[Bug c++/109283] New: Destructor of co_yield conditional argument called twice

[ncm at cantrip dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109283

            Bug ID: 109283
           Summary: Destructor of co_yield conditional argument called
                    twice
           Product: gcc
           Version: 12.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ncm at cantrip dot org
  Target Milestone: ---

Created attachment 54754
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54754&action=edit
Reproducer

Basically:

  co_yield a ? s : t;

segfaults,

  if (a) co_yield s; else co_yield t;

does not. The segfault traces to s/t's destructor being called 
twice. Full reproducer attached, relying on Casey Carter's 
generator implementation, pasted in.

This may be related to 101367.

Compiled with gcc-12.2, this program segfaults.
Compiled with gcc-trunk or gcc-coroutines on Godbolt, identified as:

  g++
(Compiler-Explorer-Build-gcc-13ec81eb4c3b484ad636000fa8f6d925e15fb983-binutils-2.38)
13.0.1 20230325 (experimental)

the compiler ICEs:

  <source>:513:1: internal compiler error: in flatten_await_stmt, at
cp/coroutines.cc:2899
  513 | }