We publish libvirt-api.xml for others to use, and in fact, the
libvirt-python bindings use it to generate python constants that
correspond to our enum values.  However, we had an off-by-one bug
that any enum that relied on C's rules for implicit initialization
of the first enum member to 0 got listed in the xml as having a
value of 1 (and all later members of the enum were equally
botched).

The fix is simple - since we add one to the previous value when
encountering an enum without an initializer, the previous value
must start at -1 so that the first enum member is assigned 0.

The python generator code has had the off-by-one ever since DV
first wrote it years ago, but most of our public enums were immune
because they had an explicit = 0 initializer.  The only affected
enums are:
- virDomainEventGraphicsAddressType (such as
VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV4), since commit 987e31ed
(libvirt v0.8.0)
- virDomainCoreDumpFormat (such as VIR_DOMAIN_CORE_DUMP_FORMAT_RAW),
since commit 9fbaff00 (libvirt v1.2.3)
- virIPAddrType (such as VIR_IP_ADDR_TYPE_IPV4), since commit
03e0e79e (not yet released)

Thanks to Nehal J Wani for reporting the problem on IRC, and
for helping me zero in on the culprit function.

* docs/apibuild.py (CParser.parseEnumBlock): Fix implicit enum
values.
Signed-off-by: NEric Blake <eblake@redhat.com>
(cherry picked from commit 9b291bbe)

Consistently use "is" or "is not" to compare variables to None,
because doing so is preferrable, as per PEP 8
(http://www.python.org/dev/peps/pep-0008/#programming-recommendations):

> Comparisons to singletons like None should always be done with is or
> is not, never the equality operators.

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

This patch implements extensible variants of all internal migration APIs
used for v3 migration.

All APIs that take typed parameters are only using params address in
their entry point debug messages. With the new VIR_TYPED_PARAMS_DEBUG
macro, all functions can easily log all individual typed parameters
passed to them.

This API is useful for checking whether only a specific subset of
supported typed parameters were passed.

Ensure that the driver struct field names match the public
API names. For an API virXXXX we must have a driver struct
field xXXXX. ie strip the leading 'vir' and lowercase any
leading uppercase letters.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit 6094ad7b (0.9.3 release) promoted several functions from
internal to public, but forgot to fix the documentation generator
to provide details about those functions.

For an example of what this fixes, look at:
file:///path/to/libvirt/docs/html/libvirt-libvirt.html#virEventAddHandle
before and after the patch.

* docs/apibuild.py (ignored_functions): Don't ignore functions
that were turned into official API.
* src/util/virevent.c: Fix comments to pass through parser.

When a function has no associated information to one of its
arguments or its return type we report it and stop with an error.

When an exception happened inside the try clause in serialize_function,
a new exception was raised in the except clause subsequently:

Traceback (most recent call last):
  File "./apibuild.py", line 2529, in <module>
    rebuild("libvirt")
  File "./apibuild.py", line 2513, in rebuild
    builder.serialize()
  File "./apibuild.py", line 2467, in serialize
    self.serialize_function(output, function)
  File "./apibuild.py", line 2208, in serialize_function
    self.warning("Failed to save function %s info: " % name, `id.info`)
TypeError: warning() takes exactly 2 arguments (3 given)

Use the correct number of arguments for self.warning and print the
original exception to stderr.

Commit f24404a3 renamed virterror.c to
virerror.c but forgot to change the reference in this file.

This patch introduces support for LXC specific public APIs. In
common with what was done for QEMU, this creates a libvirt_lxc.so
library and libvirt/libvirt-lxc.h header file.

The actual APIs are

  int virDomainLxcOpenNamespace(virDomainPtr domain,
                                int **fdlist,
                                unsigned int flags);

  int virDomainLxcEnterNamespace(virDomainPtr domain,
                                 unsigned int nfdlist,
                                 int *fdlist,
                                 unsigned int *noldfdlist,
                                 int **oldfdlist,
                                 unsigned int flags);

which provide a way to use the setns() system call to move the
calling process into the container's namespace. It is not
practical to write in a generically applicable manner. The
nearest that we could get to such an API would be an API which
allows to pass a command + argv to be executed inside a
container. Even if we had such a generic API, this LXC specific
API is still useful, because it allows the caller to maintain
the current process context, in particular any I/O streams they
have open.

NB the virDomainLxcEnterNamespace() API is special in that it
runs client side, so does not involve the internal driver API.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When parsing the top level comment of a file, apibuild.py used
to split on any ':' character of a line regarding the first part
as a key for a setting, e.g. "Summary". The second part would then
be assigned as the value for that key.

This means you could not use a ':' character inside those comments
without ill effects.

Now, a key must consist solely of alphanumeric characters, '_' or '.'.

A block commit moves data in the opposite direction of block pull.
Block pull reduces the chain length by dropping backing files after
data has been pulled into the top overlay, and is always safe; block
commit reduces the chain length by dropping overlays after data has
been committed into the backing file, and any files that depended
on base but not on top are invalidated at any point where they have
unallocated data that is now pointing to changed contents in base.
Both directions are useful, however: a qcow2 layer that is more than
50% allocated will typically be faster with a pull operation, while
a qcow2 layer with less than 50% allocation will be faster as a
commit operation.  Committing across multiple layers can be more
efficient than repeatedly committing one layer at a time, but
requires extra support from the hypervisor.

This API matches Jeff Cody's proposed qemu command 'block-commit':
https://lists.gnu.org/archive/html/qemu-devel/2012-09/msg02226.html

Jeff's command is still in the works for qemu 1.3, and may gain
further enhancements, such as the ability to control on-error
handling (it will be comparable to the error handling Paolo is
adding to 'drive-mirror', so a similar solution will be needed
when I finally propose virDomainBlockCopy with more functionality
than the basics supported by virDomainBlockRebase).  However, even
without qemu support, this API will be useful for _offline_ block
commits, by wrapping qemu-img calls and turning them into a block
job, so this API is worth committing now.

For some examples of how this will be implemented, all starting
with the chain: base <- snap1 <- snap2 <- active

+ These are equivalent:
 virDomainBlockCommit(dom, disk, NULL, NULL, 0, 0)
 virDomainBlockCommit(dom, disk, NULL, "active", 0, 0)
 virDomainBlockCommit(dom, disk, "base", NULL, 0, 0)
 virDomainBlockCommit(dom, disk, "base", "active", 0, 0)
but cannot be implemented for online qemu with round 1 of
Jeff's patches; and for offline images, it would require
three back-to-back qemu-img invocations unless qemu-img
is patched to allow more efficient multi-layer commits;
the end result would be 'base' as the active disk with
contents from all three other files, where 'snap1' and
'snap2' are invalid right away, and 'active' is invalid
once any further changes to 'base' are made.

+ These are equivalent:
 virDomainBlockCommit(dom, disk, "snap2", NULL, 0, 0)
 virDomainBlockCommit(dom, disk, NULL, NULL, 0, _SHALLOW)
they cannot be implemented for online qemu, but for offline,
it is a matter of 'qemu-img commit active', so that 'snap2'
is now the active disk with contents formerly in 'active'.

+ Similarly:
 virDomainBlockCommit(dom, disk, "snap2", NULL, 0, _DELETE)
for an offline domain will merge 'active' into 'snap2', then
delete 'active' to avoid leaving a potentially invalid file
around.

+ This version:
 virDomainBlockCommit(dom, disk, NULL, "snap2", 0, _SHALLOW)
can be implemented online with 'block-commit' passing a base of
snap1 and a top of snap2; and can be implemented offline by
'qemu-img commit snap2' followed by 'qemu-img rebase -u
-b snap1 active'

* include/libvirt/libvirt.h.in (virDomainBlockCommit): New API.
* src/libvirt.c (virDomainBlockCommit): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.10.2): Export it.
* src/driver.h (virDrvDomainBlockCommit): New driver callback.
* docs/apibuild.py (CParser.parseSignature): Add exception.

The method was not existing and did not allow to diagnose problems.

The apibuild.py parser needs to be able to parse & ignore
any VIR_ENUM_IMPL/VIR_ENUM_DECL macros in the source. Add
some special case code to deal with this rather than trying
to figure out a generic syntax for parsing macros.

* apibuild.py: Special case  VIR_ENUM_IMPL & VIR_ENUM_DECL

Qemu is adding the ability to do a partial rebase.  That is, given:

base <- intermediate <- current

virDomainBlockPull will produce:

current

but qemu now has the ability to leave base in the chain, to produce:

base <- current

Note that current qemu can only do a forward merge, and only with
the current image as the destination, which is fully described by
this API without flags.  But in the future, it may be possible to
enhance this API for additional scenarios by using flags:

Merging the current image back into a previous image (that is,
undoing a live snapshot), could be done by passing base as the
destination and flags with a bit requesting a backward merge.

Merging any other part of the image chain, whether forwards (the
backing image contents are pulled into the newer file) or backwards
(the deltas recorded in the newer file are merged back into the
backing file), could also be done by passing a new flag that says
that base should be treated as an XML snippet rather than an
absolute path name, where the XML could then supply the additional
instructions of which part of the image chain is being merged into
any other part.

* include/libvirt/libvirt.h.in (virDomainBlockRebase): New
declaration.
* src/libvirt.c (virDomainBlockRebase): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.9.10): Export it.
* src/driver.h (virDrvDomainBlockRebase): New driver callback.
* src/rpc/gendispatch.pl (long_legacy): Add exemption.
* docs/apibuild.py (long_legacy_functions): Likewise.

The generated docs are: libvirt-qemu-api.xml, libvirt-qemu-refs.xml

Includes impl of python binding since the generator was not
able to cope.

Note: Requires gendispatch.pl patch from Matthias Bolte

https://www.redhat.com/archives/libvir-list/2011-August/msg01367.html

Set up the types for the block pull functions and insert them into the
virDriver structure definition.  Symbols are exported in this patch to
prevent
documentation compile failures.

* include/libvirt/libvirt.h.in: new API
* src/driver.h: add the new entry to the driver structure
* python/generator.py: fix compiler errors, the actual python bindings
* are
  implemented later
* src/libvirt_public.syms: export symbols
* docs/apibuild.py: Extend 'unsigned long' parameter exception to this
* API

The current API build scripts will continue and exit with a zero
status even if they find problems. This has been the cause of many
build problems, or hidden build errors, in the past. Change the
scripts so they always exit with a non-zero status for any problems
they do not understand. Also turn off all debug output by default
so they respect $(AM_V_GEN)

* docs/Makefile.am: Use $(AM_V_GEN) for API/HTML scripts
* docs/apibuild.py, python/generator.py: Exit with non-zero status
  if problems are found. Also be silent, not outputting any debug
  messages.
* src/Makefile.am: Use $(AM_V_GEN) for ESX generator
* python/Makefile.am: Tweak rule

This fixes a number of issues most of them raised by Eric Blake on the
generated documentation output:
   - parsing of "long long int" and similar
   - add parsing of unions within a struct
   - remove spurious " * " fron comments on structure fields and enums
   - fix concatenation of base type and name in arrays
   - extend XSLT to cope with union in structs

* docs/apibuild.py: fix and extend API extraction tool
* docs/newapi.xsl: extend the stylesheets to cope with union in
  public structures

New APIs have to use long long instead of long.

Also make apibuild errors fatal.

This fixes this three warnings from the parser by allowing the parser
to ignore some macros in the same way as it can ignore functions.

Parsing ./../include/libvirt/libvirt.h
Misformatted macro comment for _virSchedParameter
 Expecting '* _virSchedParameter:' got '* virSchedParameter:'
Misformatted macro comment for _virBlkioParameter
 Expecting '* _virBlkioParameter:' got '* virBlkioParameter:'
Misformatted macro comment for _virMemoryParameter
 Expecting '* _virMemoryParameter:' got '* virMemoryParameter:'

Migration just seems to go from bad to worse. We already had to
introduce a second migration protocol when adding the QEMU driver,
since the one from Xen was insufficiently flexible to cope with
passing the data the QEMU driver required.

It turns out that this protocol still has some flaws that we
need to address. The current sequence is

 *  Src: DumpXML
          - Generate XML to pass to dst

 *  Dst: Prepare
          - Get ready to accept incoming VM
          - Generate optional cookie to pass to src

 *  Src: Perform
          - Start migration and wait for send completion
          - Kill off VM if successful, resume if failed

 *  Dst: Finish
          - Wait for recv completion and check status
          - Kill off VM if unsuccessful

The problems with this are:

 - Since the first step is a generic 'DumpXML' call, we can't
   add in other migration specific data. eg, we can't include
   any VM lease data from lock manager plugins
 - Since the first step is a generic 'DumpXML' call, we can't
   emit any 'migration begin' event on the source, or have
   any hook that runs right at the start of the process
 - Since there is no final step on the source, if the Finish
   method fails to receive all migration data & has to kill
   the VM, then there's no way to resume the original VM
   on the source

This patch attempts to introduce a version 3 that uses the
improved 5 step sequence

 *  Src: Begin
          - Generate XML to pass to dst
          - Generate optional cookie to pass to dst

 *  Dst: Prepare
          - Get ready to accept incoming VM
          - Generate optional cookie to pass to src

 *  Src: Perform
          - Start migration and wait for send completion
          - Generate optional cookie to pass to dst

 *  Dst: Finish
          - Wait for recv completion and check status
          - Kill off VM if failed, resume if success
          - Generate optional cookie to pass to src

 *  Src: Confirm
          - Kill off VM if success, resume if failed

The API is designed to allow both input and output cookies
in all methods where applicable. This lets us pass around
arbitrary extra driver specific data between src & dst during
migration. Combined with the extra 'Begin' method this lets
us pass lease information from source to dst at the start of
migration

Moving the killing of the source VM out of Perform and
into Confirm, means we can now recover if the dst host
can't successfully Finish receiving migration data.

Also cfg.mk is tweaked to force this for all future changes to *.py
files.

Even VPATH make dist succeeds now

* include/libvirt/libvirt.h.in: some of the function type description
  were broken so they could not be automatically documented
* src/util/event.c docs/apibuild.py: event.c exports one public API
  so it needs to be scanned too, avoid a few warnings

Use the __declspec(dllexport/dllimport) stuff to export the symbol,
otherwise accessing virConnectAuthPtrDefault triggers a segfault.

* docs/Makefile.am (libvirt-api.xml libvirt-refs.xml): Generalize
apibuild.py to work in a non-srcdir build.  Pass "srcdir" to it.
* docs/apibuild.py (rebuild): Honor the $srcdir envvar.

* src/internal.h (ATTRIBUTE_SENTINEL): New, it's a ggc feature and
  protected as such
* src/util/buf.c (virBufferStrcat): Use it.
* src/util/ebtables.c (ebtablesAddRemoveRule): Use it.
* src/util/iptables.c (iptableAddRemoveRule: Use it.
* src/util/qparams.h (new_qparam_set, append_qparams): Use it.
* docs/apibuild.py: avoid breaking the API generator with that new
  internal keyword macro

* docs/apibuild.py: Make uniq() function sort keys before returning
  them to ensure consitent ordering of <exports> in XML file