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
  21 #include "runtime.h"
  22 #include "os.h"
  23 #include "sbcl.h"
  24 #include "globals.h"
  25 #include "validate.h"
  26 #include "interrupt.h"
  27 #include "purify.h"
  28 #include "interr.h"
  29 #include "gc.h"
  30 #include "gc-internal.h"
  31 #include "genesis/primitive-objects.h"
  32 #include "genesis/static-symbols.h"
  33
  34 #define PRINTNOISE
  35
  36 #if defined(__i386__)
  37 /* again, what's so special about the x86 that this is differently
  38  * visible there than on other platforms? -dan 20010125
  39  */
  40 static lispobj *dynamic_space_free_pointer;
  41 #endif
  42
  43 #define gc_abort() \
  44   lose("GC invariant lost, file \"%s\", line %d", __FILE__, __LINE__)
  45
  46 #if 1
  47 #define gc_assert(ex) do { \
  48         if (!(ex)) gc_abort(); \
  49 } while (0)
  50 #else
  51 #define gc_assert(ex)
  52 #endif
  53
  54 \f
  55 /* These hold the original end of the read_only and static spaces so
  56  * we can tell what are forwarding pointers. */
  57
  58 static lispobj *read_only_end, *static_end;
  59
  60 static lispobj *read_only_free, *static_free;
  61
  62 static lispobj *pscav(lispobj *addr, int nwords, boolean constant);
  63
  64 #define LATERBLOCKSIZE 1020
  65 #define LATERMAXCOUNT 10
  66
  67 static struct
  68 later {
  69     struct later *next;
  70     union {
  71         lispobj *ptr;
  72         int count;
  73     } u[LATERBLOCKSIZE];
  74 } *later_blocks = NULL;
  75 static int later_count = 0;
  76
  77 #define CEILING(x,y) (((x) + ((y) - 1)) & (~((y) - 1)))
  78 #define NWORDS(x,y) (CEILING((x),(y)) / (y))
  79
  80 /* FIXME: Shouldn't this be defined in sbcl.h?  See also notes in
  81  * cheneygc.c */
  82
  83 #ifdef sparc
  84 #define FUN_RAW_ADDR_OFFSET 0
  85 #else
  86 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
  87 #endif
  88 \f
  89 static boolean
  90 forwarding_pointer_p(lispobj obj)
  91 {
  92     lispobj *ptr = native_pointer(obj);
  93
  94     return ((static_end <= ptr && ptr <= static_free) ||
  95             (read_only_end <= ptr && ptr <= read_only_free));
  96 }
  97
  98 static boolean
  99 dynamic_pointer_p(lispobj ptr)
 100 {
 101 #ifndef __i386__
 102     return (ptr >= (lispobj)current_dynamic_space
 103             &&
 104             ptr < (lispobj)dynamic_space_free_pointer);
 105 #else
 106     /* Be more conservative, and remember, this is a maybe. */
 107     return (ptr >= (lispobj)DYNAMIC_SPACE_START
 108             &&
 109             ptr < (lispobj)dynamic_space_free_pointer);
 110 #endif
 111 }
 112
 113 \f
 114 #ifdef __i386__
 115
 116 #ifdef LISP_FEATURE_GENCGC
 117 /*
 118  * enhanced x86/GENCGC stack scavenging by Douglas Crosher
 119  *
 120  * Scavenging the stack on the i386 is problematic due to conservative
 121  * roots and raw return addresses. Here it is handled in two passes:
 122  * the first pass runs before any objects are moved and tries to
 123  * identify valid pointers and return address on the stack, the second
 124  * pass scavenges these.
 125  */
 126
 127 static unsigned pointer_filter_verbose = 0;
 128
 129 /* FIXME: This is substantially the same code as in gencgc.c. (There
 130  * are some differences, at least (1) the gencgc.c code needs to worry
 131  * about return addresses on the stack pinning code objects, (2) the
 132  * gencgc.c code needs to worry about the GC maybe happening in an
 133  * interrupt service routine when the main thread of control was
 134  * interrupted just as it had allocated memory and before it
 135  * initialized it, while PURIFY needn't worry about that, and (3) the
 136  * gencgc.c code has mutated more under maintenance since the fork
 137  * from CMU CL than the code here has.) The two versions should be
 138  * made to explicitly share common code, instead of just two different
 139  * cut-and-pasted versions. */
 140 static int
 141 valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
 142 {
 143     /* If it's not a return address then it needs to be a valid Lisp
 144      * pointer. */
 145     if (!is_lisp_pointer((lispobj)pointer))
 146         return 0;
 147
 148     /* Check that the object pointed to is consistent with the pointer
 149      * low tag. */
 150     switch (lowtag_of((lispobj)pointer)) {
 151     case FUN_POINTER_LOWTAG:
 152         /* Start_addr should be the enclosing code object, or a closure
 153          * header. */
 154         switch (widetag_of(*start_addr)) {
 155         case CODE_HEADER_WIDETAG:
 156             /* This case is probably caught above. */
 157             break;
 158         case CLOSURE_HEADER_WIDETAG:
 159         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 160             if ((int)pointer != ((int)start_addr+FUN_POINTER_LOWTAG)) {
 161                 if (pointer_filter_verbose) {
 162                     fprintf(stderr,"*Wf2: %x %x %x\n", (unsigned int) pointer,
 163                             (unsigned int) start_addr, *start_addr);
 164                 }
 165                 return 0;
 166             }
 167             break;
 168         default:
 169             if (pointer_filter_verbose) {
 170                 fprintf(stderr,"*Wf3: %x %x %x\n", (unsigned int) pointer,
 171                         (unsigned int) start_addr, *start_addr);
 172             }
 173             return 0;
 174         }
 175         break;
 176     case LIST_POINTER_LOWTAG:
 177         if ((int)pointer != ((int)start_addr+LIST_POINTER_LOWTAG)) {
 178             if (pointer_filter_verbose)
 179                 fprintf(stderr,"*Wl1: %x %x %x\n", (unsigned int) pointer,
 180                         (unsigned int) start_addr, *start_addr);
 181             return 0;
 182         }
 183         /* Is it plausible cons? */
 184         if ((is_lisp_pointer(start_addr[0])
 185             || ((start_addr[0] & 3) == 0) /* fixnum */
 186             || (widetag_of(start_addr[0]) == BASE_CHAR_WIDETAG)
 187             || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
 188            && (is_lisp_pointer(start_addr[1])
 189                || ((start_addr[1] & 3) == 0) /* fixnum */
 190                || (widetag_of(start_addr[1]) == BASE_CHAR_WIDETAG)
 191                || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
 192             break;
 193         } else {
 194             if (pointer_filter_verbose) {
 195                 fprintf(stderr,"*Wl2: %x %x %x\n", (unsigned int) pointer,
 196                         (unsigned int) start_addr, *start_addr);
 197             }
 198             return 0;
 199         }
 200     case INSTANCE_POINTER_LOWTAG:
 201         if ((int)pointer != ((int)start_addr+INSTANCE_POINTER_LOWTAG)) {
 202             if (pointer_filter_verbose) {
 203                 fprintf(stderr,"*Wi1: %x %x %x\n", (unsigned int) pointer,
 204                         (unsigned int) start_addr, *start_addr);
 205             }
 206             return 0;
 207         }
 208         if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
 209             if (pointer_filter_verbose) {
 210                 fprintf(stderr,"*Wi2: %x %x %x\n", (unsigned int) pointer,
 211                         (unsigned int) start_addr, *start_addr);
 212             }
 213             return 0;
 214         }
 215         break;
 216     case OTHER_POINTER_LOWTAG:
 217         if ((int)pointer != ((int)start_addr+OTHER_POINTER_LOWTAG)) {
 218             if (pointer_filter_verbose) {
 219                 fprintf(stderr,"*Wo1: %x %x %x\n", (unsigned int) pointer,
 220                         (unsigned int) start_addr, *start_addr);
 221             }
 222             return 0;
 223         }
 224         /* Is it plausible? Not a cons. XXX should check the headers. */
 225         if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
 226             if (pointer_filter_verbose) {
 227                 fprintf(stderr,"*Wo2: %x %x %x\n", (unsigned int) pointer,
 228                         (unsigned int) start_addr, *start_addr);
 229             }
 230             return 0;
 231         }
 232         switch (widetag_of(start_addr[0])) {
 233         case UNBOUND_MARKER_WIDETAG:
 234         case BASE_CHAR_WIDETAG:
 235             if (pointer_filter_verbose) {
 236                 fprintf(stderr,"*Wo3: %x %x %x\n", (unsigned int) pointer,
 237                         (unsigned int) start_addr, *start_addr);
 238             }
 239             return 0;
 240
 241             /* only pointed to by function pointers? */
 242         case CLOSURE_HEADER_WIDETAG:
 243         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 244             if (pointer_filter_verbose) {
 245                 fprintf(stderr,"*Wo4: %x %x %x\n", (unsigned int) pointer,
 246                         (unsigned int) start_addr, *start_addr);
 247             }
 248             return 0;
 249
 250         case INSTANCE_HEADER_WIDETAG:
 251             if (pointer_filter_verbose) {
 252                 fprintf(stderr,"*Wo5: %x %x %x\n", (unsigned int) pointer,
 253                         (unsigned int) start_addr, *start_addr);
 254             }
 255             return 0;
 256
 257             /* the valid other immediate pointer objects */
 258         case SIMPLE_VECTOR_WIDETAG:
 259         case RATIO_WIDETAG:
 260         case COMPLEX_WIDETAG:
 261 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 262         case COMPLEX_SINGLE_FLOAT_WIDETAG:
 263 #endif
 264 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 265         case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 266 #endif
 267 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 268         case COMPLEX_LONG_FLOAT_WIDETAG:
 269 #endif
 270         case SIMPLE_ARRAY_WIDETAG:
 271         case COMPLEX_STRING_WIDETAG:
 272         case COMPLEX_BIT_VECTOR_WIDETAG:
 273         case COMPLEX_VECTOR_WIDETAG:
 274         case COMPLEX_ARRAY_WIDETAG:
 275         case VALUE_CELL_HEADER_WIDETAG:
 276         case SYMBOL_HEADER_WIDETAG:
 277         case FDEFN_WIDETAG:
 278         case CODE_HEADER_WIDETAG:
 279         case BIGNUM_WIDETAG:
 280         case SINGLE_FLOAT_WIDETAG:
 281         case DOUBLE_FLOAT_WIDETAG:
 282 #ifdef LONG_FLOAT_WIDETAG
 283         case LONG_FLOAT_WIDETAG:
 284 #endif
 285         case SIMPLE_STRING_WIDETAG:
 286         case SIMPLE_BIT_VECTOR_WIDETAG:
 287         case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 288         case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 289         case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 290         case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 291         case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 292 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 293         case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 294 #endif
 295 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 296         case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 297 #endif
 298 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 299         case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 300 #endif
 301 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 302         case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 303 #endif
 304         case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 305         case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 306 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 307         case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 308 #endif
 309 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 310         case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 311 #endif
 312 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 313         case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 314 #endif
 315 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 316         case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 317 #endif
 318         case SAP_WIDETAG:
 319         case WEAK_POINTER_WIDETAG:
 320             break;
 321
 322         default:
 323             if (pointer_filter_verbose) {
 324                 fprintf(stderr,"*Wo6: %x %x %x\n", (unsigned int) pointer,
 325                         (unsigned int) start_addr, *start_addr);
 326             }
 327             return 0;
 328         }
 329         break;
 330     default:
 331         if (pointer_filter_verbose) {
 332             fprintf(stderr,"*W?: %x %x %x\n", (unsigned int) pointer,
 333                     (unsigned int) start_addr, *start_addr);
 334         }
 335         return 0;
 336     }
 337
 338     /* looks good */
 339     return 1;
 340 }
 341
 342 #define MAX_STACK_POINTERS 256
 343 lispobj *valid_stack_locations[MAX_STACK_POINTERS];
 344 unsigned int num_valid_stack_locations;
 345
 346 #define MAX_STACK_RETURN_ADDRESSES 128
 347 lispobj *valid_stack_ra_locations[MAX_STACK_RETURN_ADDRESSES];
 348 lispobj *valid_stack_ra_code_objects[MAX_STACK_RETURN_ADDRESSES];
 349 unsigned int num_valid_stack_ra_locations;
 350
 351 /* Identify valid stack slots. */
 352 static void
 353 setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
 354 {
 355     lispobj *sp = lowaddr;
 356     num_valid_stack_locations = 0;
 357     num_valid_stack_ra_locations = 0;
 358     for (sp = lowaddr; sp < base; sp++) {
 359         lispobj thing = *sp;
 360         /* Find the object start address */
 361         lispobj *start_addr = search_dynamic_space((void *)thing);
 362         if (start_addr) {
 363             /* We need to allow raw pointers into Code objects for
 364              * return addresses. This will also pick up pointers to
 365              * functions in code objects. */
 366             if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
 367                 /* FIXME asserting here is a really dumb thing to do.
 368                  * If we've overflowed some arbitrary static limit, we
 369                  * should just refuse to purify, instead of killing
 370                  * the whole lisp session
 371                  */
 372                 gc_assert(num_valid_stack_ra_locations <
 373                           MAX_STACK_RETURN_ADDRESSES);
 374                 valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
 375                 valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
 376                     (lispobj *)((int)start_addr + OTHER_POINTER_LOWTAG);
 377             } else {
 378                 if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
 379                     gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
 380                     valid_stack_locations[num_valid_stack_locations++] = sp;
 381                 }
 382             }
 383         }
 384     }
 385     if (pointer_filter_verbose) {
 386         fprintf(stderr, "number of valid stack pointers = %d\n",
 387                 num_valid_stack_locations);
 388         fprintf(stderr, "number of stack return addresses = %d\n",
 389                 num_valid_stack_ra_locations);
 390     }
 391 }
 392
 393 static void
 394 pscav_i386_stack(void)
 395 {
 396     int i;
 397
 398     for (i = 0; i < num_valid_stack_locations; i++)
 399         pscav(valid_stack_locations[i], 1, 0);
 400
 401     for (i = 0; i < num_valid_stack_ra_locations; i++) {
 402         lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
 403         pscav(&code_obj, 1, 0);
 404         if (pointer_filter_verbose) {
 405             fprintf(stderr,"*C moved RA %x to %x; for code object %x to %x\n",
 406                     *valid_stack_ra_locations[i],
 407                     (int)(*valid_stack_ra_locations[i])
 408                     - ((int)valid_stack_ra_code_objects[i] - (int)code_obj),
 409                     (unsigned int) valid_stack_ra_code_objects[i], code_obj);
 410         }
 411         *valid_stack_ra_locations[i] =
 412             ((int)(*valid_stack_ra_locations[i])
 413              - ((int)valid_stack_ra_code_objects[i] - (int)code_obj));
 414     }
 415 }
 416 #endif
 417 #endif
 418
 419 \f
 420 static void
 421 pscav_later(lispobj *where, int count)
 422 {
 423     struct later *new;
 424
 425     if (count > LATERMAXCOUNT) {
 426         while (count > LATERMAXCOUNT) {
 427             pscav_later(where, LATERMAXCOUNT);
 428             count -= LATERMAXCOUNT;
 429             where += LATERMAXCOUNT;
 430         }
 431     }
 432     else {
 433         if (later_blocks == NULL || later_count == LATERBLOCKSIZE ||
 434             (later_count == LATERBLOCKSIZE-1 && count > 1)) {
 435             new  = (struct later *)malloc(sizeof(struct later));
 436             new->next = later_blocks;
 437             if (later_blocks && later_count < LATERBLOCKSIZE)
 438                 later_blocks->u[later_count].ptr = NULL;
 439             later_blocks = new;
 440             later_count = 0;
 441         }
 442
 443         if (count != 1)
 444             later_blocks->u[later_count++].count = count;
 445         later_blocks->u[later_count++].ptr = where;
 446     }
 447 }
 448
 449 static lispobj
 450 ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 451 {
 452     int nwords;
 453     lispobj result, *new, *old;
 454
 455     nwords = 1 + HeaderValue(header);
 456
 457     /* Allocate it */
 458     old = (lispobj *)native_pointer(thing);
 459     if (constant) {
 460         new = read_only_free;
 461         read_only_free += CEILING(nwords, 2);
 462     }
 463     else {
 464         new = static_free;
 465         static_free += CEILING(nwords, 2);
 466     }
 467
 468     /* Copy it. */
 469     bcopy(old, new, nwords * sizeof(lispobj));
 470
 471     /* Deposit forwarding pointer. */
 472     result = make_lispobj(new, lowtag_of(thing));
 473     *old = result;
 474
 475     /* Scavenge it. */
 476     pscav(new, nwords, constant);
 477
 478     return result;
 479 }
 480
 481 /* We need to look at the layout to see whether it is a pure structure
 482  * class, and only then can we transport as constant. If it is pure,
 483  * we can ALWAYS transport as a constant. */
 484 static lispobj
 485 ptrans_instance(lispobj thing, lispobj header, boolean constant)
 486 {
 487     lispobj layout = ((struct instance *)native_pointer(thing))->slots[0];
 488     lispobj pure = ((struct instance *)native_pointer(layout))->slots[15];
 489
 490     switch (pure) {
 491     case T:
 492         return (ptrans_boxed(thing, header, 1));
 493     case NIL:
 494         return (ptrans_boxed(thing, header, 0));
 495     case 0:
 496         {
 497             /* Substructure: special case for the COMPACT-INFO-ENVs,
 498              * where the instance may have a point to the dynamic
 499              * space placed into it (e.g. the cache-name slot), but
 500              * the lists and arrays at the time of a purify can be
 501              * moved to the RO space. */
 502             int nwords;
 503             lispobj result, *new, *old;
 504
 505             nwords = 1 + HeaderValue(header);
 506
 507             /* Allocate it */
 508             old = (lispobj *)native_pointer(thing);
 509             new = static_free;
 510             static_free += CEILING(nwords, 2);
 511
 512             /* Copy it. */
 513             bcopy(old, new, nwords * sizeof(lispobj));
 514
 515             /* Deposit forwarding pointer. */
 516             result = make_lispobj(new, lowtag_of(thing));
 517             *old = result;
 518
 519             /* Scavenge it. */
 520             pscav(new, nwords, 1);
 521
 522             return result;
 523         }
 524     default:
 525         gc_abort();
 526         return NIL; /* dummy value: return something ... */
 527     }
 528 }
 529
 530 static lispobj
 531 ptrans_fdefn(lispobj thing, lispobj header)
 532 {
 533     int nwords;
 534     lispobj result, *new, *old, oldfn;
 535     struct fdefn *fdefn;
 536
 537     nwords = 1 + HeaderValue(header);
 538
 539     /* Allocate it */
 540     old = (lispobj *)native_pointer(thing);
 541     new = static_free;
 542     static_free += CEILING(nwords, 2);
 543
 544     /* Copy it. */
 545     bcopy(old, new, nwords * sizeof(lispobj));
 546
 547     /* Deposit forwarding pointer. */
 548     result = make_lispobj(new, lowtag_of(thing));
 549     *old = result;
 550
 551     /* Scavenge the function. */
 552     fdefn = (struct fdefn *)new;
 553     oldfn = fdefn->fun;
 554     pscav(&fdefn->fun, 1, 0);
 555     if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
 556         fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 557
 558     return result;
 559 }
 560
 561 static lispobj
 562 ptrans_unboxed(lispobj thing, lispobj header)
 563 {
 564     int nwords;
 565     lispobj result, *new, *old;
 566
 567     nwords = 1 + HeaderValue(header);
 568
 569     /* Allocate it */
 570     old = (lispobj *)native_pointer(thing);
 571     new = read_only_free;
 572     read_only_free += CEILING(nwords, 2);
 573
 574     /* Copy it. */
 575     bcopy(old, new, nwords * sizeof(lispobj));
 576
 577     /* Deposit forwarding pointer. */
 578     result = make_lispobj(new , lowtag_of(thing));
 579     *old = result;
 580
 581     return result;
 582 }
 583
 584 static lispobj
 585 ptrans_vector(lispobj thing, int bits, int extra,
 586               boolean boxed, boolean constant)
 587 {
 588     struct vector *vector;
 589     int nwords;
 590     lispobj result, *new;
 591
 592     vector = (struct vector *)native_pointer(thing);
 593     nwords = 2 + (CEILING((fixnum_value(vector->length)+extra)*bits,32)>>5);
 594
 595     if (boxed && !constant) {
 596         new = static_free;
 597         static_free += CEILING(nwords, 2);
 598     }
 599     else {
 600         new = read_only_free;
 601         read_only_free += CEILING(nwords, 2);
 602     }
 603
 604     bcopy(vector, new, nwords * sizeof(lispobj));
 605
 606     result = make_lispobj(new, lowtag_of(thing));
 607     vector->header = result;
 608
 609     if (boxed)
 610         pscav(new, nwords, constant);
 611
 612     return result;
 613 }
 614
 615 #ifdef __i386__
 616 static void
 617 apply_code_fixups_during_purify(struct code *old_code, struct code *new_code)
 618 {
 619     int nheader_words, ncode_words, nwords;
 620     void  *constants_start_addr, *constants_end_addr;
 621     void  *code_start_addr, *code_end_addr;
 622     lispobj fixups = NIL;
 623     unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
 624     struct vector *fixups_vector;
 625
 626     ncode_words = fixnum_value(new_code->code_size);
 627     nheader_words = HeaderValue(*(lispobj *)new_code);
 628     nwords = ncode_words + nheader_words;
 629
 630     constants_start_addr = (void *)new_code + 5*4;
 631     constants_end_addr = (void *)new_code + nheader_words*4;
 632     code_start_addr = (void *)new_code + nheader_words*4;
 633     code_end_addr = (void *)new_code + nwords*4;
 634
 635     /* The first constant should be a pointer to the fixups for this
 636      * code objects. Check. */
 637     fixups = new_code->constants[0];
 638
 639     /* It will be 0 or the unbound-marker if there are no fixups, and
 640      * will be an other-pointer to a vector if it is valid. */
 641     if ((fixups==0) ||
 642         (fixups==UNBOUND_MARKER_WIDETAG) ||
 643         !is_lisp_pointer(fixups)) {
 644 #ifdef LISP_FEATURE_GENCGC
 645         /* Check for a possible errors. */
 646         sniff_code_object(new_code,displacement);
 647 #endif
 648         return;
 649     }
 650
 651     fixups_vector = (struct vector *)native_pointer(fixups);
 652
 653     /* Could be pointing to a forwarding pointer. */
 654     if (is_lisp_pointer(fixups) && (dynamic_pointer_p(fixups))
 655         && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
 656         /* If so then follow it. */
 657         fixups_vector =
 658             (struct vector *)native_pointer(*(lispobj *)fixups_vector);
 659     }
 660
 661     if (widetag_of(fixups_vector->header) ==
 662         SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
 663         /* We got the fixups for the code block. Now work through the
 664          * vector, and apply a fixup at each address. */
 665         int length = fixnum_value(fixups_vector->length);
 666         int i;
 667         for (i=0; i<length; i++) {
 668             unsigned offset = fixups_vector->data[i];
 669             /* Now check the current value of offset. */
 670             unsigned old_value =
 671                 *(unsigned *)((unsigned)code_start_addr + offset);
 672
 673             /* If it's within the old_code object then it must be an
 674              * absolute fixup (relative ones are not saved) */
 675             if ((old_value>=(unsigned)old_code)
 676                 && (old_value<((unsigned)old_code + nwords*4)))
 677                 /* So add the dispacement. */
 678                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 679                     + displacement;
 680             else
 681                 /* It is outside the old code object so it must be a relative
 682                  * fixup (absolute fixups are not saved). So subtract the
 683                  * displacement. */
 684                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 685                     - displacement;
 686         }
 687     }
 688
 689     /* No longer need the fixups. */
 690     new_code->constants[0] = 0;
 691
 692 #ifdef LISP_FEATURE_GENCGC
 693     /* Check for possible errors. */
 694     sniff_code_object(new_code,displacement);
 695 #endif
 696 }
 697 #endif
 698
 699 static lispobj
 700 ptrans_code(lispobj thing)
 701 {
 702     struct code *code, *new;
 703     int nwords;
 704     lispobj func, result;
 705
 706     code = (struct code *)native_pointer(thing);
 707     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
 708
 709     new = (struct code *)read_only_free;
 710     read_only_free += CEILING(nwords, 2);
 711
 712     bcopy(code, new, nwords * sizeof(lispobj));
 713
 714 #ifdef LISP_FEATURE_X86
 715     apply_code_fixups_during_purify(code,new);
 716 #endif
 717
 718     result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 719
 720     /* Stick in a forwarding pointer for the code object. */
 721     *(lispobj *)code = result;
 722
 723     /* Put in forwarding pointers for all the functions. */
 724     for (func = code->entry_points;
 725          func != NIL;
 726          func = ((struct simple_fun *)native_pointer(func))->next) {
 727
 728         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 729
 730         *(lispobj *)native_pointer(func) = result + (func - thing);
 731     }
 732
 733     /* Arrange to scavenge the debug info later. */
 734     pscav_later(&new->debug_info, 1);
 735
 736     if (new->trace_table_offset & 0x3)
 737 #if 0
 738       pscav(&new->trace_table_offset, 1, 0);
 739 #else
 740       new->trace_table_offset = NIL; /* limit lifetime */
 741 #endif
 742
 743     /* Scavenge the constants. */
 744     pscav(new->constants, HeaderValue(new->header)-5, 1);
 745
 746     /* Scavenge all the functions. */
 747     pscav(&new->entry_points, 1, 1);
 748     for (func = new->entry_points;
 749          func != NIL;
 750          func = ((struct simple_fun *)native_pointer(func))->next) {
 751         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 752         gc_assert(!dynamic_pointer_p(func));
 753
 754 #ifdef __i386__
 755         /* Temporarly convert the self pointer to a real function pointer. */
 756         ((struct simple_fun *)native_pointer(func))->self
 757             -= FUN_RAW_ADDR_OFFSET;
 758 #endif
 759         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 760 #ifdef __i386__
 761         ((struct simple_fun *)native_pointer(func))->self
 762             += FUN_RAW_ADDR_OFFSET;
 763 #endif
 764         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
 765     }
 766
 767     return result;
 768 }
 769
 770 static lispobj
 771 ptrans_func(lispobj thing, lispobj header)
 772 {
 773     int nwords;
 774     lispobj code, *new, *old, result;
 775     struct simple_fun *function;
 776
 777     /* Thing can either be a function header, a closure function
 778      * header, a closure, or a funcallable-instance. If it's a closure
 779      * or a funcallable-instance, we do the same as ptrans_boxed.
 780      * Otherwise we have to do something strange, 'cause it is buried
 781      * inside a code object. */
 782
 783     if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG ||
 784         widetag_of(header) == CLOSURE_FUN_HEADER_WIDETAG) {
 785
 786         /* We can only end up here if the code object has not been
 787          * scavenged, because if it had been scavenged, forwarding pointers
 788          * would have been left behind for all the entry points. */
 789
 790         function = (struct simple_fun *)native_pointer(thing);
 791         code =
 792             make_lispobj
 793             ((native_pointer(thing) -
 794               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 795
 796         /* This will cause the function's header to be replaced with a
 797          * forwarding pointer. */
 798
 799         ptrans_code(code);
 800
 801         /* So we can just return that. */
 802         return function->header;
 803     }
 804     else {
 805         /* It's some kind of closure-like thing. */
 806         nwords = 1 + HeaderValue(header);
 807         old = (lispobj *)native_pointer(thing);
 808
 809         /* Allocate the new one. */
 810         if (widetag_of(header) == FUNCALLABLE_INSTANCE_HEADER_WIDETAG) {
 811             /* FINs *must* not go in read_only space. */
 812             new = static_free;
 813             static_free += CEILING(nwords, 2);
 814         }
 815         else {
 816             /* Closures can always go in read-only space, 'cause they
 817              * never change. */
 818
 819             new = read_only_free;
 820             read_only_free += CEILING(nwords, 2);
 821         }
 822         /* Copy it. */
 823         bcopy(old, new, nwords * sizeof(lispobj));
 824
 825         /* Deposit forwarding pointer. */
 826         result = make_lispobj(new, lowtag_of(thing));
 827         *old = result;
 828
 829         /* Scavenge it. */
 830         pscav(new, nwords, 0);
 831
 832         return result;
 833     }
 834 }
 835
 836 static lispobj
 837 ptrans_returnpc(lispobj thing, lispobj header)
 838 {
 839     lispobj code, new;
 840
 841     /* Find the corresponding code object. */
 842     code = thing - HeaderValue(header)*sizeof(lispobj);
 843
 844     /* Make sure it's been transported. */
 845     new = *(lispobj *)native_pointer(code);
 846     if (!forwarding_pointer_p(new))
 847         new = ptrans_code(code);
 848
 849     /* Maintain the offset: */
 850     return new + (thing - code);
 851 }
 852
 853 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 854
 855 static lispobj
 856 ptrans_list(lispobj thing, boolean constant)
 857 {
 858     struct cons *old, *new, *orig;
 859     int length;
 860
 861     if (constant)
 862         orig = (struct cons *)read_only_free;
 863     else
 864         orig = (struct cons *)static_free;
 865     length = 0;
 866
 867     do {
 868         /* Allocate a new cons cell. */
 869         old = (struct cons *)native_pointer(thing);
 870         if (constant) {
 871             new = (struct cons *)read_only_free;
 872             read_only_free += WORDS_PER_CONS;
 873         }
 874         else {
 875             new = (struct cons *)static_free;
 876             static_free += WORDS_PER_CONS;
 877         }
 878
 879         /* Copy the cons cell and keep a pointer to the cdr. */
 880         new->car = old->car;
 881         thing = new->cdr = old->cdr;
 882
 883         /* Set up the forwarding pointer. */
 884         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 885
 886         /* And count this cell. */
 887         length++;
 888     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 889              dynamic_pointer_p(thing) &&
 890              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 891
 892     /* Scavenge the list we just copied. */
 893     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 894
 895     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 896 }
 897
 898 static lispobj
 899 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 900 {
 901     switch (widetag_of(header)) {
 902       case BIGNUM_WIDETAG:
 903       case SINGLE_FLOAT_WIDETAG:
 904       case DOUBLE_FLOAT_WIDETAG:
 905 #ifdef LONG_FLOAT_WIDETAG
 906       case LONG_FLOAT_WIDETAG:
 907 #endif
 908 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 909       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 910 #endif
 911 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 912       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 913 #endif
 914 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 915       case COMPLEX_LONG_FLOAT_WIDETAG:
 916 #endif
 917       case SAP_WIDETAG:
 918         return ptrans_unboxed(thing, header);
 919
 920       case RATIO_WIDETAG:
 921       case COMPLEX_WIDETAG:
 922       case SIMPLE_ARRAY_WIDETAG:
 923       case COMPLEX_STRING_WIDETAG:
 924       case COMPLEX_VECTOR_WIDETAG:
 925       case COMPLEX_ARRAY_WIDETAG:
 926         return ptrans_boxed(thing, header, constant);
 927
 928       case VALUE_CELL_HEADER_WIDETAG:
 929       case WEAK_POINTER_WIDETAG:
 930         return ptrans_boxed(thing, header, 0);
 931
 932       case SYMBOL_HEADER_WIDETAG:
 933         return ptrans_boxed(thing, header, 0);
 934
 935       case SIMPLE_STRING_WIDETAG:
 936         return ptrans_vector(thing, 8, 1, 0, constant);
 937
 938       case SIMPLE_BIT_VECTOR_WIDETAG:
 939         return ptrans_vector(thing, 1, 0, 0, constant);
 940
 941       case SIMPLE_VECTOR_WIDETAG:
 942         return ptrans_vector(thing, 32, 0, 1, constant);
 943
 944       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 945         return ptrans_vector(thing, 2, 0, 0, constant);
 946
 947       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 948         return ptrans_vector(thing, 4, 0, 0, constant);
 949
 950       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 951 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 952       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 953 #endif
 954         return ptrans_vector(thing, 8, 0, 0, constant);
 955
 956       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 957 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 958       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 959 #endif
 960         return ptrans_vector(thing, 16, 0, 0, constant);
 961
 962       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 963 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 964       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 965 #endif
 966 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 967       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 968 #endif
 969         return ptrans_vector(thing, 32, 0, 0, constant);
 970
 971       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 972         return ptrans_vector(thing, 32, 0, 0, constant);
 973
 974       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 975         return ptrans_vector(thing, 64, 0, 0, constant);
 976
 977 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 978       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 979 #ifdef __i386__
 980         return ptrans_vector(thing, 96, 0, 0, constant);
 981 #endif
 982 #ifdef sparc
 983         return ptrans_vector(thing, 128, 0, 0, constant);
 984 #endif
 985 #endif
 986
 987 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 988       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 989         return ptrans_vector(thing, 64, 0, 0, constant);
 990 #endif
 991
 992 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 993       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 994         return ptrans_vector(thing, 128, 0, 0, constant);
 995 #endif
 996
 997 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 998       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 999 #ifdef __i386__
1000         return ptrans_vector(thing, 192, 0, 0, constant);
1001 #endif
1002 #ifdef sparc
1003         return ptrans_vector(thing, 256, 0, 0, constant);
1004 #endif
1005 #endif
1006
1007       case CODE_HEADER_WIDETAG:
1008         return ptrans_code(thing);
1009
1010       case RETURN_PC_HEADER_WIDETAG:
1011         return ptrans_returnpc(thing, header);
1012
1013       case FDEFN_WIDETAG:
1014         return ptrans_fdefn(thing, header);
1015
1016       default:
1017         /* Should only come across other pointers to the above stuff. */
1018         gc_abort();
1019         return NIL;
1020     }
1021 }
1022
1023 static int
1024 pscav_fdefn(struct fdefn *fdefn)
1025 {
1026     boolean fix_func;
1027
1028     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
1029     pscav(&fdefn->name, 1, 1);
1030     pscav(&fdefn->fun, 1, 0);
1031     if (fix_func)
1032         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
1033     return sizeof(struct fdefn) / sizeof(lispobj);
1034 }
1035
1036 #ifdef __i386__
1037 /* now putting code objects in static space */
1038 static int
1039 pscav_code(struct code*code)
1040 {
1041     int nwords;
1042     lispobj func;
1043     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
1044
1045     /* Arrange to scavenge the debug info later. */
1046     pscav_later(&code->debug_info, 1);
1047
1048     /* Scavenge the constants. */
1049     pscav(code->constants, HeaderValue(code->header)-5, 1);
1050
1051     /* Scavenge all the functions. */
1052     pscav(&code->entry_points, 1, 1);
1053     for (func = code->entry_points;
1054          func != NIL;
1055          func = ((struct simple_fun *)native_pointer(func))->next) {
1056         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
1057         gc_assert(!dynamic_pointer_p(func));
1058
1059 #ifdef __i386__
1060         /* Temporarly convert the self pointer to a real function
1061          * pointer. */
1062         ((struct simple_fun *)native_pointer(func))->self
1063             -= FUN_RAW_ADDR_OFFSET;
1064 #endif
1065         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
1066 #ifdef __i386__
1067         ((struct simple_fun *)native_pointer(func))->self
1068             += FUN_RAW_ADDR_OFFSET;
1069 #endif
1070         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
1071     }
1072
1073     return CEILING(nwords,2);
1074 }
1075 #endif
1076
1077 static lispobj *
1078 pscav(lispobj *addr, int nwords, boolean constant)
1079 {
1080     lispobj thing, *thingp, header;
1081     int count = 0; /* (0 = dummy init value to stop GCC warning) */
1082     struct vector *vector;
1083
1084     while (nwords > 0) {
1085         thing = *addr;
1086         if (is_lisp_pointer(thing)) {
1087             /* It's a pointer. Is it something we might have to move? */
1088             if (dynamic_pointer_p(thing)) {
1089                 /* Maybe. Have we already moved it? */
1090                 thingp = (lispobj *)native_pointer(thing);
1091                 header = *thingp;
1092                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
1093                     /* Yep, so just copy the forwarding pointer. */
1094                     thing = header;
1095                 else {
1096                     /* Nope, copy the object. */
1097                     switch (lowtag_of(thing)) {
1098                       case FUN_POINTER_LOWTAG:
1099                         thing = ptrans_func(thing, header);
1100                         break;
1101
1102                       case LIST_POINTER_LOWTAG:
1103                         thing = ptrans_list(thing, constant);
1104                         break;
1105
1106                       case INSTANCE_POINTER_LOWTAG:
1107                         thing = ptrans_instance(thing, header, constant);
1108                         break;
1109
1110                       case OTHER_POINTER_LOWTAG:
1111                         thing = ptrans_otherptr(thing, header, constant);
1112                         break;
1113
1114                       default:
1115                         /* It was a pointer, but not one of them? */
1116                         gc_abort();
1117                     }
1118                 }
1119                 *addr = thing;
1120             }
1121             count = 1;
1122         }
1123         else if (thing & 3) {
1124             /* It's an other immediate. Maybe the header for an unboxed */
1125             /* object. */
1126             switch (widetag_of(thing)) {
1127               case BIGNUM_WIDETAG:
1128               case SINGLE_FLOAT_WIDETAG:
1129               case DOUBLE_FLOAT_WIDETAG:
1130 #ifdef LONG_FLOAT_WIDETAG
1131               case LONG_FLOAT_WIDETAG:
1132 #endif
1133               case SAP_WIDETAG:
1134                 /* It's an unboxed simple object. */
1135                 count = HeaderValue(thing)+1;
1136                 break;
1137
1138               case SIMPLE_VECTOR_WIDETAG:
1139                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
1140                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
1141                         SIMPLE_VECTOR_WIDETAG;
1142                   }
1143                 count = 1;
1144                 break;
1145
1146               case SIMPLE_STRING_WIDETAG:
1147                 vector = (struct vector *)addr;
1148                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,4)+2,2);
1149                 break;
1150
1151               case SIMPLE_BIT_VECTOR_WIDETAG:
1152                 vector = (struct vector *)addr;
1153                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
1154                 break;
1155
1156               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1157                 vector = (struct vector *)addr;
1158                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
1159                 break;
1160
1161               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1162                 vector = (struct vector *)addr;
1163                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
1164                 break;
1165
1166               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1167 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1168               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1169 #endif
1170                 vector = (struct vector *)addr;
1171                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
1172                 break;
1173
1174               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1175 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1176               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1177 #endif
1178                 vector = (struct vector *)addr;
1179                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
1180                 break;
1181
1182               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1183 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1184               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1185 #endif
1186 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1187               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1188 #endif
1189                 vector = (struct vector *)addr;
1190                 count = CEILING(fixnum_value(vector->length)+2,2);
1191                 break;
1192
1193               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1194                 vector = (struct vector *)addr;
1195                 count = CEILING(fixnum_value(vector->length)+2,2);
1196                 break;
1197
1198               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1199 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1200               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1201 #endif
1202                 vector = (struct vector *)addr;
1203                 count = fixnum_value(vector->length)*2+2;
1204                 break;
1205
1206 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1207               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1208                 vector = (struct vector *)addr;
1209 #ifdef __i386__
1210                 count = fixnum_value(vector->length)*3+2;
1211 #endif
1212 #ifdef sparc
1213                 count = fixnum_value(vector->length)*4+2;
1214 #endif
1215                 break;
1216 #endif
1217
1218 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1219               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1220                 vector = (struct vector *)addr;
1221                 count = fixnum_value(vector->length)*4+2;
1222                 break;
1223 #endif
1224
1225 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1226               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1227                 vector = (struct vector *)addr;
1228 #ifdef __i386__
1229                 count = fixnum_value(vector->length)*6+2;
1230 #endif
1231 #ifdef sparc
1232                 count = fixnum_value(vector->length)*8+2;
1233 #endif
1234                 break;
1235 #endif
1236
1237               case CODE_HEADER_WIDETAG:
1238 #ifndef __i386__
1239                 gc_abort(); /* no code headers in static space */
1240 #else
1241                 count = pscav_code((struct code*)addr);
1242 #endif
1243                 break;
1244
1245               case SIMPLE_FUN_HEADER_WIDETAG:
1246               case CLOSURE_FUN_HEADER_WIDETAG:
1247               case RETURN_PC_HEADER_WIDETAG:
1248                 /* We should never hit any of these, 'cause they occur
1249                  * buried in the middle of code objects. */
1250                 gc_abort();
1251                 break;
1252
1253 #ifdef __i386__
1254               case CLOSURE_HEADER_WIDETAG:
1255               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
1256                 /* The function self pointer needs special care on the
1257                  * x86 because it is the real entry point. */
1258                 {
1259                   lispobj fun = ((struct closure *)addr)->fun
1260                     - FUN_RAW_ADDR_OFFSET;
1261                   pscav(&fun, 1, constant);
1262                   ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
1263                 }
1264                 count = 2;
1265                 break;
1266 #endif
1267
1268               case WEAK_POINTER_WIDETAG:
1269                 /* Weak pointers get preserved during purify, 'cause I
1270                  * don't feel like figuring out how to break them. */
1271                 pscav(addr+1, 2, constant);
1272                 count = 4;
1273                 break;
1274
1275               case FDEFN_WIDETAG:
1276                 /* We have to handle fdefn objects specially, so we
1277                  * can fix up the raw function address. */
1278                 count = pscav_fdefn((struct fdefn *)addr);
1279                 break;
1280
1281               default:
1282                 count = 1;
1283                 break;
1284             }
1285         }
1286         else {
1287             /* It's a fixnum. */
1288             count = 1;
1289         }
1290
1291         addr += count;
1292         nwords -= count;
1293     }
1294
1295     return addr;
1296 }
1297
1298 int
1299 purify(lispobj static_roots, lispobj read_only_roots)
1300 {
1301     lispobj *clean;
1302     int count, i;
1303     struct later *laters, *next;
1304
1305
1306 #ifdef PRINTNOISE
1307     printf("[doing purification:");
1308     fflush(stdout);
1309 #endif
1310 #ifdef LISP_FEATURE_GENCGC
1311     gc_alloc_update_all_page_tables();
1312 #endif
1313     if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX)) != 0) {
1314         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
1315          * its error simply by a. printing a string b. to stdout instead
1316          * of stderr. */
1317         printf(" Ack! Can't purify interrupt contexts. ");
1318         fflush(stdout);
1319         return 0;
1320     }
1321
1322 #if defined(__i386__)
1323     dynamic_space_free_pointer =
1324       (lispobj*)SymbolValue(ALLOCATION_POINTER);
1325 #endif
1326
1327     read_only_end = read_only_free =
1328         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER);
1329     static_end = static_free =
1330         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER);
1331
1332 #ifdef PRINTNOISE
1333     printf(" roots");
1334     fflush(stdout);
1335 #endif
1336
1337 #if (defined(LISP_FEATURE_GENCGC) && defined(LISP_FEATURE_X86))
1338     gc_assert((lispobj *)CONTROL_STACK_END > ((&read_only_roots)+1));
1339     setup_i386_stack_scav(((&static_roots)-2), (lispobj *)CONTROL_STACK_END);
1340 #endif
1341
1342     pscav(&static_roots, 1, 0);
1343     pscav(&read_only_roots, 1, 1);
1344
1345 #ifdef PRINTNOISE
1346     printf(" handlers");
1347     fflush(stdout);
1348 #endif
1349     pscav((lispobj *) interrupt_handlers,
1350           sizeof(interrupt_handlers) / sizeof(lispobj),
1351           0);
1352
1353 #ifdef PRINTNOISE
1354     printf(" stack");
1355     fflush(stdout);
1356 #endif
1357 #ifndef __i386__
1358     pscav((lispobj *)CONTROL_STACK_START,
1359           current_control_stack_pointer - (lispobj *)CONTROL_STACK_START,
1360           0);
1361 #else
1362 #ifdef LISP_FEATURE_GENCGC
1363     pscav_i386_stack();
1364 #endif
1365 #endif
1366
1367 #ifdef PRINTNOISE
1368     printf(" bindings");
1369     fflush(stdout);
1370 #endif
1371 #if !defined(__i386__)
1372     pscav( (lispobj *)BINDING_STACK_START,
1373           (lispobj *)current_binding_stack_pointer - (lispobj *)BINDING_STACK_START,
1374           0);
1375 #else
1376     pscav( (lispobj *)BINDING_STACK_START,
1377           (lispobj *)SymbolValue(BINDING_STACK_POINTER) -
1378           (lispobj *)BINDING_STACK_START,
1379           0);
1380 #endif
1381
1382     /* The original CMU CL code had scavenge-read-only-space code
1383      * controlled by the Lisp-level variable
1384      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
1385      * wasn't documented under what circumstances it was useful or
1386      * safe to turn it on, so it's been turned off in SBCL. If you
1387      * want/need this functionality, and can test and document it,
1388      * please submit a patch. */
1389 #if 0
1390     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
1391         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
1392       unsigned  read_only_space_size =
1393           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
1394           (lispobj *)READ_ONLY_SPACE_START;
1395       fprintf(stderr,
1396               "scavenging read only space: %d bytes\n",
1397               read_only_space_size * sizeof(lispobj));
1398       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
1399     }
1400 #endif
1401
1402 #ifdef PRINTNOISE
1403     printf(" static");
1404     fflush(stdout);
1405 #endif
1406     clean = (lispobj *)STATIC_SPACE_START;
1407     do {
1408         while (clean != static_free)
1409             clean = pscav(clean, static_free - clean, 0);
1410         laters = later_blocks;
1411         count = later_count;
1412         later_blocks = NULL;
1413         later_count = 0;
1414         while (laters != NULL) {
1415             for (i = 0; i < count; i++) {
1416                 if (laters->u[i].count == 0) {
1417                     ;
1418                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1419                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1420                     i++;
1421                 } else {
1422                     pscav(laters->u[i].ptr, 1, 1);
1423                 }
1424             }
1425             next = laters->next;
1426             free(laters);
1427             laters = next;
1428             count = LATERBLOCKSIZE;
1429         }
1430     } while (clean != static_free || later_blocks != NULL);
1431
1432 #ifdef PRINTNOISE
1433     printf(" cleanup");
1434     fflush(stdout);
1435 #endif
1436
1437     os_zero((os_vm_address_t) current_dynamic_space,
1438             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
1439
1440     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
1441      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
1442 #ifndef __i386__
1443     os_zero((os_vm_address_t) current_control_stack_pointer,
1444             (os_vm_size_t) (CONTROL_STACK_SIZE -
1445                             ((current_control_stack_pointer -
1446                               (lispobj *)CONTROL_STACK_START) *
1447                              sizeof(lispobj))));
1448 #endif
1449
1450     /* It helps to update the heap free pointers so that free_heap can
1451      * verify after it's done. */
1452     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free);
1453     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free);
1454
1455 #if !defined(__i386__)
1456     dynamic_space_free_pointer = current_dynamic_space;
1457 #else
1458 #if defined LISP_FEATURE_GENCGC
1459     gc_free_heap();
1460 #else
1461 #error unsupported case /* in CMU CL, was "ibmrt using GC" */
1462 #endif
1463 #endif
1464
1465 #ifdef PRINTNOISE
1466     printf(" done]\n");
1467     fflush(stdout);
1468 #endif
1469
1470     return 0;
1471 }