Added EVENT__ENABLE_GCC_WARNINGS, turns all warnings into errors.

CMakeLists.txt

@@ -75,6 +75,7 @@ if (EVENT__COVERAGE)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -O0 -fprofile-arcs -ftest-coverage")
 endif()
 
+# GCC specific options.
 if (CMAKE_COMPILER_IS_GNUCC)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 
@@ -94,6 +95,11 @@ if (CMAKE_COMPILER_IS_GNUCC)
         # TODO: Add --gc-sections support. We need some checks for NetBSD to ensure this works.
     endif()
 
+    option(EVENT__ENABLE_GCC_WARNINGS "Make all GCC warnings into errors" OFF)
+    if (EVENT__ENABLE_GCC_WARNINGS)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
+    endif()
+
     # We need to test for at least gcc 2.95 here, because older versions don't
     # have -fno-strict-aliasing
     execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion