3 files changed, 148 insertions, 27 deletions
diff --git a/mrbgems/mruby-catch/mrblib/catch.rb b/mrbgems/mruby-catch/mrblib/catch.rb
index 68b165c8d..9a60a67a3 100644
--- a/mrbgems/mruby-catch/mrblib/catch.rb
+++ b/mrbgems/mruby-catch/mrblib/catch.rb
@@ -1,22 +1,8 @@
-class ThrowCatchJump < Exception
-  attr_reader :_tag, :_val
-  def initialize(tag, val)
-    @_tag = tag
-    @_val = val
+class UncaughtThrowError < ArgumentError
+  attr_reader :tag, :value
+  def initialize(tag, value)
+    @tag = tag
+    @value = value
     super("uncaught throw #{tag.inspect}")
   end
 end
-
-module Kernel
-  def catch(tag=Object.new, &block)
-    block.call(tag)
-  rescue ThrowCatchJump => e
-    unless e._tag.equal?(tag)
-      raise e
-    end
-    return e._val
-  end
-  def throw(tag, val=nil)
-    raise ThrowCatchJump.new(tag, val)
-  end
-end
diff --git a/mrbgems/mruby-catch/src/catch.c b/mrbgems/mruby-catch/src/catch.c
new file mode 100644
index 000000000..d910cac7f
--- /dev/null
+++ b/mrbgems/mruby-catch/src/catch.c
@@ -0,0 +1,128 @@
+#include <mruby.h>
+#include <mruby/class.h>
+#include <mruby/variable.h>
+#include <mruby/error.h>
+#include <mruby/proc.h>
+#include <mruby/opcode.h>
+#include <mruby/presym.h>
+
+
+MRB_PRESYM_DEFINE_VAR_AND_INITER(catch_syms_3, 1, MRB_SYM(call))
+static const mrb_code catch_iseq_3[18] = {
+  OP_ENTER,    0x00, 0x00, 0x00,
+  OP_GETUPVAR, 0x02, 0x02, 0x01,
+  OP_GETUPVAR, 0x03, 0x01, 0x01,
+  OP_SEND,     0x02, 0x00, 0x01,
+  OP_RETURN,   0x02,};
+static const mrb_irep catch_irep_3 = {
+  2,5,0,
+  MRB_IREP_STATIC,catch_iseq_3,
+  NULL,catch_syms_3,NULL,
+  NULL,
+  NULL,
+  18,0,1,0,0
+};
+static const mrb_irep *catch_reps_2[1] = {
+  &catch_irep_3,
+};
+static const mrb_code catch_iseq_2[13] = {
+  OP_ENTER,    0x00, 0x00, 0x00,
+  OP_LAMBDA,   0x02, 0x00,
+  OP_SEND,     0x02, 0x00, 0x00,
+  OP_RETURN,   0x02,};
+static const mrb_irep catch_irep_2 = {
+  2,4,0,
+  MRB_IREP_STATIC,catch_iseq_2,
+  NULL,catch_syms_3,catch_reps_2,
+  NULL,
+  NULL,
+  13,0,1,1,0
+};
+static const mrb_irep *catch_reps_1[1] = {
+  &catch_irep_2,
+};
+MRB_PRESYM_DEFINE_VAR_AND_INITER(catch_syms_1, 3, MRB_SYM(Object), MRB_SYM(new), MRB_SYM(call))
+static const mrb_code catch_iseq_1[29] = {
+  OP_ENTER,    0x00, 0x20, 0x01,
+  OP_JMP,      0x00, 0x03,
+  OP_JMP,      0x00, 0x0a,
+  OP_GETCONST, 0x03, 0x00,
+  OP_SEND,     0x03, 0x01, 0x00,
+  OP_MOVE,     0x01, 0x03,
+  OP_LAMBDA,   0x03, 0x00,
+  OP_SEND,     0x03, 0x02, 0x00,
+  OP_RETURN,   0x03,};
+static const mrb_irep catch_irep = {
+  3,5,0,
+  MRB_IREP_STATIC,catch_iseq_1,
+  NULL,catch_syms_1,catch_reps_1,
+  NULL,
+  NULL,
+  29,0,3,1,0
+};
+
+#define ID_PRESERVED_CATCH MRB_SYM(__preserved_catch_proc)
+
+static const mrb_callinfo *
+find_catcher(mrb_state *mrb, mrb_value tag)
+{
+  mrb_value pval = mrb_obj_iv_get(mrb, (struct RObject *)mrb->kernel_module, ID_PRESERVED_CATCH);
+  mrb_assert(mrb_proc_p(pval));
+  const struct RProc *proc = mrb_proc_ptr(pval);
+
+  const mrb_callinfo *ci = mrb->c->ci;
+  size_t n = ci - mrb->c->cibase;
+  ci--;
+  for (; n > 0; n--, ci--) {
+    const mrb_value *arg1 = ci->stack + 1;
+    if (ci->proc == proc && mrb_obj_eq(mrb, *arg1, tag)) {
+      return ci;
+    }
+  }
+
+  return NULL;
+}
+
+static mrb_value
+mrb_f_throw(mrb_state *mrb, mrb_value self)
+{
+  mrb_value tag, obj;
+  if (mrb_get_args(mrb, "o|o", &tag, &obj) == 1) {
+    obj = mrb_nil_value();
+  }
+
+  const mrb_callinfo *ci = find_catcher(mrb, tag);
+  if (ci) {
+    struct RBreak *b = (struct RBreak *)mrb_obj_alloc(mrb, MRB_TT_BREAK, NULL);
+    mrb_break_value_set(b, obj);
+    mrb_break_proc_set(b, ci[2].proc); /* Back to the closure in `catch` method */
+    mrb_exc_raise(mrb, mrb_obj_value(b));
+  }
+  else {
+    mrb_value argv[2] = {tag, obj};
+    mrb_exc_raise(mrb, mrb_obj_new(mrb, mrb_exc_get_id(mrb, MRB_ERROR_SYM(UncaughtThrowError)), 2, argv));
+  }
+  /* not reached */
+  return mrb_nil_value();
+}
+
+void
+mrb_mruby_catch_gem_init(mrb_state *mrb)
+{
+  struct RProc *p;
+  mrb_method_t m;
+
+  MRB_PRESYM_INIT_SYMBOLS(mrb, catch_syms_3);
+  MRB_PRESYM_INIT_SYMBOLS(mrb, catch_syms_1);
+  p = mrb_proc_new(mrb, &catch_irep);
+  MRB_METHOD_FROM_PROC(m, p);
+  mrb_define_method_raw(mrb, mrb->kernel_module, MRB_SYM(catch), m);
+  mrb_obj_iv_set(mrb, (struct RObject *)mrb->kernel_module, ID_PRESERVED_CATCH, mrb_obj_value(p));
+
+  mrb_define_method(mrb, mrb->kernel_module, "throw", mrb_f_throw, MRB_ARGS_ARG(1,1));
+}
+
+void
+mrb_mruby_catch_gem_final(mrb_state *mrb)
+{
+}
diff --git a/mrbgems/mruby-catch/test/catch.rb b/mrbgems/mruby-catch/test/catch.rb
index fe5bda096..38a4eb907 100644
--- a/mrbgems/mruby-catch/test/catch.rb
+++ b/mrbgems/mruby-catch/test/catch.rb
@@ -3,10 +3,14 @@ assert "return throw value" do
   result = catch :foo do
     loop do
       loop do
-        throw :foo, val
+        begin
+          throw :foo, val
+        rescue Exception
+          flunk("should not reach here 1")
+        end
         break
       end
-      flunk("should not reach here")
+      flunk("should not reach here 2")
     end
     false
   end
@@ -30,13 +34,16 @@ assert "pass the given tag to block" do
   catch(tag){|t| assert_same(tag, t)}
 end
 
-assert "tag identity" do
-  assert_raise_with_message_pattern(Exception, "uncaught throw *") do
-    catch [:tag] do
-      throw [:tag]
-    end
-    flunk("should not reach here")
+assert "tag identity, uncaught throw" do
+  tag, val = [:tag], [:val]
+  catch [:tag] do
+    throw tag, val
   end
+  flunk("should not reach here")
+rescue Exception => e
+  assert_match("uncaught throw *", e.message)
+  assert_same(tag, e.tag)
+  assert_same(val, e.value)
 end
 
 assert "without catch arguments" do