Re: [PATCH] libstdc++: Tweak source_location for clang trunk [PR105128]

[Jonathan Wakely <jwakely.gcc@gmail.com>]

On Sat, 2 Apr 2022, 10:32 Jakub Jelinek via Libstdc++, <
libstdc++@gcc.gnu.org> wrote:

> Hi!
>
> Apparently clang trunk implemented __builtin_source_location(), but the
> using __builtin_ret_type = decltype(__builtin_source_location());
> which has been added for it isn't enough, they also need the
> std::source_location::__impl class to be defined (but incomplete seems
> to be good enough) before the builtin is used.
>
> The following has been tested on godbolt with clang trunk (old version
> fails with
> error: 'std::source_location::__impl' was not found; it must be defined
> before '__builtin_source_location' is called
> and some follow-up errors), getting back to just void * instead of
> __builtin_ret_type and commenting out using doesn't work either and
> just struct __impl; before using __builtin_ret_type doesn't work too.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>

OK, thanks.



> 2022-04-02  Jakub Jelinek  <jakub@redhat.com>
>
>         PR libstdc++/105128
>         * include/std/source_location (std::source_location::__impl): Move
>         definition before using __builtin_ret_type.
>
> --- libstdc++-v3/include/std/source_location    2022-02-25
> 10:46:53.275178858 +0100
> +++ libstdc++-v3/include/std/source_location    2022-04-01
> 19:36:02.056236397 +0200
> @@ -43,6 +43,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>    {
>    private:
>      using uint_least32_t = __UINT_LEAST32_TYPE__;
> +    struct __impl
> +    {
> +      const char* _M_file_name;
> +      const char* _M_function_name;
> +      unsigned _M_line;
> +      unsigned _M_column;
> +    };
>      using __builtin_ret_type = decltype(__builtin_source_location());
>
>    public:
> @@ -76,14 +83,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>      { return _M_impl ? _M_impl->_M_function_name : ""; }
>
>    private:
> -    struct __impl
> -    {
> -      const char* _M_file_name;
> -      const char* _M_function_name;
> -      unsigned _M_line;
> -      unsigned _M_column;
> -    };
> -
>      const __impl* _M_impl = nullptr;
>    };
>
>
>         Jakub
>
>