src/runtime/search.c

   1 /*
   2  * This software is part of the SBCL system. See the README file for
   3  * more information.
   4  *
   5  * This software is derived from the CMU CL system, which was
   6  * written at Carnegie Mellon University and released into the
   7  * public domain. The software is in the public domain and is
   8  * provided with absolutely no warranty. See the COPYING and CREDITS
   9  * files for more information.
  10  */
  11
  12 #include <string.h>
  13
  14 #include "sbcl.h"
  15 #include "runtime.h"
  16 #include "os.h"
  17 #include "search.h"
  18 #include "thread.h"
  19 #include "gc-internal.h"
  20 #include "genesis/primitive-objects.h"
  21
  22 boolean search_for_type(int type, lispobj **start, int *count)
  23 {
  24     lispobj obj;
  25
  26     while ((*count == -1 || (*count > 0)) &&
  27            is_valid_lisp_addr((os_vm_address_t)*start)) {
  28         obj = **start;
  29         if (*count != -1)
  30             *count -= 2;
  31
  32         if (widetag_of(obj) == type)
  33             return 1;
  34
  35         (*start) += 2;
  36     }
  37     return 0;
  38 }
  39
  40 static int __attribute__((unused)) strcmp_ucs4_ascii(uint32_t* a, char* b)
  41 {
  42   int i = 0;
  43
  44   // Lisp terminates UCS4 strings with NULL bytes - probably to no avail
  45   // since null-terminated UCS4 isn't a common convention for any foreign ABI -
  46   // but length has been pre-checked, so hitting an ASCII null is a win.
  47   while (a[i] == ((unsigned char*)b)[i])
  48     if (b[i] == 0)
  49       return 0;
  50     else
  51       ++i;
  52   return a[i] - b[i]; // same return convention as strcmp()
  53 }
  54
  55 lispobj* search_for_symbol(char *name, lispobj start, lispobj end)
  56 {
  57     lispobj* where = (lispobj*)start;
  58     lispobj* limit = (lispobj*)end;
  59     struct symbol *symbol;
  60     int namelen = strlen(name);
  61
  62     while (where < limit) {
  63         lispobj word = *where;
  64         if (widetag_of(word) == SYMBOL_WIDETAG &&
  65             lowtag_of((symbol = (struct symbol *)where)->name)
  66             == OTHER_POINTER_LOWTAG) {
  67             struct vector *symbol_name = VECTOR(symbol->name);
  68             if (is_valid_lisp_addr((os_vm_address_t)symbol_name) &&
  69                 /* FIXME: Broken with more than one type of string
  70                    (i.e. even broken given (VECTOR NIL) */
  71                 ((widetag_of(symbol_name->header) == SIMPLE_BASE_STRING_WIDETAG
  72                   && fixnum_value(symbol_name->length) == namelen
  73                   && !strcmp((char *)symbol_name->data, name))
  74 #ifdef LISP_FEATURE_SB_UNICODE
  75                  || (widetag_of(symbol_name->header) == SIMPLE_CHARACTER_STRING_WIDETAG
  76                      && fixnum_value(symbol_name->length) == namelen
  77                      && !strcmp_ucs4_ascii((uint32_t*)symbol_name->data, name))
  78 #endif
  79                  ))
  80                 return where;
  81         }
  82         where += is_cons_half(word) ? 2 : sizetab[widetag_of(word)](where);
  83     }
  84     return 0;
  85 }