From: Andreas Schneider <asn@samba.org>
Date: Wed, 26 Jul 2017 14:33:10 +0000 (+0200)
Subject: lib:replace: Add FALL_THROUGH support
X-Git-Tag: talloc-2.1.12~403
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=05dae361b388e71701a7c646f2787315e9bd5dfb;p=thirdparty%2Fsamba.git

lib:replace: Add FALL_THROUGH support

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---

diff --git a/.ycm_extra_conf.py b/.ycm_extra_conf.py
index c96b59e373b..97122a9169e 100644
--- a/.ycm_extra_conf.py
+++ b/.ycm_extra_conf.py
@@ -47,6 +47,7 @@ flags = [
     '-D_XOPEN_SOURCE_EXTENDED=1',
     '-DAD_DC_BUILD_IS_ENABLED=1',
     '-DHAVE_IPV6=1',
+    '-DFALL_THROUGH',
     '-I/usr/local/include',
     '-I.',
     '-Iauth',
diff --git a/lib/replace/replace.h b/lib/replace/replace.h
index 128978c561e..e2a55415e04 100644
--- a/lib/replace/replace.h
+++ b/lib/replace/replace.h
@@ -922,6 +922,15 @@ void rep_setproctitle(const char *fmt, ...) PRINTF_ATTRIBUTE(1, 2);
 #define setproctitle_init rep_setproctitle_init
 void rep_setproctitle_init(int argc, char *argv[], char *envp[]);
 #endif
+
+#ifndef FALL_THROUGH
+# ifdef HAVE_FALLTHROUGH_ATTRIBUTE
+#  define FALL_THROUGH __attribute__ ((fallthrough))
+# else /* HAVE_FALLTHROUGH_ATTRIBUTE */
+#  define FALL_THROUGH ((void)0)
+# endif /* HAVE_FALLTHROUGH_ATTRIBUTE */
+#endif /* FALL_THROUGH */
+
 bool nss_wrapper_enabled(void);
 bool nss_wrapper_hosts_enabled(void);
 bool socket_wrapper_enabled(void);
diff --git a/lib/replace/wscript b/lib/replace/wscript
index a2e2d118477..534062ec717 100644
--- a/lib/replace/wscript
+++ b/lib/replace/wscript
@@ -249,6 +249,42 @@ def configure(conf):
                     headers='stdint.h sys/atomic.h',
                     msg='Checking for atomic_add_32 compiler builtin')
 
+    conf.CHECK_CODE('''
+                    #define FALL_THROUGH __attribute__((fallthrough))
+
+                    enum direction_e {
+                        UP = 0,
+                        DOWN,
+                    };
+
+                    int main(void) {
+                        enum direction_e key = UP;
+                        int i = 10;
+                        int j = 0;
+
+                        switch (key) {
+                        case UP:
+                            i = 5;
+                            FALL_THROUGH;
+                        case DOWN:
+                            j = i * 2;
+                            break;
+                        default:
+                            break;
+                        }
+
+                        if (j < i) {
+                            return 1;
+                        }
+
+                        return 0;
+                    }
+                    ''',
+                    'HAVE_FALLTHROUGH_ATTRIBUTE',
+                    addmain=False,
+                    cflags='-Werror',
+                    msg='Checking for fallthrough attribute')
+
     # these may be builtins, so we need the link=False strategy
     conf.CHECK_FUNCS('strdup memmem printf memset memcpy memmove strcpy strncpy bzero', link=False)