Reorganize C++ exceptions; ref #3470

There are 3 levels of C++ exception handling:
* default - no C++ exception (use setjmp/longjmp)
* enable_cxx_exception (use C++ exceptions with C ABI)
* enable_cxx_abi (use C++ ABI including exceptions)

2 files changed, 6 insertions, 2 deletions

diff --git a/src/mruby_core.rake b/src/mruby_core.rake
index abde441d5..4558493d9 100644
--- a/src/mruby_core.rake
+++ b/src/mruby_core.rake
@@ -4,11 +4,11 @@ MRuby.each_target do
   current_build_dir = "#{build_dir}/#{relative_from_root}"
 
   objs = Dir.glob("#{current_dir}/*.c").map { |f|
-    next nil if cxx_abi_enabled? and f =~ /(error|vm).c$/
+    next nil if cxx_exception_enabled? and f =~ /(error|vm).c$/
     objfile(f.pathmap("#{current_build_dir}/%n"))
   }.compact
 
-  if cxx_abi_enabled?
+  if cxx_exception_enabled?
     objs += %w(vm error).map { |v| compile_as_cxx "#{current_dir}/#{v}.c", "#{current_build_dir}/#{v}.cxx" }
   end
   self.libmruby << objs
diff --git a/src/vm.c b/src/vm.c
index 458968524..c05afca9d 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -2583,3 +2583,7 @@ mrb_top_run(mrb_state *mrb, struct RProc *proc, mrb_value self, unsigned int sta
 
   return v;
 }
+
+#if defined(MRB_ENABLE_CXX_EXCEPTION) && defined(__cplusplus)
+mrb_int mrb_jmpbuf::jmpbuf_id = 0;
+#endif