Suggestion for type mismatch when we need a u8 but the programmer wrote a char literal
Today Rust just points out that we have a char and we need a u8, but if I wrote 'A' then I could fix this by just writing b'A' instead. This code should detect the case where we're about to report a type mismatch of this kind, and the programmer wrote a char literal, and the char they wrote is ASCII, so therefore just prefixing b to make a byte literal will do what they meant.
I have definitely written this mistake more than once, it's not difficult to figure out what to do, but the compiler might as well tell us anyway.
I provided a test with two simple examples where the suggestion is appropriate, and one where it is not because the char literal is not ASCII, showing that the suggestion is only triggered in the former cases.
I have contributed only a small typo doc fix before, so this is my first substantive rustc change.
Rollup of 8 pull requests
Successful merges:
- #105526 (libcore: make result of iter::from_generator Clone)
- #106563 (Fix `unused_braces` on generic const expr macro call)
- #106661 (Stop probing for statx unless necessary)
- #106820 (Deprioritize fulfillment errors that come from expansions.)
- #106828 (rustdoc: remove `docblock` class from notable trait popover)
- #106849 (Allocate one less vec while parsing arrays)
- #106855 (rustdoc: few small cleanups)
- #106860 (Remove various double spaces in the libraries.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove various double spaces in the libraries.
I was just pretty bothered by this when reading the source for a function, and was suggested to check if this happened elsewhere.
rustdoc: remove `docblock` class from notable trait popover
This commit builds on b72de9be74, which removes the `docblock` class from the All Items page, and 9457380ac9, which removes the `docblock` class from the item decl.
Fixes#92974
Stop probing for statx unless necessary
As is the current toy program:
fn main() -> std::io::Result<()> {
use std::fs;
let metadata = fs::metadata("foo.txt")?;
assert!(!metadata.is_dir());
Ok(())
}
... observed under strace will issue:
[snip]
statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address) statx(AT_FDCWD, "foo.txt", AT_STATX_SYNC_AS_STAT, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=0, ...}) = 0
While statx is not necessarily always present, checking for it can be delayed to the first error condition. Said condition may very well never happen, in which case the check got avoided altogether.
Note this is still suboptimal as there still will be programs issuing it, but bulk of the problem is removed.
Tested by forbidding the syscall for the binary and observing it correctly falls back to newfstatat.
While here tidy up the commentary, in particular by denoting some problems with the current approach.
Switch to `EarlyBinder` for `const_param_default` and `impl_trait_ref` queries
Part of the work to close#105779 and implement https://github.com/rust-lang/types-team/issues/78.
Several queries `X` have a `bound_X` variant that wraps the output in `EarlyBinder`. This PR adds `EarlyBinder` to the return type of `const_param_default` and `impl_trait_ref`, and removes their `bound_X` variants.
r? `@lcnr`
Rollup of 10 pull requests
Successful merges:
- #106046 (Fix mir-opt tests for big-endian platforms)
- #106470 (tidy: Don't include wasm32 in compiler dependency check)
- #106566 (Emit a single error for contiguous sequences of unknown tokens)
- #106644 (Update the wasi-libc used for the wasm32-wasi target)
- #106665 (Add note when `FnPtr` vs. `FnDef` impl trait)
- #106752 (Emit a hint for bad call return types due to generic arguments)
- #106788 (Tweak E0599 and elaborate_predicates)
- #106831 (Use GitHub yaml templates for ICE, Docs and Diagnostics tickets)
- #106846 (Improve some comments and names in parser)
- #106848 (Fix wrong path in triage bot autolabel for wg-trait-solver-refactor)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Use GitHub yaml templates for ICE, Docs and Diagnostics tickets
The GitHub yaml templates allow us to define HTML forms with validation for issue templates, instead of the current markdown based templates which only let us introduce text into the user editable text area. The form lets us make some fields mandatory, as well as add text that won't pollute the user's text and titles that won't be interfered with by enterprising users.
Emit a hint for bad call return types due to generic arguments
When the return type of a function call depends on the type of an argument, e.g.
```
fn foo<T>(x: T) -> T {
x
}
```
and the expected type is set due to either an explicitly typed binding, or because the call to the function is in a tail position without semicolon, the current error implies that the argument in the call has the wrong type.
This new hint highlights that the expected type doesn't match the returned type, which matches the argument type, and that that's why we're flagging the argument type.
Fixes#43608.
Add note when `FnPtr` vs. `FnDef` impl trait
I encountered an instance where an `FnPtr` implemented a trait, but I was passing an `FnDef`. I was confused for an hour and to examine the source code of the trait's crate's tests in order to understand how to cast it properly (it didn't help that it was behind a reference). To the end user, it might not be immediately obvious that they are different and how to convert from an `FnDef` to an `FnPtr`, but it is necessary to cast to the generic function in order to compile. It is thus useful to suggest `as` in the help note, (even if the `Fn` output implements the trait).
Update the wasi-libc used for the wasm32-wasi target
This commit updates the wasi-libc revision used to build with the wasm32-wasi target. This notably pulls in WebAssembly/wasi-libc#377 which is needed to fix a use case I've been working on recently. This should be a relatively small update hopefully and is not expected to have any user impact.
Emit a single error for contiguous sequences of unknown tokens
Closes#106101
On encountering a sequence of identical source characters which are unknown tokens, note the amount of subsequent characters and advance past them silently. The old behavior was to emit an error and 'help' note for every single one.
`@rustbot` label +A-diagnostics +A-parser
tidy: Don't include wasm32 in compiler dependency check
This changes the tidy compiler dependency check so that it does not include wasm32-unknown-unknown dependencies in the PERMITTED_RUSTC_DEPENDENCIES. This just helps keep the list cleaner under the assumption that the compiler will never work on wasm32-unknown-unknown.
This also fixes a bug in the check to verify there are no unused dependencies in the PERMITTED_RUSTC_DEPENDENCIES. Previously the check was verifying that the dependency was used *anywhere* in the workspace, when it should have been checking if it was used for the compiler.
There's also just a little general cleanup here. For example, the old `normal_deps_of_r` function was changed a while ago to return *all* dependencies, but the function name and description wasn't updated to remove `normal_`.
Fix mir-opt tests for big-endian platforms
The test cases src/test/mir-opt/building/custom/consts.rs and src/test/mir-opt/const_prop/mutable_variable_no_prop.rs are currently failing on big-endian platforms as the binary encoding of some constants is hard-coded in the MIR test files. Fix this by choosing constant values that have the same encoding on big- and little-endian platforms.
The test case src/test/mir-opt/issues/issue_75439.rs is failing as well, but since the purpose of the test is to validate handling of big-endian integer encodings on a little-endian platform, it does not make much sense to run it on big-endian platforms in the first place - we can just ignore it there.
Fixed part of https://github.com/rust-lang/rust/issues/105383.
I encountered an instance where an `FnPtr` implemented a trait, but I was passing an `FnDef`. To
the end user, there is really no way to differentiate each of them, but it is necessary to cast
to the generic function in order to compile. It is thus useful to suggest `as` in the help note,
(even if the Fn output implements the trait).
Fix aarch64-unknown-linux-gnu_ilp32 target
This was broken because the synthetic object files produced by rustc were for 64-bit AArch64, which caused link failures when combined with 32-bit ILP32 object files.
This PR updates the object crate to 0.30.1 which adds support for generating ILP32 AArch64 object files.
Update mdbook
This updates mdbook from 0.4.21 to 0.4.25. The list of changes is [here](https://github.com/rust-lang/mdBook/blob/master/CHANGELOG.md#mdbook-0425). The only user-visible changes are some changes around the theme picker, and change to the copy-to-clipboard ignoring hidden lines.
Internally there were some dependency updates and small fixes.
This also updates `clap` from 4.0.15 to 4.0.32 whose changelog is [here](https://github.com/clap-rs/clap/blob/master/CHANGELOG.md#4032---2022-12-22). This impacts tools like cargo. I don't see anything particularly noteworthy there, though there are some small user-visible changes.
Unfortunately this required adding a hack for building `rustix` with a bootstrap tool. The comment explains why. I am unable to think of some other workaround (or even a cleaner way to set the rustflag). Ideas are welcome if you can think of alternatives. I'm struggling to even think of a long-term solution, other than asking projects not to do auto-nightly feature detection.
One medium-term solution is to avoid the clap dependency for the mdbook library (which is how rustix gets pulled in). That is one of my goals for the 0.5 release of mdbook, but that probably won't happen until later this year. It would also require dropping clap from `rustbook` and using some other means to parse arguments (there's only two options, so it can probably be done manually).
rustdoc: remove unnecessary DOM class `h1.fqn`
It's misleading. The main heading sometimes isn't an fully qualified name at all.
It's also redundant. It's always a child of `div.main-heading`, so just use that.
Update `rental` hack to work with remapped paths.
This PR simply switches to an already-existing helper instead of hard-coding a specific enum variant. The new revision of the test fails without the other changes in this PR.
Context: I'm exploring running UI tests with remapped paths by default in #105924 and the rental test was one of the ones that failed.
This may also be useful in the context of https://github.com/rust-lang/rfcs/pull/3127 ("New rustc and Cargo options to allow path sanitisation by default").
Matthias Krüger
