MRB_FUNCALL_ARGC_MAX support. (refs comments in #324).

include/mrbconf.h

@@ -23,6 +23,10 @@
 
 #undef  HAVE_UNISTD_H /* WINDOWS */
 #define HAVE_UNISTD_H /* LINUX */
+
+#define MRB_FUNCALL_ARGC_MAX 16U /* Allocate arrays using auto variable. */
+//#undef MRB_FUNCALL_ARGC_MAX /* Allocate arrays using mrb_malloc if undefned. */
+
 /* end of configuration */
 
 #ifdef MRB_USE_FLOAT

src/class.c

@@ -7,7 +7,6 @@
 #include "mruby.h"
 #include <stdarg.h>
 #include <stdio.h>
-#include <assert.h>
 #include "mruby/class.h"
 #include "mruby/proc.h"
 #include "mruby/string.h"
@@ -866,27 +865,38 @@ mrb_method_search(mrb_state *mrb, struct RClass* c, mrb_sym mid)
 mrb_value
 mrb_funcall(mrb_state *mrb, mrb_value self, const char *name, int argc, ...)
 {
-  mrb_value *args;
+#if defined(MRB_FUNCALL_ARGC_MAX)
+  mrb_value args[MRB_FUNCALL_ARGC_MAX];
+#else
+  mrb_value *args = NULL;
+#endif
   mrb_value result;
   va_list ap;
   int i;
 
   if (argc != 0) {
+#if !defined(MRB_FUNCALL_ARGC_MAX)
     args = mrb_malloc(mrb, sizeof(mrb_value) * argc);
-    assert(args != 0);
+#else
+    if (argc > MRB_FUNCALL_ARGC_MAX) {
+      mrb_raise(mrb, E_ARGUMENT_ERROR, "Too long arguments. (limit=%d)\n", MRB_FUNCALL_ARGC_MAX);
+    } 
+#endif
 
     va_start(ap, argc);
     for (i = 0; i < argc; i++) {
       args[i] = va_arg(ap, mrb_value);
     }
     va_end(ap);
-  } else {
-    args = NULL;
   }
+
   result = mrb_funcall_argv(mrb, self, name, argc, args);
+
+#if !defined(MRB_FUNCALL_ARGC_MAX)
   if (args != NULL) {
     mrb_free(mrb, args);
   }
+#endif
 
   return result;
 }