From 067fd4934bc7321b7ab1ce1d9fd80d472729f973 Mon Sep 17 00:00:00 2001
From: Jimmy Nguyen <jinguyen@9801a7949465.ant.amazon.com>
Date: Tue, 7 Feb 2017 11:54:10 -0800
Subject: [PATCH] Refactored warning flag checks to use `CheckCXXCompilerFlag`
 module since Windows can compile without MSVC

---
 CMakeLists.txt | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0497b47..ed4c2f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,13 +18,14 @@ target_compile_options(json11
   PRIVATE -fPIC -fno-rtti -fno-exceptions -Wall)
 
 # Set warning flags, which may vary per platform
-if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
-  target_compile_options(json11
-    PRIVATE /W4 /WX)
-else()
-  target_compile_options(json11
-    PRIVATE -Wextra -Werror)
-endif()
+include(CheckCXXCompilerFlag)
+set(_possible_warnings_flags /W4 /WX -Wextra -Werror)
+foreach(_warning_flag in ${_possible_warnings_flags})
+  CHECK_CXX_COMPILER_FLAG(_warning_flag _flag_supported)
+  if(${_flag_supported})
+    target_compile_options(json11 PRIVATE ${_warning_flag})
+  endif()
+endforeach()
 
 configure_file("json11.pc.in" "json11.pc" @ONLY)