https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98675
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:9fdbd7d6fa5e0a76898dd66658934e3184111680 commit r14-2773-g9fdbd7d6fa5e0a76898dd66658934e3184111680 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Sun Jul 23 01:15:14 2023 +1000 c++: Track lifetimes in constant evaluation [PR70331,PR96630,PR98675] This adds rudimentary lifetime tracking in C++ constexpr contexts, allowing the compiler to report errors with using values after their backing has gone out of scope. We don't yet handle other ways of accessing values outside their lifetime (e.g. following explicit destructor calls). PR c++/96630 PR c++/98675 PR c++/70331 gcc/cp/ChangeLog: * constexpr.cc (constexpr_global_ctx::is_outside_lifetime): New function. (constexpr_global_ctx::get_value): Don't return expired values. (constexpr_global_ctx::get_value_ptr): Likewise. (constexpr_global_ctx::remove_value): Mark value outside lifetime. (outside_lifetime_error): New function. (cxx_eval_call_expression): No longer track save_exprs. (cxx_eval_loop_expr): Likewise. (cxx_eval_constant_expression): Add checks for outside lifetime values. Remove local variables at end of bind exprs, and temporaries after cleanup points. gcc/testsuite/ChangeLog: * g++.dg/cpp1y/constexpr-lifetime1.C: New test. * g++.dg/cpp1y/constexpr-lifetime2.C: New test. * g++.dg/cpp1y/constexpr-lifetime3.C: New test. * g++.dg/cpp1y/constexpr-lifetime4.C: New test. * g++.dg/cpp1y/constexpr-lifetime5.C: New test. * g++.dg/cpp1y/constexpr-lifetime6.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
