This improves the output for issue #72577, but there's still more work
to be done.
Currently, an overflow error during monomorphization results in an error
that points at the function we were unable to monomorphize. However, we
don't point at the call that caused the monomorphization to happen. In
the overflow occurs in a large recursive function, it may be difficult
to determine where the issue is.
This commit tracks and `Span` information during collection of
`MonoItem`s, which is used when emitting an overflow error. `MonoItem`
itself is unchanged, so this only affects
`src/librustc_mir/monomorphize/collector.rs`
Miri: avoid tracking current location three times
Miri tracks the current instruction to execute in the call stack, but it also additionally has two `TyCtxtAt` that carry a `Span` that also tracks the current instruction. That is quite silly, so this PR uses `TyCtxt` instead, and then uses a method for computing the current span when a `TyCtxtAt` is needed. Having less redundant (semi-)global state seems like a good improvement to me. :D
To keep the ConstProp errors the same, I had to add the option to `error_to_const_error` to overwrite the span. Also for some reason this changes cycle errors a bit -- not sure if we are now better or worse as giving those queries the right span. (It is unfortunately quite easy to accidentally use `DUMMY_SP` by calling the query on a `TyCtxt` instead of a `TyCtxtAt`.)
r? @oli-obk @eddyb
Previously, we threw away the `Span` associated with a definition's
identifier when we encoded crate metadata, causing us to lose location
and hygiene information.
We now store the identifier's `Span` in the crate metadata.
When we decode items from the metadata, we combine
the name and span back into an `Ident`.
This improves the output of several tests, which previously had messages
suppressed due to dummy spans.
This is a prerequisite for #68686, since throwing away a `Span` means
that we lose hygiene information.
This is one of the behaviors we no longer allow in NLL. Since it can
lead to undefined behavior, I think it's definitely worth making it a
hard error without waiting to turn off migration mode (#58781).
Closes#60450.
My ulterior motive here is making it impossible to leave variables
partially initialized across a yield (see discussion at #63035), so
tests are included for that.
Don't stop evaluating due to errors before borrow checking
r? @oli-obk
Fix#60005. Follow up to #59903. Blocked on #53708, fixing the ICE in `src/test/ui/consts/match_ice.rs`.
