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Re: ReBuild-Depends?

"Dmitry E. Oboukhov" <unera@debian.org> writes:

> I have a package which contains a code like following:
> #include <stdio.h>
> FILE *file_handle;
> int foo(int something, const char *fmt, ...)
> {
>     // some statements
>     ....
>     va_list ap;
>     int res = vfprintf(file_handle, fmt, ap);
>     va_end(ap);
>     return res;
> }
> This code works fine by libc wouldn't be rebuilt (new versions, or new
> gcc - this moment is ambiguous to me).
> Then this code begins segfaulting into this place.
> If we try to rebuild our package, it will begin to work fine again.

Should that work at all?

man va_arg:

       Each invocation of va_start() must be matched by a corresponding  invo-
       cation of va_end() in the same function.  After the call va_end(ap) the
       variable ap is undefined.  Multiple traversals of the list, each brack-
       eted  by va_start() and va_end() are possible.  va_end() may be a macro
       or a function.

You need to call va_start() before the vfprintf or not call va_end().

Does that solve the problem?


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