Re: [PATCH users/roland/gold-charnn] gold: Use char16_t, char32_t instead of uint16_t, uint32_t as character types

[Roland McGrath <mcgrathr@google.com>]

The top-level configure already uses AX_CXX_COMPILE_STDCXX(11), which
should ensure `-std=c++11` is added if needed.  Perhaps either that
check is not having the result that it should in your configuration,
or the flags it sets are not being properly plumbed down to the
subdirectory configure/makefile flags.  For example, gdb/configure.ac
also does this itself and I'm not sure if that means that each
subdirectory configure.ac needs it as well. It seems likely that we
now need to change the invocation to be AX_CXX_COMPILE_STDCXX(11, ,
mandatory) as gdb/configure.ac does.

On Thu, Oct 19, 2023 at 4:08 AM Vaseeharan Vinayagamoorthy
<Vaseeharan.Vinayagamoorthy@arm.com> wrote:
>
> Hi,
>
> Sorry for the delayed response.
> Using -std=gnu++11 in our build scripts when building binutils does fix the issue for us, as mentioned in https://sourceware.org/bugzilla/show_bug.cgi?id=30867 .
> However, does this need fixing in configure.ac instead?
>
> Kind regards,
> Vasee
> ________________________________
> From: Roland McGrath <mcgrathr@google.com>
> Sent: 20 September 2023 01:41
> To: Vaseeharan Vinayagamoorthy <Vaseeharan.Vinayagamoorthy@arm.com>
> Cc: Binutils <binutils@sourceware.org>
> Subject: Re: [PATCH users/roland/gold-charnn] gold: Use char16_t, char32_t instead of uint16_t, uint32_t as character types
>
> I didn't realize that building gold with compilers so old they don't
> support C++11 was supported.  The GCC source history suggests that
> char16_t and char32_t support were introduced in GCC 4.4.  I'm not
> sure when the default C++ mode was changed to be >= -std=c++11.  It
> looks to me that the configure stuff should be making it pass
> `-std=c++11` if that's required, but I don't know how that test is
> coming out in your build.  I wonder if using `CXX=g++ -std=c++11`
> makes a difference with your version.