[commit: ghc] master: refactor test for __builtin_unreachable into Rts.h macro RTS_UNREACHABLE (3551e62)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/3551e622ab3a833589a069b473a4dfb3f171e5b8/ghc

>---------------------------------------------------------------

commit 3551e622ab3a833589a069b473a4dfb3f171e5b8
Author: Karel Gardas <karel.gardas at centrum.cz>
Date:   Mon Aug 15 22:26:04 2016 +0200

    refactor test for __builtin_unreachable into Rts.h macro RTS_UNREACHABLE
    
    Summary:
    This patch refactors GNU C version test (for 4.5 and more modern)
    due to usage of __builtin_unreachable done in the CNF.c code directly
    into the new RTS_UNREACHABLE macro placed into Rts.h
    
    Reviewers: bgamari, austin, simonmar, erikd
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D2457


>---------------------------------------------------------------

3551e622ab3a833589a069b473a4dfb3f171e5b8
 includes/Rts.h | 7 +++++++
 rts/sm/CNF.c   | 5 +----
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/includes/Rts.h b/includes/Rts.h
index 3d4538f..be81b0d 100644
--- a/includes/Rts.h
+++ b/includes/Rts.h
@@ -61,6 +61,13 @@ extern "C" {
 #define RTS_UNLIKELY(p) p
 #endif
 
+/* __builtin_unreachable is supported since GNU C 4.5 */
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+#define RTS_UNREACHABLE __builtin_unreachable()
+#else
+#define RTS_UNREACHABLE abort()
+#endif
+
 /* Fix for mingw stat problem (done here so it's early enough) */
 #ifdef mingw32_HOST_OS
 #define __MSVCRT__ 1
diff --git a/rts/sm/CNF.c b/rts/sm/CNF.c
index 0594a6e..f8e706a 100644
--- a/rts/sm/CNF.c
+++ b/rts/sm/CNF.c
@@ -164,11 +164,8 @@ compactAllocateBlockInternal(Capability            *cap,
     default:
 #ifdef DEBUG
         ASSERT(!"code should not be reached");
-#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
-        /* __builtin_unreachable is supported since GNU C 4.5 */
-        __builtin_unreachable();
 #else
-        abort();
+        RTS_UNREACHABLE;
 #endif
     }
     RELEASE_SM_LOCK;