On Thursday, 12 October 2023, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> The following testcase started FAILing recently after the
>
https://sourceware.org/git/?p=glibc.git;a=commit;h=64b1a44183a3094672ed304532bedb9acc707554
> glibc change which marked vfscanf with nonnull (1) attribute.
> While vfwscanf hasn't been marked similarly (strangely), the patch changes
> that too.  By using va_arg one hides the value of it from the compiler
> (volatile keyword would do too, or making the FILE* stream a function
> argument, but then it might need to be guarded by #if or something).
>
> Tested on x86_64-linux, ok for trunk?

OK, thanks.

>
> 2023-10-12  Jakub Jelinek  <jakub@redhat.com>
>
>         * testsuite/tr1/8_c_compatibility/cstdio/functions.cc (test01):
>         Initialize stream to va_arg(ap, FILE*) rather than 0.
>         * testsuite/tr1/8_c_compatibility/cwchar/functions.cc (test01):
>         Likewise.
>
> --- libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdio/functions.cc.jj
2023-01-16 23:19:06.651711546 +0100
> +++ libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdio/functions.cc
2023-10-12 09:46:28.695011763 +0200
> @@ -35,7 +35,7 @@ void test01(int dummy, ...)
>    char* s = 0;
>    const char* cs = 0;
>    const char* format = "%i";
> -  FILE* stream = 0;
> +  FILE* stream = va_arg(ap, FILE*);
>    std::size_t n = 0;
>
>    int ret;
> --- libstdc++-v3/testsuite/tr1/8_c_compatibility/cwchar/functions.cc.jj
2023-01-16 23:19:06.651711546 +0100
> +++ libstdc++-v3/testsuite/tr1/8_c_compatibility/cwchar/functions.cc
2023-10-12 09:46:19.236141897 +0200
> @@ -42,7 +42,7 @@ void test01(int dummy, ...)
>  #endif
>
>  #if _GLIBCXX_HAVE_VFWSCANF
> -  FILE* stream = 0;
> +  FILE* stream = va_arg(arg, FILE*);
>    const wchar_t* format1 = 0;
>    int ret1;
>    ret1 = std::tr1::vfwscanf(stream, format1, arg);
>
>         Jakub
>
>