Enable all possible C compiler warning flags.

We disable the ones that fire, so we can use -Werror. We can then
investigate each warning individually and see whether to fix it or to
keep silencing it.

1 files changed, 7 insertions, 2 deletions

diff --git a/cmake/ModulePackage.cmake b/cmake/ModulePackage.cmake
index a556aef0..26c6c39a 100644
--- a/cmake/ModulePackage.cmake
+++ b/cmake/ModulePackage.cmake
@@ -31,8 +31,13 @@ function(pkg_use_module mod)
   if(${mod}_FOUND)
     link_directories(${${mod}_LIBRARY_DIRS})
     include_directories(${${mod}_INCLUDE_DIRS})
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${${mod}_CFLAGS_OTHER}")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${mod}_CFLAGS_OTHER}")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${${mod}_CFLAGS_OTHER}" PARENT_SCOPE)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${mod}_CFLAGS_OTHER}" PARENT_SCOPE)
+
+    foreach(dir ${${mod}_INCLUDE_DIRS})
+      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -isystem ${dir}" PARENT_SCOPE)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -isystem ${dir}" PARENT_SCOPE)
+    endforeach()
   endif()
 endfunction()