[Qemu-devel] [PATCH 00/12] qemu-common.h/osdep.h refactoring

[Peter Maydell <peter.maydell@linaro.org>]

This series makes a start at cleaning up some of our headers
to avoid the common problem of header files including qemu-common.h
(which then in turn can lead to awkward circular includes).

One common cause of this is that we don't have any header
which will include the basic things most header files require,
except for qemu-common.h. This series fixes that by making
'osdep.h' that "common basic stuff" header. The idea is that:
 * osdep.h can be included from anywhere, since it doesn't
   include any other QEMU headers itself except a few very
   restricted special purpose ones (config-host.h, compiler.h, etc)
 * osdep.h provides:
   + things everybody needs, like NULL, int32_t, container_of,
     the CONFIG_* defines, etc
   + things that will cause subtle problems if they're not
     present everywhere (eg directly using system headers and
     not getting the portability fixups will result in something
     that builds on most but not all hosts)

So most places can just include osdep.h, not the full qemu-common.h.

(I initially thought about defining a new header for this
purpose, "qemu/basics.h" or some such, but in fact osdep.h
was already very close to what I wanted so it didn't really
seem like it was very useful to switch everything over.)

The series has some minor cleanups, some shuffling around of
things between qemu-common.h, osdep.h and compiler.h, and
a couple of patches at the end that use osdep.h to allow
dropping a qemu-common.h include from various header files,
as a demonstration.

The real question here I guess is whether people like the
direction I'm trying to go with this. If so, we can further
reduce the number of qemu-common.h includes without too much
difficulty with further patches.

A cleanup deferred for the future is that osdep.h (in addition
to the stuff listed above) also has a pile of prototypes for
various functions that could reasonably be split out to their
own header files, since they're not critically important to
provide everywhere.

host-utils.h is rather misnamed these days, incidentally, but
a header rename doesn't seem really worth the effort (and I
couldn't think of a better name anyway).


Compile-tested on Linux, OSX, Windows and FreeBSD.

Peter Maydell (12):
  qapi/qmp-event.c: Don't manually include os-win32.h/os-posix.h
  osdep.h: Remove qemu_printf
  osdep.h: Move some compiler-specific things to compiler.h
  compiler.h: Use glue() in QEMU_BUILD_BUG_ON define
  qemu-common.h: Move Win32 fixups into os-win32.h
  osdep.h: Move some OS header includes and fixups from qemu-common.h
  osdep.h: Add header comment
  qemu-common.h: Move muldiv64() to host-utils.h
  apic_internal.h: Include cpu.h directly
  timer.h: Don't include qemu-common.h
  event_notifier.h: Don't include qemu-common.h
  throttle.h: Don't include qemu-common.h

 include/hw/i386/apic_internal.h |   1 +
 include/qemu-common.h           | 103 +------------------------------------
 include/qemu/compiler.h         |  51 ++++++++++++++++--
 include/qemu/event_notifier.h   |   7 +--
 include/qemu/host-utils.h       |  29 +++++++++++
 include/qemu/osdep.h            | 111 ++++++++++++++++++++++++----------------
 include/qemu/throttle.h         |   4 +-
 include/qemu/timer.h            |   4 +-
 include/sysemu/os-win32.h       |  18 +++++++
 monitor.c                       |   4 +-
 qapi/qmp-event.c                |   8 ---
 user-exec.c                     |   4 +-
 12 files changed, 175 insertions(+), 169 deletions(-)

-- 
1.9.1