In match guards, irrefutable prefixes might use the bindings created
by the match pattern. Ideally, we check for this, but we can do the
next best thing and just not lint for irrefutable prefixes in match
guards.
Remove `mir::CastKind::Misc`
As discussed in #97649 `mir::CastKind::Misc` is not clear, this PR addresses that by creating a new enum variant for every valid cast.
r? ````@oli-obk````
Fix unwind drop glue for if-then scopes
cc `@est31`
Fix#102317Fix#99852
This PR fixes the drop glue for unwinding from a panic originated in a drop while breaking out for the else block in an `if-then` scope.
MIR validation does not fail for the synchronous versions of the test program, because `StorageDead` statements are skipped over in the unwinding process. It is only becoming a problem when it is inside a generator where `StorageDead` must be kept around.
Move lint level source explanation to the bottom
So, uhhhhh
r? `@estebank`
## User-facing change
"note: `#[warn(...)]` on by default" and such are moved to the bottom of the diagnostic:
```diff
- = note: `#[warn(unsupported_calling_conventions)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
+ = note: `#[warn(unsupported_calling_conventions)]` on by default
```
Why warning is enabled is the least important thing, so it shouldn't be the first note the user reads, IMO.
## Developer-facing change
`struct_span_lint` and similar methods have a different signature.
Before: `..., impl for<'a> FnOnce(LintDiagnosticBuilder<'a, ()>)`
After: `..., impl Into<DiagnosticMessage>, impl for<'a, 'b> FnOnce(&'b mut DiagnosticBuilder<'a, ()>) -> &'b mut DiagnosticBuilder<'a, ()>`
The reason for this is that `struct_span_lint` needs to edit the diagnostic _after_ `decorate` closure is called. This also makes lint code a little bit nicer in my opinion.
Another option is to use `impl for<'a> FnOnce(LintDiagnosticBuilder<'a, ()>) -> DiagnosticBuilder<'a, ()>` altough I don't _really_ see reasons to do `let lint = lint.build(message)` everywhere.
## Subtle problem
By moving the message outside of the closure (that may not be called if the lint is disabled) `format!(...)` is executed earlier, possibly formatting `Ty` which may call a query that trims paths that crashes the compiler if there were no warnings...
I don't think it's that big of a deal, considering that we move from `format!(...)` to `fluent` (which is lazy by-default) anyway, however this required adding a workaround which is unfortunate.
## P.S.
I'm sorry, I do not how to make this PR smaller/easier to review. Changes to the lint API affect SO MUCH 😢
`Res::SelfTy` currently has two `Option`s. When the second one is `Some`
the first one is never consulted. So we can split it into two variants,
`Res::SelfTyParam` and `Res::SelfTyAlias`, reducing the size of `Res`
from 24 bytes to 12. This then shrinks `hir::Path` and
`hir::PathSegment`, which are the HIR types that take up the most space.
Fix lint scoping for let-else.
The scoping for let-else is inconsistent with HIR nesting. This creates cases, in `ui/let-else/let-else-allow-unused.rs` for instance, where an `allow` lint attribute does not apply to the bindings created by `let-else`.
This PR is an attempt to correct this.
As there is no lint that currently relies on this, the test for this behaviour is https://github.com/rust-lang/rust/pull/101500.
cc `@dingxiangfei2009` as you filed https://github.com/rust-lang/rust/pull/101894
Avoid duplicating StorageLive in let-else
cc `@est31`
Fix#101867Fix#101932#101410 introduced directives to activate storages of bindings in let-else earlier. However, since it is using the machinery of `match` and friends for pattern matching and binding, those storages are activated for the second time. This PR adjusts this behavior and avoid the duplicated activation for let-else statements.
On later stages, the feature is already stable.
Result of running:
rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
Initial implementation of dyn*
This PR adds extremely basic and incomplete support for [dyn*](https://smallcultfollowing.com/babysteps//blog/2022/03/29/dyn-can-we-make-dyn-sized/). The goal is to get something in tree behind a flag to make collaboration easier, and also to make sure the implementation so far is not unreasonable. This PR does quite a few things:
* Introduce `dyn_star` feature flag
* Adds parsing for `dyn* Trait` types
* Defines `dyn* Trait` as a sized type
* Adds support for explicit casts, like `42usize as dyn* Debug`
* Including const evaluation of such casts
* Adds codegen for drop glue so things are cleaned up properly when a `dyn* Trait` object goes out of scope
* Adds codegen for method calls, at least for methods that take `&self`
Quite a bit is still missing, but this gives us a starting point. Note that this is never intended to become stable surface syntax for Rust, but rather `dyn*` is planned to be used as an implementation detail for async functions in dyn traits.
Joint work with `@nikomatsakis` and `@compiler-errors.`
r? `@bjorn3`
Shrink span for bindings with subpatterns.
Bindings with nested patterns (`binding @ pat` syntax) currently point to the full pattern. This PR proposes to shrink the span to stop before the ````@`.``` This makes the diagnostics for move/mutability conflicts clearer, as they not point to the `binding` only, instead of the full pat.
r? ```@estebank```
`Builder::expr_into_pattern` has a single call site. Currently the
`pattern` argument at the call site is always cloned.
This commit changes things so that we instead do a clone within
`expr_into_pattern`, but only if the pattern has the
`PatKind::AscribeUserType` kind, and we only clone the annotation within
the pattern instead of the entire pattern.
`thir::Pat::kind` is a `Box<PatKind>`, which doesn't follow the usual
pattern in AST/HIR/THIR which is that the "kind" enum for a node is
stored inline within the parent struct.
This commit makes the `PatKind` directly inline within the `Pat`. This
requires using `Box<Pat>` in all the types that hold a `Pat.
Ideally, `Pat` would be stored in `Thir` like `Expr` and `Stmt` and
referred to with a `PatId` rather than `Box<Pat>`. But this is hard to
do because lots of `Pat`s get created after the destruction of the `Cx`
that does normal THIR building. But this does get us a step closer to
`PatId`, because all the `Box<Pat>` occurrences would be replaced with
`PatId` if `PatId` ever happened.
At 128 bytes, `Pat` is large. Subsequent commits will shrink it.
This PR will fix some typos detected by [typos].
I only picked the ones I was sure were spelling errors to fix, mostly in
the comments.
[typos]: https://github.com/crate-ci/typos
Replace `Body::basic_blocks()` with field access
Since the refactoring in #98930, it is possible to borrow the basic blocks
independently from other parts of MIR by accessing the `basic_blocks` field
directly.
Replace unnecessary `Body::basic_blocks()` method with a direct field access,
which has an additional benefit of borrowing the basic blocks only.
let-else: break out to one scope higher for let-else
```@est31``` This PR follows up with #99518 which is to break out to the last remainder scope. It breaks to the out-most `region_scope` of the block if the first statement is a `let-else`.
Expand potential inner `Or` pattern for THIR
Code assumed there wouldn't be a deeper `Or` pattern inside expanded `PatStack` this fixes it by looking for the `Or` pattern inside expanded `PatStack`.
A more ideal solution would be recursively doing this but I haven't found a good way to do that.
_fixes #97898_
never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn)
Judging from https://github.com/rust-lang/rust/issues/71668#issuecomment-1200317370 the consensus nowadays seems to be that we should never consider an unsafe block unused if it was required with `deny(unsafe_op_in_unsafe_fn)`, no matter whether that lint is actually enabled or not. So let's adjust rustc accordingly.
The first commit does the change, the 2nd does some cleanup.
Determine match_has_guard from candidates instead of looking up thir table again
Currently looking through mir build of matches because of interest in deref patterns. Finding some micro-optimizable things.
Enable unused_parens for match arms
Fixes: https://github.com/rust-lang/rust/issues/92751
Currently I can't get the `stderr` to work with `./x.py test`, but this should fix the issue. Help would be appreciated!
Some `is_useful` cleanups
#98582 was reverted because it was a perf regression.
https://github.com/rust-lang/rust/pull/99806 reintroduces the changes, but this PR picks individual ones that have no regressions.
Let-else: break out scopes when a let-else pattern fails to match
This PR will commit to a new behavior so that values from initializer expressions are dropped earlier when a let-else pattern fails to match.
Fix#98672.
Close#93951.
cc `@camsteffen` `@est31`
Deeply deny fn and raw ptrs in const generics
I think this is right -- just because we wrap a fn ptr in a wrapper type does not mean we should allow it in a const parameter.
We now reject both of these in the same way:
```
#![feature(adt_const_params)]
#[derive(Eq, PartialEq)]
struct Wrapper();
fn foo<const W: Wrapper>() {}
fn foo2<const F: fn()>() {}
```
This does regress one test (`src/test/ui/consts/refs_check_const_eq-issue-88384.stderr`), but I'm not sure it should've passed in the first place.
cc: ``@b-naber`` who introduced that test^
fixes#99641
Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
Implement `SourceMap::is_span_accessible`
This patch adds `SourceMap::is_span_accessible` and replaces `span_to_snippet(span).is_ok()` and `span_to_snippet(span).is_err()` with it. This removes a `&str` to `String` conversion.
There are several indications that we should not ZST as a ScalarInt:
- We had two ways to have ZST valtrees, either an empty `Branch` or a `Leaf` with a ZST in it.
`ValTree::zst()` used the former, but the latter could possibly arise as well.
- Likewise, the interpreter had `Immediate::Uninit` and `Immediate::Scalar(Scalar::ZST)`.
- LLVM codegen already had to special-case ZST ScalarInt.
So instead add new ZST variants to those types that did not have other variants
which could be used for this purpose.
This makes it possible to mutably borrow different fields of the MIR
body without resorting to methods like `basic_blocks_local_decls_mut_and_var_debug_info`.
To preserve validity of control flow graph caches in the presence of
modifications, a new struct `BasicBlocks` wraps together basic blocks
and control flow graph caches.
The `BasicBlocks` dereferences to `IndexVec<BasicBlock, BasicBlockData>`.
On the other hand a mutable access requires explicit `as_mut()` call.
lints: mostly translatable diagnostics
As lints are created slightly differently than other diagnostics, intended to try make them translatable first and then look into the applicability of diagnostic structs but ended up just making most of the diagnostics in the crate translatable (which will still be useful if I do make a lot of them structs later anyway).
r? ``@compiler-errors``
Change enum->int casts to not go through MIR casts.
follow-up to https://github.com/rust-lang/rust/pull/96814
this simplifies all backends and even gives LLVM more information about the return value of `Rvalue::Discriminant`, enabling optimizations in more cases.
Rewrite dead-code pass to avoid fetching HIR.
This allows to get a more uniform handling of spans, and to simplify the grouping of diagnostics for variants and fields.
Accept `DiagnosticMessage` in `LintDiagnosticBuilder::build` so that
lints can be built with translatable diagnostic messages.
Signed-off-by: David Wood <david.wood@huawei.com>
Avoid some `&str` to `String` conversions with `MultiSpan::push_span_label`
This patch removes some`&str` to `String` conversions with `MultiSpan::push_span_label`.
Don't omit comma when suggesting wildcard arm after macro expr
* Also adds `Span::eq_ctxt` to consolidate the various usages of `span.ctxt() == other.ctxt()`
* Also fixes an unhygenic usage of spans which caused the suggestion to render weirdly when we had one arm match in a macro
* Also always suggests a comma (i.e. even after a block) if we're rendering a wildcard arm in a single-line match (looks prettier 🌹)
Fixes#94866
Fix `SourceScope` for `if let` bindings.
Fixes#97799.
I'm not sure how to test this properly, is there any way to observe the difference in behavior apart from `ui` tests? I'm worried that they would be overlooked in the case of a regression.
This commit removes the `a == b` early return, which isn't useful in
practice, and replaces it with one that helps matches with many ranges,
including char ranges.
The code is clearer and simpler without it. Note that the `a == b` early
return at the top of the function means the `a == b` test at the end of
the function could never succeed.
It's never executed when running the entire test suite. I think it's
because of the early return at the top of the function if `a.ty() != ty`
succeeds.
This is a performance win for `unicode-normalization`.
The commit also removes the closure, which isn't necessary. And
reformulates the comparison into a form I find easier to read.
Make `ExprKind::Closure` a struct variant.
Simple refactor since we both need it to introduce additional fields in `ExprKind::Closure`.
r? ``@Aaron1011``
