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