Introduce `Rvalue::ShallowInitBox`
Polished version of #88700.
Implements MCP rust-lang/compiler-team#460, and should allow #43596 to go forward.
In short, creating an empty box is split from a nullary-op `NullOp::Box` into two steps, first a call to `exchange_malloc`, then a `Rvalue::ShallowInitBox` which transmutes `*mut u8` to a shallow-initialized `Box<T>`. This allows the `exchange_malloc` call to unwind. Details can be found in the MCP.
`NullOp::Box` is not yet removed, purely to make reverting easier in case anything goes wrong as the result of this PR. If revert is needed a reversion of "Use Rvalue::ShallowInitBox for box expression" commit followed by a test bless should be sufficient.
Experiments in #88700 showed a very slight compile-time perf regression due to (supposedly) slightly more time spent in LLVM. We could omit unwind edge generation (in non-`oom=panic` case) in box expression MIR construction to restore perf; but I don't think it's necessary since runtime perf isn't affected and perf difference is rather small.
Be explicit about using Binder::dummy
This is somewhat of a late followup to the binder refactor PR. It removes `ToPredicate` and `ToPolyTraitImpls` that hide the use of `Binder::dummy`. While this does make code a bit more verbose, it allows us be more careful about where we create binders.
Another alternative here might be to add a new trait `ToBinder` or something with a `dummy()` fn. Which could still allow grepping but allows doing something like `trait_ref.dummy()` (but I also wonder if longer-term, it would be better to be even more explicit with a `bind_with_vars(ty::List::empty())` *but* that's not clear yet.
r? ``@nikomatsakis``
Don't lint `suspicious_else_formatting` inside proc-macros
fixes: #7650
I'll add a test for this one soon.
changelog: Don't lint `suspicious_else_formatting` inside proc-macros
Expand box_vec lint to box_collection
fixed#7451
changelog: Expand `box_vec` into [`box_collection`], and have it error on all sorts of boxed collections
Tweak pedantic description for occasional FPs
changelog: none
Okay this is getting a bit picky (you might even say pedantic). I think we need to be careful not use the pedantic category as cover-all for lints with any amount of false positives. Lints with a high degree of FPs should be nursery or restriction IMO. If the pedantic category were to yield, say hypothetically, over 50% FPs, it would just be too annoying to use at all (to be sure, "too picky for me" is not a FP).
CC `@rust-lang/clippy`
Rollup of 12 pull requests
Successful merges:
- #88795 (Print a note if a character literal contains a variation selector)
- #89015 (core::ascii::escape_default: reduce struct size)
- #89078 (Cleanup: Remove needless reference in ParentHirIterator)
- #89086 (Stabilize `Iterator::map_while`)
- #89096 ([bootstrap] Improve the error message when `ninja` is not found to link to installation instructions)
- #89113 (dont `.ensure()` the `thir_abstract_const` query call in `mir_build`)
- #89114 (Fixes a technicality regarding the size of C's `char` type)
- #89115 (⬆️ rust-analyzer)
- #89126 (Fix ICE when `indirect_structural_match` is allowed)
- #89141 (Impl `Error` for `FromSecsError` without foreign type)
- #89142 (Fix match for placeholder region)
- #89147 (add case for checking const refs in check_const_value_eq)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Migrate in-tree crates to 2021
This replaces #89075 (cherry picking some of the commits from there), and closes#88637 and fixes#89074.
It excludes a migration of the library crates for now (see tidy diff) because we have some pending bugs around macro spans to fix there.
I instrumented bootstrap during the migration to make sure all crates moved from 2018 to 2021 had the compatibility warnings applied first.
Originally, the intent was to support cargo fix --edition within bootstrap, but this proved fairly difficult to pull off. We'd need to architect the check functionality to support running cargo check and cargo fix within the same x.py invocation, and only resetting sysroots on check. Further, it was found that cargo fix doesn't behave too well with "not quite workspaces", such as Clippy which has several crates. Bootstrap runs with --manifest-path ... for all the tools, and this makes cargo fix only attempt migration for that crate. We can't use e.g. --workspace due to needing to maintain sysroots for different phases of compilation appropriately.
It is recommended to skip the mass migration of Cargo.toml's to 2021 for review purposes; you can also use `git diff d6cd2c6c877110748296760aefddc21a0ea1d316 -I'^edition = .20...$'` to ignore the edition = 2018/21 lines in the diff.
Retry on some download errors in lintcheck
I'm currently on spotty wifi right now. It is shocking the number of things that break when you lose connection for a few seconds. Some 500 errors should probably also be retried, but this fixes my issue.
changelog: None
This allows the format_args! macro to keep the pre-expansion code out of
the unsafe block without doing gymnastics with nested `match`
expressions. This reduces codegen.
This just applies the suggested fixes from the compatibility warnings,
leaving any that are in practice spurious in. This is primarily intended to
provide a starting point to identify possible fixes to the migrations (e.g., by
avoiding spurious warnings).
A secondary commit cleans these up where they are false positives (as is true in
many of the cases).
Change `while_let_on_iterator` suggestion to use `by_ref()`
It came up in the discussion #7659 that suggesting `iter.by_ref()` is a clearer suggestion than `&mut iter`. I personally think they're equivalent, but if `by_ref()` is clearer to people then that should be the suggestion.
changelog: Change `while_let_on_iterator` suggestion when using `&mut` to use `by_ref()`
New lint: `same_name_method`
changelog: ``[`same_name_method`]``
fix: https://github.com/rust-lang/rust-clippy/issues/7632
It only compares a method in `impl` with another in `impl trait for`
It doesn't lint two methods in two traits.
I'm not sure my approach is the best way. I meet difficulty in other approaches.
Downgrade many_single_char_names to pedantic
As suggested by `@flip1995` in https://github.com/rust-lang/rust-clippy/issues/7666#issuecomment-918993215, by today's standards this lint would be considered `pedantic`.
This is one of the most widely suppressed Clippy lints on crates.io according to https://github.com/dtolnay/noisy-clippy.
In my opinion this lint is just too domain specific for Clippy to have reliable visibility into. Sure there are some cases where the author is just being lazy and could use a kick in the butt, but we're still left with an enormous number of suppressions where single chars are the most appropriate name. For example in the context of colors, a function using `h`, `s`, `l`, `r`, `g`, `b` is 100% sensible and spelling all those out is silly, but it's past the default lint threshold.
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changelog: Moved [`many_single_char_names`] to `pedantic`
Improve accuracy of `mut_key`
Fixes#6745.
Whilst writing the tests for this, I noticed what I believe is a false negative (the code in `@xFrednet's` [comment](https://github.com/rust-lang/rust-clippy/issues/6745#issuecomment-909658267) doesn't trigger the lint). Currently the tests contain a case for this (which is blatantly ignored), but I'm not at all sure how to implement this (since the lint currently behaves completely differently for ADTs). I'm not sure what should be done - on the one hand the extra test cases are misleading, but on the other hand they don't cause much harm and would save effort for anyone fixing that false negative.
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changelog: Improve accuracy of `clippy::mutable_key_type`.
Updating issue templates to avoid @rustbot triggers
This adds a space between the ``@`` and the name *rustbot*. This should now surely fix it. If not, I'm giving up.
@ rustbot label +C-bug
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changelog: none
r? `@camsteffen`
