Re: [libvirt] [PATCH] build: ask for -std=gnu99 explicitly
On Mon, Oct 07, 2019 at 15:09:52 +0100, Daniel Berrange wrote:
We previously got -std=gnu99 secretly enabled as a side-effect
of requesting the 'stdarg' gnulib module. We rely on some
extensions from c99/gnu99 and while RHEL-7 supports this, it
still defaults to gnu89. RHEL-7 also supports some newer
standards but declares them experimental/incomplete, so sticking
with gnu99 is best bet for now & matches historical usage.
Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com>
---
m4/virt-compile-warnings.m4 | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4
index f9460e82ba..502f7384ff 100644
--- a/m4/virt-compile-warnings.m4
+++ b/m4/virt-compile-warnings.m4
@@ -189,6 +189,10 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[
wantwarn="$wantwarn -Werror"
fi
+ # Request the gnu99 standard which is the best choice with
+ # gcc 4.8.0
+ wantwarn="-std=gnu99"
+
It feels odd to add this via the warning flags variable.
I know this is a hack until we get rid of the old build system, but I
think you should at least admit it in the commit message or comment that
it's deliberate.