On 2/26/19 11:02 AM, Paolo Carlini wrote:
Hi,
On 26/02/19 15:28, Jason Merrill wrote:
On 2/25/19 10:27 AM, Paolo Carlini wrote:
Hi,
this error recovery regression has to do with the recent changes
committed by Jason for c++/88368. What happens is that
maybe_instantiate_noexcept fails the hard way, thus, toward the end
of the function, doesn't update TREE_TYPE (fn) and just returns
false. process_subob_fn doesn't notice and proceeds to call
merge_exception_specifiers anyway where of course the gcc_assert
(!DEFERRED_NOEXCEPT_SPEC_P (add)) triggers, because
maybe_instantiate_noexcept has not done its normal job. To improve
error-recovery I think we can simply leave *spec_p alone in such
cases, because we would merge the *spec_p with a
TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)) where TREE_TYPE (fn) has not
been normally computed. I tried a few other things which prima facie
looked sensible but nothing else worked - eg, returning false from
maybe_instantiate_noexcept and also updating TREE_TYPE (fn) to a
noexcept_false_spec variant causes regressions exactly for the
testcases of c++/88368.
If maybe_instantiate_noexcept returns false, I think we should set
*spec_p to error_mark_node.
Sure, that certainly works, I tested it a couple of days ago and I'm
finishing testing the below now. The only difference is that during
error-recovery 'zl ()' is seen as seriously broken and we don't give the
second, "cannot convert", error message, which we used to give.
OK if it passes.
Jason
