Invert control in struct_lint_level.
Closes#67927
Changes the `struct_lint*` methods to take a `decorate` function instead of a message string. This decorate function is also responsible for eventually stashing, emitting or cancelling the diagnostic. If the lint was allowed after all, the decorate function is not run at all, saving us from spending time formatting messages (and potentially other expensive work) for lints that don't end up being emitted.
r? @Centril
- Make report_unsafe take decorate function
- Remove span_lint, replacing calls with struct_span_lint, as caller is
now responsible for emitting.
- Remove lookup_and_emit, replacing with just lookup which takes a
decorate function.
- Remove span_lint_note, span_lint_help. These methods aren't easily
made lazy as standalone methods, private, and unused. If this
functionality is needed, to be lazy, they can easily be made into
Fn(&mut DiagnosticBuilder) that are meant to be called _within_ the
decorate function.
- Rename lookup_and_emit_with_diagnostics to lookup_with_diagnostics to
better reflect the fact that it doesn't emit for you.
rustc_codegen_ssa: only "spill" SSA-like values to the stack for debuginfo.
This is an implementation of the idea described in https://github.com/rust-lang/rust/issues/68817#issuecomment-583719182.
In short, instead of debuginfo forcing otherwise-SSA-like MIR locals into `alloca`s, and requiring a `load` for each use (or two, for scalar pairs), the `alloca` is now *only* used for attaching debuginfo with `llvm.dbg.declare`: the `OperandRef` is stored to the `alloca`, but *never loaded* from it.
Outside of `debug_introduce_local`, nothing cares about the debuginfo-only `alloca`, and instead works with `OperandRef` the same as MIR locals without debuginfo before this PR.
This should have some of the benefits of `llvm.dbg.value`, while working today.
cc @nagisa @nikomatsakis
change an instance of span_bug() to struct_span_err() to avoid ICE
After #67148, the `span_bug()` in `parse_ty_tuple_or_parens()` is reachable because `parse_paren_comma_seq()` can return an `Ok()` even in cases where it encounters an error.
This pull request prevents an ICE in such cases by replacing the `span_bug()` with `struct_span_error()`.
Fixes#68890.
self-profile: Support arguments for generic_activities.
This PR adds support for recording arguments of "generic activities". The most notable use case is LLVM module names, which should be very interesting for `crox` profiles. In the future it might be interesting to add more fine-grained events for pre-query passes like macro expansion.
I tried to judiciously de-duplicate existing self-profile events with `extra_verbose_generic_activity`, now that the latter also generates self-profile events.
r? @wesleywiser
Add long error code explanation message for E0637
Reference issue [#61137](https://github.com/rust-lang/rust/issues/61137)
To incorporate a long error description for E0637, I have made the necessary modification to error_codes.rs and added error_codes/E0637.md, and blessed the relevant .stderror files. ~~, however when I build rustc stage 1, I am unable to make `$ rustc --explain E0637` work even though rustc appears to be able to call up the long error explanations for other errors. I wanted to guarantee this would work before moving on the blessing the various ui tests that have been affected. @GuillaumeGomez Do you know the most likely reason(s) why this would be the case?~~
Update: `$ rustc --explain E0637` works now.
Remove problematic specialization from RangeInclusive
Fixes#67194 using the approach [outlined by Mark-Simulacrum](https://github.com/rust-lang/rust/issues/67194#issuecomment-581669549).
> I believe the property we want is that if `PartialEq(&self, &other) == true`, then `self.next() == other.next()`. It is true that this is satisfied by removing the specialization and always doing `is_empty.unwrap_or_default()`; the "wrong" behavior there arises from calling `next()` having an effect on initially empty ranges, as we should be in `is_empty = true` but are not (yet) there. It might be possible to detect that the current state is always empty (i.e., `start > end`) and then not fill in the empty slot. I think this might solve the problem without regressing tests; however, this could have performance implications.
> That approach essentially states that we only use the `is_empty` slot for cases where `start <= end`. That means that `Idx: !Step` and `start > end` would both behave the same, and correctly -- we do not need the boolean if we're not ever going to emit any values from the iterator.
This is implemented here by replacing the `is_empty: Option<bool>` slot with an `exhausted: bool` slot. This flag is
- `false` upon construction,
- `false` when iteration has not yielded an element -- importantly, this means it is always `false` for an iterator empty by construction,
- `false` when iteration has yielded an element and the iterator is not exhausted, and
- only `true` when iteration has been used to exhaust the iterator.
For completeness, this also adds a note to the `Debug` representation to note when the range is exhausted.
Rollup of 6 pull requests
Successful merges:
- #68694 (Reduce the number of `RefCell`s in `InferCtxt`.)
- #68966 (Improve performance of coherence checks)
- #68976 (Make `num::NonZeroX::new` an unstable `const fn`)
- #68992 (Correctly parse `mut a @ b`)
- #69005 (Small graphviz improvements for the new dataflow framework)
- #69006 (parser: Keep current and previous tokens precisely)
Failed merges:
r? @ghost
parser: Keep current and previous tokens precisely
...including their unnormalized forms.
Add more documentation for them.
Hopefully, this will help to eliminate footguns like https://github.com/rust-lang/rust/pull/68728#discussion_r373787486.
I'll try to address the FIXMEs in separate PRs during the next week.
r? @Centril
Make `num::NonZeroX::new` an unstable `const fn`
cc #53718
These require `#[feature(const_if_match)]`, meaning they must remain unstable for the time being.
Reduce the number of `RefCell`s in `InferCtxt`.
`InferCtxt` contains six structures within `RefCell`s. Every time we
create and dispose of (commit or rollback) a snapshot we have to
`borrow_mut` each one of them.
This commit moves the six structures under a single `RefCell`, which
gives significant speed-ups by reducing the number of `borrow_mut`
calls. To avoid runtime errors I had to reduce the lifetimes of dynamic
borrows in a couple of places.
r? @varkor
This was previously a future-compat warning that has since been turned into
hard error, but without actually removing all the code.
Avoids a call to `traits::overlapping_impls`, which is expensive.
This has negligible perf impact, but it does improve the code a bit.
* Only query the specialization graph of any trait once instead of once per
impl
* Loop over impls only once, precomputing impl DefId and TraitRef
Improve reporting errors and suggestions for trait bounds
Fix#66802
- When printing errors for unsized function parameter, properly point at the parameter instead of function's body.
- Improve `consider further restricting this bound` (and related) messages by separating human-oriented hints from the machine-oriented ones.
`InferCtxt` contains six structures within `RefCell`s. Every time we
create and dispose of (commit or rollback) a snapshot we have to
`borrow_mut` each one of them.
This commit moves the six structures under a single `RefCell`, which
gives significant speed-ups by reducing the number of `borrow_mut`
calls. To avoid runtime errors I had to reduce the lifetimes of dynamic
borrows in a couple of places.
Rollup of 5 pull requests
Successful merges:
- #68738 (Derive Clone + Eq for std::string::FromUtf8Error)
- #68742 (implement AsMut<str> for String)
- #68881 (rustc_codegen_llvm: always set AlwaysPreserve on all debuginfo variables)
- #68911 (Speed up the inherent impl overlap check)
- #68913 (Pretty-print generic params and where clauses on associated types)
Failed merges:
r? @ghost
Now the line for each statement will show the diff resulting from the
combination of `before_statement_effect` and `statement_effect`. It's
still possible to observe each in isolation via
`borrowck_graphviz_format = "two_phase"`.
