From ef7d01971bb0fc9f118e7a0acdb152660e5240c9 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Wed, 19 Mar 2014 17:40:31 +0900
Subject: [PATCH] publish UNREACHABLE macro

---
 include/picrin.h | 7 +++++++
 src/var.c        | 6 ++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/picrin.h b/include/picrin.h
index 6fbfec57..62c05775 100644
--- a/include/picrin.h
+++ b/include/picrin.h
@@ -56,6 +56,13 @@ extern "C" {
 # define GENSYM(x) GENSYM1__(x,__LINE__)
 #endif
 
+#if __GNUC__ || __clang__
+# define UNREACHABLE() (__builtin_unreachable())
+#else
+# include <assert.h>
+# define UNREACHABLE() (assert(false))
+#endif
+
 #include "config.h"
 #include "picrin/value.h"
 
diff --git a/src/var.c b/src/var.c
index 184e4666..b0d1f9f6 100644
--- a/src/var.c
+++ b/src/var.c
@@ -6,8 +6,6 @@
 #include "picrin/proc.h"
 #include "picrin/var.h"
 
-#define UNREACHABLE (assert(false))
-
 struct pic_var *
 pic_var_new(pic_state *pic, pic_value init, struct pic_proc *conv /* = NULL */)
 {
@@ -67,7 +65,7 @@ get_var_from_proc(pic_state *pic, struct pic_proc *proc)
 
  typeerror:
   pic_error(pic, "expected parameter");
-  UNREACHABLE;
+  UNREACHABLE();
 }
 
 static pic_value
@@ -94,7 +92,7 @@ var_call(pic_state *pic)
   else {
     pic_abort(pic, "logic flaw");
   }
-  UNREACHABLE;
+  UNREACHABLE();
 }
 
 struct pic_proc *