Re: [PATCH] libstdc++: Deliver names of C functions in <stacktrace>

["François Dumont" <frs.dumont@gmail.com>]

On 12/12/22 18:56, Björn Schäpers wrote:
> From: Björn Schäpers <bjoern@hazardy.de>
>
> One could add (), these are not part of __name. One could also try to
> check upfront if __cxa_demangle should be called at all.
>
> -- >8 --
>
> Tested on i686-w64-mingw32.
>
> __cxa_demangle is only to demangle C++ names, for all C functions,
> extern "C" functions, and including main it returns -2, in that case
> just adapt the given name. Otherwise it's kept empty, which doesn't look
> nice in the stacktrace.
>
> libstdc++-v3/ChangeLog:
>
> 	* include/std/stacktrace (stacktrace_entry::_S_demangle): Use
> 	raw __name if __cxa_demangle could not demangle it.
>
> Signed-off-by: Björn Schäpers <bjoern@hazardy.de>
> ---
>   libstdc++-v3/include/std/stacktrace | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/libstdc++-v3/include/std/stacktrace b/libstdc++-v3/include/std/stacktrace
> index 83c6463b0d8..6d4051b9f5b 100644
> --- a/libstdc++-v3/include/std/stacktrace
> +++ b/libstdc++-v3/include/std/stacktrace
> @@ -217,8 +217,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>         int __status;
>         char* __str = __cxxabiv1::__cxa_demangle(__name, nullptr, nullptr,
>   					       &__status);
> -      if (__status == 0)
> +      switch (__status)
> +      {
> +      case 0:
>   	__s = __str;
> +	break;
> +      case -2:
> +	__s = __name;
> +	break;
> +      }
>         __builtin_free(__str);
>         return __s;
>       }

why not just using __name if __status != 0 ? Everything seems better 
than an empty string, no ?

This is what I've done in src/c++11/debug.cc.