[Bug libstdc++/108035] New: std::source_location::function_name() provides an empty string when used with clang++

[Bug libstdc++/108035] New: std::source_location::function_name() provides an empty string when used with clang++

[danhan at live dot ie]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108035

            Bug ID: 108035
           Summary: std::source_location::function_name() provides an
                    empty string when used with clang++
           Product: gcc
           Version: 12.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: danhan at live dot ie
  Target Milestone: ---

I ran this minimal example from cppreference
https://en.cppreference.com/w/cpp/utility/source_location

on godbolt
https://godbolt.org/z/jYMYb8ez6

and source_location::function_name() returned an empty string where if the same
code is compiled with gcc it returns what appears to be the value of
__PRETTY_FUNCTION__ for the caller of the log(...) function,
as both have __PRETTY_FUNCTION__ as an internal I would have expected the
behavior to be the same.

Consequentally I have posted this on the llvm bugtracker as well :)

https://github.com/llvm/llvm-project/issues/59422

[Bug libstdc++/108035] libstdc++ implementation of std::source_location::function_name() provides an empty string when used with clang++

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108035

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
That looks solely like a clang issue.  It implements the builtin gcc has added
for <source_location> - __builtin_source_location () - but fills in
_M_function_name
with just "" rather than a pretty name.

[Bug libstdc++/108035] libstdc++ implementation of std::source_location::function_name() provides an empty string when used with clang++

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108035

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Right, if Clang doesn't provide a name then there's nothing libstdc++ can do
about it.

[Bug libstdc++/108035] libstdc++ implementation of std::source_location::function_name() provides an empty string when used with clang++

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108035

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://github.com/llvm/llv
                   |                            |m-project/issues/59422
         Resolution|---                         |MOVED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
As mentioned there is nothing GCC's libstdc++ can be done if clang/llvm's
__builtin_source_location implementation does not fill in the function name.