Support CFLAGS_EXTRA to pass extra user-defined compiler flags (CMake)

* CMakeLists.txt [CFLAGS_EXTRA] (CMAKE_C_FLAGS): Append $(CFLAGS_EXTRA).
* CMakeLists.txt [CFLAGS_EXTRA && enable_cplusplus] (CMAKE_CXX_FLAGS):
Likewise.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1161168dfe81086067ef33b8567f2b8508c445f8..758fac790c4c3a1cd39ec9ba2c7e86ff76159bf7 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -308,6 +308,14 @@ else()
   endif(WIN32)
 endif()
 
+# Extra user-defined flags to pass both to C and C++ compilers.
+if (DEFINED CFLAGS_EXTRA)
+  set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS} ${CFLAGS_EXTRA})
+  if (enable_cplusplus)
+    set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} ${CFLAGS_EXTRA})
+  endif()
+endif()
+
 add_library(gc ${SRC})
 
 if (enable_cplusplus)