[Qemu-devel] Re: [PULL] More format checking

[Stefan Weil <weil@mail.berlios.de>]

Am 04.12.2010 21:18, schrieb Blue Swirl:
> On Sat, Dec 4, 2010 at 7:24 PM, Stefan Weil <weil@mail.berlios.de> wrote:
>> Am 04.12.2010 19:35, schrieb Blue Swirl:
>>>
>>> On Wed, Dec 1, 2010 at 9:41 PM, Stefan Weil <weil@mail.berlios.de> 
>>> wrote:
>>>>
>>>> Am 24.11.2010 22:46, schrieb Stefan Weil:
>>>>>
>>>>> Hello,
>>>>>
>>>>> with these patches, hopefully all functions with printf like arguments
>>>>> use gcc's format checking, so the TODO comment in HACKING can be
>>>>> removed.
>>>>>
>>>>> The patch series was tested with a default build configuration on 
>>>>> linux
>>>>> and windows hosts (including some cross compilations for arm, mips and
>>>>> powerpc),
>>>>> so chances are good that there remain few (if any) functions without
>>>>> format checking.
>>>>>
>>>>> If there remain such functions (and maybe also some related format
>>>>> bugs),
>>>>> the compiler will raise a warning now, so it should be easy to fix 
>>>>> them.
>>>>>
>>>>> All patches were published on qemu-devel. There were two replies:
>>>>>
>>>>> * 1st patch: small typo in commit message, fixed now
>>>>>
>>>>> * last patch: breaks build
>>>>>
>>>>> It's normal that the last patch will break builds with warning = error
>>>>> as long as the other four patches (and maybe more format related 
>>>>> fixes)
>>>>> are not applied. This is the intention of the last patch!
>>>>>
>>>>> Regards,
>>>>> Stefan Weil
>>>>>
>>>>> The following changes since commit
>>>>> f711df67d611e4762966a249742a5f7499e19f99:
>>>>>
>>>>>  microblaze: target-ify target_ucontext (2010-11-23 10:04:30 +0100)
>>>>>
>>>>> are available in the git repository at:
>>>>>  git://git.weilnetz.de/git/qemu for-blueswirl
>>>>>
>>>>> Stefan Weil (5):
>>>>>     *-dis: Replace fprintf_ftype by fprintf_function (format checking)
>>>>>     target-sparc: Use fprintf_function (format checking)
>>>>>     audio: Use GCC_FMT_ATTR (format checking)
>>>>>     darwin-user: Use GCC_FMT_ATTR (format checking)
>>>>>     configure: Add compiler option -Wmissing-format-attribute
>>>>>
>>>>>  HACKING                |    3 ---
>>>>>  alpha-dis.c            |    3 +++
>>>>>  arm-dis.c              |   14 +++++++-------
>>>>>  audio/audio_pt_int.c   |    3 ++-
>>>>>  configure              |    1 +
>>>>>  darwin-user/machload.c |    2 +-
>>>>>  darwin-user/qemu.h     |    2 +-
>>>>>  dis-asm.h              |   10 ++--------
>>>>>  m68k-dis.c             |    2 +-
>>>>>  microblaze-dis.c       |    2 +-
>>>>>  mips-dis.c             |    2 --
>>>>>  sh4-dis.c              |   16 +++++-----------
>>>>>  target-sparc/cpu.h     |    4 ++--
>>>>>  13 files changed, 26 insertions(+), 38 deletions(-)
>>>>>
>>>>
>>>>
>>>> Is there anything missing, or can the patch series be applied finally?
>>>
>>> The last patch is not OK yet:
>>> CC qemu-img.o
>>> /src/qemu/qemu-img.c: In function 'error':
>>> /src/qemu/qemu-img.c:48:5: error: function might be possible candidate
>>> for 'ms_printf' format attribute [-Werror=missing-format-attribute]
>>> CC qemu-error.o
>>> /src/qemu/qemu-error.c: In function 'error_vprintf':
>>> /src/qemu/qemu-error.c:27:9: error: function might be possible
>>> candidate for 'ms_printf' format attribute
>>> [-Werror=missing-format-attribute]
>>> CC block/blkverify.o
>>> /src/qemu/block/blkverify.c: In function 'blkverify_err':
>>> /src/qemu/block/blkverify.c:65:5: error: function might be possible
>>> candidate for 'ms_printf' format attribute
>>> [-Werror=missing-format-attribute]
>>> CC json-parser.o
>>> /src/qemu/json-parser.c: In function 'parse_error':
>>> /src/qemu/json-parser.c:100:5: error: function might be possible
>>> candidate for 'ms_printf' format attribute
>>> [-Werror=missing-format-attribute]
>>> CC qerror.o
>>> /src/qemu/qerror.c: In function 'qerror_abort':
>>> /src/qemu/qerror.c:230:5: error: function might be possible candidate
>>> for 'ms_printf' format attribute [-Werror=missing-format-attribute]
>>> CC blockdev.o
>>> /src/qemu/blockdev.c: In function 'drive_add':
>>> /src/qemu/blockdev.c:52:5: error: function might be possible candidate
>>> for 'ms_printf' format attribute [-Werror=missing-format-attribute]
>>> CC qemu-char.o
>>> /src/qemu/qemu-char.c: In function 'qemu_chr_printf':
>>> /src/qemu/qemu-char.c:182:5: error: function might be possible
>>> candidate for 'ms_printf' format attribute
>>> [-Werror=missing-format-attribute]
>>> CC audio/audio.o
>>> /src/qemu/audio/audio.c: In function 'AUD_vlog':
>>> /src/qemu/audio/audio.c:346:9: error: function might be possible
>>> candidate for 'ms_printf' format attribute
>>> [-Werror=missing-format-attribute]
>>>
>>> This is with mingw32 compiler, it should be happy with gnu_printf
>>> instead of ms_printf in case you wonder that.
>>
>> As far as I know all those warnings are false warnings.
>
> No, for example qemu-img.c and blockdev.c cases are real. I don't
> understand blkverify.c and qerror cases, GCC_FMT_ATTR() attributes are
> in place.

I'm sorry but I don't understand your "no".

My patches added the necessary format attributes in qemu-img.c
and blockdev.c (otherwise all builds would raise compiler warnings).

It's a mingw32 problem that the compiler complains there.
This is what I call a "false" warning.

Where did you detect a missing format attribute?