dont randomly use `_` to print out const generic arguments
const generics seem to get printed out as `_` for no reason a lot of the time, as someone who spends a lot of time with const generics this has gotten ✨ very annoying ✨. Latest example would be #106423 where the ICE messaged formatted a `ty::Const` containing no infer vars, as `_`.
For some reason printing of the const argument on arrays was custom instead of using the existing logic for printing `ty::Const`. Additionally the existing logic for printing `ty::Const` would print out `_` for anon consts that are in a separate crate leading to weird diagnostics (see second commit). There ought to be less cases of consts randomly getting printed as `_` hiding valuable info now.
Add 'static lifetime suggestion when GAT implied 'static requirement from HRTB
Fix for issue #105507
The problem:
When generic associated types (GATs) are from higher-ranked trait bounds (HRTB), they are implied 'static requirement (see
[Implied 'static requirement from higher-ranked trait bounds](https://blog.rust-lang.org/2022/10/28/gats-stabilization.html#implied-static-requirement-from-higher-ranked-trait-bounds) for more details). If the user did not explicitly specify the `'static` lifetime when using the GAT, the current error message will only point out the type `does not live long enough` where the type is used, but not where the GAT is specified and how to fix the problem.
The solution:
Add notes at the span where the problematic GATs are specified and suggestions of how to fix the problem by adding `'static` lifetime at the right spans.
Rollup of 7 pull requests
Successful merges:
- #104505 (Remove double spaces after dots in comments)
- #106784 (prevent E0512 from emitting [type error] by checking the references_error)
- #106834 (new trait solver: only consider goal changed if response is not identity)
- #106889 (Mention the lack of `windows_mut` in `windows`)
- #106963 (Use `scope_expr_id` from `ProbeCtxt`)
- #106970 (Switch to `EarlyBinder` for `item_bounds` query)
- #106980 (Hide `_use_mk_alias_ty_instead` in `<AliasTy as Debug>::fmt`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Put `noundef` on all scalars that don't allow uninit
Previously, it was only put on scalars with range validity invariants like bool, was uninit was obviously invalid for those.
Since then, we have normatively declared all uninit primitives to be undefined behavior and can therefore put `noundef` on them.
The remaining concern was the `mem::uninitialized` function, which cause quite a lot of UB in the older parts of the ecosystem. After #99182, this function now doesn't return uninit values anymore, making users of it safe from this change.
The only real sources of UB where people could encounter uninit primitives are `MaybeUninit::uninit().assume_init()`, which has always be clear in the docs about being UB and from heap allocations (like reading from the spare capacity of a vec). This is hopefully rare enough to not break anything.
cc `@nagisa` `@scottmcm` `@nikic`
Constify `TypeId` ordering impls
Tracking issue: #101871
Adding const ordering to `TypeId` allows rtti crates to optimize some casting scenarios (without transmuting to `u64`). This would also prevent these crates from breaking if the underlying type is changed from `u64` to something different.
Feature gate: `#![feature(const_cmp_type_id)]`
fix: don't emit `E0711` if `staged_api` not enabled
Fixes#106589
Simple fix, added UI test.
As an aside, it seems a lot of features are susceptible to this, `E0711` stands out to me because it's perma-unstable and we are effectively exposing an implementation detail.
Previously, it was only put on scalars with range validity invariants
like bool, was uninit was obviously invalid for those.
Since then, we have normatively declared all uninit primitives to be
undefined behavior and can therefore put `noundef` on them.
The remaining concern was the `mem::uninitialized` function, which cause
quite a lot of UB in the older parts of the ecosystem. This function now
doesn't return uninit values anymore, making users of it safe from this
change.
The only real sources of UB where people could encounter uninit
primitives are `MaybeUninit::uninit().assume_init()`, which has always
be clear in the docs about being UB and from heap allocations (like
reading from the spare capacity of a vec. This is hopefully rare enough
to not break anything.
rustdoc: remove redundant item kind class from `.item-decl > pre`
This class originated in the very first commit of `rustdoc_ng`, and was used to add a color border around the item decl based on its kind.
4fd061c426/src/rustdoc_ng/html/static/main.css (L102-L106)
The item decl no longer has a border, and there aren't any kind-specific styles in modern rustdoc's rendering of this UI item.
Most of this PR is updating test cases so that they use `item-decl` to find the `<pre>` tag instead of relying on the fact that the class name had `rust {kind}` in it while other `<pre>` tags only had class `rust`.
make error emitted on `impl &Trait` nicer
Fixes#106694
Turned out to be simpler than I thought, also added UI test.
Before: ([playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=9bda53271ef3a8886793cf427b8cea91))
```text
error: expected one of `:`, ``@`,` or `|`, found `)`
--> src/main.rs:2:22
|
2 | fn foo(_: impl &Trait) {}
| ^ expected one of `:`, ``@`,` or `|`
|
= note: anonymous parameters are removed in the 2018 edition (see RFC 1685)
help: if this is a parameter name, give it a type
|
2 | fn foo(_: impl Trait: &TypeName) {}
| ~~~~~~~~~~~~~~~~
help: if this is a type, explicitly ignore the parameter name
|
2 | fn foo(_: impl _: &Trait) {}
| ++
error: expected one of `!`, `(`, `)`, `,`, `?`, `for`, `~`, lifetime, or path, found `&`
--> src/main.rs:2:16
|
2 | fn foo(_: impl &Trait) {}
| -^ expected one of 9 possible tokens
| |
| help: missing `,`
error: expected one of `!`, `(`, `,`, `=`, `>`, `?`, `for`, `~`, lifetime, or path, found `&`
--> src/main.rs:3:11
|
3 | fn bar<T: &Trait>(_: T) {}
| ^ expected one of 10 possible tokens
```
After:
```text
error: expected a trait, found type
--> <anon>:2:16
|
2 | fn foo(_: impl &Trait) {}
| -^^^^^
| |
| help: consider removing the indirection
error: expected a trait, found type
--> <anon>:3:11
|
3 | fn bar<T: &Trait>(_: T) {}
| -^^^^^
| |
| help: consider removing the indirection
```
suggestion for attempted integer identifier in patterns
Fixes#106552
Implemented a suggestion on `E0005` that occurs when no bindings are present and the pattern is a literal integer.
Heuristically undo path prefix mappings.
Because the compiler produces better diagnostics if it can find the source of (potentially remapped) dependencies.
The new test fails without the other changes in this PR. Let me know if you have better suggestions for the test directory. I moved the existing remapping test to be in the same location as the new one.
Some more context: I'm exploring running UI tests with remapped paths by default in https://github.com/rust-lang/rust/pull/105924 and this was one of the issues discovered.
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").
Emit only one nbsp error per file
Fixes#106101.
See https://github.com/rust-lang/rust/issues/106098 for an explanation of how someone would end up with a large number of these nbsp characters in their source code, which is why I think rustc needs to handle this specific case in a friendlier way.
Rollup of 5 pull requests
Successful merges:
- #106888 (Add tidy check to ensure that rustdoc GUI tests start with a small description)
- #106896 (suggest `is_empty` for collections when casting to `bool`)
- #106900 (Fix regression in `unused_braces` with macros)
- #106906 (remove redundant clones)
- #106909 (Only suggest adding type param if path being resolved was a type)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
suggest `is_empty` for collections when casting to `bool`
Fixes#106883
Matches on slices, `String` and `str`. It would be nice to do this with something like `Deref<Target=str>` as well, but AFAIK it's not possible in this part of the compiler.
Add tidy check to ensure that rustdoc GUI tests start with a small description
The first commit comes from https://github.com/rust-lang/rust/pull/106865 to prevent CI to fail.
This PR adds a tidy check to enforce having a small description at the top of the GUI test. Although the format is made to be as easy as possible to read, it's not always obvious what a test is actually checking. I think enforcing this will make it easier for us to come back on these tests if needed.
r? `@notriddle`
Simplify manual ptr arithmetic in slice::Iter with ptr_sub
The old code was introduced in #61885, which predates the ptr_sub method and underlying intrinsic. The codegen test still passes.
r? `@scottmcm`
The optimization that removes artifacts when building libraries is correct
from the compiler's perspective but not from a debugger's perspective.
Unpacked split debuginfo is referred to by filename and debuggers need
the artifact that contains debuginfo to continue to exist at that path.
Ironically the test expects the correct behavior but it was not running.
Consolidate two almost duplicated fn info extraction routines
Moves `extract_callable_info` up to trait selection, because it was being (almost) duplicated fully there for similar diagnostic purposes. This also generalizes the diagnostics we can give slightly (see UI test).
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.
This class originated in the very first commit of `rustdoc_ng`, and was used
to add a color border around the item decl based on its kind.
4fd061c426/src/rustdoc_ng/html/static/main.css (L102-L106)
The item decl no longer has a border, and there aren't any
kind-specific styles in modern rustdoc's rendering of this UI item.
Most of this commit is updating test cases so that they use `item-decl` to
find the `<pre>` tag instead of relying on the fact that the class name
had `rust {kind}` in it while other `<pre>` tags only had class `rust`.
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
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).
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
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).
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").
rustdoc: rename CSS rustdoc-toggle -> toggle and toggle -> settings-toggle
This swaps things around so that the class that gets used more often has the shorter name.
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
Normalize test output more thoroughly
This prevents differences in local environments, which may (for example) end up with a longer backtrace with more digits in the backtrace prefix, as happened to me. While we're at it, clean more of the output up, including the exact location of the error in the compiler.
cc https://github.com/rust-lang/rust/pull/106521 which introduced this test
Warn when using panic-strategy abort for proc-macro crates
See https://github.com/rust-lang/rust/issues/82320, this simply warns for now as that seems like the best step that can be immediately taken (opposed to straight up rejecting or ignoring)
Bump `IMPLIED_BOUNDS_ENTAILMENT` to Deny + ReportNow
https://github.com/rust-lang/rust/pull/105575#issuecomment-1357201969
> and then later in the same cycle increase the lint to `deny` and change it to `FutureCompatReportNow` in this nightly cycle.
r? ```@lcnr``` when they're back from holiday 😄
Add log-backtrace option to show backtraces along with logging
according to #90698, I added a compiler option, `-Zlog-backtrace=filter`, where `filter` is a module name, to show backtraces for logging without rebuilding.
resolve#90698
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.
Render missing generics suggestion verbosely
It's a bit easier to read like this, especially ones that are appending new generics onto an existing list, like ": `, T`" which render somewhat poorly inline.
Also don't suggest `dyn` as a type parameter to add, even if technically that's valid in edition 2015.
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.
This prevents differences in local environments, which may (for example)
end up with a longer backtrace with more digits in the backtrace prefix,
as happened to me. While we're at it, clean more of the output up,
including the exact location of the error in the compiler.
Revert "Make nested RPITIT inherit the parent opaque's generics."
This reverts commit e2d41f4c97, and adjusts the `tests/ui/async-await/in-trait/nested-rpit.rs` test.
r? `@cjgillot`
fixes#106332, manually verified because it had no minimization :/
reopens#105197
cc #106729
Fix reexport of `doc(hidden)` item
Part of #59368.
It doesn't fix the `doc(inline)` nor the `doc(hidden)` on macro. I'll do it in a follow-up PR.
r? `@notriddle`
Mark ZST as FFI-safe if all its fields are PhantomData
This presents one possible solution to issue: #106629.
This is my first (tentative) contribution to the compiler itself.
I'm looking forward for comments and feedback
Closes: #106629
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.
Handle inference variables in `CollectAllMismatches` correctly
1. Fix#106240
2. Treat int/float type variables correctly (see `src/test/ui/iterators/invalid-iterator-chain-with-int-infer.rs`), so we can point out things like "`Iterator::Item` changed to `{integer}` here"
Harden the pre-tyctxt query system against accidental recomputation
While the current compiler has no issues where we `take` and then compute the query again, in https://github.com/rust-lang/rust/pull/105462 I accidentally introduced such a case.
I also took the opportunity to remove `peek_mut`, which is only ever used for `global_tcx` to then invoke `enter`. I added an `enter` method directly on the query.
Migrate mir_build diagnostics 2 of 3
The first three commits are fairly boring, however I've made some changes to the output of the match checking diagnostics.
Stabilize `::{core,std}::pin::pin!`
As discussed [over here](https://github.com/rust-lang/rust/issues/93178#issuecomment-1295843548), it looks like a decent time to stabilize the `pin!` macro.
### Public API
```rust
// in module `core::pin`
/// API: `fn pin<T>($value: T) -> Pin<&'local mut T>`
pub macro pin($value:expr $(,)?) {
…
}
```
- Tracking issue: #93178
(now all this needs is an FCP by the proper team?)
Allow codegen to unsize `dyn*` to `dyn`
`dyn* Trait` is just another type that implements `Trait`, so we should be able to unsize `&dyn* Trait` into `&dyn Trait` perfectly fine, same for `Box` and other unsizeable types.
Fixes#106488
Prefer non-`[type error]` candidates during selection
Fixes#102130Fixes#106351
r? types
note: Alternatively we could filter out error where-clauses during param-env construction? But we still need to filter out impls with errors during `match_impl`, I think.
Fix invalid syntax and incomplete suggestion in impl Trait parameter type suggestions for E0311
Fixes#105544
The problems: The suggestion given for E0311 has invalid syntax when the synthetic type parameter is used for Trait type in function declaration:
```rust
fn foo(d: impl Sized) -> impl Sized
```
instead of explicitly specified like the following:
```rust
fn foo<T: Sized>(d: T) -> impl Sized
```
In addition to the syntax error, the suggestions given for E0311 are not complete when multiple elided lifetimes are involved in lifetime bounds, not all involved parameters are given the named lifetime in the suggestions. For the following test case:
```
fn foo(d: impl Sized, p: &mut ()) -> impl Sized + '_ {
(d, p)
}
```
a good suggestion should add the lifetime 'a to both d and p, instead of d only:
```
fn foo<'a>(d: impl Sized + 'a, p: &'a mut ()) -> impl Sized + '_ {
(d, p)
}
```
The Solution: Fix the syntax problem in the suggestions when synthetic type parameter is used, and also add lifetimes for all involved parameters.
Recover from where clauses placed before tuple struct bodies
Open to any suggestions regarding the phrasing of the diagnostic.
Fixes#100790.
`@rustbot` label A-diagnostics
r? diagnostics
Note predicate span on `ImplDerivedObligation`
Seems obvious to point out the where-clause that introduces the `ImplDerivedObligation` :)
r? `@estebank`
