[PATCH netifd 5/5] netifd: Activate -Wextra compile warnings

[Hauke Mehrtens]

This activates some more compile warnings.
-pedantic is not yet activated, then we see too many errors which I do
not know how to mitigate.

Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 CMakeLists.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b3bf411..b87c300 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,7 +7,11 @@ IF(NOT ${CMAKE_VERSION} LESS 3.0)
   check_c_compiler_flag(-Wimplicit-fallthrough HAS_IMPLICIT_FALLTHROUGH)
 ENDIF()
 
-ADD_DEFINITIONS(-Os -Wall -Werror --std=gnu99 -Wmissing-declarations -Wno-unknown-warning-option -Wno-format-truncation)
+ADD_DEFINITIONS(-Os -Wall -Werror --std=gnu99 -Wmissing-declarations -Wno-unused-parameter -Wno-unused-but-set-parameter)
+IF(CMAKE_C_COMPILER_VERSION VERSION_GREATER 6)
+	add_definitions(-Wextra -Werror=implicit-function-declaration)
+	add_definitions(-Wformat -Werror=format-security -Werror=format-nonliteral)
+ENDIF()
 
 IF(HAS_IMPLICIT_FALLTHROUGH)
   ADD_DEFINITIONS(-Wimplicit-fallthrough)
-- 
2.39.1