cmake: only enable supported compiler warning flags
We currently unconditionally enable the "-Wall" and "-Wextra" flags.
Some platforms rely on compilers which do not support these flags,
though. One of these platforms is Haiku, which does not support
"-Wextra" due to being stuck on GCC version 2.
Fix builds on such platforms by adding these flags only if supported by
the compiler.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4bfd1b4..317ad34 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -464,7 +464,10 @@
# Precompiled headers
ELSE ()
- SET(CMAKE_C_FLAGS "-D_GNU_SOURCE -Wall -Wextra ${CMAKE_C_FLAGS}")
+ SET(CMAKE_C_FLAGS "-D_GNU_SOURCE ${CMAKE_C_FLAGS}")
+
+ ADD_C_FLAG_IF_SUPPORTED(-Wall)
+ ADD_C_FLAG_IF_SUPPORTED(-Wextra)
IF (CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
SET(CMAKE_C_FLAGS "-std=c99 -D_POSIX_C_SOURCE=200112L -D__EXTENSIONS__ -D_POSIX_PTHREAD_SEMANTICS ${CMAKE_C_FLAGS}")
