build: add -Wexpansion-to-defined
This warning is included in -Wall by clang, but not by GCC (which only
enables it for -Wextra). Include it in the list of warnings we enable
to minimize the differences between the compilers:
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/configure b/configure
index 902653a..dceeb72 100755
--- a/configure
+++ b/configure
@@ -1583,7 +1583,7 @@
gcc_flags="-Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers $gcc_flags"
gcc_flags="-Wno-missing-include-dirs -Wempty-body -Wnested-externs $gcc_flags"
gcc_flags="-Wendif-labels -Wno-shift-negative-value $gcc_flags"
-gcc_flags="-Wno-initializer-overrides $gcc_flags"
+gcc_flags="-Wno-initializer-overrides -Wexpansion-to-defined $gcc_flags"
gcc_flags="-Wno-string-plus-int $gcc_flags"
# Note that we do not add -Werror to gcc_flags here, because that would
# enable it for all configure tests. If a configure test failed due
