Put the core unit tests in a separate coretests package
Having standard library tests in the same package as a standard library crate has bad side effects. It causes the test to have a dependency on a locally built standard library crate, while also indirectly depending on it through libtest. Currently this works out fine in the context of rust's build system as both copies are identical, but for example in cg_clif's tests I've found it basically impossible to compile both copies with the exact same compiler flags and thus the two copies would cause lang item conflicts.
This PR moves the tests of libcore to a separate package which doesn't depend on libcore, thus preventing the duplicate crates even when compiler flags don't exactly match between building the sysroot (for libtest) and building the test itself. The rest of the standard library crates do still have this issue however.
Add some tracing to core bootstrap logic
Follow-up to #135391.
### Summary
Add some initial tracing logging to bootstrap, focused on the core logic (in this PR).
Also:
- Adjusted tracing-tree style to not use indent lines (I found that more distracting than helpful).
- Avoid glob-importing `tracing` items.
- Improve the rustc-dev-guide docs on bootstrap tracing.
### Example output
```bash
$ BOOTSTRAP_TRACING=bootstrap=TRACE ./x check src/bootstrap
```

r? bootstrap
Uplift `clippy::double_neg` lint as `double_negations`
Warns about cases like this:
```rust
fn main() {
let x = 1;
let _b = --x; //~ WARN use of a double negation
}
```
The intent is to keep people from thinking that `--x` is a prefix decrement operator. `++x`, `x++` and `x--` are invalid expressions and already have a helpful diagnostic.
I didn't add a machine-applicable suggestion to the lint because it's not entirely clear what the programmer was trying to achieve with the `--x` operation. The code that triggers the lint should always be reviewed manually.
Closes#82987
- `check-pass` test for a MRE of #135020
- fail test for #135138
- switch to `TooGeneric` for checking CMSE fn signatures
- switch to `TooGeneric` for compute `SizeSkeleton` (for transmute)
- fix broken tests
Rollup of 7 pull requests
Successful merges:
- #133631 (Support QNX 7.1 with `io-sock`+libstd and QNX 8.0 (`no_std` only))
- #134358 (compiler: Set `target_abi = "ilp32e"` on all riscv32e targets)
- #135812 (Fix GDB `OsString` provider on Windows )
- #135842 (TRPL: more backward-compatible Edition changes)
- #135946 (Remove extra whitespace from rustdoc breadcrumbs for copypasting)
- #135953 (ci.py: check the return code in `run-local`)
- #136019 (Add an `unchecked_div` alias to the `Div<NonZero<_>>` impls)
r? `@ghost`
`@rustbot` modify labels: rollup
Get rid of `mir::Const::from_ty_const`
This function is strange, because it turns valtrees into `mir::Const::Value`, but the rest of the const variants stay as type system consts.
All of the callsites except for one in `instsimplify` (array length simplification of `ptr_metadata` call) just go through the valtree arm of the function, so it's easier to just create a `mir::Const` directly for those.
For the instsimplify case, if we have a type system const we should *keep* having a type system const, rather than turning it into a `mir::Const::Value`; it doesn't really matter in practice, though, bc `usize` has no padding, but it feels more principled.
ci.py: check the return code in `run-local`
If the run fails, it should report that and return a non-zero exit
status. The simplest way to do that is with `run(..., check=True)`,
which raises a `CalledProcessError`.
Remove extra whitespace from rustdoc breadcrumbs for copypasting
The docs header used to display [item names with their full path](https://doc.rust-lang.org/1.82.0/std/os/unix/ffi/trait.OsStrExt.html), but a [recent design change](https://doc.rust-lang.org/1.83.0/std/os/unix/ffi/trait.OsStrExt.html) has split the path and added extra styling to it.
The problem is the new styling affects how this text is copied to clipboard. I used to copy and paste the paths into `use` statements in the code, but the new styling has extra formatting and whitespace that makes copied text unusable in Rust source code.
Instead of:
> std::os::unix::ffi::OsStrExt
I now get:
> std
> ::
> os
> ::
> unix
> ::
> ffi
> Trait OsStrExt
This change removes extra whitespace from the markup, and removes `display: flex`. Paths (now in small text) are unlikely to be that long to wrap, and even then regular text wrapping should be sufficient.
TRPL: more backward-compatible Edition changes
- Improve the discussion of `unsafe` blocks within `unsafe` functions.
- Fix formatting in Appendix A
- Incorporate line edits to Chapter 17 from NoStarch.
Fix GDB `OsString` provider on Windows
It would throw an exception due to trying to look up `Wtf8Buf.__0`. The field it actually wants is called [`bytes`](b605c65b6e/library/std/src/sys_common/wtf8.rs (L134)).
Support QNX 7.1 with `io-sock`+libstd and QNX 8.0 (`no_std` only)
Changes of this pull request:
1. Refactor code for qnx nto targets to share more code in file `nto_qnx.rs`
1. Add support for an additional network stack on nto qnx 7.1.
QNX 7.1 supports two network stacks:
1. `io-pkt`, which is default
2. `io-sock`, which is optional on 7.1 but default in QNX 8.0
As one can see in the [io-sock migration notes](https://www.qnx.com/developers/docs/7.1/index.html#com.qnx.doc.neutrino.io_sock/topic/migrate_app.html), this changes the libc API in a way similar to e.g. linux-gnu vs. linux-musl.
This change adds a new target which has a different value for `target_env`, so that e.g. libc can distinguish between both APIs.
2. Add initial support for QNX 8.0, thanks to AkhilTThomas. As it turned out, the problem with forking many processes still exists in QNX 8.0. Because if this, we are now using it for any QNX version (i.e. not check for `target_env` anymore).
Update emscripten std tests
This disables a bunch of emscripten tests that test things emscripten doesn't support and re-enables a whole bunch of tests which now work just fine on emscripten.
Tested with `EMCC_CFLAGS="-s MAXIMUM_MEMORY=2GB" ./x.py test library/ --target wasm32-unknown-emscripten`.
fix(libtest): Deprecate '--logfile'
rust-lang/testing-devex-team#9 proposed changing the behavior of `--logfile`. The given reasons were:
(1) Bazel can't programmatically process stdout. This seems like a limitation in Bazel and we recommend focusing on that. If we look at the wider Rust ecosystem, Rustc and Cargo don't support any such mechanism and the Cargo team rejected having one. Expecting this in libtest when its not supported elsewhere seems too specialized.
(2) Tests that leak out non-programmatic output that intermixes with programmatic output. We acknowledge this is a problem to be evaluated but we need to make sure we are stepping back and gathering requirements, rather than assuming `--logfile` will fit the needs.
Independent of the motive, regarding using or changing `--logfile`
(1) Most ways to do it would be a breaking change, like if we respect any stable `--format`. As suggested above, we could specialize this to new `--format` values but that would be confusing for some values to apply but not others.
(2) Other ways of solving this add new features to lib`test` when we are instead wanting to limit the feature set it has to minimize the compatibility surface that has to be maintained and the burden it would put on third party harnesses which are a focus area. Examples include `--format compact` or a `--log-format` flag
(3) The existence of `--logfile` dates back quite a ways (5cc050b265, rust-lang/rust#2127) and the history gives the
impression this more of slipped through rather than being an intended feature (see also
https://github.com/rust-lang/rust/pull/82350#discussion_r579732071). Deprecation would better match to how it has been treated. By deprecating this, we do not expect custom test harnesses (rust-lang/testing-devex-team#2) to implement this.
T-testing-devex held an FCP for deprecating in rust-lang/testing-devex-team#9 though according to
[RFC #3455](https://rust-lang.github.io/rfcs/3455-t-test.html), this is still subject to final approval from T-libs-api.
Closesrust-lang/testing-devex-team#9
Improve check-cfg expected names diagnostic
This PR improves the check-cfg `allow-same-level` test by ~~normalizing it's output and by~~ adding more context to the test.
It also filters the well known cfgs from the `expected names are` note, as to reduce the size of the diagnostic. Users can still find the full list on the [rustc book](https://doc.rust-lang.org/nightly/rustc/check-cfg.html#well-known-names-and-values), which is reinforced for Cargo users by adding a note in the Cargo check-cfg specific section.
Fixes https://github.com/rust-lang/rust/issues/135995
r? `@jieyouxu`
- Don't show environment variables. Seeing PATH is almost never useful, and it can be extremely long.
- For .rlibs in the sysroot, replace crate hashes with a `"-*"` string. This will expand to the full crate name when pasted into the shell.
- Move `.rlib` to outside the glob.
- Abbreviate the sysroot path to `<sysroot>` wherever it appears in the arguments.
This also adds an example of the linker output as a run-make test. Currently it only runs on x86_64-unknown-linux-gnu, because each platform has its own linker arguments. So that it's stable across machines, pass BUILD_ROOT as an argument through compiletest through to run-make tests.
- Only use linker-flavor=gnu-cc if we're actually going to compare the output. It doesn't exist on MacOS.
Reword resolve errors caused by likely missing crate in dep tree
Reword label and add `help`:
```
error[E0432]: unresolved import `some_novel_crate`
--> f704.rs:1:5
|
1 | use some_novel_crate::Type;
| ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
|
= help: if you wanted to use a crate named `some_novel_crate`, use `cargo add some_novel_crate` to add it to your `Cargo.toml`
```
Fix#133137.
Bootstrap: Don't move ownership of job object
I've been thinking about this since the last time I looked at bootstrap's use of job objects. We currently pass ownership of the job object to Python. I feel this is unneeded complexity.
The rationale given (in a comment) is that it helps with `ctrl-c` on `x.py`. But using `ctrl-c` when running `x.py` will also cause `bootstrap.exe` to immediately exit so I don't find that convincing.
bootstrap: Handle bootstrap lockfile race condition better
Fixes#135972
Tested by:
- Starting one build
- In another terminal, `echo -n '' > build/lock`
- Attempt to invoke bootstrap a second time
Rename test to `unresolvable-upvar-issue-87987.rs` and add some notes
Extracted from #135756. I had to figure out what this test was trying to test, so I might as well write it down for future reference.
Update cargo
5 commits in 045bf21b36a2e1f3ed85e38278d1c3cc4305e134..cecde95c119a456c30e57d3e4b31fff5a7d83df4
2025-01-17 14:59:36 +0000 to 2025-01-24 17:15:24 +0000
- Remove unused `-C link-arg=-fuse-ld=lld` (rust-lang/cargo#15097)
- Remove `unsafe` by using `LazyLock` (rust-lang/cargo#15096)
- Print globs when workspace members can't be found (rust-lang/cargo#15093)
- Make --allow-dirty imply --allow-staged (rust-lang/cargo#15013)
- fix(config): When merging, replace rather than combining specific configuration keys (rust-lang/cargo#15066)
Don't drop types with no drop glue when building drops for tailcalls
this is required as otherwise drops of `&mut` refs count as a usage of a
'two-phase temporary' causing an ICE.
fixes#128097
The underlying issue is that the current code generates drops for `&mut` which are later counted as a second use of a two-phase temporary:
`bat t.rs -p`
```rust
#![expect(incomplete_features)]
#![feature(explicit_tail_calls)]
fn f(x: &mut ()) {
let _y = String::new();
become f(x);
}
fn main() {}
```
`rustc t.rs -Zdump_mir=f`
```text
error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:298:17: found two uses for 2-phase borrow temporary _4: bb2[1] and bb3[0]
--> t.rs:6:5
|
6 | become f(x);
| ^^^^^^^^^^^
thread 'rustc' panicked at compiler/rustc_borrowck/src/borrow_set.rs:298:17:
Box<dyn Any>
stack backtrace:
[REDACTED]
error: aborting due to 1 previous error
```
`bat ./mir_dump/t.f.-------.renumber.0.mir -p -lrust`
```rust
// MIR for `f` 0 renumber
fn f(_1: &mut ()) -> () {
debug x => _1;
let mut _0: ();
let mut _2: !;
let _3: std::string::String;
let mut _4: &mut ();
scope 1 {
debug _y => _3;
}
bb0: {
StorageLive(_3);
_3 = String::new() -> [return: bb1, unwind: bb4];
}
bb1: {
FakeRead(ForLet(None), _3);
StorageLive(_4);
_4 = &mut (*_1);
drop(_3) -> [return: bb2, unwind: bb3];
}
bb2: {
StorageDead(_3);
tailcall f(Spanned { node: move _4, span: t.rs:6:14: 6:15 (#0) });
}
bb3 (cleanup): {
drop(_4) -> [return: bb4, unwind terminate(cleanup)];
}
bb4 (cleanup): {
resume;
}
}
```
Note how `_4 is moved into the tail call in `bb2` and dropped in `bb3`.
This PR adds a check that the locals we drop need dropping.
r? `@oli-obk` (feel free to reassign, I'm not sure who would be a good reviewer, but thought you might have an idea)
cc `@beepster4096,` since you wrote the original drop implementation.
If the run fails, it should report that and return a non-zero exit
status. The simplest way to do that is with `run(..., check=True)`,
which raises a `CalledProcessError`.
rust-lang/testing-devex-team#9 proposed changing the behavior of `--logfile`.
The given reasons were:
(1) Bazel can't programmatically process stdout. This seems like a
limitation in Bazel and we recommend focusing on that. If we look at
the wider Rust ecosystem, Rustc and Cargo don't support any such
mechanism and the Cargo team rejected having one. Expecting this in
libtest when its not supported elsewhere seems too specialized.
(2) Tests that leak out non-programmatic output that intermixes with
programmatic output. We acknowledge this is a problem to be evaluated
but we need to make sure we are stepping back and gathering
requirements, rather than assuming `--logfile` will fit the needs.
Independent of the motive, regarding using or changing `--logfile`
(1) Most ways to do it would be a breaking change, like if we respect
any stable `--format`. As suggested above, we could specialize this to
new `--format` values but that would be confusing for some values to
apply but not others.
(2) Other ways of solving this add new features to lib`test` when we are
instead wanting to limit the feature set it has to minimize the
compatibility surface that has to be maintained and the burden it would
put on third party harnesses which are a focus area. Examples include
`--format compact` or a `--log-format` flag
(3) The existence of `--logfile` dates back quite a ways
(5cc050b265,
rust-lang/rust#2127) and the history gives the
impression this more of slipped through rather than being an intended
feature (see also
https://github.com/rust-lang/rust/pull/82350#discussion_r579732071).
Deprecation would better match to how it has been treated.
By deprecating this, we do not expect custom test harnesses
(rust-lang/testing-devex-team#2) to implement this.
T-testing-devex held an FCP for deprecating in rust-lang/testing-devex-team#9
though according to
[RFC #3455](https://rust-lang.github.io/rfcs/3455-t-test.html),
this is still subject to final approval from T-libs-api.
ld is showing things like this:
```
ld: ignoring duplicate libraries: '-lm'
```
I don't have time or a macbook that lets me investigate these. Just silence them for now.
Tidy Python improvements
Fixes display of Python formatting diffs in tidy, and refactors the code to make it simpler and more robust. Also documents Python formatting and linting in the Rustc dev guide.
Fixes: https://github.com/rust-lang/rust/issues/135942
r? `@onur-ozkan`
Implement `needs-subprocess` directive, and cleanup a bunch of tests to use `needs-{subprocess,threads}`
### Summary
Closes#128295.
- Implements `//@ needs-subprocess` directive in compiletest as requested in #128295. However, compiletest is a host tool, so we can't just try to spawn process because that spawns the process on *host*, not the *target*, under cross-compilation scenarios.
- The short-term solution is to add *Yet Another* list of allow-list targets.
- The long-term solution is to first check if a `$target` supports std, then try to run a binary to do run-time capability detection *on the target*. But that is tricky because you have to build-and-run a binary *for the target*.
- This PR picks the short-term solution, because the long-term solution is highly non-trivial, and it's already an improvement over individual `ignore-*`s all over the place.
- Opened an issue about the long-term solution in #135928.
- Documents `//@ needs-subprocess` in rustc-dev-guide.
- Replace `ignore-{wasm,wasm32,emscripten,sgx}` with `needs-{subprocess,threads}` where suitable in tests.
- Some drive-by test changes as I was trying to figure out if I could use `needs-{subprocess,threads}` and found some bits needlessly distracting.
Count of tests that use `ignore-{wasm,wasm32,emscripten,sgx}` before and after this PR:
| State | `ignore-sgx` | `ignore-wasm` | `ignore-emscripten` |
| - | - | - | - |
| Before this PR | 96 | 88 | 207 |
| After this PR | 36 | 38 | 61 |
<details>
<summary>Commands used to find out locally</summary>
```
--- before
[17:40] Joe:rust (fresh) | rg --no-ignore -l "ignore-sgx" tests | wc -l
96
[17:40] Joe:rust (fresh) | rg --no-ignore -l "ignore-wasm" tests | wc -l
88
[17:40] Joe:rust (fresh) | rg --no-ignore -l "ignore-emscripten" tests | wc -l
207
--- after
[17:39] Joe:rust (needs-subprocess-thread) | rg --no-ignore -l "ignore-sgx" tests | wc -l
36
[17:39] Joe:rust (needs-subprocess-thread) | rg --no-ignore -l "ignore-wasm" tests | wc -l
38
[17:39] Joe:rust (needs-subprocess-thread) | rg --no-ignore -l "ignore-emscripten" tests | wc -l
61
```
</details>
### Review advice
- Best reviewed commit-by-commit.
- Non-trivial test changes (not mechanically simple replacements) are split into individual commits to help with review. Their individual commit messages give some basic description of the changes.
- I *could* split some test changes out into another PR, but I found that I needed to change some tests to `needs-threads`, some to `needs-subprocess`, and some needed to use *both*, so they might conflict and become very annoying.
---
r? ``@ghost`` (need to run try jobs)
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: i686-mingw
try-job: x86_64-mingw-1
try-job: x86_64-apple-1
try-job: aarch64-apple
try-job: aarch64-gnu
try-job: test-various
try-job: armhf-gnu
QNX SDP 8.0 comes with newly renamed QNX OS 8.0, so update the page to talk about QNX, QNX Neutrino 7.0, QNX Neutrino 7.1 or QNX OS 8.0.
Also actually add a list of target triples.