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 #if (defined(LISP_FEATURE_SB_THREAD) && defined(LISP_FEATURE_LINUX))
  21 #include <sys/ptrace.h>
  22 #include <linux/user.h>
  23 #endif
  24 #include <errno.h>
  25
  26 #include "runtime.h"
  27 #include "os.h"
  28 #include "sbcl.h"
  29 #include "globals.h"
  30 #include "validate.h"
  31 #include "interrupt.h"
  32 #include "purify.h"
  33 #include "interr.h"
  34 #include "gc.h"
  35 #include "gc-internal.h"
  36 #include "thread.h"
  37 #include "genesis/primitive-objects.h"
  38 #include "genesis/static-symbols.h"
  39
  40 #define PRINTNOISE
  41
  42 #if defined(__i386__)
  43 /* again, what's so special about the x86 that this is differently
  44  * visible there than on other platforms? -dan 20010125
  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 #define CEILING(x,y) (((x) + ((y) - 1)) & (~((y) - 1)))
  85 #define NWORDS(x,y) (CEILING((x),(y)) / (y))
  86
  87 /* FIXME: Shouldn't this be defined in sbcl.h?  See also notes in
  88  * cheneygc.c */
  89
  90 #ifdef sparc
  91 #define FUN_RAW_ADDR_OFFSET 0
  92 #else
  93 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
  94 #endif
  95 \f
  96 static boolean
  97 forwarding_pointer_p(lispobj obj)
  98 {
  99     lispobj *ptr = native_pointer(obj);
 100
 101     return ((static_end <= ptr && ptr <= static_free) ||
 102             (read_only_end <= ptr && ptr <= read_only_free));
 103 }
 104
 105 static boolean
 106 dynamic_pointer_p(lispobj ptr)
 107 {
 108 #ifndef __i386__
 109     return (ptr >= (lispobj)current_dynamic_space
 110             &&
 111             ptr < (lispobj)dynamic_space_free_pointer);
 112 #else
 113     /* Be more conservative, and remember, this is a maybe. */
 114     return (ptr >= (lispobj)DYNAMIC_SPACE_START
 115             &&
 116             ptr < (lispobj)dynamic_space_free_pointer);
 117 #endif
 118 }
 119
 120 \f
 121 #ifdef __i386__
 122
 123 #ifdef LISP_FEATURE_GENCGC
 124 /*
 125  * enhanced x86/GENCGC stack scavenging by Douglas Crosher
 126  *
 127  * Scavenging the stack on the i386 is problematic due to conservative
 128  * roots and raw return addresses. Here it is handled in two passes:
 129  * the first pass runs before any objects are moved and tries to
 130  * identify valid pointers and return address on the stack, the second
 131  * pass scavenges these.
 132  */
 133
 134 static unsigned pointer_filter_verbose = 0;
 135
 136 /* FIXME: This is substantially the same code as
 137  * possibly_valid_dynamic_space_pointer in gencgc.c.  The only
 138  * relevant difference seems to be that the gencgc code also checks
 139  * for raw pointers into Code objects */
 140
 141 static int
 142 valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
 143 {
 144     /* If it's not a return address then it needs to be a valid Lisp
 145      * pointer. */
 146     if (!is_lisp_pointer((lispobj)pointer))
 147         return 0;
 148
 149     /* Check that the object pointed to is consistent with the pointer
 150      * low tag. */
 151     switch (lowtag_of((lispobj)pointer)) {
 152     case FUN_POINTER_LOWTAG:
 153         /* Start_addr should be the enclosing code object, or a closure
 154          * header. */
 155         switch (widetag_of(*start_addr)) {
 156         case CODE_HEADER_WIDETAG:
 157             /* This case is probably caught above. */
 158             break;
 159         case CLOSURE_HEADER_WIDETAG:
 160         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 161             if ((int)pointer != ((int)start_addr+FUN_POINTER_LOWTAG)) {
 162                 if (pointer_filter_verbose) {
 163                     fprintf(stderr,"*Wf2: %x %x %x\n", (unsigned int) pointer,
 164                             (unsigned int) start_addr, *start_addr);
 165                 }
 166                 return 0;
 167             }
 168             break;
 169         default:
 170             if (pointer_filter_verbose) {
 171                 fprintf(stderr,"*Wf3: %x %x %x\n", (unsigned int) pointer,
 172                         (unsigned int) start_addr, *start_addr);
 173             }
 174             return 0;
 175         }
 176         break;
 177     case LIST_POINTER_LOWTAG:
 178         if ((int)pointer != ((int)start_addr+LIST_POINTER_LOWTAG)) {
 179             if (pointer_filter_verbose)
 180                 fprintf(stderr,"*Wl1: %x %x %x\n", (unsigned int) pointer,
 181                         (unsigned int) start_addr, *start_addr);
 182             return 0;
 183         }
 184         /* Is it plausible cons? */
 185         if ((is_lisp_pointer(start_addr[0])
 186             || ((start_addr[0] & 3) == 0) /* fixnum */
 187             || (widetag_of(start_addr[0]) == BASE_CHAR_WIDETAG)
 188             || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
 189            && (is_lisp_pointer(start_addr[1])
 190                || ((start_addr[1] & 3) == 0) /* fixnum */
 191                || (widetag_of(start_addr[1]) == BASE_CHAR_WIDETAG)
 192                || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
 193             break;
 194         } else {
 195             if (pointer_filter_verbose) {
 196                 fprintf(stderr,"*Wl2: %x %x %x\n", (unsigned int) pointer,
 197                         (unsigned int) start_addr, *start_addr);
 198             }
 199             return 0;
 200         }
 201     case INSTANCE_POINTER_LOWTAG:
 202         if ((int)pointer != ((int)start_addr+INSTANCE_POINTER_LOWTAG)) {
 203             if (pointer_filter_verbose) {
 204                 fprintf(stderr,"*Wi1: %x %x %x\n", (unsigned int) pointer,
 205                         (unsigned int) start_addr, *start_addr);
 206             }
 207             return 0;
 208         }
 209         if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
 210             if (pointer_filter_verbose) {
 211                 fprintf(stderr,"*Wi2: %x %x %x\n", (unsigned int) pointer,
 212                         (unsigned int) start_addr, *start_addr);
 213             }
 214             return 0;
 215         }
 216         break;
 217     case OTHER_POINTER_LOWTAG:
 218         if ((int)pointer != ((int)start_addr+OTHER_POINTER_LOWTAG)) {
 219             if (pointer_filter_verbose) {
 220                 fprintf(stderr,"*Wo1: %x %x %x\n", (unsigned int) pointer,
 221                         (unsigned int) start_addr, *start_addr);
 222             }
 223             return 0;
 224         }
 225         /* Is it plausible? Not a cons. XXX should check the headers. */
 226         if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
 227             if (pointer_filter_verbose) {
 228                 fprintf(stderr,"*Wo2: %x %x %x\n", (unsigned int) pointer,
 229                         (unsigned int) start_addr, *start_addr);
 230             }
 231             return 0;
 232         }
 233         switch (widetag_of(start_addr[0])) {
 234         case UNBOUND_MARKER_WIDETAG:
 235         case BASE_CHAR_WIDETAG:
 236             if (pointer_filter_verbose) {
 237                 fprintf(stderr,"*Wo3: %x %x %x\n", (unsigned int) pointer,
 238                         (unsigned int) start_addr, *start_addr);
 239             }
 240             return 0;
 241
 242             /* only pointed to by function pointers? */
 243         case CLOSURE_HEADER_WIDETAG:
 244         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 245             if (pointer_filter_verbose) {
 246                 fprintf(stderr,"*Wo4: %x %x %x\n", (unsigned int) pointer,
 247                         (unsigned int) start_addr, *start_addr);
 248             }
 249             return 0;
 250
 251         case INSTANCE_HEADER_WIDETAG:
 252             if (pointer_filter_verbose) {
 253                 fprintf(stderr,"*Wo5: %x %x %x\n", (unsigned int) pointer,
 254                         (unsigned int) start_addr, *start_addr);
 255             }
 256             return 0;
 257
 258             /* the valid other immediate pointer objects */
 259         case SIMPLE_VECTOR_WIDETAG:
 260         case RATIO_WIDETAG:
 261         case COMPLEX_WIDETAG:
 262 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 263         case COMPLEX_SINGLE_FLOAT_WIDETAG:
 264 #endif
 265 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 266         case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 267 #endif
 268 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 269         case COMPLEX_LONG_FLOAT_WIDETAG:
 270 #endif
 271         case SIMPLE_ARRAY_WIDETAG:
 272         case COMPLEX_BASE_STRING_WIDETAG:
 273         case COMPLEX_VECTOR_NIL_WIDETAG:
 274         case COMPLEX_BIT_VECTOR_WIDETAG:
 275         case COMPLEX_VECTOR_WIDETAG:
 276         case COMPLEX_ARRAY_WIDETAG:
 277         case VALUE_CELL_HEADER_WIDETAG:
 278         case SYMBOL_HEADER_WIDETAG:
 279         case FDEFN_WIDETAG:
 280         case CODE_HEADER_WIDETAG:
 281         case BIGNUM_WIDETAG:
 282         case SINGLE_FLOAT_WIDETAG:
 283         case DOUBLE_FLOAT_WIDETAG:
 284 #ifdef LONG_FLOAT_WIDETAG
 285         case LONG_FLOAT_WIDETAG:
 286 #endif
 287         case SIMPLE_ARRAY_NIL_WIDETAG:
 288         case SIMPLE_BASE_STRING_WIDETAG:
 289         case SIMPLE_BIT_VECTOR_WIDETAG:
 290         case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 291         case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 292         case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 293         case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 294         case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 295         case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 296         case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 297         case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 298         case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 299 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 300         case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 301 #endif
 302 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 303         case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 304 #endif
 305 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 306         case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 307 #endif
 308 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 309         case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 310 #endif
 311         case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 312         case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 313 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 314         case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 315 #endif
 316 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 317         case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 318 #endif
 319 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 320         case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 321 #endif
 322 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 323         case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 324 #endif
 325         case SAP_WIDETAG:
 326         case WEAK_POINTER_WIDETAG:
 327             break;
 328
 329         default:
 330             if (pointer_filter_verbose) {
 331                 fprintf(stderr,"*Wo6: %x %x %x\n", (unsigned int) pointer,
 332                         (unsigned int) start_addr, *start_addr);
 333             }
 334             return 0;
 335         }
 336         break;
 337     default:
 338         if (pointer_filter_verbose) {
 339             fprintf(stderr,"*W?: %x %x %x\n", (unsigned int) pointer,
 340                     (unsigned int) start_addr, *start_addr);
 341         }
 342         return 0;
 343     }
 344
 345     /* looks good */
 346     return 1;
 347 }
 348
 349 #define MAX_STACK_POINTERS 256
 350 lispobj *valid_stack_locations[MAX_STACK_POINTERS];
 351 unsigned int num_valid_stack_locations;
 352
 353 #define MAX_STACK_RETURN_ADDRESSES 128
 354 lispobj *valid_stack_ra_locations[MAX_STACK_RETURN_ADDRESSES];
 355 lispobj *valid_stack_ra_code_objects[MAX_STACK_RETURN_ADDRESSES];
 356 unsigned int num_valid_stack_ra_locations;
 357
 358 /* Identify valid stack slots. */
 359 static void
 360 setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
 361 {
 362     lispobj *sp = lowaddr;
 363     num_valid_stack_locations = 0;
 364     num_valid_stack_ra_locations = 0;
 365     for (sp = lowaddr; sp < base; sp++) {
 366         lispobj thing = *sp;
 367         /* Find the object start address */
 368         lispobj *start_addr = search_dynamic_space((void *)thing);
 369         if (start_addr) {
 370             /* We need to allow raw pointers into Code objects for
 371              * return addresses. This will also pick up pointers to
 372              * functions in code objects. */
 373             if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
 374                 /* FIXME asserting here is a really dumb thing to do.
 375                  * If we've overflowed some arbitrary static limit, we
 376                  * should just refuse to purify, instead of killing
 377                  * the whole lisp session
 378                  */
 379                 gc_assert(num_valid_stack_ra_locations <
 380                           MAX_STACK_RETURN_ADDRESSES);
 381                 valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
 382                 valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
 383                     (lispobj *)((int)start_addr + OTHER_POINTER_LOWTAG);
 384             } else {
 385                 if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
 386                     gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
 387                     valid_stack_locations[num_valid_stack_locations++] = sp;
 388                 }
 389             }
 390         }
 391     }
 392     if (pointer_filter_verbose) {
 393         fprintf(stderr, "number of valid stack pointers = %d\n",
 394                 num_valid_stack_locations);
 395         fprintf(stderr, "number of stack return addresses = %d\n",
 396                 num_valid_stack_ra_locations);
 397     }
 398 }
 399
 400 static void
 401 pscav_i386_stack(void)
 402 {
 403     int i;
 404
 405     for (i = 0; i < num_valid_stack_locations; i++)
 406         pscav(valid_stack_locations[i], 1, 0);
 407
 408     for (i = 0; i < num_valid_stack_ra_locations; i++) {
 409         lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
 410         pscav(&code_obj, 1, 0);
 411         if (pointer_filter_verbose) {
 412             fprintf(stderr,"*C moved RA %x to %x; for code object %x to %x\n",
 413                     *valid_stack_ra_locations[i],
 414                     (int)(*valid_stack_ra_locations[i])
 415                     - ((int)valid_stack_ra_code_objects[i] - (int)code_obj),
 416                     (unsigned int) valid_stack_ra_code_objects[i], code_obj);
 417         }
 418         *valid_stack_ra_locations[i] =
 419             ((int)(*valid_stack_ra_locations[i])
 420              - ((int)valid_stack_ra_code_objects[i] - (int)code_obj));
 421     }
 422 }
 423 #endif
 424 #endif
 425
 426 \f
 427 static void
 428 pscav_later(lispobj *where, int count)
 429 {
 430     struct later *new;
 431
 432     if (count > LATERMAXCOUNT) {
 433         while (count > LATERMAXCOUNT) {
 434             pscav_later(where, LATERMAXCOUNT);
 435             count -= LATERMAXCOUNT;
 436             where += LATERMAXCOUNT;
 437         }
 438     }
 439     else {
 440         if (later_blocks == NULL || later_count == LATERBLOCKSIZE ||
 441             (later_count == LATERBLOCKSIZE-1 && count > 1)) {
 442             new  = (struct later *)malloc(sizeof(struct later));
 443             new->next = later_blocks;
 444             if (later_blocks && later_count < LATERBLOCKSIZE)
 445                 later_blocks->u[later_count].ptr = NULL;
 446             later_blocks = new;
 447             later_count = 0;
 448         }
 449
 450         if (count != 1)
 451             later_blocks->u[later_count++].count = count;
 452         later_blocks->u[later_count++].ptr = where;
 453     }
 454 }
 455
 456 static lispobj
 457 ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 458 {
 459     int nwords;
 460     lispobj result, *new, *old;
 461
 462     nwords = 1 + HeaderValue(header);
 463
 464     /* Allocate it */
 465     old = (lispobj *)native_pointer(thing);
 466     if (constant) {
 467         new = read_only_free;
 468         read_only_free += CEILING(nwords, 2);
 469     }
 470     else {
 471         new = static_free;
 472         static_free += CEILING(nwords, 2);
 473     }
 474
 475     /* Copy it. */
 476     bcopy(old, new, nwords * sizeof(lispobj));
 477
 478     /* Deposit forwarding pointer. */
 479     result = make_lispobj(new, lowtag_of(thing));
 480     *old = result;
 481
 482     /* Scavenge it. */
 483     pscav(new, nwords, constant);
 484
 485     return result;
 486 }
 487
 488 /* We need to look at the layout to see whether it is a pure structure
 489  * class, and only then can we transport as constant. If it is pure,
 490  * we can ALWAYS transport as a constant. */
 491 static lispobj
 492 ptrans_instance(lispobj thing, lispobj header, boolean constant)
 493 {
 494     lispobj layout = ((struct instance *)native_pointer(thing))->slots[0];
 495     lispobj pure = ((struct instance *)native_pointer(layout))->slots[15];
 496
 497     switch (pure) {
 498     case T:
 499         return (ptrans_boxed(thing, header, 1));
 500     case NIL:
 501         return (ptrans_boxed(thing, header, 0));
 502     case 0:
 503         {
 504             /* Substructure: special case for the COMPACT-INFO-ENVs,
 505              * where the instance may have a point to the dynamic
 506              * space placed into it (e.g. the cache-name slot), but
 507              * the lists and arrays at the time of a purify can be
 508              * moved to the RO space. */
 509             int nwords;
 510             lispobj result, *new, *old;
 511
 512             nwords = 1 + HeaderValue(header);
 513
 514             /* Allocate it */
 515             old = (lispobj *)native_pointer(thing);
 516             new = static_free;
 517             static_free += CEILING(nwords, 2);
 518
 519             /* Copy it. */
 520             bcopy(old, new, nwords * sizeof(lispobj));
 521
 522             /* Deposit forwarding pointer. */
 523             result = make_lispobj(new, lowtag_of(thing));
 524             *old = result;
 525
 526             /* Scavenge it. */
 527             pscav(new, nwords, 1);
 528
 529             return result;
 530         }
 531     default:
 532         gc_abort();
 533         return NIL; /* dummy value: return something ... */
 534     }
 535 }
 536
 537 static lispobj
 538 ptrans_fdefn(lispobj thing, lispobj header)
 539 {
 540     int nwords;
 541     lispobj result, *new, *old, oldfn;
 542     struct fdefn *fdefn;
 543
 544     nwords = 1 + HeaderValue(header);
 545
 546     /* Allocate it */
 547     old = (lispobj *)native_pointer(thing);
 548     new = static_free;
 549     static_free += CEILING(nwords, 2);
 550
 551     /* Copy it. */
 552     bcopy(old, new, nwords * sizeof(lispobj));
 553
 554     /* Deposit forwarding pointer. */
 555     result = make_lispobj(new, lowtag_of(thing));
 556     *old = result;
 557
 558     /* Scavenge the function. */
 559     fdefn = (struct fdefn *)new;
 560     oldfn = fdefn->fun;
 561     pscav(&fdefn->fun, 1, 0);
 562     if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
 563         fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 564
 565     return result;
 566 }
 567
 568 static lispobj
 569 ptrans_unboxed(lispobj thing, lispobj header)
 570 {
 571     int nwords;
 572     lispobj result, *new, *old;
 573
 574     nwords = 1 + HeaderValue(header);
 575
 576     /* Allocate it */
 577     old = (lispobj *)native_pointer(thing);
 578     new = read_only_free;
 579     read_only_free += CEILING(nwords, 2);
 580
 581     /* Copy it. */
 582     bcopy(old, new, nwords * sizeof(lispobj));
 583
 584     /* Deposit forwarding pointer. */
 585     result = make_lispobj(new , lowtag_of(thing));
 586     *old = result;
 587
 588     return result;
 589 }
 590
 591 static lispobj
 592 ptrans_vector(lispobj thing, int bits, int extra,
 593               boolean boxed, boolean constant)
 594 {
 595     struct vector *vector;
 596     int nwords;
 597     lispobj result, *new;
 598
 599     vector = (struct vector *)native_pointer(thing);
 600     nwords = 2 + (CEILING((fixnum_value(vector->length)+extra)*bits,32)>>5);
 601
 602     if (boxed && !constant) {
 603         new = static_free;
 604         static_free += CEILING(nwords, 2);
 605     }
 606     else {
 607         new = read_only_free;
 608         read_only_free += CEILING(nwords, 2);
 609     }
 610
 611     bcopy(vector, new, nwords * sizeof(lispobj));
 612
 613     result = make_lispobj(new, lowtag_of(thing));
 614     vector->header = result;
 615
 616     if (boxed)
 617         pscav(new, nwords, constant);
 618
 619     return result;
 620 }
 621
 622 #ifdef __i386__
 623 static void
 624 apply_code_fixups_during_purify(struct code *old_code, struct code *new_code)
 625 {
 626     int nheader_words, ncode_words, nwords;
 627     void  *constants_start_addr, *constants_end_addr;
 628     void  *code_start_addr, *code_end_addr;
 629     lispobj fixups = NIL;
 630     unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
 631     struct vector *fixups_vector;
 632
 633     ncode_words = fixnum_value(new_code->code_size);
 634     nheader_words = HeaderValue(*(lispobj *)new_code);
 635     nwords = ncode_words + nheader_words;
 636
 637     constants_start_addr = (void *)new_code + 5*4;
 638     constants_end_addr = (void *)new_code + nheader_words*4;
 639     code_start_addr = (void *)new_code + nheader_words*4;
 640     code_end_addr = (void *)new_code + nwords*4;
 641
 642     /* The first constant should be a pointer to the fixups for this
 643      * code objects. Check. */
 644     fixups = new_code->constants[0];
 645
 646     /* It will be 0 or the unbound-marker if there are no fixups, and
 647      * will be an other-pointer to a vector if it is valid. */
 648     if ((fixups==0) ||
 649         (fixups==UNBOUND_MARKER_WIDETAG) ||
 650         !is_lisp_pointer(fixups)) {
 651 #ifdef LISP_FEATURE_GENCGC
 652         /* Check for a possible errors. */
 653         sniff_code_object(new_code,displacement);
 654 #endif
 655         return;
 656     }
 657
 658     fixups_vector = (struct vector *)native_pointer(fixups);
 659
 660     /* Could be pointing to a forwarding pointer. */
 661     if (is_lisp_pointer(fixups) && (dynamic_pointer_p(fixups))
 662         && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
 663         /* If so then follow it. */
 664         fixups_vector =
 665             (struct vector *)native_pointer(*(lispobj *)fixups_vector);
 666     }
 667
 668     if (widetag_of(fixups_vector->header) ==
 669         SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
 670         /* We got the fixups for the code block. Now work through the
 671          * vector, and apply a fixup at each address. */
 672         int length = fixnum_value(fixups_vector->length);
 673         int i;
 674         for (i=0; i<length; i++) {
 675             unsigned offset = fixups_vector->data[i];
 676             /* Now check the current value of offset. */
 677             unsigned old_value =
 678                 *(unsigned *)((unsigned)code_start_addr + offset);
 679
 680             /* If it's within the old_code object then it must be an
 681              * absolute fixup (relative ones are not saved) */
 682             if ((old_value>=(unsigned)old_code)
 683                 && (old_value<((unsigned)old_code + nwords*4)))
 684                 /* So add the dispacement. */
 685                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 686                     + displacement;
 687             else
 688                 /* It is outside the old code object so it must be a relative
 689                  * fixup (absolute fixups are not saved). So subtract the
 690                  * displacement. */
 691                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 692                     - displacement;
 693         }
 694     }
 695
 696     /* No longer need the fixups. */
 697     new_code->constants[0] = 0;
 698
 699 #ifdef LISP_FEATURE_GENCGC
 700     /* Check for possible errors. */
 701     sniff_code_object(new_code,displacement);
 702 #endif
 703 }
 704 #endif
 705
 706 static lispobj
 707 ptrans_code(lispobj thing)
 708 {
 709     struct code *code, *new;
 710     int nwords;
 711     lispobj func, result;
 712
 713     code = (struct code *)native_pointer(thing);
 714     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
 715
 716     new = (struct code *)read_only_free;
 717     read_only_free += CEILING(nwords, 2);
 718
 719     bcopy(code, new, nwords * sizeof(lispobj));
 720
 721 #ifdef LISP_FEATURE_X86
 722     apply_code_fixups_during_purify(code,new);
 723 #endif
 724
 725     result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 726
 727     /* Stick in a forwarding pointer for the code object. */
 728     *(lispobj *)code = result;
 729
 730     /* Put in forwarding pointers for all the functions. */
 731     for (func = code->entry_points;
 732          func != NIL;
 733          func = ((struct simple_fun *)native_pointer(func))->next) {
 734
 735         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 736
 737         *(lispobj *)native_pointer(func) = result + (func - thing);
 738     }
 739
 740     /* Arrange to scavenge the debug info later. */
 741     pscav_later(&new->debug_info, 1);
 742
 743     if (new->trace_table_offset & 0x3)
 744 #if 0
 745       pscav(&new->trace_table_offset, 1, 0);
 746 #else
 747       new->trace_table_offset = NIL; /* limit lifetime */
 748 #endif
 749
 750     /* Scavenge the constants. */
 751     pscav(new->constants, HeaderValue(new->header)-5, 1);
 752
 753     /* Scavenge all the functions. */
 754     pscav(&new->entry_points, 1, 1);
 755     for (func = new->entry_points;
 756          func != NIL;
 757          func = ((struct simple_fun *)native_pointer(func))->next) {
 758         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 759         gc_assert(!dynamic_pointer_p(func));
 760
 761 #ifdef __i386__
 762         /* Temporarly convert the self pointer to a real function pointer. */
 763         ((struct simple_fun *)native_pointer(func))->self
 764             -= FUN_RAW_ADDR_OFFSET;
 765 #endif
 766         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 767 #ifdef __i386__
 768         ((struct simple_fun *)native_pointer(func))->self
 769             += FUN_RAW_ADDR_OFFSET;
 770 #endif
 771         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
 772     }
 773
 774     return result;
 775 }
 776
 777 static lispobj
 778 ptrans_func(lispobj thing, lispobj header)
 779 {
 780     int nwords;
 781     lispobj code, *new, *old, result;
 782     struct simple_fun *function;
 783
 784     /* Thing can either be a function header, a closure function
 785      * header, a closure, or a funcallable-instance. If it's a closure
 786      * or a funcallable-instance, we do the same as ptrans_boxed.
 787      * Otherwise we have to do something strange, 'cause it is buried
 788      * inside a code object. */
 789
 790     if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG ||
 791         widetag_of(header) == CLOSURE_FUN_HEADER_WIDETAG) {
 792
 793         /* We can only end up here if the code object has not been
 794          * scavenged, because if it had been scavenged, forwarding pointers
 795          * would have been left behind for all the entry points. */
 796
 797         function = (struct simple_fun *)native_pointer(thing);
 798         code =
 799             make_lispobj
 800             ((native_pointer(thing) -
 801               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 802
 803         /* This will cause the function's header to be replaced with a
 804          * forwarding pointer. */
 805
 806         ptrans_code(code);
 807
 808         /* So we can just return that. */
 809         return function->header;
 810     }
 811     else {
 812         /* It's some kind of closure-like thing. */
 813         nwords = 1 + HeaderValue(header);
 814         old = (lispobj *)native_pointer(thing);
 815
 816         /* Allocate the new one. */
 817         if (widetag_of(header) == FUNCALLABLE_INSTANCE_HEADER_WIDETAG) {
 818             /* FINs *must* not go in read_only space. */
 819             new = static_free;
 820             static_free += CEILING(nwords, 2);
 821         }
 822         else {
 823             /* Closures can always go in read-only space, 'cause they
 824              * never change. */
 825
 826             new = read_only_free;
 827             read_only_free += CEILING(nwords, 2);
 828         }
 829         /* Copy it. */
 830         bcopy(old, new, nwords * sizeof(lispobj));
 831
 832         /* Deposit forwarding pointer. */
 833         result = make_lispobj(new, lowtag_of(thing));
 834         *old = result;
 835
 836         /* Scavenge it. */
 837         pscav(new, nwords, 0);
 838
 839         return result;
 840     }
 841 }
 842
 843 static lispobj
 844 ptrans_returnpc(lispobj thing, lispobj header)
 845 {
 846     lispobj code, new;
 847
 848     /* Find the corresponding code object. */
 849     code = thing - HeaderValue(header)*sizeof(lispobj);
 850
 851     /* Make sure it's been transported. */
 852     new = *(lispobj *)native_pointer(code);
 853     if (!forwarding_pointer_p(new))
 854         new = ptrans_code(code);
 855
 856     /* Maintain the offset: */
 857     return new + (thing - code);
 858 }
 859
 860 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 861
 862 static lispobj
 863 ptrans_list(lispobj thing, boolean constant)
 864 {
 865     struct cons *old, *new, *orig;
 866     int length;
 867
 868     if (constant)
 869         orig = (struct cons *)read_only_free;
 870     else
 871         orig = (struct cons *)static_free;
 872     length = 0;
 873
 874     do {
 875         /* Allocate a new cons cell. */
 876         old = (struct cons *)native_pointer(thing);
 877         if (constant) {
 878             new = (struct cons *)read_only_free;
 879             read_only_free += WORDS_PER_CONS;
 880         }
 881         else {
 882             new = (struct cons *)static_free;
 883             static_free += WORDS_PER_CONS;
 884         }
 885
 886         /* Copy the cons cell and keep a pointer to the cdr. */
 887         new->car = old->car;
 888         thing = new->cdr = old->cdr;
 889
 890         /* Set up the forwarding pointer. */
 891         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 892
 893         /* And count this cell. */
 894         length++;
 895     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 896              dynamic_pointer_p(thing) &&
 897              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 898
 899     /* Scavenge the list we just copied. */
 900     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 901
 902     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 903 }
 904
 905 static lispobj
 906 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 907 {
 908     switch (widetag_of(header)) {
 909         /* FIXME: this needs a reindent */
 910       case BIGNUM_WIDETAG:
 911       case SINGLE_FLOAT_WIDETAG:
 912       case DOUBLE_FLOAT_WIDETAG:
 913 #ifdef LONG_FLOAT_WIDETAG
 914       case LONG_FLOAT_WIDETAG:
 915 #endif
 916 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 917       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 918 #endif
 919 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 920       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 921 #endif
 922 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 923       case COMPLEX_LONG_FLOAT_WIDETAG:
 924 #endif
 925       case SAP_WIDETAG:
 926           return ptrans_unboxed(thing, header);
 927
 928       case RATIO_WIDETAG:
 929       case COMPLEX_WIDETAG:
 930       case SIMPLE_ARRAY_WIDETAG:
 931       case COMPLEX_BASE_STRING_WIDETAG:
 932       case COMPLEX_BIT_VECTOR_WIDETAG:
 933       case COMPLEX_VECTOR_NIL_WIDETAG:
 934       case COMPLEX_VECTOR_WIDETAG:
 935       case COMPLEX_ARRAY_WIDETAG:
 936         return ptrans_boxed(thing, header, constant);
 937
 938       case VALUE_CELL_HEADER_WIDETAG:
 939       case WEAK_POINTER_WIDETAG:
 940         return ptrans_boxed(thing, header, 0);
 941
 942       case SYMBOL_HEADER_WIDETAG:
 943         return ptrans_boxed(thing, header, 0);
 944
 945       case SIMPLE_ARRAY_NIL_WIDETAG:
 946         return ptrans_vector(thing, 0, 0, 0, constant);
 947
 948       case SIMPLE_BASE_STRING_WIDETAG:
 949         return ptrans_vector(thing, 8, 1, 0, constant);
 950
 951       case SIMPLE_BIT_VECTOR_WIDETAG:
 952         return ptrans_vector(thing, 1, 0, 0, constant);
 953
 954       case SIMPLE_VECTOR_WIDETAG:
 955         return ptrans_vector(thing, 32, 0, 1, constant);
 956
 957       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 958         return ptrans_vector(thing, 2, 0, 0, constant);
 959
 960       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 961         return ptrans_vector(thing, 4, 0, 0, constant);
 962
 963       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 964 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 965       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 966       case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 967 #endif
 968         return ptrans_vector(thing, 8, 0, 0, constant);
 969
 970       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 971 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 972       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 973       case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 974 #endif
 975         return ptrans_vector(thing, 16, 0, 0, constant);
 976
 977       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 978 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 979       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 980       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 981 #endif
 982 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 983       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 984       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 985 #endif
 986         return ptrans_vector(thing, 32, 0, 0, constant);
 987
 988       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 989         return ptrans_vector(thing, 32, 0, 0, constant);
 990
 991       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 992         return ptrans_vector(thing, 64, 0, 0, constant);
 993
 994 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 995       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 996 #ifdef __i386__
 997         return ptrans_vector(thing, 96, 0, 0, constant);
 998 #endif
 999 #ifdef sparc
1000         return ptrans_vector(thing, 128, 0, 0, constant);
1001 #endif
1002 #endif
1003
1004 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1005       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1006         return ptrans_vector(thing, 64, 0, 0, constant);
1007 #endif
1008
1009 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1010       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1011         return ptrans_vector(thing, 128, 0, 0, constant);
1012 #endif
1013
1014 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1015       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1016 #ifdef __i386__
1017         return ptrans_vector(thing, 192, 0, 0, constant);
1018 #endif
1019 #ifdef sparc
1020         return ptrans_vector(thing, 256, 0, 0, constant);
1021 #endif
1022 #endif
1023
1024       case CODE_HEADER_WIDETAG:
1025         return ptrans_code(thing);
1026
1027       case RETURN_PC_HEADER_WIDETAG:
1028         return ptrans_returnpc(thing, header);
1029
1030       case FDEFN_WIDETAG:
1031         return ptrans_fdefn(thing, header);
1032
1033       default:
1034         /* Should only come across other pointers to the above stuff. */
1035         gc_abort();
1036         return NIL;
1037     }
1038 }
1039
1040 static int
1041 pscav_fdefn(struct fdefn *fdefn)
1042 {
1043     boolean fix_func;
1044
1045     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
1046     pscav(&fdefn->name, 1, 1);
1047     pscav(&fdefn->fun, 1, 0);
1048     if (fix_func)
1049         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
1050     return sizeof(struct fdefn) / sizeof(lispobj);
1051 }
1052
1053 #ifdef __i386__
1054 /* now putting code objects in static space */
1055 static int
1056 pscav_code(struct code*code)
1057 {
1058     int nwords;
1059     lispobj func;
1060     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
1061
1062     /* Arrange to scavenge the debug info later. */
1063     pscav_later(&code->debug_info, 1);
1064
1065     /* Scavenge the constants. */
1066     pscav(code->constants, HeaderValue(code->header)-5, 1);
1067
1068     /* Scavenge all the functions. */
1069     pscav(&code->entry_points, 1, 1);
1070     for (func = code->entry_points;
1071          func != NIL;
1072          func = ((struct simple_fun *)native_pointer(func))->next) {
1073         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
1074         gc_assert(!dynamic_pointer_p(func));
1075
1076 #ifdef __i386__
1077         /* Temporarily convert the self pointer to a real function
1078          * pointer. */
1079         ((struct simple_fun *)native_pointer(func))->self
1080             -= FUN_RAW_ADDR_OFFSET;
1081 #endif
1082         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
1083 #ifdef __i386__
1084         ((struct simple_fun *)native_pointer(func))->self
1085             += FUN_RAW_ADDR_OFFSET;
1086 #endif
1087         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
1088     }
1089
1090     return CEILING(nwords,2);
1091 }
1092 #endif
1093
1094 static lispobj *
1095 pscav(lispobj *addr, int nwords, boolean constant)
1096 {
1097     lispobj thing, *thingp, header;
1098     int count = 0; /* (0 = dummy init value to stop GCC warning) */
1099     struct vector *vector;
1100
1101     while (nwords > 0) {
1102         thing = *addr;
1103         if (is_lisp_pointer(thing)) {
1104             /* It's a pointer. Is it something we might have to move? */
1105             if (dynamic_pointer_p(thing)) {
1106                 /* Maybe. Have we already moved it? */
1107                 thingp = (lispobj *)native_pointer(thing);
1108                 header = *thingp;
1109                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
1110                     /* Yep, so just copy the forwarding pointer. */
1111                     thing = header;
1112                 else {
1113                     /* Nope, copy the object. */
1114                     switch (lowtag_of(thing)) {
1115                       case FUN_POINTER_LOWTAG:
1116                         thing = ptrans_func(thing, header);
1117                         break;
1118
1119                       case LIST_POINTER_LOWTAG:
1120                         thing = ptrans_list(thing, constant);
1121                         break;
1122
1123                       case INSTANCE_POINTER_LOWTAG:
1124                         thing = ptrans_instance(thing, header, constant);
1125                         break;
1126
1127                       case OTHER_POINTER_LOWTAG:
1128                         thing = ptrans_otherptr(thing, header, constant);
1129                         break;
1130
1131                       default:
1132                         /* It was a pointer, but not one of them? */
1133                         gc_abort();
1134                     }
1135                 }
1136                 *addr = thing;
1137             }
1138             count = 1;
1139         }
1140         else if (thing & 3) {
1141             /* It's an other immediate. Maybe the header for an unboxed */
1142             /* object. */
1143             switch (widetag_of(thing)) {
1144               case BIGNUM_WIDETAG:
1145               case SINGLE_FLOAT_WIDETAG:
1146               case DOUBLE_FLOAT_WIDETAG:
1147 #ifdef LONG_FLOAT_WIDETAG
1148               case LONG_FLOAT_WIDETAG:
1149 #endif
1150               case SAP_WIDETAG:
1151                 /* It's an unboxed simple object. */
1152                 count = HeaderValue(thing)+1;
1153                 break;
1154
1155               case SIMPLE_VECTOR_WIDETAG:
1156                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
1157                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
1158                         SIMPLE_VECTOR_WIDETAG;
1159                   }
1160                 count = 1;
1161                 break;
1162
1163               case SIMPLE_ARRAY_NIL_WIDETAG:
1164                 count = 2;
1165                 break;
1166
1167               case SIMPLE_BASE_STRING_WIDETAG:
1168                 vector = (struct vector *)addr;
1169                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,4)+2,2);
1170                 break;
1171
1172               case SIMPLE_BIT_VECTOR_WIDETAG:
1173                 vector = (struct vector *)addr;
1174                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
1175                 break;
1176
1177               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1178                 vector = (struct vector *)addr;
1179                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
1180                 break;
1181
1182               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1183                 vector = (struct vector *)addr;
1184                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
1185                 break;
1186
1187               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1188 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1189               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1190               case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
1191 #endif
1192                 vector = (struct vector *)addr;
1193                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
1194                 break;
1195
1196               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1197 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1198               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1199               case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
1200 #endif
1201                 vector = (struct vector *)addr;
1202                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
1203                 break;
1204
1205               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1206 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1207               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1208               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
1209 #endif
1210 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1211               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1212               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
1213 #endif
1214                 vector = (struct vector *)addr;
1215                 count = CEILING(fixnum_value(vector->length)+2,2);
1216                 break;
1217
1218               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1219                 vector = (struct vector *)addr;
1220                 count = CEILING(fixnum_value(vector->length)+2,2);
1221                 break;
1222
1223               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1224 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1225               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1226 #endif
1227                 vector = (struct vector *)addr;
1228                 count = fixnum_value(vector->length)*2+2;
1229                 break;
1230
1231 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1232               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1233                 vector = (struct vector *)addr;
1234 #ifdef __i386__
1235                 count = fixnum_value(vector->length)*3+2;
1236 #endif
1237 #ifdef sparc
1238                 count = fixnum_value(vector->length)*4+2;
1239 #endif
1240                 break;
1241 #endif
1242
1243 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1244               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1245                 vector = (struct vector *)addr;
1246                 count = fixnum_value(vector->length)*4+2;
1247                 break;
1248 #endif
1249
1250 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1251               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1252                 vector = (struct vector *)addr;
1253 #ifdef __i386__
1254                 count = fixnum_value(vector->length)*6+2;
1255 #endif
1256 #ifdef sparc
1257                 count = fixnum_value(vector->length)*8+2;
1258 #endif
1259                 break;
1260 #endif
1261
1262               case CODE_HEADER_WIDETAG:
1263 #ifndef __i386__
1264                 gc_abort(); /* no code headers in static space */
1265 #else
1266                 count = pscav_code((struct code*)addr);
1267 #endif
1268                 break;
1269
1270               case SIMPLE_FUN_HEADER_WIDETAG:
1271               case CLOSURE_FUN_HEADER_WIDETAG:
1272               case RETURN_PC_HEADER_WIDETAG:
1273                 /* We should never hit any of these, 'cause they occur
1274                  * buried in the middle of code objects. */
1275                 gc_abort();
1276                 break;
1277
1278 #ifdef __i386__
1279               case CLOSURE_HEADER_WIDETAG:
1280               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
1281                 /* The function self pointer needs special care on the
1282                  * x86 because it is the real entry point. */
1283                 {
1284                   lispobj fun = ((struct closure *)addr)->fun
1285                     - FUN_RAW_ADDR_OFFSET;
1286                   pscav(&fun, 1, constant);
1287                   ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
1288                 }
1289                 count = 2;
1290                 break;
1291 #endif
1292
1293               case WEAK_POINTER_WIDETAG:
1294                 /* Weak pointers get preserved during purify, 'cause I
1295                  * don't feel like figuring out how to break them. */
1296                 pscav(addr+1, 2, constant);
1297                 count = 4;
1298                 break;
1299
1300               case FDEFN_WIDETAG:
1301                 /* We have to handle fdefn objects specially, so we
1302                  * can fix up the raw function address. */
1303                 count = pscav_fdefn((struct fdefn *)addr);
1304                 break;
1305
1306               default:
1307                 count = 1;
1308                 break;
1309             }
1310         }
1311         else {
1312             /* It's a fixnum. */
1313             count = 1;
1314         }
1315
1316         addr += count;
1317         nwords -= count;
1318     }
1319
1320     return addr;
1321 }
1322
1323 int
1324 purify(lispobj static_roots, lispobj read_only_roots)
1325 {
1326     lispobj *clean;
1327     int count, i;
1328     struct later *laters, *next;
1329     struct thread *thread;
1330
1331 #ifdef PRINTNOISE
1332     printf("[doing purification:");
1333     fflush(stdout);
1334 #endif
1335 #ifdef LISP_FEATURE_GENCGC
1336     gc_alloc_update_all_page_tables();
1337 #endif
1338     for_each_thread(thread)
1339         if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)) != 0) {
1340         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
1341          * its error simply by a. printing a string b. to stdout instead
1342          * of stderr. */
1343         printf(" Ack! Can't purify interrupt contexts. ");
1344         fflush(stdout);
1345         return 0;
1346     }
1347
1348 #if defined(__i386__)
1349     dynamic_space_free_pointer =
1350       (lispobj*)SymbolValue(ALLOCATION_POINTER,0);
1351 #endif
1352
1353     read_only_end = read_only_free =
1354         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
1355     static_end = static_free =
1356         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
1357
1358 #ifdef PRINTNOISE
1359     printf(" roots");
1360     fflush(stdout);
1361 #endif
1362
1363 #if (defined(LISP_FEATURE_GENCGC) && defined(LISP_FEATURE_X86))
1364 #if 0
1365     /* This is what we should do, but can't unless the threads in
1366      * question are suspended with ptrace.  That's right, purify is not
1367      * threadsafe
1368      */
1369     for_each_thread(thread) {
1370         void **ptr;
1371         struct user_regs_struct regs;
1372         if(ptrace(PTRACE_GETREGS,thread->pid,0,&regs)){
1373             fprintf(stderr,"child pid %d, %s\n",thread->pid,strerror(errno));
1374             lose("PTRACE_GETREGS");
1375         }
1376         setup_i386_stack_scav(regs.ebp,
1377                               ((void *)thread->control_stack_end));
1378     }
1379 #endif /* 0 */
1380     /* stopgap until we can set things up as in preceding comment */
1381     setup_i386_stack_scav(((&static_roots)-2),
1382                           ((void *)all_threads->control_stack_end));
1383 #endif
1384
1385     pscav(&static_roots, 1, 0);
1386     pscav(&read_only_roots, 1, 1);
1387
1388 #ifdef PRINTNOISE
1389     printf(" handlers");
1390     fflush(stdout);
1391 #endif
1392     pscav((lispobj *) all_threads->interrupt_data->interrupt_handlers,
1393           sizeof(all_threads->interrupt_data->interrupt_handlers)
1394           / sizeof(lispobj),
1395           0);
1396
1397 #ifdef PRINTNOISE
1398     printf(" stack");
1399     fflush(stdout);
1400 #endif
1401 #ifndef __i386__
1402     pscav((lispobj *)all_threads->control_stack_start,
1403           current_control_stack_pointer -
1404           all_threads->control_stack_start,
1405           0);
1406 #else
1407 #ifdef LISP_FEATURE_GENCGC
1408     pscav_i386_stack();
1409 #endif
1410 #endif
1411
1412 #ifdef PRINTNOISE
1413     printf(" bindings");
1414     fflush(stdout);
1415 #endif
1416 #if !defined(__i386__)
1417     pscav( (lispobj *)all_threads->binding_stack_start,
1418           (lispobj *)current_binding_stack_pointer -
1419            all_threads->binding_stack_start,
1420           0);
1421 #else
1422     for_each_thread(thread) {
1423         pscav( (lispobj *)thread->binding_stack_start,
1424                (lispobj *)SymbolValue(BINDING_STACK_POINTER,thread) -
1425                (lispobj *)thread->binding_stack_start,
1426           0);
1427         pscav( (lispobj *) (thread+1),
1428                fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
1429                (sizeof (struct thread))/(sizeof (lispobj)),
1430           0);
1431     }
1432
1433
1434 #endif
1435
1436     /* The original CMU CL code had scavenge-read-only-space code
1437      * controlled by the Lisp-level variable
1438      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
1439      * wasn't documented under what circumstances it was useful or
1440      * safe to turn it on, so it's been turned off in SBCL. If you
1441      * want/need this functionality, and can test and document it,
1442      * please submit a patch. */
1443 #if 0
1444     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
1445         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
1446       unsigned  read_only_space_size =
1447           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
1448           (lispobj *)READ_ONLY_SPACE_START;
1449       fprintf(stderr,
1450               "scavenging read only space: %d bytes\n",
1451               read_only_space_size * sizeof(lispobj));
1452       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
1453     }
1454 #endif
1455
1456 #ifdef PRINTNOISE
1457     printf(" static");
1458     fflush(stdout);
1459 #endif
1460     clean = (lispobj *)STATIC_SPACE_START;
1461     do {
1462         while (clean != static_free)
1463             clean = pscav(clean, static_free - clean, 0);
1464         laters = later_blocks;
1465         count = later_count;
1466         later_blocks = NULL;
1467         later_count = 0;
1468         while (laters != NULL) {
1469             for (i = 0; i < count; i++) {
1470                 if (laters->u[i].count == 0) {
1471                     ;
1472                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1473                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1474                     i++;
1475                 } else {
1476                     pscav(laters->u[i].ptr, 1, 1);
1477                 }
1478             }
1479             next = laters->next;
1480             free(laters);
1481             laters = next;
1482             count = LATERBLOCKSIZE;
1483         }
1484     } while (clean != static_free || later_blocks != NULL);
1485
1486 #ifdef PRINTNOISE
1487     printf(" cleanup");
1488     fflush(stdout);
1489 #endif
1490
1491     os_zero((os_vm_address_t) current_dynamic_space,
1492             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
1493
1494     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
1495      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
1496 #ifndef __i386__
1497     os_zero((os_vm_address_t) current_control_stack_pointer,
1498             (os_vm_size_t)
1499             ((all_threads->control_stack_end -
1500               current_control_stack_pointer) * sizeof(lispobj)));
1501 #endif
1502
1503     /* It helps to update the heap free pointers so that free_heap can
1504      * verify after it's done. */
1505     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free,0);
1506     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free,0);
1507
1508 #if !defined(__i386__)
1509     dynamic_space_free_pointer = current_dynamic_space;
1510     set_auto_gc_trigger(bytes_consed_between_gcs);
1511 #else
1512 #if defined LISP_FEATURE_GENCGC
1513     gc_free_heap();
1514 #else
1515 #error unsupported case /* in CMU CL, was "ibmrt using GC" */
1516 #endif
1517 #endif
1518
1519 #ifdef PRINTNOISE
1520     printf(" done]\n");
1521     fflush(stdout);
1522 #endif
1523     return 0;
1524 }