[Bug c++/89003] Return inside a statement expression while initializing a static local variable fails to cleanup cxa_guard

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89003

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
      Known to fail|                            |8.2.1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.

  _2 = __cxa_guard_acquire (&_ZGVZ1fvE1i);
  retval.1 = _2 != 0;
  if (retval.1 != 0) goto <D.2375>; else goto <D.2376>;
  <D.2375>:
  D.2370 = 0;
  try
    {
      return;
      i = 42;
      D.2370 = 1;
      __cxa_guard_release (&_ZGVZ1fvE1i);
    }
  catch
    {
      if (D.2370 != 0) goto <D.2377>; else goto <D.2378>;
      <D.2377>:
      goto <D.2379>;
      <D.2378>:
      __cxa_guard_abort (&_ZGVZ1fvE1i);
      <D.2379>:
    }

Docs for statement expressions say

"Jumping out of a statement expression is permitted, but if the
statement expression is part of a larger expression then it is
unspecified which other subexpressions of that expression have been
evaluated except where the language definition requires certain
subexpressions to be evaluated before or after the statement
expression."

so I'd say it behaves as documented since the statement expression is
part of an initialization expression which involves locking (though
not sure if that part is mandated by the standard and thus this
implementation detail shouldn't trigger the unspecified behavior).