+
+\f
+/* Find the code object for the given pc, or return NULL on
+ failure. */
+lispobj *
+component_ptr_from_pc(lispobj *pc)
+{
+ lispobj *object = NULL;
+
+ if ( (object = search_read_only_space(pc)) )
+ ;
+ else if ( (object = search_static_space(pc)) )
+ ;
+ else
+ object = search_dynamic_space(pc);
+
+ if (object) /* if we found something */
+ if (widetag_of(*object) == CODE_HEADER_WIDETAG)
+ return(object);
+
+ return (NULL);
+}
+
+/* Scan an area looking for an object which encloses the given pointer.
+ * Return the object start on success or NULL on failure. */
+lispobj *
+gc_search_space(lispobj *start, size_t words, lispobj *pointer)
+{
+ while (words > 0) {
+ size_t count = 1;
+ lispobj thing = *start;
+
+ /* If thing is an immediate then this is a cons. */
+ if (is_lisp_pointer(thing)
+ || (fixnump(thing))
+ || (widetag_of(thing) == CHARACTER_WIDETAG)
+#if N_WORD_BITS == 64
+ || (widetag_of(thing) == SINGLE_FLOAT_WIDETAG)
+#endif
+ || (widetag_of(thing) == UNBOUND_MARKER_WIDETAG))
+ count = 2;
+ else
+ count = (sizetab[widetag_of(thing)])(start);
+
+ /* Check whether the pointer is within this object. */
+ if ((pointer >= start) && (pointer < (start+count))) {
+ /* found it! */
+ /*FSHOW((stderr,"/found %x in %x %x\n", pointer, start, thing));*/
+ return(start);
+ }
+
+ /* Round up the count. */
+ count = CEILING(count,2);
+
+ start += count;
+ words -= count;
+ }
+ return (NULL);
+}