Re: [PATCH v2 12/21] block: Move qemu_fcntl_addfl() into osdep.c

[Hanna Czenczek <hreitz@redhat.com>]

On 09.06.25 17:03, Stefan Hajnoczi wrote:
> On Wed, Jun 04, 2025 at 03:28:04PM +0200, Hanna Czenczek wrote:
>> Move file-posix's helper to add a flag (or a set of flags) to an FD's
>> existing set of flags into osdep.c for other places to use.
>>
>> Suggested-by: Eric Blake <eblake@redhat.com>
>> Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
>> ---
>>   include/qemu/osdep.h |  1 +
>>   block/file-posix.c   | 17 +----------------
>>   util/osdep.c         | 18 ++++++++++++++++++
>>   3 files changed, 20 insertions(+), 16 deletions(-)
> I was curious if putting POSIX fcntl(2) in osdep.c would work on
> Windows. It does not:
>
> x86_64-w64-mingw32-gcc -m64 -Ilibqemuutil.a.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/glib-2.0 -I/usr/x86_64-w64-mingw32/sys-root/mingw/lib/glib-2.0/include -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -fstack-protector-strong -Wempty-body -Wendif-labels -Wexpansion-to-defined -Wformat-security -Wformat-y2k -Wignored-qualifiers -Wimplicit-fallthrough=2 -Winit-self -Wmissing-format-attribute -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls -Wshadow=local -Wstrict-prototypes -Wtype-limits -Wundef -Wvla -Wwrite-strings -Wno-missing-include-dirs -Wno-psabi -Wno-shift-negative-value -iquote . -iquote /home/stefanha/qemu -iquote /home/stefanha/qemu/include -iquote /home/stefanha/qemu/host/include/x86_64 -iquote /home/stefanha/qemu/host/include/generic -iquote /home/stefanha/qemu/tcg/i386 -mms-bitfields -mms-bitfields -mcx16 -msse2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -fno-pie -no-pie -ftrivial-auto-var-init=zero -fzero-call-used-regs=used-gpr -mms-bitfields -mms-bitfields -pthread -mms-bitfields -MD -MQ libqemuutil.a.p/util_osdep.c.obj -MF libqemuutil.a.p/util_osdep.c.obj.d -o libqemuutil.a.p/util_osdep.c.obj -c ../util/osdep.c
> ../util/osdep.c: In function 'qemu_fcntl_addfl':
> ../util/osdep.c:625:13: error: implicit declaration of function 'fcntl' [-Wimplicit-function-declaration]
>    625 |     flags = fcntl(fd, F_GETFL);
>        |             ^~~~~
> ../util/osdep.c:625:13: error: nested extern declaration of 'fcntl' [-Werror=nested-externs]
> ../util/osdep.c:625:23: error: 'F_GETFL' undeclared (first use in this function)
>    625 |     flags = fcntl(fd, F_GETFL);
>        |                       ^~~~~~~
> ../util/osdep.c:625:23: note: each undeclared identifier is reported only once for each function it appears in
> ../util/osdep.c:629:19: error: 'F_SETFL' undeclared (first use in this function)
>    629 |     if (fcntl(fd, F_SETFL, flags | flag) == -1) {
>        |                   ^~~~~~~
> cc1: all warnings being treated as errors

Ah, thanks!

I’ll move it up into the #ifndef _WIN32 block around qemu_dup_flags() 
and friends.

Hanna