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(LISP_FEATURE_X86)
  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 LISP_FEATURE_X86
 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 LISP_FEATURE_X86
 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 LISP_FEATURE_X86
 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 LISP_FEATURE_X86
 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 LISP_FEATURE_X86
 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
 792         /* We can only end up here if the code object has not been
 793          * scavenged, because if it had been scavenged, forwarding pointers
 794          * would have been left behind for all the entry points. */
 795
 796         function = (struct simple_fun *)native_pointer(thing);
 797         code =
 798             make_lispobj
 799             ((native_pointer(thing) -
 800               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 801
 802         /* This will cause the function's header to be replaced with a
 803          * forwarding pointer. */
 804
 805         ptrans_code(code);
 806
 807         /* So we can just return that. */
 808         return function->header;
 809     }
 810     else {
 811         /* It's some kind of closure-like thing. */
 812         nwords = 1 + HeaderValue(header);
 813         old = (lispobj *)native_pointer(thing);
 814
 815         /* Allocate the new one. */
 816         if (widetag_of(header) == FUNCALLABLE_INSTANCE_HEADER_WIDETAG) {
 817             /* FINs *must* not go in read_only space. */
 818             new = static_free;
 819             static_free += CEILING(nwords, 2);
 820         }
 821         else {
 822             /* Closures can always go in read-only space, 'cause they
 823              * never change. */
 824
 825             new = read_only_free;
 826             read_only_free += CEILING(nwords, 2);
 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     if (constant)
 868         orig = (struct cons *)read_only_free;
 869     else
 870         orig = (struct cons *)static_free;
 871     length = 0;
 872
 873     do {
 874         /* Allocate a new cons cell. */
 875         old = (struct cons *)native_pointer(thing);
 876         if (constant) {
 877             new = (struct cons *)read_only_free;
 878             read_only_free += WORDS_PER_CONS;
 879         }
 880         else {
 881             new = (struct cons *)static_free;
 882             static_free += WORDS_PER_CONS;
 883         }
 884
 885         /* Copy the cons cell and keep a pointer to the cdr. */
 886         new->car = old->car;
 887         thing = new->cdr = old->cdr;
 888
 889         /* Set up the forwarding pointer. */
 890         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 891
 892         /* And count this cell. */
 893         length++;
 894     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 895              dynamic_pointer_p(thing) &&
 896              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 897
 898     /* Scavenge the list we just copied. */
 899     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 900
 901     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 902 }
 903
 904 static lispobj
 905 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 906 {
 907     switch (widetag_of(header)) {
 908         /* FIXME: this needs a reindent */
 909       case BIGNUM_WIDETAG:
 910       case SINGLE_FLOAT_WIDETAG:
 911       case DOUBLE_FLOAT_WIDETAG:
 912 #ifdef LONG_FLOAT_WIDETAG
 913       case LONG_FLOAT_WIDETAG:
 914 #endif
 915 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 916       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 917 #endif
 918 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 919       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 920 #endif
 921 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 922       case COMPLEX_LONG_FLOAT_WIDETAG:
 923 #endif
 924       case SAP_WIDETAG:
 925           return ptrans_unboxed(thing, header);
 926
 927       case RATIO_WIDETAG:
 928       case COMPLEX_WIDETAG:
 929       case SIMPLE_ARRAY_WIDETAG:
 930       case COMPLEX_BASE_STRING_WIDETAG:
 931       case COMPLEX_BIT_VECTOR_WIDETAG:
 932       case COMPLEX_VECTOR_NIL_WIDETAG:
 933       case COMPLEX_VECTOR_WIDETAG:
 934       case COMPLEX_ARRAY_WIDETAG:
 935         return ptrans_boxed(thing, header, constant);
 936
 937       case VALUE_CELL_HEADER_WIDETAG:
 938       case WEAK_POINTER_WIDETAG:
 939         return ptrans_boxed(thing, header, 0);
 940
 941       case SYMBOL_HEADER_WIDETAG:
 942         return ptrans_boxed(thing, header, 0);
 943
 944       case SIMPLE_ARRAY_NIL_WIDETAG:
 945         return ptrans_vector(thing, 0, 0, 0, constant);
 946
 947       case SIMPLE_BASE_STRING_WIDETAG:
 948         return ptrans_vector(thing, 8, 1, 0, constant);
 949
 950       case SIMPLE_BIT_VECTOR_WIDETAG:
 951         return ptrans_vector(thing, 1, 0, 0, constant);
 952
 953       case SIMPLE_VECTOR_WIDETAG:
 954         return ptrans_vector(thing, 32, 0, 1, constant);
 955
 956       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 957         return ptrans_vector(thing, 2, 0, 0, constant);
 958
 959       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 960         return ptrans_vector(thing, 4, 0, 0, constant);
 961
 962       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 963 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 964       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 965       case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
 966 #endif
 967         return ptrans_vector(thing, 8, 0, 0, constant);
 968
 969       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 970 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 971       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 972       case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
 973 #endif
 974         return ptrans_vector(thing, 16, 0, 0, constant);
 975
 976       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 977 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 978       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 979       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
 980 #endif
 981 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 982       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 983       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
 984 #endif
 985         return ptrans_vector(thing, 32, 0, 0, constant);
 986
 987       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 988         return ptrans_vector(thing, 32, 0, 0, constant);
 989
 990       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 991         return ptrans_vector(thing, 64, 0, 0, constant);
 992
 993 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 994       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 995 #ifdef LISP_FEATURE_X86
 996         return ptrans_vector(thing, 96, 0, 0, constant);
 997 #endif
 998 #ifdef sparc
 999         return ptrans_vector(thing, 128, 0, 0, constant);
1000 #endif
1001 #endif
1002
1003 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1004       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1005         return ptrans_vector(thing, 64, 0, 0, constant);
1006 #endif
1007
1008 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1009       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1010         return ptrans_vector(thing, 128, 0, 0, constant);
1011 #endif
1012
1013 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1014       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1015 #ifdef LISP_FEATURE_X86
1016         return ptrans_vector(thing, 192, 0, 0, constant);
1017 #endif
1018 #ifdef sparc
1019         return ptrans_vector(thing, 256, 0, 0, constant);
1020 #endif
1021 #endif
1022
1023       case CODE_HEADER_WIDETAG:
1024         return ptrans_code(thing);
1025
1026       case RETURN_PC_HEADER_WIDETAG:
1027         return ptrans_returnpc(thing, header);
1028
1029       case FDEFN_WIDETAG:
1030         return ptrans_fdefn(thing, header);
1031
1032       default:
1033         /* Should only come across other pointers to the above stuff. */
1034         gc_abort();
1035         return NIL;
1036     }
1037 }
1038
1039 static int
1040 pscav_fdefn(struct fdefn *fdefn)
1041 {
1042     boolean fix_func;
1043
1044     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
1045     pscav(&fdefn->name, 1, 1);
1046     pscav(&fdefn->fun, 1, 0);
1047     if (fix_func)
1048         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
1049     return sizeof(struct fdefn) / sizeof(lispobj);
1050 }
1051
1052 #ifdef LISP_FEATURE_X86
1053 /* now putting code objects in static space */
1054 static int
1055 pscav_code(struct code*code)
1056 {
1057     int nwords;
1058     lispobj func;
1059     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
1060
1061     /* Arrange to scavenge the debug info later. */
1062     pscav_later(&code->debug_info, 1);
1063
1064     /* Scavenge the constants. */
1065     pscav(code->constants, HeaderValue(code->header)-5, 1);
1066
1067     /* Scavenge all the functions. */
1068     pscav(&code->entry_points, 1, 1);
1069     for (func = code->entry_points;
1070          func != NIL;
1071          func = ((struct simple_fun *)native_pointer(func))->next) {
1072         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
1073         gc_assert(!dynamic_pointer_p(func));
1074
1075 #ifdef LISP_FEATURE_X86
1076         /* Temporarily convert the self pointer to a real function
1077          * pointer. */
1078         ((struct simple_fun *)native_pointer(func))->self
1079             -= FUN_RAW_ADDR_OFFSET;
1080 #endif
1081         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
1082 #ifdef LISP_FEATURE_X86
1083         ((struct simple_fun *)native_pointer(func))->self
1084             += FUN_RAW_ADDR_OFFSET;
1085 #endif
1086         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
1087     }
1088
1089     return CEILING(nwords,2);
1090 }
1091 #endif
1092
1093 static lispobj *
1094 pscav(lispobj *addr, int nwords, boolean constant)
1095 {
1096     lispobj thing, *thingp, header;
1097     int count = 0; /* (0 = dummy init value to stop GCC warning) */
1098     struct vector *vector;
1099
1100     while (nwords > 0) {
1101         thing = *addr;
1102         if (is_lisp_pointer(thing)) {
1103             /* It's a pointer. Is it something we might have to move? */
1104             if (dynamic_pointer_p(thing)) {
1105                 /* Maybe. Have we already moved it? */
1106                 thingp = (lispobj *)native_pointer(thing);
1107                 header = *thingp;
1108                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
1109                     /* Yep, so just copy the forwarding pointer. */
1110                     thing = header;
1111                 else {
1112                     /* Nope, copy the object. */
1113                     switch (lowtag_of(thing)) {
1114                       case FUN_POINTER_LOWTAG:
1115                         thing = ptrans_func(thing, header);
1116                         break;
1117
1118                       case LIST_POINTER_LOWTAG:
1119                         thing = ptrans_list(thing, constant);
1120                         break;
1121
1122                       case INSTANCE_POINTER_LOWTAG:
1123                         thing = ptrans_instance(thing, header, constant);
1124                         break;
1125
1126                       case OTHER_POINTER_LOWTAG:
1127                         thing = ptrans_otherptr(thing, header, constant);
1128                         break;
1129
1130                       default:
1131                         /* It was a pointer, but not one of them? */
1132                         gc_abort();
1133                     }
1134                 }
1135                 *addr = thing;
1136             }
1137             count = 1;
1138         }
1139         else if (thing & 3) {
1140             /* It's an other immediate. Maybe the header for an unboxed */
1141             /* object. */
1142             switch (widetag_of(thing)) {
1143               case BIGNUM_WIDETAG:
1144               case SINGLE_FLOAT_WIDETAG:
1145               case DOUBLE_FLOAT_WIDETAG:
1146 #ifdef LONG_FLOAT_WIDETAG
1147               case LONG_FLOAT_WIDETAG:
1148 #endif
1149               case SAP_WIDETAG:
1150                 /* It's an unboxed simple object. */
1151                 count = HeaderValue(thing)+1;
1152                 break;
1153
1154               case SIMPLE_VECTOR_WIDETAG:
1155                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
1156                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
1157                         SIMPLE_VECTOR_WIDETAG;
1158                   }
1159                 count = 1;
1160                 break;
1161
1162               case SIMPLE_ARRAY_NIL_WIDETAG:
1163                 count = 2;
1164                 break;
1165
1166               case SIMPLE_BASE_STRING_WIDETAG:
1167                 vector = (struct vector *)addr;
1168                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,4)+2,2);
1169                 break;
1170
1171               case SIMPLE_BIT_VECTOR_WIDETAG:
1172                 vector = (struct vector *)addr;
1173                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
1174                 break;
1175
1176               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1177                 vector = (struct vector *)addr;
1178                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
1179                 break;
1180
1181               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1182                 vector = (struct vector *)addr;
1183                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
1184                 break;
1185
1186               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1187 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1188               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1189               case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
1190 #endif
1191                 vector = (struct vector *)addr;
1192                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
1193                 break;
1194
1195               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1196 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1197               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1198               case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
1199 #endif
1200                 vector = (struct vector *)addr;
1201                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
1202                 break;
1203
1204               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1205 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1206               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1207               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
1208 #endif
1209 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1210               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1211               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
1212 #endif
1213                 vector = (struct vector *)addr;
1214                 count = CEILING(fixnum_value(vector->length)+2,2);
1215                 break;
1216
1217               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1218                 vector = (struct vector *)addr;
1219                 count = CEILING(fixnum_value(vector->length)+2,2);
1220                 break;
1221
1222               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1223 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1224               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1225 #endif
1226                 vector = (struct vector *)addr;
1227                 count = fixnum_value(vector->length)*2+2;
1228                 break;
1229
1230 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1231               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1232                 vector = (struct vector *)addr;
1233 #ifdef LISP_FEATURE_X86
1234                 count = fixnum_value(vector->length)*3+2;
1235 #endif
1236 #ifdef sparc
1237                 count = fixnum_value(vector->length)*4+2;
1238 #endif
1239                 break;
1240 #endif
1241
1242 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1243               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1244                 vector = (struct vector *)addr;
1245                 count = fixnum_value(vector->length)*4+2;
1246                 break;
1247 #endif
1248
1249 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1250               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1251                 vector = (struct vector *)addr;
1252 #ifdef LISP_FEATURE_X86
1253                 count = fixnum_value(vector->length)*6+2;
1254 #endif
1255 #ifdef sparc
1256                 count = fixnum_value(vector->length)*8+2;
1257 #endif
1258                 break;
1259 #endif
1260
1261               case CODE_HEADER_WIDETAG:
1262 #ifndef LISP_FEATURE_X86
1263                 gc_abort(); /* no code headers in static space */
1264 #else
1265                 count = pscav_code((struct code*)addr);
1266 #endif
1267                 break;
1268
1269               case SIMPLE_FUN_HEADER_WIDETAG:
1270               case RETURN_PC_HEADER_WIDETAG:
1271                 /* We should never hit any of these, 'cause they occur
1272                  * buried in the middle of code objects. */
1273                 gc_abort();
1274                 break;
1275
1276 #ifdef LISP_FEATURE_X86
1277               case CLOSURE_HEADER_WIDETAG:
1278               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
1279                 /* The function self pointer needs special care on the
1280                  * x86 because it is the real entry point. */
1281                 {
1282                   lispobj fun = ((struct closure *)addr)->fun
1283                     - FUN_RAW_ADDR_OFFSET;
1284                   pscav(&fun, 1, constant);
1285                   ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
1286                 }
1287                 count = 2;
1288                 break;
1289 #endif
1290
1291               case WEAK_POINTER_WIDETAG:
1292                 /* Weak pointers get preserved during purify, 'cause I
1293                  * don't feel like figuring out how to break them. */
1294                 pscav(addr+1, 2, constant);
1295                 count = 4;
1296                 break;
1297
1298               case FDEFN_WIDETAG:
1299                 /* We have to handle fdefn objects specially, so we
1300                  * can fix up the raw function address. */
1301                 count = pscav_fdefn((struct fdefn *)addr);
1302                 break;
1303
1304               default:
1305                 count = 1;
1306                 break;
1307             }
1308         }
1309         else {
1310             /* It's a fixnum. */
1311             count = 1;
1312         }
1313
1314         addr += count;
1315         nwords -= count;
1316     }
1317
1318     return addr;
1319 }
1320
1321 int
1322 purify(lispobj static_roots, lispobj read_only_roots)
1323 {
1324     lispobj *clean;
1325     int count, i;
1326     struct later *laters, *next;
1327     struct thread *thread;
1328
1329 #ifdef PRINTNOISE
1330     printf("[doing purification:");
1331     fflush(stdout);
1332 #endif
1333 #ifdef LISP_FEATURE_GENCGC
1334     gc_alloc_update_all_page_tables();
1335 #endif
1336     for_each_thread(thread)
1337         if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)) != 0) {
1338         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
1339          * its error simply by a. printing a string b. to stdout instead
1340          * of stderr. */
1341         printf(" Ack! Can't purify interrupt contexts. ");
1342         fflush(stdout);
1343         return 0;
1344     }
1345
1346 #if defined(LISP_FEATURE_X86)
1347     dynamic_space_free_pointer =
1348       (lispobj*)SymbolValue(ALLOCATION_POINTER,0);
1349 #endif
1350
1351     read_only_end = read_only_free =
1352         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
1353     static_end = static_free =
1354         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
1355
1356 #ifdef PRINTNOISE
1357     printf(" roots");
1358     fflush(stdout);
1359 #endif
1360
1361 #if (defined(LISP_FEATURE_GENCGC) && defined(LISP_FEATURE_X86))
1362 #if 0
1363     /* This is what we should do, but can't unless the threads in
1364      * question are suspended with ptrace.  That's right, purify is not
1365      * threadsafe
1366      */
1367     for_each_thread(thread) {
1368         void **ptr;
1369         struct user_regs_struct regs;
1370         if(ptrace(PTRACE_GETREGS,thread->pid,0,&regs)){
1371             fprintf(stderr,"child pid %d, %s\n",thread->pid,strerror(errno));
1372             lose("PTRACE_GETREGS");
1373         }
1374         setup_i386_stack_scav(regs.ebp,
1375                               ((void *)thread->control_stack_end));
1376     }
1377 #endif /* 0 */
1378     /* stopgap until we can set things up as in preceding comment */
1379     setup_i386_stack_scav(((&static_roots)-2),
1380                           ((void *)all_threads->control_stack_end));
1381 #endif
1382
1383     pscav(&static_roots, 1, 0);
1384     pscav(&read_only_roots, 1, 1);
1385
1386 #ifdef PRINTNOISE
1387     printf(" handlers");
1388     fflush(stdout);
1389 #endif
1390     pscav((lispobj *) all_threads->interrupt_data->interrupt_handlers,
1391           sizeof(all_threads->interrupt_data->interrupt_handlers)
1392           / sizeof(lispobj),
1393           0);
1394
1395 #ifdef PRINTNOISE
1396     printf(" stack");
1397     fflush(stdout);
1398 #endif
1399 #ifndef LISP_FEATURE_X86
1400     pscav((lispobj *)all_threads->control_stack_start,
1401           current_control_stack_pointer -
1402           all_threads->control_stack_start,
1403           0);
1404 #else
1405 #ifdef LISP_FEATURE_GENCGC
1406     pscav_i386_stack();
1407 #endif
1408 #endif
1409
1410 #ifdef PRINTNOISE
1411     printf(" bindings");
1412     fflush(stdout);
1413 #endif
1414 #if !defined(LISP_FEATURE_X86)
1415     pscav( (lispobj *)all_threads->binding_stack_start,
1416           (lispobj *)current_binding_stack_pointer -
1417            all_threads->binding_stack_start,
1418           0);
1419 #else
1420     for_each_thread(thread) {
1421         pscav( (lispobj *)thread->binding_stack_start,
1422                (lispobj *)SymbolValue(BINDING_STACK_POINTER,thread) -
1423                (lispobj *)thread->binding_stack_start,
1424           0);
1425         pscav( (lispobj *) (thread+1),
1426                fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
1427                (sizeof (struct thread))/(sizeof (lispobj)),
1428           0);
1429     }
1430
1431
1432 #endif
1433
1434     /* The original CMU CL code had scavenge-read-only-space code
1435      * controlled by the Lisp-level variable
1436      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
1437      * wasn't documented under what circumstances it was useful or
1438      * safe to turn it on, so it's been turned off in SBCL. If you
1439      * want/need this functionality, and can test and document it,
1440      * please submit a patch. */
1441 #if 0
1442     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
1443         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
1444       unsigned  read_only_space_size =
1445           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
1446           (lispobj *)READ_ONLY_SPACE_START;
1447       fprintf(stderr,
1448               "scavenging read only space: %d bytes\n",
1449               read_only_space_size * sizeof(lispobj));
1450       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
1451     }
1452 #endif
1453
1454 #ifdef PRINTNOISE
1455     printf(" static");
1456     fflush(stdout);
1457 #endif
1458     clean = (lispobj *)STATIC_SPACE_START;
1459     do {
1460         while (clean != static_free)
1461             clean = pscav(clean, static_free - clean, 0);
1462         laters = later_blocks;
1463         count = later_count;
1464         later_blocks = NULL;
1465         later_count = 0;
1466         while (laters != NULL) {
1467             for (i = 0; i < count; i++) {
1468                 if (laters->u[i].count == 0) {
1469                     ;
1470                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1471                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1472                     i++;
1473                 } else {
1474                     pscav(laters->u[i].ptr, 1, 1);
1475                 }
1476             }
1477             next = laters->next;
1478             free(laters);
1479             laters = next;
1480             count = LATERBLOCKSIZE;
1481         }
1482     } while (clean != static_free || later_blocks != NULL);
1483
1484 #ifdef PRINTNOISE
1485     printf(" cleanup");
1486     fflush(stdout);
1487 #endif
1488
1489     os_zero((os_vm_address_t) current_dynamic_space,
1490             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
1491
1492     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
1493      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
1494 #ifndef LISP_FEATURE_X86
1495     os_zero((os_vm_address_t) current_control_stack_pointer,
1496             (os_vm_size_t)
1497             ((all_threads->control_stack_end -
1498               current_control_stack_pointer) * sizeof(lispobj)));
1499 #endif
1500
1501     /* It helps to update the heap free pointers so that free_heap can
1502      * verify after it's done. */
1503     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free,0);
1504     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free,0);
1505
1506 #if !defined(LISP_FEATURE_X86)
1507     dynamic_space_free_pointer = current_dynamic_space;
1508     set_auto_gc_trigger(bytes_consed_between_gcs);
1509 #else
1510 #if defined LISP_FEATURE_GENCGC
1511     gc_free_heap();
1512 #else
1513 #error unsupported case /* in CMU CL, was "ibmrt using GC" */
1514 #endif
1515 #endif
1516
1517 #ifdef PRINTNOISE
1518     printf(" done]\n");
1519     fflush(stdout);
1520 #endif
1521     return 0;
1522 }