Re: [PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr

[Konstantin Kostiuk <kkostiuk@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 4884 bytes --]

On Fri, Jul 7, 2023 at 6:36 PM Philippe Mathieu-Daudé <philmd@linaro.org>
wrote:

> On 7/7/23 16:24, Konstantin Kostiuk wrote:
> >
> >
> > On Fri, Jul 7, 2023 at 1:33 PM Philippe Mathieu-Daudé <philmd@linaro.org
> > <mailto:philmd@linaro.org>> wrote:
> >
> >     On 7/7/23 11:22, Konstantin Kostiuk wrote:
> >      > Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com
> >     <mailto:kkostiuk@redhat.com>>
> >      > ---
> >      >   qga/vss-win32/meson.build   |  2 +-
> >      >   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
> >      >   qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
> >      >   3 files changed, 57 insertions(+), 1 deletion(-)
> >      >   create mode 100644 qga/vss-win32/vss-debug.cpp
> >      >   create mode 100644 qga/vss-win32/vss-debug.h
> >
> >
> >      > diff --git a/qga/vss-win32/vss-debug.cpp
> >     b/qga/vss-win32/vss-debug.cpp
> >      > new file mode 100644
> >      > index 0000000000..5d6f37944b
> >      > --- /dev/null
> >      > +++ b/qga/vss-win32/vss-debug.cpp
> >      > @@ -0,0 +1,31 @@
> >      > +/*
> >      > + * QEMU Guest Agent VSS debug declarations
> >      > + *
> >      > + * Copyright (C) 2023 Red Hat Inc
> >      > + *
> >      > + * Authors:
> >      > + *  Konstantin Kostiuk <kkostiuk@redhat.com
> >     <mailto:kkostiuk@redhat.com>>
> >      > + *
> >      > + * This work is licensed under the terms of the GNU GPL, version
> >     2 or later.
> >      > + * See the COPYING file in the top-level directory.
> >      > + */
> >      > +
> >      > +#include "qemu/osdep.h"
> >      > +#include "vss-debug.h"
> >      > +#include "vss-common.h"
> >      > +
> >      > +void qga_debug_internal(const char *funcname, const char *fmt,
> >     ...)  {
> >      > +    char user_sting[512] = {0};
> >
> >     "user_string"
> >
> >      > +    char full_string[640] = {0};
> >      > +
> >      > +    va_list args;
> >      > +    va_start(args, fmt);
> >      > +    vsnprintf(user_sting, 512, fmt, args);
> >
> >     ARRAY_SIZE(user_string)
> >
> >
> > I have a problem with ARRAY_SIZE define.
> >
> > ../qga/vss-win32/vss-debug.cpp: In function 'void
> > qga_debug_internal(const char*, const char*, ...)':
> > /src/include/qemu/compiler.h:70:12: error: types may not be defined in
> > 'sizeof' expressions
> >     70 |     struct { \
> >        |            ^
> > /src/include/qemu/compiler.h:78:43: note: in expansion of macro
> > 'QEMU_BUILD_BUG_ON_STRUCT'
> >     78 | #define QEMU_BUILD_BUG_ON_ZERO(x)
> > (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
> >        |
> ^~~~~~~~~~~~~~~~~~~~~~~~
> > /src/include/qemu/osdep.h:474:24: note: in expansion of macro
> > 'QEMU_BUILD_BUG_ON_ZERO'
> >    474 |
>  QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> >        |                        ^~~~~~~~~~~~~~~~~~~~~~
> > ../qga/vss-win32/vss-debug.cpp:23:32: note: in expansion of macro
> > 'ARRAY_SIZE'
> >     23 |     if (vsnprintf(user_string, ARRAY_SIZE(user_string), fmt,
> > args) <= 0) {
> >        |                                ^~~~~~~~~~
> > /src/include/qemu/osdep.h:470:57: error: expected primary-expression
> > before 'typeof'
> >    470 | #define QEMU_IS_ARRAY(x)
> > (!__builtin_types_compatible_p(typeof(x), \
> >        |                                                         ^~~~~~
> > /src/include/qemu/compiler.h:71:14: note: in definition of macro
> > 'QEMU_BUILD_BUG_ON_STRUCT'
> >     71 |         int:(x) ? -1 : 1; \
> >        |              ^
> > /src/include/qemu/osdep.h:474:24: note: in expansion of macro
> > 'QEMU_BUILD_BUG_ON_ZERO'
> >    474 |
>  QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> >        |                        ^~~~~~~~~~~~~~~~~~~~~~
> > /src/include/qemu/osdep.h:474:48: note: in expansion of macro
> > 'QEMU_IS_ARRAY'
> >    474 |
>  QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> >
> > Can you help with this?
>
> Eh no clue, maybe not C++ compliant?
>
> Fall back to sizeof() ¯\_(ツ)_/¯
>
>
You are right, When I rename the file to vss-debug.c the error disappears.
What is the better solution:
1) use vss-debug.c and extern "C" { #include "vss-debug.h" } in CPP files
2) just use sizeof() in CPP


> >
> >
> >      > +    va_end(args);
> >      > +
> >      > +    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s
> %s\n",
> >      > +             GetCurrentThreadId(), funcname, user_sting);
> >
> >     if (snprintf() <= 0) { return; }
> >
> >      > +
> >      > +    OutputDebugString(full_string);
> >      > +    fprintf(stderr, "%s", full_string);
> >
> >     Format unused:
> >
> >     fputs(full_string, stderr);
> >
> >      > +}
> >
> >     With the changes:
> >     Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org
> >     <mailto:philmd@linaro.org>>
> >
>
>

[-- Attachment #2: Type: text/html, Size: 7334 bytes --]