+const char *concat_strings(const char *s1, const char *s2)
+{
+ size_t len1 = strlen(s1);
+ size_t len2 = strlen(s2);
+
+ char *concat = obstack_alloc(&symbol_obstack, len1 + len2 + 1);
+ memcpy(concat, s1, len1);
+ memcpy(concat + len1, s2, len2 + 1);
+
+ const char *result = strset_insert(&stringset, concat);
+ if(result != concat) {
+ obstack_free(&symbol_obstack, concat);
+ }
+
+ return result;
+}
+