src/runtime/purify.c

   1 /*
   2  * C-level stuff to implement Lisp-level PURIFY
   3  */
   4
   5 /*
   6  * This software is part of the SBCL system. See the README file for
   7  * more information.
   8  *
   9  * This software is derived from the CMU CL system, which was
  10  * written at Carnegie Mellon University and released into the
  11  * public domain. The software is in the public domain and is
  12  * provided with absolutely no warranty. See the COPYING and CREDITS
  13  * files for more information.
  14  */
  15
  16 #include <stdio.h>
  17 #include <sys/types.h>
  18 #include <stdlib.h>
  19 #include <strings.h>
  20
  21 #include "runtime.h"
  22 #include "os.h"
  23 #include "sbcl.h"
  24 #include "globals.h"
  25 #include "validate.h"
  26 #include "interrupt.h"
  27 #include "purify.h"
  28 #include "interr.h"
  29 #include "gc.h"
  30 #include "gc-internal.h"
  31 #include "primitive-objects.h"
  32
  33 #define PRINTNOISE
  34
  35 #if defined(__i386__)
  36 /* again, what's so special about the x86 that this is differently
  37  * visible there than on other platforms? -dan 20010125
  38  */
  39 static lispobj *dynamic_space_free_pointer;
  40 #endif
  41
  42 #define gc_abort() \
  43   lose("GC invariant lost, file \"%s\", line %d", __FILE__, __LINE__)
  44
  45 #if 1
  46 #define gc_assert(ex) do { \
  47         if (!(ex)) gc_abort(); \
  48 } while (0)
  49 #else
  50 #define gc_assert(ex)
  51 #endif
  52
  53 \f
  54 /* These hold the original end of the read_only and static spaces so
  55  * we can tell what are forwarding pointers. */
  56
  57 static lispobj *read_only_end, *static_end;
  58
  59 static lispobj *read_only_free, *static_free;
  60
  61 static lispobj *pscav(lispobj *addr, int nwords, boolean constant);
  62
  63 #define LATERBLOCKSIZE 1020
  64 #define LATERMAXCOUNT 10
  65
  66 static struct
  67 later {
  68     struct later *next;
  69     union {
  70         lispobj *ptr;
  71         int count;
  72     } u[LATERBLOCKSIZE];
  73 } *later_blocks = NULL;
  74 static int later_count = 0;
  75
  76 #define CEILING(x,y) (((x) + ((y) - 1)) & (~((y) - 1)))
  77 #define NWORDS(x,y) (CEILING((x),(y)) / (y))
  78
  79 /* FIXME: Shouldn't this be defined in sbcl.h?  See also notes in
  80  * cheneygc.c */
  81
  82 #ifdef sparc
  83 #define FUN_RAW_ADDR_OFFSET 0
  84 #else
  85 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
  86 #endif
  87 \f
  88 static boolean
  89 forwarding_pointer_p(lispobj obj)
  90 {
  91     lispobj *ptr = native_pointer(obj);
  92
  93     return ((static_end <= ptr && ptr <= static_free) ||
  94             (read_only_end <= ptr && ptr <= read_only_free));
  95 }
  96
  97 static boolean
  98 dynamic_pointer_p(lispobj ptr)
  99 {
 100 #ifndef __i386__
 101     return (ptr >= (lispobj)current_dynamic_space
 102             &&
 103             ptr < (lispobj)dynamic_space_free_pointer);
 104 #else
 105     /* Be more conservative, and remember, this is a maybe. */
 106     return (ptr >= (lispobj)DYNAMIC_SPACE_START
 107             &&
 108             ptr < (lispobj)dynamic_space_free_pointer);
 109 #endif
 110 }
 111
 112 \f
 113 #ifdef __i386__
 114
 115 #ifdef LISP_FEATURE_GENCGC
 116 /*
 117  * enhanced x86/GENCGC stack scavenging by Douglas Crosher
 118  *
 119  * Scavenging the stack on the i386 is problematic due to conservative
 120  * roots and raw return addresses. Here it is handled in two passes:
 121  * the first pass runs before any objects are moved and tries to
 122  * identify valid pointers and return address on the stack, the second
 123  * pass scavenges these.
 124  */
 125
 126 static unsigned pointer_filter_verbose = 0;
 127
 128 /* FIXME: This is substantially the same code as in gencgc.c. (There
 129  * are some differences, at least (1) the gencgc.c code needs to worry
 130  * about return addresses on the stack pinning code objects, (2) the
 131  * gencgc.c code needs to worry about the GC maybe happening in an
 132  * interrupt service routine when the main thread of control was
 133  * interrupted just as it had allocated memory and before it
 134  * initialized it, while PURIFY needn't worry about that, and (3) the
 135  * gencgc.c code has mutated more under maintenance since the fork
 136  * from CMU CL than the code here has.) The two versions should be
 137  * made to explicitly share common code, instead of just two different
 138  * cut-and-pasted versions. */
 139 static int
 140 valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
 141 {
 142     /* If it's not a return address then it needs to be a valid Lisp
 143      * pointer. */
 144     if (!is_lisp_pointer((lispobj)pointer))
 145         return 0;
 146
 147     /* Check that the object pointed to is consistent with the pointer
 148      * low tag. */
 149     switch (lowtag_of((lispobj)pointer)) {
 150     case FUN_POINTER_LOWTAG:
 151         /* Start_addr should be the enclosing code object, or a closure
 152          * header. */
 153         switch (widetag_of(*start_addr)) {
 154         case CODE_HEADER_WIDETAG:
 155             /* This case is probably caught above. */
 156             break;
 157         case CLOSURE_HEADER_WIDETAG:
 158         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 159             if ((int)pointer != ((int)start_addr+FUN_POINTER_LOWTAG)) {
 160                 if (pointer_filter_verbose) {
 161                     fprintf(stderr,"*Wf2: %x %x %x\n", (unsigned int) pointer,
 162                             (unsigned int) start_addr, *start_addr);
 163                 }
 164                 return 0;
 165             }
 166             break;
 167         default:
 168             if (pointer_filter_verbose) {
 169                 fprintf(stderr,"*Wf3: %x %x %x\n", (unsigned int) pointer,
 170                         (unsigned int) start_addr, *start_addr);
 171             }
 172             return 0;
 173         }
 174         break;
 175     case LIST_POINTER_LOWTAG:
 176         if ((int)pointer != ((int)start_addr+LIST_POINTER_LOWTAG)) {
 177             if (pointer_filter_verbose)
 178                 fprintf(stderr,"*Wl1: %x %x %x\n", (unsigned int) pointer,
 179                         (unsigned int) start_addr, *start_addr);
 180             return 0;
 181         }
 182         /* Is it plausible cons? */
 183         if ((is_lisp_pointer(start_addr[0])
 184             || ((start_addr[0] & 3) == 0) /* fixnum */
 185             || (widetag_of(start_addr[0]) == BASE_CHAR_WIDETAG)
 186             || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
 187            && (is_lisp_pointer(start_addr[1])
 188                || ((start_addr[1] & 3) == 0) /* fixnum */
 189                || (widetag_of(start_addr[1]) == BASE_CHAR_WIDETAG)
 190                || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
 191             break;
 192         } else {
 193             if (pointer_filter_verbose) {
 194                 fprintf(stderr,"*Wl2: %x %x %x\n", (unsigned int) pointer,
 195                         (unsigned int) start_addr, *start_addr);
 196             }
 197             return 0;
 198         }
 199     case INSTANCE_POINTER_LOWTAG:
 200         if ((int)pointer != ((int)start_addr+INSTANCE_POINTER_LOWTAG)) {
 201             if (pointer_filter_verbose) {
 202                 fprintf(stderr,"*Wi1: %x %x %x\n", (unsigned int) pointer,
 203                         (unsigned int) start_addr, *start_addr);
 204             }
 205             return 0;
 206         }
 207         if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
 208             if (pointer_filter_verbose) {
 209                 fprintf(stderr,"*Wi2: %x %x %x\n", (unsigned int) pointer,
 210                         (unsigned int) start_addr, *start_addr);
 211             }
 212             return 0;
 213         }
 214         break;
 215     case OTHER_POINTER_LOWTAG:
 216         if ((int)pointer != ((int)start_addr+OTHER_POINTER_LOWTAG)) {
 217             if (pointer_filter_verbose) {
 218                 fprintf(stderr,"*Wo1: %x %x %x\n", (unsigned int) pointer,
 219                         (unsigned int) start_addr, *start_addr);
 220             }
 221             return 0;
 222         }
 223         /* Is it plausible? Not a cons. XXX should check the headers. */
 224         if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
 225             if (pointer_filter_verbose) {
 226                 fprintf(stderr,"*Wo2: %x %x %x\n", (unsigned int) pointer,
 227                         (unsigned int) start_addr, *start_addr);
 228             }
 229             return 0;
 230         }
 231         switch (widetag_of(start_addr[0])) {
 232         case UNBOUND_MARKER_WIDETAG:
 233         case BASE_CHAR_WIDETAG:
 234             if (pointer_filter_verbose) {
 235                 fprintf(stderr,"*Wo3: %x %x %x\n", (unsigned int) pointer,
 236                         (unsigned int) start_addr, *start_addr);
 237             }
 238             return 0;
 239
 240             /* only pointed to by function pointers? */
 241         case CLOSURE_HEADER_WIDETAG:
 242         case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
 243             if (pointer_filter_verbose) {
 244                 fprintf(stderr,"*Wo4: %x %x %x\n", (unsigned int) pointer,
 245                         (unsigned int) start_addr, *start_addr);
 246             }
 247             return 0;
 248
 249         case INSTANCE_HEADER_WIDETAG:
 250             if (pointer_filter_verbose) {
 251                 fprintf(stderr,"*Wo5: %x %x %x\n", (unsigned int) pointer,
 252                         (unsigned int) start_addr, *start_addr);
 253             }
 254             return 0;
 255
 256             /* the valid other immediate pointer objects */
 257         case SIMPLE_VECTOR_WIDETAG:
 258         case RATIO_WIDETAG:
 259         case COMPLEX_WIDETAG:
 260 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 261         case COMPLEX_SINGLE_FLOAT_WIDETAG:
 262 #endif
 263 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 264         case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 265 #endif
 266 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 267         case COMPLEX_LONG_FLOAT_WIDETAG:
 268 #endif
 269         case SIMPLE_ARRAY_WIDETAG:
 270         case COMPLEX_STRING_WIDETAG:
 271         case COMPLEX_BIT_VECTOR_WIDETAG:
 272         case COMPLEX_VECTOR_WIDETAG:
 273         case COMPLEX_ARRAY_WIDETAG:
 274         case VALUE_CELL_HEADER_WIDETAG:
 275         case SYMBOL_HEADER_WIDETAG:
 276         case FDEFN_WIDETAG:
 277         case CODE_HEADER_WIDETAG:
 278         case BIGNUM_WIDETAG:
 279         case SINGLE_FLOAT_WIDETAG:
 280         case DOUBLE_FLOAT_WIDETAG:
 281 #ifdef LONG_FLOAT_WIDETAG
 282         case LONG_FLOAT_WIDETAG:
 283 #endif
 284         case SIMPLE_STRING_WIDETAG:
 285         case SIMPLE_BIT_VECTOR_WIDETAG:
 286         case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 287         case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 288         case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 289         case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 290         case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 291 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 292         case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 293 #endif
 294 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 295         case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 296 #endif
 297 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 298         case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 299 #endif
 300 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 301         case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 302 #endif
 303         case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 304         case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 305 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 306         case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 307 #endif
 308 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 309         case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 310 #endif
 311 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 312         case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 313 #endif
 314 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 315         case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 316 #endif
 317         case SAP_WIDETAG:
 318         case WEAK_POINTER_WIDETAG:
 319             break;
 320
 321         default:
 322             if (pointer_filter_verbose) {
 323                 fprintf(stderr,"*Wo6: %x %x %x\n", (unsigned int) pointer,
 324                         (unsigned int) start_addr, *start_addr);
 325             }
 326             return 0;
 327         }
 328         break;
 329     default:
 330         if (pointer_filter_verbose) {
 331             fprintf(stderr,"*W?: %x %x %x\n", (unsigned int) pointer,
 332                     (unsigned int) start_addr, *start_addr);
 333         }
 334         return 0;
 335     }
 336
 337     /* looks good */
 338     return 1;
 339 }
 340
 341 #define MAX_STACK_POINTERS 256
 342 lispobj *valid_stack_locations[MAX_STACK_POINTERS];
 343 unsigned int num_valid_stack_locations;
 344
 345 #define MAX_STACK_RETURN_ADDRESSES 128
 346 lispobj *valid_stack_ra_locations[MAX_STACK_RETURN_ADDRESSES];
 347 lispobj *valid_stack_ra_code_objects[MAX_STACK_RETURN_ADDRESSES];
 348 unsigned int num_valid_stack_ra_locations;
 349
 350 /* Identify valid stack slots. */
 351 static void
 352 setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
 353 {
 354     lispobj *sp = lowaddr;
 355     num_valid_stack_locations = 0;
 356     num_valid_stack_ra_locations = 0;
 357     for (sp = lowaddr; sp < base; sp++) {
 358         lispobj thing = *sp;
 359         /* Find the object start address */
 360         lispobj *start_addr = search_dynamic_space((void *)thing);
 361         if (start_addr) {
 362             /* We need to allow raw pointers into Code objects for
 363              * return addresses. This will also pick up pointers to
 364              * functions in code objects. */
 365             if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
 366                 /* FIXME asserting here is a really dumb thing to do.
 367                  * If we've overflowed some arbitrary static limit, we
 368                  * should just refuse to purify, instead of killing
 369                  * the whole lisp session
 370                  */
 371                 gc_assert(num_valid_stack_ra_locations <
 372                           MAX_STACK_RETURN_ADDRESSES);
 373                 valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
 374                 valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
 375                     (lispobj *)((int)start_addr + OTHER_POINTER_LOWTAG);
 376             } else {
 377                 if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
 378                     gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
 379                     valid_stack_locations[num_valid_stack_locations++] = sp;
 380                 }
 381             }
 382         }
 383     }
 384     if (pointer_filter_verbose) {
 385         fprintf(stderr, "number of valid stack pointers = %d\n",
 386                 num_valid_stack_locations);
 387         fprintf(stderr, "number of stack return addresses = %d\n",
 388                 num_valid_stack_ra_locations);
 389     }
 390 }
 391
 392 static void
 393 pscav_i386_stack(void)
 394 {
 395     int i;
 396
 397     for (i = 0; i < num_valid_stack_locations; i++)
 398         pscav(valid_stack_locations[i], 1, 0);
 399
 400     for (i = 0; i < num_valid_stack_ra_locations; i++) {
 401         lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
 402         pscav(&code_obj, 1, 0);
 403         if (pointer_filter_verbose) {
 404             fprintf(stderr,"*C moved RA %x to %x; for code object %x to %x\n",
 405                     *valid_stack_ra_locations[i],
 406                     (int)(*valid_stack_ra_locations[i])
 407                     - ((int)valid_stack_ra_code_objects[i] - (int)code_obj),
 408                     (unsigned int) valid_stack_ra_code_objects[i], code_obj);
 409         }
 410         *valid_stack_ra_locations[i] =
 411             ((int)(*valid_stack_ra_locations[i])
 412              - ((int)valid_stack_ra_code_objects[i] - (int)code_obj));
 413     }
 414 }
 415 #endif
 416 #endif
 417
 418 \f
 419 static void
 420 pscav_later(lispobj *where, int count)
 421 {
 422     struct later *new;
 423
 424     if (count > LATERMAXCOUNT) {
 425         while (count > LATERMAXCOUNT) {
 426             pscav_later(where, LATERMAXCOUNT);
 427             count -= LATERMAXCOUNT;
 428             where += LATERMAXCOUNT;
 429         }
 430     }
 431     else {
 432         if (later_blocks == NULL || later_count == LATERBLOCKSIZE ||
 433             (later_count == LATERBLOCKSIZE-1 && count > 1)) {
 434             new  = (struct later *)malloc(sizeof(struct later));
 435             new->next = later_blocks;
 436             if (later_blocks && later_count < LATERBLOCKSIZE)
 437                 later_blocks->u[later_count].ptr = NULL;
 438             later_blocks = new;
 439             later_count = 0;
 440         }
 441
 442         if (count != 1)
 443             later_blocks->u[later_count++].count = count;
 444         later_blocks->u[later_count++].ptr = where;
 445     }
 446 }
 447
 448 static lispobj
 449 ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 450 {
 451     int nwords;
 452     lispobj result, *new, *old;
 453
 454     nwords = 1 + HeaderValue(header);
 455
 456     /* Allocate it */
 457     old = (lispobj *)native_pointer(thing);
 458     if (constant) {
 459         new = read_only_free;
 460         read_only_free += CEILING(nwords, 2);
 461     }
 462     else {
 463         new = static_free;
 464         static_free += CEILING(nwords, 2);
 465     }
 466
 467     /* Copy it. */
 468     bcopy(old, new, nwords * sizeof(lispobj));
 469
 470     /* Deposit forwarding pointer. */
 471     result = make_lispobj(new, lowtag_of(thing));
 472     *old = result;
 473
 474     /* Scavenge it. */
 475     pscav(new, nwords, constant);
 476
 477     return result;
 478 }
 479
 480 /* We need to look at the layout to see whether it is a pure structure
 481  * class, and only then can we transport as constant. If it is pure,
 482  * we can ALWAYS transport as a constant. */
 483 static lispobj
 484 ptrans_instance(lispobj thing, lispobj header, boolean constant)
 485 {
 486     lispobj layout = ((struct instance *)native_pointer(thing))->slots[0];
 487     lispobj pure = ((struct instance *)native_pointer(layout))->slots[15];
 488
 489     switch (pure) {
 490     case T:
 491         return (ptrans_boxed(thing, header, 1));
 492     case NIL:
 493         return (ptrans_boxed(thing, header, 0));
 494     case 0:
 495         {
 496             /* Substructure: special case for the COMPACT-INFO-ENVs,
 497              * where the instance may have a point to the dynamic
 498              * space placed into it (e.g. the cache-name slot), but
 499              * the lists and arrays at the time of a purify can be
 500              * moved to the RO space. */
 501             int nwords;
 502             lispobj result, *new, *old;
 503
 504             nwords = 1 + HeaderValue(header);
 505
 506             /* Allocate it */
 507             old = (lispobj *)native_pointer(thing);
 508             new = static_free;
 509             static_free += CEILING(nwords, 2);
 510
 511             /* Copy it. */
 512             bcopy(old, new, nwords * sizeof(lispobj));
 513
 514             /* Deposit forwarding pointer. */
 515             result = make_lispobj(new, lowtag_of(thing));
 516             *old = result;
 517
 518             /* Scavenge it. */
 519             pscav(new, nwords, 1);
 520
 521             return result;
 522         }
 523     default:
 524         gc_abort();
 525         return NIL; /* dummy value: return something ... */
 526     }
 527 }
 528
 529 static lispobj
 530 ptrans_fdefn(lispobj thing, lispobj header)
 531 {
 532     int nwords;
 533     lispobj result, *new, *old, oldfn;
 534     struct fdefn *fdefn;
 535
 536     nwords = 1 + HeaderValue(header);
 537
 538     /* Allocate it */
 539     old = (lispobj *)native_pointer(thing);
 540     new = static_free;
 541     static_free += CEILING(nwords, 2);
 542
 543     /* Copy it. */
 544     bcopy(old, new, nwords * sizeof(lispobj));
 545
 546     /* Deposit forwarding pointer. */
 547     result = make_lispobj(new, lowtag_of(thing));
 548     *old = result;
 549
 550     /* Scavenge the function. */
 551     fdefn = (struct fdefn *)new;
 552     oldfn = fdefn->fun;
 553     pscav(&fdefn->fun, 1, 0);
 554     if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
 555         fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 556
 557     return result;
 558 }
 559
 560 static lispobj
 561 ptrans_unboxed(lispobj thing, lispobj header)
 562 {
 563     int nwords;
 564     lispobj result, *new, *old;
 565
 566     nwords = 1 + HeaderValue(header);
 567
 568     /* Allocate it */
 569     old = (lispobj *)native_pointer(thing);
 570     new = read_only_free;
 571     read_only_free += CEILING(nwords, 2);
 572
 573     /* Copy it. */
 574     bcopy(old, new, nwords * sizeof(lispobj));
 575
 576     /* Deposit forwarding pointer. */
 577     result = make_lispobj(new , lowtag_of(thing));
 578     *old = result;
 579
 580     return result;
 581 }
 582
 583 static lispobj
 584 ptrans_vector(lispobj thing, int bits, int extra,
 585               boolean boxed, boolean constant)
 586 {
 587     struct vector *vector;
 588     int nwords;
 589     lispobj result, *new;
 590
 591     vector = (struct vector *)native_pointer(thing);
 592     nwords = 2 + (CEILING((fixnum_value(vector->length)+extra)*bits,32)>>5);
 593
 594     if (boxed && !constant) {
 595         new = static_free;
 596         static_free += CEILING(nwords, 2);
 597     }
 598     else {
 599         new = read_only_free;
 600         read_only_free += CEILING(nwords, 2);
 601     }
 602
 603     bcopy(vector, new, nwords * sizeof(lispobj));
 604
 605     result = make_lispobj(new, lowtag_of(thing));
 606     vector->header = result;
 607
 608     if (boxed)
 609         pscav(new, nwords, constant);
 610
 611     return result;
 612 }
 613
 614 #ifdef __i386__
 615 static void
 616 apply_code_fixups_during_purify(struct code *old_code, struct code *new_code)
 617 {
 618     int nheader_words, ncode_words, nwords;
 619     void  *constants_start_addr, *constants_end_addr;
 620     void  *code_start_addr, *code_end_addr;
 621     lispobj fixups = NIL;
 622     unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
 623     struct vector *fixups_vector;
 624
 625     ncode_words = fixnum_value(new_code->code_size);
 626     nheader_words = HeaderValue(*(lispobj *)new_code);
 627     nwords = ncode_words + nheader_words;
 628
 629     constants_start_addr = (void *)new_code + 5*4;
 630     constants_end_addr = (void *)new_code + nheader_words*4;
 631     code_start_addr = (void *)new_code + nheader_words*4;
 632     code_end_addr = (void *)new_code + nwords*4;
 633
 634     /* The first constant should be a pointer to the fixups for this
 635      * code objects. Check. */
 636     fixups = new_code->constants[0];
 637
 638     /* It will be 0 or the unbound-marker if there are no fixups, and
 639      * will be an other-pointer to a vector if it is valid. */
 640     if ((fixups==0) ||
 641         (fixups==UNBOUND_MARKER_WIDETAG) ||
 642         !is_lisp_pointer(fixups)) {
 643 #ifdef LISP_FEATURE_GENCGC
 644         /* Check for a possible errors. */
 645         sniff_code_object(new_code,displacement);
 646 #endif
 647         return;
 648     }
 649
 650     fixups_vector = (struct vector *)native_pointer(fixups);
 651
 652     /* Could be pointing to a forwarding pointer. */
 653     if (is_lisp_pointer(fixups) && (dynamic_pointer_p(fixups))
 654         && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
 655         /* If so then follow it. */
 656         fixups_vector =
 657             (struct vector *)native_pointer(*(lispobj *)fixups_vector);
 658     }
 659
 660     if (widetag_of(fixups_vector->header) ==
 661         SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
 662         /* We got the fixups for the code block. Now work through the
 663          * vector, and apply a fixup at each address. */
 664         int length = fixnum_value(fixups_vector->length);
 665         int i;
 666         for (i=0; i<length; i++) {
 667             unsigned offset = fixups_vector->data[i];
 668             /* Now check the current value of offset. */
 669             unsigned old_value =
 670                 *(unsigned *)((unsigned)code_start_addr + offset);
 671
 672             /* If it's within the old_code object then it must be an
 673              * absolute fixup (relative ones are not saved) */
 674             if ((old_value>=(unsigned)old_code)
 675                 && (old_value<((unsigned)old_code + nwords*4)))
 676                 /* So add the dispacement. */
 677                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 678                     + displacement;
 679             else
 680                 /* It is outside the old code object so it must be a relative
 681                  * fixup (absolute fixups are not saved). So subtract the
 682                  * displacement. */
 683                 *(unsigned *)((unsigned)code_start_addr + offset) = old_value
 684                     - displacement;
 685         }
 686     }
 687
 688     /* No longer need the fixups. */
 689     new_code->constants[0] = 0;
 690
 691 #ifdef LISP_FEATURE_GENCGC
 692     /* Check for possible errors. */
 693     sniff_code_object(new_code,displacement);
 694 #endif
 695 }
 696 #endif
 697
 698 static lispobj
 699 ptrans_code(lispobj thing)
 700 {
 701     struct code *code, *new;
 702     int nwords;
 703     lispobj func, result;
 704
 705     code = (struct code *)native_pointer(thing);
 706     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
 707
 708     new = (struct code *)read_only_free;
 709     read_only_free += CEILING(nwords, 2);
 710
 711     bcopy(code, new, nwords * sizeof(lispobj));
 712
 713 #ifdef LISP_FEATURE_X86
 714     apply_code_fixups_during_purify(code,new);
 715 #endif
 716
 717     result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 718
 719     /* Stick in a forwarding pointer for the code object. */
 720     *(lispobj *)code = result;
 721
 722     /* Put in forwarding pointers for all the functions. */
 723     for (func = code->entry_points;
 724          func != NIL;
 725          func = ((struct simple_fun *)native_pointer(func))->next) {
 726
 727         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 728
 729         *(lispobj *)native_pointer(func) = result + (func - thing);
 730     }
 731
 732     /* Arrange to scavenge the debug info later. */
 733     pscav_later(&new->debug_info, 1);
 734
 735     if (new->trace_table_offset & 0x3)
 736 #if 0
 737       pscav(&new->trace_table_offset, 1, 0);
 738 #else
 739       new->trace_table_offset = NIL; /* limit lifetime */
 740 #endif
 741
 742     /* Scavenge the constants. */
 743     pscav(new->constants, HeaderValue(new->header)-5, 1);
 744
 745     /* Scavenge all the functions. */
 746     pscav(&new->entry_points, 1, 1);
 747     for (func = new->entry_points;
 748          func != NIL;
 749          func = ((struct simple_fun *)native_pointer(func))->next) {
 750         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 751         gc_assert(!dynamic_pointer_p(func));
 752
 753 #ifdef __i386__
 754         /* Temporarly convert the self pointer to a real function pointer. */
 755         ((struct simple_fun *)native_pointer(func))->self
 756             -= FUN_RAW_ADDR_OFFSET;
 757 #endif
 758         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 759 #ifdef __i386__
 760         ((struct simple_fun *)native_pointer(func))->self
 761             += FUN_RAW_ADDR_OFFSET;
 762 #endif
 763         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
 764     }
 765
 766     return result;
 767 }
 768
 769 static lispobj
 770 ptrans_func(lispobj thing, lispobj header)
 771 {
 772     int nwords;
 773     lispobj code, *new, *old, result;
 774     struct simple_fun *function;
 775
 776     /* Thing can either be a function header, a closure function
 777      * header, a closure, or a funcallable-instance. If it's a closure
 778      * or a funcallable-instance, we do the same as ptrans_boxed.
 779      * Otherwise we have to do something strange, 'cause it is buried
 780      * inside a code object. */
 781
 782     if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG ||
 783         widetag_of(header) == CLOSURE_FUN_HEADER_WIDETAG) {
 784
 785         /* We can only end up here if the code object has not been
 786          * scavenged, because if it had been scavenged, forwarding pointers
 787          * would have been left behind for all the entry points. */
 788
 789         function = (struct simple_fun *)native_pointer(thing);
 790         code =
 791             make_lispobj
 792             ((native_pointer(thing) -
 793               (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
 794
 795         /* This will cause the function's header to be replaced with a
 796          * forwarding pointer. */
 797
 798         ptrans_code(code);
 799
 800         /* So we can just return that. */
 801         return function->header;
 802     }
 803     else {
 804         /* It's some kind of closure-like thing. */
 805         nwords = 1 + HeaderValue(header);
 806         old = (lispobj *)native_pointer(thing);
 807
 808         /* Allocate the new one. */
 809         if (widetag_of(header) == FUNCALLABLE_INSTANCE_HEADER_WIDETAG) {
 810             /* FINs *must* not go in read_only space. */
 811             new = static_free;
 812             static_free += CEILING(nwords, 2);
 813         }
 814         else {
 815             /* Closures can always go in read-only space, 'cause they
 816              * never change. */
 817
 818             new = read_only_free;
 819             read_only_free += CEILING(nwords, 2);
 820         }
 821         /* Copy it. */
 822         bcopy(old, new, nwords * sizeof(lispobj));
 823
 824         /* Deposit forwarding pointer. */
 825         result = make_lispobj(new, lowtag_of(thing));
 826         *old = result;
 827
 828         /* Scavenge it. */
 829         pscav(new, nwords, 0);
 830
 831         return result;
 832     }
 833 }
 834
 835 static lispobj
 836 ptrans_returnpc(lispobj thing, lispobj header)
 837 {
 838     lispobj code, new;
 839
 840     /* Find the corresponding code object. */
 841     code = thing - HeaderValue(header)*sizeof(lispobj);
 842
 843     /* Make sure it's been transported. */
 844     new = *(lispobj *)native_pointer(code);
 845     if (!forwarding_pointer_p(new))
 846         new = ptrans_code(code);
 847
 848     /* Maintain the offset: */
 849     return new + (thing - code);
 850 }
 851
 852 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 853
 854 static lispobj
 855 ptrans_list(lispobj thing, boolean constant)
 856 {
 857     struct cons *old, *new, *orig;
 858     int length;
 859
 860     if (constant)
 861         orig = (struct cons *)read_only_free;
 862     else
 863         orig = (struct cons *)static_free;
 864     length = 0;
 865
 866     do {
 867         /* Allocate a new cons cell. */
 868         old = (struct cons *)native_pointer(thing);
 869         if (constant) {
 870             new = (struct cons *)read_only_free;
 871             read_only_free += WORDS_PER_CONS;
 872         }
 873         else {
 874             new = (struct cons *)static_free;
 875             static_free += WORDS_PER_CONS;
 876         }
 877
 878         /* Copy the cons cell and keep a pointer to the cdr. */
 879         new->car = old->car;
 880         thing = new->cdr = old->cdr;
 881
 882         /* Set up the forwarding pointer. */
 883         *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 884
 885         /* And count this cell. */
 886         length++;
 887     } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
 888              dynamic_pointer_p(thing) &&
 889              !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 890
 891     /* Scavenge the list we just copied. */
 892     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 893
 894     return make_lispobj(orig, LIST_POINTER_LOWTAG);
 895 }
 896
 897 static lispobj
 898 ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 899 {
 900     switch (widetag_of(header)) {
 901       case BIGNUM_WIDETAG:
 902       case SINGLE_FLOAT_WIDETAG:
 903       case DOUBLE_FLOAT_WIDETAG:
 904 #ifdef LONG_FLOAT_WIDETAG
 905       case LONG_FLOAT_WIDETAG:
 906 #endif
 907 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
 908       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 909 #endif
 910 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
 911       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 912 #endif
 913 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
 914       case COMPLEX_LONG_FLOAT_WIDETAG:
 915 #endif
 916       case SAP_WIDETAG:
 917         return ptrans_unboxed(thing, header);
 918
 919       case RATIO_WIDETAG:
 920       case COMPLEX_WIDETAG:
 921       case SIMPLE_ARRAY_WIDETAG:
 922       case COMPLEX_STRING_WIDETAG:
 923       case COMPLEX_VECTOR_WIDETAG:
 924       case COMPLEX_ARRAY_WIDETAG:
 925         return ptrans_boxed(thing, header, constant);
 926
 927       case VALUE_CELL_HEADER_WIDETAG:
 928       case WEAK_POINTER_WIDETAG:
 929         return ptrans_boxed(thing, header, 0);
 930
 931       case SYMBOL_HEADER_WIDETAG:
 932         return ptrans_boxed(thing, header, 0);
 933
 934       case SIMPLE_STRING_WIDETAG:
 935         return ptrans_vector(thing, 8, 1, 0, constant);
 936
 937       case SIMPLE_BIT_VECTOR_WIDETAG:
 938         return ptrans_vector(thing, 1, 0, 0, constant);
 939
 940       case SIMPLE_VECTOR_WIDETAG:
 941         return ptrans_vector(thing, 32, 0, 1, constant);
 942
 943       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
 944         return ptrans_vector(thing, 2, 0, 0, constant);
 945
 946       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
 947         return ptrans_vector(thing, 4, 0, 0, constant);
 948
 949       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
 950 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
 951       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 952 #endif
 953         return ptrans_vector(thing, 8, 0, 0, constant);
 954
 955       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
 956 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
 957       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 958 #endif
 959         return ptrans_vector(thing, 16, 0, 0, constant);
 960
 961       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
 962 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
 963       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 964 #endif
 965 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
 966       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 967 #endif
 968         return ptrans_vector(thing, 32, 0, 0, constant);
 969
 970       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
 971         return ptrans_vector(thing, 32, 0, 0, constant);
 972
 973       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 974         return ptrans_vector(thing, 64, 0, 0, constant);
 975
 976 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
 977       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 978 #ifdef __i386__
 979         return ptrans_vector(thing, 96, 0, 0, constant);
 980 #endif
 981 #ifdef sparc
 982         return ptrans_vector(thing, 128, 0, 0, constant);
 983 #endif
 984 #endif
 985
 986 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
 987       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 988         return ptrans_vector(thing, 64, 0, 0, constant);
 989 #endif
 990
 991 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
 992       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 993         return ptrans_vector(thing, 128, 0, 0, constant);
 994 #endif
 995
 996 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
 997       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 998 #ifdef __i386__
 999         return ptrans_vector(thing, 192, 0, 0, constant);
1000 #endif
1001 #ifdef sparc
1002         return ptrans_vector(thing, 256, 0, 0, constant);
1003 #endif
1004 #endif
1005
1006       case CODE_HEADER_WIDETAG:
1007         return ptrans_code(thing);
1008
1009       case RETURN_PC_HEADER_WIDETAG:
1010         return ptrans_returnpc(thing, header);
1011
1012       case FDEFN_WIDETAG:
1013         return ptrans_fdefn(thing, header);
1014
1015       default:
1016         /* Should only come across other pointers to the above stuff. */
1017         gc_abort();
1018         return NIL;
1019     }
1020 }
1021
1022 static int
1023 pscav_fdefn(struct fdefn *fdefn)
1024 {
1025     boolean fix_func;
1026
1027     fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
1028     pscav(&fdefn->name, 1, 1);
1029     pscav(&fdefn->fun, 1, 0);
1030     if (fix_func)
1031         fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
1032     return sizeof(struct fdefn) / sizeof(lispobj);
1033 }
1034
1035 #ifdef __i386__
1036 /* now putting code objects in static space */
1037 static int
1038 pscav_code(struct code*code)
1039 {
1040     int nwords;
1041     lispobj func;
1042     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
1043
1044     /* Arrange to scavenge the debug info later. */
1045     pscav_later(&code->debug_info, 1);
1046
1047     /* Scavenge the constants. */
1048     pscav(code->constants, HeaderValue(code->header)-5, 1);
1049
1050     /* Scavenge all the functions. */
1051     pscav(&code->entry_points, 1, 1);
1052     for (func = code->entry_points;
1053          func != NIL;
1054          func = ((struct simple_fun *)native_pointer(func))->next) {
1055         gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
1056         gc_assert(!dynamic_pointer_p(func));
1057
1058 #ifdef __i386__
1059         /* Temporarly convert the self pointer to a real function
1060          * pointer. */
1061         ((struct simple_fun *)native_pointer(func))->self
1062             -= FUN_RAW_ADDR_OFFSET;
1063 #endif
1064         pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
1065 #ifdef __i386__
1066         ((struct simple_fun *)native_pointer(func))->self
1067             += FUN_RAW_ADDR_OFFSET;
1068 #endif
1069         pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
1070     }
1071
1072     return CEILING(nwords,2);
1073 }
1074 #endif
1075
1076 static lispobj *
1077 pscav(lispobj *addr, int nwords, boolean constant)
1078 {
1079     lispobj thing, *thingp, header;
1080     int count = 0; /* (0 = dummy init value to stop GCC warning) */
1081     struct vector *vector;
1082
1083     while (nwords > 0) {
1084         thing = *addr;
1085         if (is_lisp_pointer(thing)) {
1086             /* It's a pointer. Is it something we might have to move? */
1087             if (dynamic_pointer_p(thing)) {
1088                 /* Maybe. Have we already moved it? */
1089                 thingp = (lispobj *)native_pointer(thing);
1090                 header = *thingp;
1091                 if (is_lisp_pointer(header) && forwarding_pointer_p(header))
1092                     /* Yep, so just copy the forwarding pointer. */
1093                     thing = header;
1094                 else {
1095                     /* Nope, copy the object. */
1096                     switch (lowtag_of(thing)) {
1097                       case FUN_POINTER_LOWTAG:
1098                         thing = ptrans_func(thing, header);
1099                         break;
1100
1101                       case LIST_POINTER_LOWTAG:
1102                         thing = ptrans_list(thing, constant);
1103                         break;
1104
1105                       case INSTANCE_POINTER_LOWTAG:
1106                         thing = ptrans_instance(thing, header, constant);
1107                         break;
1108
1109                       case OTHER_POINTER_LOWTAG:
1110                         thing = ptrans_otherptr(thing, header, constant);
1111                         break;
1112
1113                       default:
1114                         /* It was a pointer, but not one of them? */
1115                         gc_abort();
1116                     }
1117                 }
1118                 *addr = thing;
1119             }
1120             count = 1;
1121         }
1122         else if (thing & 3) {
1123             /* It's an other immediate. Maybe the header for an unboxed */
1124             /* object. */
1125             switch (widetag_of(thing)) {
1126               case BIGNUM_WIDETAG:
1127               case SINGLE_FLOAT_WIDETAG:
1128               case DOUBLE_FLOAT_WIDETAG:
1129 #ifdef LONG_FLOAT_WIDETAG
1130               case LONG_FLOAT_WIDETAG:
1131 #endif
1132               case SAP_WIDETAG:
1133                 /* It's an unboxed simple object. */
1134                 count = HeaderValue(thing)+1;
1135                 break;
1136
1137               case SIMPLE_VECTOR_WIDETAG:
1138                   if (HeaderValue(thing) == subtype_VectorValidHashing) {
1139                     *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
1140                         SIMPLE_VECTOR_WIDETAG;
1141                   }
1142                 count = 1;
1143                 break;
1144
1145               case SIMPLE_STRING_WIDETAG:
1146                 vector = (struct vector *)addr;
1147                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,4)+2,2);
1148                 break;
1149
1150               case SIMPLE_BIT_VECTOR_WIDETAG:
1151                 vector = (struct vector *)addr;
1152                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
1153                 break;
1154
1155               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
1156                 vector = (struct vector *)addr;
1157                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
1158                 break;
1159
1160               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
1161                 vector = (struct vector *)addr;
1162                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
1163                 break;
1164
1165               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
1166 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
1167               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
1168 #endif
1169                 vector = (struct vector *)addr;
1170                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
1171                 break;
1172
1173               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
1174 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
1175               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
1176 #endif
1177                 vector = (struct vector *)addr;
1178                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
1179                 break;
1180
1181               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
1182 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
1183               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
1184 #endif
1185 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
1186               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
1187 #endif
1188                 vector = (struct vector *)addr;
1189                 count = CEILING(fixnum_value(vector->length)+2,2);
1190                 break;
1191
1192               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
1193                 vector = (struct vector *)addr;
1194                 count = CEILING(fixnum_value(vector->length)+2,2);
1195                 break;
1196
1197               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
1198 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
1199               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
1200 #endif
1201                 vector = (struct vector *)addr;
1202                 count = fixnum_value(vector->length)*2+2;
1203                 break;
1204
1205 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
1206               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
1207                 vector = (struct vector *)addr;
1208 #ifdef __i386__
1209                 count = fixnum_value(vector->length)*3+2;
1210 #endif
1211 #ifdef sparc
1212                 count = fixnum_value(vector->length)*4+2;
1213 #endif
1214                 break;
1215 #endif
1216
1217 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
1218               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
1219                 vector = (struct vector *)addr;
1220                 count = fixnum_value(vector->length)*4+2;
1221                 break;
1222 #endif
1223
1224 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
1225               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
1226                 vector = (struct vector *)addr;
1227 #ifdef __i386__
1228                 count = fixnum_value(vector->length)*6+2;
1229 #endif
1230 #ifdef sparc
1231                 count = fixnum_value(vector->length)*8+2;
1232 #endif
1233                 break;
1234 #endif
1235
1236               case CODE_HEADER_WIDETAG:
1237 #ifndef __i386__
1238                 gc_abort(); /* no code headers in static space */
1239 #else
1240                 count = pscav_code((struct code*)addr);
1241 #endif
1242                 break;
1243
1244               case SIMPLE_FUN_HEADER_WIDETAG:
1245               case CLOSURE_FUN_HEADER_WIDETAG:
1246               case RETURN_PC_HEADER_WIDETAG:
1247                 /* We should never hit any of these, 'cause they occur
1248                  * buried in the middle of code objects. */
1249                 gc_abort();
1250                 break;
1251
1252 #ifdef __i386__
1253               case CLOSURE_HEADER_WIDETAG:
1254               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
1255                 /* The function self pointer needs special care on the
1256                  * x86 because it is the real entry point. */
1257                 {
1258                   lispobj fun = ((struct closure *)addr)->fun
1259                     - FUN_RAW_ADDR_OFFSET;
1260                   pscav(&fun, 1, constant);
1261                   ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
1262                 }
1263                 count = 2;
1264                 break;
1265 #endif
1266
1267               case WEAK_POINTER_WIDETAG:
1268                 /* Weak pointers get preserved during purify, 'cause I
1269                  * don't feel like figuring out how to break them. */
1270                 pscav(addr+1, 2, constant);
1271                 count = 4;
1272                 break;
1273
1274               case FDEFN_WIDETAG:
1275                 /* We have to handle fdefn objects specially, so we
1276                  * can fix up the raw function address. */
1277                 count = pscav_fdefn((struct fdefn *)addr);
1278                 break;
1279
1280               default:
1281                 count = 1;
1282                 break;
1283             }
1284         }
1285         else {
1286             /* It's a fixnum. */
1287             count = 1;
1288         }
1289
1290         addr += count;
1291         nwords -= count;
1292     }
1293
1294     return addr;
1295 }
1296
1297 int
1298 purify(lispobj static_roots, lispobj read_only_roots)
1299 {
1300     lispobj *clean;
1301     int count, i;
1302     struct later *laters, *next;
1303
1304
1305 #ifdef PRINTNOISE
1306     printf("[doing purification:");
1307     fflush(stdout);
1308 #endif
1309 #ifdef LISP_FEATURE_GENCGC
1310     gc_alloc_update_all_page_tables();
1311 #endif
1312     if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX)) != 0) {
1313         /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
1314          * its error simply by a. printing a string b. to stdout instead
1315          * of stderr. */
1316         printf(" Ack! Can't purify interrupt contexts. ");
1317         fflush(stdout);
1318         return 0;
1319     }
1320
1321 #if defined(__i386__)
1322     dynamic_space_free_pointer =
1323       (lispobj*)SymbolValue(ALLOCATION_POINTER);
1324 #endif
1325
1326     read_only_end = read_only_free =
1327         (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER);
1328     static_end = static_free =
1329         (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER);
1330
1331 #ifdef PRINTNOISE
1332     printf(" roots");
1333     fflush(stdout);
1334 #endif
1335
1336 #if (defined(LISP_FEATURE_GENCGC) && defined(LISP_FEATURE_X86))
1337     gc_assert((lispobj *)CONTROL_STACK_END > ((&read_only_roots)+1));
1338     setup_i386_stack_scav(((&static_roots)-2), (lispobj *)CONTROL_STACK_END);
1339 #endif
1340
1341     pscav(&static_roots, 1, 0);
1342     pscav(&read_only_roots, 1, 1);
1343
1344 #ifdef PRINTNOISE
1345     printf(" handlers");
1346     fflush(stdout);
1347 #endif
1348     pscav((lispobj *) interrupt_handlers,
1349           sizeof(interrupt_handlers) / sizeof(lispobj),
1350           0);
1351
1352 #ifdef PRINTNOISE
1353     printf(" stack");
1354     fflush(stdout);
1355 #endif
1356 #ifndef __i386__
1357     pscav((lispobj *)CONTROL_STACK_START,
1358           current_control_stack_pointer - (lispobj *)CONTROL_STACK_START,
1359           0);
1360 #else
1361 #ifdef LISP_FEATURE_GENCGC
1362     pscav_i386_stack();
1363 #endif
1364 #endif
1365
1366 #ifdef PRINTNOISE
1367     printf(" bindings");
1368     fflush(stdout);
1369 #endif
1370 #if !defined(__i386__)
1371     pscav( (lispobj *)BINDING_STACK_START,
1372           (lispobj *)current_binding_stack_pointer - (lispobj *)BINDING_STACK_START,
1373           0);
1374 #else
1375     pscav( (lispobj *)BINDING_STACK_START,
1376           (lispobj *)SymbolValue(BINDING_STACK_POINTER) -
1377           (lispobj *)BINDING_STACK_START,
1378           0);
1379 #endif
1380
1381     /* The original CMU CL code had scavenge-read-only-space code
1382      * controlled by the Lisp-level variable
1383      * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
1384      * wasn't documented under what circumstances it was useful or
1385      * safe to turn it on, so it's been turned off in SBCL. If you
1386      * want/need this functionality, and can test and document it,
1387      * please submit a patch. */
1388 #if 0
1389     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
1390         && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
1391       unsigned  read_only_space_size =
1392           (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
1393           (lispobj *)READ_ONLY_SPACE_START;
1394       fprintf(stderr,
1395               "scavenging read only space: %d bytes\n",
1396               read_only_space_size * sizeof(lispobj));
1397       pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
1398     }
1399 #endif
1400
1401 #ifdef PRINTNOISE
1402     printf(" static");
1403     fflush(stdout);
1404 #endif
1405     clean = (lispobj *)STATIC_SPACE_START;
1406     do {
1407         while (clean != static_free)
1408             clean = pscav(clean, static_free - clean, 0);
1409         laters = later_blocks;
1410         count = later_count;
1411         later_blocks = NULL;
1412         later_count = 0;
1413         while (laters != NULL) {
1414             for (i = 0; i < count; i++) {
1415                 if (laters->u[i].count == 0) {
1416                     ;
1417                 } else if (laters->u[i].count <= LATERMAXCOUNT) {
1418                     pscav(laters->u[i+1].ptr, laters->u[i].count, 1);
1419                     i++;
1420                 } else {
1421                     pscav(laters->u[i].ptr, 1, 1);
1422                 }
1423             }
1424             next = laters->next;
1425             free(laters);
1426             laters = next;
1427             count = LATERBLOCKSIZE;
1428         }
1429     } while (clean != static_free || later_blocks != NULL);
1430
1431 #ifdef PRINTNOISE
1432     printf(" cleanup");
1433     fflush(stdout);
1434 #endif
1435
1436     os_zero((os_vm_address_t) current_dynamic_space,
1437             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
1438
1439     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
1440      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
1441 #ifndef __i386__
1442     os_zero((os_vm_address_t) current_control_stack_pointer,
1443             (os_vm_size_t) (CONTROL_STACK_SIZE -
1444                             ((current_control_stack_pointer -
1445                               (lispobj *)CONTROL_STACK_START) *
1446                              sizeof(lispobj))));
1447 #endif
1448
1449     /* It helps to update the heap free pointers so that free_heap can
1450      * verify after it's done. */
1451     SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free);
1452     SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free);
1453
1454 #if !defined(__i386__)
1455     dynamic_space_free_pointer = current_dynamic_space;
1456 #else
1457 #if defined LISP_FEATURE_GENCGC
1458     gc_free_heap();
1459 #else
1460 #error unsupported case /* in CMU CL, was "ibmrt using GC" */
1461 #endif
1462 #endif
1463
1464 #ifdef PRINTNOISE
1465     printf(" done]\n");
1466     fflush(stdout);
1467 #endif
1468
1469     return 0;
1470 }