do not attempt to prove unknowable goals
In case a goal is unknowable, we previously still checked all other possible ways to prove this goal, even though its final result is already guaranteed to be ambiguous. By ignoring all other candidates in that case we can avoid a lot of unnecessary work, fixing the performance regression in typenum found in #121848.
This is already the behavior in the old solver. This could in theory cause future-compatability issues as considering fewer goals unknowable may end up causing performance regressions/hangs. I am quite confident that this will not be an issue.
r? ``@compiler-errors``
Non-exhaustive structs may be empty
This is a follow-up to a discrepancy noticed in https://github.com/rust-lang/rust/pull/122792: today, the following struct is considered inhabited (non-empty) outside its defining crate:
```rust
#[non_exhaustive]
pub struct UninhabitedStruct {
pub never: !,
// other fields
}
```
`#[non_exhaustive]` on a struct should mean that adding fields to it isn't a breaking change. There is no way that adding fields to this struct could make it non-empty since the `never` field must stay and is inconstructible. I suspect this was implemented this way due to confusion with `#[non_exhaustive]` enums, which indeed should be considered non-empty outside their defining crate.
I propose that we consider such a struct uninhabited (empty), just like it would be without the `#[non_exhaustive]` annotation.
Code that doesn't pass today and will pass after this:
```rust
// In a different crate
fn empty_match_on_empty_struct<T>(x: UninhabitedStruct) -> T {
match x {}
}
```
This is not a breaking change.
r? ``@compiler-errors``
Don't Suggest Labeling `const` and `unsafe` Blocks
Fixes#128604
Previously, both anonymous constant blocks (E.g. The labeled block
inside `['_'; 'block: { break 'block 1 + 2; }]`) and inline const
blocks (E.g. `const { ... }`) were considered to be the same
kind of blocks. This caused the compiler to incorrectly suggest
labeling both the blocks when only anonymous constant blocks can be
labeled.
This PR adds an other enum variant to `Context` so that both the
blocks can be handled appropriately.
Also, adds some doc comments and removes unnecessary `&mut` in a
couple of places.
Suggest `impl Trait` for References to Bare Trait in Function Header
Fixes#125139
This PR suggests `impl Trait` when `&Trait` is found as a function parameter type or return type. This makes use of existing diagnostics by adding `peel_refs()` when checking for type equality.
Additionaly, it makes a few other improvements:
1. Checks if functions inside impl blocks have bare trait in their headers.
2. Introduces a trait `NextLifetimeParamName` similar to the existing `NextTypeParamName` for suggesting a lifetime name. Also, abstracts out the common logic between the two trait impls.
### Related Issues
I ran into a bunch of related diagnostic issues but couldn't fix them within the scope of this PR. So, I have created the following issues:
1. [Misleading Suggestion when Returning a Reference to a Bare Trait from a Function](https://github.com/rust-lang/rust/issues/127689)
2. [Verbose Error When a Function Takes a Bare Trait as Parameter](https://github.com/rust-lang/rust/issues/127690)
3. [Incorrect Suggestion when Returning a Bare Trait from a Function](https://github.com/rust-lang/rust/issues/127691)
r? ```@estebank``` since you implemented #119148
Replace walk with visit so we dont skip outermost expr kind in def collector
This affects async closures with macros as their body expr. Fixes#129855.
r? ``@cjgillot`` or anyone else
Actually parse stdout json, instead of using hacky contains logic.
Fixes up the test added in #128963, to actually parse the stdout to JSON, instead of just checking that it contains `{"`.
CC ``@GuillaumeGomez``
r? ``@jieyouxu``
Deny imports of `rustc_type_ir::inherent` outside of type ir + new trait solver
We shouldn't encourage using `rustc_type_ir::inherent` outside of the new solver[^1], though this can happen by accident due to rust-analyzer, for example. See https://github.com/rust-lang/rust/pull/127537#discussion_r1733813842 for an example in practice.
r? fmease
[^1]: Unless we go the fully radical approach of always using these inherent methods everywhere in favor of inherent methods, which would be a major overhaul of the compiler, IMO. I don't really want to consider that possibility right now, tho.
Rewrite lint_expectations in a single pass.
This PR aims at reducing the perf regression from https://github.com/rust-lang/rust/pull/120924#issuecomment-2202486203 with drive-by simplifications.
Basically, instead of using the lint level builder, which is slow, this PR splits `lint_expectations` logic in 2:
- listing the `LintExpectations` is done in `shallow_lint_levels_on`, on a per-owner basis;
- building the unstable->stable expectation id map is done by iterating on attributes.
r? ghost for perf
add `aarch64_unknown_nto_qnx700` target - QNX 7.0 support for aarch64le
This backports the QNX 7.1 aarch64 implementation to 7.0.
* [x] required `-lregex` disabled, see https://github.com/rust-lang/libc/pull/3775 (released in libc 0.2.156)
* [x] uses `libgcc.a` instead of `libgcc_s.so` (7.0 used ancient GCC 5.4 which didn't have gcc_s)
* [x] a fix in `backtrace` crate to support stack traces https://github.com/rust-lang/backtrace-rs/pull/648
This PR bumps libc dependency to 0.2.158
CC: to the folks who did the [initial implementation](https://doc.rust-lang.org/rustc/platform-support/nto-qnx.html): `@flba-eb,` `@gh-tr,` `@jonathanpallant,` `@japaric`
# Compile target
```bash
# Configure qcc build environment
source _path_/_to_/qnx7.0/qnxsdp-env.sh
# Tell rust to use qcc when building QNX 7.0 targets
export build_env='
CC_aarch64-unknown-nto-qnx700=qcc
CFLAGS_aarch64-unknown-nto-qnx700=-Vgcc_ntoaarch64le_cxx
CXX_aarch64-unknown-nto-qnx700=qcc
AR_aarch64_unknown_nto_qnx700=ntoaarch64-ar'
# Build rust compiler, libs, and the remote test server
env $build_env ./x.py build \
--target x86_64-unknown-linux-gnu,aarch64-unknown-nto-qnx700 \
rustc library/core library/alloc library/std src/tools/remote-test-server
rustup toolchain link stage1 build/host/stage1
```
# Compile "hello world"
```bash
source _path_/_to_/qnx7.0/qnxsdp-env.sh
cargo new hello_world
cd hello_world
cargo +stage1 build --release --target aarch64-unknown-nto-qnx700
```
# Configure a remote for testing
Do this from a new shell - we will need to run more commands in the previous one. I ran into these two issues, and found some workarounds.
* Temporary dir might not work properly
* Default `remote-test-server` has issues binding to an address
```
# ./remote-test-server
starting test server
thread 'main' panicked at src/tools/remote-test-server/src/main.rs:175:29:
called `Result::unwrap()` on an `Err` value: Os { code: 249, kind: AddrNotAvailable, message: "Can't assign requested address" }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
Specifying `--bind` param actually fixes that, and so does setting `TMPDIR` properly.
```bash
# Copy remote-test-server to remote device. You may need to use sftp instead.
# ATTENTION: Note that the path is different from the one in the remote testing documentation for some reason
scp ./build/x86_64-unknown-linux-gnu/stage1-tools-bin/remote-test-server qnxdevice:/path/
# Run ssh with port forwarding - so that rust tester can connect to the local port instead
ssh -L 12345:127.0.0.1:12345 qnxdevice
# on the device, run
rm -rf tmp && mkdir -p tmp && TMPDIR=$PWD/tmp ./remote-test-server --bind 0.0.0.0:12345
```
# Run test suit
Assume all previous environment variables are still set, or re-init them
```bash
export TEST_DEVICE_ADDR="localhost:12345"
# tidy needs to be skipped due to using un-published libc dependency
export exclude_tests='
--exclude src/bootstrap
--exclude src/tools/error_index_generator
--exclude src/tools/linkchecker
--exclude src/tools/tidy
--exclude tests/ui-fulldeps
--exclude rustc
--exclude rustdoc
--exclude tests/run-make-fulldeps'
env $build_env ./x.py test $exclude_tests --stage 1 --target aarch64-unknown-nto-qnx700
```
try-job: dist-x86_64-msvc
add crashtests for several old unfixed ICEs
Adds several new crashtests for some older ICEs that did not yet have any.
Tests were added for #128097, #119095, #117460 and #126443.
Rollup of 11 pull requests
Successful merges:
- #128523 (Add release notes for 1.81.0)
- #129605 (Add missing `needs-llvm-components` directives for run-make tests that need target-specific codegen)
- #129650 (Clean up `library/profiler_builtins/build.rs`)
- #129651 (skip stage 0 target check if `BOOTSTRAP_SKIP_TARGET_SANITY` is set)
- #129684 (Enable Miri to pass pointers through FFI)
- #129762 (Update the `wasm-component-ld` binary dependency)
- #129782 (couple more crash tests)
- #129816 (tidy: say which feature gate has a stability issue mismatch)
- #129818 (make the const-unstable-in-stable error more clear)
- #129824 (Fix code examples buttons not appearing on click on mobile)
- #129826 (library: Fix typo in `core::mem`)
r? `@ghost`
`@rustbot` modify labels: rollup
make the const-unstable-in-stable error more clear
The default should be to add `rustc_const_unstable`, not `rustc_allow_const_fn_unstable`.
Also I discovered our check for missing const stability attributes on stable functions -- but strangely that check only kicks in for "reachable" functions. `check_missing_stability` checks for reachability since all reachable functions must have a stability attribute, but I would say if a function has `#[stable]` it should also have const-stability attributes regardless of reachability.
Add missing `needs-llvm-components` directives for run-make tests that need target-specific codegen
Without suitable `needs-llvm-components` directives, some run-make tests exercising target-specific codegen can fail if the LLVM used is built without the necessary components. Currently, the list is:
```
tests\run-make\print-target-list
tests\run-make\print-to-output
tests\run-make\print-cfg
tests\run-make\target-without-atomic-cas
```
This PR also skips tidy checks for revisions and `needs-llvm-components` for run-make tests since revisions are not supported.
Fixes#129390.
Fixes#127895.
cc ``@petrochenkov`` who noticed this, thanks! Would be great if you could confirm that this fixes the test errors for you locally.
