On date Monday 2023-12-18 19:05:17 -0300, James Almer wrote:
> On 12/18/2023 5:54 AM, Martin Storsjö wrote:
> > Converting from an integer to HWND (which is a pointer) requires
> > an explicit cast, otherwise Clang errors out like this:
> >
> > src/libavdevice/gdigrab.c:280:14: error: incompatible integer to
> > pointer conversion assigning to 'HWND' (aka 'struct HWND__ *') from 'long'
> > [-Wint-conversion]
> > 280 | hwnd = strtol(name, &p, 0);
> > | ^ ~~~~~~~~~~~~~~~~~~~
> >
> > (With GCC and MSVC, this was a mere warning, but with recent Clang,
> > this is an error.)
> >
> > After adding a cast, all compilers also warn something like this:
> >
> > src/libavdevice/gdigrab.c:280:16: warning: cast to 'HWND' (aka 'struct
> > HWND__ *') from smaller integer type 'long' [-Wint-to-pointer-cast]
> > 280 | hwnd = (HWND) strtol(name, &p, 0);
> > | ^~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > On Windows, long types are 32 bit, so to get a usable pointer, we
> > need to use long long. And interpret it as unsigned long long
> > while at it - i.e. using strtoull.
> >
> > Finally, right above it, the code triggered the following warning:
> >
> > src/libavdevice/gdigrab.c:278:15: warning: mixing declarations and
> > code is incompatible with standards before C99
> > [-Wdeclaration-after-statement]
> > 278 | char *p;
> > | ^
> > ---
> > libavdevice/gdigrab.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c
> > index 41ef370f2b..b2858ecd89 100644
> > --- a/libavdevice/gdigrab.c
> > +++ b/libavdevice/gdigrab.c
> > @@ -274,10 +274,10 @@ gdigrab_read_header(AVFormatContext *s1)
> > } else if (!strcmp(filename, "desktop")) {
> > hwnd = NULL;
> > } else if (!strncmp(filename, "hwnd=", 5)) {
> > - name = filename + 5;
> > char *p;
> > + name = filename + 5;
> > - hwnd = strtol(name, &p, 0);
> > + hwnd = (HWND) strtoull(name, &p, 0);
> > if (p == NULL || p == name || p[0] == '\0')
> > {
>
> Should be ok.
Also LGTM, thanks.
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