commit 60931e2d8afff685f5460cf9a88469b96942849b
author Vincent Batts <vbatts@redhat.com> Wed Sep 20 11:51:54 2017 -0400
committer David Benjamin <davidben@google.com> Wed Sep 20 19:58:25 2017 +0000
tree 7130390dfbe1e324eba7aa51e0b2d4c459f25dc5
parent 6b35262272e435aa5a6366b3d846fc9125984261

Explicit fallthrough on switch

Fixes failed compile with [-Werror=implicit-fallthrough=], which is
default on gcc-7.x on distributions like fedora.

Enabling no implicit fallthrough for more than just clang as well to
catch this going forward.

Change-Id: I6cd880dac70ec126bd7812e2d9e5ff804d32cadd
Signed-off-by: Vincent Batts <vbatts@redhat.com>
Reviewed-on: https://boringssl-review.googlesource.com/20564
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c32b707..0b95a81 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,6 +38,7 @@
 
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set(C_CXX_FLAGS "-Wall -Werror -Wformat=2 -Wsign-compare -Wmissing-field-initializers -Wwrite-strings -ggdb -fvisibility=hidden -fno-common")
+
   if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     set(C_CXX_FLAGS "${C_CXX_FLAGS} -Wnewline-eof -fcolor-diagnostics")
   else()
@@ -45,6 +46,12 @@
     # and declare that the code is trying to free a stack pointer.
     set(C_CXX_FLAGS "${C_CXX_FLAGS} -Wno-free-nonheap-object")
   endif()
+
+  if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
+     NOT "7.0.0" VERSION_GREATER CMAKE_C_COMPILER_VERSION)
+    set(C_CXX_FLAGS "${C_CXX_FLAGS} -Wimplicit-fallthrough")
+  endif()
+
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${C_CXX_FLAGS} -Wmissing-prototypes -Wold-style-definition -Wstrict-prototypes")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 ${C_CXX_FLAGS} -Wmissing-declarations")
 
@@ -60,7 +67,7 @@
   # https://clang.llvm.org/docs/DiagnosticsReference.html#wmissing-prototypes
   # https://clang.llvm.org/docs/DiagnosticsReference.html#wmissing-declarations
   if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wmissing-prototypes -Wimplicit-fallthrough")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wmissing-prototypes")
   endif()
 elseif(MSVC)
   set(MSVC_DISABLED_WARNINGS_LIST