src/runtime/purify.c

   1 /*
   2  * C-level stuff to implement Lisp-level PURIFY
   3  */
   4
   5 /*
   6  * This software is part of the SBCL system. See the README file for
   7  * more information.
   8  *
   9  * This software is derived from the CMU CL system, which was
  10  * written at Carnegie Mellon University and released into the
  11  * public domain. The software is in the public domain and is
  12  * provided with absolutely no warranty. See the COPYING and CREDITS
  13  * files for more information.
  14  */
  15
  16 #include <stdio.h>
  17 #include <sys/types.h>
  18 #include <stdlib.h>
  19 #include <strings.h>
  20 #include <errno.h>
  21
  22 #include "sbcl.h"
  23 #include "runtime.h"
  24 #include "os.h"
  25 #include "globals.h"
  26 #include "validate.h"
  27 #include "interrupt.h"
  28 #include "purify.h"
  29 #include "interr.h"
  30 #include "fixnump.h"
  31 #include "gc.h"
  32 #include "gc-internal.h"
  33 #include "thread.h"
  34 #include "genesis/primitive-objects.h"
  35 #include "genesis/static-symbols.h"
  36 #include "genesis/layout.h"
  37 #include "gencgc.h"
  38
  39 /* We don't ever do purification with GENCGC as of 1.0.5.*. There was
  40  * a lot of hairy and fragile ifdeffage in here to support purify on
  41  * x86oids, which has now been removed. So this code can't even be
  42  * compiled with GENCGC any more.  -- JES, 2007-04-30.
  43  */
  44 #ifndef LISP_FEATURE_GENCGC
  45
  46 #define PRINTNOISE
  47
  48 static lispobj *dynamic_space_purify_pointer;
  49
  50 \f
  51 /* These hold the original end of the read_only and static spaces so
  52  * we can tell what are forwarding pointers. */
  53
  54 static lispobj *read_only_end, *static_end;
  55
  56 static lispobj *read_only_free, *static_free;
  57
  58 static lispobj *pscav(lispobj *addr, long nwords, boolean constant);
  59
  60 #define LATERBLOCKSIZE 1020
  61 #define LATERMAXCOUNT 10
  62
  63 static struct
  64 later {
  65     struct later *next;
  66     union {
  67         lispobj *ptr;
  68         long count;
  69     } u[LATERBLOCKSIZE];
  70 } *later_blocks = NULL;
  71 static long later_count = 0;
  72
  73 #if N_WORD_BITS == 32
  74  #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
  75 #elif N_WORD_BITS == 64
  76  #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
  77 #endif
  78
  79 \f
  80 static boolean
  81 forwarding_pointer_p(lispobj obj)
  82 {
  83     lispobj *ptr = native_pointer(obj);
  84
  85     return ((static_end <= ptr && ptr <= static_free) ||
  86             (read_only_end <= ptr && ptr <= read_only_free));
  87 }
  88
  89 static boolean
  90 dynamic_pointer_p(lispobj ptr)
  91 {
  92     return (ptr >= (lispobj)current_dynamic_space
  93             &&
  94             ptr < (lispobj)dynamic_space_purify_pointer);
  95 }
  96
  97 static inline lispobj *
  98 newspace_alloc(long nwords, int constantp)
  99 {
 100     lispobj *ret;
 101     nwords=CEILING(nwords,2);
 102     if(constantp) {
 103         if(read_only_free + nwords >= (lispobj *)READ_ONLY_SPACE_END) {
 104             lose("Ran out of read-only space while purifying!\n");
 105         }
 106         ret=read_only_free;
 107         read_only_free+=nwords;
 108     } else {
 109         if(static_free + nwords >= (lispobj *)STATIC_SPACE_END) {
 110             lose("Ran out of static space while purifying!\n");
 111         }
 112         ret=static_free;
 113         static_free+=nwords;
 114     }
 115     return ret;
 116 }
 117
 118 \f
 119 static void
 120 pscav_later(lispobj *where, long count)
 121 {
 122     struct later *new;
 123
 124     if (count > LATERMAXCOUNT) {
 125         while (count > LATERMAXCOUNT) {
 126             pscav_later(where, LATERMAXCOUNT);
 127             count -= LATERMAXCOUNT;
 128             where += LATERMAXCOUNT;
 129         }
 130     }
 131     else {
 132         if (later_blocks == NULL || later_count == LATERBLOCKSIZE ||
 133             (later_count == LATERBLOCKSIZE-1 && count > 1)) {
 134             new  = (struct later *)malloc(sizeof(struct later));
 135             new->next = later_blocks;
 136             if (later_blocks && later_count < LATERBLOCKSIZE)
 137                 later_blocks->u[later_count].ptr = NULL;
 138             later_blocks = new;
 139             later_count = 0;
 140         }
 141
 142         if (count != 1)
 143             later_blocks->u[later_count++].count = count;
 144         later_blocks->u[later_count++].ptr = where;
 145     }
 146 }
 147
 148 static lispobj
 149 ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 150 {
 151     long nwords;
 152     lispobj result, *new, *old;
 153
 154     nwords = CEILING(1 + HeaderValue(header), 2);
 155
 156     /* Allocate it */
 157     old = (lispobj *)native_pointer(thing);
 158     new = newspace_alloc(nwords,constant);
 159
 160     /* Copy it. */
 161     bcopy(old, new, nwords * sizeof(lispobj));
 162
 163     /* Deposit forwarding pointer. */
 164     result = make_lispobj(new, lowtag_of(thing));
 165     *old = result;
 166
 167     /* Scavenge it. */
 168     pscav(new, nwords, constant);
 169
 170     return result;
 171 }
 172
 173 /* We need to look at the layout to see whether it is a pure structure
 174  * class, and only then can we transport as constant. If it is pure,
 175  * we can ALWAYS transport as a constant. */
 176 static lispobj
 177 ptrans_instance(lispobj thing, lispobj header, boolean /* ignored */ constant)
 178 {
 179     struct layout *layout =
 180       (struct layout *) native_pointer(((struct instance *)native_pointer(thing))->slots[0]);
 181     lispobj pure = layout->pure;
 182
 183     switch (pure) {
 184     case T:
 185         return (ptrans_boxed(thing, header, 1));
 186     case NIL:
 187         return (ptrans_boxed(thing, header, 0));
 188     case 0:
 189         {
 190             /* Substructure: special case for the COMPACT-INFO-ENVs,
 191              * where the instance may have a point to the dynamic
 192              * space placed into it (e.g. the cache-name slot), but
 193              * the lists and arrays at the time of a purify can be
 194              * moved to the RO space. */
 195             long nwords;
 196             lispobj result, *new, *old;
 197
 198             nwords = CEILING(1 + HeaderValue(header), 2);
 199
 200             /* Allocate it */
 201             old = (lispobj *)native_pointer(thing);
 202             new = newspace_alloc(nwords, 0); /*  inconstant */
 203
 204             /* Copy it. */
 205             bcopy(old, new, nwords * sizeof(lispobj));
 206
 207             /* Deposit forwarding pointer. */
 208             result = make_lispobj(new, lowtag_of(thing));
 209             *old = result;
 210
 211             /* Scavenge it. */
 212             pscav(new, nwords, 1);
 213
 214             return result;
 215         }
 216     default:
 217         gc_abort();
 218         return NIL; /* dummy value: return something ... */
 219     }
 220 }
 221
 222 static lispobj
 223 ptrans_fdefn(lispobj thing, lispobj header)
 224 {
 225     long nwords;
 226     lispobj result, *new, *old, oldfn;
 227     struct fdefn *fdefn;
 228
 229     nwords = CEILING(1 + HeaderValue(header), 2);
 230
 231     /* Allocate it */
 232     old = (lispobj *)native_pointer(thing);
 233     new = newspace_alloc(nwords, 0);    /* inconstant */
 234
 235     /* Copy it. */
 236     bcopy(old, new, nwords * sizeof(lispobj));
 237
 238     /* Deposit forwarding pointer. */
 239     result = make_lispobj(new, lowtag_of(thing));
 240     *old = result;
 241
 242     /* Scavenge the function. */
 243     fdefn = (struct fdefn *)new;
 244     oldfn = fdefn->fun;
 245     pscav(&fdefn->fun, 1, 0);
 246     if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
 247         fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 248
 249     return result;
 250 }
 251
 252 static lispobj
 253 ptrans_unboxed(lispobj thing, lispobj header)
 254 {
 255     long nwords;
 256     lispobj result, *new, *old;
 257
 258     nwords = CEILING(1 + HeaderValue(header), 2);
 259
 260     /* Allocate it */
 261     old = (lispobj *)native_pointer(thing);
 262     new = newspace_alloc(nwords,1);     /* always constant */
 263
 264     /* copy it. */
 265     bcopy(old, new, nwords * sizeof(lispobj));
 266
 267     /* Deposit forwarding pointer. */
 268     result = make_lispobj(new , lowtag_of(thing));
 269     *old = result;
 270
 271     return result;
 272 }
 273
 274 static lispobj
 275 ptrans_vector(lispobj thing, long bits, long extra,
 276               boolean boxed, boolean constant)
 277 {
 278     struct vector *vector;
 279     long nwords;
 280     lispobj result, *new;
 281     long length;
 282
 283     vector = (struct vector *)native_pointer(thing);
 284     length = fixnum_value(vector->length)+extra;
 285     // Argh, handle simple-vector-nil separately.
 286     if (bits == 0) {
 287       nwords = 2;
 288     } else {
 289       nwords = CEILING(NWORDS(length, bits) + 2, 2);
 290     }
 291
 292     new=newspace_alloc(nwords, (constant || !boxed));
 293     bcopy(vector, new, nwords * sizeof(lispobj));
 294
 295     result = make_lispobj(new, lowtag_of(thing));
 296     vector->header = result;
 297
 298     if (boxed)
 299         pscav(new, nwords, constant);
 300
 301     return result;
 302 }
 303
 304 static lispobj
 305 ptrans_code(lispobj thing)
 306 {
 307     struct code *code, *new;
 308     long nwords;
 309     lispobj func, result;
 310
 311     code = (struct code *)native_pointer(thing);
 312     nwords = CEILING(HeaderValue(code->header) + fixnum_value(code->code_size),
 313                      2);
 314
 315     new = (struct code *)newspace_alloc(nwords,1); /* constant */
 316
 317     bcopy(code, new, nwords * sizeof(lispobj));
 318
 319     result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 320
 321     /* Stick in a forwarding pointer for the code object. */
 322     *(lispobj *)code = result;
 323
 324     /* Put in forwarding pointers for all the functions. */
 325     for (func = code->entry_points;
 326          func != NIL;
 327          func = ((struct simple_fun *)native_pointer(func))->next) {
 328
 329         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 330
 331         *(lispobj *)native_pointer(func) = result + (func - thing);
 332     }
 333
 334     /* Arrange to scavenge the debug info later. */
 335     pscav_later(&new->debug_info, 1);
 336
 337     /* FIXME: why would this be a fixnum? */
 338     /* "why" is a hard word, but apparently for compiled functions the
 339        trace_table_offset contains the length of the instructions, as
 340        a fixnum.  See CODE-INST-AREA-LENGTH in
 341        src/compiler/target-disassem.lisp.  -- CSR, 2004-01-08 */
 342     if (!(fixnump(new->trace_table_offset)))
 343 #if 0
 344         pscav(&new->trace_table_offset, 1, 0);
 345 #else
 346         new->trace_table_offset = NIL; /* limit lifetime */
 347 #endif
 348
 349     /* Scavenge the constants. */
 350     pscav(new->constants, HeaderValue(new->header)-5, 1);
 351
 352     /* Scavenge all the functions. */
 353     pscav(&new->entry_points, 1, 1);
 354     for (func = new->entry_points;
 355          func != NIL;
 356          func = ((struct simple_fun *)native_pointer(func))->next) {
 357         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 358         gc_assert(!dynamic_pointer_p(func));
 359
 360         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 361         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 4);
 362     }
 363
 364     return result;
 365 }
 366
 367 static lispobj
 368 ptrans_func(lispobj thing, lispobj header)
 369 {
 370     long nwords;
 371     lispobj code, *new, *old, result;
 372     struct simple_fun *function;
 373
 374     /* Thing can either be a function header, a closure function
 375      * header, a closure, or a funcallable-instance. If it's a closure
 376      * or a funcallable-instance, we do the same as ptrans_boxed.
 377      * Otherwise we have to do something strange, 'cause it is buried
 378      * inside a code object. */
 379
 380     if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG) {
 381
 382         /* We can only end up here if the code object has not been
 383          * scavenged, because if it had been scavenged, forwarding pointers
 384          * would have been left behind for all the entry points. */
 385
 386         function = (struct simple_fun *)native_pointer(thing);
 387         code =
 388             make_lispobj
 389             ((native_pointer(thing) -
 390               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 391
 392         /* This will cause the function's header to be replaced with a
 393          * forwarding pointer. */
 394
 395         ptrans_code(code);
 396
 397         /* So we can just return that. */
 398         return function->header;
 399     }
 400     else {
 401         /* It's some kind of closure-like thing. */
 402         nwords = CEILING(1 + HeaderValue(header), 2);
 403         old = (lispobj *)native_pointer(thing);
 404
 405         /* Allocate the new one.  FINs *must* not go in read_only
 406          * space.  Closures can; they never change */
 407
 408         new = newspace_alloc
 409             (nwords,(widetag_of(header)!=FUNCALLABLE_INSTANCE_HEADER_WIDETAG));
 410
 411         /* Copy it. */
 412         bcopy(old, new, nwords * sizeof(lispobj));
 413
 414         /* Deposit forwarding pointer. */
 415         result = make_lispobj(new, lowtag_of(thing));
 416         *old = result;
 417
 418         /* Scavenge it. */
 419         pscav(new, nwords, 0);
 420
 421         return result;
 422     }
 423 }
 424
 425 static lispobj
 426 ptrans_returnpc(lispobj thing, lispobj header)
 427 {
 428     lispobj code, new;
 429
 430     /* Find the corresponding code object. */
 431     code = thing - HeaderValue(header)*sizeof(lispobj);
 432
 433     /* Make sure it's been transported. */
 434     new = *(lispobj *)native_pointer(code);
 435     if (!forwarding_pointer_p(new))
 436         new = ptrans_code(code);
 437
 438     /* Maintain the offset: */
 439     return new + (thing - code);
 440 }
 441
 442 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 443
 444 static lispobj
 445 ptrans_list(lispobj thing, boolean constant)
 446 {
 447     struct cons *old, *new, *orig;
 448     long length;
 449
 450     orig = (struct cons *) newspace_alloc(0,constant);
 451     length = 0;
 452
 453     do {
 454         /* Allocate a new cons cell. */
 455         old = (struct cons *)native_pointer(thing);
 456         new = (struct cons *) newspace_alloc(WORDS_PER_CONS,constant);
 457
 458         /* Copy the cons cell and keep a pointer to the cdr. */
 459         new->car = old->car;
 460         thing = new->cdr = old->cdr;
 461
 462         /* Set up the forwarding pointer. */
 463         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 464
 465         /* And count this cell. */
 466         length++;
 467     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 468              dynamic_pointer_p(thing) &&
 469              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 470
 471     /* Scavenge the list we just copied. */
 472     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 473
 474     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 475 }
 476
 477 static lispobj
 478 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 479 {
 480     switch (widetag_of(header)) {
 481         /* FIXME: this needs a reindent */
 482       case BIGNUM_WIDETAG:
 483       case SINGLE_FLOAT_WIDETAG:
 484       case DOUBLE_FLOAT_WIDETAG:
 485 #ifdef LONG_FLOAT_WIDETAG
 486       case LONG_FLOAT_WIDETAG:
 487 #endif
 488 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 489       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 490 #endif
 491 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 492       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 493 #endif
 494 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 495       case COMPLEX_LONG_FLOAT_WIDETAG:
 496 #endif
 497       case SAP_WIDETAG:
 498           return ptrans_unboxed(thing, header);
 499 #ifdef LUTEX_WIDETAG
 500       case LUTEX_WIDETAG:
 501           gencgc_unregister_lutex((struct lutex *) native_pointer(thing));
 502           return ptrans_unboxed(thing, header);
 503 #endif
 504
 505       case RATIO_WIDETAG:
 506       case COMPLEX_WIDETAG:
 507       case SIMPLE_ARRAY_WIDETAG:
 508       case COMPLEX_BASE_STRING_WIDETAG:
 509 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
 510     case COMPLEX_CHARACTER_STRING_WIDETAG:
 511 #endif
 512       case COMPLEX_BIT_VECTOR_WIDETAG:
 513       case COMPLEX_VECTOR_NIL_WIDETAG:
 514       case COMPLEX_VECTOR_WIDETAG:
 515       case COMPLEX_ARRAY_WIDETAG:
 516         return ptrans_boxed(thing, header, constant);
 517
 518       case VALUE_CELL_HEADER_WIDETAG:
 519       case WEAK_POINTER_WIDETAG:
 520         return ptrans_boxed(thing, header, 0);
 521
 522       case SYMBOL_HEADER_WIDETAG:
 523         return ptrans_boxed(thing, header, 0);
 524
 525       case SIMPLE_ARRAY_NIL_WIDETAG:
 526         return ptrans_vector(thing, 0, 0, 0, constant);
 527
 528       case SIMPLE_BASE_STRING_WIDETAG:
 529         return ptrans_vector(thing, 8, 1, 0, constant);
 530
 531 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
 532     case SIMPLE_CHARACTER_STRING_WIDETAG:
 533         return ptrans_vector(thing, 32, 1, 0, constant);
 534 #endif
 535
 536       case SIMPLE_BIT_VECTOR_WIDETAG:
 537         return ptrans_vector(thing, 1, 0, 0, constant);
 538
 539       case SIMPLE_VECTOR_WIDETAG:
 540         return ptrans_vector(thing, N_WORD_BITS, 0, 1, constant);
 541
 542       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 543         return ptrans_vector(thing, 2, 0, 0, constant);
 544
 545       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 546         return ptrans_vector(thing, 4, 0, 0, constant);
 547
 548       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 549 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 550       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 551       case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 552 #endif
 553         return ptrans_vector(thing, 8, 0, 0, constant);
 554
 555       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 556 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 557       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 558       case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 559 #endif
 560         return ptrans_vector(thing, 16, 0, 0, constant);
 561
 562       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 563 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 564       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 565       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 566 #endif
 567 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 568       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 569       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 570 #endif
 571         return ptrans_vector(thing, 32, 0, 0, constant);
 572
 573 #if N_WORD_BITS == 64
 574 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
 575       case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
 576 #endif
 577 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
 578       case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
 579 #endif
 580 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
 581       case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
 582 #endif
 583 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
 584       case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
 585 #endif
 586 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
 587       case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
 588 #endif
 589         return ptrans_vector(thing, 64, 0, 0, constant);
 590 #endif
 591
 592       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 593         return ptrans_vector(thing, 32, 0, 0, constant);
 594
 595       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 596         return ptrans_vector(thing, 64, 0, 0, constant);
 597
 598 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 599       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 600 #ifdef LISP_FEATURE_SPARC
 601         return ptrans_vector(thing, 128, 0, 0, constant);
 602 #endif
 603 #endif
 604
 605 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 606       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 607         return ptrans_vector(thing, 64, 0, 0, constant);
 608 #endif
 609
 610 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 611       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 612         return ptrans_vector(thing, 128, 0, 0, constant);
 613 #endif
 614
 615 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 616       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 617 #ifdef LISP_FEATURE_SPARC
 618         return ptrans_vector(thing, 256, 0, 0, constant);
 619 #endif
 620 #endif
 621
 622       case CODE_HEADER_WIDETAG:
 623         return ptrans_code(thing);
 624
 625       case RETURN_PC_HEADER_WIDETAG:
 626         return ptrans_returnpc(thing, header);
 627
 628       case FDEFN_WIDETAG:
 629         return ptrans_fdefn(thing, header);
 630
 631       default:
 632         fprintf(stderr, "Invalid widetag: %d\n", widetag_of(header));
 633         /* Should only come across other pointers to the above stuff. */
 634         gc_abort();
 635         return NIL;
 636     }
 637 }
 638
 639 static long
 640 pscav_fdefn(struct fdefn *fdefn)
 641 {
 642     boolean fix_func;
 643
 644     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
 645     pscav(&fdefn->name, 1, 1);
 646     pscav(&fdefn->fun, 1, 0);
 647     if (fix_func)
 648         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
 649     return sizeof(struct fdefn) / sizeof(lispobj);
 650 }
 651
 652 static lispobj *
 653 pscav(lispobj *addr, long nwords, boolean constant)
 654 {
 655     lispobj thing, *thingp, header;
 656     long count = 0; /* (0 = dummy init value to stop GCC warning) */
 657     struct vector *vector;
 658
 659     while (nwords > 0) {
 660         thing = *addr;
 661         if (is_lisp_pointer(thing)) {
 662             /* It's a pointer. Is it something we might have to move? */
 663             if (dynamic_pointer_p(thing)) {
 664                 /* Maybe. Have we already moved it? */
 665                 thingp = (lispobj *)native_pointer(thing);
 666                 header = *thingp;
 667                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
 668                     /* Yep, so just copy the forwarding pointer. */
 669                     thing = header;
 670                 else {
 671                     /* Nope, copy the object. */
 672                     switch (lowtag_of(thing)) {
 673                       case FUN_POINTER_LOWTAG:
 674                         thing = ptrans_func(thing, header);
 675                         break;
 676
 677                       case LIST_POINTER_LOWTAG:
 678                         thing = ptrans_list(thing, constant);
 679                         break;
 680
 681                       case INSTANCE_POINTER_LOWTAG:
 682                         thing = ptrans_instance(thing, header, constant);
 683                         break;
 684
 685                       case OTHER_POINTER_LOWTAG:
 686                         thing = ptrans_otherptr(thing, header, constant);
 687                         break;
 688
 689                       default:
 690                         /* It was a pointer, but not one of them? */
 691                         gc_abort();
 692                     }
 693                 }
 694                 *addr = thing;
 695             }
 696             count = 1;
 697         }
 698 #if N_WORD_BITS == 64
 699         else if (widetag_of(thing) == SINGLE_FLOAT_WIDETAG) {
 700             count = 1;
 701         }
 702 #endif
 703         else if (thing & FIXNUM_TAG_MASK) {
 704             /* It's an other immediate. Maybe the header for an unboxed */
 705             /* object. */
 706             switch (widetag_of(thing)) {
 707               case BIGNUM_WIDETAG:
 708               case SINGLE_FLOAT_WIDETAG:
 709               case DOUBLE_FLOAT_WIDETAG:
 710 #ifdef LONG_FLOAT_WIDETAG
 711               case LONG_FLOAT_WIDETAG:
 712 #endif
 713               case SAP_WIDETAG:
 714                 /* It's an unboxed simple object. */
 715                 count = CEILING(HeaderValue(thing)+1, 2);
 716                 break;
 717
 718               case SIMPLE_VECTOR_WIDETAG:
 719                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
 720                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
 721                         SIMPLE_VECTOR_WIDETAG;
 722                   }
 723                 count = 2;
 724                 break;
 725
 726               case SIMPLE_ARRAY_NIL_WIDETAG:
 727                 count = 2;
 728                 break;
 729
 730               case SIMPLE_BASE_STRING_WIDETAG:
 731                 vector = (struct vector *)addr;
 732                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,8)+2,2);
 733                 break;
 734
 735 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
 736             case SIMPLE_CHARACTER_STRING_WIDETAG:
 737                 vector = (struct vector *)addr;
 738                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,32)+2,2);
 739                 break;
 740 #endif
 741
 742               case SIMPLE_BIT_VECTOR_WIDETAG:
 743                 vector = (struct vector *)addr;
 744                 count = CEILING(NWORDS(fixnum_value(vector->length),1)+2,2);
 745                 break;
 746
 747               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 748                 vector = (struct vector *)addr;
 749                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
 750                 break;
 751
 752               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 753                 vector = (struct vector *)addr;
 754                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
 755                 break;
 756
 757               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 758 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 759               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 760               case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 761 #endif
 762                 vector = (struct vector *)addr;
 763                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
 764                 break;
 765
 766               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 767 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 768               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 769               case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 770 #endif
 771                 vector = (struct vector *)addr;
 772                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
 773                 break;
 774
 775               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 776 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 777               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 778               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 779 #endif
 780 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 781               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 782               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 783 #endif
 784                 vector = (struct vector *)addr;
 785                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
 786                 break;
 787
 788 #if N_WORD_BITS == 64
 789               case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
 790 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
 791               case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
 792               case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
 793 #endif
 794 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
 795               case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
 796               case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
 797 #endif
 798                 vector = (struct vector *)addr;
 799                 count = CEILING(NWORDS(fixnum_value(vector->length),64)+2,2);
 800                 break;
 801 #endif
 802
 803               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 804                 vector = (struct vector *)addr;
 805                 count = CEILING(NWORDS(fixnum_value(vector->length), 32) + 2,
 806                                 2);
 807                 break;
 808
 809               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 810 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 811               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 812 #endif
 813                 vector = (struct vector *)addr;
 814                 count = CEILING(NWORDS(fixnum_value(vector->length), 64) + 2,
 815                                 2);
 816                 break;
 817
 818 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 819               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 820                 vector = (struct vector *)addr;
 821 #ifdef LISP_FEATURE_SPARC
 822                 count = fixnum_value(vector->length)*4+2;
 823 #endif
 824                 break;
 825 #endif
 826
 827 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 828               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 829                 vector = (struct vector *)addr;
 830                 count = CEILING(NWORDS(fixnum_value(vector->length), 128) + 2,
 831                                 2);
 832                 break;
 833 #endif
 834
 835 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 836               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 837                 vector = (struct vector *)addr;
 838 #ifdef LISP_FEATURE_SPARC
 839                 count = fixnum_value(vector->length)*8+2;
 840 #endif
 841                 break;
 842 #endif
 843
 844               case CODE_HEADER_WIDETAG:
 845                 gc_abort(); /* no code headers in static space */
 846                 break;
 847
 848               case SIMPLE_FUN_HEADER_WIDETAG:
 849               case RETURN_PC_HEADER_WIDETAG:
 850                 /* We should never hit any of these, 'cause they occur
 851                  * buried in the middle of code objects. */
 852                 gc_abort();
 853                 break;
 854
 855               case WEAK_POINTER_WIDETAG:
 856                 /* Weak pointers get preserved during purify, 'cause I
 857                  * don't feel like figuring out how to break them. */
 858                 pscav(addr+1, 2, constant);
 859                 count = 4;
 860                 break;
 861
 862               case FDEFN_WIDETAG:
 863                 /* We have to handle fdefn objects specially, so we
 864                  * can fix up the raw function address. */
 865                 count = pscav_fdefn((struct fdefn *)addr);
 866                 break;
 867
 868               case INSTANCE_HEADER_WIDETAG:
 869                 {
 870                     struct instance *instance = (struct instance *) addr;
 871                     struct layout *layout
 872                         = (struct layout *) native_pointer(instance->slots[0]);
 873                     long nuntagged = fixnum_value(layout->n_untagged_slots);
 874                     long nslots = HeaderValue(*addr);
 875                     pscav(addr + 1, nslots - nuntagged, constant);
 876                     count = CEILING(1 + nslots, 2);
 877                 }
 878                 break;
 879
 880               default:
 881                 count = 1;
 882                 break;
 883             }
 884         }
 885         else {
 886             /* It's a fixnum. */
 887             count = 1;
 888         }
 889
 890         addr += count;
 891         nwords -= count;
 892     }
 893
 894     return addr;
 895 }
 896
 897 int
 898 purify(lispobj static_roots, lispobj read_only_roots)
 899 {
 900     lispobj *clean;
 901     long count, i;
 902     struct later *laters, *next;
 903     struct thread *thread;
 904
 905     if(all_threads->next) {
 906         /* FIXME: there should be _some_ sensible error reporting
 907          * convention.  See following comment too */
 908         fprintf(stderr,"Can't purify when more than one thread exists\n");
 909         fflush(stderr);
 910         return 0;
 911     }
 912
 913 #ifdef PRINTNOISE
 914     printf("[doing purification:");
 915     fflush(stdout);
 916 #endif
 917
 918     for_each_thread(thread)
 919         if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)) != 0) {
 920         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
 921          * its error simply by a. printing a string b. to stdout instead
 922          * of stderr. */
 923         printf(" Ack! Can't purify interrupt contexts. ");
 924         fflush(stdout);
 925         return 0;
 926     }
 927
 928     dynamic_space_purify_pointer = dynamic_space_free_pointer;
 929
 930     read_only_end = read_only_free =
 931         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
 932     static_end = static_free =
 933         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
 934
 935 #ifdef PRINTNOISE
 936     printf(" roots");
 937     fflush(stdout);
 938 #endif
 939
 940     pscav(&static_roots, 1, 0);
 941     pscav(&read_only_roots, 1, 1);
 942
 943 #ifdef PRINTNOISE
 944     printf(" handlers");
 945     fflush(stdout);
 946 #endif
 947     pscav((lispobj *) interrupt_handlers,
 948           sizeof(interrupt_handlers) / sizeof(lispobj),
 949           0);
 950
 951 #ifdef PRINTNOISE
 952     printf(" stack");
 953     fflush(stdout);
 954 #endif
 955     pscav((lispobj *)all_threads->control_stack_start,
 956           current_control_stack_pointer -
 957           all_threads->control_stack_start,
 958           0);
 959
 960 #ifdef PRINTNOISE
 961     printf(" bindings");
 962     fflush(stdout);
 963 #endif
 964
 965     pscav( (lispobj *)all_threads->binding_stack_start,
 966           (lispobj *)current_binding_stack_pointer -
 967            all_threads->binding_stack_start,
 968           0);
 969
 970     /* The original CMU CL code had scavenge-read-only-space code
 971      * controlled by the Lisp-level variable
 972      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
 973      * wasn't documented under what circumstances it was useful or
 974      * safe to turn it on, so it's been turned off in SBCL. If you
 975      * want/need this functionality, and can test and document it,
 976      * please submit a patch. */
 977 #if 0
 978     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
 979         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
 980       unsigned  read_only_space_size =
 981           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
 982           (lispobj *)READ_ONLY_SPACE_START;
 983       fprintf(stderr,
 984               "scavenging read only space: %d bytes\n",
 985               read_only_space_size * sizeof(lispobj));
 986       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
 987     }
 988 #endif
 989
 990 #ifdef PRINTNOISE
 991     printf(" static");
 992     fflush(stdout);
 993 #endif
 994     clean = (lispobj *)STATIC_SPACE_START;
 995     do {
 996         while (clean != static_free)
 997             clean = pscav(clean, static_free - clean, 0);
 998         laters = later_blocks;
 999         count = later_count;
1000         later_blocks = NULL;
1001         later_count = 0;
1002         while (laters != NULL) {
1003             for (i = 0; i < count; i++) {
1004                 if (laters->u[i].count == 0) {
1005                     ;
1006                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1007                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1008                     i++;
1009                 } else {
1010                     pscav(laters->u[i].ptr, 1, 1);
1011                 }
1012             }
1013             next = laters->next;
1014             free(laters);
1015             laters = next;
1016             count = LATERBLOCKSIZE;
1017         }
1018     } while (clean != static_free || later_blocks != NULL);
1019
1020 #ifdef PRINTNOISE
1021     printf(" cleanup");
1022     fflush(stdout);
1023 #endif
1024
1025     os_zero((os_vm_address_t) current_dynamic_space,
1026             (os_vm_size_t) dynamic_space_size);
1027
1028     /* Zero the stack. */
1029     os_zero((os_vm_address_t) current_control_stack_pointer,
1030             (os_vm_size_t)
1031             ((all_threads->control_stack_end -
1032               current_control_stack_pointer) * sizeof(lispobj)));
1033
1034     /* It helps to update the heap free pointers so that free_heap can
1035      * verify after it's done. */
1036     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free,0);
1037     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free,0);
1038
1039     dynamic_space_free_pointer = current_dynamic_space;
1040     set_auto_gc_trigger(bytes_consed_between_gcs);
1041
1042     /* Blast away instruction cache */
1043     os_flush_icache((os_vm_address_t)READ_ONLY_SPACE_START, READ_ONLY_SPACE_SIZE);
1044     os_flush_icache((os_vm_address_t)STATIC_SPACE_START, STATIC_SPACE_SIZE);
1045
1046 #ifdef PRINTNOISE
1047     printf(" done]\n");
1048     fflush(stdout);
1049 #endif
1050     return 0;
1051 }
1052 #else /* LISP_FEATURE_GENCGC */
1053 int
1054 purify(lispobj static_roots, lispobj read_only_roots)
1055 {
1056     lose("purify called for GENCGC. This should not happen.");
1057 }
1058 #endif /* LISP_FEATURE_GENCGC */