
 187       void (*cb) PARAMS ((void *)) = x->cb;
 188       int i;
 189
 190       for (i = 0; i < n; ++i, elt += s)
 191         (*cb)(elt);
 192     }
 193
 194   /* Mark all the queued up trees, and their children.  */
 195   ggc_mark_trees ();
 196   VARRAY_FREE (ggc_pending_trees);
 197 }
 198
 199 /* R had not been previously marked, but has now been marked via
 200    ggc_set_mark.  Now recurse and process the children.  */
 201
 202 void
 203 ggc_mark_rtx_children (r)
 204      rtx r;
 205 {
 206   const char *fmt;
 207   int i;
 208   rtx next_rtx;
 209
 210   do
 211     {
 212       enum rtx_code code = GET_CODE (r);
 213       /* This gets set to a child rtx to eliminate tail recursion.  */
 214       next_rtx = NULL;
 215
 216       /* Collect statistics, if appropriate.  */
 217       if (ggc_stats)
 218         {
 219           ++ggc_stats->num_rtxs[(int) code];
 220           ggc_stats->size_rtxs[(int) code] += ggc_get_size (r);
 221         }
 222
 223       /* ??? If (some of) these are really pass-dependant info, do we
 224          have any right poking our noses in?  */
 225       switch (code)
 226         {
 227         case JUMP_INSN:
 228           ggc_mark_rtx (JUMP_LABEL (r));
 229           break;
 230         case CODE_LABEL:
 231           ggc_mark_rtx (LABEL_REFS (r));
 232           ggc_mark_string (LABEL_ALTERNATE_NAME (r));
 233           break;
 234         case LABEL_REF:
 235           ggc_mark_rtx (LABEL_NEXTREF (r));
 236           ggc_mark_rtx (CONTAINING_INSN (r));
 237           break;
 238         case ADDRESSOF:
 239           ggc_mark_tree (ADDRESSOF_DECL (r));
 240           break;
 241         case CONST_DOUBLE:
 242           ggc_mark_rtx (CONST_DOUBLE_CHAIN (r));
 243           break;
 244         case NOTE:
 245           switch (NOTE_LINE_NUMBER (r))
 246             {
 247             case NOTE_INSN_RANGE_BEG:
 248             case NOTE_INSN_RANGE_END:
 249             case NOTE_INSN_LIVE:
 250             case NOTE_INSN_EXPECTED_VALUE:
 251               ggc_mark_rtx (NOTE_RANGE_INFO (r));
 252               break;
 253
 254             case NOTE_INSN_BLOCK_BEG:
 255             case NOTE_INSN_BLOCK_END:
 256               ggc_mark_tree (NOTE_BLOCK (r));
 257               break;
 258
 259             default:
 260               if (NOTE_LINE_NUMBER (r) >= 0)
 261                 {
 262             case NOTE_INSN_DELETED_LABEL:
 263                   ggc_mark_string (NOTE_SOURCE_FILE (r));
 264                 }
 265               break;
 266             }
 267           break;
 268
 269         default:
 270           break;
 271         }
 272
 273       for (fmt = GET_RTX_FORMAT (GET_CODE (r)), i = 0; *fmt ; ++fmt, ++i)
 274         {
 275           rtx exp;
 276           switch (*fmt)
 277             {
 278             case 'e': case 'u':
 279               exp = XEXP (r, i);
 280               if (ggc_test_and_set_mark (exp))
 281                 {
 282                   if (next_rtx == NULL)
 283                     next_rtx = exp;
 284                   else
 285                     ggc_mark_rtx_children (exp);
 286                 }
 287               break;
 288             case 'V': case 'E':
 289               ggc_mark_rtvec (XVEC (r, i));
 290               break;
 291             case 'S': case 's':
 292               ggc_mark_if_gcable (XSTR (r, i));
 293               break;
 294             }
 295         }
 296     }
 297   while ((r = next_rtx) != NULL);
 298 }
 299
 300 /* V had not been previously marked, but has now been marked via
 301    ggc_set_mark.  Now recurse and process the children.  */
 302
 303 void
 304 ggc_mark_rtvec_children (v)
 305      rtvec v;
 306 {
 307   int i;
 308
 309   i = GET_NUM_ELEM (v);
 310   while (--i >= 0)
 311     ggc_mark_rtx (RTVEC_ELT (v, i));
 312 }
 313
 314 /* Recursively set marks on all of the children of the
 315    GCC_PENDING_TREES.  */
 316
 317 static void
 318 ggc_mark_trees ()
 319 {
 320   while (ggc_pending_trees->elements_used)
 321     {
 322       tree t;
 323       enum tree_code code;
 324
 325       t = VARRAY_TOP_TREE (ggc_pending_trees);
 326       VARRAY_POP (ggc_pending_trees);
 327       code = TREE_CODE (t);
 328
 329       /* Collect statistics, if appropriate.  */
 330       if (ggc_stats)
 331         {
 332           ++ggc_stats->num_trees[(int) code];
 333           ggc_stats->size_trees[(int) code] += ggc_get_size (t);
 334         }
 335
 336       /* Bits from common.  */
 337       ggc_mark_tree (TREE_TYPE (t));
 338       ggc_mark_tree (TREE_CHAIN (t));
 339
 340       /* Some nodes require special handling.  */
 341       switch (code)
 342         {
 343         case TREE_LIST:
 344           ggc_mark_tree (TREE_PURPOSE (t));
 345           ggc_mark_tree (TREE_VALUE (t));
 346           continue;
 347
 348         case TREE_VEC:
 349           {
 350             int i = TREE_VEC_LENGTH (t);
 351
 352             while (--i >= 0)
 353               ggc_mark_tree (TREE_VEC_ELT (t, i));
 354             continue;
 355           }
 356
 357         case COMPLEX_CST:
 358           ggc_mark_tree (TREE_REALPART (t));
 359           ggc_mark_tree (TREE_IMAGPART (t));
 360           break;
 361
 362         case STRING_CST:
 363           ggc_mark_string (TREE_STRING_POINTER (t));
 364           break;
 365
 366         case PARM_DECL:
 367           ggc_mark_rtx (DECL_INCOMING_RTL (t));
 368           break;
 369
 370         case FIELD_DECL:
 371           ggc_mark_tree (DECL_FIELD_BIT_OFFSET (t));
 372           break;
 373
 374         case IDENTIFIER_NODE:
 375           ggc_mark_string (IDENTIFIER_POINTER (t));
 376           lang_mark_tree (t);
 377           continue;
 378
 379         default:
 380           break;
 381         }
 382
 383       /* But in general we can handle them by class.  */
 384       switch (TREE_CODE_CLASS (code))
 385         {
 386         case 'd': /* A decl node.  */
 387           ggc_mark_string (DECL_SOURCE_FILE (t));
 388           ggc_mark_tree (DECL_SIZE (t));
 389           ggc_mark_tree (DECL_SIZE_UNIT (t));
 390           ggc_mark_tree (DECL_NAME (t));
 391           ggc_mark_tree (DECL_CONTEXT (t));
 392           ggc_mark_tree (DECL_ARGUMENTS (t));
 393           ggc_mark_tree (DECL_RESULT_FLD (t));
 394           ggc_mark_tree (DECL_INITIAL (t));
 395           ggc_mark_tree (DECL_ABSTRACT_ORIGIN (t));
 396           ggc_mark_tree (DECL_ASSEMBLER_NAME (t));
 397           ggc_mark_tree (DECL_SECTION_NAME (t));
 398           ggc_mark_tree (DECL_MACHINE_ATTRIBUTES (t));
 399           ggc_mark_rtx (DECL_RTL (t));
 400           ggc_mark_rtx (DECL_LIVE_RANGE_RTL (t));
 401           ggc_mark_tree (DECL_VINDEX (t));
 402           lang_mark_tree (t);
 403           break;
 404
 405         case 't': /* A type node.  */
 406           ggc_mark_tree (TYPE_SIZE (t));
 407           ggc_mark_tree (TYPE_SIZE_UNIT (t));
 408           ggc_mark_tree (TYPE_ATTRIBUTES (t));
 409           ggc_mark_tree (TYPE_VALUES (t));
 410           ggc_mark_tree (TYPE_POINTER_TO (t));
 411           ggc_mark_tree (TYPE_REFERENCE_TO (t));
 412           ggc_mark_tree (TYPE_NAME (t));
 413           ggc_mark_tree (TYPE_MIN_VALUE (t));
 414           ggc_mark_tree (TYPE_MAX_VALUE (t));
 415           ggc_mark_tree (TYPE_NEXT_VARIANT (t));
 416           ggc_mark_tree (TYPE_MAIN_VARIANT (t));
 417           ggc_mark_tree (TYPE_BINFO (t));
 418           ggc_mark_tree (TYPE_NONCOPIED_PARTS (t));
 419           ggc_mark_tree (TYPE_CONTEXT (t));
 420           lang_mark_tree (t);
 421           break;
 422
 423         case 'b': /* A lexical block.  */
 424           ggc_mark_tree (BLOCK_VARS (t));
 425           ggc_mark_tree (BLOCK_SUBBLOCKS (t));
 426           ggc_mark_tree (BLOCK_SUPERCONTEXT (t));
 427           ggc_mark_tree (BLOCK_ABSTRACT_ORIGIN (t));
 428           break;
 429
 430         case 'c': /* A constant.  */
 431           ggc_mark_rtx (TREE_CST_RTL (t));
 432           break;
 433
 434         case 'r': case '<': case '1':
 435         case '2': case 'e': case 's': /* Expressions.  */
 436           {
 437             int i = TREE_CODE_LENGTH (TREE_CODE (t));
 438             int first_rtl = first_rtl_op (TREE_CODE (t));
 439
 440             while (--i >= 0)
 441               {
 442                 if (i >= first_rtl)
 443                   ggc_mark_rtx ((rtx) TREE_OPERAND (t, i));
 444                 else
 445                   ggc_mark_tree (TREE_OPERAND (t, i));
 446               }
 447             break;
 448           }
 449
 450         case 'x':
 451           lang_mark_tree (t);
 452           break;
 453         }
 454     }
 455 }
 456
 457 /* Mark all the elements of the varray V, which contains rtxs.  */
 458
 459 void
 460 ggc_mark_rtx_varray (v)
 461      varray_type v;
 462 {
 463   int i;
 464
 465   if (v)
 466     for (i = v->num_elements - 1; i >= 0; --i)
 467       ggc_mark_rtx (VARRAY_RTX (v, i));
 468 }
 469
 470 /* Mark all the elements of the varray V, which contains trees.  */
 471
 472 void
 473 ggc_mark_tree_varray (v)
 474      varray_type v;
 475 {
 476   int i;
 477
 478   if (v)
 479     for (i = v->num_elements - 1; i >= 0; --i)
 480       ggc_mark_tree (VARRAY_TREE (v, i));
 481 }
 482
 483 /* Mark the hash table-entry HE.  It's key field is really a tree.  */
 484
 485 static boolean
 486 ggc_mark_tree_hash_table_entry (he, k)
 487      struct hash_entry *he;
 488      hash_table_key k ATTRIBUTE_UNUSED;
 489 {
 490   ggc_mark_tree ((tree) he->key);
 491   return true;
 492 }
 493
 494 /* Mark all the elements of the hash-table H, which contains trees.  */
 495
 496 void
 497 ggc_mark_tree_hash_table (ht)
 498      struct hash_table *ht;
 499 {
 500   hash_traverse (ht, ggc_mark_tree_hash_table_entry, /*info=*/0);
 501 }
 502
 503 /* Type-correct function to pass to ggc_add_root.  It just forwards
 504    *ELT (which is an rtx) to ggc_mark_rtx.  */
 505
 506 static void
 507 ggc_mark_rtx_ptr (elt)
 508      void *elt;
 509 {
 510   ggc_mark_rtx (*(rtx *) elt);
 511 }
 512
 513 /* Type-correct function to pass to ggc_add_root.  It just forwards
 514    *ELT (which is a tree) to ggc_mark_tree.  */
 515
 516 static void
 517 ggc_mark_tree_ptr (elt)
 518      void *elt;
 519 {
 520   ggc_mark_tree (*(tree *) elt);
 521 }
 522
 523 /* Type-correct function to pass to ggc_add_root.  It just forwards
 524    ELT (which is really a varray_type *) to ggc_mark_rtx_varray.  */
 525
 526 static void
 527 ggc_mark_rtx_varray_ptr (elt)
 528      void *elt;
 529 {
 530   ggc_mark_rtx_varray (*(varray_type *) elt);
 531 }
 532
 533 /* Type-correct function to pass to ggc_add_root.  It just forwards
 534    ELT (which is really a varray_type *) to ggc_mark_tree_varray.  */
 535
 536 static void
 537 ggc_mark_tree_varray_ptr (elt)
 538      void *elt;
 539 {
 540   ggc_mark_tree_varray (*(varray_type *) elt);
 541 }
 542
 543 /* Type-correct function to pass to ggc_add_root.  It just forwards
 544    ELT (which is really a struct hash_table **) to
 545    ggc_mark_tree_hash_table.  */
 546
 547 static void
 548 ggc_mark_tree_hash_table_ptr (elt)
 549      void *elt;
 550 {
 551   ggc_mark_tree_hash_table (*(struct hash_table **) elt);
 552 }
 553
 554 /* Type-correct function to pass to ggc_add_root.  It just forwards
 555    ELT (which is really a char **) to ggc_mark_string.  */
 556
 557 static void
 558 ggc_mark_string_ptr (elt)
 559      void *elt;
 560 {
 561   ggc_mark_string (*(char **) elt);
 562 }
 563
 564 /* Allocate a gc-able string.  If CONTENTS is null, then the memory will
 565    be uninitialized.  If LENGTH is -1, then CONTENTS is assumed to be a
 566    null-terminated string and the memory sized accordingly.  Otherwise,
 567    the memory is filled with LENGTH bytes from CONTENTS.  */
 568
 569 char *
 570 ggc_alloc_string (contents, length)
 571      const char *contents;
 572      int length;
 573 {
 574   char *string;
 575
 576   if (length < 0)
 577     {
 578       if (contents == NULL)
 579         return NULL;
 580       length = strlen (contents);
 581     }
 582
 583   string = (char *) ggc_alloc (length + 1);
 584   if (contents != NULL)
 585     memcpy (string, contents, length);
 586   string[length] = 0;
 587
 588   return string;
 589 }
 590
 591 /* Allocate a block of memory, then clear it.  */
 592 void *
 593 ggc_alloc_cleared (size)
 594      size_t size;
 595 {
 596   void *buf = ggc_alloc (size);
 597   memset (buf, 0, size);
 598   return buf;
 599 }
 600
 601 /* Print statistics that are independent of the collector in use.  */
 602
 603 void
 604 ggc_print_statistics (stream, stats)
 605      FILE *stream;
 606      ggc_statistics *stats;
 607 {
 608   int code;
 609
 610   /* Set the pointer so that during collection we will actually gather
 611      the statistics.  */
 612   ggc_stats = stats;
 613
 614   /* Then do one collection to fill in the statistics.  */
 615   ggc_collect ();
 616
 617   /* Total the statistics.  */
 618   for (code = 0; code < MAX_TREE_CODES; ++code)
 619     {
 620       stats->total_num_trees += stats->num_trees[code];
 621       stats->total_size_trees += stats->size_trees[code];
 622     }
 623   for (code = 0; code < NUM_RTX_CODE; ++code)
 624     {
 625       stats->total_num_rtxs += stats->num_rtxs[code];
 626       stats->total_size_rtxs += stats->size_rtxs[code];
 627     }
 628
 629   /* Print the statistics for trees.  */
 630   fprintf (stream, "%-22s%-16s%-16s%-7s\n", "Code",
 631            "Number", "Bytes", "% Total");
 632   for (code = 0; code < MAX_TREE_CODES; ++code)
 633     if (ggc_stats->num_trees[code])
 634       {
 635         fprintf (stream, "%s%*s%-15u %-15lu %7.3f\n",
 636                  tree_code_name[code],
 637                  22 - (int) strlen (tree_code_name[code]), "",
 638                  ggc_stats->num_trees[code],
 639                  (unsigned long) ggc_stats->size_trees[code],
 640                  (100 * ((double) ggc_stats->size_trees[code])
 641                   / ggc_stats->total_size_trees));
 642       }
 643   fprintf (stream,
 644            "%-22s%-15u %-15lu\n", "Total",
 645            ggc_stats->total_num_trees,
 646            (unsigned long) ggc_stats->total_size_trees);
 647
 648   /* Print the statistics for RTL.  */
 649   fprintf (stream, "\n%-22s%-16s%-16s%-7s\n", "Code",
 650            "Number", "Bytes", "% Total");
 651   for (code = 0; code < NUM_RTX_CODE; ++code)
 652     if (ggc_stats->num_rtxs[code])
 653       {
 654         fprintf (stream, "%s%*s%-15u %-15lu %7.3f\n",
 655                  rtx_name[code],
 656                  22 - (int) strlen (rtx_name[code]), "",
 657                  ggc_stats->num_rtxs[code],
 658                  (unsigned long) ggc_stats->size_rtxs[code],
 659                  (100 * ((double) ggc_stats->size_rtxs[code])
 660                   / ggc_stats->total_size_rtxs));
 661       }
 662   fprintf (stream,
 663            "%-22s%-15u %-15lu\n", "Total",
 664            ggc_stats->total_num_rtxs,
 665            (unsigned long) ggc_stats->total_size_rtxs);
 666
 667
 668   /* Don't gather statistics any more.  */
 669   ggc_stats = NULL;
 670 }