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

Based on a report by Chandrashekar Shastri, at
https://bugzilla.redhat.com/show_bug.cgi?id=979360

On systems where git cannot access the outside world, a developer
can instead arrange to get a copy of gnulib at the right commit
via side channels (such as NFS share drives), set GNULIB_SRCDIR,
then use ./autogen.sh --no-git.  In this setup, we will now
avoid direct use of git.  Of course, this means no automatic
gnulib updates when libvirt.git updates its submodule, but it
is expected that any developer in such a situation is already
prepared to deal with the fallout.

* .gnulib: Update to latest, for bootstrap.
* bootstrap: Synchronize from gnulib.
* autogen.sh (no_git): Avoid git when requested.
* cfg.mk (_update_required): Skip automatic rerun of bootstrap if
we can't use git.
* docs/compiling.html.in: Document this setup.
* docs/hacking.html.in: Mention this.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

The previous handling of <a> tags led to some less-than-ideal
layout in HACKING (most noticeable on a mid-sentence reference
to the valgrind home page).

* docs/hacking.html.in: Slight tweaks to <a> tags.
* docs/hacking1.xsl: Move <a> handling...
* docs/hacking2.xsl: ...here.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

Enforce the style cleanup in the previous patch.

* build-aux/bracket-spacing.pl: Enforce trailing spacing.
* cfg.mk (bracket-spacing-check): Tweak error wording.
* docs/hacking.html.in: Document the rule.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

While reviewing proposed VIR_STRDUP conversions, I've already noticed
several places that do:

if (str && VIR_STRDUP(dest, str) < 0)

which can be simplified by allowing str to be NULL (something that
strdup() doesn't allow).  Meanwhile, code that wants to ensure a
non-NULL dest regardless of the source can check for <= 0.

Also, make it part of the VIR_STRDUP contract that macro arguments
are evaluated exactly once.

* src/util/virstring.h (VIR_STRDUP, VIR_STRDUP_QUIET, VIR_STRNDUP)
(VIR_STRNDUP_QUIET): Improve contract.
* src/util/virstring.c (virStrdup, virStrndup): Change return
conventions.
* docs/hacking.html.in: Document this.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

VIR_APPEND_ELEMENT(array, size, elem) was not safe if the expression
for 'size' had side effects.  While no one in the current code base
was trying to pass side effects, we might as well be robust and
explicitly document our intentions.

* src/util/viralloc.c (virInsertElementsN): Add special case.
* src/util/viralloc.h (VIR_APPEND_ELEMENT): Use it.
(VIR_ALLOC, VIR_ALLOC_N, VIR_REALLOC_N, VIR_EXPAND_N)
(VIR_RESIZE_N, VIR_SHRINK_N, VIR_INSERT_ELEMENT)
(VIR_DELETE_ELEMENT, VIR_ALLOC_VAR, VIR_FREE): Document
which macros are safe in the presence of side effects.
* docs/hacking.html.in: Document this.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

The code adaptation is not done right now, but in subsequent patches.
Hence I am not implementing syntax-check rule as it would break
compilation. Developers are strongly advised to use these new macros.
They are similar to VIR_ALLOC() logic: VIR_STRDUP(dst, src) returns zero
on success, -1 otherwise. In case you don't want to report OOM error,
use the _QUIET variant of a macro.

http://www.uhv.edu/ac/newsletters/writing/grammartip2009.07.01.htm
(and several other sites) give hints that 'onto' is best used if
you can also add 'up' just before it and still make sense. In many
cases in the code base, we really want the two-word form, or even
a simplification to just 'on' or 'to'.

* docs/hacking.html.in: Use correct 'on to'.
* python/libvirt-override.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* src/util/virpci.c: Likewise.
* daemon/THREADS.txt: Use simpler 'on'.
* docs/formatdomain.html.in: Better usage.
* docs/internals/rpc.html.in: Likewise.
* src/conf/domain_event.c: Likewise.
* src/rpc/virnetclient.c: Likewise.
* tests/qemumonitortestutils.c: Likewise.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

To tell libvirt-{qemu,lxc}.h shouldn't be included either.

To enable locking to be introduced to the security manager
objects later, turn virSecurityManager into a virObjectLockable
class
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Adding dots inside "exempli gratia" where missing.  While on that, I
took the liberty of changing it where found with simple grep.

There are many aspects of the guest XML which result in the
SELinux driver applying file labelling. With the increasing
configuration options it is desirable to test this behaviour.
It is not possible to assume that the test suite has the
ability to set SELinux labels. Most filesystems though will
support extended attributes. Thus for the purpose of testing,
it is possible to extend the existing LD_PRELOAD hack to
override setfilecon() and getfilecon() to simply use the
'user.libvirt.selinux' attribute for the sake of testing.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

I've noticed a number of people sending patches with file
renames not compressed, so we might as well document how to
set this up.  (Git won't do it by default, for back-compat
reasons)

* docs/hacking.html.in: Add git config tip.
* HACKING: Regenerate.

Based on a suggestion by John Ferlan:
https://www.redhat.com/archives/libvir-list/2013-January/msg00158.html

* docs/hacking.html.in: Add some commit message instructions.
Mention the ./run script.
* HACKING: Regenerate.

This documents the following whitespace rules

      if(foo)   // Bad
      if (foo)  // Good

      int foo (int wizz)  // Bad
      int foo(int wizz)   // Good

      bar = foo (wizz);  // Bad
      bar = foo(wizz);   // Good

      typedef int (*foo) (int wizz);  // Bad
      typedef int (*foo)(int wizz);   // Good

      int foo( int wizz );  // Bad
      int foo(int wizz);    // Good

There is a syntax-check rule extension to validate all these rules.
Checking for 'function (...args...)' is quite difficult since it
needs to ignore valid usage with keywords like 'if (...test...)'
and while/for/switch. It must also ignore source comments and
quoted strings.

It is not possible todo this with a simple regex in the normal
syntax-check style. So a short Perl script is created instead
to analyse the source. In practice this works well enough. The
only thing it can't cope with is multi-line quoted strings of
the form

 "start of string\
more lines\
more line\
the end"

but this can and should be written as

 "start of string"
 "more lines"
 "more line"
 "the end"

with this simple change, the bracket checking script does not
have any false positives across libvirt source, provided it
is only run against .c files. It is not practical to run it
against .h files, since those use whitespace extensively to
get alignment (though this is somewhat inconsistent and could
arguably be fixed).

The only limitation is that it cannot detect a violation where
the first arg starts with a '*', eg

   foo(*wizz);

since this generates too many false positives on function
typedefs which can't be supressed efficiently.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

--enable-compile-warnings=error has been renamed to --enable-werror so
update the HACKING and the hacking.html to reflect that.

* HACKING: Regenerate.

An email came to libvir-list wondering why the git send-email command
was missing in spite of having git installed; this is due to the
send-email command being in a sub-package of the main git package.

While touching the hacking file, I thought it would be useful to 1)
indicate the location of the source (docs/hacking.html.in) in the
message at the top of HACKING, and also to make the note about running
"make check" and "make syntax-check" a bit more stern.

We should really advise (new) developers to send rebased patches
that apply cleanly and use git-send-email rather than all other
obscure ways.

In preparation for a future patch adding new virFile APIs.

* src/util/files.h, src/util/files.c: Move...
* src/util/virfile.h, src/util/virfile.c: ...here, and rename
functions to virFile prefix.  Macro names are intentionally
left alone.
* *.c: All '#include "files.h"' uses changed.
* src/Makefile.am (UTIL_SOURCES): Reflect rename.
* cfg.mk (exclude_file_name_regexp--sc_prohibit_close): Likewise.
* src/libvirt_private.syms: Likewise.
* docs/hacking.html.in: Likewise.
* HACKING: Regenerate.

We already have virAsprintf, so picking a similar name helps for
seeing a similar purpose.  Furthermore, the prefix V before printf
generally implies 'va_list', even though this variant was '...', and
the old name got in the way of adding a new va_list version.

global rename performed with:

$ git grep -l virBufferVSprintf \
  | xargs -L1 sed -i 's/virBufferVSprintf/virBufferAsprintf/g'

then revert the changes in ChangeLog-old.

* docs/hacking.html.in (Code formatting): Document that // comment
and declaration-after-statement are discouraged.
* HACKING: Regenerate.

* docs/hacking.html.in (Curly braces): Tighten recommendations to
disallow if (cond) one-line; else { block; }.
* HACKING: Regenerate.
Suggested by Daniel P. Berrange.

* daemon/libvirtd.c (qemudRunLoop): Pass allocation size, not
current count, to VIR_SHRINK_N.
* docs/hacking.html.in: Update doc example.
* HACKING: Regenerate.

* src/util/memory.h (VIR_RESIZE_N): New macro.
* src/util/memory.c (virResizeN): New function.
* src/libvirt_private.syms: Export new helper.
* docs/hacking.html.in: Document it.
* HACKING: Regenerate.

* src/util/memory.h (VIR_REALLOC_N): Update docs.
(VIR_EXPAND_N, VIR_SHRINK_N): New macros.
(virAlloc, virAllocN, virReallocN, virAllocVar, virFree): Add some
gcc attributes.
* src/util/memory.c (virExpandN, virShrinkN): New functions.
(virReallocN): Update docs.
* src/libvirt_private.syms: Export new helpers.
* docs/hacking.html.in: Prefer newer interfaces over
VIR_REALLOC_N, since uninitialized memory can bite us.
* HACKING: Regenerate.

* cfg.mk (sc_prohibit_sprintf): New rule.
(sc_prohibit_asprintf): Avoid false positives.
* docs/hacking.html.in (Printf-style functions): Document the
policy.
* HACKING: Regenerate.
* .x-sc_prohibit_sprintf: New exemptions.
* Makefile.am (syntax_check_exceptions): Ship new file.
* src/vbox/vbox_tmpl.c (vboxStartMachine, vboxAttachUSB): Use
virAsprintf instead.
* src/uml/uml_driver.c (umlOpenMonitor): Use snprintf instead.
* tools/virsh.c (cmdDetachInterface): Likewise.
* src/security/security_selinux.c (SELinuxGenSecurityLabel):
Likewise.
* src/openvz/openvz_driver.c (openvzDomainDefineCmd): Likewise,
and ensure large enough buffer.

Similarly to deprecating close(), I am now deprecating fclose() and
introduce VIR_FORCE_FCLOSE() and VIR_FCLOSE(). Also, fdopen() is replaced with
VIR_FDOPEN().

Most of the files are opened in read-only mode, so usage of
VIR_FORCE_CLOSE() seemed appropriate. Others that are opened in write
mode already had the fclose()<  0 check and I converted those to
VIR_FCLOSE()<  0.

I did not find occurrences of possible double-closed files on the way.

Since bugs due to double-closed file descriptors are difficult to track down in a multi-threaded system, I am introducing the VIR_CLOSE(fd) macro to help avoid mistakes here.

There are lots of places where close() is being used. In this patch I am only cleaning up usage of close() in src/conf where the problems were.

I also dare to declare close() as being deprecated in libvirt code base (HACKING).

* docs/hacking.html.in: Use the "curly braces" section from coreutils'
HACKING, adapting for libvirt's different formatting style.
* HACKING: Sync from the above, still mostly manually.

* HACKING: Mark as read-only.  Soon we'll generate it from...
* docs/hacking.html.in: ... this file.  More typo fixes.

* HACKING: More spelling/typo fixes.

* doc/hacking.html.in (preprocessor): New section to document
recently-discussed style issues.
Signed-off-by: NEric Blake <eblake@redhat.com>