Add a lint to catch clashing `extern` fn declarations.
Closes#69390.
Adds lint `clashing_extern_decl` to detect when, within a single crate, an extern function of the same name is declared with different types. Because two symbols of the same name cannot be resolved to two different functions at link time, and one function cannot possibly have two types, a clashing extern declaration is almost certainly a mistake.
This lint does not run between crates because a project may have dependencies which both rely on the same extern function, but declare it in a different (but valid) way. For example, they may both declare an opaque type for one or more of the arguments (which would end up distinct types), or use types that are valid conversions in the language the extern fn is defined in. In these cases, we can't say that the clashing declaration is incorrect.
r? @eddyb
ci: allow gating GHA on everything but macOS
In our GitHub Actions setup macOS is too unreliable to gate on it, but the other builders work fine. This commit splits the macOS builders into a separate job (called `auto-fallible`), allowing us to gate on the auto job without failing due to macOS spurious failures.
cc https://github.com/rust-lang/rust-central-station/issues/848
r? @Mark-Simulacrum
Pre-compute `LocalDefId` <-> `HirId` mappings and remove `NodeId` <-> `HirId` conversion APIs
cc #50928
I don't know who is exactly the best person to review this.
r? @petrochenkov
lint: normalize projections using opaque types
Fixes#73251.
This PR normalizes projections which use opaque types (opaque types are otherwise linted against, which is would have previously made the test cases added in this PR fail).
core/time: Add Duration methods for zero
This patch adds two methods to `Duration`. The first, `Duration::zero`,
provides a `const` constructor for getting an zero-length duration. This
is also what `Default` provides (this was clarified in the docs), though
`default` is not `const`.
The second, `Duration::is_zero`, returns true if a `Duration` spans no
time (i.e., because its components are all zero). Previously, the way to
do this was either to compare both `as_secs` and `subsec_nanos` to 0, to
compare against `Duration::new(0, 0)`, or to use the `u128` method
`as_nanos`, none of which were particularly elegant.
Projection bound validation
During selection we use bounds declared on associated types (e.g. `type X: Copy`) to satisfy trait/projection bounds. This would be fine so long as those bounds are checked on any impls/trait objects. For simple cases they are because the bound `Self::X: Copy` gets normalized when we check the impl.
However, for default values with specialization and higher-ranked bounds from GATs or otherwise, we can't normalize when checking the impl, and so we use the bound from the trait to prove that the bound applies to the impl, which is clearly unsound.
This PR makes 2 fixes for this:
1. Requiring that the bounds on the trait apply to a projection type with the corresponding substs, so a bound `for<'a> <Self as X<'a>>::U: Copy` on the trait cannot be used to prove `<T as X<'_>>::U: Copy`.
2. Actually checking that the bounds that we still allow apply to generic/default associated types.
Opening for a crater run.
Closes#68641Closes#68642Closes#68643Closes#68644Closes#68645Closes#68656
r? @ghost
Try to suggest dereferences on trait selection failed
Fixes#39029Fixes#62530
This PR consists of two parts:
1. Decouple `Autoderef` with `FnCtxt` and move `Autoderef` to `librustc_trait_selection`.
2. Try to suggest dereferences when trait selection failed.
The first is needed because:
1. For suggesting dereferences, the struct `Autoderef` should be used. But before this PR, it is placed in `librustc_typeck`, which depends on `librustc_trait_selection`. But trait selection error emitting happens in `librustc_trait_selection`, if we want to use `Autoderef` in it, dependency loop is inevitable. So I moved the `Autoderef` to `librustc_trait_selection`.
2. Before this PR, `FnCtxt` is coupled to `Autoderef`, and `FnCtxt` only exists in `librustc_typeck`. So decoupling is needed.
After this PR, we can get suggestion like this:
```
error[E0277]: the trait bound `&Baz: Happy` is not satisfied
--> $DIR/trait-suggest-deferences-multiple.rs:34:9
|
LL | fn foo<T>(_: T) where T: Happy {}
| ----- required by this bound in `foo`
...
LL | foo(&baz);
| ^^^^
| |
| the trait `Happy` is not implemented for `&Baz`
| help: consider adding dereference here: `&***baz`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0277`.
```
r? @estebank
This patch adds two methods to `Duration`. The first, `Duration::zero`,
provides a `const` constructor for getting an zero-length duration. This
is also what `Default` provides (this was clarified in the docs), though
`default` is not `const`.
The second, `Duration::is_zero`, returns true if a `Duration` spans no
time (i.e., because its components are all zero). Previously, the way to
do this was either to compare both `as_secs` and `subsec_nanos` to 0, to
compare against `Duration::new(0, 0)`, or to use the `u128` method
`as_nanos`, none of which were particularly elegant.
Deprecate `Vec::remove_item`
In #40062 we decided to remove that method. In #71834 it was said that we want to deprecate it for a few cycles before removing it. That's what this PR does.
Prevent attacker from manipulating FPU tag word used in SGX enclave
Insufficient sanitization of the x87 FPU tag word in the trusted enclave runtime allowed unprivileged adversaries in the containing host application to induce incoherent or unexpected results for ABI-compliant compiled enclave application code that uses the x87 FPU.
Vulnerability was disclosed to us by Fritz Alder, Jo Van Bulck, David Oswald and Frank Piessens
cc: @jethrogb
ci: disable alt build during try builds
The alt build is not actually needed often, and it can be added back on a case-by-case basis if a specific PR needs access to it.
This will free up a builder.
r? @Mark-Simulacrum
RISC-V Emulated Testing
Adds a disabled docker image on which to run RISC-V tests. Based on the armhf image.
Test using
```
./src/ci/docker/run.sh riscv64gc-linux
```
cc: @msizanoen1
remove leftover mentions of `skol` and `int` from the compiler
This PR mostly changes `skol` -> `placeholder` and all cases where `int` is used as a type to `i32`.
Properly encode AnonConst into crate metadata
Fixes#68104
Previous, we were encoding AnonConst as a regular Const, causing us to
treat them differently after being deserialized in another compilation
session.
