Fold item bounds before proving them in `check_type_bounds` in new solver
Vaguely confident that this is sufficient to prevent rust-lang/trait-system-refactor-initiative#46 and rust-lang/trait-system-refactor-initiative#62.
This is not the "correct" solution, but will probably suffice until coinduction, at which point we implement the right solution (`check_type_bounds` must prove `Assoc<...> alias-eq ConcreteType`, normalizing requires proving item bounds).
r? lcnr
Avoid unwrap diag.code directly in note_and_explain_type_err
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Fixes#125757
Rename HIR `TypeBinding` to `AssocItemConstraint` and related cleanup
Rename `hir::TypeBinding` and `ast::AssocConstraint` to `AssocItemConstraint` and update all items and locals using the old terminology.
Motivation: The terminology *type binding* is extremely outdated. "Type bindings" not only include constraints on associated *types* but also on associated *constants* (feature `associated_const_equality`) and on RPITITs of associated *functions* (feature `return_type_notation`). Hence the word *item* in the new name. Furthermore, the word *binding* commonly refers to a mapping from a binder/identifier to a "value" for some definition of "value". Its use in "type binding" made sense when equality constraints (e.g., `AssocTy = Ty`) were the only kind of associated item constraint. Nowadays however, we also have *associated type bounds* (e.g., `AssocTy: Bound`) for which the term *binding* doesn't make sense.
---
Old terminology (HIR, rustdoc):
```
`TypeBinding`: (associated) type binding
├── `Constraint`: associated type bound
└── `Equality`: (associated) equality constraint (?)
├── `Ty`: (associated) type binding
└── `Const`: associated const equality (constraint)
```
Old terminology (AST, abbrev.):
```
`AssocConstraint`
├── `Bound`
└── `Equality`
├── `Ty`
└── `Const`
```
New terminology (AST, HIR, rustdoc):
```
`AssocItemConstraint`: associated item constraint
├── `Bound`: associated type bound
└── `Equality`: associated item equality constraint OR associated item binding (for short)
├── `Ty`: associated type equality constraint OR associated type binding (for short)
└── `Const`: associated const equality constraint OR associated const binding (for short)
```
r? compiler-errors
Except for `simd-intrinsic/`, which has a lot of files containing
multiple types like `u8x64` which really are better when hand-formatted.
There is a surprising amount of two-space indenting in this directory.
Non-trivial changes:
- `rustfmt::skip` needed in `debug-column.rs` to preserve meaning of the
test.
- `rustfmt::skip` used in a few places where hand-formatting read more
nicely: `enum/enum-match.rs`
- Line number adjustments needed for the expected output of
`debug-column.rs` and `coroutine-debug.rs`.
remove tracing tree indent lines
This allows vscode to collapse nested spans without having to manually remove the indent lines. This is incredibly useful when logging the new solver. I don't mind making them optional depending on some environment flag if you prefer using indent lines
For a gist of the new output, see https://gist.github.com/lcnr/bb4360ddbc5cd4631f2fbc569057e5eb#file-example-output-L181
r? `@oli-obk`
Enable DestinationPropagation by default.
~~Based on https://github.com/rust-lang/rust/pull/115291.~~
This PR proposes to enable the destination propagation pass by default.
This pass is meant to reduce the amount of copies present in MIR.
At the same time, this PR removes the `RenameReturnPlace` pass, as it is currently unsound.
`DestinationPropagation` is not limited to `_0`, but does not handle borrowed locals.
Make `std::env::{set_var, remove_var}` unsafe in edition 2024
Allow calling these functions without `unsafe` blocks in editions up until 2021, but don't trigger the `unused_unsafe` lint for `unsafe` blocks containing these functions.
Fixes#27970.
Fixes#90308.
CC #124866.
coverage: Rename MC/DC `conditions_num` to `num_conditions`
Updated version of #124571, without the other changes that were split out into #125108 and #125700.
This value represents a quantity of conditions, not an ID, so the new spelling is more appropriate.
Some of the code touched by this PR could perhaps use some other changes, but I would prefer to keep this PR as a simple renaming and avoid scope creep.
`@rustbot` label +A-code-coverage
Make `body_owned_by` return the `Body` instead of just the `BodyId`
fixes#125677
Almost all `body_owned_by` callers immediately called `body`, too, so just return `Body` directly.
This makes the inline-const query feeding more robust, as all calls to `body_owned_by` will now yield a body for inline consts, too.
I have not yet figured out a good way to make `tcx.hir().body()` return an inline-const body, but that can be done as a follow-up
Do not equate `Const`'s ty in `super_combine_const`
Fixes#114456
In #125451 we started relating the `Const`'s tys outside of a probe so it was no longer simply an assertion to catch bugs.
This was done so that when we _do_ provide a wrongly typed const argument to an item if we wind up relating it with some other instantiation we'll have a `TypeError` we can bubble up and taint the resulting mir allowing const eval to skip evaluation.
In this PR I instead change `ConstArgHasType` to correctly handle checking the types of const inference variables. Previously if we had something like `impl<const N: u32> Trait for [(); N]`, when using the impl we would instantiate it with infer vars and then check that `?x: u32` is of type `u32` and succeed. Then later we would infer `?x` to some `Const` of type `usize`.
We now stall on `?x` in `ConstArgHasType` until it has a concrete value that we can determine the type of. This allows us to fail using the erroneous implementation of `Trait` which allows us to taint the mir.
Long term we intend to remove the `ty` field on `Const` so we would have no way of accessing the `ty` of a const inference variable anyway and would have to do this. I did not fully update `ConstArgHasType` to avoid using the `ty` field as it's not entirely possible right now- we would need to lookup `ConstArgHasType` candidates in the env.
---
As for _why_ I think we should do this, relating the types of const's is not necessary for soundness of the type system. Originally this check started off as a plain `==` in `super_relate_consts` and gradually has been growing in complexity as we support more complicated types. It was never actually required to ensure that const arguments are correctly typed for their parameters however.
The way we currently check that a const argument has the correct type is a little convoluted and confusing (and will hopefully be less weird as time goes on). Every const argument has an anon const with its return type set to type of the const parameter it is an argument to. When type checking the anon const regular type checking rules require that the expression is the same type as the return type. This effectively ensure that no matter what every const argument _always_ has the correct type.
An extra bit of complexity is that during `hir_ty_lowering` we do not represent everything as a `ConstKind::Unevaluated` corresponding to the anon const. For generic parameters i.e. `[(); N]` we simply represent them as `ConstKind::Param` as we do not want `ConstKind::Unevaluated` with generic substs on stable under min const generics. The anon const still gets type checked resulting in errors about type mismatches.
Eventually we intend to not create anon consts for all const arguments (for example for `ConstKind::Param`) and instead check that the argument type is correct via `ConstArgHasType` obligations (these effectively also act as a check that the anon consts have the correctly set return type).
What this all means is that the the only time we should ever have mismatched types when relating two `Const`s is if we have messed up our logic for ensuring that const arguments are of the correct type. Having this not be an assert is:
- Confusing as it may incorrectly lead people to believe this is an important check that is actually required
- Opens the possibility for bugs or behaviour reliant on this (unnecessary) check existing
---
This PR makes two tests go from pass->ICE (`generic_const_exprs/ice-125520-layout-mismatch-mulwithoverflow.rs` and `tests/crashes/121858.rs`). This is caused by the fact that we evaluate anon consts even if their where clauses do not hold and is a pre-existing issue and only affects `generic_const_exprs`. I am comfortable exposing the brokenness of `generic_const_exprs` more with this PR
This PR makes a test go from ICE->pass (`const-generics/issues/issue-105821.rs`). I have no idea why this PR affects that but I believe that ICE is an unrelated issue to do with the fact that under `generic_const_exprs`/`adt_const_params` we do not handle lifetimes in const parameter types correctly. This PR is likely just masking this bug.
Note: this PR doesn't re-introduce the assertion that the two consts' tys are equal. I'm not really sure how I feel about this but tbh it has caused more ICEs than its found lately so 🤷♀️
r? `@oli-obk` `@compiler-errors`
When a lazy logical operator (`&&` or `||`) occurs outside of an `if`
condition, it normally doesn't have any associated control-flow branch, so we
don't have an existing way to track whether it was true or false.
This patch adds special code to handle this case, by inserting extra MIR blocks
in a diamond shape after evaluating the RHS. This gives us a place to insert
the appropriate marker statements, which can then be given their own counters.
[ACP 362] genericize `ptr::from_raw_parts`
This implements https://github.com/rust-lang/libs-team/issues/362
As such, it can partially undo https://github.com/rust-lang/rust/pull/124795 , letting `slice_from_raw_parts` just call `from_raw_parts` again without re-introducing the unnecessary cast to MIR.
By doing this it also removes a spurious cast from `str::from_raw_parts`. And I think it does a good job of showing the value of the ACP, since the only thing that needed new turbofishing because of this is inside `ptr::null(_mut)`, but only because `ptr::without_provenance(_mut)` doesn't support pointers to extern types, which it absolutely could (without even changing the implementation).
Always use the `Fn(T) -> R` format when printing closure traits instead of `Fn<(T,), Output = R>`.
Fix#67100:
```
error[E0277]: expected a `Fn()` closure, found `F`
--> file.rs:6:13
|
6 | call_fn(f)
| ------- ^ expected an `Fn()` closure, found `F`
| |
| required by a bound introduced by this call
|
= note: wrap the `F` in a closure with no arguments: `|| { /* code */ }`
note: required by a bound in `call_fn`
--> file.rs:1:15
|
1 | fn call_fn<F: Fn() -> ()>(f: &F) {
| ^^^^^^^^^^ required by this bound in `call_fn`
help: consider further restricting this bound
|
5 | fn call_any<F: std::any::Any + Fn()>(f: &F) {
| ++++++
```
Allow calling these functions without `unsafe` blocks in editions up
until 2021, but don't trigger the `unused_unsafe` lint for `unsafe`
blocks containing these functions.
Fixes#27970.
Fixes#90308.
CC #124866.
This commit refactors the `#[do_not_recommend]` support in the old
parser to also apply to projection errors and not only to selection
errors. This allows the attribute to be used more widely.
Rollup of 7 pull requests
Successful merges:
- #124655 (Add `-Zfixed-x18`)
- #125693 (Format all source files in `tests/coverage/`)
- #125700 (coverage: Avoid overflow when the MC/DC condition limit is exceeded)
- #125705 (Reintroduce name resolution check for trying to access locals from an inline const)
- #125708 (tier 3 target policy: clarify the point about producing assembly)
- #125715 (remove unneeded extern crate in rmake test)
- #125719 (Extract coverage-specific code out of `compiletest::runtest`)
r? `@ghost`
`@rustbot` modify labels: rollup
Reintroduce name resolution check for trying to access locals from an inline const
fixes#125676
I removed this without replacement in https://github.com/rust-lang/rust/pull/124650 without considering the consequences
coverage: Avoid overflow when the MC/DC condition limit is exceeded
Fix for the test failure seen in https://github.com/rust-lang/rust/pull/124571#issuecomment-2099620869.
If we perform this subtraction first, it can sometimes overflow to -1 before the addition can bring its value back to 0.
That behaviour seems to be benign, but it nevertheless causes test failures in compiler configurations that check for overflow.
``@rustbot`` label +A-code-coverage
Format all source files in `tests/coverage/`
Currently we can't automatically enforce formatting on tests (see #125637), but we can at least keep things relatively tidy by occasionally running the formatter manually.
This was done by temporarily commenting out the `"/tests/"` exclusion in `rustfmt.toml`, and then running:
- `x fmt tests/coverage`
- `x test coverage --bless`
(This PR also includes a few cosmetic tweaks to some of the affected files, to convince rustfmt to format them in the way we want.)
``@rustbot`` label +A-code-coverage
Use `rmake` for `windows-` run-make tests
Convert some Makefile tests to recipes.
I renamed "issue-85441" to "windows-ws2_32" as I think it's slightly more descriptive. EDIT: `llvm-readobj` seems to work for reading DLL imports so I've used that instead of `objdump`.
cc #121876
Make lint: `lint_dropping_references` `lint_forgetting_copy_types` `lint_forgetting_references` give suggestion if possible.
This is a follow-up PR of #125433. When it's merged, I want change lint `dropping_copy_types` to use the same `Subdiagnostic` struct `UseLetUnderscoreIgnoreSuggestion` which is added in this PR.
Hi, Thank you(`@Urgau` ) again for your help in the previous PR. If your time permits, please also take a look at this one.
r? compiler
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don't inhibit random field reordering on repr(packed(1))
`inhibit_struct_field_reordering_opt` being false means we exclude this type from random field shuffling. However, `packed(1)` types can still be shuffled! The logic was added in https://github.com/rust-lang/rust/pull/48528 since it's pointless to reorder fields in packed(1) types (there's no padding that could be saved) -- but that shouldn't inhibit `-Zrandomize-layout` (which did not exist at the time).
We could add an optimization elsewhere to not bother sorting the fields for `repr(packed)` types, but I don't think that's worth the effort.
This *does* change the behavior in that we may now reorder fields of `packed(1)` structs (e.g. if there are niches, we'll try to move them to the start/end, according to `NicheBias`). We were always allowed to do that but so far we didn't. Quoting the [reference](https://doc.rust-lang.org/reference/type-layout.html):
> On their own, align and packed do not provide guarantees about the order of fields in the layout of a struct or the layout of an enum variant, although they may be combined with representations (such as C) which do provide such guarantees.
A small diagnostic improvement for dropping_copy_types
For a value `m` which implements `Copy` trait, `drop(m);` does nothing.
We now suggest user to ignore it by a abstract and general note: `let _ = ...`.
I think we can give a clearer note here: `let _ = m;`
fixes#125189
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Currently we can't automatically enforce formatting on tests (see #125637), but
we can at least keep things relatively tidy by occasionally running the
formatter manually.
This was done by temporarily commenting out the `"/tests/"` exclusion in
`rustfmt.toml`, and then running `x fmt tests/coverage` and
`x test coverage --bless`.
For coverage tests, splitting code across multiple lines often makes the
resulting coverage report easier to interpret, so we force rustfmt to retain
line breaks by adding dummy line comments with `//`.
Silence some resolve errors when there have been glob import errors
When encountering `use foo::*;` where `foo` fails to be found, and we later encounter resolution errors, we silence those later errors.
A single case of the above, for an *existing* import on a big codebase would otherwise have a huge number of knock-down spurious errors.
Ideally, instead of a global flag to silence all subsequent resolve errors, we'd want to introduce an unnameable binding in the appropriate rib as a sentinel when there's a failed glob import, so when we encounter a resolve error we can search for that sentinel and if found, and only then, silence that error. The current approach is just a quick proof of concept to iterate over.
Partially address #96799.
Make more of the test suite run on Mac Catalyst
Combined with https://github.com/rust-lang/rust/pull/125225, the only failing parts of the test suite are in `tests/rustdoc-js`, `tests/rustdoc-js-std` and `tests/debuginfo`. Tested with:
```console
./x test --target=aarch64-apple-ios-macabi library/std
./x test --target=aarch64-apple-ios-macabi --skip=tests/rustdoc-js --skip=tests/rustdoc-js-std --skip=tests/debuginfo tests
```
Will probably put up a PR later to enable _running_ on (not just compiling for) Mac Catalyst in CI, though not sure where exactly I should do so? `src/ci/github-actions/jobs.yml`?
Note that I've deliberately _not_ enabled stack overflow handlers on iOS/tvOS/watchOS/visionOS (see https://github.com/rust-lang/rust/issues/25872), but rather just skipped those tests, as it uses quite a few APIs that I'd be weary about getting rejected by the App Store (note that Swift doesn't do it on those platforms either).
r? ``@workingjubilee``
CC ``@thomcc``
``@rustbot`` label O-ios O-apple
Add `--print=check-cfg` to get the expected configs
This PR adds a new `--print` variant `check-cfg` to get the expected configs.
Details and rational can be found on the MCP: https://github.com/rust-lang/compiler-team/issues/743
``@rustbot`` label +F-check-cfg +S-waiting-on-MCP
r? ``@petrochenkov``
When we encounter a situation where we'd suggest `pin!()`, we now account for that expression exising 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.
The following suggestion is incorrect, as it doesn't account for the binding:
```
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 res = let mut pinned = std::pin::pin!(self.fut);
LL ~ pinned.as_mut().poll(cx);
|
```
NVPTX: Avoid PassMode::Direct for args in C abi
Fixes#117480
I must admit that I'm confused about `PassMode` altogether, is there a good sum-up threads for this anywhere? I'm especially confused about how "indirect" and "byval" goes together. To me it seems like "indirect" basically means "use a indirection through a pointer", while "byval" basically means "do not use indirection through a pointer".
The return used to keep `PassMode::Direct` for small aggregates. It turns out that `make_indirect` messes up the tests and one way to fix it is to keep `PassMode::Direct` for all aggregates. I have mostly seen this PassMode mentioned for args. Is it also a problem for returns? When experimenting with `byval` as an alternative i ran into [this assert](61a3eea804/compiler/rustc_codegen_llvm/src/abi.rs (L463C22-L463C22))
I have added tests for the same kind of types that is already tested for the "ptx-kernel" abi. The tests cannot be enabled until something like #117458 is completed and merged.
CC: ``@RalfJung`` since you seem to be the expert on this and have already helped me out tremendously
CC: ``@RDambrosio016`` in case this influence your work on `rustc_codegen_nvvm`
``@rustbot`` label +O-NVPTX
Omit non-needs_drop drop_in_place in vtables
This replaces the drop_in_place reference with null in vtables. On librustc_driver.so, this drops about ~17k (11%) dynamic relocations from the output, since many vtables can now be placed in read-only memory, rather than having a relocated pointer included.
This makes a tradeoff by adding a null check at vtable call sites. I'm not sure that's readily avoidable without changing the vtable format (e.g., so that we can use a pc-relative relocation instead of an absolute address, and avoid the dynamic relocation that way). But it seems likely that the check is cheap at runtime.
Accepted MCP: https://github.com/rust-lang/compiler-team/issues/730
When encountering `use foo::*;` where `foo` fails to be found, and we later
encounter resolution errors, we silence those later errors.
A single case of the above, for an *existing* import on a big codebase would
otherwise have a huge number of knock-down spurious errors.
Ideally, instead of a global flag to silence all subsequent resolve errors,
we'd want to introduce an unameable binding in the appropriate rib as a
sentinel when there's a failed glob import, so when we encounter a resolve
error we can search for that sentinel and if found, and only then, silence
that error. The current approach is just a quick proof of concept to
iterate over.
Partially address #96799.
This adds the `only-apple`/`ignore-apple` compiletest directive, and
uses that basically everywhere instead of `only-macos`/`ignore-macos`.
Some of the updates in `run-make` are a bit redundant, as they use
`ignore-cross-compile` and won't run on iOS - but using Apple in these
is still more correct, so I've made that change anyhow.
`-Znext-solver`: eagerly normalize when adding goals
fixes#125269. I am not totally with this fix and going to keep this open until we have a more general discussion about how to handle hangs caused by lazy norm in the new solver.
We still check for the `rental`/`allsorts-rental` crates. But now if
they are detected we just emit a fatal error, instead of emitting a
warning and providing alternative behaviour.
The original "hack" implementing alternative behaviour was added
in #73345.
The lint was added in #83127.
The tracking issue is #83125.
The direct motivation for the change is that providing the alternative
behaviour is interfering with #125174 and follow-on work.
Rollup of 4 pull requests
Successful merges:
- #125339 (The number of tests does not depend on the architecture's pointer width)
- #125542 (Migrate rustdoc verify output files)
- #125616 (MIR validation: ensure that downcast projection is followed by field projection)
- #125625 (Use grep to implement verify-line-endings)
Failed merges:
- #125573 (Migrate `run-make/allow-warnings-cmdline-stability` to `rmake.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
This replaces the drop_in_place reference with null in vtables. On
librustc_driver.so, this drops about ~17k dynamic relocations from the
output, since many vtables can now be placed in read-only memory, rather
than having a relocated pointer included.
This makes a tradeoff by adding a null check at vtable call sites.
That's hard to avoid without changing the vtable format (e.g., to use a
pc-relative relocation instead of an absolute address, and avoid the
dynamic relocation that way). But it seems likely that the check is
cheap at runtime.
rustdoc: Clarify const-stability with regard to normal stability
Fixes#125511.
- Elide const-unstable if also unstable overall
- Show "const" for const-unstable if also overall unstable
drop region constraints for ambiguous goals
See the comment in `compute_external_query_constraints`. While the underlying issue is preexisting, this fixes a bug introduced by #125343.
It slightly weakens the leak chec, even if we didn't have any test which was affected. I want to write such a test before merging this PR.
r? `@compiler-errors`
[perf] Delay the construction of early lint diag structs
Attacks some of the perf regressions from https://github.com/rust-lang/rust/pull/124417#issuecomment-2123700666.
See individual commits for details. The first three commits are not strictly necessary.
However, the 2nd one (06bc4fc671, *Remove `LintDiagnostic::msg`*) makes the main change way nicer to implement.
It's also pretty sweet on its own if I may say so myself.
Remove `DefId` from `EarlyParamRegion`
Currently we represent usages of `Region` parameters via the `ReEarlyParam` or `ReLateParam` variants. The `ReEarlyParam` is effectively equivalent to `TyKind::Param` and `ConstKind::Param` (i.e. it stores a `Symbol` and a `u32` index) however it also stores a `DefId` for the definition of the lifetime parameter.
This was used in roughly two places:
- Borrowck diagnostics instead of threading the appropriate `body_id` down to relevant locations. Interestingly there were already some places that had to pass down a `DefId` manually.
- Some opaque type checking logic was using the `DefId` field to track captured lifetimes
I've split this PR up into a commit for generate rote changes to diagnostics code to pass around a `DefId` manually everywhere, and another commit for the opaque type related changes which likely require more careful review as they might change the semantics of lints/errors.
Instead of manually passing the `DefId` around everywhere I previously tried to bundle it in with `TypeErrCtxt` but ran into issues with some call sites of `infcx.err_ctxt` being unable to provide a `DefId`, particularly places involved with trait solving and normalization. It might be worth investigating adding some new wrapper type to pass this around everywhere but I think this might be acceptable for now.
This pr also has the effect of reducing the size of `EarlyParamRegion` from 16 bytes -> 8 bytes. I wouldn't expect this to have any direct performance improvement however, other variants of `RegionKind` over `8` bytes are all because they contain a `BoundRegionKind` which is, as far as I know, mostly there for diagnostics. If we're ever able to remove this it would shrink the `RegionKind` type from `24` bytes to `12` (and with clever bit packing we might be able to get it to `8` bytes). I am curious what the performance impact would be of removing interning of `Region`'s if we ever manage to shrink `RegionKind` that much.
Sidenote: by removing the `DefId` the `Debug` output for `Region` has gotten significantly nicer. As an example see this opaque type debug print before vs after this PR:
`Opaque(DefId(0:13 ~ impl_trait_captures[aeb9]::foo::{opaque#0}), [DefId(0:9 ~ impl_trait_captures[aeb9]::foo::'a)_'a/#0, T, DefId(0:9 ~ impl_trait_captures[aeb9]::foo::'a)_'a/#0])`
`Opaque(DefId(0:13 ~ impl_trait_captures[aeb9]::foo::{opaque#0}), ['a/#0, T, 'a/#0])`
r? `@compiler-errors` (I would like someone who understands the opaque type setup to atleast review the type system commit, but the rest is likely reviewable by anyone)
If a const function is unstable overall (and thus, in all circumstances
I know of, also const-unstable), we should show the option to use it as
const. You need to enable a feature to use the function at all anyway.
If the function is stabilized without also being const-stabilized, then
we do not show the const keyword and instead show "const: unstable" in
the version info.
Don't skip out of inner const when looking for body for suggestion
Self-explanatory title, I'll point out the important logic in an inline comment.
Fixes#125370
Don't continue probing for method if in suggestion and autoderef hits ambiguity
The title is somewhat self-explanatory. When we hit ambiguity in method autoderef steps, we previously would continue to probe for methods if we were giving a suggestion. This seems useless, and causes an ICE when we are not able to unify the receiver later on in confirmation.
Fixes#125432
Support C23's Variadics Without a Named Parameter
Fixes#123773
This PR removes the static check that disallowed extern functions
with ellipsis (varargs) as the only parameter since this is now
valid in C23.
This will not break any existing code as mentioned in the proposal
document: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf.
Also, adds a doc comment for `check_decl_cvariadic_pos()` and
fixes the name of the function (`varadic` -> `variadic`).
Turn remaining non-structural-const-in-pattern lints into hard errors
This completes the implementation of https://github.com/rust-lang/rust/issues/120362 by turning our remaining future-compat lints into hard errors: indirect_structural_match and pointer_structural_match.
They have been future-compat lints for a while (indirect_structural_match for many years, pointer_structural_match since Rust 1.75 (released Dec 28, 2023)), and have shown up in dependency breakage reports since Rust 1.78 (just released on May 2, 2024). I don't expect a lot of code will still depend on them, but we will of course do a crater run.
A lot of cleanup is now possible in const_to_pat, but that is deferred to a later PR.
Fixes https://github.com/rust-lang/rust/issues/70861
It's confusing because if a function is unstable overall, there's no
need to highlight the constness is also unstable. Technically, these
attributes (overall stability and const-stability) are separate, but in
practice, we don't even show the const-unstable's feature flag (it's
normally the same as the overall function).
Stabilize `LazyCell` and `LazyLock`
Closes#109736
This stabilizes the [`LazyLock`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html) and [`LazyCell`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html) types:
```rust
static HASHMAP: LazyLock<HashMap<i32, String>> = LazyLock::new(|| {
println!("initializing");
let mut m = HashMap::new();
m.insert(13, "Spica".to_string());
m.insert(74, "Hoyten".to_string());
m
});
let lazy: LazyCell<i32> = LazyCell::new(|| {
println!("initializing");
92
});
```
r? libs-api
Add assert_unsafe_precondition to unchecked_{add,sub,neg,mul,shl,shr} methods
(Old PR is haunted, opening a new one. See #117494 for previous discussion.)
This ensures that these preconditions are actually checked in debug mode, and hopefully should let people know if they messed up. I've also replaced the calls (I could find) in the code that use these intrinsics directly with those that use these methods, so that the asserts actually apply.
More discussions on people misusing these methods in the tracking issue: https://github.com/rust-lang/rust/issues/85122.
Add manual Sync impl for ReentrantLockGuard
Fixes: #125526
Tracking Issue: #121440
this impl is even shown in the summary in the tracking issue, but apparently was forgotten in the actual implementation
Fail relating constants of different types
fixes#121585fixes#121858fixes#124151
I gave this several attempts before, but we lost too many important diagnostics until I managed to make compilation never bail out early. We have reached this point, so now we can finally fix all those ICEs by bubbling up an error instead of continueing when we encounter a bug.
The body of these benchmarks is close to empty but not literally empty.
This was making the runtime of the benchmarks (which are compiled
without optimizations!) flicker between 9 ns and 10 ns runtime, which
changes the padding and breaks the test. Recent changes to the standard
library have pushed the runtime closer to 10 ns when unoptimized, which
is why we haven't seen such failures before in CI.
Contributors can also induce such failures before this PR by running the
run-make tests while the system is under heavy load.
Warn (or error) when `Self` ctor from outer item is referenced in inner nested item
This implements a warning `SELF_CONSTRUCTOR_FROM_OUTER_ITEM` when a self constructor from an outer impl is referenced in an inner nested item. This is a proper fix mentioned https://github.com/rust-lang/rust/pull/117246#discussion_r1374648388.
This warning is additionally bumped to a hard error when the self type references generic parameters, since it's almost always going to ICE, and is basically *never* correct to do.
This also reverts part of https://github.com/rust-lang/rust/pull/117246, since I believe this is the proper fix and we shouldn't need the helper functions (`opt_param_at`/`opt_type_param`) any longer, since they shouldn't really ever be used in cases where we don't have this problem.
Resolve anon const's parent predicates to direct parent instead of opaque's parent
When an anon const is inside of an opaque, #99801 added a hack to resolve the anon const's parent predicates *not* to the opaque's predicates, but to the opaque's *parent's* predicates. This is insufficient when considering nested opaques.
This means that the `predicates_of` an anon const might reference duplicated lifetimes (installed by `compute_bidirectional_outlives_predicates`) when computing known outlives in MIR borrowck, leading to these ICEs:
Fixes#121574Fixes#118403
~~Instead, we should be using the `OpaqueTypeOrigin` to acquire the owner item (fn/type alias/etc) of the opaque, whose predicates we're fine to mention.~~
~~I think it's a bit sketchy that we're doing this at all, tbh; I think it *should* be fine for the anon const to inherit the predicates of the opaque it's located inside. However, that would also mean that we need to make sure the `generics_of` that anon const line up in the same way.~~
~~None of this is important to solve right now; I just want to fix these ICEs so we can land #125468, which accidentally fixes these issues in a different and unrelated way.~~
edit: We don't need this special case anyways because we install the right parent item in `generics_of` anyways:
213ad10c8f/compiler/rustc_hir_analysis/src/collect/generics_of.rs (L150)
r? `@BoxyUwU`
Only suppress binop error in favor of semicolon suggestion if we're in an assignment statement
Similar to #123722, we are currently too aggressive when delaying a binop error with the expectation that we'll emit another error elsewhere. This adjusts that heuristic to be more accurate, at the cost of some possibly poorer suggestions.
Fixes#125458
Don't suggest adding the unexpected cfgs to the build-script it-self
This PR adds a check to avoid suggesting to add the unexpected cfgs inside the build-script when building the build-script it-self, as it won't have any effect, since build-scripts applies to their descended target.
Fixes#125368
Migrate `run-make/issue-53964` to `rmake`
Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).
This is extremely similar to #125146. Could it be interesting to merge the two in some way? This one seems to do the same thing as the #125146, but with an added check that a useless lint is not shown.
We already handle this case this way on the coherence side, and it matches the new solver's behaviour. While there is some breakage around type-alias-impl-trait (see new "type annotations needed" in tests/ui/type-alias-impl-trait/issue-84660-unsoundness.rs), no stable code breaks, and no new stable code is accepted.
Rewrite native thread-local storage
(part of #110897)
The current native thread-local storage implementation has become quite messy, uses indescriptive names and unnecessarily adds code to the macro expansion. This PR tries to fix that by using a new implementation that also allows more layout optimizations and potentially increases performance by eliminating unnecessary TLS accesses.
This does not change the recursive initialization behaviour I described in [this comment](https://github.com/rust-lang/rust/issues/110897#issuecomment-1525705682), so it should be a library-only change. Changing that behaviour should be quite easy now, however.
r? `@m-ou-se`
`@rustbot` label +T-libs
Rewrite `core-no-oom-handling`, `issue-24445` and `issue-38237` `run-make` tests to new `rmake.rs` format
Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).
The test which is now called `non-pie-thread-local` has an unexplained "only-linux" flag. Could it be worth trying to remove it and changing the CI to test non-Linux platforms on it?
Use correct param-env in `MissingCopyImplementations`
We shouldn't assume the param-env is empty for this lint, since although we check the struct has no parameters, there still may be trivial where-clauses.
fixes#125394
Cleanup: Fix up some diagnostics
Several diagnostics contained their error code inside their primary message which is no bueno.
This PR moves them out of the message and turns them into structured error codes.
Also fixes another occurrence of `->` after a selector in a Fluent message which is not correct. I've fixed two other instances of this issue in #104345 (2022) but didn't update all instances as I've noted here: https://github.com/rust-lang/rust/pull/104345#issuecomment-1312705977 (“the future is now!”).
Allow coercing functions whose signature differs in opaque types in their defining scope into a shared function pointer type
r? `@compiler-errors`
This accepts more code on stable. It is now possible to have match arms return a function item `foo` and a different function item `bar` in another, and that will constrain OpaqueTypeInDefiningScope to have the hidden type ConcreteType and make the type of the match arms a function pointer that matches the signature. So the following function will now compile, but on master it errors with a type mismatch on the second match arm
```rust
fn foo<T>(t: T) -> T {
t
}
fn bar<T>(t: T) -> T {
t
}
fn k() -> impl Sized {
fn bind<T, F: FnOnce(T) -> T>(_: T, f: F) -> F {
f
}
let x = match true {
true => {
let f = foo;
bind(k(), f)
}
false => bar::<()>,
};
todo!()
}
```
cc https://github.com/rust-lang/rust/issues/116652
This is very similar to https://github.com/rust-lang/rust/pull/123794, and with the same rationale:
> this is for consistency with `-Znext-solver`. the new solver does not have the concept of "non-defining use of opaque" right now and we would like to ideally keep it that way. Moving to `DefineOpaqueTypes::Yes` in more cases removes subtlety from the type system. Right now we have to be careful when relating `Opaque` with another type as the behavior changes depending on whether we later use the `Opaque` or its hidden type directly (even though they are equal), if that later use is with `DefineOpaqueTypes::No`*
Expand `for_loops_over_fallibles` lint to lint on fallibles behind references.
Extends the scope of the (warn-by-default) lint `for_loops_over_fallibles` from just `for _ in x` where `x: Option<_>/Result<_, _>` to also cover `x: &(mut) Option<_>/Result<_>`
```rs
fn main() {
// Current lints
for _ in Some(42) {}
for _ in Ok::<_, i32>(42) {}
// New lints
for _ in &Some(42) {}
for _ in &mut Some(42) {}
for _ in &Ok::<_, i32>(42) {}
for _ in &mut Ok::<_, i32>(42) {}
// Should not lint
for _ in Some(42).into_iter() {}
for _ in Some(42).iter() {}
for _ in Some(42).iter_mut() {}
for _ in Ok::<_, i32>(42).into_iter() {}
for _ in Ok::<_, i32>(42).iter() {}
for _ in Ok::<_, i32>(42).iter_mut() {}
}
```
<details><summary><code>cargo build</code> diff</summary>
```diff
diff --git a/old.out b/new.out
index 84215aa..ca195a7 100644
--- a/old.out
+++ b/new.out
`@@` -1,33 +1,93 `@@`
warning: for loop over an `Option`. This is more readably written as an `if let` statement
--> src/main.rs:3:14
|
3 | for _ in Some(42) {}
| ^^^^^^^^
|
= note: `#[warn(for_loops_over_fallibles)]` on by default
help: to check pattern in a loop use `while let`
|
3 | while let Some(_) = Some(42) {}
| ~~~~~~~~~~~~~~~ ~~~
help: consider using `if let` to clear intent
|
3 | if let Some(_) = Some(42) {}
| ~~~~~~~~~~~~ ~~~
warning: for loop over a `Result`. This is more readably written as an `if let` statement
--> src/main.rs:4:14
|
4 | for _ in Ok::<_, i32>(42) {}
| ^^^^^^^^^^^^^^^^
|
help: to check pattern in a loop use `while let`
|
4 | while let Ok(_) = Ok::<_, i32>(42) {}
| ~~~~~~~~~~~~~ ~~~
help: consider using `if let` to clear intent
|
4 | if let Ok(_) = Ok::<_, i32>(42) {}
| ~~~~~~~~~~ ~~~
-warning: `for-loops-over-fallibles` (bin "for-loops-over-fallibles") generated 2 warnings
- Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.04s
+warning: for loop over a `&Option`. This is more readably written as an `if let` statement
+ --> src/main.rs:7:14
+ |
+7 | for _ in &Some(42) {}
+ | ^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+7 | while let Some(_) = &Some(42) {}
+ | ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+7 | if let Some(_) = &Some(42) {}
+ | ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `&mut Option`. This is more readably written as an `if let` statement
+ --> src/main.rs:8:14
+ |
+8 | for _ in &mut Some(42) {}
+ | ^^^^^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+8 | while let Some(_) = &mut Some(42) {}
+ | ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+8 | if let Some(_) = &mut Some(42) {}
+ | ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `&Result`. This is more readably written as an `if let` statement
+ --> src/main.rs:9:14
+ |
+9 | for _ in &Ok::<_, i32>(42) {}
+ | ^^^^^^^^^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+9 | while let Ok(_) = &Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+9 | if let Ok(_) = &Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~ ~~~
+
+warning: for loop over a `&mut Result`. This is more readably written as an `if let` statement
+ --> src/main.rs:10:14
+ |
+10 | for _ in &mut Ok::<_, i32>(42) {}
+ | ^^^^^^^^^^^^^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+10 | while let Ok(_) = &mut Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+10 | if let Ok(_) = &mut Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~ ~~~
+
+warning: `for-loops-over-fallibles` (bin "for-loops-over-fallibles") generated 6 warnings
+ Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s
```
</details>
-----
Question:
* ~~Currently, the article `an` is used for `&Option`, and `&mut Option` in the lint diagnostic, since that's what `Option` uses. Is this okay or should it be changed? (likewise, `a` is used for `&Result` and `&mut Result`)~~ The article `a` is used for `&Option`, `&mut Option`, `&Result`, `&mut Result` and (as before) `Result`. Only `Option` uses `an` (as before).
`@rustbot` label +A-lint
Fix OutsideLoop's error suggestion: adding label `'block` for `if` block.
For OutsideLoop we should not suggest add `'block` label in `if` block, or we wiil get another err: block label not supported here.
fixes#123261
Add some tests for public-private dependencies.
This adds some tests to show more scenarios for the `exported_private_dependencies` lint. Several of these illustrate that the lint is not working as expected, and I have annotated those places with `FIXME`.
Note also that this includes some diamond dependency structures which compiletest doesn't exactly support. However, I don't think it should be a problem, it just results in the common dependency being built twice.
* instead simply set the primary message inside the lint decorator functions
* it used to be this way before [#]101986 which introduced `msg` to prevent
good path delayed bugs (which no longer exist) from firing under certain
circumstances when lints were suppressed / silenced
* this is no longer necessary for various reasons I presume
* it shaves off complexity and makes further changes easier to implement
Rollup of 7 pull requests
Successful merges:
- #125043 (reference type safety invariant docs: clarification)
- #125306 (Force the inner coroutine of an async closure to `move` if the outer closure is `move` and `FnOnce`)
- #125355 (Use Backtrace::force_capture instead of Backtrace::capture in rustc_log)
- #125382 (rustdoc: rename `issue-\d+.rs` tests to have meaningful names (part 7))
- #125391 (Minor serialize/span tweaks)
- #125395 (Remove unnecessary `.md` from the documentation sidebar)
- #125399 (Stop using `to_hir_binop` in codegen)
r? `@ghost`
`@rustbot` modify labels: rollup
Force the inner coroutine of an async closure to `move` if the outer closure is `move` and `FnOnce`
See the detailed comment in `upvar.rs`.
Fixes#124867.
Fixes#124487.
r? oli-obk
An async closure may implement `FnMut`/`Fn` if it has no self-borrows
There's no reason that async closures may not implement `FnMut` or `Fn` if they don't actually borrow anything with the closure's env lifetime. Specifically, #123660 made it so that we don't always need to borrow captures from the closure's env.
See the doc comment on `should_reborrow_from_env_of_parent_coroutine_closure`:
c00957a3e2/compiler/rustc_hir_typeck/src/upvar.rs (L1777-L1823)
If there are no such borrows, then we are free to implement `FnMut` and `Fn` as permitted by our closure's inferred `ClosureKind`.
As far as I can tell, this change makes `async || {}` work in precisely the set of places they used to work before #120361.
Fixes#125247.
r? oli-obk
Disallow cast with trailing braced macro in let-else
This fixes an edge case I noticed while porting #118880 and #119062 to syn.
Previously, rustc incorrectly accepted code such as:
```rust
let foo = &std::ptr::null as &'static dyn std::ops::Fn() -> *const primitive! {
8
} else {
return;
};
```
even though a right curl brace `}` directly before `else` in a `let...else` statement is not supposed to be valid syntax.
Pattern types: Prohibit generic args on const params
Addresses https://github.com/rust-lang/rust/pull/123689/files#r1562676629.
NB: Technically speaking, *not* prohibiting generics args on const params is not a bug as `pattern_types` is an *internal* feature and as such any uncaught misuses of it are considered to be the fault of the user. However, permitting this makes me slightly uncomfortable esp. since we might want to make pattern types available to the public at some point and I don't want this oversight to be able to slip into the language (for comparison, ICEs triggered by the use of internal features are like super fine).
Furthermore, this is an ad hoc fix. A more general fix would be changing the representation of the pattern part of pattern types in such a way that it can reuse preexisting lowering routines for exprs / anon consts. See also this [Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/pattern.20type.20HIR.20nodes/near/432410768) and #124650.
Also note that we currently don't properly typeck the pattern of pat tys. This however is out of scope for this PR.
cc ``@oli-obk``
r? ``@spastorino`` as discussed
offset: allow zero-byte offset on arbitrary pointers
As per prior `@rust-lang/opsem` [discussion](https://github.com/rust-lang/opsem-team/issues/10) and [FCP](https://github.com/rust-lang/unsafe-code-guidelines/issues/472#issuecomment-1793409130):
- Zero-sized reads and writes are allowed on all sufficiently aligned pointers, including the null pointer
- Inbounds-offset-by-zero is allowed on all pointers, including the null pointer
- `offset_from` on two pointers derived from the same allocation is always allowed when they have the same address
This removes surprising UB (in particular, even C++ allows "nullptr + 0", which we currently disallow), and it brings us one step closer to an important theoretical property for our semantics ("provenance monotonicity": if operations are valid on bytes without provenance, then adding provenance can't make them invalid).
The minimum LLVM we require (v17) includes https://reviews.llvm.org/D154051, so we can finally implement this.
The `offset_from` change is needed to maintain the equivalence with `offset`: if `let ptr2 = ptr1.offset(N)` is well-defined, then `ptr2.offset_from(ptr1)` should be well-defined and return N. Now consider the case where N is 0 and `ptr1` dangles: we want to still allow offset_from here.
I think we should change offset_from further, but that's a separate discussion.
Fixes https://github.com/rust-lang/rust/issues/65108
[Tracking issue](https://github.com/rust-lang/rust/issues/117945) | [T-lang summary](https://github.com/rust-lang/rust/pull/117329#issuecomment-1951981106)
Cc `@nikic`
Make sure that the method resolution matches in `note_source_of_type_mismatch_constraint`
`note_source_of_type_mismatch_constraint` is a pile of hacks that I implemented to cover up another pile of hacks.
It does a bunch of re-confirming methods, but it wasn't previously checking that the methods it was looking (back) up were equal to the methods we previously had. This PR adds those checks.
Fixes#118185
Move `#[do_not_recommend]` to the `#[diagnostic]` namespace
This commit moves the `#[do_not_recommend]` attribute to the `#[diagnostic]` namespace. It still requires
`#![feature(do_not_recommend)]` to work.
r? `@compiler-errors`
Fix incorrect suggestion for undeclared hrtb lifetimes in where clauses.
For poly-trait-ref like `for<'a> Trait<T>` in `T: for<'a> Trait<T> + 'b { }`.
We should merge the hrtb lifetimes: existed `for<'a>` and suggestion `for<'b>` or will get err: [E0316] nested quantification of lifetimes
fixes#122714
Relax restrictions on multiple sanitizers
Most combinations of LLVM sanitizers are legal-enough to enable simultaneously. This change will allow simultaneously enabling ASAN and shadow call stacks on supported platforms.
I used this python script to generate the mutually-exclusive sanitizer combinations:
```python
#!/usr/bin/python3
import subprocess
flags = [
["-fsanitize=address"],
["-fsanitize=leak"],
["-fsanitize=memory"],
["-fsanitize=thread"],
["-fsanitize=hwaddress"],
["-fsanitize=cfi", "-flto", "-fvisibility=hidden"],
["-fsanitize=memtag", "--target=aarch64-linux-android", "-march=armv8a+memtag"],
["-fsanitize=shadow-call-stack"],
["-fsanitize=kcfi", "-flto", "-fvisibility=hidden"],
["-fsanitize=kernel-address"],
["-fsanitize=safe-stack"],
["-fsanitize=dataflow"],
]
for i in range(len(flags)):
for j in range(i):
command = ["clang++"] + flags[i] + flags[j] + ["-o", "main.o", "-c", "main.cpp"]
completed = subprocess.run(command, stderr=subprocess.DEVNULL)
if completed.returncode != 0:
first = flags[i][0][11:].replace('-', '').upper()
second = flags[j][0][11:].replace('-', '').upper()
print(f"(SanitizerSet::{first}, SanitizerSet::{second}),")
```
Add `IntoIterator` for `Box<[T]>` + edition 2024-specific lints
* Adds a similar method probe opt-out mechanism to the `[T;N]: IntoIterator` implementation for edition 2021.
* Adjusts the relevant lints (shadowed `.into_iter()` calls, new source of method ambiguity).
* Adds some tests.
* Took the liberty to rework the logic in the `ARRAY_INTO_ITER` lint, since it was kind of confusing.
Based mostly off of #116607.
ACP: rust-lang/libs-team#263
References #59878
Tracking for Rust 2024: https://github.com/rust-lang/rust/issues/123759
Crater run was done here: https://github.com/rust-lang/rust/pull/116607#issuecomment-1770293013
Consensus afaict was that there is too much breakage, so let's do this in an edition-dependent way much like `[T; N]: IntoIterator`.
Follow-up fixes to `report_return_mismatched_types`
Some renames, simplifications, fixes, etc. Follow-ups to #123804. I don't think it totally disentangles this code, but it does remove some of the worst offenders on the "I am so confused" scale (e.g. `get_node_fn_decl`).
track cycle participants per root
The search graph may have multiple roots, e.g. in
```
A :- B
B :- A, C
C :- D
D :- C
```
we first encounter the `A -> B -> A` cycle which causes `A` to be a root. We then later encounter the `C -> D -> C` cycle as a nested goal of `B`. This cycle is completely separate and `C` will get moved to the global cache. This previously caused us to use `[B, D]` as the `cycle_participants` for `C` and `[]` for `A`.
split off from #125167 as I would like to merge this change separately and will rebase that PR on top of this one. There is no test for this issue and I don't quite know how to write one. It is probably worth it to generalize the search graph to enable us to write unit tests for it.
r? `@compiler-errors`
Note for E0599 if shadowed bindings has the method.
implement #123558
Use a visitor to find earlier shadowed bingings which has the method.
r? ``@estebank``
Remove libc from MSVC targets
``@ChrisDenton`` started working on a project to remove libc from Windows MSVC targets. I'm completing that work here.
The primary change is to cfg out the dependency in `library/`. And then there's a lot of test patching. Happy to separate this more if people want.
Update `unexpected_cfgs` lint for Cargo new `check-cfg` config
This PR updates the diagnostics output of the `unexpected_cfgs` lint for Cargo new `check-cfg` config.
It's a simple and cost-less alternative to the build-script `cargo::rustc-check-cfg` instruction.
```toml
[lints.rust]
unexpected_cfgs = { level = "warn", check-cfg = ['cfg(foo, values("bar"))'] }
```
This PR also adds a Cargo specific section regarding check-cfg and Cargo inside rustc's book (motivation is described inside the file, but mainly check-cfg is a rustc feature not a Cargo one, Cargo only enabled the feature, it does not own it; T-cargo even considers the `check-cfg` lint config to be an implementation detail).
This PR also updates the links to refer to that sub-page when using Cargo from rustc.
As well as updating the lint doc to refer to the check-cfg docs.
~**Not to be merged before https://github.com/rust-lang/cargo/pull/13913 reaches master!**~ (EDIT: merged in https://github.com/rust-lang/rust/pull/125237)
`@rustbot` label +F-check-cfg
r? `@fmease` *(feel free to roll)*
Fixes https://github.com/rust-lang/rust/issues/124800
cc `@epage` `@weihanglo`
coverage: Memoize and simplify counter expressions
When creating coverage counter expressions as part of coverage instrumentation, we often end up creating obviously-redundant expressions like `c1 + (c0 - c1)`, which is equivalent to just `c0`.
To avoid doing so, this PR checks when we would create an expression matching one of 5 patterns, and uses the simplified form instead:
- `(a - b) + b` → `a`.
- `(a + b) - b` → `a`.
- `(a + b) - a` → `b`.
- `a + (b - a)` → `b`.
- `a - (a - b)` → `b`.
Of all the different ways to combine 3 operands and 2 operators, these are the patterns that allow simplification.
(Some of those patterns currently don't occur in practice, but are included anyway for completeness, to avoid having to add them later as branch coverage and MC/DC coverage support expands.)
---
This PR also adds memoization for newly-created (or newly-simplified) counter expressions, to avoid creating duplicates.
This currently makes no difference to the final mappings, but is expected to be useful for MC/DC coverage of match expressions, as proposed by https://github.com/rust-lang/rust/pull/124278#issuecomment-2106754753.
Suggest setting lifetime in borrowck error involving types with elided lifetimes
```
error: lifetime may not live long enough
--> $DIR/ex3-both-anon-regions-both-are-structs-2.rs:7:5
|
LL | fn foo(mut x: Ref, y: Ref) {
| ----- - has type `Ref<'_, '1>`
| |
| has type `Ref<'_, '2>`
LL | x.b = y.b;
| ^^^^^^^^^ assignment requires that `'1` must outlive `'2`
|
help: consider introducing a named lifetime parameter
|
LL | fn foo<'a>(mut x: Ref<'a, 'a>, y: Ref<'a, 'a>) {
| ++++ ++++++++ ++++++++
```
As can be seen above, it currently doesn't try to compare the `ty::Ty` lifetimes that diverged vs the `hir::Ty` to correctly suggest the following
```
help: consider introducing a named lifetime parameter
|
LL | fn foo<'a>(mut x: Ref<'_, 'a>, y: Ref<'_, 'a>) {
| ++++ ++++++++ ++++++++
```
but I believe this to still be an improvement over the status quo.
Fix#40990.
Fix `tests/debuginfo/strings-and-strs`.
It fails on my machine because it embeds pointer addresses in the expected output.
This commit replaces the addresses with `0x[...]`.
r? ```@Mark-Simulacrum```
defrost `RUST_MIN_STACK=ice rustc hello.rs`
I didn't think too hard about testing my previous PR rust-lang/rust#122847 which makes our stack overflow handler assist people in discovering the `RUST_MIN_STACK` variable (which apparently is surprisingly useful for Really Big codebases). After it was merged, some useful comments left in a drive-by review led me to discover I had added an ICE. This reworks the code a bit to explain the rationale, remove the ICE that I introduced, and properly test one of the diagnostics.
fix suggestion in E0373 for !Unpin coroutines
Coroutines can be prefixed with the `static` keyword to make them
`!Unpin`.
However, given the following function:
```rust
fn check() -> impl Sized {
let x = 0;
#[coroutine]
static || {
yield;
x
}
}
```
We currently suggest prefixing `move` before `static`, which is
syntactically incorrect:
```
error[E0373]: coroutine may outlive the current function, but it borrows
...
--> src/main.rs:6:5
|
6 | static || {
| ^^^^^^^^^ may outlive borrowed value `x`
7 | yield;
8 | x
| - `x` is borrowed here
|
note: coroutine is returned here
--> src/main.rs:6:5
|
6 | / static || {
7 | | yield;
8 | | x
9 | | }
| |_____^
help: to force the coroutine to take ownership of `x` (and any other
referenced variables), use the `move` keyword
| // this is syntactically incorrect, it should be `static move ||`
6 | move static || {
| ++++
```
This PR suggests adding `move` after `static` for these coroutines.
I also added a UI test for this case.
Never type unsafe lint improvements
- Move linting code to a separate method
- Remove mentions of `core::convert::absurd` (#124311 was rejected)
- Make the lint into FCW
The last thing is a bit weird though. On one hand it should be `EditionSemanticsChange(2024)`, but on the other hand it shouldn't, because we also plan to break it on all editions some time later. _Also_, it's weird that we don't have `FutureReleaseSemanticsChangeReportInDeps`, IMO "this might cause UB in a future release" is important enough to be reported in deps...
IMO we ought to have three enums instead of [`FutureIncompatibilityReason`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint_defs/enum.FutureIncompatibilityReason.html#):
```rust
enum IncompatibilityWhen {
FutureRelease,
Edition(Edition),
}
enum IncompatibilyWhat {
Error,
SemanticChange,
}
enum IncompatibilityReportInDeps {
No,
Yes,
}
```
Tracking:
- https://github.com/rust-lang/rust/issues/123748
An earlier commit included the change for a suggestion here.
Unfortunately, it also used unwrap instead of dying properly.
Roll out the ~~rice paper~~ EarlyDiagCtxt before we do anything that
might leave a mess.
chore: Remove repeated words (extension of #124924)
When I saw #124924 I thought "Hey, I'm sure that there are far more than just two typos of this nature in the codebase". So here's some more typo-fixing.
Some found with regex, some found with a spellchecker. Every single one manually reviewed by me (along with hundreds of false negatives by the tools)
Actually use the `#[do_not_recommend]` attribute if present
This change tweaks the error message generation to actually use the `#[do_not_recommend]` attribute if present by just skipping the marked trait impl in favour of the parent impl. It also adds a compile test for this behaviour. Without this change the test would output the following error:
```
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
```
Note how that mentions `&str: Expression` before and now mentions `&str: AsExpression<Integer>` instead which is much more helpful for users.
Open points for further changes before stabilization:
* We likely want to move the attribute to the `#[diagnostic]` namespace to relax the guarantees given?
* How does it interact with the new trait solver?
r? `@estebank`
This change tweaks the error message generation to actually use the
`#[do_not_recommend]` attribute if present by just skipping the marked
trait impl in favour of the parent impl. It also adds a compile test for
this behaviour. Without this change the test would output the following
error:
```
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
```
Note how that mentions `&str: Expression` before and now mentions `&str:
AsExpression<Integer>` instead which is much more helpful for users.
Open points for further changes before stabilization:
* We likely want to move the attribute to the `#[diagnostic]` namespace
to relax the guarantees given?
* How does it interact with the new trait solver?
Add tests for `-Zunpretty=expanded` ported from stringify's tests
This PR adds a new set of tests for the AST pretty-printer.
Previously, pretty-printer edge cases were tested by way of `stringify!` in [tests/ui/macros/stringify.rs](https://github.com/rust-lang/rust/blob/1.78.0/tests/ui/macros/stringify.rs), such as the tests added by 419b26931b and 527e2eac17.
Those tests will no longer provide effective coverage of the AST pretty-printer after #124141. `Nonterminal` and `TokenKind::Interpolated` are being removed, and a consequence is that `stringify!` will perform token stream pretty printing, instead of AST pretty printing, in all of the `stringify!` cases including $:expr and all other interpolations.
This PR adds 2 new ui tests with `compile-flags: -Zunpretty=expanded`:
- **tests/ui/unpretty/expanded-exhaustive.rs** — this test aims for exhaustive coverage of all the variants of `ExprKind`, `ItemKind`, `PatKind`, `StmtKind`, `TyKind`, and `VisibilityKind`. Some parts could use being fleshed out further, but the current state is roughly on par with what exists in the old stringify-based tests.
- **tests/ui/unpretty/expanded-interpolation.rs** — this test covers tricky macro metavariable edge cases that require the AST pretty printer to synthesize parentheses in order for the printed code to be valid Rust syntax.
r? `@nnethercote`
Only make GAT ambiguous in `match_projection_projections` considering shallow resolvability
In #123537, I tweaked the hack from #93892 to use `resolve_vars_if_possible` instead of `shallow_resolve`. This considers more inference guidance ambiguous. This resulted in crater regressions in #125196.
I've effectively reverted the change to the old behavior. That being said, I don't *like* this behavior, but I'd rather keep it for now since #123537 was not meant to make any behavioral changes. See the attached example.
This also affects the new solver, for the record, which doesn't have any rules about not guiding inference from param-env candidates which may constrain GAT args as a side-effect.
r? `@lcnr` or `@jackh726`
Rename Unsafe to Safety
Alternative to #124455, which is to just have one Safety enum to use everywhere, this opens the posibility of adding `ast::Safety::Safe` that's useful for unsafe extern blocks.
This leaves us today with:
```rust
enum ast::Safety {
Unsafe(Span),
Default,
// Safe (going to be added for unsafe extern blocks)
}
enum hir::Safety {
Unsafe,
Safe,
}
```
We would convert from `ast::Safety::Default` into the right Safety level according the context.
Improve parser
Fixes#124935.
- Add a few more help diagnostics to incorrect semicolons
- Overall improved that function
- Addded a few comments
- Renamed diff_marker fns to git_diff_marker
