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
  37 #define PRINTNOISE
  38
  39 #if defined(LISP_FEATURE_GENCGC)
  40 /* this is another artifact of the poor integration between gencgc and
  41  * the rest of the runtime: on cheney gc there is a global
  42  * dynamic_space_free_pointer which is valid whenever foreign function
  43  * call is active, but in gencgc there's no such variable and we have
  44  * to keep our own
  45  */
  46 static lispobj *dynamic_space_free_pointer;
  47 #endif
  48 extern unsigned long bytes_consed_between_gcs;
  49
  50 #define gc_abort() \
  51   lose("GC invariant lost, file \"%s\", line %d", __FILE__, __LINE__)
  52
  53 #if 1
  54 #define gc_assert(ex) do { \
  55         if (!(ex)) gc_abort(); \
  56 } while (0)
  57 #else
  58 #define gc_assert(ex)
  59 #endif
  60
  61 \f
  62 /* These hold the original end of the read_only and static spaces so
  63  * we can tell what are forwarding pointers. */
  64
  65 static lispobj *read_only_end, *static_end;
  66
  67 static lispobj *read_only_free, *static_free;
  68
  69 static lispobj *pscav(lispobj *addr, int nwords, boolean constant);
  70
  71 #define LATERBLOCKSIZE 1020
  72 #define LATERMAXCOUNT 10
  73
  74 static struct
  75 later {
  76     struct later *next;
  77     union {
  78         lispobj *ptr;
  79         int count;
  80     } u[LATERBLOCKSIZE];
  81 } *later_blocks = NULL;
  82 static int later_count = 0;
  83
  84 /* FIXME: Shouldn't this be defined in sbcl.h?  See also notes in
  85  * cheneygc.c */
  86
  87 #ifdef sparc
  88 #define FUN_RAW_ADDR_OFFSET 0
  89 #else
  90 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
  91 #endif
  92 \f
  93 static boolean
  94 forwarding_pointer_p(lispobj obj)
  95 {
  96     lispobj *ptr = native_pointer(obj);
  97
  98     return ((static_end <= ptr && ptr <= static_free) ||
  99             (read_only_end <= ptr && ptr <= read_only_free));
 100 }
 101
 102 static boolean
 103 dynamic_pointer_p(lispobj ptr)
 104 {
 105 #ifndef LISP_FEATURE_GENCGC
 106     return (ptr >= (lispobj)current_dynamic_space
 107             &&
 108             ptr < (lispobj)dynamic_space_free_pointer);
 109 #else
 110     /* Be more conservative, and remember, this is a maybe. */
 111     return (ptr >= (lispobj)DYNAMIC_SPACE_START
 112             &&
 113             ptr < (lispobj)dynamic_space_free_pointer);
 114 #endif
 115 }
 116
 117 static inline lispobj *
 118 newspace_alloc(int nwords, int constantp)
 119 {
 120     lispobj *ret;
 121     nwords=CEILING(nwords,2);
 122     if(constantp) {
 123         ret=read_only_free;
 124         read_only_free+=nwords;
 125     } else {
 126         ret=static_free;
 127         static_free+=nwords;
 128     }
 129     return ret;
 130 }
 131
 132
 133 \f
 134 #ifdef LISP_FEATURE_X86
 135
 136 #ifdef LISP_FEATURE_GENCGC
 137 /*
 138  * enhanced x86/GENCGC stack scavenging by Douglas Crosher
 139  *
 140  * Scavenging the stack on the i386 is problematic due to conservative
 141  * roots and raw return addresses. Here it is handled in two passes:
 142  * the first pass runs before any objects are moved and tries to
 143  * identify valid pointers and return address on the stack, the second
 144  * pass scavenges these.
 145  */
 146
 147 static unsigned pointer_filter_verbose = 0;
 148
 149 /* FIXME: This is substantially the same code as
 150  * possibly_valid_dynamic_space_pointer in gencgc.c.  The only
 151  * relevant difference seems to be that the gencgc code also checks
 152  * for raw pointers into Code objects, whereas in purify these are
 153  * checked separately in setup_i386_stack_scav - they go onto
 154  * valid_stack_ra_locations instead of just valid_stack_locations */
 155
 156 static int
 157 valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
 158 {
 159     /* If it's not a return address then it needs to be a valid Lisp
 160      * pointer. */
 161     if (!is_lisp_pointer((lispobj)pointer))
 162         return 0;
 163
 164     /* Check that the object pointed to is consistent with the pointer
 165      * low tag. */
 166     switch (lowtag_of((lispobj)pointer)) {
 167     case FUN_POINTER_LOWTAG:
 168         /* Start_addr should be the enclosing code object, or a closure
 169          * header. */
 170         switch (widetag_of(*start_addr)) {
 171         case CODE_HEADER_WIDETAG:
 172             /* This case is probably caught above. */
 173             break;
 174         case CLOSURE_HEADER_WIDETAG:
 175         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 176             if ((int)pointer != ((int)start_addr+FUN_POINTER_LOWTAG)) {
 177                 if (pointer_filter_verbose) {
 178                     fprintf(stderr,"*Wf2: %x %x %x\n", (unsigned int) pointer,
 179                             (unsigned int) start_addr, *start_addr);
 180                 }
 181                 return 0;
 182             }
 183             break;
 184         default:
 185             if (pointer_filter_verbose) {
 186                 fprintf(stderr,"*Wf3: %x %x %x\n", (unsigned int) pointer,
 187                         (unsigned int) start_addr, *start_addr);
 188             }
 189             return 0;
 190         }
 191         break;
 192     case LIST_POINTER_LOWTAG:
 193         if ((int)pointer != ((int)start_addr+LIST_POINTER_LOWTAG)) {
 194             if (pointer_filter_verbose)
 195                 fprintf(stderr,"*Wl1: %x %x %x\n", (unsigned int) pointer,
 196                         (unsigned int) start_addr, *start_addr);
 197             return 0;
 198         }
 199         /* Is it plausible cons? */
 200         if ((is_lisp_pointer(start_addr[0])
 201             || ((start_addr[0] & 3) == 0) /* fixnum */
 202             || (widetag_of(start_addr[0]) == CHARACTER_WIDETAG)
 203             || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
 204            && (is_lisp_pointer(start_addr[1])
 205                || ((start_addr[1] & 3) == 0) /* fixnum */
 206                || (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
 207                || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
 208             break;
 209         } else {
 210             if (pointer_filter_verbose) {
 211                 fprintf(stderr,"*Wl2: %x %x %x\n", (unsigned int) pointer,
 212                         (unsigned int) start_addr, *start_addr);
 213             }
 214             return 0;
 215         }
 216     case INSTANCE_POINTER_LOWTAG:
 217         if ((int)pointer != ((int)start_addr+INSTANCE_POINTER_LOWTAG)) {
 218             if (pointer_filter_verbose) {
 219                 fprintf(stderr,"*Wi1: %x %x %x\n", (unsigned int) pointer,
 220                         (unsigned int) start_addr, *start_addr);
 221             }
 222             return 0;
 223         }
 224         if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
 225             if (pointer_filter_verbose) {
 226                 fprintf(stderr,"*Wi2: %x %x %x\n", (unsigned int) pointer,
 227                         (unsigned int) start_addr, *start_addr);
 228             }
 229             return 0;
 230         }
 231         break;
 232     case OTHER_POINTER_LOWTAG:
 233         if ((int)pointer != ((int)start_addr+OTHER_POINTER_LOWTAG)) {
 234             if (pointer_filter_verbose) {
 235                 fprintf(stderr,"*Wo1: %x %x %x\n", (unsigned int) pointer,
 236                         (unsigned int) start_addr, *start_addr);
 237             }
 238             return 0;
 239         }
 240         /* Is it plausible? Not a cons. XXX should check the headers. */
 241         if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
 242             if (pointer_filter_verbose) {
 243                 fprintf(stderr,"*Wo2: %x %x %x\n", (unsigned int) pointer,
 244                         (unsigned int) start_addr, *start_addr);
 245             }
 246             return 0;
 247         }
 248         switch (widetag_of(start_addr[0])) {
 249         case UNBOUND_MARKER_WIDETAG:
 250         case CHARACTER_WIDETAG:
 251             if (pointer_filter_verbose) {
 252                 fprintf(stderr,"*Wo3: %x %x %x\n", (unsigned int) pointer,
 253                         (unsigned int) start_addr, *start_addr);
 254             }
 255             return 0;
 256
 257             /* only pointed to by function pointers? */
 258         case CLOSURE_HEADER_WIDETAG:
 259         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 260             if (pointer_filter_verbose) {
 261                 fprintf(stderr,"*Wo4: %x %x %x\n", (unsigned int) pointer,
 262                         (unsigned int) start_addr, *start_addr);
 263             }
 264             return 0;
 265
 266         case INSTANCE_HEADER_WIDETAG:
 267             if (pointer_filter_verbose) {
 268                 fprintf(stderr,"*Wo5: %x %x %x\n", (unsigned int) pointer,
 269                         (unsigned int) start_addr, *start_addr);
 270             }
 271             return 0;
 272
 273             /* the valid other immediate pointer objects */
 274         case SIMPLE_VECTOR_WIDETAG:
 275         case RATIO_WIDETAG:
 276         case COMPLEX_WIDETAG:
 277 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 278         case COMPLEX_SINGLE_FLOAT_WIDETAG:
 279 #endif
 280 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 281         case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 282 #endif
 283 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 284         case COMPLEX_LONG_FLOAT_WIDETAG:
 285 #endif
 286         case SIMPLE_ARRAY_WIDETAG:
 287         case COMPLEX_BASE_STRING_WIDETAG:
 288 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
 289         case COMPLEX_CHARACTER_STRING_WIDETAG:
 290 #endif
 291         case COMPLEX_VECTOR_NIL_WIDETAG:
 292         case COMPLEX_BIT_VECTOR_WIDETAG:
 293         case COMPLEX_VECTOR_WIDETAG:
 294         case COMPLEX_ARRAY_WIDETAG:
 295         case VALUE_CELL_HEADER_WIDETAG:
 296         case SYMBOL_HEADER_WIDETAG:
 297         case FDEFN_WIDETAG:
 298         case CODE_HEADER_WIDETAG:
 299         case BIGNUM_WIDETAG:
 300         case SINGLE_FLOAT_WIDETAG:
 301         case DOUBLE_FLOAT_WIDETAG:
 302 #ifdef LONG_FLOAT_WIDETAG
 303         case LONG_FLOAT_WIDETAG:
 304 #endif
 305         case SIMPLE_ARRAY_NIL_WIDETAG:
 306         case SIMPLE_BASE_STRING_WIDETAG:
 307 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
 308         case SIMPLE_CHARACTER_STRING_WIDETAG:
 309 #endif
 310         case SIMPLE_BIT_VECTOR_WIDETAG:
 311         case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 312         case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 313         case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 314         case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 315         case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 316         case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 317         case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 318         case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 319         case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 320 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 321         case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 322 #endif
 323 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 324         case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 325 #endif
 326 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 327         case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 328 #endif
 329 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 330         case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 331 #endif
 332         case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 333         case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 334 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 335         case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 336 #endif
 337 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 338         case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 339 #endif
 340 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 341         case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 342 #endif
 343 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 344         case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 345 #endif
 346         case SAP_WIDETAG:
 347         case WEAK_POINTER_WIDETAG:
 348             break;
 349
 350         default:
 351             if (pointer_filter_verbose) {
 352                 fprintf(stderr,"*Wo6: %x %x %x\n", (unsigned int) pointer,
 353                         (unsigned int) start_addr, *start_addr);
 354             }
 355             return 0;
 356         }
 357         break;
 358     default:
 359         if (pointer_filter_verbose) {
 360             fprintf(stderr,"*W?: %x %x %x\n", (unsigned int) pointer,
 361                     (unsigned int) start_addr, *start_addr);
 362         }
 363         return 0;
 364     }
 365
 366     /* looks good */
 367     return 1;
 368 }
 369
 370 #define MAX_STACK_POINTERS 256
 371 lispobj *valid_stack_locations[MAX_STACK_POINTERS];
 372 unsigned int num_valid_stack_locations;
 373
 374 #define MAX_STACK_RETURN_ADDRESSES 128
 375 lispobj *valid_stack_ra_locations[MAX_STACK_RETURN_ADDRESSES];
 376 lispobj *valid_stack_ra_code_objects[MAX_STACK_RETURN_ADDRESSES];
 377 unsigned int num_valid_stack_ra_locations;
 378
 379 /* Identify valid stack slots. */
 380 static void
 381 setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
 382 {
 383     lispobj *sp = lowaddr;
 384     num_valid_stack_locations = 0;
 385     num_valid_stack_ra_locations = 0;
 386     for (sp = lowaddr; sp < base; sp++) {
 387         lispobj thing = *sp;
 388         /* Find the object start address */
 389         lispobj *start_addr = search_dynamic_space((void *)thing);
 390         if (start_addr) {
 391             /* We need to allow raw pointers into Code objects for
 392              * return addresses. This will also pick up pointers to
 393              * functions in code objects. */
 394             if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
 395                 /* FIXME asserting here is a really dumb thing to do.
 396                  * If we've overflowed some arbitrary static limit, we
 397                  * should just refuse to purify, instead of killing
 398                  * the whole lisp session
 399                  */
 400                 gc_assert(num_valid_stack_ra_locations <
 401                           MAX_STACK_RETURN_ADDRESSES);
 402                 valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
 403                 valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
 404                     (lispobj *)((int)start_addr + OTHER_POINTER_LOWTAG);
 405             } else {
 406                 if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
 407                     gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
 408                     valid_stack_locations[num_valid_stack_locations++] = sp;
 409                 }
 410             }
 411         }
 412     }
 413     if (pointer_filter_verbose) {
 414         fprintf(stderr, "number of valid stack pointers = %d\n",
 415                 num_valid_stack_locations);
 416         fprintf(stderr, "number of stack return addresses = %d\n",
 417                 num_valid_stack_ra_locations);
 418     }
 419 }
 420
 421 static void
 422 pscav_i386_stack(void)
 423 {
 424     int i;
 425
 426     for (i = 0; i < num_valid_stack_locations; i++)
 427         pscav(valid_stack_locations[i], 1, 0);
 428
 429     for (i = 0; i < num_valid_stack_ra_locations; i++) {
 430         lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
 431         pscav(&code_obj, 1, 0);
 432         if (pointer_filter_verbose) {
 433             fprintf(stderr,"*C moved RA %x to %x; for code object %x to %x\n",
 434                     *valid_stack_ra_locations[i],
 435                     (int)(*valid_stack_ra_locations[i])
 436                     - ((int)valid_stack_ra_code_objects[i] - (int)code_obj),
 437                     (unsigned int) valid_stack_ra_code_objects[i], code_obj);
 438         }
 439         *valid_stack_ra_locations[i] =
 440             ((int)(*valid_stack_ra_locations[i])
 441              - ((int)valid_stack_ra_code_objects[i] - (int)code_obj));
 442     }
 443 }
 444 #endif
 445 #endif
 446
 447 \f
 448 static void
 449 pscav_later(lispobj *where, int count)
 450 {
 451     struct later *new;
 452
 453     if (count > LATERMAXCOUNT) {
 454         while (count > LATERMAXCOUNT) {
 455             pscav_later(where, LATERMAXCOUNT);
 456             count -= LATERMAXCOUNT;
 457             where += LATERMAXCOUNT;
 458         }
 459     }
 460     else {
 461         if (later_blocks == NULL || later_count == LATERBLOCKSIZE ||
 462             (later_count == LATERBLOCKSIZE-1 && count > 1)) {
 463             new  = (struct later *)malloc(sizeof(struct later));
 464             new->next = later_blocks;
 465             if (later_blocks && later_count < LATERBLOCKSIZE)
 466                 later_blocks->u[later_count].ptr = NULL;
 467             later_blocks = new;
 468             later_count = 0;
 469         }
 470
 471         if (count != 1)
 472             later_blocks->u[later_count++].count = count;
 473         later_blocks->u[later_count++].ptr = where;
 474     }
 475 }
 476
 477 static lispobj
 478 ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 479 {
 480     int nwords;
 481     lispobj result, *new, *old;
 482
 483     nwords = 1 + HeaderValue(header);
 484
 485     /* Allocate it */
 486     old = (lispobj *)native_pointer(thing);
 487     new = newspace_alloc(nwords,constant);
 488
 489     /* Copy it. */
 490     bcopy(old, new, nwords * sizeof(lispobj));
 491
 492     /* Deposit forwarding pointer. */
 493     result = make_lispobj(new, lowtag_of(thing));
 494     *old = result;
 495
 496     /* Scavenge it. */
 497     pscav(new, nwords, constant);
 498
 499     return result;
 500 }
 501
 502 /* We need to look at the layout to see whether it is a pure structure
 503  * class, and only then can we transport as constant. If it is pure,
 504  * we can ALWAYS transport as a constant. */
 505 static lispobj
 506 ptrans_instance(lispobj thing, lispobj header, boolean /* ignored */ constant)
 507 {
 508     lispobj layout = ((struct instance *)native_pointer(thing))->slots[0];
 509     lispobj pure = ((struct instance *)native_pointer(layout))->slots[15];
 510
 511     switch (pure) {
 512     case T:
 513         return (ptrans_boxed(thing, header, 1));
 514     case NIL:
 515         return (ptrans_boxed(thing, header, 0));
 516     case 0:
 517         {
 518             /* Substructure: special case for the COMPACT-INFO-ENVs,
 519              * where the instance may have a point to the dynamic
 520              * space placed into it (e.g. the cache-name slot), but
 521              * the lists and arrays at the time of a purify can be
 522              * moved to the RO space. */
 523             int nwords;
 524             lispobj result, *new, *old;
 525
 526             nwords = 1 + HeaderValue(header);
 527
 528             /* Allocate it */
 529             old = (lispobj *)native_pointer(thing);
 530             new = newspace_alloc(nwords, 0); /*  inconstant */
 531
 532             /* Copy it. */
 533             bcopy(old, new, nwords * sizeof(lispobj));
 534
 535             /* Deposit forwarding pointer. */
 536             result = make_lispobj(new, lowtag_of(thing));
 537             *old = result;
 538
 539             /* Scavenge it. */
 540             pscav(new, nwords, 1);
 541
 542             return result;
 543         }
 544     default:
 545         gc_abort();
 546         return NIL; /* dummy value: return something ... */
 547     }
 548 }
 549
 550 static lispobj
 551 ptrans_fdefn(lispobj thing, lispobj header)
 552 {
 553     int nwords;
 554     lispobj result, *new, *old, oldfn;
 555     struct fdefn *fdefn;
 556
 557     nwords = 1 + HeaderValue(header);
 558
 559     /* Allocate it */
 560     old = (lispobj *)native_pointer(thing);
 561     new = newspace_alloc(nwords, 0);    /* inconstant */
 562
 563     /* Copy it. */
 564     bcopy(old, new, nwords * sizeof(lispobj));
 565
 566     /* Deposit forwarding pointer. */
 567     result = make_lispobj(new, lowtag_of(thing));
 568     *old = result;
 569
 570     /* Scavenge the function. */
 571     fdefn = (struct fdefn *)new;
 572     oldfn = fdefn->fun;
 573     pscav(&fdefn->fun, 1, 0);
 574     if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
 575         fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 576
 577     return result;
 578 }
 579
 580 static lispobj
 581 ptrans_unboxed(lispobj thing, lispobj header)
 582 {
 583     int nwords;
 584     lispobj result, *new, *old;
 585
 586     nwords = 1 + HeaderValue(header);
 587
 588     /* Allocate it */
 589     old = (lispobj *)native_pointer(thing);
 590     new = newspace_alloc(nwords,1);     /* always constant */
 591
 592     /* copy it. */
 593     bcopy(old, new, nwords * sizeof(lispobj));
 594
 595     /* Deposit forwarding pointer. */
 596     result = make_lispobj(new , lowtag_of(thing));
 597     *old = result;
 598
 599     return result;
 600 }
 601
 602 static lispobj
 603 ptrans_vector(lispobj thing, int bits, int extra,
 604               boolean boxed, boolean constant)
 605 {
 606     struct vector *vector;
 607     int nwords;
 608     lispobj result, *new;
 609
 610     vector = (struct vector *)native_pointer(thing);
 611     nwords = 2 + (CEILING((fixnum_value(vector->length)+extra)*bits,32)>>5);
 612
 613     new=newspace_alloc(nwords, (constant || !boxed));
 614     bcopy(vector, new, nwords * sizeof(lispobj));
 615
 616     result = make_lispobj(new, lowtag_of(thing));
 617     vector->header = result;
 618
 619     if (boxed)
 620         pscav(new, nwords, constant);
 621
 622     return result;
 623 }
 624
 625 #ifdef LISP_FEATURE_X86
 626 static void
 627 apply_code_fixups_during_purify(struct code *old_code, struct code *new_code)
 628 {
 629     int nheader_words, ncode_words, nwords;
 630     void  *constants_start_addr, *constants_end_addr;
 631     void  *code_start_addr, *code_end_addr;
 632     lispobj fixups = NIL;
 633     unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
 634     struct vector *fixups_vector;
 635
 636     ncode_words = fixnum_value(new_code->code_size);
 637     nheader_words = HeaderValue(*(lispobj *)new_code);
 638     nwords = ncode_words + nheader_words;
 639
 640     constants_start_addr = (void *)new_code + 5*4;
 641     constants_end_addr = (void *)new_code + nheader_words*4;
 642     code_start_addr = (void *)new_code + nheader_words*4;
 643     code_end_addr = (void *)new_code + nwords*4;
 644
 645     /* The first constant should be a pointer to the fixups for this
 646      * code objects. Check. */
 647     fixups = new_code->constants[0];
 648
 649     /* It will be 0 or the unbound-marker if there are no fixups, and
 650      * will be an other-pointer to a vector if it is valid. */
 651     if ((fixups==0) ||
 652         (fixups==UNBOUND_MARKER_WIDETAG) ||
 653         !is_lisp_pointer(fixups)) {
 654 #ifdef LISP_FEATURE_GENCGC
 655         /* Check for a possible errors. */
 656         sniff_code_object(new_code,displacement);
 657 #endif
 658         return;
 659     }
 660
 661     fixups_vector = (struct vector *)native_pointer(fixups);
 662
 663     /* Could be pointing to a forwarding pointer. */
 664     if (is_lisp_pointer(fixups) && (dynamic_pointer_p(fixups))
 665         && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
 666         /* If so then follow it. */
 667         fixups_vector =
 668             (struct vector *)native_pointer(*(lispobj *)fixups_vector);
 669     }
 670
 671     if (widetag_of(fixups_vector->header) ==
 672         SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
 673         /* We got the fixups for the code block. Now work through the
 674          * vector, and apply a fixup at each address. */
 675         int length = fixnum_value(fixups_vector->length);
 676         int i;
 677         for (i=0; i<length; i++) {
 678             unsigned offset = fixups_vector->data[i];
 679             /* Now check the current value of offset. */
 680             unsigned old_value =
 681                 *(unsigned *)((unsigned)code_start_addr + offset);
 682
 683             /* If it's within the old_code object then it must be an
 684              * absolute fixup (relative ones are not saved) */
 685             if ((old_value>=(unsigned)old_code)
 686                 && (old_value<((unsigned)old_code + nwords*4)))
 687                 /* So add the dispacement. */
 688                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 689                     + displacement;
 690             else
 691                 /* It is outside the old code object so it must be a relative
 692                  * fixup (absolute fixups are not saved). So subtract the
 693                  * displacement. */
 694                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 695                     - displacement;
 696         }
 697     }
 698
 699     /* No longer need the fixups. */
 700     new_code->constants[0] = 0;
 701
 702 #ifdef LISP_FEATURE_GENCGC
 703     /* Check for possible errors. */
 704     sniff_code_object(new_code,displacement);
 705 #endif
 706 }
 707 #endif
 708
 709 static lispobj
 710 ptrans_code(lispobj thing)
 711 {
 712     struct code *code, *new;
 713     int nwords;
 714     lispobj func, result;
 715
 716     code = (struct code *)native_pointer(thing);
 717     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
 718
 719     new = (struct code *)newspace_alloc(nwords,1); /* constant */
 720
 721     bcopy(code, new, nwords * sizeof(lispobj));
 722
 723 #ifdef LISP_FEATURE_X86
 724     apply_code_fixups_during_purify(code,new);
 725 #endif
 726
 727     result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 728
 729     /* Stick in a forwarding pointer for the code object. */
 730     *(lispobj *)code = result;
 731
 732     /* Put in forwarding pointers for all the functions. */
 733     for (func = code->entry_points;
 734          func != NIL;
 735          func = ((struct simple_fun *)native_pointer(func))->next) {
 736
 737         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 738
 739         *(lispobj *)native_pointer(func) = result + (func - thing);
 740     }
 741
 742     /* Arrange to scavenge the debug info later. */
 743     pscav_later(&new->debug_info, 1);
 744
 745     /* FIXME: why would this be a fixnum? */
 746     /* "why" is a hard word, but apparently for compiled functions the
 747        trace_table_offset contains the length of the instructions, as
 748        a fixnum.  See CODE-INST-AREA-LENGTH in
 749        src/compiler/target-disassem.lisp.  -- CSR, 2004-01-08 */
 750     if (!(fixnump(new->trace_table_offset)))
 751 #if 0
 752         pscav(&new->trace_table_offset, 1, 0);
 753 #else
 754         new->trace_table_offset = NIL; /* limit lifetime */
 755 #endif
 756
 757     /* Scavenge the constants. */
 758     pscav(new->constants, HeaderValue(new->header)-5, 1);
 759
 760     /* Scavenge all the functions. */
 761     pscav(&new->entry_points, 1, 1);
 762     for (func = new->entry_points;
 763          func != NIL;
 764          func = ((struct simple_fun *)native_pointer(func))->next) {
 765         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 766         gc_assert(!dynamic_pointer_p(func));
 767
 768 #ifdef LISP_FEATURE_X86
 769         /* Temporarily convert the self pointer to a real function pointer. */
 770         ((struct simple_fun *)native_pointer(func))->self
 771             -= FUN_RAW_ADDR_OFFSET;
 772 #endif
 773         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 774 #ifdef LISP_FEATURE_X86
 775         ((struct simple_fun *)native_pointer(func))->self
 776             += FUN_RAW_ADDR_OFFSET;
 777 #endif
 778         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
 779     }
 780
 781     return result;
 782 }
 783
 784 static lispobj
 785 ptrans_func(lispobj thing, lispobj header)
 786 {
 787     int nwords;
 788     lispobj code, *new, *old, result;
 789     struct simple_fun *function;
 790
 791     /* Thing can either be a function header, a closure function
 792      * header, a closure, or a funcallable-instance. If it's a closure
 793      * or a funcallable-instance, we do the same as ptrans_boxed.
 794      * Otherwise we have to do something strange, 'cause it is buried
 795      * inside a code object. */
 796
 797     if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG) {
 798
 799         /* We can only end up here if the code object has not been
 800          * scavenged, because if it had been scavenged, forwarding pointers
 801          * would have been left behind for all the entry points. */
 802
 803         function = (struct simple_fun *)native_pointer(thing);
 804         code =
 805             make_lispobj
 806             ((native_pointer(thing) -
 807               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 808
 809         /* This will cause the function's header to be replaced with a
 810          * forwarding pointer. */
 811
 812         ptrans_code(code);
 813
 814         /* So we can just return that. */
 815         return function->header;
 816     }
 817     else {
 818         /* It's some kind of closure-like thing. */
 819         nwords = 1 + HeaderValue(header);
 820         old = (lispobj *)native_pointer(thing);
 821
 822         /* Allocate the new one.  FINs *must* not go in read_only
 823          * space.  Closures can; they never change */
 824
 825         new = newspace_alloc
 826             (nwords,(widetag_of(header)!=FUNCALLABLE_INSTANCE_HEADER_WIDETAG));
 827
 828         /* Copy it. */
 829         bcopy(old, new, nwords * sizeof(lispobj));
 830
 831         /* Deposit forwarding pointer. */
 832         result = make_lispobj(new, lowtag_of(thing));
 833         *old = result;
 834
 835         /* Scavenge it. */
 836         pscav(new, nwords, 0);
 837
 838         return result;
 839     }
 840 }
 841
 842 static lispobj
 843 ptrans_returnpc(lispobj thing, lispobj header)
 844 {
 845     lispobj code, new;
 846
 847     /* Find the corresponding code object. */
 848     code = thing - HeaderValue(header)*sizeof(lispobj);
 849
 850     /* Make sure it's been transported. */
 851     new = *(lispobj *)native_pointer(code);
 852     if (!forwarding_pointer_p(new))
 853         new = ptrans_code(code);
 854
 855     /* Maintain the offset: */
 856     return new + (thing - code);
 857 }
 858
 859 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 860
 861 static lispobj
 862 ptrans_list(lispobj thing, boolean constant)
 863 {
 864     struct cons *old, *new, *orig;
 865     int length;
 866
 867     orig = (struct cons *) newspace_alloc(0,constant);
 868     length = 0;
 869
 870     do {
 871         /* Allocate a new cons cell. */
 872         old = (struct cons *)native_pointer(thing);
 873         new = (struct cons *) newspace_alloc(WORDS_PER_CONS,constant);
 874
 875         /* Copy the cons cell and keep a pointer to the cdr. */
 876         new->car = old->car;
 877         thing = new->cdr = old->cdr;
 878
 879         /* Set up the forwarding pointer. */
 880         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 881
 882         /* And count this cell. */
 883         length++;
 884     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 885              dynamic_pointer_p(thing) &&
 886              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 887
 888     /* Scavenge the list we just copied. */
 889     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 890
 891     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 892 }
 893
 894 static lispobj
 895 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 896 {
 897     switch (widetag_of(header)) {
 898         /* FIXME: this needs a reindent */
 899       case BIGNUM_WIDETAG:
 900       case SINGLE_FLOAT_WIDETAG:
 901       case DOUBLE_FLOAT_WIDETAG:
 902 #ifdef LONG_FLOAT_WIDETAG
 903       case LONG_FLOAT_WIDETAG:
 904 #endif
 905 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 906       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 907 #endif
 908 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 909       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 910 #endif
 911 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 912       case COMPLEX_LONG_FLOAT_WIDETAG:
 913 #endif
 914       case SAP_WIDETAG:
 915           return ptrans_unboxed(thing, header);
 916
 917       case RATIO_WIDETAG:
 918       case COMPLEX_WIDETAG:
 919       case SIMPLE_ARRAY_WIDETAG:
 920       case COMPLEX_BASE_STRING_WIDETAG:
 921 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
 922     case COMPLEX_CHARACTER_STRING_WIDETAG:
 923 #endif
 924       case COMPLEX_BIT_VECTOR_WIDETAG:
 925       case COMPLEX_VECTOR_NIL_WIDETAG:
 926       case COMPLEX_VECTOR_WIDETAG:
 927       case COMPLEX_ARRAY_WIDETAG:
 928         return ptrans_boxed(thing, header, constant);
 929
 930       case VALUE_CELL_HEADER_WIDETAG:
 931       case WEAK_POINTER_WIDETAG:
 932         return ptrans_boxed(thing, header, 0);
 933
 934       case SYMBOL_HEADER_WIDETAG:
 935         return ptrans_boxed(thing, header, 0);
 936
 937       case SIMPLE_ARRAY_NIL_WIDETAG:
 938         return ptrans_vector(thing, 0, 0, 0, constant);
 939
 940       case SIMPLE_BASE_STRING_WIDETAG:
 941         return ptrans_vector(thing, 8, 1, 0, constant);
 942
 943 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
 944     case SIMPLE_CHARACTER_STRING_WIDETAG:
 945         return ptrans_vector(thing, 32, 1, 0, constant);
 946 #endif
 947
 948       case SIMPLE_BIT_VECTOR_WIDETAG:
 949         return ptrans_vector(thing, 1, 0, 0, constant);
 950
 951       case SIMPLE_VECTOR_WIDETAG:
 952         return ptrans_vector(thing, 32, 0, 1, constant);
 953
 954       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 955         return ptrans_vector(thing, 2, 0, 0, constant);
 956
 957       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 958         return ptrans_vector(thing, 4, 0, 0, constant);
 959
 960       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 961 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 962       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 963       case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 964 #endif
 965         return ptrans_vector(thing, 8, 0, 0, constant);
 966
 967       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 968 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 969       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 970       case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 971 #endif
 972         return ptrans_vector(thing, 16, 0, 0, constant);
 973
 974       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 975 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 976       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 977       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 978 #endif
 979 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 980       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 981       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 982 #endif
 983         return ptrans_vector(thing, 32, 0, 0, constant);
 984
 985       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 986         return ptrans_vector(thing, 32, 0, 0, constant);
 987
 988       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 989         return ptrans_vector(thing, 64, 0, 0, constant);
 990
 991 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 992       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 993 #ifdef LISP_FEATURE_X86
 994         return ptrans_vector(thing, 96, 0, 0, constant);
 995 #endif
 996 #ifdef sparc
 997         return ptrans_vector(thing, 128, 0, 0, constant);
 998 #endif
 999 #endif
1000
1001 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1002       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1003         return ptrans_vector(thing, 64, 0, 0, constant);
1004 #endif
1005
1006 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1007       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1008         return ptrans_vector(thing, 128, 0, 0, constant);
1009 #endif
1010
1011 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1012       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1013 #ifdef LISP_FEATURE_X86
1014         return ptrans_vector(thing, 192, 0, 0, constant);
1015 #endif
1016 #ifdef sparc
1017         return ptrans_vector(thing, 256, 0, 0, constant);
1018 #endif
1019 #endif
1020
1021       case CODE_HEADER_WIDETAG:
1022         return ptrans_code(thing);
1023
1024       case RETURN_PC_HEADER_WIDETAG:
1025         return ptrans_returnpc(thing, header);
1026
1027       case FDEFN_WIDETAG:
1028         return ptrans_fdefn(thing, header);
1029
1030       default:
1031         /* Should only come across other pointers to the above stuff. */
1032         gc_abort();
1033         return NIL;
1034     }
1035 }
1036
1037 static int
1038 pscav_fdefn(struct fdefn *fdefn)
1039 {
1040     boolean fix_func;
1041
1042     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
1043     pscav(&fdefn->name, 1, 1);
1044     pscav(&fdefn->fun, 1, 0);
1045     if (fix_func)
1046         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
1047     return sizeof(struct fdefn) / sizeof(lispobj);
1048 }
1049
1050 #ifdef LISP_FEATURE_X86
1051 /* now putting code objects in static space */
1052 static int
1053 pscav_code(struct code*code)
1054 {
1055     int nwords;
1056     lispobj func;
1057     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
1058
1059     /* Arrange to scavenge the debug info later. */
1060     pscav_later(&code->debug_info, 1);
1061
1062     /* Scavenge the constants. */
1063     pscav(code->constants, HeaderValue(code->header)-5, 1);
1064
1065     /* Scavenge all the functions. */
1066     pscav(&code->entry_points, 1, 1);
1067     for (func = code->entry_points;
1068          func != NIL;
1069          func = ((struct simple_fun *)native_pointer(func))->next) {
1070         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
1071         gc_assert(!dynamic_pointer_p(func));
1072
1073 #ifdef LISP_FEATURE_X86
1074         /* Temporarily convert the self pointer to a real function
1075          * pointer. */
1076         ((struct simple_fun *)native_pointer(func))->self
1077             -= FUN_RAW_ADDR_OFFSET;
1078 #endif
1079         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
1080 #ifdef LISP_FEATURE_X86
1081         ((struct simple_fun *)native_pointer(func))->self
1082             += FUN_RAW_ADDR_OFFSET;
1083 #endif
1084         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
1085     }
1086
1087     return CEILING(nwords,2);
1088 }
1089 #endif
1090
1091 static lispobj *
1092 pscav(lispobj *addr, int nwords, boolean constant)
1093 {
1094     lispobj thing, *thingp, header;
1095     int count = 0; /* (0 = dummy init value to stop GCC warning) */
1096     struct vector *vector;
1097
1098     while (nwords > 0) {
1099         thing = *addr;
1100         if (is_lisp_pointer(thing)) {
1101             /* It's a pointer. Is it something we might have to move? */
1102             if (dynamic_pointer_p(thing)) {
1103                 /* Maybe. Have we already moved it? */
1104                 thingp = (lispobj *)native_pointer(thing);
1105                 header = *thingp;
1106                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
1107                     /* Yep, so just copy the forwarding pointer. */
1108                     thing = header;
1109                 else {
1110                     /* Nope, copy the object. */
1111                     switch (lowtag_of(thing)) {
1112                       case FUN_POINTER_LOWTAG:
1113                         thing = ptrans_func(thing, header);
1114                         break;
1115
1116                       case LIST_POINTER_LOWTAG:
1117                         thing = ptrans_list(thing, constant);
1118                         break;
1119
1120                       case INSTANCE_POINTER_LOWTAG:
1121                         thing = ptrans_instance(thing, header, constant);
1122                         break;
1123
1124                       case OTHER_POINTER_LOWTAG:
1125                         thing = ptrans_otherptr(thing, header, constant);
1126                         break;
1127
1128                       default:
1129                         /* It was a pointer, but not one of them? */
1130                         gc_abort();
1131                     }
1132                 }
1133                 *addr = thing;
1134             }
1135             count = 1;
1136         }
1137         else if (thing & 3) {   /* FIXME: 3?  not 2? */
1138             /* It's an other immediate. Maybe the header for an unboxed */
1139             /* object. */
1140             switch (widetag_of(thing)) {
1141               case BIGNUM_WIDETAG:
1142               case SINGLE_FLOAT_WIDETAG:
1143               case DOUBLE_FLOAT_WIDETAG:
1144 #ifdef LONG_FLOAT_WIDETAG
1145               case LONG_FLOAT_WIDETAG:
1146 #endif
1147               case SAP_WIDETAG:
1148                 /* It's an unboxed simple object. */
1149                 count = HeaderValue(thing)+1;
1150                 break;
1151
1152               case SIMPLE_VECTOR_WIDETAG:
1153                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
1154                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
1155                         SIMPLE_VECTOR_WIDETAG;
1156                   }
1157                 count = 1;
1158                 break;
1159
1160               case SIMPLE_ARRAY_NIL_WIDETAG:
1161                 count = 2;
1162                 break;
1163
1164               case SIMPLE_BASE_STRING_WIDETAG:
1165                 vector = (struct vector *)addr;
1166                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,8)+2,2);
1167                 break;
1168
1169 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
1170             case SIMPLE_CHARACTER_STRING_WIDETAG:
1171                 vector = (struct vector *)addr;
1172                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,32)+2,2);
1173                 break;
1174 #endif
1175
1176               case SIMPLE_BIT_VECTOR_WIDETAG:
1177                 vector = (struct vector *)addr;
1178                 count = CEILING(NWORDS(fixnum_value(vector->length),1)+2,2);
1179                 break;
1180
1181               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1182                 vector = (struct vector *)addr;
1183                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
1184                 break;
1185
1186               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1187                 vector = (struct vector *)addr;
1188                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
1189                 break;
1190
1191               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1192 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1193               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1194               case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
1195 #endif
1196                 vector = (struct vector *)addr;
1197                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
1198                 break;
1199
1200               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1201 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1202               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1203               case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
1204 #endif
1205                 vector = (struct vector *)addr;
1206                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
1207                 break;
1208
1209               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1210 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1211               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1212               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
1213 #endif
1214 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1215               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1216               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
1217 #endif
1218                 vector = (struct vector *)addr;
1219                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
1220                 break;
1221
1222 #if N_WORD_BITS == 64
1223               case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
1224 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
1225               case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
1226               case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
1227 #endif
1228 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
1229               case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
1230               case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
1231 #endif
1232                 vector = (struct vector *)addr;
1233                 count = CEILING(NWORDS(fixnum_value(vector->length),64)+2,2);
1234                 break;
1235 #endif
1236
1237               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1238                 vector = (struct vector *)addr;
1239                 count = CEILING(fixnum_value(vector->length)+2,2);
1240                 break;
1241
1242               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1243 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1244               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1245 #endif
1246                 vector = (struct vector *)addr;
1247                 count = fixnum_value(vector->length)*2+2;
1248                 break;
1249
1250 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1251               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1252                 vector = (struct vector *)addr;
1253 #ifdef LISP_FEATURE_X86
1254                 count = fixnum_value(vector->length)*3+2;
1255 #endif
1256 #ifdef sparc
1257                 count = fixnum_value(vector->length)*4+2;
1258 #endif
1259                 break;
1260 #endif
1261
1262 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1263               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1264                 vector = (struct vector *)addr;
1265                 count = fixnum_value(vector->length)*4+2;
1266                 break;
1267 #endif
1268
1269 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1270               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1271                 vector = (struct vector *)addr;
1272 #ifdef LISP_FEATURE_X86
1273                 count = fixnum_value(vector->length)*6+2;
1274 #endif
1275 #ifdef sparc
1276                 count = fixnum_value(vector->length)*8+2;
1277 #endif
1278                 break;
1279 #endif
1280
1281               case CODE_HEADER_WIDETAG:
1282 #ifndef LISP_FEATURE_X86
1283                 gc_abort(); /* no code headers in static space */
1284 #else
1285                 count = pscav_code((struct code*)addr);
1286 #endif
1287                 break;
1288
1289               case SIMPLE_FUN_HEADER_WIDETAG:
1290               case RETURN_PC_HEADER_WIDETAG:
1291                 /* We should never hit any of these, 'cause they occur
1292                  * buried in the middle of code objects. */
1293                 gc_abort();
1294                 break;
1295
1296 #ifdef LISP_FEATURE_X86
1297               case CLOSURE_HEADER_WIDETAG:
1298               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
1299                 /* The function self pointer needs special care on the
1300                  * x86 because it is the real entry point. */
1301                 {
1302                   lispobj fun = ((struct closure *)addr)->fun
1303                     - FUN_RAW_ADDR_OFFSET;
1304                   pscav(&fun, 1, constant);
1305                   ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
1306                 }
1307                 count = 2;
1308                 break;
1309 #endif
1310
1311               case WEAK_POINTER_WIDETAG:
1312                 /* Weak pointers get preserved during purify, 'cause I
1313                  * don't feel like figuring out how to break them. */
1314                 pscav(addr+1, 2, constant);
1315                 count = 4;
1316                 break;
1317
1318               case FDEFN_WIDETAG:
1319                 /* We have to handle fdefn objects specially, so we
1320                  * can fix up the raw function address. */
1321                 count = pscav_fdefn((struct fdefn *)addr);
1322                 break;
1323
1324               default:
1325                 count = 1;
1326                 break;
1327             }
1328         }
1329         else {
1330             /* It's a fixnum. */
1331             count = 1;
1332         }
1333
1334         addr += count;
1335         nwords -= count;
1336     }
1337
1338     return addr;
1339 }
1340
1341 int
1342 purify(lispobj static_roots, lispobj read_only_roots)
1343 {
1344     lispobj *clean;
1345     int count, i;
1346     struct later *laters, *next;
1347     struct thread *thread;
1348
1349     if(all_threads->next) {
1350         /* FIXME: there should be _some_ sensible error reporting
1351          * convention.  See following comment too */
1352         fprintf(stderr,"Can't purify when more than one thread exists\n");
1353         fflush(stderr);
1354         return 0;
1355     }
1356
1357 #ifdef PRINTNOISE
1358     printf("[doing purification:");
1359     fflush(stdout);
1360 #endif
1361 #ifdef LISP_FEATURE_GENCGC
1362     gc_alloc_update_all_page_tables();
1363 #endif
1364     for_each_thread(thread)
1365         if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)) != 0) {
1366         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
1367          * its error simply by a. printing a string b. to stdout instead
1368          * of stderr. */
1369         printf(" Ack! Can't purify interrupt contexts. ");
1370         fflush(stdout);
1371         return 0;
1372     }
1373
1374 #if defined(LISP_FEATURE_X86)
1375     dynamic_space_free_pointer =
1376       (lispobj*)SymbolValue(ALLOCATION_POINTER,0);
1377 #endif
1378
1379     read_only_end = read_only_free =
1380         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
1381     static_end = static_free =
1382         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
1383
1384 #ifdef PRINTNOISE
1385     printf(" roots");
1386     fflush(stdout);
1387 #endif
1388
1389 #if (defined(LISP_FEATURE_GENCGC) && defined(LISP_FEATURE_X86))
1390     /* note this expects only one thread to be active.  We'd have to
1391      * stop all the others in the same way as GC does if we wanted
1392      * PURIFY to work when >1 thread exists */
1393     setup_i386_stack_scav(((&static_roots)-2),
1394                           ((void *)all_threads->control_stack_end));
1395 #endif
1396
1397     pscav(&static_roots, 1, 0);
1398     pscav(&read_only_roots, 1, 1);
1399
1400 #ifdef PRINTNOISE
1401     printf(" handlers");
1402     fflush(stdout);
1403 #endif
1404     pscav((lispobj *) all_threads->interrupt_data->interrupt_handlers,
1405           sizeof(all_threads->interrupt_data->interrupt_handlers)
1406           / sizeof(lispobj),
1407           0);
1408
1409 #ifdef PRINTNOISE
1410     printf(" stack");
1411     fflush(stdout);
1412 #endif
1413 #ifndef LISP_FEATURE_X86
1414     pscav((lispobj *)all_threads->control_stack_start,
1415           current_control_stack_pointer -
1416           all_threads->control_stack_start,
1417           0);
1418 #else
1419 #ifdef LISP_FEATURE_GENCGC
1420     pscav_i386_stack();
1421 #endif
1422 #endif
1423
1424 #ifdef PRINTNOISE
1425     printf(" bindings");
1426     fflush(stdout);
1427 #endif
1428 #if !defined(LISP_FEATURE_X86)
1429     pscav( (lispobj *)all_threads->binding_stack_start,
1430           (lispobj *)current_binding_stack_pointer -
1431            all_threads->binding_stack_start,
1432           0);
1433 #else
1434     for_each_thread(thread) {
1435         pscav( (lispobj *)thread->binding_stack_start,
1436                (lispobj *)SymbolValue(BINDING_STACK_POINTER,thread) -
1437                (lispobj *)thread->binding_stack_start,
1438           0);
1439         pscav( (lispobj *) (thread+1),
1440                fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
1441                (sizeof (struct thread))/(sizeof (lispobj)),
1442           0);
1443     }
1444
1445
1446 #endif
1447
1448     /* The original CMU CL code had scavenge-read-only-space code
1449      * controlled by the Lisp-level variable
1450      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
1451      * wasn't documented under what circumstances it was useful or
1452      * safe to turn it on, so it's been turned off in SBCL. If you
1453      * want/need this functionality, and can test and document it,
1454      * please submit a patch. */
1455 #if 0
1456     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
1457         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
1458       unsigned  read_only_space_size =
1459           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
1460           (lispobj *)READ_ONLY_SPACE_START;
1461       fprintf(stderr,
1462               "scavenging read only space: %d bytes\n",
1463               read_only_space_size * sizeof(lispobj));
1464       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
1465     }
1466 #endif
1467
1468 #ifdef PRINTNOISE
1469     printf(" static");
1470     fflush(stdout);
1471 #endif
1472     clean = (lispobj *)STATIC_SPACE_START;
1473     do {
1474         while (clean != static_free)
1475             clean = pscav(clean, static_free - clean, 0);
1476         laters = later_blocks;
1477         count = later_count;
1478         later_blocks = NULL;
1479         later_count = 0;
1480         while (laters != NULL) {
1481             for (i = 0; i < count; i++) {
1482                 if (laters->u[i].count == 0) {
1483                     ;
1484                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1485                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1486                     i++;
1487                 } else {
1488                     pscav(laters->u[i].ptr, 1, 1);
1489                 }
1490             }
1491             next = laters->next;
1492             free(laters);
1493             laters = next;
1494             count = LATERBLOCKSIZE;
1495         }
1496     } while (clean != static_free || later_blocks != NULL);
1497
1498 #ifdef PRINTNOISE
1499     printf(" cleanup");
1500     fflush(stdout);
1501 #endif
1502
1503     os_zero((os_vm_address_t) current_dynamic_space,
1504             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
1505
1506     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
1507      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
1508 #ifndef LISP_FEATURE_X86
1509     os_zero((os_vm_address_t) current_control_stack_pointer,
1510             (os_vm_size_t)
1511             ((all_threads->control_stack_end -
1512               current_control_stack_pointer) * sizeof(lispobj)));
1513 #endif
1514
1515     /* It helps to update the heap free pointers so that free_heap can
1516      * verify after it's done. */
1517     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free,0);
1518     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free,0);
1519
1520 #if !defined(ALLOCATION_POINTER)
1521     dynamic_space_free_pointer = current_dynamic_space;
1522     set_auto_gc_trigger(bytes_consed_between_gcs);
1523 #else
1524 #if defined LISP_FEATURE_GENCGC
1525     gc_free_heap();
1526 #else
1527 #error unsupported case /* in CMU CL, was "ibmrt using GC" */
1528 #endif
1529 #endif
1530
1531 #ifdef PRINTNOISE
1532     printf(" done]\n");
1533     fflush(stdout);
1534 #endif
1535     return 0;
1536 }