GC_INNER void GC_cond_register_dynamic_libraries(void)
{
# if defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE) \
|| defined(CYGWIN32) || defined(PCR)
GC_remove_tmp_roots();
if (!GC_no_dls) GC_register_dynamic_libraries();
# else
GC_no_dls = TRUE;
# endif
}
/* Currently useless for multithreaded worlds. */
GC_API void * GC_CALL GC_is_visible(void *p)
{
hdr *hhdr;
if ((word)p & (ALIGNMENT - 1)) goto fail;
if (!GC_is_initialized) GC_init();
# ifdef THREADS
hhdr = HDR((word)p);
if (hhdr != 0 && GC_base(p) == 0) {
goto fail;
} else {
/* May be inside thread stack. We can't do much. */
return(p);
}
# else
/* Check stack first: */
if (GC_on_stack(p)) return(p);
hhdr = HDR((word)p);
if (hhdr == 0) {
if (GC_is_static_root(p)) return(p);
/* Else do it again correctly: */
# if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || \
defined(MSWINCE) || defined(PCR))
GC_register_dynamic_libraries();
if (GC_is_static_root(p))
return(p);
# endif
goto fail;
} else {
/* p points to the heap. */
word descr;
ptr_t base = GC_base(p); /* Should be manually inlined? */
if (base == 0) goto fail;
if (HBLKPTR(base) != HBLKPTR(p)) hhdr = HDR((word)p);
descr = hhdr -> hb_descr;
retry:
switch(descr & GC_DS_TAGS) {
case GC_DS_LENGTH:
if ((word)((ptr_t)p - (ptr_t)base) > (word)descr) goto fail;
break;
case GC_DS_BITMAP:
if ((ptr_t)p - (ptr_t)base
>= WORDS_TO_BYTES(BITMAP_BITS)
|| ((word)p & (sizeof(word) - 1))) goto fail;
if (!(((word)1 << (WORDSZ - ((ptr_t)p - (ptr_t)base) - 1))
& descr)) goto fail;
break;
case GC_DS_PROC:
/* We could try to decipher this partially. */
/* For now we just punt. */
break;
case GC_DS_PER_OBJECT:
if ((signed_word)descr >= 0) {
descr = *(word *)((ptr_t)base + (descr & ~GC_DS_TAGS));
} else {
ptr_t type_descr = *(ptr_t *)base;
descr = *(word *)(type_descr
- (descr - (GC_DS_PER_OBJECT
- GC_INDIR_PER_OBJ_BIAS)));
}
goto retry;
}
return(p);
}
# endif
fail:
(*GC_is_visible_print_proc)((ptr_t)p);
return(p);
}
