- /* If it's not a return address then it needs to be a valid Lisp
- * pointer. */
- if (!is_lisp_pointer((lispobj)pointer)) {
- return 0;
- }
-
- /* Check that the object pointed to is consistent with the pointer
- * low tag.
- */
- switch (lowtag_of((lispobj)pointer)) {
- case FUN_POINTER_LOWTAG:
- /* Start_addr should be the enclosing code object, or a closure
- * header. */
- switch (widetag_of(*start_addr)) {
- case CODE_HEADER_WIDETAG:
- /* This case is probably caught above. */
- break;
- case CLOSURE_HEADER_WIDETAG:
- case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
- if ((unsigned)pointer !=
- ((unsigned)start_addr+FUN_POINTER_LOWTAG)) {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wf2: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- break;
- default:
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wf3: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- break;
- case LIST_POINTER_LOWTAG:
- if ((unsigned)pointer !=
- ((unsigned)start_addr+LIST_POINTER_LOWTAG)) {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wl1: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- /* Is it plausible cons? */
- if ((is_lisp_pointer(start_addr[0])
- || (fixnump(start_addr[0]))
- || (widetag_of(start_addr[0]) == CHARACTER_WIDETAG)
-#if N_WORD_BITS == 64
- || (widetag_of(start_addr[0]) == SINGLE_FLOAT_WIDETAG)
-#endif
- || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
- && (is_lisp_pointer(start_addr[1])
- || (fixnump(start_addr[1]))
- || (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
-#if N_WORD_BITS == 64
- || (widetag_of(start_addr[1]) == SINGLE_FLOAT_WIDETAG)
-#endif
- || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG)))
- break;
- else {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wl2: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- case INSTANCE_POINTER_LOWTAG:
- if ((unsigned)pointer !=
- ((unsigned)start_addr+INSTANCE_POINTER_LOWTAG)) {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wi1: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wi2: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- break;
- case OTHER_POINTER_LOWTAG:
- if ((unsigned)pointer !=
- ((int)start_addr+OTHER_POINTER_LOWTAG)) {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wo1: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- /* Is it plausible? Not a cons. XXX should check the headers. */
- if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wo2: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- switch (widetag_of(start_addr[0])) {
- case UNBOUND_MARKER_WIDETAG:
- case CHARACTER_WIDETAG:
-#if N_WORD_BITS == 64
- case SINGLE_FLOAT_WIDETAG:
-#endif
- if (gencgc_verbose)
- FSHOW((stderr,
- "*Wo3: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
-
- /* only pointed to by function pointers? */
- case CLOSURE_HEADER_WIDETAG:
- case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
- if (gencgc_verbose)
- FSHOW((stderr,
- "*Wo4: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
-
- case INSTANCE_HEADER_WIDETAG:
- if (gencgc_verbose)
- FSHOW((stderr,
- "*Wo5: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
-
- /* the valid other immediate pointer objects */
- case SIMPLE_VECTOR_WIDETAG:
- case RATIO_WIDETAG:
- case COMPLEX_WIDETAG:
-#ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
- case COMPLEX_SINGLE_FLOAT_WIDETAG:
-#endif
-#ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
- case COMPLEX_DOUBLE_FLOAT_WIDETAG:
-#endif
-#ifdef COMPLEX_LONG_FLOAT_WIDETAG
- case COMPLEX_LONG_FLOAT_WIDETAG:
-#endif
- case SIMPLE_ARRAY_WIDETAG:
- case COMPLEX_BASE_STRING_WIDETAG:
-#ifdef COMPLEX_CHARACTER_STRING_WIDETAG
- case COMPLEX_CHARACTER_STRING_WIDETAG:
-#endif
- case COMPLEX_VECTOR_NIL_WIDETAG:
- case COMPLEX_BIT_VECTOR_WIDETAG:
- case COMPLEX_VECTOR_WIDETAG:
- case COMPLEX_ARRAY_WIDETAG:
- case VALUE_CELL_HEADER_WIDETAG:
- case SYMBOL_HEADER_WIDETAG:
- case FDEFN_WIDETAG:
- case CODE_HEADER_WIDETAG:
- case BIGNUM_WIDETAG:
-#if N_WORD_BITS != 64
- case SINGLE_FLOAT_WIDETAG:
-#endif
- case DOUBLE_FLOAT_WIDETAG:
-#ifdef LONG_FLOAT_WIDETAG
- case LONG_FLOAT_WIDETAG:
-#endif
- case SIMPLE_BASE_STRING_WIDETAG:
-#ifdef SIMPLE_CHARACTER_STRING_WIDETAG
- case SIMPLE_CHARACTER_STRING_WIDETAG:
-#endif
- case SIMPLE_BIT_VECTOR_WIDETAG:
- case SIMPLE_ARRAY_NIL_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
-#endif
- case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
-#endif
- case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
- case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
-#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
- case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
- case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
- case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
- case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
-#endif
- case SAP_WIDETAG:
- case WEAK_POINTER_WIDETAG:
- break;
-
- default:
- if (gencgc_verbose)
- FSHOW((stderr,
- "/Wo6: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
- break;
- default:
- if (gencgc_verbose)
- FSHOW((stderr,
- "*W?: %x %x %x\n",
- pointer, start_addr, *start_addr));
- return 0;
- }
-
- /* looks good */
- return 1;