Make sure we handle `backwards_incompatible_lint` drops appropriately in drop elaboration
In #131326, a new kind of scheduled drop (`drop_kind: DropKind::Value` + `backwards_incompatible_lint: true`) was added so that we could insert a new kind of no-op MIR statement (`backward incompatible drop`) for linting purposes.
These drops were intended to have *no side-effects*, but drop elaboration code forgot to handle these drops specially and they were handled otherwise as normal drops in most of the code. This ends up being **unsound** since we insert more than one drop call for some values, which means that `Drop::drop` could be called more than once.
This PR fixes this by splitting out the `DropKind::ForLint` and adjusting the code. I'm not totally certain if all of the places I've adjusted are either reachable or correct, but I'm pretty certain that it's *more* correct than it was previously.
cc `@dingxiangfei2009`
r? nikomatsakis
Fixes#134482
Remove a duplicated check that doesn't do anything anymore.
fixes#134005
This code didn't actually `lub` the type of the previous expressions, but just the current type over and over again. Changing it to using the actual expression type does not change anything either, so may as well remove the entire loop.
coverage: Store coverage source regions as `Span` until codegen (take 2)
This is an attempt to re-land #133418:
> Historically, coverage spans were converted into line/column coordinates during the MIR instrumentation pass.
> This PR moves that conversion step into codegen, so that coverage spans spend most of their time stored as Span instead.
> In addition to being conceptually nicer, this also reduces the size of coverage mappings in MIR, because Span is smaller than 4x u32.
That PR was reverted by #133608, because in some circumstances not covered by our test suite we were emitting coverage metadata that was causing `llvm-cov` to exit with an error (#133606).
---
The implementation here is *mostly* the same, but adapted for subsequent changes in the relevant code (e.g. #134163).
I believe that the changes in #134163 should be sufficient to prevent the problem that required the original PR to be reverted. But I haven't been able to reproduce the original breakage in a regression test, and the `llvm-cov` error message is extremely unhelpful, so I can't completely rule out the possibility of this breaking again.
r? jieyouxu (reviewer of the original PR)
compiletest: don't register predefined `MSVC`/`NONMSVC` FileCheck prefixes
This was fragile as it was based on host target passed to compiletest,
but the user could cross-compile and run test for a different target
(e.g. cross from linux to msvc, but msvc won't be set on the target).
Furthermore, it was also very surprising as normally revision names
(other than `CHECK`) was accepted as FileCheck prefixes.
This partially reverts the `MSVC`/`NONMSVC` predefined FileCheck
prefix registration introduced historically for some codegen tests.
This makes some codegen tests more verbose since they now need to
explicitly introduce `MSVC`/`NONMSVC` revisions, but I think that's
less surprising, e.g.:
```rs
//@ revisions: MSVC NONMSVC
//`@[MSVC]` only-msvc
//`@[NONMSVC]` ignore-msvc
```
Note that revisions are not *only* FileCheck prefixes in
FileCheck-based test suites, as they also can be used
to conditionally apply certain compiletest directives.
r? `@Zalathar` (or reroll a `r/? compiletest` reviewer)
try-job: x86_64-msvc
try-job: i686-msvc
try-job: x86_64-mingw-1
try-job: i686-mingw
This was fragile as it was based on host target passed to compiletest,
but the user could cross-compile and run test for a different target
(e.g. cross from linux to msvc, but msvc won't be set on the target).
Furthermore, it was also very surprising as normally revision names
(other than `CHECK`) was accepted as FileCheck prefixes.
Forbid overwriting types in typeck
While trying to figure out some type setting logic in https://github.com/rust-lang/rust/pull/134248 I realized that we sometimes set a type twice. While hopefully that would have been the same type, we didn't ensure that at all and just silently accepted it. So now we reject setting it twice, unless errors are happening, then we don't care.
Best reviewed commit by commit.
No behaviour change is intended.
Fix intra doc links not generated inside footnote definitions
Fixes#132208.
The problem was that we were running the `Footnote` "pass" before the `LinkReplacer` one. Sadly, the change is bigger than it should because we can't specialize the `Iterator` trait implementation, forcing me to add a new type to handle the other `Iterator` kind (the one which still has the `Range`).
r? ``@notriddle``
Variants::Single: do not use invalid VariantIdx for uninhabited enums
~~Stacked on top of https://github.com/rust-lang/rust/pull/133681, only the last commit is new.~~
Currently, `Variants::Single` for an empty enum contains a `VariantIdx` of 0; looking that up in the enum variant list will ICE. That's quite confusing. So let's fix that by adding a new `Variants::Empty` case for types that have 0 variants.
try-job: i686-msvc
cleanup region handling: add `LateParamRegionKind`
The second commit is to enable a split between `BoundRegionKind` and `LateParamRegionKind`, by avoiding `BoundRegionKind` where it isn't necessary.
The third comment then adds `LateParamRegionKind` to avoid having the same late-param region for separate bound regions. This fixes#124021.
r? `@compiler-errors`
Point at lint name instead of whole attr for gated lints
```
warning: unknown lint: `test_unstable_lint`
--> $DIR/warn-unknown-unstable-lint-inline.rs:4:10
|
LL | #![allow(test_unstable_lint, another_unstable_lint)]
| ^^^^^^^^^^^^^^^^^^
|
= note: the `test_unstable_lint` lint is unstable
= help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
note: the lint level is defined here
--> $DIR/warn-unknown-unstable-lint-inline.rs:3:9
|
LL | #![warn(unknown_lints)]
| ^^^^^^^^^^^^^
warning: unknown lint: `test_unstable_lint`
--> $DIR/warn-unknown-unstable-lint-inline.rs:4:29
|
LL | #![allow(test_unstable_lint, another_unstable_lint)]
| ^^^^^^^^^^^^^^^^^^^^^
|
= note: the `another_unstable_lint` lint is unstable
= help: add `#![feature(another_unstable_lint)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
```
This is particularly relevant when there are multiple lints in the same `warn` attribute. Pointing at the smaller span makes it clearer which one the warning is complaining about.
Advent of `tests/ui` (misc cleanups and improvements) [3/N]
Part of #133895.
Misc improvements to some ui tests immediately under `tests/ui/`.
Best reviewed commit-by-commit. Each commit's commit message contains further elaboration and rationale for changes.
r? compiler
-Znext-solver: modify candidate preference rules
This implements the design proposed in the FCP in #132325 and matches the old solver behavior. I hope the inline comments are all sufficiently clear, I personally think this is a fairly clear improvement over the existing approach using `fn discard_impls_shadowed_by_env`. This fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/96.
This also fixes#133639 which encounters an ICE in negative coherence when evaluating the where-clause. Given the features required to trigger this ICE 🤷
r? ``@compiler-errors``
Stabilize `#[diagnostic::do_not_recommend]`
This PR seeks to stabilize the `#[diagnostic::do_not_recommend]`attribute.
This attribute was first proposed as `#[do_not_recommend`] attribute in RFC 2397 (https://github.com/rust-lang/rfcs/pull/2397). It gives the crate authors the ability to not suggest to the compiler to not show certain traits in its error messages.
With the presence of the `#[diagnostic]` tool attribute namespace it was decided to move the attribute there, as that lowers the amount of guarantees the compiler needs to give about the exact way this influences error messages. It turns the attribute into a hint which can be ignored. In addition to the original proposed functionality this attribute now also hides the marked trait in help messages ("This trait is implemented by: ").
The attribute does not accept any argument and can only be placed on trait implementations. If it is placed somewhere else a lint warning is emitted and the attribute is otherwise ignored. If an argument is detected a lint warning is emitted and the argument is ignored. This follows the rules outlined by the diagnostic namespace.
This attribute allows crates like diesel to improve their error messages drastically. The most common example here is the following error message:
```
error[E0277]: the trait bound `&str: Expression` is not satisfied
--> /home/weiznich/Documents/rust/rust/tests/ui/diagnostic_namespace/do_not_recommend.rs:53:15
|
LL | SelectInt.check("bar");
| ^^^^^ the trait `Expression` is not implemented for `&str`, which is required by `&str: AsExpression<Integer>`
|
= help: the following other types implement trait `Expression`:
Bound<T>
SelectInt
note: required for `&str` to implement `AsExpression<Integer>`
--> /home/weiznich/Documents/rust/rust/tests/ui/diagnostic_namespace/do_not_recommend.rs:26:13
|
LL | impl<T, ST> AsExpression<ST> for T
| ^^^^^^^^^^^^^^^^ ^
LL | where
LL | T: Expression<SqlType = ST>,
| ------------------------ unsatisfied trait bound introduced here
```
By applying the new attribute to the wild card trait implementation of
`AsExpression` for `T: Expression` the error message becomes:
```
error[E0277]: the trait bound `&str: AsExpression<Integer>` is not satisfied
--> $DIR/as_expression.rs:55:15
|
LL | SelectInt.check("bar");
| ^^^^^ the trait `AsExpression<Integer>` is not implemented for `&str`
|
= help: the trait `AsExpression<Text>` is implemented for `&str`
= help: for that trait implementation, expected `Text`, found `Integer`
```
which makes it much easier for users to understand that they are facing a type mismatch.
Other explored example usages include:
* This standard library error message: https://github.com/rust-lang/rust/pull/128008
* That bevy derived example:
https://github.com/rust-lang/rust/blob/e1f306899514ea80abc1d1c9f6a57762afb304a3/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.rs (No
more tuple pyramids)
Fixes#51992
r? ``@compiler-errors``
This PR also adds a few more tests, makes sure that all the tests are run for the old and new trait solver and adds a check that the attribute does not contain arguments.
```
warning: unknown lint: `test_unstable_lint`
--> $DIR/warn-unknown-unstable-lint-inline.rs:4:10
|
LL | #![allow(test_unstable_lint, another_unstable_lint)]
| ^^^^^^^^^^^^^^^^^^
|
= note: the `test_unstable_lint` lint is unstable
= help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
note: the lint level is defined here
--> $DIR/warn-unknown-unstable-lint-inline.rs:3:9
|
LL | #![warn(unknown_lints)]
| ^^^^^^^^^^^^^
warning: unknown lint: `test_unstable_lint`
--> $DIR/warn-unknown-unstable-lint-inline.rs:4:29
|
LL | #![allow(test_unstable_lint, another_unstable_lint)]
| ^^^^^^^^^^^^^^^^^^^^^
|
= note: the `test_unstable_lint` lint is unstable
= help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
note: the lint level is defined here
--> $DIR/warn-unknown-unstable-lint-inline.rs:3:9
|
LL | #![warn(unknown_lints)]
| ^^^^^^^^^^^^^
```
This is particularly relevant when there are multiple lints in the same `warn` attribute. Pointing at the smaller span makes it clearer which one the warning is complaining about.
Use field init shorthand where possible
Field init shorthand allows writing initializers like `tcx: tcx` as
`tcx`. The compiler already uses it extensively. Fix the last few places
where it isn't yet used.
EDIT: this PR also updates `rustfmt.toml` to set
`use_field_init_shorthand = true`.
tests/assembly/asm: Remove uses of rustc_attrs and lang_items features by using minicore
Similar to https://github.com/rust-lang/rust/pull/134385 (for tests/ui/asm), but for tests/assembly/asm.
r? jieyouxu
Clarify the match ergonomics 2024 migration lint's output
This makes a few changes:
- Rather than using the whole pattern as a span for the lint, this collects spans for each problematic default binding mode reset and labels them with why they're problems.
- The lint's suggestions are now verbose-styled, so that it's clear what's being suggested vs. what's problematic.
- The wording is now less technical, and the hard error version of this diagnostic now links to the same reference material as the lint (currently an unwritten page of the edition guide).
I'm not totally confident in the wording or formatting, so I'd appreciate feedback on that in particular. I tried to draw a connection with word choice between the labels and the suggestion, but it might be imprecise, unclear, or cluttered. If so, it might be worth making the labels more terse and adding notes that explain them, but that's harder to read in a way too.
cc ```@Nadrieril``` ```@Jules-Bertholet```
Closes#133854. For reference, the error from that issue becomes:
```
error: pattern uses features incompatible with edition 2024
--> $DIR/remove-me.rs:6:25
|
LL | map.iter().filter(|(&(_x, _y), &_c)| false);
| ^ ^ cannot implicitly match against multiple layers of reference
| |
| cannot implicitly match against multiple layers of reference
|
help: make the implied reference pattern explicit
|
LL | map.iter().filter(|&(&(_x, _y), &_c)| false);
| +
```
This commit seeks to stabilize the `#[diagnostic::do_not_recommend]`
attribute.
This attribute was first proposed as `#[do_not_recommend`] attribute in
RFC 2397 (https://github.com/rust-lang/rfcs/pull/2397). It gives the
crate authors the ability to not suggest to the compiler to not show
certain traits in it's error messages. With the presence of the
`#[diagnostic]` tool attribute namespace it was decided to move the
attribute there, as that lowers the amount of guarantees the compiler
needs to give about the exact way this influences error messages. It
turns the attribute into a hint which can be ignored. In addition to the
original proposed functionality this attribute now also hides the marked
trait in help messages ("This trait is implemented by: ").
The attribute does not accept any argument and can only be placed on
trait implementations. If it is placed somewhere else a lint warning is
emitted and the attribute is otherwise ignored. If an argument is
detected a lint warning is emitted and the argument is ignored. This
follows the rules outlined by the diagnostic namespace.
This attribute allows crates like diesel to improve their error messages
drastically. The most common example here is the following error
message:
```
error[E0277]: the trait bound `&str: Expression` is not satisfied
--> /home/weiznich/Documents/rust/rust/tests/ui/diagnostic_namespace/do_not_recommend.rs:53:15
|
LL | SelectInt.check("bar");
| ^^^^^ the trait `Expression` is not implemented for `&str`, which is required by `&str: AsExpression<Integer>`
|
= help: the following other types implement trait `Expression`:
Bound<T>
SelectInt
note: required for `&str` to implement `AsExpression<Integer>`
--> /home/weiznich/Documents/rust/rust/tests/ui/diagnostic_namespace/do_not_recommend.rs:26:13
|
LL | impl<T, ST> AsExpression<ST> for T
| ^^^^^^^^^^^^^^^^ ^
LL | where
LL | T: Expression<SqlType = ST>,
| ------------------------ unsatisfied trait bound introduced here
```
By applying the new attribute to the wild card trait implementation of
`AsExpression` for `T: Expression` the error message becomes:
```
error[E0277]: the trait bound `&str: AsExpression<Integer>` is not satisfied
--> $DIR/as_expression.rs:55:15
|
LL | SelectInt.check("bar");
| ^^^^^ the trait `AsExpression<Integer>` is not implemented for `&str`
|
= help: the trait `AsExpression<Text>` is implemented for `&str`
= help: for that trait implementation, expected `Text`, found `Integer`
```
which makes it much easier for users to understand that they are facing
a type mismatch.
Other explored example usages included
* This standard library error message: https://github.com/rust-lang/rust/pull/128008
* That bevy derived example:
https://github.com/rust-lang/rust/blob/e1f306899514ea80abc1d1c9f6a57762afb304a3/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.rs (No
more tuple pyramids)
Fixes#51992
This PR aims to improve the testing coverage for
`#[diagnostic::do_not_recommend]`. It ensures that all tests are run for
the old and new solver to verify that the behaviour is the same for both
variants. It also adds two new tests:
* A test with 4 traits having wild card impl for each other, with
alternating `#[diagnostic::do_not_recommend]` attributse
* A test with a lifetime dependend wild card impl, which is something
that's not supported yet
Field init shorthand allows writing initializers like `tcx: tcx` as
`tcx`. The compiler already uses it extensively. Fix the last few places
where it isn't yet used.
bootstrap: use specific-purpose ui test path for `test_valid` self-test
I wanted to move some ui tests around in #134418, which broke `test_valid` since it was referencing two non-specific-purpose ui tests. This PR instead adds two dummy tests under `tests/ui/bootstrap/self-test/`, for that purpose specifically.
r? bootstrap
coverage: Dismantle `map_data.rs` by moving its responsibilities elsewhere
This is a series of incremental changes that combine to let us get rid of `coverageinfo/map_data.rs`, by moving all of its responsibilities into more appropriate places.
Some of the notable consequences are:
- We once again build the per-CGU file table on the fly while preparing individual covfun records, instead of building the whole table up-front. The up-front approach was introduced by #117042 to work around various other problems in generating the covmap/covfun records, but subsequent cleanups have made that approach no longer necessary.
- Expression conversion and mapping-region conversion are now performed directly in `mapgen::covfun`, which should make future changes easier.
- We no longer insert unused function instances into the same map that is also used to track used function instances. This helps to decouple the handling of used vs unused functions.
---
There should be no meaningful change to compiler output. The file table is no longer sorted, because reordering it would invalidate the file indices stored in individual covfun records, but the table order should still be deterministic (albeit arbitrary).
There are some subsequent cleanups that I intend to investigate, but this is enough change for one PR.
bors