cmake: only use -faligned-new and -Wno-noexcept-type if supported

Summary:
On unix platforms, check to see if the compiler supports the `-faligned-new`
and `-Wno-noexcept-type` flags before adding them to the compiler command line
flags.

Reviewed By: yfeldblum

Differential Revision: D6787808

fbshipit-source-id: d34af5ae4251ad3639fdaa1a8d5cb2df4b10e986

CMake/FollyCompilerUnix.cmake

@@ -10,7 +10,6 @@ function(apply_folly_compile_options_to_target THETARGET)
       -fopenmp
       -finput-charset=UTF-8
       -fsigned-char
-      -faligned-new
       -Werror
       -Wall
       -Wno-deprecated
@@ -21,7 +20,7 @@ function(apply_folly_compile_options_to_target THETARGET)
       -Wunused-label
       -Wunused-result
       -Wnon-virtual-dtor
-      -Wno-noexcept-type
+      ${FOLLY_CXX_FLAGS}
     PRIVATE
       -D_REENTRANT
       -D_GNU_SOURCE

CMake/FollyConfigChecks.cmake

@@ -30,6 +30,16 @@ if(NOT CMAKE_SYSTEM_NAME STREQUAL "Windows")
   if (COMPILER_HAS_W_SHADOW_LOCAL AND COMPILER_HAS_W_SHADOW_COMPATIBLE_LOCAL)
     set(FOLLY_HAVE_SHADOW_LOCAL_WARNINGS ON)
   endif()
+
+  CHECK_CXX_COMPILER_FLAG(-Wno-noexcept-type COMPILER_HAS_W_NOEXCEPT_TYPE)
+  if (COMPILER_HAS_W_NOEXCEPT_TYPE)
+    list(APPEND FOLLY_CXX_FLAGS -Wno-noexcept-type)
+  endif()
+
+  CHECK_CXX_COMPILER_FLAG(-faligned-new COMPILER_HAS_F_ALIGNED_NEW)
+  if (COMPILER_HAS_F_ALIGNED_NEW)
+    list(APPEND FOLLY_CXX_FLAGS -faligned-new)
+  endif()
 endif()
 
 check_symbol_exists(pthread_atfork pthread.h FOLLY_HAVE_PTHREAD_ATFORK)