build-sys: add -Wimplicit-function-declaration to compiler warnings

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/configure.ac b/configure.ac
index aae2456d59ede6dffd5e3db895c958d9f50075f0..02fc411f7d7ee3c0e8356bff71332ccee812c88f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -116,6 +116,7 @@ UL_WARN_ADD([-Wnested-externs])
 UL_WARN_ADD([-Wpointer-arith])
 UL_WARN_ADD([-Wstrict-prototypes])
 UL_WARN_ADD([-Wformat-security])
+UL_WARN_ADD([-Wimplicit-function-declaration])
 AC_SUBST([WARN_CFLAGS])
 
 UL_WARN_ADD([-Wno-clobbered], [BSD_WARN_CFLAGS])