meson: use -Wextra if available

-Wextra was not added to CFLAGS under meson by default, as it is
done by the autotools build.

C.f. 218f46711115669c26389a5bad79e57aa3c37f66.

diff --git a/meson.build b/meson.build
index ce59d18b83fc17970cc00274d8cbde49c30f9d86..22fc8f5b525cb227b18d4e6f7b97be8821c532bc 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -230,7 +230,8 @@ if cxx.found()
         add_languages('cpp')
 endif
 
-foreach arg : ['-Wundef',
+foreach arg : ['-Wextra',
+               '-Wundef',
                '-Wlogical-op',
                '-Wmissing-include-dirs',
                '-Wold-style-definition',