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2562755ee7
The point of writing a macro embedded in a 'do { ... } while (0)'
loop (particularly if the macro has multiple statements or would
otherwise end with an 'if' statement) is so that the macro can be
used as a drop-in statement with the caller supplying the
trailing ';'. Although our coding style frowns on brace-less 'if':
if (cond)
statement;
else
something else;
that is the classic case where failure to use do/while(0) wrapping
would cause the 'else' to pair with any embedded 'if' in the macro
rather than the intended outer 'if'. But conversely, if the macro
includes an embedded ';', then the same brace-less coding style
would now have two statements, making the 'else' a syntax error
rather than pairing with the outer 'if'. Thus, even though our
coding style with required braces is not impacted, ending a macro
with ';' makes our code harder to port to projects that use
brace-less styles.
The change should have no semantic impact. I was not able to
fully compile-test all of the changes (as some of them are
examples of the ugly bit-rotting debug print statements that are
completely elided by default, and I didn't want to recompile
with the necessary -D witnesses - cleaning those up is left as a
bite-sized task for another day); I did, however, audit that for
all files touched, all callers of the changed macros DID supply
a trailing ';' at the callsite, and did not appear to be used
as part of a brace-less conditional.
Found mechanically via: $ git grep -B1 'while (0);' | grep -A1 \\\\
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20171201232433.25193-7-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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| audio | ||
| backends | ||
| block | ||
| bsd-user | ||
| capstone@22ead3e0bf | ||
| chardev | ||
| contrib | ||
| crypto | ||
| default-configs | ||
| disas | ||
| docs | ||
| dtc@e54388015a | ||
| fpu | ||
| fsdev | ||
| gdb-xml | ||
| hw | ||
| include | ||
| io | ||
| libdecnumber | ||
| linux-headers | ||
| linux-user | ||
| migration | ||
| nbd | ||
| net | ||
| pc-bios | ||
| po | ||
| qapi | ||
| qga | ||
| qobject | ||
| qom | ||
| replay | ||
| roms | ||
| scripts | ||
| scsi | ||
| slirp | ||
| stubs | ||
| target | ||
| tcg | ||
| tests | ||
| trace | ||
| ui | ||
| util | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .exrc | ||
| .gdbinit | ||
| .gitignore | ||
| .gitmodules | ||
| .mailmap | ||
| .shippable.yml | ||
| .travis.yml | ||
| arch_init.c | ||
| balloon.c | ||
| block.c | ||
| blockdev-nbd.c | ||
| blockdev.c | ||
| blockjob.c | ||
| bootdevice.c | ||
| bt-host.c | ||
| bt-vhci.c | ||
| Changelog | ||
| CODING_STYLE | ||
| configure | ||
| COPYING | ||
| COPYING.LIB | ||
| COPYING.PYTHON | ||
| cpus-common.c | ||
| cpus.c | ||
| device-hotplug.c | ||
| device_tree.c | ||
| disas.c | ||
| dma-helpers.c | ||
| dump.c | ||
| exec.c | ||
| gdbstub.c | ||
| HACKING | ||
| hmp-commands-info.hx | ||
| hmp-commands.hx | ||
| hmp.c | ||
| hmp.h | ||
| ioport.c | ||
| iothread.c | ||
| LICENSE | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.objs | ||
| Makefile.target | ||
| memory.c | ||
| memory_ldst.inc.c | ||
| memory_mapping.c | ||
| module-common.c | ||
| monitor.c | ||
| numa.c | ||
| os-posix.c | ||
| os-win32.c | ||
| qapi-schema.json | ||
| qdev-monitor.c | ||
| qdict-test-data.txt | ||
| qemu-bridge-helper.c | ||
| qemu-doc.texi | ||
| qemu-ga.texi | ||
| qemu-img-cmds.hx | ||
| qemu-img.c | ||
| qemu-img.texi | ||
| qemu-io-cmds.c | ||
| qemu-io.c | ||
| qemu-keymap.c | ||
| qemu-nbd.c | ||
| qemu-nbd.texi | ||
| qemu-option-trace.texi | ||
| qemu-options-wrapper.h | ||
| qemu-options.h | ||
| qemu-options.hx | ||
| qemu-seccomp.c | ||
| qemu-tech.texi | ||
| qemu.nsi | ||
| qemu.sasl | ||
| qmp.c | ||
| qtest.c | ||
| README | ||
| replication.c | ||
| replication.h | ||
| rules.mak | ||
| thunk.c | ||
| tpm.c | ||
| trace-events | ||
| VERSION | ||
| version.rc | ||
| vl.c | ||
QEMU README
===========
QEMU is a generic and open source machine & userspace emulator and
virtualizer.
QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).
QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.
QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.
QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.
Building
========
QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:
mkdir build
cd build
../configure
make
Additional information can also be found online via the QEMU website:
https://qemu.org/Hosts/Linux
https://qemu.org/Hosts/Mac
https://qemu.org/Hosts/W32
Submitting patches
==================
The QEMU source code is maintained under the GIT version control system.
git clone git://git.qemu.org/qemu.git
When submitting patches, the preferred approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the HACKING and CODING_STYLE files.
Additional information on submitting patches can be found online via
the QEMU website
https://qemu.org/Contribute/SubmitAPatch
https://qemu.org/Contribute/TrivialPatches
Bug reporting
=============
The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:
https://bugs.launchpad.net/qemu/
If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via launchpad.
For additional information on bug reporting consult:
https://qemu.org/Contribute/ReportABug
Contact
=======
The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC
- qemu-devel@nongnu.org
https://lists.nongnu.org/mailman/listinfo/qemu-devel
- #qemu on irc.oftc.net
Information on additional methods of contacting the community can be
found online via the QEMU website:
https://qemu.org/Contribute/StartHere
-- End