coverage: Replace the old span refiner with a single function
As more and more of the span refiner's functionality has been pulled out into separate early passes, it has finally reached the point where we can remove the rest of the old `SpansRefiner` code, and replace it with a single modestly-sized function.
~~There should be no change to the resulting coverage mappings, as demonstrated by the lack of changes to test output.~~
There is *almost* no change to the resulting coverage mappings. There are some minor changes to `loop` that on inspection appear to be neutral in terms of accuracy, with the old behaviour being a slightly-horrifying implementation detail of the old code, so I think they're acceptable.
Previous work in this direction includes:
- #125921
- #121019
- #119208
Provide correct parent for nested anon const
Fixes#126147
99% of this PR is just comments explaining what the issue is.
`tcx.parent(` and `hir().get_parent_item(` give different results as the hir owner for all the hir of anon consts is the enclosing function. I didn't attempt to change that as being a hir owner requires a `DefId` and long term we want to stop creating anon consts' `DefId`s before hir ty lowering.
So i just opted to change `generics_of` to use `tcx.parent` to get the parent for `AnonConst`'s. I'm not entirely sure about this being what we want, it does seem weird that we have two ways of getting the parent of an `AnonConst` and they both give different results.
Alternatively we could just go ahead and make `const_evaluatable_unchecked` a hard error and stop providing generics to repeat exprs. Then this isn't an issue. (The FCW has been around for almost 4 years now)
r? ````@compiler-errors````
Remove `DebugWithInfcx` machinery
This PR removes `DebugWithInfcx` after having a lot of second thoughts about it due to recent type system uplifting work. We could add it back later if we want, but I don't think the amount of boilerplate in the complier and the existence of (kindof) hacks like `NoInfcx` currently justify the existence of `DebugWithInfcx`, especially since it's not even being used anywhere in the compiler currently.
The motivation for `DebugWithInfcx` is that we want to be able to print infcx-aware information, such as universe information[^1] (though if there are other usages that I'm overlooking, please let me know). I think there are probably more tailored solutions that can specifically be employed in places where this infcx-aware printing is necessary. For example, one way of achieving this is by implementing a custom `FmtPrinter` which overloads `ty_infer_name` (perhaps also extending it to have overrideable stubs for printing placeholders too) to print the `?u.i` name for an infer var. This will necessitate uplifting `Print` from `rustc_middle::ty::print`, but this seems a bit more extensible and reusable than `DebugWithInfcx`.
One of the problems w/ `DebugWithInfcx` is its opt-in-ness. Even if a compiler dev adds a new `debug!(ty)` in a context where there is an `infcx` we can access, they have to *opt-in* to using `DebugWithInfcx` with something like `debug!(infcx.with(ty))`. This feels to me like it risks a lot of boilerplate, and very easy to just forget adding it at all, especially in cases like `#[instrument]`.
A second problem is the `NoInfcx` type itself. It's necessary to have this dummy infcx implementation since we often want to print types outside of the scope of a valid `Infcx`. Right now, `NoInfcx` is only *partially* a valid implementation of `InferCtxtLike`, except for the methods that we specifically need for `DebugWithInfcx`. As I work on uplifting the trait solver, I actually want to add a lot more methods to `InferCtxtLike` and having to add `unreachable!("this should never be called")` stubs for uplifted methods like `next_ty_var` is quite annoying.
In reality, I actually only *really* care about the second problem -- we could, perhaps, instead just try to get rid of `NoInfcx` and just just duplicate `Debug` and `DebugWithInfcx` for most types. If we're okay with duplicating all these implementations (though most of them would just be trivial `#[derive(Debug, DebugWithInfcx)]`), I'd be okay with that too 🤔
r? `@BoxyUwU` `@lcnr` would like to know your thoughts -- happy to discuss this further, mainly trying to bring this problem up
[^1]: Which in my experience is only really necessary when we're debugging things like generalizer bugs.
As more and more of the span refiner's functionality has been pulled out into
separate early passes, it has finally reached the point where we can remove the
rest of the old `SpansRefiner` code, and replace it with a single
modestly-sized function.
Rollup of 16 pull requests
Successful merges:
- #123374 (DOC: Add FFI example for slice::from_raw_parts())
- #124514 (Recommend to never display zero disambiguators when demangling v0 symbols)
- #125978 (Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking)
- #125980 (Nvptx remove direct passmode)
- #126187 (For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.)
- #126210 (docs(core): make more const_ptr doctests assert instead of printing)
- #126249 (Simplify `[T; N]::try_map` signature)
- #126256 (Add {{target}} substitution to compiletest)
- #126263 (Make issue-122805.rs big endian compatible)
- #126281 (set_env: State the conclusion upfront)
- #126286 (Make `storage-live.rs` robust against rustc internal changes.)
- #126287 (Update a cranelift patch file for formatting changes.)
- #126301 (Use `tidy` to sort crate attributes for all compiler crates.)
- #126305 (Make PathBuf less Ok with adding UTF-16 then `into_string`)
- #126310 (Migrate run make prefer rlib)
- #126314 (fix RELEASES: we do not support upcasting to auto traits)
r? `@ghost`
`@rustbot` modify labels: rollup
Make `storage-live.rs` robust against rustc internal changes.
Currently it can be made to fail by rearranging code within `compiler/rustc_mir_transform/src/lint.rs`.
This is a precursor to #125443.
r? ```@lqd```
Make issue-122805.rs big endian compatible
Instead of not generating the function at all on big endian (which makes the CHECK lines fail), instead use to_le() on big endian, so that we essentially perform a bswap for both endiannesses.
For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.
Adding suggestions for following function in E0277.
```rust
fn main() {
let mut _file = File::create("foo.txt")?;
}
```
to
```rust
fn main() -> Result<(), Box<dyn std::error::Error>> {
let mut _file = File::create("foo.txt")?;
return Ok(());
}
```
According to the issue #125997, only the code examples in the issue are targeted, but the issue covers a wider range of situations.
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Nvptx remove direct passmode
This PR does what should have been done in #117671. That is fully avoid using the `PassMode::Direct` for `extern "C" fn` for `nvptx64-nvidia-cuda` and enable the compatibility test. `@RalfJung` [pointed me in the right direction](https://github.com/rust-lang/rust/issues/117480#issuecomment-2137712501) for solving this issue.
There are still some ABI bugs after this PR is merged. These ABI tests are created based on what is actually correct, and since they continue passing with even more of them enabled things are improving. I don't have the time to tackle all the remaining issues right now, but I think getting these improvements merged is very valuable in themselves and plan to tackle more of them long term.
This also doesn't remove the use of `PassMode::Direct` for `extern "ptx-kernel" fn`. This was also not trivial to make work. And since the ABI is hidden behind an unstable feature it's less urgent.
I don't know if it's correct to request `@RalfJung` as a reviewer (due to team structures), but he helped me a lot to figure out this stuff. If that's not appropriate then `@davidtwco` would be a good candidate since he know about this topic from #117671
r? `@RalfJung`
Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking
Use `probe_assoc_item` (for hygienically probing an assoc item and checking if it's accessible wrt. visibility and stability) for assoc item constraints, too, not just for assoc type paths and make the privacy error translatable.
Edition 2024: Make `!` fall back to `!`
This PR changes never type fallback to be `!` (the never type itself) in the next, 2024, edition.
This makes the never type's behavior more intuitive (in 2024 edition) and is the first step of the path to stabilize it.
r? `@compiler-errors`
Rollup of 6 pull requests
Successful merges:
- #115974 (Split core's PanicInfo and std's PanicInfo)
- #125659 (Remove usage of `isize` in example)
- #125669 (CI: Update riscv64gc-linux job to Ubuntu 22.04, rename to riscv64gc-gnu)
- #125684 (Account for existing bindings when suggesting `pin!()`)
- #126055 (Expand list of trait implementers in E0277 when calling rustc with --verbose)
- #126174 (Migrate `tests/run-make/prefer-dylib` to `rmake.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
Account for existing bindings when suggesting `pin!()`
When we encounter a situation where we'd suggest `pin!()`, we now account for that expression existing as part of an assignment and provide an appropriate suggestion:
```
error[E0599]: no method named `poll` found for type parameter `F` in the current scope
--> $DIR/pin-needed-to-poll-3.rs:19:28
|
LL | impl<F> Future for FutureWrapper<F>
| - method `poll` not found for this type parameter
...
LL | let res = self.fut.poll(cx);
| ^^^^ method not found in `F`
|
help: consider pinning the expression
|
LL ~ let mut pinned = std::pin::pin!(self.fut);
LL ~ let res = pinned.as_mut().poll(cx);
|
```
Fix#125661.
Split core's PanicInfo and std's PanicInfo
`PanicInfo` is used in two ways:
1. As argument to the `#[panic_handler]` in `no_std` context.
2. As argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in `std` context.
In situation 1, the `PanicInfo` always has a *message* (of type `fmt::Arguments`), but never a *payload* (of type `&dyn Any`).
In situation 2, the `PanicInfo` always has a *payload* (which is often a `String`), but not always a *message*.
Having these as the same type is annoying. It means we can't add `.message()` to the first one without also finding a way to properly support it on the second one. (Which is what https://github.com/rust-lang/rust/issues/66745 is blocked on.)
It also means that, because the implementation is in `core`, the implementation cannot make use of the `String` type (which doesn't exist in `core`): 0692db1a90/library/core/src/panic/panic_info.rs (L171-L172)
This also means that we cannot easily add a useful method like `PanicInfo::payload_as_str() -> Option<&str>` that works for both `&'static str` and `String` payloads.
I don't see any good reasons for these to be the same type, other than historical reasons.
---
This PR is makes 1 and 2 separate types. To try to avoid breaking existing code and reduce churn, the first one is still named `core::panic::PanicInfo`, and `std::panic::PanicInfo` is a new (deprecated) alias to `PanicHookInfo`. The crater run showed this as a viable option, since people write `core::` when defining a `#[panic_handler]` (because they're in `no_std`) and `std::` when writing a panic hook (since then they're definitely using `std`). On top of that, many definitions of a panic hook don't specify a type at all: they are written as a closure with an inferred argument type.
(Based on some thoughts I was having here: https://github.com/rust-lang/rust/pull/115561#issuecomment-1725830032)
---
For the release notes:
> We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0.
>
> `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*.
>
> The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`.
Print `token::Interpolated` with token stream pretty printing.
This is a step towards removing `token::Interpolated` (#124141). It unavoidably changes the output of the `stringify!` macro, generally for the better.
r? `@petrochenkov`
run-make-support: add wrapper for `fs` operations
Suggested by #125728.
The point of this wrapper is to stop silent fails caused by forgetting to `unwrap` `fs` functions. However, functions like `fs::read` which return something and get stored in a variable should cause a failure on their own if they are not unwrapped (as the `Result` will be stored in the variable, and something will be done on that `Result` that should have been done to its contents). Is it still pertinent to wrap `fs::read_to_string`, `fs::metadata` and so on?
Closes: https://github.com/rust-lang/rust/issues/125728
try-job: x86_64-msvc
try-job: i686-mingw
Instead of not generating the function at all on big endian (which
makes the CHECK lines fail), instead use to_le() on big endian,
so that we essentially perform a bswap for both endiannesses.
Rollup of 5 pull requests
Successful merges:
- #126186 (Migrate `run-make/multiple-emits` to `rmake.rs`)
- #126236 (Delegation: fix ICE on recursive delegation)
- #126254 (Remove ignore-cross-compile directive from ui/macros/proc_macro)
- #126258 (Do not define opaque types when selecting impls)
- #126265 (interpret: ensure we check bool/char for validity when they are used in a cast)
r? `@ghost`
`@rustbot` modify labels: rollup
interpret: ensure we check bool/char for validity when they are used in a cast
In general, `Scalar::to_bits` is a bit dangerous as it bypasses all type information. We should usually prefer matching on the type and acting according to that. So I also refactored `unary_op` handling of integers to do that. The remaining `to_bits` uses are operations that just fundamentally don't care about the sign (and only work on integers).
invalid_char_cast.rs is the key new test, the others already passed before this PR.
r? `@oli-obk`
Remove ignore-cross-compile directive from ui/macros/proc_macro
All the other proc-macro tests don't have this, presumably this was forgotten when the restriction got lifted as it does test just fine
r? `@pietroalbini`
run-make: arm command wrappers with drop bombs
This PR is one in a series of cleanups to run-make tests and the run-make-support library.
### Summary
It's easy to forget to actually executed constructed command wrappers, e.g. `rustc().input("foo.rs")` but forget the `run()`, so to help catch these mistakes, we arm command wrappers with drop bombs on construction to force them to be executed by test code.
This PR also removes the `Deref`/`DerefMut` impl for our custom `Command` which derefs to `std::process::Command` because it can cause issues when trying to use a custom command:
```rs
htmldocck().arg().run()
```
fails to compile because the `arg()` is resolved to `std::process::Command::arg`, which returns `&mut std::process::Command` that doesn't have a `run()` command.
This PR also:
- Removes `env_var` on the `impl_common_helper` macro that was wrongly named and is a footgun (no users).
- Bumps the run-make-support library to version `0.1.0`.
- Adds a changelog to the support library.
### Details
Especially for command wrappers like `Rustc`, it's very easy to build up
a command invocation but forget to actually execute it, e.g. by using
`run()`. This commit adds "drop bombs" to command wrappers, which are
armed on command wrapper construction, and only defused if the command
is executed (through `run`, `run_fail`).
If the test writer forgets to execute the command, the drop bomb will
"explode" and panic with an error message. This is so that tests don't
silently pass with constructed-but-not-executed command wrappers.
This PR is best reviewed commit-by-commit.
try-job: x86_64-msvc
Rollup of 5 pull requests
Successful merges:
- #125913 (Spruce up the diagnostics of some early lints)
- #126234 (Delegation: fix ICE on late diagnostics)
- #126253 (Simplify assert matchers in `run-make-support`)
- #126257 (Rename `needs-matching-clang` to `needs-force-clang-based-tests`)
- #126259 (reachable computation: clarify comments around consts)
r? `@ghost`
`@rustbot` modify labels: rollup
Rename `needs-matching-clang` to `needs-force-clang-based-tests`
This header is much more restrictive than its old name would suggest. As a result, most of the tests that use it don't actually run in any CI jobs.
Mitigation for #126180, though at some point we still need to go back fix the affected tests to actually run.
Spruce up the diagnostics of some early lints
Implement the various "*(note to myself) in a follow-up PR we should turn parts of this message into a subdiagnostic (help msg or even struct sugg)*" drive-by comments I left in #124417 during my review.
For context, before #124417, only a few early lints touched/decorated/customized their diagnostic because the former API made it a bit awkward. Likely because of that, things that should've been subdiagnostics were just crammed into the primary message. This PR rectifies this.
