https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33799
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:7c82dd6c02d44d9d2cd84dda137c00b1a3cd6c90 commit r10-5926-g7c82dd6c02d44d9d2cd84dda137c00b1a3cd6c90 Author: Jason Merrill <ja...@redhat.com> Date: Fri Jan 10 17:14:12 2020 -0500 PR c++/33799 - destroy return value if local cleanup throws. This is a pretty rare situation since the C++11 change to make all destructors default to noexcept, but it is still possible to define throwing destructors, and if a destructor for a local variable throws during the return, we've already constructed the return value, so now we need to destroy it. I handled this somewhat like the new-expression cleanup; as in that case, this cleanup can't properly nest with the cleanups for local variables, so I introduce a cleanup region around the whole function and a flag variable to indicate whether the return value actually needs to be destroyed. Setting the flag requires giving a COMPOUND_EXPR as the operand of a RETURN_EXPR, so I adjust gimplify_return_expr to handle that. This doesn't currently work with deduced return type because we don't know the type when we're deciding whether to introduce the cleanup region. gcc/ * gimplify.c (gimplify_return_expr): Handle COMPOUND_EXPR. gcc/cp/ * cp-tree.h (current_retval_sentinel): New macro. * decl.c (start_preparsed_function): Set up cleanup for retval. * typeck.c (check_return_expr): Set current_retval_sentinel.
