[DFSan] Add strpbrk wrapper.

[vitalybuka]

compiler-rt/lib/dfsan/dfsan_custom.cpp

107

[morehouse]

• Simplify ternary.

compiler-rt/lib/dfsan/dfsan_custom.cpp

if (s[i] == c || s[i] == 0) {
       if (s[i] == 0 && c != 0) {
         return nullptr;
       }
       return const_cast<char *>(s + i);
     }
   }
 }
 
+SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strpbrk(const char *s,
+                                                   const char *accept,
+                                                   dfsan_label s_label,
+                                                   dfsan_label accept_label,
+                                                   dfsan_label *ret_label) {
+  const char *ret = strpbrk(s, accept);
+  if (flags().strict_data_dependencies) {
+    *ret_label = ret ? s_label : 0;
+  } else {
+    size_t s_bytes_read = ret ? ret - s + 1 : strlen(s) + 1;
+    *ret_label =
+        dfsan_union(dfsan_read_label(s, s_bytes_read),
+                    dfsan_union(dfsan_read_label(accept, strlen(accept) + 1),
+                                dfsan_union(s_label, accept_label)));
+  }
+  return const_cast<char *>(ret);
+}
+
 static int dfsan_memcmp_bcmp(const void *s1, const void *s2, size_t n,
                              dfsan_label s1_label, dfsan_label s2_label,
                              dfsan_label n_label, dfsan_label *ret_label) {
   const char *cs1 = (const char *) s1, *cs2 = (const char *) s2;
   for (size_t i = 0; i != n; ++i) {
     if (cs1[i] != cs2[i]) {
       if (flags().strict_data_dependencies) {
         *ret_label = 0;

compiler-rt/lib/dfsan/done_abilist.txt

 fun:memchr=custom
 fun:memcmp=custom
 fun:strcasecmp=custom
 fun:strchr=custom
 fun:strcmp=custom
 fun:strlen=custom
 fun:strncasecmp=custom
 fun:strncmp=custom
+fun:strpbrk=custom
 fun:strrchr=custom
 fun:strstr=custom
 
 # Functions which take action based on global state, such as running a callback
 # set by a sepperate function.
 fun:write=custom
 
 # Functions that take a callback (wrap the callback manually).

compiler-rt/test/dfsan/custom.cpp

#endif
   assert(rv == NULL);
 #ifdef STRICT_DATA_DEPENDENCIES
   ASSERT_ZERO_LABEL(rv);
 #else
   ASSERT_LABEL(rv, i_j_label);
 #endif
 }
 
+void test_strpbrk() {
+  char s[] = "abcdefg";
+  char accept[] = "123fd";
+  dfsan_set_label(i_label, &s[5], 1);
+  dfsan_set_label(j_label, &accept[1], 1);
+
+  char *rv = strpbrk(s, accept);
+  assert(rv == &s[3]);
+#ifdef STRICT_DATA_DEPENDENCIES
+  ASSERT_ZERO_LABEL(rv);
+#else
+  ASSERT_LABEL(rv, j_label);
+#endif
+
+  char *ps = s;
+  dfsan_set_label(j_label, &ps, sizeof(ps));
+
+  rv = strpbrk(ps, "123gf");
+  assert(rv == &s[5]);
+#ifdef STRICT_DATA_DEPENDENCIES
+  ASSERT_LABEL(rv, j_label);
+#else
+  ASSERT_LABEL(rv, i_j_label);
+#endif
+
+  rv = strpbrk(ps, "123");
+  assert(rv == NULL);
+#ifdef STRICT_DATA_DEPENDENCIES
+  ASSERT_ZERO_LABEL(rv);
+#else
+  ASSERT_LABEL(rv, i_j_label);
+#endif
+}
+
 void test_memchr() {
   char str1[] = "str1";
   dfsan_set_label(i_label, &str1[3], 1);
   dfsan_set_label(j_label, &str1[4], 1);
 
   char *crv = (char *) memchr(str1, 'r', sizeof(str1));
   assert(crv == &str1[2]);
   ASSERT_ZERO_LABEL(crv);
#endif
   test_strchr();
   test_strcmp();
   test_strcpy();
   test_strdup();
   test_strlen();
   test_strncasecmp();
   test_strncmp();
   test_strncpy();
+  test_strpbrk();
   test_strrchr();
   test_strstr();
   test_strtod();
   test_strtol();
   test_strtoll();
   test_strtoul();
   test_strtoull();
   test_time();
   test_write();
 }