Remove custom code for checking compiler warnings, using
gl_WARN_ADD instead. Don't list all flags ourselves, use
gnulib's gl_MANYWARN_ALL_GCC to get all possible GCC flags,
then turn off the ones we don't want yet.
* acinclude.m4: Rewrite to use gl_WARN_ADD and gl_MANYWARN_ALL_GCC
* bootstrap.conf: Add warnings & manywarnings
* configure.ac: Switch to gl_WARN_ADD
* m4/compiler-flags.m4: Obsoleted by gl_WARN_ADD
Even with -Wuninitialized (which is part of autobuild.sh
--enable-compile-warnings=error), gcc does NOT catch this
use of an uninitialized variable:
{
if (cond)
goto error;
int a = 1;
error:
printf("%d", a);
}
which prints 0 (supposing the stack started life wiped) if
cond was true. Clang will catch it, but we don't use clang
as often. Using gcc -Wjump-misses-init catches it, but also
gives false positives:
{
if (cond)
goto error;
int a = 1;
return a;
error:
return 0;
}
Here, a was never used in the scope of the error block, so
declaring it after goto is technically fine (and clang agrees).
However, given that our HACKING already documents a preference
to C89 decl-before-statement, the false positive warning is
enough of a prod to comply with HACKING.
[Personally, I'd _really_ rather use C99 decl-after-statement
to minimize scope, but until gcc can efficiently and reliably
catch scoping and uninitialized usage bugs, I'll settle with
the compromise of enforcing a coding standard that happens to
reject false positives if it can also detect real bugs.]
* acinclude.m4 (LIBVIRT_COMPILE_WARNINGS): Add -Wjump-misses-init.
* src/util/util.c (__virExec): Adjust offenders.
* src/conf/domain_conf.c (virDomainTimerDefParseXML): Likewise.
* src/remote/remote_driver.c (doRemoteOpen): Likewise.
* src/phyp/phyp_driver.c (phypGetLparNAME, phypGetLparProfile)
(phypGetVIOSFreeSCSIAdapter, phypVolumeGetKey)
(phypGetStoragePoolDevice)
(phypVolumeGetPhysicalVolumeByStoragePool)
(phypVolumeGetPath): Likewise.
* src/vbox/vbox_tmpl.c (vboxNetworkUndefineDestroy)
(vboxNetworkCreate, vboxNetworkDumpXML)
(vboxNetworkDefineCreateXML): Likewise.
* src/xenapi/xenapi_driver.c (getCapsObject)
(xenapiDomainDumpXML): Likewise.
* src/xenapi/xenapi_utils.c (createVMRecordFromXml): Likewise.
* src/security/security_selinux.c (SELinuxGenNewContext):
Likewise.
* src/qemu/qemu_command.c (qemuBuildCommandLine): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeEjectableMedia):
Likewise.
* src/qemu/qemu_process.c (qemuProcessWaitForMonitor): Likewise.
* src/qemu/qemu_monitor_text.c (qemuMonitorTextGetPtyPaths):
Likewise.
* src/qemu/qemu_driver.c (qemudDomainShutdown)
(qemudDomainBlockStats, qemudDomainMemoryPeek): Likewise.
* src/storage/storage_backend_iscsi.c
(virStorageBackendCreateIfaceIQN): Likewise.
* src/node_device/node_device_udev.c (udevProcessPCI): Likewise.
This would have detected the bug in commit 38ad33931 (Aug 09), which
we missed until commit f828ca35 (Jul 10); over 11 months later.
However, on Fedora 13, it also triggers LOTS of warnings from
the libcurl-devel header for two files:
esx/esx_vi.c: In function 'esxVI_CURL_Perform':
esx/esx_vi.c:232: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]
esx/esx_vi.c:232: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]
esx/esx_vi.c:232: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]
...
xenapi/xenapi_driver.c: In function 'call_func':
xenapi/xenapi_driver.c:1872: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]
xenapi/xenapi_driver.c:1872: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]
xenapi/xenapi_driver.c:1872: error: logical '&&' with non-zero constant will always evaluate as true [-Wlogical-op]
...
libcurl allows to disable the type-checking code that triggers those
warnings, along with the reduction in type-safety of calls to some
libcurl functions. I figure this is worth the improved compiler
checking throughout the rest of libvirt.
* acinclude.m4 (--enable-compile-warnings=error): Add -Wlogical-op.
* configure.ac: Add -DCURL_DISABLE_TYPECHECK to LIBCURL_CFLAGS to
avoid compilation warning.
Suggested by Daniel P. Berrange.
Tweaked by Matthias Bolte.
Matthias noted that the line:
virt_aa_helper_LDFLAGS = $(WARN_CFLAGS)
looks inconsistent, so I did an audit.
Currently, the set of compiler warning flags passed to gcc as $CC are
equally permitted as the set of linker flags passed to gcc as $LD, so
there was no problem with that usage. But if we ever get in a
situation where $CC and $LD treat particular flags differently, using
the right variable form will make it easier.
In the process, I spotted a couple of typos that were omitting useful
flags, as well as specifying a -l under the wrong variable.
* acinclude.m4 (LIBVIRT_COMPILE_WARNINGS): Define WARN_LDFLAGS as
an alias for WARN_CFLAGS.
* tools/Makefile.am (virsh_LDFLAGS): Use more canonical spelling.
* proxy/Makefile.am (libvirt_proxy_LDFLAGS): Likewise. Move
library...
(libvirt_proxy_LDADD): ...here.
* src/Makefile.am (virt_aa_helper_LDFLAGS): Use more canonical
spelling of WARN_LDFLAGS.
(libvirt_parthelper_LDFLAGS, libvirt_lxc_LDFLAGS): Likewise. Use
correct spelling of COVERAGE_LDFLAGS.
Reported by Matthias Bolte.
by running this command:
git ls-files -z | xargs -0 perl -pi -0777 -e 's/\n\n+$/\n/'
This is in preparation for a more strict make syntax-check
rule that will detect trailing blank lines.
Avoid risk of format string abuse (also avoids gcc warnings).
* src/util.c (ReportError): Use a literal "%s" format string.
* src/remote_internal.c (server_error): Likewise.
* src/qemu_conf.c (qemudReportError): Likewise.
* acinclude.m4: Add -Wformat -Wformat-security to default
list of warning flags, to warn about errors such as the
above.
* acinclude.m4, configure.in: ./configure option
--disable-stack-protector.
* src/gnutls_1_0_compat.h: Compatibility with GnuTLS 1.0.
* src/bridge.c: If no bridge ioctls, give an error at runtime.
* acinclude.m4: add LIBVIRT_COMPILE_WARNINGS, copied from
GNOME but with a few more flags we'd been using.
* configure.in: use that instead of setting CFLAGS
directly.
* proxy/Makefile.am, python/Makefile.am, qemud/Makefile.am,
src/Makefile.am, tests/Makefile.am: use $(WARN_CFLAGS)
