boehm-gc/dbg_mlc.c - gcc - Git at Google

 /*
  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
  * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
  * Copyright (c) 1997 by Silicon Graphics.  All rights reserved.
  * Copyright (c) 1999 by Hewlett-Packard Company.  All rights reserved.
  *
  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
  *
  * Permission is hereby granted to use or copy this program
  * for any purpose,  provided the above notices are retained on all copies.
  * Permission to modify the code and to distribute modified code is granted,
  * provided the above notices are retained, and a notice that the code was
  * modified is included with the above copyright notice.
  */

 #include "dbg_mlc.h"

 void GC_default_print_heap_obj_proc();
 GC_API void GC_register_finalizer_no_order
     	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 		  GC_finalization_proc *ofn, GC_PTR *ocd));


 /* Check whether object with base pointer p has debugging info	*/
 /* p is assumed to point to a legitimate object in our part	*/
 /* of the heap.							*/
 GC_bool GC_has_debug_info(p)
 ptr_t p;
 {
     register oh * ohdr = (oh *)p;
     register ptr_t body = (ptr_t)(ohdr + 1);
     register word sz = GC_size((ptr_t) ohdr);

     if (HBLKPTR((ptr_t)ohdr) != HBLKPTR((ptr_t)body)
         || sz < sizeof (oh)) {
         return(FALSE);
     }
     if (ohdr -> oh_sz == sz) {
     	/* Object may have had debug info, but has been deallocated	*/
     	return(FALSE);
     }
     if (ohdr -> oh_sf == (START_FLAG ^ (word)body)) return(TRUE);
     if (((word *)ohdr)[BYTES_TO_WORDS(sz)-1] == (END_FLAG ^ (word)body)) {
         return(TRUE);
     }
     return(FALSE);
 }

 #ifdef KEEP_BACK_PTRS
   /* Store back pointer to source in dest, if that appears to be possible. */
   /* This is not completely safe, since we may mistakenly conclude that	   */
   /* dest has a debugging wrapper.  But the error probability is very	   */
   /* small, and this shouldn't be used in production code.		   */
   /* We assume that dest is the real base pointer.  Source will usually    */
   /* be a pointer to the interior of an object.				   */
   void GC_store_back_pointer(ptr_t source, ptr_t dest)
   {
     if (GC_has_debug_info(dest)) {
       ((oh *)dest) -> oh_back_ptr = (ptr_t)HIDE_POINTER(source);
     }
   }

   void GC_marked_for_finalization(ptr_t dest) {
     GC_store_back_pointer(MARKED_FOR_FINALIZATION, dest);
   }

   /* Store information about the object referencing dest in *base_p	*/
   /* and *offset_p.							*/
   /*   source is root ==> *base_p = address, *offset_p = 0		*/
   /*   source is heap object ==> *base_p != 0, *offset_p = offset 	*/
   /*   Returns 1 on success, 0 if source couldn't be determined.	*/
   /* Dest can be any address within a heap object.			*/
   GC_ref_kind GC_get_back_ptr_info(void *dest, void **base_p, size_t *offset_p)
   {
     oh * hdr = (oh *)GC_base(dest);
     ptr_t bp;
     ptr_t bp_base;
     if (!GC_has_debug_info((ptr_t) hdr)) return GC_NO_SPACE;
     bp = hdr -> oh_back_ptr;
     if (MARKED_FOR_FINALIZATION == bp) return GC_FINALIZER_REFD;
     if (MARKED_FROM_REGISTER == bp) return GC_REFD_FROM_REG;
     if (0 == bp) return GC_UNREFERENCED;
     bp = REVEAL_POINTER(bp);
     bp_base = GC_base(bp);
     if (0 == bp_base) {
       *base_p = bp;
       *offset_p = 0;
       return GC_REFD_FROM_ROOT;
     } else {
       if (GC_has_debug_info(bp_base)) bp_base += sizeof(oh);
       *base_p = bp_base;
       *offset_p = bp - bp_base;
       return GC_REFD_FROM_HEAP;
     }
   }

   /* Generate a random heap address.		*/
   /* The resulting address is in the heap, but	*/
   /* not necessarily inside a valid object.	*/
   void *GC_generate_random_heap_address(void)
   {
     int i;
     int heap_offset = random() % GC_heapsize;
     for (i = 0; i < GC_n_heap_sects; ++ i) {
 	int size = GC_heap_sects[i].hs_bytes;
 	if (heap_offset < size) {
 	    return GC_heap_sects[i].hs_start + heap_offset;
 	} else {
 	    heap_offset -= size;
 	}
     }
     ABORT("GC_generate_random_heap_address: size inconsistency");
     /*NOTREACHED*/
     return 0;
   }

   /* Generate a random address inside a valid marked heap object. */
   void *GC_generate_random_valid_address(void)
   {
     ptr_t result;
     ptr_t base;
     for (;;) {
 	result = GC_generate_random_heap_address();
   	base = GC_base(result);
 	if (0 == base) continue;
 	if (!GC_is_marked(base)) continue;
 	return result;
     }
   }

   /* Print back trace for p */
   void GC_print_backtrace(void *p)
   {
     void *current = p;
     int i;
     GC_ref_kind source;
     size_t offset;
     void *base;

     GC_print_heap_obj(GC_base(current));
     GC_err_printf0("\n");
     for (i = 0; ; ++i) {
       source = GC_get_back_ptr_info(current, &base, &offset);
       if (GC_UNREFERENCED == source) {
 	GC_err_printf0("Reference could not be found\n");
   	goto out;
       }
       if (GC_NO_SPACE == source) {
 	GC_err_printf0("No debug info in object: Can't find reference\n");
 	goto out;
       }
       GC_err_printf1("Reachable via %d levels of pointers from ",
 		 (unsigned long)i);
       switch(source) {
 	case GC_REFD_FROM_ROOT:
 	  GC_err_printf1("root at 0x%lx\n", (unsigned long)base);
 	  goto out;
 	case GC_REFD_FROM_REG:
 	  GC_err_printf0("root in register\n");
 	  goto out;
 	case GC_FINALIZER_REFD:
 	  GC_err_printf0("list of finalizable objects\n");
 	  goto out;
 	case GC_REFD_FROM_HEAP:
 	  GC_err_printf1("offset %ld in object:\n", (unsigned long)offset);
 	  /* Take GC_base(base) to get real base, i.e. header. */
 	  GC_print_heap_obj(GC_base(base));
 	  GC_err_printf0("\n");
 	  break;
       }
       current = base;
     }
     out:;
   }

   /* Force a garbage collection and generate a backtrace from a	*/
   /* random heap address.					*/
   void GC_generate_random_backtrace(void)
   {
     void * current;
     GC_gcollect();
     current = GC_generate_random_valid_address();
     GC_printf1("Chose address 0x%lx in object\n", (unsigned long)current);
     GC_print_backtrace(current);
   }

 #endif /* KEEP_BACK_PTRS */

 /* Store debugging info into p.  Return displaced pointer. */
 /* Assumes we don't hold allocation lock.		   */
 ptr_t GC_store_debug_info(p, sz, string, integer)
 register ptr_t p;	/* base pointer */
 word sz; 	/* bytes */
 char * string;
 word integer;
 {
     register word * result = (word *)((oh *)p + 1);
     DCL_LOCK_STATE;

     /* There is some argument that we should dissble signals here.	*/
     /* But that's expensive.  And this way things should only appear	*/
     /* inconsistent while we're in the handler.				*/
     LOCK();
 #   ifdef KEEP_BACK_PTRS
       ((oh *)p) -> oh_back_ptr = 0;
 #   endif
     ((oh *)p) -> oh_string = string;
     ((oh *)p) -> oh_int = integer;
     ((oh *)p) -> oh_sz = sz;
     ((oh *)p) -> oh_sf = START_FLAG ^ (word)result;
     ((word *)p)[BYTES_TO_WORDS(GC_size(p))-1] =
          result[ROUNDED_UP_WORDS(sz)] = END_FLAG ^ (word)result;
     UNLOCK();
     return((ptr_t)result);
 }

 /* Check the object with debugging info at ohdr		*/
 /* return NIL if it's OK.  Else return clobbered	*/
 /* address.						*/
 ptr_t GC_check_annotated_obj(ohdr)
 register oh * ohdr;
 {
     register ptr_t body = (ptr_t)(ohdr + 1);
     register word gc_sz = GC_size((ptr_t)ohdr);
     if (ohdr -> oh_sz + DEBUG_BYTES > gc_sz) {
         return((ptr_t)(&(ohdr -> oh_sz)));
     }
     if (ohdr -> oh_sf != (START_FLAG ^ (word)body)) {
         return((ptr_t)(&(ohdr -> oh_sf)));
     }
     if (((word *)ohdr)[BYTES_TO_WORDS(gc_sz)-1] != (END_FLAG ^ (word)body)) {
         return((ptr_t)((word *)ohdr + BYTES_TO_WORDS(gc_sz)-1));
     }
     if (((word *)body)[ROUNDED_UP_WORDS(ohdr -> oh_sz)]
         != (END_FLAG ^ (word)body)) {
         return((ptr_t)((word *)body + ROUNDED_UP_WORDS(ohdr -> oh_sz)));
     }
     return(0);
 }

 void GC_print_obj(p)
 ptr_t p;
 {
     register oh * ohdr = (oh *)GC_base(p);

     GC_err_printf1("0x%lx (", ((unsigned long)ohdr + sizeof(oh)));
     GC_err_puts(ohdr -> oh_string);
     GC_err_printf2(":%ld, sz=%ld)\n", (unsigned long)(ohdr -> oh_int),
         			      (unsigned long)(ohdr -> oh_sz));
     PRINT_CALL_CHAIN(ohdr);
 }

 void GC_debug_print_heap_obj_proc(p)
 ptr_t p;
 {
     if (GC_has_debug_info(p)) {
 	GC_print_obj(p);
     } else {
 	GC_default_print_heap_obj_proc(p);
     }
 }

 void GC_print_smashed_obj(p, clobbered_addr)
 ptr_t p, clobbered_addr;
 {
     register oh * ohdr = (oh *)GC_base(p);

     GC_err_printf2("0x%lx in object at 0x%lx(", (unsigned long)clobbered_addr,
     					        (unsigned long)p);
     if (clobbered_addr <= (ptr_t)(&(ohdr -> oh_sz))
         || ohdr -> oh_string == 0) {
         GC_err_printf1("<smashed>, appr. sz = %ld)\n",
         	       (GC_size((ptr_t)ohdr) - DEBUG_BYTES));
     } else {
         if (ohdr -> oh_string[0] == '\0') {
             GC_err_puts("EMPTY(smashed?)");
         } else {
             GC_err_puts(ohdr -> oh_string);
         }
         GC_err_printf2(":%ld, sz=%ld)\n", (unsigned long)(ohdr -> oh_int),
         			          (unsigned long)(ohdr -> oh_sz));
         PRINT_CALL_CHAIN(ohdr);
     }
 }

 void GC_check_heap_proc();

 void GC_start_debugging()
 {
     GC_check_heap = GC_check_heap_proc;
     GC_print_heap_obj = GC_debug_print_heap_obj_proc;
     GC_debugging_started = TRUE;
     GC_register_displacement((word)sizeof(oh));
 }

 # if defined(__STDC__) || defined(__cplusplus)
     void GC_debug_register_displacement(GC_word offset)
 # else
     void GC_debug_register_displacement(offset)
     GC_word offset;
 # endif
 {
     GC_register_displacement(offset);
     GC_register_displacement((word)sizeof(oh) + offset);
 }

 # ifdef __STDC__
     GC_PTR GC_debug_malloc(size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc(lb, s, i)
     size_t lb;
     char * s;
     int i;
 #   ifdef GC_ADD_CALLER
 	--> GC_ADD_CALLER not implemented for K&R C
 #   endif
 # endif
 {
     GC_PTR result = GC_malloc(lb + DEBUG_BYTES);

     if (result == 0) {
         GC_err_printf1("GC_debug_malloc(%ld) returning NIL (",
         	       (unsigned long) lb);
         GC_err_puts(s);
         GC_err_printf1(":%ld)\n", (unsigned long)i);
         return(0);
     }
     if (!GC_debugging_started) {
     	GC_start_debugging();
     }
     ADD_CALL_CHAIN(result, ra);
     return (GC_store_debug_info(result, (word)lb, s, (word)i));
 }

 # ifdef __STDC__
     GC_PTR GC_debug_generic_malloc(size_t lb, int k, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc(lb, k, s, i)
     size_t lb;
     int k;
     char * s;
     int i;
 #   ifdef GC_ADD_CALLER
 	--> GC_ADD_CALLER not implemented for K&R C
 #   endif
 # endif
 {
     GC_PTR result = GC_generic_malloc(lb + DEBUG_BYTES, k);

     if (result == 0) {
         GC_err_printf1("GC_debug_malloc(%ld) returning NIL (",
         	       (unsigned long) lb);
         GC_err_puts(s);
         GC_err_printf1(":%ld)\n", (unsigned long)i);
         return(0);
     }
     if (!GC_debugging_started) {
     	GC_start_debugging();
     }
     ADD_CALL_CHAIN(result, ra);
     return (GC_store_debug_info(result, (word)lb, s, (word)i));
 }

 #ifdef STUBBORN_ALLOC
 # ifdef __STDC__
     GC_PTR GC_debug_malloc_stubborn(size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc_stubborn(lb, s, i)
     size_t lb;
     char * s;
     int i;
 # endif
 {
     GC_PTR result = GC_malloc_stubborn(lb + DEBUG_BYTES);

     if (result == 0) {
         GC_err_printf1("GC_debug_malloc(%ld) returning NIL (",
         	       (unsigned long) lb);
         GC_err_puts(s);
         GC_err_printf1(":%ld)\n", (unsigned long)i);
         return(0);
     }
     if (!GC_debugging_started) {
     	GC_start_debugging();
     }
     ADD_CALL_CHAIN(result, ra);
     return (GC_store_debug_info(result, (word)lb, s, (word)i));
 }

 void GC_debug_change_stubborn(p)
 GC_PTR p;
 {
     register GC_PTR q = GC_base(p);
     register hdr * hhdr;

     if (q == 0) {
         GC_err_printf1("Bad argument: 0x%lx to GC_debug_change_stubborn\n",
         	       (unsigned long) p);
         ABORT("GC_debug_change_stubborn: bad arg");
     }
     hhdr = HDR(q);
     if (hhdr -> hb_obj_kind != STUBBORN) {
         GC_err_printf1("GC_debug_change_stubborn arg not stubborn: 0x%lx\n",
         	       (unsigned long) p);
         ABORT("GC_debug_change_stubborn: arg not stubborn");
     }
     GC_change_stubborn(q);
 }

 void GC_debug_end_stubborn_change(p)
 GC_PTR p;
 {
     register GC_PTR q = GC_base(p);
     register hdr * hhdr;

     if (q == 0) {
         GC_err_printf1("Bad argument: 0x%lx to GC_debug_end_stubborn_change\n",
         	       (unsigned long) p);
         ABORT("GC_debug_end_stubborn_change: bad arg");
     }
     hhdr = HDR(q);
     if (hhdr -> hb_obj_kind != STUBBORN) {
         GC_err_printf1("debug_end_stubborn_change arg not stubborn: 0x%lx\n",
         	       (unsigned long) p);
         ABORT("GC_debug_end_stubborn_change: arg not stubborn");
     }
     GC_end_stubborn_change(q);
 }

 #else /* !STUBBORN_ALLOC */

 # ifdef __STDC__
     GC_PTR GC_debug_malloc_stubborn(size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc_stubborn(lb, s, i)
     size_t lb;
     char * s;
     int i;
 # endif
 {
     return GC_debug_malloc(lb, OPT_RA s, i);
 }

 void GC_debug_change_stubborn(p)
 GC_PTR p;
 {
 }

 void GC_debug_end_stubborn_change(p)
 GC_PTR p;
 {
 }

 #endif /* !STUBBORN_ALLOC */

 # ifdef __STDC__
     GC_PTR GC_debug_malloc_atomic(size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc_atomic(lb, s, i)
     size_t lb;
     char * s;
     int i;
 # endif
 {
     GC_PTR result = GC_malloc_atomic(lb + DEBUG_BYTES);

     if (result == 0) {
         GC_err_printf1("GC_debug_malloc_atomic(%ld) returning NIL (",
         	      (unsigned long) lb);
         GC_err_puts(s);
         GC_err_printf1(":%ld)\n", (unsigned long)i);
         return(0);
     }
     if (!GC_debugging_started) {
         GC_start_debugging();
     }
     ADD_CALL_CHAIN(result, ra);
     return (GC_store_debug_info(result, (word)lb, s, (word)i));
 }

 # ifdef __STDC__
     GC_PTR GC_debug_malloc_uncollectable(size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc_uncollectable(lb, s, i)
     size_t lb;
     char * s;
     int i;
 # endif
 {
     GC_PTR result = GC_malloc_uncollectable(lb + DEBUG_BYTES);

     if (result == 0) {
         GC_err_printf1("GC_debug_malloc_uncollectable(%ld) returning NIL (",
         	      (unsigned long) lb);
         GC_err_puts(s);
         GC_err_printf1(":%ld)\n", (unsigned long)i);
         return(0);
     }
     if (!GC_debugging_started) {
         GC_start_debugging();
     }
     ADD_CALL_CHAIN(result, ra);
     return (GC_store_debug_info(result, (word)lb, s, (word)i));
 }

 #ifdef ATOMIC_UNCOLLECTABLE
 # ifdef __STDC__
     GC_PTR GC_debug_malloc_atomic_uncollectable(size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_malloc_atomic_uncollectable(lb, s, i)
     size_t lb;
     char * s;
     int i;
 # endif
 {
     GC_PTR result = GC_malloc_atomic_uncollectable(lb + DEBUG_BYTES);

     if (result == 0) {
         GC_err_printf1(
 		"GC_debug_malloc_atomic_uncollectable(%ld) returning NIL (",
                 (unsigned long) lb);
         GC_err_puts(s);
         GC_err_printf1(":%ld)\n", (unsigned long)i);
         return(0);
     }
     if (!GC_debugging_started) {
         GC_start_debugging();
     }
     ADD_CALL_CHAIN(result, ra);
     return (GC_store_debug_info(result, (word)lb, s, (word)i));
 }
 #endif /* ATOMIC_UNCOLLECTABLE */

 # ifdef __STDC__
     void GC_debug_free(GC_PTR p)
 # else
     void GC_debug_free(p)
     GC_PTR p;
 # endif
 {
     register GC_PTR base;
     register ptr_t clobbered;

     if (0 == p) return;
     base = GC_base(p);
     if (base == 0) {
         GC_err_printf1("Attempt to free invalid pointer %lx\n",
         	       (unsigned long)p);
         ABORT("free(invalid pointer)");
     }
     if ((ptr_t)p - (ptr_t)base != sizeof(oh)) {
         GC_err_printf1(
         	  "GC_debug_free called on pointer %lx wo debugging info\n",
         	  (unsigned long)p);
     } else {
       clobbered = GC_check_annotated_obj((oh *)base);
       if (clobbered != 0) {
         if (((oh *)base) -> oh_sz == GC_size(base)) {
             GC_err_printf0(
                   "GC_debug_free: found previously deallocated (?) object at ");
         } else {
             GC_err_printf0("GC_debug_free: found smashed location at ");
         }
         GC_print_smashed_obj(p, clobbered);
       }
       /* Invalidate size */
       ((oh *)base) -> oh_sz = GC_size(base);
     }
     if (GC_find_leak) {
         GC_free(base);
     } else {
 	register hdr * hhdr = HDR(p);
 	GC_bool uncollectable = FALSE;

         if (hhdr ->  hb_obj_kind == UNCOLLECTABLE) {
 	    uncollectable = TRUE;
 	}
 #	ifdef ATOMIC_UNCOLLECTABLE
 	    if (hhdr ->  hb_obj_kind == AUNCOLLECTABLE) {
 		    uncollectable = TRUE;
 	    }
 #	endif
 	if (uncollectable) GC_free(base);
     } /* !GC_find_leak */
 }

 # ifdef __STDC__
     GC_PTR GC_debug_realloc(GC_PTR p, size_t lb, GC_EXTRA_PARAMS)
 # else
     GC_PTR GC_debug_realloc(p, lb, s, i)
     GC_PTR p;
     size_t lb;
     char *s;
     int i;
 # endif
 {
     register GC_PTR base = GC_base(p);
     register ptr_t clobbered;
     register GC_PTR result;
     register size_t copy_sz = lb;
     register size_t old_sz;
     register hdr * hhdr;

     if (p == 0) return(GC_debug_malloc(lb, OPT_RA s, i));
     if (base == 0) {
         GC_err_printf1(
               "Attempt to reallocate invalid pointer %lx\n", (unsigned long)p);
         ABORT("realloc(invalid pointer)");
     }
     if ((ptr_t)p - (ptr_t)base != sizeof(oh)) {
         GC_err_printf1(
         	"GC_debug_realloc called on pointer %lx wo debugging info\n",
         	(unsigned long)p);
         return(GC_realloc(p, lb));
     }
     hhdr = HDR(base);
     switch (hhdr -> hb_obj_kind) {
 #    ifdef STUBBORN_ALLOC
       case STUBBORN:
         result = GC_debug_malloc_stubborn(lb, OPT_RA s, i);
         break;
 #    endif
       case NORMAL:
         result = GC_debug_malloc(lb, OPT_RA s, i);
         break;
       case PTRFREE:
         result = GC_debug_malloc_atomic(lb, OPT_RA s, i);
         break;
       case UNCOLLECTABLE:
 	result = GC_debug_malloc_uncollectable(lb, OPT_RA s, i);
  	break;
 #    ifdef ATOMIC_UNCOLLECTABLE
       case AUNCOLLECTABLE:
 	result = GC_debug_malloc_atomic_uncollectable(lb, OPT_RA s, i);
 	break;
 #    endif
       default:
         GC_err_printf0("GC_debug_realloc: encountered bad kind\n");
         ABORT("bad kind");
     }
     clobbered = GC_check_annotated_obj((oh *)base);
     if (clobbered != 0) {
         GC_err_printf0("GC_debug_realloc: found smashed location at ");
         GC_print_smashed_obj(p, clobbered);
     }
     old_sz = ((oh *)base) -> oh_sz;
     if (old_sz < copy_sz) copy_sz = old_sz;
     if (result == 0) return(0);
     BCOPY(p, result,  copy_sz);
     GC_debug_free(p);
     return(result);
 }

 /* Check all marked objects in the given block for validity */
 /*ARGSUSED*/
 void GC_check_heap_block(hbp, dummy)
 register struct hblk *hbp;	/* ptr to current heap block		*/
 word dummy;
 {
     register struct hblkhdr * hhdr = HDR(hbp);
     register word sz = hhdr -> hb_sz;
     register int word_no;
     register word *p, *plim;

     p = (word *)(hbp->hb_body);
     word_no = HDR_WORDS;
     if (sz > MAXOBJSZ) {
 	plim = p;
     } else {
     	plim = (word *)((((word)hbp) + HBLKSIZE) - WORDS_TO_BYTES(sz));
     }
     /* go through all words in block */
 	while( p <= plim ) {
 	    if( mark_bit_from_hdr(hhdr, word_no)
 	        && GC_has_debug_info((ptr_t)p)) {
 	        ptr_t clobbered = GC_check_annotated_obj((oh *)p);

 	        if (clobbered != 0) {
 	            GC_err_printf0(
 	                "GC_check_heap_block: found smashed location at ");
         	    GC_print_smashed_obj((ptr_t)p, clobbered);
 	        }
 	    }
 	    word_no += sz;
 	    p += sz;
 	}
 }


 /* This assumes that all accessible objects are marked, and that	*/
 /* I hold the allocation lock.	Normally called by collector.		*/
 void GC_check_heap_proc()
 {
 #   ifndef SMALL_CONFIG
 	if (sizeof(oh) & (2 * sizeof(word) - 1) != 0) {
 	    ABORT("Alignment problem: object header has inappropriate size\n");
 	}
 #   endif
     GC_apply_to_all_blocks(GC_check_heap_block, (word)0);
 }

 struct closure {
     GC_finalization_proc cl_fn;
     GC_PTR cl_data;
 };

 # ifdef __STDC__
     void * GC_make_closure(GC_finalization_proc fn, void * data)
 # else
     GC_PTR GC_make_closure(fn, data)
     GC_finalization_proc fn;
     GC_PTR data;
 # endif
 {
     struct closure * result =
     		(struct closure *) GC_malloc(sizeof (struct closure));

     result -> cl_fn = fn;
     result -> cl_data = data;
     return((GC_PTR)result);
 }

 # ifdef __STDC__
     void GC_debug_invoke_finalizer(void * obj, void * data)
 # else
     void GC_debug_invoke_finalizer(obj, data)
     char * obj;
     char * data;
 # endif
 {
     register struct closure * cl = (struct closure *) data;

     (*(cl -> cl_fn))((GC_PTR)((char *)obj + sizeof(oh)), cl -> cl_data);
 }


 # ifdef __STDC__
     void GC_debug_register_finalizer(GC_PTR obj, GC_finalization_proc fn,
     				     GC_PTR cd, GC_finalization_proc *ofn,
 				     GC_PTR *ocd)
 # else
     void GC_debug_register_finalizer(obj, fn, cd, ofn, ocd)
     GC_PTR obj;
     GC_finalization_proc fn;
     GC_PTR cd;
     GC_finalization_proc *ofn;
     GC_PTR *ocd;
 # endif
 {
     ptr_t base = GC_base(obj);
     if (0 == base || (ptr_t)obj - base != sizeof(oh)) {
         GC_err_printf1(
 	    "GC_register_finalizer called with non-base-pointer 0x%lx\n",
 	    obj);
     }
     GC_register_finalizer(base, GC_debug_invoke_finalizer,
     			  GC_make_closure(fn,cd), ofn, ocd);
 }

 # ifdef __STDC__
     void GC_debug_register_finalizer_no_order
     				    (GC_PTR obj, GC_finalization_proc fn,
     				     GC_PTR cd, GC_finalization_proc *ofn,
 				     GC_PTR *ocd)
 # else
     void GC_debug_register_finalizer_no_order
     				    (obj, fn, cd, ofn, ocd)
     GC_PTR obj;
     GC_finalization_proc fn;
     GC_PTR cd;
     GC_finalization_proc *ofn;
     GC_PTR *ocd;
 # endif
 {
     ptr_t base = GC_base(obj);
     if (0 == base || (ptr_t)obj - base != sizeof(oh)) {
         GC_err_printf1(
 	  "GC_register_finalizer_no_order called with non-base-pointer 0x%lx\n",
 	  obj);
     }
     GC_register_finalizer_no_order(base, GC_debug_invoke_finalizer,
      			  	      GC_make_closure(fn,cd), ofn, ocd);
  }

 # ifdef __STDC__
     void GC_debug_register_finalizer_ignore_self
     				    (GC_PTR obj, GC_finalization_proc fn,
     				     GC_PTR cd, GC_finalization_proc *ofn,
 				     GC_PTR *ocd)
 # else
     void GC_debug_register_finalizer_ignore_self
     				    (obj, fn, cd, ofn, ocd)
     GC_PTR obj;
     GC_finalization_proc fn;
     GC_PTR cd;
     GC_finalization_proc *ofn;
     GC_PTR *ocd;
 # endif
 {
     ptr_t base = GC_base(obj);
     if (0 == base || (ptr_t)obj - base != sizeof(oh)) {
         GC_err_printf1(
 	    "GC_register_finalizer_ignore_self called with non-base-pointer 0x%lx\n",
 	    obj);
     }
     GC_register_finalizer_ignore_self(base, GC_debug_invoke_finalizer,
     			  	      GC_make_closure(fn,cd), ofn, ocd);
 }
	/*
	* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
	* Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
	* Copyright (c) 1997 by Silicon Graphics. All rights reserved.
	* Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
	*
	* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
	* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
	*
	* Permission is hereby granted to use or copy this program
	* for any purpose, provided the above notices are retained on all copies.
	* Permission to modify the code and to distribute modified code is granted,
	* provided the above notices are retained, and a notice that the code was
	* modified is included with the above copyright notice.
	*/

	#include "dbg_mlc.h"

	void GC_default_print_heap_obj_proc();
	GC_API void GC_register_finalizer_no_order
	GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
	GC_finalization_proc ofn, GC_PTR ocd));


	/* Check whether object with base pointer p has debugging info */
	/* p is assumed to point to a legitimate object in our part */
	/* of the heap. */
	GC_bool GC_has_debug_info(p)
	ptr_t p;
	{
	register oh * ohdr = (oh *)p;
	register ptr_t body = (ptr_t)(ohdr + 1);
	register word sz = GC_size((ptr_t) ohdr);

	if (HBLKPTR((ptr_t)ohdr) != HBLKPTR((ptr_t)body)
	\|\| sz < sizeof (oh)) {
	return(FALSE);
	}
	if (ohdr -> oh_sz == sz) {
	/* Object may have had debug info, but has been deallocated */
	return(FALSE);
	}
	if (ohdr -> oh_sf == (START_FLAG ^ (word)body)) return(TRUE);
	if (((word *)ohdr)[BYTES_TO_WORDS(sz)-1] == (END_FLAG ^ (word)body)) {
	return(TRUE);
	}
	return(FALSE);
	}

	#ifdef KEEP_BACK_PTRS
	/* Store back pointer to source in dest, if that appears to be possible. */
	/* This is not completely safe, since we may mistakenly conclude that */
	/* dest has a debugging wrapper. But the error probability is very */
	/* small, and this shouldn't be used in production code. */
	/* We assume that dest is the real base pointer. Source will usually */
	/* be a pointer to the interior of an object. */
	void GC_store_back_pointer(ptr_t source, ptr_t dest)
	{
	if (GC_has_debug_info(dest)) {
	((oh *)dest) -> oh_back_ptr = (ptr_t)HIDE_POINTER(source);
	}
	}

	void GC_marked_for_finalization(ptr_t dest) {
	GC_store_back_pointer(MARKED_FOR_FINALIZATION, dest);
	}

	/* Store information about the object referencing dest in base_p /
	/* and offset_p. /
	/* source is root ==> base_p = address, offset_p = 0 */
	/* source is heap object ==> base_p != 0, offset_p = offset */
	/* Returns 1 on success, 0 if source couldn't be determined. */
	/* Dest can be any address within a heap object. */
	GC_ref_kind GC_get_back_ptr_info(void dest, void base_p, size_t offset_p)
	{
	oh * hdr = (oh *)GC_base(dest);
	ptr_t bp;
	ptr_t bp_base;
	if (!GC_has_debug_info((ptr_t) hdr)) return GC_NO_SPACE;
	bp = hdr -> oh_back_ptr;
	if (MARKED_FOR_FINALIZATION == bp) return GC_FINALIZER_REFD;
	if (MARKED_FROM_REGISTER == bp) return GC_REFD_FROM_REG;
	if (0 == bp) return GC_UNREFERENCED;
	bp = REVEAL_POINTER(bp);
	bp_base = GC_base(bp);
	if (0 == bp_base) {
	*base_p = bp;
	*offset_p = 0;
	return GC_REFD_FROM_ROOT;
	} else {
	if (GC_has_debug_info(bp_base)) bp_base += sizeof(oh);
	*base_p = bp_base;
	*offset_p = bp - bp_base;
	return GC_REFD_FROM_HEAP;
	}
	}

	/* Generate a random heap address. */
	/* The resulting address is in the heap, but */
	/* not necessarily inside a valid object. */
	void *GC_generate_random_heap_address(void)
	{
	int i;
	int heap_offset = random() % GC_heapsize;
	for (i = 0; i < GC_n_heap_sects; ++ i) {
	int size = GC_heap_sects[i].hs_bytes;
	if (heap_offset < size) {
	return GC_heap_sects[i].hs_start + heap_offset;
	} else {
	heap_offset -= size;
	}
	}
	ABORT("GC_generate_random_heap_address: size inconsistency");
	/NOTREACHED/
	return 0;
	}

	/* Generate a random address inside a valid marked heap object. */
	void *GC_generate_random_valid_address(void)
	{
	ptr_t result;
	ptr_t base;
	for (;;) {
	result = GC_generate_random_heap_address();
	base = GC_base(result);
	if (0 == base) continue;
	if (!GC_is_marked(base)) continue;
	return result;
	}
	}

	/* Print back trace for p */
	void GC_print_backtrace(void *p)
	{
	void *current = p;
	int i;
	GC_ref_kind source;
	size_t offset;
	void *base;

	GC_print_heap_obj(GC_base(current));
	GC_err_printf0("\n");
	for (i = 0; ; ++i) {
	source = GC_get_back_ptr_info(current, &base, &offset);
	if (GC_UNREFERENCED == source) {
	GC_err_printf0("Reference could not be found\n");
	goto out;
	}
	if (GC_NO_SPACE == source) {
	GC_err_printf0("No debug info in object: Can't find reference\n");
	goto out;
	}
	GC_err_printf1("Reachable via %d levels of pointers from ",
	(unsigned long)i);
	switch(source) {
	case GC_REFD_FROM_ROOT:
	GC_err_printf1("root at 0x%lx\n", (unsigned long)base);
	goto out;
	case GC_REFD_FROM_REG:
	GC_err_printf0("root in register\n");
	goto out;
	case GC_FINALIZER_REFD:
	GC_err_printf0("list of finalizable objects\n");
	goto out;
	case GC_REFD_FROM_HEAP:
	GC_err_printf1("offset %ld in object:\n", (unsigned long)offset);
	/* Take GC_base(base) to get real base, i.e. header. */
	GC_print_heap_obj(GC_base(base));
	GC_err_printf0("\n");
	break;
	}
	current = base;
	}
	out:;
	}

	/* Force a garbage collection and generate a backtrace from a */
	/* random heap address. */
	void GC_generate_random_backtrace(void)
	{
	void * current;
	GC_gcollect();
	current = GC_generate_random_valid_address();
	GC_printf1("Chose address 0x%lx in object\n", (unsigned long)current);
	GC_print_backtrace(current);
	}

	#endif /* KEEP_BACK_PTRS */

	/* Store debugging info into p. Return displaced pointer. */
	/* Assumes we don't hold allocation lock. */
	ptr_t GC_store_debug_info(p, sz, string, integer)
	register ptr_t p; /* base pointer */
	word sz; /* bytes */
	char * string;
	word integer;
	{
	register word * result = (word )((oh )p + 1);
	DCL_LOCK_STATE;

	/* There is some argument that we should dissble signals here. */
	/* But that's expensive. And this way things should only appear */
	/* inconsistent while we're in the handler. */
	LOCK();
	# ifdef KEEP_BACK_PTRS
	((oh *)p) -> oh_back_ptr = 0;
	# endif
	((oh *)p) -> oh_string = string;
	((oh *)p) -> oh_int = integer;
	((oh *)p) -> oh_sz = sz;
	((oh *)p) -> oh_sf = START_FLAG ^ (word)result;
	((word *)p)[BYTES_TO_WORDS(GC_size(p))-1] =
	result[ROUNDED_UP_WORDS(sz)] = END_FLAG ^ (word)result;
	UNLOCK();
	return((ptr_t)result);
	}

	/* Check the object with debugging info at ohdr */
	/* return NIL if it's OK. Else return clobbered */
	/* address. */
	ptr_t GC_check_annotated_obj(ohdr)
	register oh * ohdr;
	{
	register ptr_t body = (ptr_t)(ohdr + 1);
	register word gc_sz = GC_size((ptr_t)ohdr);
	if (ohdr -> oh_sz + DEBUG_BYTES > gc_sz) {
	return((ptr_t)(&(ohdr -> oh_sz)));
	}
	if (ohdr -> oh_sf != (START_FLAG ^ (word)body)) {
	return((ptr_t)(&(ohdr -> oh_sf)));
	}
	if (((word *)ohdr)[BYTES_TO_WORDS(gc_sz)-1] != (END_FLAG ^ (word)body)) {
	return((ptr_t)((word *)ohdr + BYTES_TO_WORDS(gc_sz)-1));
	}
	if (((word *)body)[ROUNDED_UP_WORDS(ohdr -> oh_sz)]
	!= (END_FLAG ^ (word)body)) {
	return((ptr_t)((word *)body + ROUNDED_UP_WORDS(ohdr -> oh_sz)));
	}
	return(0);
	}

	void GC_print_obj(p)
	ptr_t p;
	{
	register oh * ohdr = (oh *)GC_base(p);

	GC_err_printf1("0x%lx (", ((unsigned long)ohdr + sizeof(oh)));
	GC_err_puts(ohdr -> oh_string);
	GC_err_printf2(":%ld, sz=%ld)\n", (unsigned long)(ohdr -> oh_int),
	(unsigned long)(ohdr -> oh_sz));
	PRINT_CALL_CHAIN(ohdr);
	}

	void GC_debug_print_heap_obj_proc(p)
	ptr_t p;
	{
	if (GC_has_debug_info(p)) {
	GC_print_obj(p);
	} else {
	GC_default_print_heap_obj_proc(p);
	}
	}

	void GC_print_smashed_obj(p, clobbered_addr)
	ptr_t p, clobbered_addr;
	{
	register oh * ohdr = (oh *)GC_base(p);

	GC_err_printf2("0x%lx in object at 0x%lx(", (unsigned long)clobbered_addr,
	(unsigned long)p);
	if (clobbered_addr <= (ptr_t)(&(ohdr -> oh_sz))
	\|\| ohdr -> oh_string == 0) {
	GC_err_printf1("<smashed>, appr. sz = %ld)\n",
	(GC_size((ptr_t)ohdr) - DEBUG_BYTES));
	} else {
	if (ohdr -> oh_string[0] == '\0') {
	GC_err_puts("EMPTY(smashed?)");
	} else {
	GC_err_puts(ohdr -> oh_string);
	}
	GC_err_printf2(":%ld, sz=%ld)\n", (unsigned long)(ohdr -> oh_int),
	(unsigned long)(ohdr -> oh_sz));
	PRINT_CALL_CHAIN(ohdr);
	}
	}

	void GC_check_heap_proc();

	void GC_start_debugging()
	{
	GC_check_heap = GC_check_heap_proc;
	GC_print_heap_obj = GC_debug_print_heap_obj_proc;
	GC_debugging_started = TRUE;
	GC_register_displacement((word)sizeof(oh));
	}

	# if defined(__STDC__) \|\| defined(__cplusplus)
	void GC_debug_register_displacement(GC_word offset)
	# else
	void GC_debug_register_displacement(offset)
	GC_word offset;
	# endif
	{
	GC_register_displacement(offset);
	GC_register_displacement((word)sizeof(oh) + offset);
	}

	# ifdef __STDC__
	GC_PTR GC_debug_malloc(size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc(lb, s, i)
	size_t lb;
	char * s;
	int i;
	# ifdef GC_ADD_CALLER
	--> GC_ADD_CALLER not implemented for K&R C
	# endif
	# endif
	{
	GC_PTR result = GC_malloc(lb + DEBUG_BYTES);

	if (result == 0) {
	GC_err_printf1("GC_debug_malloc(%ld) returning NIL (",
	(unsigned long) lb);
	GC_err_puts(s);
	GC_err_printf1(":%ld)\n", (unsigned long)i);
	return(0);
	}
	if (!GC_debugging_started) {
	GC_start_debugging();
	}
	ADD_CALL_CHAIN(result, ra);
	return (GC_store_debug_info(result, (word)lb, s, (word)i));
	}

	# ifdef __STDC__
	GC_PTR GC_debug_generic_malloc(size_t lb, int k, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc(lb, k, s, i)
	size_t lb;
	int k;
	char * s;
	int i;
	# ifdef GC_ADD_CALLER
	--> GC_ADD_CALLER not implemented for K&R C
	# endif
	# endif
	{
	GC_PTR result = GC_generic_malloc(lb + DEBUG_BYTES, k);

	if (result == 0) {
	GC_err_printf1("GC_debug_malloc(%ld) returning NIL (",
	(unsigned long) lb);
	GC_err_puts(s);
	GC_err_printf1(":%ld)\n", (unsigned long)i);
	return(0);
	}
	if (!GC_debugging_started) {
	GC_start_debugging();
	}
	ADD_CALL_CHAIN(result, ra);
	return (GC_store_debug_info(result, (word)lb, s, (word)i));
	}

	#ifdef STUBBORN_ALLOC
	# ifdef __STDC__
	GC_PTR GC_debug_malloc_stubborn(size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc_stubborn(lb, s, i)
	size_t lb;
	char * s;
	int i;
	# endif
	{
	GC_PTR result = GC_malloc_stubborn(lb + DEBUG_BYTES);

	if (result == 0) {
	GC_err_printf1("GC_debug_malloc(%ld) returning NIL (",
	(unsigned long) lb);
	GC_err_puts(s);
	GC_err_printf1(":%ld)\n", (unsigned long)i);
	return(0);
	}
	if (!GC_debugging_started) {
	GC_start_debugging();
	}
	ADD_CALL_CHAIN(result, ra);
	return (GC_store_debug_info(result, (word)lb, s, (word)i));
	}

	void GC_debug_change_stubborn(p)
	GC_PTR p;
	{
	register GC_PTR q = GC_base(p);
	register hdr * hhdr;

	if (q == 0) {
	GC_err_printf1("Bad argument: 0x%lx to GC_debug_change_stubborn\n",
	(unsigned long) p);
	ABORT("GC_debug_change_stubborn: bad arg");
	}
	hhdr = HDR(q);
	if (hhdr -> hb_obj_kind != STUBBORN) {
	GC_err_printf1("GC_debug_change_stubborn arg not stubborn: 0x%lx\n",
	(unsigned long) p);
	ABORT("GC_debug_change_stubborn: arg not stubborn");
	}
	GC_change_stubborn(q);
	}

	void GC_debug_end_stubborn_change(p)
	GC_PTR p;
	{
	register GC_PTR q = GC_base(p);
	register hdr * hhdr;

	if (q == 0) {
	GC_err_printf1("Bad argument: 0x%lx to GC_debug_end_stubborn_change\n",
	(unsigned long) p);
	ABORT("GC_debug_end_stubborn_change: bad arg");
	}
	hhdr = HDR(q);
	if (hhdr -> hb_obj_kind != STUBBORN) {
	GC_err_printf1("debug_end_stubborn_change arg not stubborn: 0x%lx\n",
	(unsigned long) p);
	ABORT("GC_debug_end_stubborn_change: arg not stubborn");
	}
	GC_end_stubborn_change(q);
	}

	#else /* !STUBBORN_ALLOC */

	# ifdef __STDC__
	GC_PTR GC_debug_malloc_stubborn(size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc_stubborn(lb, s, i)
	size_t lb;
	char * s;
	int i;
	# endif
	{
	return GC_debug_malloc(lb, OPT_RA s, i);
	}

	void GC_debug_change_stubborn(p)
	GC_PTR p;
	{
	}

	void GC_debug_end_stubborn_change(p)
	GC_PTR p;
	{
	}

	#endif /* !STUBBORN_ALLOC */

	# ifdef __STDC__
	GC_PTR GC_debug_malloc_atomic(size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc_atomic(lb, s, i)
	size_t lb;
	char * s;
	int i;
	# endif
	{
	GC_PTR result = GC_malloc_atomic(lb + DEBUG_BYTES);

	if (result == 0) {
	GC_err_printf1("GC_debug_malloc_atomic(%ld) returning NIL (",
	(unsigned long) lb);
	GC_err_puts(s);
	GC_err_printf1(":%ld)\n", (unsigned long)i);
	return(0);
	}
	if (!GC_debugging_started) {
	GC_start_debugging();
	}
	ADD_CALL_CHAIN(result, ra);
	return (GC_store_debug_info(result, (word)lb, s, (word)i));
	}

	# ifdef __STDC__
	GC_PTR GC_debug_malloc_uncollectable(size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc_uncollectable(lb, s, i)
	size_t lb;
	char * s;
	int i;
	# endif
	{
	GC_PTR result = GC_malloc_uncollectable(lb + DEBUG_BYTES);

	if (result == 0) {
	GC_err_printf1("GC_debug_malloc_uncollectable(%ld) returning NIL (",
	(unsigned long) lb);
	GC_err_puts(s);
	GC_err_printf1(":%ld)\n", (unsigned long)i);
	return(0);
	}
	if (!GC_debugging_started) {
	GC_start_debugging();
	}
	ADD_CALL_CHAIN(result, ra);
	return (GC_store_debug_info(result, (word)lb, s, (word)i));
	}

	#ifdef ATOMIC_UNCOLLECTABLE
	# ifdef __STDC__
	GC_PTR GC_debug_malloc_atomic_uncollectable(size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_malloc_atomic_uncollectable(lb, s, i)
	size_t lb;
	char * s;
	int i;
	# endif
	{
	GC_PTR result = GC_malloc_atomic_uncollectable(lb + DEBUG_BYTES);

	if (result == 0) {
	GC_err_printf1(
	"GC_debug_malloc_atomic_uncollectable(%ld) returning NIL (",
	(unsigned long) lb);
	GC_err_puts(s);
	GC_err_printf1(":%ld)\n", (unsigned long)i);
	return(0);
	}
	if (!GC_debugging_started) {
	GC_start_debugging();
	}
	ADD_CALL_CHAIN(result, ra);
	return (GC_store_debug_info(result, (word)lb, s, (word)i));
	}
	#endif /* ATOMIC_UNCOLLECTABLE */

	# ifdef __STDC__
	void GC_debug_free(GC_PTR p)
	# else
	void GC_debug_free(p)
	GC_PTR p;
	# endif
	{
	register GC_PTR base;
	register ptr_t clobbered;

	if (0 == p) return;
	base = GC_base(p);
	if (base == 0) {
	GC_err_printf1("Attempt to free invalid pointer %lx\n",
	(unsigned long)p);
	ABORT("free(invalid pointer)");
	}
	if ((ptr_t)p - (ptr_t)base != sizeof(oh)) {
	GC_err_printf1(
	"GC_debug_free called on pointer %lx wo debugging info\n",
	(unsigned long)p);
	} else {
	clobbered = GC_check_annotated_obj((oh *)base);
	if (clobbered != 0) {
	if (((oh *)base) -> oh_sz == GC_size(base)) {
	GC_err_printf0(
	"GC_debug_free: found previously deallocated (?) object at ");
	} else {
	GC_err_printf0("GC_debug_free: found smashed location at ");
	}
	GC_print_smashed_obj(p, clobbered);
	}
	/* Invalidate size */
	((oh *)base) -> oh_sz = GC_size(base);
	}
	if (GC_find_leak) {
	GC_free(base);
	} else {
	register hdr * hhdr = HDR(p);
	GC_bool uncollectable = FALSE;

	if (hhdr -> hb_obj_kind == UNCOLLECTABLE) {
	uncollectable = TRUE;
	}
	# ifdef ATOMIC_UNCOLLECTABLE
	if (hhdr -> hb_obj_kind == AUNCOLLECTABLE) {
	uncollectable = TRUE;
	}
	# endif
	if (uncollectable) GC_free(base);
	} /* !GC_find_leak */
	}

	# ifdef __STDC__
	GC_PTR GC_debug_realloc(GC_PTR p, size_t lb, GC_EXTRA_PARAMS)
	# else
	GC_PTR GC_debug_realloc(p, lb, s, i)
	GC_PTR p;
	size_t lb;
	char *s;
	int i;
	# endif
	{
	register GC_PTR base = GC_base(p);
	register ptr_t clobbered;
	register GC_PTR result;
	register size_t copy_sz = lb;
	register size_t old_sz;
	register hdr * hhdr;

	if (p == 0) return(GC_debug_malloc(lb, OPT_RA s, i));
	if (base == 0) {
	GC_err_printf1(
	"Attempt to reallocate invalid pointer %lx\n", (unsigned long)p);
	ABORT("realloc(invalid pointer)");
	}
	if ((ptr_t)p - (ptr_t)base != sizeof(oh)) {
	GC_err_printf1(
	"GC_debug_realloc called on pointer %lx wo debugging info\n",
	(unsigned long)p);
	return(GC_realloc(p, lb));
	}
	hhdr = HDR(base);
	switch (hhdr -> hb_obj_kind) {
	# ifdef STUBBORN_ALLOC
	case STUBBORN:
	result = GC_debug_malloc_stubborn(lb, OPT_RA s, i);
	break;
	# endif
	case NORMAL:
	result = GC_debug_malloc(lb, OPT_RA s, i);
	break;
	case PTRFREE:
	result = GC_debug_malloc_atomic(lb, OPT_RA s, i);
	break;
	case UNCOLLECTABLE:
	result = GC_debug_malloc_uncollectable(lb, OPT_RA s, i);
	break;
	# ifdef ATOMIC_UNCOLLECTABLE
	case AUNCOLLECTABLE:
	result = GC_debug_malloc_atomic_uncollectable(lb, OPT_RA s, i);
	break;
	# endif
	default:
	GC_err_printf0("GC_debug_realloc: encountered bad kind\n");
	ABORT("bad kind");
	}
	clobbered = GC_check_annotated_obj((oh *)base);
	if (clobbered != 0) {
	GC_err_printf0("GC_debug_realloc: found smashed location at ");
	GC_print_smashed_obj(p, clobbered);
	}
	old_sz = ((oh *)base) -> oh_sz;
	if (old_sz < copy_sz) copy_sz = old_sz;
	if (result == 0) return(0);
	BCOPY(p, result, copy_sz);
	GC_debug_free(p);
	return(result);
	}

	/* Check all marked objects in the given block for validity */
	/ARGSUSED/
	void GC_check_heap_block(hbp, dummy)
	register struct hblk hbp; / ptr to current heap block */
	word dummy;
	{
	register struct hblkhdr * hhdr = HDR(hbp);
	register word sz = hhdr -> hb_sz;
	register int word_no;
	register word p, plim;

	p = (word *)(hbp->hb_body);
	word_no = HDR_WORDS;
	if (sz > MAXOBJSZ) {
	plim = p;
	} else {
	plim = (word *)((((word)hbp) + HBLKSIZE) - WORDS_TO_BYTES(sz));
	}
	/* go through all words in block */
	while( p <= plim ) {
	if( mark_bit_from_hdr(hhdr, word_no)
	&& GC_has_debug_info((ptr_t)p)) {
	ptr_t clobbered = GC_check_annotated_obj((oh *)p);

	if (clobbered != 0) {
	GC_err_printf0(
	"GC_check_heap_block: found smashed location at ");
	GC_print_smashed_obj((ptr_t)p, clobbered);
	}
	}
	word_no += sz;
	p += sz;
	}
	}


	/* This assumes that all accessible objects are marked, and that */
	/* I hold the allocation lock. Normally called by collector. */
	void GC_check_heap_proc()
	{
	# ifndef SMALL_CONFIG
	if (sizeof(oh) & (2 * sizeof(word) - 1) != 0) {
	ABORT("Alignment problem: object header has inappropriate size\n");
	}
	# endif
	GC_apply_to_all_blocks(GC_check_heap_block, (word)0);
	}

	struct closure {
	GC_finalization_proc cl_fn;
	GC_PTR cl_data;
	};

	# ifdef __STDC__
	void * GC_make_closure(GC_finalization_proc fn, void * data)
	# else
	GC_PTR GC_make_closure(fn, data)
	GC_finalization_proc fn;
	GC_PTR data;
	# endif
	{
	struct closure * result =
	(struct closure *) GC_malloc(sizeof (struct closure));

	result -> cl_fn = fn;
	result -> cl_data = data;
	return((GC_PTR)result);
	}

	# ifdef __STDC__
	void GC_debug_invoke_finalizer(void * obj, void * data)
	# else
	void GC_debug_invoke_finalizer(obj, data)
	char * obj;
	char * data;
	# endif
	{
	register struct closure * cl = (struct closure *) data;

	((cl -> cl_fn))((GC_PTR)((char )obj + sizeof(oh)), cl -> cl_data);
	}


	# ifdef __STDC__
	void GC_debug_register_finalizer(GC_PTR obj, GC_finalization_proc fn,
	GC_PTR cd, GC_finalization_proc *ofn,
	GC_PTR *ocd)
	# else
	void GC_debug_register_finalizer(obj, fn, cd, ofn, ocd)
	GC_PTR obj;
	GC_finalization_proc fn;
	GC_PTR cd;
	GC_finalization_proc *ofn;
	GC_PTR *ocd;
	# endif
	{
	ptr_t base = GC_base(obj);
	if (0 == base \|\| (ptr_t)obj - base != sizeof(oh)) {
	GC_err_printf1(
	"GC_register_finalizer called with non-base-pointer 0x%lx\n",
	obj);
	}
	GC_register_finalizer(base, GC_debug_invoke_finalizer,
	GC_make_closure(fn,cd), ofn, ocd);
	}

	# ifdef __STDC__
	void GC_debug_register_finalizer_no_order
	(GC_PTR obj, GC_finalization_proc fn,
	GC_PTR cd, GC_finalization_proc *ofn,
	GC_PTR *ocd)
	# else
	void GC_debug_register_finalizer_no_order
	(obj, fn, cd, ofn, ocd)
	GC_PTR obj;
	GC_finalization_proc fn;
	GC_PTR cd;
	GC_finalization_proc *ofn;
	GC_PTR *ocd;
	# endif
	{
	ptr_t base = GC_base(obj);
	if (0 == base \|\| (ptr_t)obj - base != sizeof(oh)) {
	GC_err_printf1(
	"GC_register_finalizer_no_order called with non-base-pointer 0x%lx\n",
	obj);
	}
	GC_register_finalizer_no_order(base, GC_debug_invoke_finalizer,
	GC_make_closure(fn,cd), ofn, ocd);
	}

	# ifdef __STDC__
	void GC_debug_register_finalizer_ignore_self
	(GC_PTR obj, GC_finalization_proc fn,
	GC_PTR cd, GC_finalization_proc *ofn,
	GC_PTR *ocd)
	# else
	void GC_debug_register_finalizer_ignore_self
	(obj, fn, cd, ofn, ocd)
	GC_PTR obj;
	GC_finalization_proc fn;
	GC_PTR cd;
	GC_finalization_proc *ofn;
	GC_PTR *ocd;
	# endif
	{
	ptr_t base = GC_base(obj);
	if (0 == base \|\| (ptr_t)obj - base != sizeof(oh)) {
	GC_err_printf1(
	"GC_register_finalizer_ignore_self called with non-base-pointer 0x%lx\n",
	obj);
	}
	GC_register_finalizer_ignore_self(base, GC_debug_invoke_finalizer,
	GC_make_closure(fn,cd), ofn, ocd);
	}