On 04/08/2016 12:27 PM, Andrea Bolognani wrote:
> On Mon, 2016-02-29 at 15:41 +0100, Martin Kletzander wrote:
>> On Wed, Feb 24, 2016 at 02:29:58PM -0700, Eric Blake wrote:
>>>
>>> gcc 6.0 added an annoying warning:
>>>
>>> fdstream.c: In function 'virFDStreamWrite':
>>> fdstream.c:390:29: error: logical 'or' of equal expressions [-Werror=logical-op]
>>> if (errno == EAGAIN || errno == EWOULDBLOCK) {
>>> ^~
>>> fdstream.c: In function 'virFDStreamRead':
>>> fdstream.c:440:29: error: logical 'or' of equal expressions [-Werror=logical-op]
>>> if (errno == EAGAIN || errno == EWOULDBLOCK) {
>>> ^~
>>>
>>> This makes it impossible to build out-of-the-box on rawhide,
>>> and we aren't guaranteed that the gcc bug will be fixed in a
>>> timely manner:
>>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69602
>>>
>>> So work around it by further complicating the logic to thwart the
>>> compiler.
>>>
>>> Signed-off-by: Eric Blake <eblake@xxxxxxxxxx>
>>> ---
>>>
>>> This is a build-breaker fix for rawhide; but I'll wait for a day
>>> for any reasons why I should not push it during freeze.
>>>
>> It looks like you're still talking this over and thinking about
>> approaches. But could we push the fix for the time being so that the
>> release is nicely buildable and then work on making it nicer later? I'd
>> vote ACK for that.
>
> Update: the libvirt-fedora-rawhide build host on CentOS CI
> has been updated and it's now running gcc 6.0. The immediate
> result is that build jobs have started to fail (see [1] for
> an example).
>
> Looking at the gcc bug, it doesn't look like there's been
> much movement in that area, so I think we should take some
> action on our side...
>
> Eric, you mentioned proposing a v2 that would use #pragma
> instead of uglifying the current checks. Do you still
> intend to work on such alternative approach?
>
I've attached a patch with the pragma push/pop approach Eric mentioned.
Unfortunately it doesn't work as is on RHEL6 vintage gcc so it's probably not
a realistic option.
> Failing that, I'm personally okay with pushing this.
>
I agree
- Cole
>From 5df55b50e143677d0b47b0e67ffd28184e4c0556 Mon Sep 17 00:00:00 2001
Message-Id: <5df55b50e143677d0b47b0e67ffd28184e4c0556.1460254498.git.crobinso@xxxxxxxxxx>
From: Cole Robinson <crobinso@xxxxxxxxxx>
Date: Sat, 9 Apr 2016 21:46:52 -0400
Subject: [PATCH] build: Avoid -Wlogical-op bug on gcc6
Use pragma push/pop to disable -Wlogical-op for the problematic
conditionals.
gcc bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69602
https://www.redhat.com/archives/libvir-list/2016-February/msg00054.html
---
Unfortunately this doesn't work on RHEL6... gcc errors about #pragma
in a function call
src/fdstream.c | 6 ++++++
src/rpc/virnetsshsession.c | 9 +++++++++
src/security/security_selinux.c | 6 +++++-
3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/src/fdstream.c b/src/fdstream.c
index a85cf9d..0422ac5 100644
--- a/src/fdstream.c
+++ b/src/fdstream.c
@@ -387,7 +387,10 @@ static int virFDStreamWrite(virStreamPtr st, const char *bytes, size_t nbytes)
retry:
ret = write(fdst->fd, bytes, nbytes);
if (ret < 0) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wlogical-op"
if (errno == EAGAIN || errno == EWOULDBLOCK) {
+#pragma GCC diagnostic pop
ret = -2;
} else if (errno == EINTR) {
goto retry;
@@ -437,7 +440,10 @@ static int virFDStreamRead(virStreamPtr st, char *bytes, size_t nbytes)
retry:
ret = read(fdst->fd, bytes, nbytes);
if (ret < 0) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wlogical-op"
if (errno == EAGAIN || errno == EWOULDBLOCK) {
+#pragma GCC diagnostic pop
ret = -2;
} else if (errno == EINTR) {
goto retry;
diff --git a/src/rpc/virnetsshsession.c b/src/rpc/virnetsshsession.c
index 406a831..a77571f 100644
--- a/src/rpc/virnetsshsession.c
+++ b/src/rpc/virnetsshsession.c
@@ -545,9 +545,12 @@ virNetSSHAuthenticateAgent(virNetSSHSessionPtr sess,
agent_identity)))
return 0; /* key accepted */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wlogical-op"
if (ret != LIBSSH2_ERROR_AUTHENTICATION_FAILED &&
ret != LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED &&
ret != LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED) {
+#pragma GCC diagnostic pop
libssh2_session_last_error(sess->session, &errmsg, NULL, 0);
virReportError(VIR_ERR_AUTH_FAILED,
_("failed to authenticate using SSH agent: %s"),
@@ -605,9 +608,12 @@ virNetSSHAuthenticatePrivkey(virNetSSHSessionPtr sess,
priv->password)) == 0)
return 0; /* success */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wlogical-op"
if (priv->password ||
ret == LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED ||
ret == LIBSSH2_ERROR_AUTHENTICATION_FAILED) {
+#pragma GCC diagnostic pop
libssh2_session_last_error(sess->session, &errmsg, NULL, 0);
virReportError(VIR_ERR_AUTH_FAILED,
_("authentication with private key '%s' "
@@ -673,11 +679,14 @@ virNetSSHAuthenticatePrivkey(virNetSSHSessionPtr sess,
"has failed: %s"),
priv->filename, errmsg);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wlogical-op"
if (ret == LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED ||
ret == LIBSSH2_ERROR_AUTHENTICATION_FAILED)
return 1;
else
return -1;
+#pragma GCC diagnostic pop
}
return 0;
diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c
index 26d95d1..b702fb3 100644
--- a/src/security/security_selinux.c
+++ b/src/security/security_selinux.c
@@ -911,8 +911,12 @@ virSecuritySELinuxSetFileconHelper(const char *path, char *tcon,
* hopefully sets one of the necessary SELinux virt_use_{nfs,usb,pci}
* boolean tunables to allow it ...
*/
- if (setfilecon_errno != EOPNOTSUPP && setfilecon_errno != ENOTSUP &&
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wlogical-op"
+ if (setfilecon_errno != EOPNOTSUPP &&
+ setfilecon_errno != ENOTSUP &&
setfilecon_errno != EROFS) {
+#pragma GCC diagnostic pop
virReportSystemError(setfilecon_errno,
_("unable to set security context '%s' on '%s'"),
tcon, path);
--
2.7.3
--
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