Every time we write XML into a file we call virEmitXMLWarning to write a
warning that the file is automatically generated. virXMLSaveFile
simplifies this into a single step and makes rewriting existing XML file
safe by using virFileRewrite internally.

This patch modifies error handling function for the XML parser provided
by libxml2.

Originaly only a line number and error message were logged. With this
new error handler function, the user is provided with a more complex
description of the parsing error.

Context of the error is printed in libXML2 style and filename of the
file, that caused the error is printed. Example of an parse error:

13:41:36.262: 16032: error : catchXMLError:706 :
/etc/libvirt/qemu/rh_bad.xml:58: Opening and ending tag mismatch: name
line 2 and domain
</domain>
---------^

Context of the error gives the user hints that may help to quickly
locate a corrupt xml file.

fixes BZs:
----------
Bug 708735 - [RFE] Show column and line on XML parsing error
https://bugzilla.redhat.com/show_bug.cgi?id=708735

Bug 726771 - libvirt does not specify problem file if persistent xml is
invalid
https://bugzilla.redhat.com/show_bug.cgi?id=726771

Often, we want to use XPath functions on the just-parsed document;
fold this into the parser function for convenience.

* src/util/xml.h (virXMLParseHelper): Add argument.
(virXMLParseStrHelper, virXMLParseFileHelper): Delete.
(virXMLParseCtxt, virXMLParseStringCtxt, virXMLParseFileCtxt): New
macros.
* src/libvirt_private.syms (xml.h): Remove deleted functions.
* src/util/xml.c (virXMLParseHelper): Add argument.
(virXMLParseStrHelper, virXMLParseFileHelper): Delete.

And update callers to actually respect the error

And from all related macros and functions.

Signed-off-by: NEric Blake <eblake@redhat.com>

Detected by clang.

* src/util/xml.c (virXPathStringLimit): Use %zd, not obsolete %Zd.

It was awkward having only int conversion in the virStrToLong family,
but only long conversion in the virXPath family.  Make both families
support both types.

* src/util/util.h (virStrToLong_l, virStrToLong_ul): New
prototypes.
* src/util/xml.h (virXPathInt, virXPathUInt): Likewise.
* src/util/util.c (virStrToLong_l, virStrToLong_ul): New
functions.
* src/util/xml.c (virXPathInt, virXPathUInt): Likewise.
* src/libvirt_private.syms (util.h, xml.h): Export them.

Prior to this patch, there was an inconsistent mix between GNU and C99.

For consistency, and potential portability to other compilers, stick
with the C99 vararg macro syntax.

* src/conf/cpu_conf.c (virCPUReportError): Use C99 rather than GNU
  vararg macro syntax.
* src/conf/domain_conf.c (virDomainReportError): Likewise.
* src/conf/domain_event.c (eventReportError): Likewise.
* src/conf/interface_conf.c (virInterfaceReportError): Likewise.
* src/conf/network_conf.c (virNetworkReportError): Likewise.
* src/conf/node_device_conf.h (virNodeDeviceReportError): Likewise.
* src/conf/secret_conf.h (virSecretReportError): Likewise.
* src/conf/storage_conf.h (virStorageReportError): Likewise.
* src/esx/esx_device_monitor.c (ESX_ERROR): Use C99 rather than
  GNU vararg macro syntax.
* src/esx/esx_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_interface_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_network_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_secret_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_storage_driver.c (ESX_ERROR): Likewise.
* src/esx/esx_util.c (ESX_ERROR): Likewise.
* src/esx/esx_vi.c (ESX_VI_ERROR): Likewise.
* src/esx/esx_vi_methods.c (ESX_VI_ERROR): Likewise.
* src/esx/esx_vi_types.c (ESX_VI_ERROR): Likewise.
* src/esx/esx_vmx.c (ESX_ERROR): Likewise.
* src/util/hostusb.c (usbReportError): Use C99 rather than GNU
  vararg macro syntax.
* src/util/json.c (virJSONError): Likewise.
* src/util/macvtap.c (ReportError): Likewise.
* src/util/pci.c (pciReportError): Likewise.
* src/util/stats_linux.c (virStatsError): Likewise.
* src/util/util.c (virUtilError): Likewise.
* src/util/xml.c (virXMLError): Likewise.
* src/xen/proxy_internal.c (virProxyError): Use C99 rather than
  GNU vararg macro syntax.
* src/xen/sexpr.c (virSexprError): Likewise.
* src/xen/xen_driver.c (xenUnifiedError): Likewise.
* src/xen/xen_hypervisor.c (virXenError): Likewise.
* src/xen/xen_inotify.c (virXenInotifyError): Likewise.
* src/xen/xend_internal.c (virXendError): Likewise.
* src/xen/xm_internal.c (xenXMError): Likewise.
* src/xen/xs_internal.c (virXenStoreError): Likewise.
* src/cpu/cpu.h (virCPUReportError): Use C99 rather than GNU
  vararg macro syntax.
* src/datatypes.c (virLibConnError): Likewise.
* src/interface/netcf_driver.c (interfaceReportError): Likewise.
* src/libvirt.c (virLibStreamError): Likewise.
* src/lxc/lxc_conf.h (lxcError): Likewise.
* src/network/bridge_driver.c (networkReportError): Likewise.
* src/nodeinfo.c (nodeReportError): Likewise.
* src/opennebula/one_conf.h (oneError): Likewise.
* src/openvz/openvz_conf.h (openvzError): Likewise.
* src/phyp/phyp_driver.c (PHYP_ERROR): Likewise.
* src/qemu/qemu_conf.h (qemuReportError): Likewise.
* src/remote/remote_driver.c (errorf): Likewise.
* src/security/security_driver.h (virSecurityReportError): Likewise.
* src/test/test_driver.c (testError): Likewise.
* src/uml/uml_conf.h (umlReportError): Likewise.
* src/vbox/vbox_driver.c (vboxError): Likewise.
* src/vbox/vbox_tmpl.c (vboxError): Likewise.

This introduces a third option for clock offset synchronization,
that allows an arbitrary / variable adjustment to be set. In
essence the XML contains the time delta in seconds, relative to
UTC.

  <clock offset='variable' adjustment='123465'/>

The difference from 'utc' mode, is that management apps should
track adjustments and preserve them at next reboot.

* docs/schemas/domain.rng: Schema for new clock mode
* src/conf/domain_conf.c, src/conf/domain_conf.h: Parse
  new clock time delta
* src/libvirt_private.syms, src/util/xml.c, src/util/xml.h: Add
  virXPathLongLong() method

It was used for error reporting only.

virXPathNodeSet() could return -1 when doing an evaluation failure
due to xmlXPathEval() from libxml2 behaviour.
* src/util/xml.c: make sure we always return 0 unless the returned
  XPath type is of the wrong type (meaning the query passed didn't
  evaluate to a node set and code must be fixed)

* src/util/xml.c: The virXPath... function take extra care to preserve
  the XPath context node (ctxt->node) but in the case of virXPathString
  and virXPathBoolean they forgot to do this on the error path. This
  patch fixes this and move all ctxt->node = relnode instuctions just
  after the xmlXPathEval() to make sure this doesn't happen if this code
  is modified.

* src/bridge.c, src/bridge.h, src/buf.c, src/buf.h, src/cgroup.c,
  src/cgroup.h, src/conf.c, src/conf.h, src/event.c, src/event.h,
  src/hash.c, src/hash.h, src/hostusb.c, src/hostusb.h,
  src/iptables.c, src/iptables.h, src/logging.c, src/logging.h,
  src/memory.c, src/memory.h, src/pci.c, src/pci.h, src/qparams.c,
  src/qparams.h, src/stats_linux.c, src/stats_linux.h,
  src/threads-pthread.c, src/threads-pthread.h, src/threads-win32.c,
  src/threads-win32.h, src/threads.c, src/threads.h, src/util.c,
  src/util.h, src/uuid.c, src/uuid.h, src/virterror.c,
  src/virterror_internal.h, src/xml.c, src/xml.h: Move all files
  into src/util/
* daemon/Makefile.am: Add -Isrc/util/ to build flags
* src/Makefile.am: Add -Isrc/util/ to build flags and update for
  moved files
* src/libvirt_private.syms: Export cgroup APIs since they're now
  in util rather than linking directly to drivers
* src/xen/xs_internal.c: Disable bogus virEventRemoveHandle call
  when built under PROXY
* proxy/Makefile.am: Update for changed file locations. Remove
  bogus build of event.c
* tools/Makefile.am, tests/Makefile.am: Add -Isrc/util/ to build flags

Add a variant of virXPathULong() which can handle long longs.

Needed for parsing storage device capacities.

Add new functions to allow parsing integers with base 16

This will be used to e.g. parse PCI vendor IDs.

Just some copy-and-paste mixups.

* src/uml_conf.c (VIR_FROM_THIS): Define to VIR_FROM_UML.
* src/xs_internal.c (VIR_FROM_THIS): Define to VIR_FROM_XEN.
* src/xml.c (VIR_FROM_THIS): Define to VIR_FROM_XML.
* src/stats_linux.c (VIR_FROM_THIS): Define to VIR_FROM_STATS_LINUX.
* src/datatypes.c (VIR_FROM_THIS): Define to VIR_FROM_NONE.
* src/lxc_conf.c (VIR_FROM_THIS): Define to VIR_FROM_LXC.
* src/libvirt.c (VIR_FROM_THIS): Define to VIR_FROM_NONE.
* src/node_device_conf.c (VIR_FROM_THIS): Define to VIR_FROM_NODEDEV.
* src/openvz_conf.c (VIR_FROM_THIS): Define to VIR_FROM_OPENVZ.
* src/openvz_driver.c (VIR_FROM_THIS): Define to VIR_FROM_OPENVZ.
* src/conf.c (VIR_FROM_THIS): Define to VIR_FROM_CONF.
Note: this loses config_filename:config_lineno diagnostics,
but that's ok.
* src/node_device.c (VIR_FROM_THIS): Define to VIR_FROM_NODEDEV.
* src/sexpr.c (VIR_FROM_THIS): Define to VIR_FROM_SEXPR.
* po/POTFILES.in: remove src/sexpr.c and src/lxc_conf.c

Building with --disable-nls exposed many new warnings like these:
virsh.c:4952: warning: format not a string literal and no format ...
util.c:163: warning: format not a string literal and no format arguments
All but one of the following changes add a "%s" argument before
the offending _(...) argument.

This was the only manual change:
* src/lxc_driver.c (lxcVersion): Use %s and strerror(errno)
rather than %m, to avoid a warning from gcc -Wformat-security.

Add "%s" before each warned about format-string-with-no-%-directive:
* src/domain_conf.c (virDomainHostdevSubsysUsbDefParseXML)
(virDomainDefParseString, virDomainDefParseFile):
* src/hash.c (virGetConnect, __virGetDomain, virReleaseDomain)
(__virGetNetwork, virReleaseNetwork, __virGetStoragePool)
(virReleaseStoragePool, __virGetStorageVol, virReleaseStorageVol):
* src/lxc_container.c (lxcContainerChild):
* src/lxc_driver.c (lxcDomainDefine, lxcDomainUndefine)
(lxcDomainGetInfo, lxcGetOSType, lxcDomainDumpXML)
(lxcSetupInterfaces, lxcDomainStart, lxcDomainCreateAndStart)
(lxcVersion, lxcGetSchedulerParameters):
* src/network_conf.c (virNetworkDefParseString)
(virNetworkDefParseFile):
* src/openvz_conf.c (openvzReadNetworkConf, openvzLoadDomains):
* src/openvz_driver.c (openvzDomainDefineCmd)
(openvzDomainGetInfo, openvzDomainDumpXML, openvzDomainShutdown)
(openvzDomainReboot, ADD_ARG_LIT, openvzDomainDefineXML)
(openvzDomainCreateXML, openvzDomainCreate, openvzDomainUndefine)
(openvzDomainSetAutostart, openvzDomainGetAutostart)
(openvzDomainSetVcpus):
* src/qemu_driver.c (qemudDomainBlockPeek, qemudDomainMemoryPeek):
* src/remote_internal.c (remoteDomainBlockPeek)
(remoteDomainMemoryPeek, remoteAuthPolkit):
* src/sexpr.c (sexpr_new, _string2sexpr):
* src/storage_backend_disk.c (virStorageBackendDiskMakeDataVol)
(virStorageBackendDiskCreateVol):
* src/storage_backend_fs.c
(virStorageBackendFileSystemNetFindPoolSources):
* src/storage_backend_logical.c (virStorageBackendLogicalFindLVs)
(virStorageBackendLogicalFindPoolSources):
* src/test.c (testOpenDefault, testOpenFromFile, testOpen)
(testGetDomainInfo, testDomainRestore)
(testNodeGetCellsFreeMemory):
* src/util.c (virExec):
* src/virsh.c (cmdAttachDevice, cmdDetachDevice)
(cmdAttachInterface, cmdDetachInterface, cmdAttachDisk)
(cmdDetachDisk, cmdEdit):
* src/xend_internal.c (do_connect, wr_sync, xend_op_ext)
(urlencode, xenDaemonDomainCreateXML)
(xenDaemonDomainLookupByName_ids, xenDaemonDomainLookupByID)
(xenDaemonParseSxprOS, xend_parse_sexp_desc_char)
(xenDaemonParseSxprChar, xenDaemonParseSxprDisks)
(xenDaemonParseSxpr, sexpr_to_xend_topology, sexpr_to_domain)
(xenDaemonDomainFetch, xenDaemonDomainGetAutostart)
(xenDaemonDomainSetAutostart, xenDaemonDomainMigratePerform)
(xenDaemonDomainDefineXML, xenDaemonGetSchedulerType)
(xenDaemonGetSchedulerParameters)
(xenDaemonSetSchedulerParameters, xenDaemonDomainBlockPeek)
(xenDaemonFormatSxprChr, virDomainXMLDevID):
* src/xm_internal.c (xenXMConfigCacheRefresh, xenXMDomainPinVcpu)
(xenXMDomainCreate, xenXMDomainDefineXML)
(xenXMDomainAttachDevice, xenXMDomainDetachDevice):
* src/xml.c (virXPathString, virXPathNumber, virXPathLong)
(virXPathULong, virXPathBoolean, virXPathNode, virXPathNodeSet):
* src/xs_internal.c (xenStoreOpen):

	* qemud/internal.h, qemud/qemud.h: Rename this file so it
	doesn't conflict with src/internal.h.
	* HACKING: Document how header files should be used.
	* qemud/Makefile.am: Add src/ directory to includes.
	* qemud/event.c, qemud/mdns.c, qemud/qemud.c, qemud/remote.c,
	qemud/remote_protocol.c, qemud/remote_protocol.h,
	qemud/remote_protocol.x, src/buf.c, src/libvirt.c,
	src/nodeinfo.c, src/qemu_conf.c, src/qemu_driver.c,
	src/stats_linux.c, src/storage_backend.c, src/storage_backend_fs.c,
	src/storage_backend_iscsi.c, src/storage_backend_logical.c,
	src/storage_conf.c, src/storage_driver.c, src/util.c,
	src/util.h, src/virsh.c, src/virterror.c, src/xend_internal.c,
	src/xml.c, tests/reconnect.c, tests/xmlrpctest.c,
	tests/qparamtest.c: Standardize	use of header files.
	* docs/*, po/*: Rebuild docs.

Up to now, we've been avoiding ctype functions like isspace, isdigit,
etc.  because they are locale-dependent.  Now that we have the c-ctype
functions, we can start using *them*, to make the code more readable
with changes like these:

-        /* This may not work on EBCDIC. */
-        if ((*p >= 'a' && *p <= 'z') ||
-            (*p >= 'A' && *p <= 'Z') ||
-            (*p >= '0' && *p <= '9'))
+        if (c_isalnum(*p))

-    while ((*cur >= '0') && (*cur <= '9')) {
+    while (c_isdigit(*cur)) {

Also, some macros in conf.c used names that conflicted with
standard meaning of "BLANK" and "SPACE", so I've adjusted them
to be in line with the definition of e.g., isblank.
In addition, I've wrapped those statement macros with do {...} while (0),
so that we can't forget the ";" after a use.  There was one like that
already (fixed below).  The missing semicolon would mess up automatic
indenting.
* src/buf.c (virBufferURIEncodeString):
* src/conf.c (IS_EOL, SKIP_BLANKS_AND_EOL, SKIP_BLANKS)
(virConfParseLong, virConfParseValue, virConfParseName)
(virConfParseSeparator, virConfParseStatement, IS_BLANK, IS_CHAR)
(IS_DIGIT, IS_SPACE, SKIP_SPACES):
* src/nodeinfo.c:
* src/qemu_conf.c (qemudParseInterfaceXML):
* src/qemu_driver.c (qemudDomainBlockStats):
* src/sexpr.c:
* src/stats_linux.c:
* src/util.c (virParseNumber, virDiskNameToIndex):
* src/uuid.c (hextobin, virUUIDParse):
* src/virsh.c:
* src/xml.c (parseCpuNumber, virParseCpuSet):

* src/qemu_conf.c src/qemu_conf.h src/xend_internal.c
  src/xend_internal.h src/xm_internal.c src/xml.c src/xml.h:
  Patch from Cole Robinson adding sound support for QEmu and Xen
* tests/qemuxml2argvtest.c tests/sexpr2xmltest.c
  tests/xmconfigtest.c tests/xml2sexprtest.c:
  Associated regression tests
Daniel