adjust how closure/generator types are printed
I saw `&[closure@$DIR/issue-20862.rs:2:5]` and I thought it is a slice type, because that's usually what `&[_]` is... it took me a while to realize that this is just a confusing printer and actually there's no slice. Let's use something that cannot be mistaken for a regular type.
give FutureIncompatibilityReason variants more explicit names
Also make the `reason` field mandatory when declaring a lint, to make sure this is a deliberate decision.
tests/ui: Split large_moves.rs and move to lint/large_assignments
To make failing tests easier to debug with `--emit=mir`, etc.
Don't bother with `revisions: attribute option` for both tests though. Seems sufficient to just have that on one of the tests.
`git show -M --find-renames=40%` makes the diff easier to review. Or note that before this change we had one test with 4 errors, now we have 2 tests with 2 errors each.
r? `@oli-obk`
Part of https://github.com/rust-lang/rust/issues/83518
rustc_hir_analysis: add a helper to check function the signature mismatches
This function is now used to check `#[panic_handler]`, `start` lang item, `main`, `#[start]` and intrinsic functions.
The diagnosis produced are now closer to the ones produced by trait/impl method signature mismatch.
This is the first time I do anything with rustc_hir_analysis/rustc_hir_typeck, so comments and suggestions about things I did wrong or that could be improved will be appreciated.
Suggest desugaring to return-position `impl Future` when an `async fn` in trait fails an auto trait bound
First commit allows us to store the span of the `async` keyword in HIR.
Second commit implements a suggestion to desugar an `async fn` to a return-position `impl Future` in trait to slightly improve the `Send` situation being discussed in #115822.
This suggestion is only made when `#![feature(return_type_notation)]` is not enabled -- if it is, we should instead suggest an appropriate where-clause bound.
coverage: Don't bother renumbering expressions on the Rust side
The LLVM API that we use to encode coverage mappings already has its own code for removing unused coverage expressions and renumbering the rest.
This lets us get rid of our own complex renumbering code, making it easier to change our coverage code in other ways.
---
Now that we have tests for coverage mappings (#114843), I've been able to verify that this PR doesn't make the coverage mappings worse, thanks to an explicit simplification step.
Delete obsolete `--disable-per-crate-search` rustdoc flag
This unstable flag is unused by rustdoc since ef96d573bf.
We should avoid landing this until after https://github.com/rust-lang/docs.rs/pull/2225 is deployed to docs.rs.
rename mir::Constant -> mir::ConstOperand, mir::ConstKind -> mir::Const
Also, be more consistent with the `to/eval_bits` methods... we had some that take a type and some that take a size, and then sometimes the one that takes a type is called `bits_for_ty`.
Turns out that `ty::Const`/`mir::ConstKind` carry their type with them, so we don't need to even pass the type to those `eval_bits` functions at all.
However this is not properly consistent yet: in `ty` we have most of the methods on `ty::Const`, but in `mir` we have them on `mir::ConstKind`. And indeed those two types are the ones that correspond to each other. So `mir::ConstantKind` should actually be renamed to `mir::Const`. But what to do with `mir::Constant`? It carries around a span, that's really more like a constant operand that appears as a MIR operand... it's more suited for `syntax.rs` than `consts.rs`, but the bigger question is, which name should it get if we want to align the `mir` and `ty` types? `ConstOperand`? `ConstOp`? `Literal`? It's not a literal but it has a field called `literal` so it would at least be consistently wrong-ish...
``@oli-obk`` any ideas?
Prevent promotion of const fn calls in inline consts
We don't wanna make that mistake we did for statics and consts worse by letting more code use it.
r? ``@RalfJung``
cc https://github.com/rust-lang/rust/issues/76001
Improve invalid UTF-8 lint by finding the expression initializer
This PR introduce a small mechanism to walk up the HIR through bindings, if/else, consts, ... when trying lint on invalid UTF-8.
Fixes https://github.com/rust-lang/rust/issues/115208
After coverage instrumentation and MIR transformations, we can sometimes end up
with coverage expressions that always have a value of zero. Any expression
operand that refers to an always-zero expression can be replaced with a literal
`Operand::Zero`, making the emitted coverage mapping data smaller and simpler.
This simplification step is mostly redundant with the simplifications performed
inline in `expressions_with_regions`, except that it does a slightly more
thorough job in some cases (because it checks for always-zero expressions
*after* other simplifications).
However, adding this simplification step will then let us greatly simplify that
code, without affecting the quality of the emitted coverage maps.
rustc_target/loongarch: Fix passing of transparent unions with only one non-ZST member
This ensures that `MaybeUninit<T>` has the same ABI as `T` when passed through an `extern "C"` function.
Fixes https://github.com/rust-lang/rust/issues/115509
r? `@bjorn3`
coverage: Remove debug code from the instrumentor
The coverage instrumentor has an entire module full of complex code that is only used for debugging.
And as I continue to work on coverage, I keep finding that this debug code is constantly causing more trouble than it's worth. It's deeply entangled with current implementation details, such that making any non-trivial change to the instrumentor usually requires major changes to the debug code. And so far I have personally not found any of this debug code to be *useful*.
In light of that situation, I'd like to try just ripping all of it out. If I spend any more time dealing with coverage debug code, I want it to be because I'm writing new and useful tools, not dutifully maintaining a boat-anchor that quite plausibly isn't being used by anyone at all.
---
r? `@ghost`
`@rustbot` label +A-code-coverage
---
[Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Removing.20debug.20code.20from.20the.20coverage.20instrumentor)
Correctly deny late-bound lifetimes from parent in anon consts and TAITs
Reuse the `AnonConstBoundary` scope (introduced in #108553, renamed in this PR to `LateBoundary`) to deny late-bound vars of *all* kinds (ty/const/lifetime) in anon consts and TAITs.
Side-note, but I would like to consolidate this with the error reporting for RPITs (E0657):
c4f25777a0/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs (L733-L754) but the semantics about what we're allowed to capture there are slightly different, so I'm leaving that untouched.
Fixes#115474
