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
  38 #define PRINTNOISE
  39
  40 #if defined(LISP_FEATURE_GENCGC)
  41 /* this is another artifact of the poor integration between gencgc and
  42  * the rest of the runtime: on cheney gc there is a global
  43  * dynamic_space_free_pointer which is valid whenever foreign function
  44  * call is active, but in gencgc there's no such variable and we have
  45  * to keep our own
  46  */
  47 static lispobj *dynamic_space_free_pointer;
  48 #endif
  49 extern unsigned long bytes_consed_between_gcs;
  50
  51 #define gc_abort() \
  52   lose("GC invariant lost, file \"%s\", line %d", __FILE__, __LINE__)
  53
  54 #if 1
  55 #define gc_assert(ex) do { \
  56         if (!(ex)) gc_abort(); \
  57 } while (0)
  58 #else
  59 #define gc_assert(ex)
  60 #endif
  61
  62 \f
  63 /* These hold the original end of the read_only and static spaces so
  64  * we can tell what are forwarding pointers. */
  65
  66 static lispobj *read_only_end, *static_end;
  67
  68 static lispobj *read_only_free, *static_free;
  69
  70 static lispobj *pscav(lispobj *addr, long nwords, boolean constant);
  71
  72 #define LATERBLOCKSIZE 1020
  73 #define LATERMAXCOUNT 10
  74
  75 static struct
  76 later {
  77     struct later *next;
  78     union {
  79         lispobj *ptr;
  80         long count;
  81     } u[LATERBLOCKSIZE];
  82 } *later_blocks = NULL;
  83 static long later_count = 0;
  84
  85 #if N_WORD_BITS == 32
  86  #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
  87 #elif N_WORD_BITS == 64
  88  #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
  89 #endif
  90
  91 /* FIXME: Shouldn't this be defined in sbcl.h?  See also notes in
  92  * cheneygc.c */
  93
  94 #ifdef LISP_FEATURE_SPARC
  95 #define FUN_RAW_ADDR_OFFSET 0
  96 #else
  97 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
  98 #endif
  99 \f
 100 static boolean
 101 forwarding_pointer_p(lispobj obj)
 102 {
 103     lispobj *ptr = native_pointer(obj);
 104
 105     return ((static_end <= ptr && ptr <= static_free) ||
 106             (read_only_end <= ptr && ptr <= read_only_free));
 107 }
 108
 109 static boolean
 110 dynamic_pointer_p(lispobj ptr)
 111 {
 112 #ifndef LISP_FEATURE_GENCGC
 113     return (ptr >= (lispobj)current_dynamic_space
 114             &&
 115             ptr < (lispobj)dynamic_space_free_pointer);
 116 #else
 117     /* Be more conservative, and remember, this is a maybe. */
 118     return (ptr >= (lispobj)DYNAMIC_SPACE_START
 119             &&
 120             ptr < (lispobj)dynamic_space_free_pointer);
 121 #endif
 122 }
 123
 124 static inline lispobj *
 125 newspace_alloc(long nwords, int constantp)
 126 {
 127     lispobj *ret;
 128     nwords=CEILING(nwords,2);
 129     if(constantp) {
 130         if(read_only_free + nwords >= (lispobj *)READ_ONLY_SPACE_END) {
 131             lose("Ran out of read-only space while purifying!");
 132         }
 133         ret=read_only_free;
 134         read_only_free+=nwords;
 135     } else {
 136         if(static_free + nwords >= (lispobj *)STATIC_SPACE_END) {
 137             lose("Ran out of static space while purifying!");
 138         }
 139         ret=static_free;
 140         static_free+=nwords;
 141     }
 142     return ret;
 143 }
 144
 145
 146 \f
 147 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 148
 149 #ifdef LISP_FEATURE_GENCGC
 150 /*
 151  * enhanced x86/GENCGC stack scavenging by Douglas Crosher
 152  *
 153  * Scavenging the stack on the i386 is problematic due to conservative
 154  * roots and raw return addresses. Here it is handled in two passes:
 155  * the first pass runs before any objects are moved and tries to
 156  * identify valid pointers and return address on the stack, the second
 157  * pass scavenges these.
 158  */
 159
 160 static unsigned pointer_filter_verbose = 0;
 161
 162 /* FIXME: This is substantially the same code as
 163  * possibly_valid_dynamic_space_pointer in gencgc.c.  The only
 164  * relevant difference seems to be that the gencgc code also checks
 165  * for raw pointers into Code objects, whereas in purify these are
 166  * checked separately in setup_i386_stack_scav - they go onto
 167  * valid_stack_ra_locations instead of just valid_stack_locations */
 168
 169 static int
 170 valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
 171 {
 172     /* If it's not a return address then it needs to be a valid Lisp
 173      * pointer. */
 174     if (!is_lisp_pointer((lispobj)pointer))
 175         return 0;
 176
 177     /* Check that the object pointed to is consistent with the pointer
 178      * low tag. */
 179     switch (lowtag_of((lispobj)pointer)) {
 180     case FUN_POINTER_LOWTAG:
 181         /* Start_addr should be the enclosing code object, or a closure
 182          * header. */
 183         switch (widetag_of(*start_addr)) {
 184         case CODE_HEADER_WIDETAG:
 185             /* This case is probably caught above. */
 186             break;
 187         case CLOSURE_HEADER_WIDETAG:
 188         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 189             if ((long)pointer != ((long)start_addr+FUN_POINTER_LOWTAG)) {
 190                 if (pointer_filter_verbose) {
 191                     fprintf(stderr,"*Wf2: %p %p %p\n",
 192                             pointer, start_addr, (void *)*start_addr);
 193                 }
 194                 return 0;
 195             }
 196             break;
 197         default:
 198             if (pointer_filter_verbose) {
 199                 fprintf(stderr,"*Wf3: %p %p %p\n",
 200                         pointer, start_addr, (void *)*start_addr);
 201             }
 202             return 0;
 203         }
 204         break;
 205     case LIST_POINTER_LOWTAG:
 206         if ((long)pointer != ((long)start_addr+LIST_POINTER_LOWTAG)) {
 207             if (pointer_filter_verbose)
 208                 fprintf(stderr,"*Wl1: %p %p %p\n",
 209                         pointer, start_addr, (void *)*start_addr);
 210             return 0;
 211         }
 212         /* Is it plausible cons? */
 213         if ((is_lisp_pointer(start_addr[0])
 214             || ((start_addr[0] & FIXNUM_TAG_MASK) == 0) /* fixnum */
 215             || (widetag_of(start_addr[0]) == CHARACTER_WIDETAG)
 216 #if N_WORD_BITS == 64
 217             || (widetag_of(start_addr[0]) == SINGLE_FLOAT_WIDETAG)
 218 #endif
 219             || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
 220            && (is_lisp_pointer(start_addr[1])
 221                || ((start_addr[1] & FIXNUM_TAG_MASK) == 0) /* fixnum */
 222                || (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
 223 #if N_WORD_BITS == 64
 224                || (widetag_of(start_addr[1]) == SINGLE_FLOAT_WIDETAG)
 225 #endif
 226                || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
 227             break;
 228         } else {
 229             if (pointer_filter_verbose) {
 230                 fprintf(stderr,"*Wl2: %p %p %p\n",
 231                         pointer, start_addr, (void *)*start_addr);
 232             }
 233             return 0;
 234         }
 235     case INSTANCE_POINTER_LOWTAG:
 236         if ((long)pointer != ((long)start_addr+INSTANCE_POINTER_LOWTAG)) {
 237             if (pointer_filter_verbose) {
 238                 fprintf(stderr,"*Wi1: %p %p %p\n",
 239                         pointer, start_addr, (void *)*start_addr);
 240             }
 241             return 0;
 242         }
 243         if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
 244             if (pointer_filter_verbose) {
 245                 fprintf(stderr,"*Wi2: %p %p %p\n",
 246                         pointer, start_addr, (void *)*start_addr);
 247             }
 248             return 0;
 249         }
 250         break;
 251     case OTHER_POINTER_LOWTAG:
 252         if ((long)pointer != ((long)start_addr+OTHER_POINTER_LOWTAG)) {
 253             if (pointer_filter_verbose) {
 254                 fprintf(stderr,"*Wo1: %p %p %p\n",
 255                         pointer, start_addr, (void *)*start_addr);
 256             }
 257             return 0;
 258         }
 259         /* Is it plausible? Not a cons. XXX should check the headers. */
 260         if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & FIXNUM_TAG_MASK) == 0)) {
 261             if (pointer_filter_verbose) {
 262                 fprintf(stderr,"*Wo2: %p %p %p\n",
 263                         pointer, start_addr, (void *)*start_addr);
 264             }
 265             return 0;
 266         }
 267         switch (widetag_of(start_addr[0])) {
 268         case UNBOUND_MARKER_WIDETAG:
 269         case CHARACTER_WIDETAG:
 270 #if N_WORD_BITS == 64
 271         case SINGLE_FLOAT_WIDETAG:
 272 #endif
 273             if (pointer_filter_verbose) {
 274                 fprintf(stderr,"*Wo3: %p %p %p\n",
 275                         pointer, start_addr, (void *)*start_addr);
 276             }
 277             return 0;
 278
 279             /* only pointed to by function pointers? */
 280         case CLOSURE_HEADER_WIDETAG:
 281         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 282             if (pointer_filter_verbose) {
 283                 fprintf(stderr,"*Wo4: %p %p %p\n",
 284                         pointer, start_addr, (void *)*start_addr);
 285             }
 286             return 0;
 287
 288         case INSTANCE_HEADER_WIDETAG:
 289             if (pointer_filter_verbose) {
 290                 fprintf(stderr,"*Wo5: %p %p %p\n",
 291                         pointer, start_addr, (void *)*start_addr);
 292             }
 293             return 0;
 294
 295             /* the valid other immediate pointer objects */
 296         case SIMPLE_VECTOR_WIDETAG:
 297         case RATIO_WIDETAG:
 298         case COMPLEX_WIDETAG:
 299 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 300         case COMPLEX_SINGLE_FLOAT_WIDETAG:
 301 #endif
 302 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 303         case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 304 #endif
 305 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 306         case COMPLEX_LONG_FLOAT_WIDETAG:
 307 #endif
 308         case SIMPLE_ARRAY_WIDETAG:
 309         case COMPLEX_BASE_STRING_WIDETAG:
 310 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
 311         case COMPLEX_CHARACTER_STRING_WIDETAG:
 312 #endif
 313         case COMPLEX_VECTOR_NIL_WIDETAG:
 314         case COMPLEX_BIT_VECTOR_WIDETAG:
 315         case COMPLEX_VECTOR_WIDETAG:
 316         case COMPLEX_ARRAY_WIDETAG:
 317         case VALUE_CELL_HEADER_WIDETAG:
 318         case SYMBOL_HEADER_WIDETAG:
 319         case FDEFN_WIDETAG:
 320         case CODE_HEADER_WIDETAG:
 321         case BIGNUM_WIDETAG:
 322 #if N_WORD_BITS != 64
 323         case SINGLE_FLOAT_WIDETAG:
 324 #endif
 325         case DOUBLE_FLOAT_WIDETAG:
 326 #ifdef LONG_FLOAT_WIDETAG
 327         case LONG_FLOAT_WIDETAG:
 328 #endif
 329         case SIMPLE_ARRAY_NIL_WIDETAG:
 330         case SIMPLE_BASE_STRING_WIDETAG:
 331 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
 332         case SIMPLE_CHARACTER_STRING_WIDETAG:
 333 #endif
 334         case SIMPLE_BIT_VECTOR_WIDETAG:
 335         case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 336         case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 337         case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 338         case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 339         case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 340         case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 341 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
 342         case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 343 #endif
 344         case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 345         case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 346 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
 347                 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
 348 #endif
 349 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
 350                 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
 351 #endif
 352 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
 353                 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
 354 #endif
 355 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 356         case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 357 #endif
 358 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 359         case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 360 #endif
 361 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 362         case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 363 #endif
 364 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 365         case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 366 #endif
 367 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
 368                 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
 369 #endif
 370 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
 371                 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
 372 #endif
 373         case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 374         case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 375 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 376         case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 377 #endif
 378 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 379         case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 380 #endif
 381 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 382         case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 383 #endif
 384 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 385         case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 386 #endif
 387         case SAP_WIDETAG:
 388         case WEAK_POINTER_WIDETAG:
 389             break;
 390
 391         default:
 392             if (pointer_filter_verbose) {
 393                 fprintf(stderr,"*Wo6: %p %p %p\n",
 394                         pointer, start_addr, (void *)*start_addr);
 395             }
 396             return 0;
 397         }
 398         break;
 399     default:
 400         if (pointer_filter_verbose) {
 401             fprintf(stderr,"*W?: %p %p %p\n",
 402                     pointer, start_addr, (void *)*start_addr);
 403         }
 404         return 0;
 405     }
 406
 407     /* looks good */
 408     return 1;
 409 }
 410
 411 #define MAX_STACK_POINTERS 256
 412 lispobj *valid_stack_locations[MAX_STACK_POINTERS];
 413 unsigned long num_valid_stack_locations;
 414
 415 #define MAX_STACK_RETURN_ADDRESSES 128
 416 lispobj *valid_stack_ra_locations[MAX_STACK_RETURN_ADDRESSES];
 417 lispobj *valid_stack_ra_code_objects[MAX_STACK_RETURN_ADDRESSES];
 418 unsigned long num_valid_stack_ra_locations;
 419
 420 /* Identify valid stack slots. */
 421 static void
 422 setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
 423 {
 424     lispobj *sp = lowaddr;
 425     num_valid_stack_locations = 0;
 426     num_valid_stack_ra_locations = 0;
 427     for (sp = lowaddr; sp < base; sp++) {
 428         lispobj thing = *sp;
 429         /* Find the object start address */
 430         lispobj *start_addr = search_dynamic_space((void *)thing);
 431         if (start_addr) {
 432             /* We need to allow raw pointers into Code objects for
 433              * return addresses. This will also pick up pointers to
 434              * functions in code objects. */
 435             if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
 436                 /* FIXME asserting here is a really dumb thing to do.
 437                  * If we've overflowed some arbitrary static limit, we
 438                  * should just refuse to purify, instead of killing
 439                  * the whole lisp session
 440                  */
 441                 gc_assert(num_valid_stack_ra_locations <
 442                           MAX_STACK_RETURN_ADDRESSES);
 443                 valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
 444                 valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
 445                     (lispobj *)((long)start_addr + OTHER_POINTER_LOWTAG);
 446             } else {
 447                 if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
 448                     gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
 449                     valid_stack_locations[num_valid_stack_locations++] = sp;
 450                 }
 451             }
 452         }
 453     }
 454     if (pointer_filter_verbose) {
 455         fprintf(stderr, "number of valid stack pointers = %ld\n",
 456                 num_valid_stack_locations);
 457         fprintf(stderr, "number of stack return addresses = %ld\n",
 458                 num_valid_stack_ra_locations);
 459     }
 460 }
 461
 462 static void
 463 pscav_i386_stack(void)
 464 {
 465     long i;
 466
 467     for (i = 0; i < num_valid_stack_locations; i++)
 468         pscav(valid_stack_locations[i], 1, 0);
 469
 470     for (i = 0; i < num_valid_stack_ra_locations; i++) {
 471         lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
 472         pscav(&code_obj, 1, 0);
 473         if (pointer_filter_verbose) {
 474             fprintf(stderr,"*C moved RA %p to %p; for code object %p to %p\n",
 475                     (void *)*valid_stack_ra_locations[i],
 476                     (void *)(*valid_stack_ra_locations[i]) -
 477                     ((void *)valid_stack_ra_code_objects[i] -
 478                      (void *)code_obj),
 479                     valid_stack_ra_code_objects[i], (void *)code_obj);
 480         }
 481         *valid_stack_ra_locations[i] =
 482             ((long)(*valid_stack_ra_locations[i])
 483              - ((long)valid_stack_ra_code_objects[i] - (long)code_obj));
 484     }
 485 }
 486 #endif
 487 #endif
 488
 489 \f
 490 static void
 491 pscav_later(lispobj *where, long count)
 492 {
 493     struct later *new;
 494
 495     if (count > LATERMAXCOUNT) {
 496         while (count > LATERMAXCOUNT) {
 497             pscav_later(where, LATERMAXCOUNT);
 498             count -= LATERMAXCOUNT;
 499             where += LATERMAXCOUNT;
 500         }
 501     }
 502     else {
 503         if (later_blocks == NULL || later_count == LATERBLOCKSIZE ||
 504             (later_count == LATERBLOCKSIZE-1 && count > 1)) {
 505             new  = (struct later *)malloc(sizeof(struct later));
 506             new->next = later_blocks;
 507             if (later_blocks && later_count < LATERBLOCKSIZE)
 508                 later_blocks->u[later_count].ptr = NULL;
 509             later_blocks = new;
 510             later_count = 0;
 511         }
 512
 513         if (count != 1)
 514             later_blocks->u[later_count++].count = count;
 515         later_blocks->u[later_count++].ptr = where;
 516     }
 517 }
 518
 519 static lispobj
 520 ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 521 {
 522     long nwords;
 523     lispobj result, *new, *old;
 524
 525     nwords = CEILING(1 + HeaderValue(header), 2);
 526
 527     /* Allocate it */
 528     old = (lispobj *)native_pointer(thing);
 529     new = newspace_alloc(nwords,constant);
 530
 531     /* Copy it. */
 532     bcopy(old, new, nwords * sizeof(lispobj));
 533
 534     /* Deposit forwarding pointer. */
 535     result = make_lispobj(new, lowtag_of(thing));
 536     *old = result;
 537
 538     /* Scavenge it. */
 539     pscav(new, nwords, constant);
 540
 541     return result;
 542 }
 543
 544 /* We need to look at the layout to see whether it is a pure structure
 545  * class, and only then can we transport as constant. If it is pure,
 546  * we can ALWAYS transport as a constant. */
 547 static lispobj
 548 ptrans_instance(lispobj thing, lispobj header, boolean /* ignored */ constant)
 549 {
 550     lispobj layout = ((struct instance *)native_pointer(thing))->slots[0];
 551     lispobj pure = ((struct instance *)native_pointer(layout))->slots[15];
 552
 553     switch (pure) {
 554     case T:
 555         return (ptrans_boxed(thing, header, 1));
 556     case NIL:
 557         return (ptrans_boxed(thing, header, 0));
 558     case 0:
 559         {
 560             /* Substructure: special case for the COMPACT-INFO-ENVs,
 561              * where the instance may have a point to the dynamic
 562              * space placed into it (e.g. the cache-name slot), but
 563              * the lists and arrays at the time of a purify can be
 564              * moved to the RO space. */
 565             long nwords;
 566             lispobj result, *new, *old;
 567
 568             nwords = CEILING(1 + HeaderValue(header), 2);
 569
 570             /* Allocate it */
 571             old = (lispobj *)native_pointer(thing);
 572             new = newspace_alloc(nwords, 0); /*  inconstant */
 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             /* Scavenge it. */
 582             pscav(new, nwords, 1);
 583
 584             return result;
 585         }
 586     default:
 587         gc_abort();
 588         return NIL; /* dummy value: return something ... */
 589     }
 590 }
 591
 592 static lispobj
 593 ptrans_fdefn(lispobj thing, lispobj header)
 594 {
 595     long nwords;
 596     lispobj result, *new, *old, oldfn;
 597     struct fdefn *fdefn;
 598
 599     nwords = CEILING(1 + HeaderValue(header), 2);
 600
 601     /* Allocate it */
 602     old = (lispobj *)native_pointer(thing);
 603     new = newspace_alloc(nwords, 0);    /* inconstant */
 604
 605     /* Copy it. */
 606     bcopy(old, new, nwords * sizeof(lispobj));
 607
 608     /* Deposit forwarding pointer. */
 609     result = make_lispobj(new, lowtag_of(thing));
 610     *old = result;
 611
 612     /* Scavenge the function. */
 613     fdefn = (struct fdefn *)new;
 614     oldfn = fdefn->fun;
 615     pscav(&fdefn->fun, 1, 0);
 616     if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
 617         fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 618
 619     return result;
 620 }
 621
 622 static lispobj
 623 ptrans_unboxed(lispobj thing, lispobj header)
 624 {
 625     long nwords;
 626     lispobj result, *new, *old;
 627
 628     nwords = CEILING(1 + HeaderValue(header), 2);
 629
 630     /* Allocate it */
 631     old = (lispobj *)native_pointer(thing);
 632     new = newspace_alloc(nwords,1);     /* always constant */
 633
 634     /* copy it. */
 635     bcopy(old, new, nwords * sizeof(lispobj));
 636
 637     /* Deposit forwarding pointer. */
 638     result = make_lispobj(new , lowtag_of(thing));
 639     *old = result;
 640
 641     return result;
 642 }
 643
 644 static lispobj
 645 ptrans_vector(lispobj thing, long bits, long extra,
 646               boolean boxed, boolean constant)
 647 {
 648     struct vector *vector;
 649     long nwords;
 650     lispobj result, *new;
 651     long length;
 652
 653     vector = (struct vector *)native_pointer(thing);
 654     length = fixnum_value(vector->length)+extra;
 655     // Argh, handle simple-vector-nil separately.
 656     if (bits == 0) {
 657       nwords = 2;
 658     } else {
 659       nwords = CEILING(NWORDS(length, bits) + 2, 2);
 660     }
 661
 662     new=newspace_alloc(nwords, (constant || !boxed));
 663     bcopy(vector, new, nwords * sizeof(lispobj));
 664
 665     result = make_lispobj(new, lowtag_of(thing));
 666     vector->header = result;
 667
 668     if (boxed)
 669         pscav(new, nwords, constant);
 670
 671     return result;
 672 }
 673
 674 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 675 static void
 676 apply_code_fixups_during_purify(struct code *old_code, struct code *new_code)
 677 {
 678     long nheader_words, ncode_words, nwords;
 679     void  *constants_start_addr, *constants_end_addr;
 680     void  *code_start_addr, *code_end_addr;
 681     lispobj fixups = NIL;
 682     unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
 683     struct vector *fixups_vector;
 684
 685     ncode_words = fixnum_value(new_code->code_size);
 686     nheader_words = HeaderValue(*(lispobj *)new_code);
 687     nwords = ncode_words + nheader_words;
 688
 689     constants_start_addr = (void *)new_code + 5 * N_WORD_BYTES;
 690     constants_end_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
 691     code_start_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
 692     code_end_addr = (void *)new_code + nwords*N_WORD_BYTES;
 693
 694     /* The first constant should be a pointer to the fixups for this
 695      * code objects. Check. */
 696     fixups = new_code->constants[0];
 697
 698     /* It will be 0 or the unbound-marker if there are no fixups, and
 699      * will be an other-pointer to a vector if it is valid. */
 700     if ((fixups==0) ||
 701         (fixups==UNBOUND_MARKER_WIDETAG) ||
 702         !is_lisp_pointer(fixups)) {
 703 #ifdef LISP_FEATURE_GENCGC
 704         /* Check for a possible errors. */
 705         sniff_code_object(new_code,displacement);
 706 #endif
 707         return;
 708     }
 709
 710     fixups_vector = (struct vector *)native_pointer(fixups);
 711
 712     /* Could be pointing to a forwarding pointer. */
 713     if (is_lisp_pointer(fixups) && (dynamic_pointer_p(fixups))
 714         && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
 715         /* If so then follow it. */
 716         fixups_vector =
 717             (struct vector *)native_pointer(*(lispobj *)fixups_vector);
 718     }
 719
 720     if (widetag_of(fixups_vector->header) == SIMPLE_ARRAY_WORD_WIDETAG) {
 721         /* We got the fixups for the code block. Now work through the
 722          * vector, and apply a fixup at each address. */
 723         long length = fixnum_value(fixups_vector->length);
 724         long i;
 725         for (i=0; i<length; i++) {
 726             unsigned offset = fixups_vector->data[i];
 727             /* Now check the current value of offset. */
 728             unsigned old_value =
 729                 *(unsigned *)((unsigned)code_start_addr + offset);
 730
 731             /* If it's within the old_code object then it must be an
 732              * absolute fixup (relative ones are not saved) */
 733             if ((old_value>=(unsigned)old_code)
 734                 && (old_value<((unsigned)old_code + nwords * N_WORD_BYTES)))
 735                 /* So add the dispacement. */
 736                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 737                     + displacement;
 738             else
 739                 /* It is outside the old code object so it must be a relative
 740                  * fixup (absolute fixups are not saved). So subtract the
 741                  * displacement. */
 742                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 743                     - displacement;
 744         }
 745     }
 746
 747     /* No longer need the fixups. */
 748     new_code->constants[0] = 0;
 749
 750 #ifdef LISP_FEATURE_GENCGC
 751     /* Check for possible errors. */
 752     sniff_code_object(new_code,displacement);
 753 #endif
 754 }
 755 #endif
 756
 757 static lispobj
 758 ptrans_code(lispobj thing)
 759 {
 760     struct code *code, *new;
 761     long nwords;
 762     lispobj func, result;
 763
 764     code = (struct code *)native_pointer(thing);
 765     nwords = CEILING(HeaderValue(code->header) + fixnum_value(code->code_size),
 766                      2);
 767
 768     new = (struct code *)newspace_alloc(nwords,1); /* constant */
 769
 770     bcopy(code, new, nwords * sizeof(lispobj));
 771
 772 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 773     apply_code_fixups_during_purify(code,new);
 774 #endif
 775
 776     result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 777
 778     /* Stick in a forwarding pointer for the code object. */
 779     *(lispobj *)code = result;
 780
 781     /* Put in forwarding pointers for all the functions. */
 782     for (func = code->entry_points;
 783          func != NIL;
 784          func = ((struct simple_fun *)native_pointer(func))->next) {
 785
 786         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 787
 788         *(lispobj *)native_pointer(func) = result + (func - thing);
 789     }
 790
 791     /* Arrange to scavenge the debug info later. */
 792     pscav_later(&new->debug_info, 1);
 793
 794     /* FIXME: why would this be a fixnum? */
 795     /* "why" is a hard word, but apparently for compiled functions the
 796        trace_table_offset contains the length of the instructions, as
 797        a fixnum.  See CODE-INST-AREA-LENGTH in
 798        src/compiler/target-disassem.lisp.  -- CSR, 2004-01-08 */
 799     if (!(fixnump(new->trace_table_offset)))
 800 #if 0
 801         pscav(&new->trace_table_offset, 1, 0);
 802 #else
 803         new->trace_table_offset = NIL; /* limit lifetime */
 804 #endif
 805
 806     /* Scavenge the constants. */
 807     pscav(new->constants, HeaderValue(new->header)-5, 1);
 808
 809     /* Scavenge all the functions. */
 810     pscav(&new->entry_points, 1, 1);
 811     for (func = new->entry_points;
 812          func != NIL;
 813          func = ((struct simple_fun *)native_pointer(func))->next) {
 814         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 815         gc_assert(!dynamic_pointer_p(func));
 816
 817 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 818         /* Temporarily convert the self pointer to a real function pointer. */
 819         ((struct simple_fun *)native_pointer(func))->self
 820             -= FUN_RAW_ADDR_OFFSET;
 821 #endif
 822         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 823 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
 824         ((struct simple_fun *)native_pointer(func))->self
 825             += FUN_RAW_ADDR_OFFSET;
 826 #endif
 827         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
 828     }
 829
 830     return result;
 831 }
 832
 833 static lispobj
 834 ptrans_func(lispobj thing, lispobj header)
 835 {
 836     long nwords;
 837     lispobj code, *new, *old, result;
 838     struct simple_fun *function;
 839
 840     /* Thing can either be a function header, a closure function
 841      * header, a closure, or a funcallable-instance. If it's a closure
 842      * or a funcallable-instance, we do the same as ptrans_boxed.
 843      * Otherwise we have to do something strange, 'cause it is buried
 844      * inside a code object. */
 845
 846     if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG) {
 847
 848         /* We can only end up here if the code object has not been
 849          * scavenged, because if it had been scavenged, forwarding pointers
 850          * would have been left behind for all the entry points. */
 851
 852         function = (struct simple_fun *)native_pointer(thing);
 853         code =
 854             make_lispobj
 855             ((native_pointer(thing) -
 856               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 857
 858         /* This will cause the function's header to be replaced with a
 859          * forwarding pointer. */
 860
 861         ptrans_code(code);
 862
 863         /* So we can just return that. */
 864         return function->header;
 865     }
 866     else {
 867         /* It's some kind of closure-like thing. */
 868         nwords = CEILING(1 + HeaderValue(header), 2);
 869         old = (lispobj *)native_pointer(thing);
 870
 871         /* Allocate the new one.  FINs *must* not go in read_only
 872          * space.  Closures can; they never change */
 873
 874         new = newspace_alloc
 875             (nwords,(widetag_of(header)!=FUNCALLABLE_INSTANCE_HEADER_WIDETAG));
 876
 877         /* Copy it. */
 878         bcopy(old, new, nwords * sizeof(lispobj));
 879
 880         /* Deposit forwarding pointer. */
 881         result = make_lispobj(new, lowtag_of(thing));
 882         *old = result;
 883
 884         /* Scavenge it. */
 885         pscav(new, nwords, 0);
 886
 887         return result;
 888     }
 889 }
 890
 891 static lispobj
 892 ptrans_returnpc(lispobj thing, lispobj header)
 893 {
 894     lispobj code, new;
 895
 896     /* Find the corresponding code object. */
 897     code = thing - HeaderValue(header)*sizeof(lispobj);
 898
 899     /* Make sure it's been transported. */
 900     new = *(lispobj *)native_pointer(code);
 901     if (!forwarding_pointer_p(new))
 902         new = ptrans_code(code);
 903
 904     /* Maintain the offset: */
 905     return new + (thing - code);
 906 }
 907
 908 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 909
 910 static lispobj
 911 ptrans_list(lispobj thing, boolean constant)
 912 {
 913     struct cons *old, *new, *orig;
 914     long length;
 915
 916     orig = (struct cons *) newspace_alloc(0,constant);
 917     length = 0;
 918
 919     do {
 920         /* Allocate a new cons cell. */
 921         old = (struct cons *)native_pointer(thing);
 922         new = (struct cons *) newspace_alloc(WORDS_PER_CONS,constant);
 923
 924         /* Copy the cons cell and keep a pointer to the cdr. */
 925         new->car = old->car;
 926         thing = new->cdr = old->cdr;
 927
 928         /* Set up the forwarding pointer. */
 929         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 930
 931         /* And count this cell. */
 932         length++;
 933     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 934              dynamic_pointer_p(thing) &&
 935              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 936
 937     /* Scavenge the list we just copied. */
 938     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 939
 940     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 941 }
 942
 943 static lispobj
 944 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 945 {
 946     switch (widetag_of(header)) {
 947         /* FIXME: this needs a reindent */
 948       case BIGNUM_WIDETAG:
 949       case SINGLE_FLOAT_WIDETAG:
 950       case DOUBLE_FLOAT_WIDETAG:
 951 #ifdef LONG_FLOAT_WIDETAG
 952       case LONG_FLOAT_WIDETAG:
 953 #endif
 954 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 955       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 956 #endif
 957 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 958       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 959 #endif
 960 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 961       case COMPLEX_LONG_FLOAT_WIDETAG:
 962 #endif
 963       case SAP_WIDETAG:
 964           return ptrans_unboxed(thing, header);
 965
 966       case RATIO_WIDETAG:
 967       case COMPLEX_WIDETAG:
 968       case SIMPLE_ARRAY_WIDETAG:
 969       case COMPLEX_BASE_STRING_WIDETAG:
 970 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
 971     case COMPLEX_CHARACTER_STRING_WIDETAG:
 972 #endif
 973       case COMPLEX_BIT_VECTOR_WIDETAG:
 974       case COMPLEX_VECTOR_NIL_WIDETAG:
 975       case COMPLEX_VECTOR_WIDETAG:
 976       case COMPLEX_ARRAY_WIDETAG:
 977         return ptrans_boxed(thing, header, constant);
 978
 979       case VALUE_CELL_HEADER_WIDETAG:
 980       case WEAK_POINTER_WIDETAG:
 981         return ptrans_boxed(thing, header, 0);
 982
 983       case SYMBOL_HEADER_WIDETAG:
 984         return ptrans_boxed(thing, header, 0);
 985
 986       case SIMPLE_ARRAY_NIL_WIDETAG:
 987         return ptrans_vector(thing, 0, 0, 0, constant);
 988
 989       case SIMPLE_BASE_STRING_WIDETAG:
 990         return ptrans_vector(thing, 8, 1, 0, constant);
 991
 992 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
 993     case SIMPLE_CHARACTER_STRING_WIDETAG:
 994         return ptrans_vector(thing, 32, 1, 0, constant);
 995 #endif
 996
 997       case SIMPLE_BIT_VECTOR_WIDETAG:
 998         return ptrans_vector(thing, 1, 0, 0, constant);
 999
1000       case SIMPLE_VECTOR_WIDETAG:
1001         return ptrans_vector(thing, N_WORD_BITS, 0, 1, constant);
1002
1003       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1004         return ptrans_vector(thing, 2, 0, 0, constant);
1005
1006       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1007         return ptrans_vector(thing, 4, 0, 0, constant);
1008
1009       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1010 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1011       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1012       case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
1013 #endif
1014         return ptrans_vector(thing, 8, 0, 0, constant);
1015
1016       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1017 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1018       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1019       case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
1020 #endif
1021         return ptrans_vector(thing, 16, 0, 0, constant);
1022
1023       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1024 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1025       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1026       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
1027 #endif
1028 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1029       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1030       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
1031 #endif
1032         return ptrans_vector(thing, 32, 0, 0, constant);
1033
1034 #if N_WORD_BITS == 64
1035 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
1036       case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
1037 #endif
1038 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
1039       case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
1040 #endif
1041 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
1042       case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
1043 #endif
1044 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
1045       case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
1046 #endif
1047 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
1048       case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
1049 #endif
1050         return ptrans_vector(thing, 64, 0, 0, constant);
1051 #endif
1052
1053       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1054         return ptrans_vector(thing, 32, 0, 0, constant);
1055
1056       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1057         return ptrans_vector(thing, 64, 0, 0, constant);
1058
1059 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1060       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1061 #ifdef LISP_FEATURE_X86
1062         return ptrans_vector(thing, 96, 0, 0, constant);
1063 #endif
1064 #ifdef LISP_FEATURE_SPARC
1065         return ptrans_vector(thing, 128, 0, 0, constant);
1066 #endif
1067 #endif
1068
1069 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1070       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1071         return ptrans_vector(thing, 64, 0, 0, constant);
1072 #endif
1073
1074 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1075       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1076         return ptrans_vector(thing, 128, 0, 0, constant);
1077 #endif
1078
1079 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1080       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1081 #ifdef LISP_FEATURE_X86
1082         return ptrans_vector(thing, 192, 0, 0, constant);
1083 #endif
1084 #ifdef LISP_FEATURE_SPARC
1085         return ptrans_vector(thing, 256, 0, 0, constant);
1086 #endif
1087 #endif
1088
1089       case CODE_HEADER_WIDETAG:
1090         return ptrans_code(thing);
1091
1092       case RETURN_PC_HEADER_WIDETAG:
1093         return ptrans_returnpc(thing, header);
1094
1095       case FDEFN_WIDETAG:
1096         return ptrans_fdefn(thing, header);
1097
1098       default:
1099         fprintf(stderr, "Invalid widetag: %d\n", widetag_of(header));
1100         /* Should only come across other pointers to the above stuff. */
1101         gc_abort();
1102         return NIL;
1103     }
1104 }
1105
1106 static long
1107 pscav_fdefn(struct fdefn *fdefn)
1108 {
1109     boolean fix_func;
1110
1111     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
1112     pscav(&fdefn->name, 1, 1);
1113     pscav(&fdefn->fun, 1, 0);
1114     if (fix_func)
1115         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
1116     return sizeof(struct fdefn) / sizeof(lispobj);
1117 }
1118
1119 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
1120 /* now putting code objects in static space */
1121 static long
1122 pscav_code(struct code*code)
1123 {
1124     long nwords;
1125     lispobj func;
1126     nwords = CEILING(HeaderValue(code->header) + fixnum_value(code->code_size),
1127                      2);
1128
1129     /* Arrange to scavenge the debug info later. */
1130     pscav_later(&code->debug_info, 1);
1131
1132     /* Scavenge the constants. */
1133     pscav(code->constants, HeaderValue(code->header)-5, 1);
1134
1135     /* Scavenge all the functions. */
1136     pscav(&code->entry_points, 1, 1);
1137     for (func = code->entry_points;
1138          func != NIL;
1139          func = ((struct simple_fun *)native_pointer(func))->next) {
1140         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
1141         gc_assert(!dynamic_pointer_p(func));
1142
1143 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
1144         /* Temporarily convert the self pointer to a real function
1145          * pointer. */
1146         ((struct simple_fun *)native_pointer(func))->self
1147             -= FUN_RAW_ADDR_OFFSET;
1148 #endif
1149         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
1150 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
1151         ((struct simple_fun *)native_pointer(func))->self
1152             += FUN_RAW_ADDR_OFFSET;
1153 #endif
1154         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
1155     }
1156
1157     return CEILING(nwords,2);
1158 }
1159 #endif
1160
1161 static lispobj *
1162 pscav(lispobj *addr, long nwords, boolean constant)
1163 {
1164     lispobj thing, *thingp, header;
1165     long count = 0; /* (0 = dummy init value to stop GCC warning) */
1166     struct vector *vector;
1167
1168     while (nwords > 0) {
1169         thing = *addr;
1170         if (is_lisp_pointer(thing)) {
1171             /* It's a pointer. Is it something we might have to move? */
1172             if (dynamic_pointer_p(thing)) {
1173                 /* Maybe. Have we already moved it? */
1174                 thingp = (lispobj *)native_pointer(thing);
1175                 header = *thingp;
1176                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
1177                     /* Yep, so just copy the forwarding pointer. */
1178                     thing = header;
1179                 else {
1180                     /* Nope, copy the object. */
1181                     switch (lowtag_of(thing)) {
1182                       case FUN_POINTER_LOWTAG:
1183                         thing = ptrans_func(thing, header);
1184                         break;
1185
1186                       case LIST_POINTER_LOWTAG:
1187                         thing = ptrans_list(thing, constant);
1188                         break;
1189
1190                       case INSTANCE_POINTER_LOWTAG:
1191                         thing = ptrans_instance(thing, header, constant);
1192                         break;
1193
1194                       case OTHER_POINTER_LOWTAG:
1195                         thing = ptrans_otherptr(thing, header, constant);
1196                         break;
1197
1198                       default:
1199                         /* It was a pointer, but not one of them? */
1200                         gc_abort();
1201                     }
1202                 }
1203                 *addr = thing;
1204             }
1205             count = 1;
1206         }
1207 #if N_WORD_BITS == 64
1208         else if (widetag_of(thing) == SINGLE_FLOAT_WIDETAG) {
1209             count = 1;
1210         }
1211 #endif
1212         else if (thing & FIXNUM_TAG_MASK) {
1213             /* It's an other immediate. Maybe the header for an unboxed */
1214             /* object. */
1215             switch (widetag_of(thing)) {
1216               case BIGNUM_WIDETAG:
1217               case SINGLE_FLOAT_WIDETAG:
1218               case DOUBLE_FLOAT_WIDETAG:
1219 #ifdef LONG_FLOAT_WIDETAG
1220               case LONG_FLOAT_WIDETAG:
1221 #endif
1222               case SAP_WIDETAG:
1223                 /* It's an unboxed simple object. */
1224                 count = CEILING(HeaderValue(thing)+1, 2);
1225                 break;
1226
1227               case SIMPLE_VECTOR_WIDETAG:
1228                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
1229                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
1230                         SIMPLE_VECTOR_WIDETAG;
1231                   }
1232                 count = 2;
1233                 break;
1234
1235               case SIMPLE_ARRAY_NIL_WIDETAG:
1236                 count = 2;
1237                 break;
1238
1239               case SIMPLE_BASE_STRING_WIDETAG:
1240                 vector = (struct vector *)addr;
1241                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,8)+2,2);
1242                 break;
1243
1244 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
1245             case SIMPLE_CHARACTER_STRING_WIDETAG:
1246                 vector = (struct vector *)addr;
1247                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,32)+2,2);
1248                 break;
1249 #endif
1250
1251               case SIMPLE_BIT_VECTOR_WIDETAG:
1252                 vector = (struct vector *)addr;
1253                 count = CEILING(NWORDS(fixnum_value(vector->length),1)+2,2);
1254                 break;
1255
1256               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1257                 vector = (struct vector *)addr;
1258                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
1259                 break;
1260
1261               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1262                 vector = (struct vector *)addr;
1263                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
1264                 break;
1265
1266               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1267 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1268               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1269               case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
1270 #endif
1271                 vector = (struct vector *)addr;
1272                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
1273                 break;
1274
1275               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1276 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1277               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1278               case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
1279 #endif
1280                 vector = (struct vector *)addr;
1281                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
1282                 break;
1283
1284               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1285 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1286               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1287               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
1288 #endif
1289 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1290               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1291               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
1292 #endif
1293                 vector = (struct vector *)addr;
1294                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
1295                 break;
1296
1297 #if N_WORD_BITS == 64
1298               case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
1299 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
1300               case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
1301               case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
1302 #endif
1303 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
1304               case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
1305               case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
1306 #endif
1307                 vector = (struct vector *)addr;
1308                 count = CEILING(NWORDS(fixnum_value(vector->length),64)+2,2);
1309                 break;
1310 #endif
1311
1312               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1313                 vector = (struct vector *)addr;
1314                 count = CEILING(NWORDS(fixnum_value(vector->length), 32) + 2,
1315                                 2);
1316                 break;
1317
1318               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1319 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1320               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1321 #endif
1322                 vector = (struct vector *)addr;
1323                 count = CEILING(NWORDS(fixnum_value(vector->length), 64) + 2,
1324                                 2);
1325                 break;
1326
1327 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1328               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1329                 vector = (struct vector *)addr;
1330 #ifdef LISP_FEATURE_X86
1331                 count = fixnum_value(vector->length)*3+2;
1332 #endif
1333 #ifdef LISP_FEATURE_SPARC
1334                 count = fixnum_value(vector->length)*4+2;
1335 #endif
1336                 break;
1337 #endif
1338
1339 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1340               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1341                 vector = (struct vector *)addr;
1342                 count = CEILING(NWORDS(fixnum_value(vector->length), 128) + 2,
1343                                 2);
1344                 break;
1345 #endif
1346
1347 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1348               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1349                 vector = (struct vector *)addr;
1350 #ifdef LISP_FEATURE_X86
1351                 count = fixnum_value(vector->length)*6+2;
1352 #endif
1353 #ifdef LISP_FEATURE_SPARC
1354                 count = fixnum_value(vector->length)*8+2;
1355 #endif
1356                 break;
1357 #endif
1358
1359               case CODE_HEADER_WIDETAG:
1360 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
1361                 gc_abort(); /* no code headers in static space */
1362 #else
1363                 count = pscav_code((struct code*)addr);
1364 #endif
1365                 break;
1366
1367               case SIMPLE_FUN_HEADER_WIDETAG:
1368               case RETURN_PC_HEADER_WIDETAG:
1369                 /* We should never hit any of these, 'cause they occur
1370                  * buried in the middle of code objects. */
1371                 gc_abort();
1372                 break;
1373
1374 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
1375               case CLOSURE_HEADER_WIDETAG:
1376               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
1377                 /* The function self pointer needs special care on the
1378                  * x86 because it is the real entry point. */
1379                 {
1380                   lispobj fun = ((struct closure *)addr)->fun
1381                     - FUN_RAW_ADDR_OFFSET;
1382                   pscav(&fun, 1, constant);
1383                   ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
1384                 }
1385                 count = 2;
1386                 break;
1387 #endif
1388
1389               case WEAK_POINTER_WIDETAG:
1390                 /* Weak pointers get preserved during purify, 'cause I
1391                  * don't feel like figuring out how to break them. */
1392                 pscav(addr+1, 2, constant);
1393                 count = 4;
1394                 break;
1395
1396               case FDEFN_WIDETAG:
1397                 /* We have to handle fdefn objects specially, so we
1398                  * can fix up the raw function address. */
1399                 count = pscav_fdefn((struct fdefn *)addr);
1400                 break;
1401
1402               case INSTANCE_HEADER_WIDETAG:
1403                 {
1404                     struct instance *instance = (struct instance *) addr;
1405                     struct layout *layout
1406                         = (struct layout *) native_pointer(instance->slots[0]);
1407                     long nuntagged = fixnum_value(layout->n_untagged_slots);
1408                     long nslots = HeaderValue(*addr);
1409                     pscav(addr + 1, nslots - nuntagged, constant);
1410                     count = CEILING(1 + nslots, 2);
1411                 }
1412                 break;
1413
1414               default:
1415                 count = 1;
1416                 break;
1417             }
1418         }
1419         else {
1420             /* It's a fixnum. */
1421             count = 1;
1422         }
1423
1424         addr += count;
1425         nwords -= count;
1426     }
1427
1428     return addr;
1429 }
1430
1431 int
1432 purify(lispobj static_roots, lispobj read_only_roots)
1433 {
1434     lispobj *clean;
1435     long count, i;
1436     struct later *laters, *next;
1437     struct thread *thread;
1438
1439     if(all_threads->next) {
1440         /* FIXME: there should be _some_ sensible error reporting
1441          * convention.  See following comment too */
1442         fprintf(stderr,"Can't purify when more than one thread exists\n");
1443         fflush(stderr);
1444         return 0;
1445     }
1446
1447 #ifdef PRINTNOISE
1448     printf("[doing purification:");
1449     fflush(stdout);
1450 #endif
1451 #ifdef LISP_FEATURE_GENCGC
1452     gc_alloc_update_all_page_tables();
1453 #endif
1454     for_each_thread(thread)
1455         if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)) != 0) {
1456         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
1457          * its error simply by a. printing a string b. to stdout instead
1458          * of stderr. */
1459         printf(" Ack! Can't purify interrupt contexts. ");
1460         fflush(stdout);
1461         return 0;
1462     }
1463
1464 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
1465     dynamic_space_free_pointer =
1466       (lispobj*)SymbolValue(ALLOCATION_POINTER,0);
1467 #endif
1468
1469     read_only_end = read_only_free =
1470         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
1471     static_end = static_free =
1472         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
1473
1474 #ifdef PRINTNOISE
1475     printf(" roots");
1476     fflush(stdout);
1477 #endif
1478
1479 #if defined(LISP_FEATURE_GENCGC) && (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
1480     /* note this expects only one thread to be active.  We'd have to
1481      * stop all the others in the same way as GC does if we wanted
1482      * PURIFY to work when >1 thread exists */
1483     setup_i386_stack_scav(((&static_roots)-2),
1484                           ((void *)all_threads->control_stack_end));
1485 #endif
1486
1487     pscav(&static_roots, 1, 0);
1488     pscav(&read_only_roots, 1, 1);
1489
1490 #ifdef PRINTNOISE
1491     printf(" handlers");
1492     fflush(stdout);
1493 #endif
1494     pscav((lispobj *) interrupt_handlers,
1495           sizeof(interrupt_handlers) / sizeof(lispobj),
1496           0);
1497
1498 #ifdef PRINTNOISE
1499     printf(" stack");
1500     fflush(stdout);
1501 #endif
1502 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
1503     pscav((lispobj *)all_threads->control_stack_start,
1504           current_control_stack_pointer -
1505           all_threads->control_stack_start,
1506           0);
1507 #else
1508 #ifdef LISP_FEATURE_GENCGC
1509     pscav_i386_stack();
1510 #endif
1511 #endif
1512
1513 #ifdef PRINTNOISE
1514     printf(" bindings");
1515     fflush(stdout);
1516 #endif
1517 #if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
1518     pscav( (lispobj *)all_threads->binding_stack_start,
1519           (lispobj *)current_binding_stack_pointer -
1520            all_threads->binding_stack_start,
1521           0);
1522 #else
1523     for_each_thread(thread) {
1524         pscav( (lispobj *)thread->binding_stack_start,
1525                (lispobj *)SymbolValue(BINDING_STACK_POINTER,thread) -
1526                (lispobj *)thread->binding_stack_start,
1527           0);
1528         pscav( (lispobj *) (thread+1),
1529                fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
1530                (sizeof (struct thread))/(sizeof (lispobj)),
1531           0);
1532     }
1533
1534
1535 #endif
1536
1537     /* The original CMU CL code had scavenge-read-only-space code
1538      * controlled by the Lisp-level variable
1539      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
1540      * wasn't documented under what circumstances it was useful or
1541      * safe to turn it on, so it's been turned off in SBCL. If you
1542      * want/need this functionality, and can test and document it,
1543      * please submit a patch. */
1544 #if 0
1545     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
1546         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
1547       unsigned  read_only_space_size =
1548           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
1549           (lispobj *)READ_ONLY_SPACE_START;
1550       fprintf(stderr,
1551               "scavenging read only space: %d bytes\n",
1552               read_only_space_size * sizeof(lispobj));
1553       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
1554     }
1555 #endif
1556
1557 #ifdef PRINTNOISE
1558     printf(" static");
1559     fflush(stdout);
1560 #endif
1561     clean = (lispobj *)STATIC_SPACE_START;
1562     do {
1563         while (clean != static_free)
1564             clean = pscav(clean, static_free - clean, 0);
1565         laters = later_blocks;
1566         count = later_count;
1567         later_blocks = NULL;
1568         later_count = 0;
1569         while (laters != NULL) {
1570             for (i = 0; i < count; i++) {
1571                 if (laters->u[i].count == 0) {
1572                     ;
1573                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1574                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1575                     i++;
1576                 } else {
1577                     pscav(laters->u[i].ptr, 1, 1);
1578                 }
1579             }
1580             next = laters->next;
1581             free(laters);
1582             laters = next;
1583             count = LATERBLOCKSIZE;
1584         }
1585     } while (clean != static_free || later_blocks != NULL);
1586
1587 #ifdef PRINTNOISE
1588     printf(" cleanup");
1589     fflush(stdout);
1590 #endif
1591
1592     os_zero((os_vm_address_t) current_dynamic_space,
1593             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
1594
1595     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
1596      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
1597 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
1598     os_zero((os_vm_address_t) current_control_stack_pointer,
1599             (os_vm_size_t)
1600             ((all_threads->control_stack_end -
1601               current_control_stack_pointer) * sizeof(lispobj)));
1602 #endif
1603
1604     /* It helps to update the heap free pointers so that free_heap can
1605      * verify after it's done. */
1606     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free,0);
1607     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free,0);
1608
1609 #if !defined(ALLOCATION_POINTER)
1610     dynamic_space_free_pointer = current_dynamic_space;
1611     set_auto_gc_trigger(bytes_consed_between_gcs);
1612 #else
1613 #if defined LISP_FEATURE_GENCGC
1614     gc_free_heap();
1615 #else
1616 #error unsupported case /* in CMU CL, was "ibmrt using GC" */
1617 #endif
1618 #endif
1619
1620     /* Blast away instruction cache */
1621     os_flush_icache((os_vm_address_t)READ_ONLY_SPACE_START, READ_ONLY_SPACE_SIZE);
1622     os_flush_icache((os_vm_address_t)STATIC_SPACE_START, STATIC_SPACE_SIZE);
1623
1624 #ifdef PRINTNOISE
1625     printf(" done]\n");
1626     fflush(stdout);
1627 #endif
1628     return 0;
1629 }