Ticket #717: fake_string_newline_optimization.patch

src/io/api.c

@@ -319 +319 @@
     if (PMC_IS_NULL(pmc))
         return -1;
 
+    /* There is a GC issue with using the fake STRING.
+     * However, it would be a performance drain to use Parrot_str_new for each call.
+     * For now, optimize for "\n", which will remove the GC issue during the execution
+     * of `say 'constant'`.
+     */
+    if (length == 1 && ((const char *)buffer)[0] == '\n') {
+        result = Parrot_io_putps(interp, pmc, CONST_STRING(interp, "\n"));
+        return result;
+    }
+
     fake.strstart = (char *) PARROT_const_cast(void *, buffer);
     fake.strlen = fake.bufused = length;
     fake.charset = Parrot_default_charset_ptr;