AX_APPEND_COMPILE_FLAGS([ dnl
-Wall dnl
-Wextra dnl
- -Wstrict-prototypes dnl
-Wmissing-prototypes dnl
-Wmissing-declarations dnl
-Wnull-dereference dnl
)
# The test used in AX_APPEND_COMPILE_FLAGS, generated using AC_LANG_PROGRAM, is
-# written in such a way that it triggers a -Wold-style-definition warning. So
-# this warning always ends up disabled if we put it there, because the test
-# program does not build.
+# written in such a way that it triggers warnings with the following warning
+# flags. So they would always end up disabled if we put them there, because
+# the test program would not build.
#
-# Enable it here unconditionally. It is supported by GCC >= 4.8 and by Clang
-# (it is accepted for compatibility although it has no effect), and there is
-# not reason to not want it.
-
-WARN_CFLAGS="${WARN_CFLAGS} -Wold-style-definition"
+# Enable them here unconditionally. They are supported by GCC >= 4.8 and by
+# Clang >= 4.0.
+WARN_CFLAGS="${WARN_CFLAGS} -Wold-style-definition -Wstrict-prototypes"
# CFLAGS from AX_APPEND_COMPILE_FLAGS.
AM_CFLAGS="${AM_CFLAGS} ${WARN_CFLAGS}"