cmake: check -momit-leaf-frame-pointer before using it

Summary:
because not all archs support this option. see
https://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html.

also do not pass "-fno-omit-frame-pointer" and
"-momit-leaf-frame-pointer" to compiler if ${CMAKE_BUILD_TYPE} is
"Debug". this matches the behaviour of DEBUG_LEVEL=2 in Makefile.
Signed-off-by: NKefu Chai <tchaikov@gmail.com>
Closes https://github.com/facebook/rocksdb/pull/1762

Differential Revision: D4444036

Pulled By: yiwu-arbug

fbshipit-source-id: 8596fbe

CMakeLists.txt

@@ -96,7 +96,14 @@ else()
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -W -Wextra -Wall")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer -momit-leaf-frame-pointer")
+  if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer")
+    include(CheckCXXCompilerFlag)
+    CHECK_CXX_COMPILER_FLAG("-momit-leaf-frame-pointer" HAVE_OMIT_LEAF_FRAME_POINTER)
+    if(HAVE_OMIT_LEAF_FRAME_POINTER)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -momit-leaf-frame-pointer")
+    endif()
+  endif()
 endif()
 
 option(FAIL_ON_WARNINGS "Treat compile warnings as errors" ON)