From f14d7e06bba5886a0e41a801fa27a8faecde3e43 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Sun, 17 Feb 2019 07:13:14 -0700
Subject: [PATCH] Make noreturn attribute valid only for GNUC implementations

.. with an `exit` call to make the declaration clearly true to the
compiler.
---
 racket/src/racket/include/scheme.h | 9 +++++++++
 racket/src/racket/src/error.c      | 2 ++
 racket/src/racket/src/schemef.h    | 2 +-
 racket/src/racket/src/schemex.h    | 2 +-
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/racket/src/racket/include/scheme.h b/racket/src/racket/include/scheme.h
index 90026477d1..9cebae3bc9 100644
--- a/racket/src/racket/include/scheme.h
+++ b/racket/src/racket/include/scheme.h
@@ -252,6 +252,15 @@ extern "C"
 {
 #endif
 
+/* The reason we need two preprocessor variables is that, in gcc/clang the 
+   function attribute comes after the function declaration. However,
+   in MSVC the function attribute comes before the function declaration. */
+#ifdef __GNUC__
+#define NORETURN __attribute__((__noreturn__))
+#else
+#define NORETURN
+#endif
+
 /* Allowed by all configurations, currently: */
 #define MZ_CAN_ACCESS_THREAD_LOCAL_DIRECTLY
 
diff --git a/racket/src/racket/src/error.c b/racket/src/racket/src/error.c
index aa4c46f9b9..5c9a99c3ae 100644
--- a/racket/src/racket/src/error.c
+++ b/racket/src/racket/src/error.c
@@ -4412,6 +4412,8 @@ scheme_raise_exn(int id, ...)
 #else
   call_error(buffer, alen, scheme_false);
 #endif
+
+  exit(0); /* should not get here, but makes NORETURN clearly true */
 }
 
 #ifndef NO_SCHEME_EXNS
diff --git a/racket/src/racket/src/schemef.h b/racket/src/racket/src/schemef.h
index 28d81790f3..7b827a2bdf 100644
--- a/racket/src/racket/src/schemef.h
+++ b/racket/src/racket/src/schemef.h
@@ -198,7 +198,7 @@ MZ_EXTERN Scheme_On_Atomic_Timeout_Proc scheme_set_on_atomic_timeout(Scheme_On_A
 /*========================================================================*/
 
 MZ_EXTERN void scheme_signal_error(const char *msg, ...);
-MZ_EXTERN void scheme_raise_exn(int exnid, ...) __attribute__ ((noreturn));
+MZ_EXTERN void scheme_raise_exn(int exnid, ...) NORETURN;
 MZ_EXTERN void scheme_warning(char *msg, ...);
 
 MZ_EXTERN void scheme_raise(Scheme_Object *exn);
diff --git a/racket/src/racket/src/schemex.h b/racket/src/racket/src/schemex.h
index bd5a7a408c..e573bd99d8 100644
--- a/racket/src/racket/src/schemex.h
+++ b/racket/src/racket/src/schemex.h
@@ -139,7 +139,7 @@ Scheme_On_Atomic_Timeout_Proc (*scheme_set_on_atomic_timeout)(Scheme_On_Atomic_T
 /*                              error handling                            */
 /*========================================================================*/
 void (*scheme_signal_error)(const char *msg, ...);
-void (*scheme_raise_exn)(int exnid, ...) __attribute__ ((noreturn));
+void (*scheme_raise_exn)(int exnid, ...) NORETURN;
 void (*scheme_warning)(char *msg, ...);
 void (*scheme_raise)(Scheme_Object *exn);
 int (*scheme_log_level_p)(Scheme_Logger *logger, int level);