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
compiler_fence: fix example
The old example was wrong, an acquire fence is required in the signal handler. To make the point more clear, I changed the "data" variable to use non-atomic accesses.
Fixes https://github.com/rust-lang/rust/issues/133014
Move `std::io::pipe` code into its own file
Also update the docs for the new location, create a section "Platform-specific behavior", don't hide required imports for code examples.
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
Consistently use the highest bit of vector masks when converting to i1 vectors
This improves the codegen for vector `select`, `gather`, `scatter` and boolean reduction intrinsics and fixesrust-lang/portable-simd#316.
The current behavior of most mask operations during llvm codegen is to truncate the mask vector to <N x i1>, telling llvm to use the least significat bit. The exception is the `simd_bitmask` intrinsics, which already used the most signifiant bit.
Since sse/avx instructions are defined to use the most significant bit, truncating means that llvm has to insert a left shift to move the bit into the most significant position, before the mask can actually be used.
Similarly on aarch64, mask operations like blend work bit by bit, repeating the least significant bit across the whole lane involves shifting it into the sign position and then comparing against zero.
By shifting before truncating to <N x i1>, we tell llvm that we only consider the most significant bit, removing the need for additional shift instructions in the assembly.
This improves the codegen for vector `select`, `gather`, `scatter` and
boolean reduction intrinsics and fixesrust-lang/portable-simd#316.
The current behavior of most mask operations during llvm codegen is to
truncate the mask vector to <N x i1>, telling llvm to use the least
significat bit. The exception is the `simd_bitmask` intrinsics, which
already used the most signifiant bit.
Since sse/avx instructions are defined to use the most significant bit,
truncating means that llvm has to insert a left shift to move the bit
into the most significant position, before the mask can actually be
used.
Similarly on aarch64, mask operations like blend work bit by bit,
repeating the least significant bit across the whole lane involves
shifting it into the sign position and then comparing against zero.
By shifting before truncating to <N x i1>, we tell llvm that we only
consider the most significant bit, removing the need for additional
shift instructions in the assembly.
Fix tests on LLVM 20
For sparcv8plus.rs, duplicate the test for LLVM 19 and LLVM 20. LLVM 20 resolves one of the FIXME in the test.
For x86_64-bigint-add.rs split the check lines for LLVM 19 and LLVM 20. The difference in codegen here is due to a difference in unroll factor, which I believe is not what the test is interested in.
Fixes https://github.com/rust-lang/rust/issues/132957.
Fixes https://github.com/rust-lang/rust/issues/133754.
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)).
compiler: Set `target_abi = "ilp32e"` on all riscv32e targets
This allows compile-time configuration based on this. In the near future we should do this across all RISCV targets, probably, but this cfg is essential for building software usable on these targets, and they are tier 3 so it seems less of a concern to tweak their definition thusly.
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).
Rollup of 7 pull requests
Successful merges:
- #133951 (Make the wasm_c_abi future compat warning a hard error)
- #134283 (fix(libtest): Deprecate '--logfile')
- #135785 (use `PassMode::Direct` for vector types on `s390x`)
- #135948 (Update emscripten std tests)
- #135951 (Use `fmt::from_fn` in more places in the compiler)
- #136031 (Expand polonius MIR dump)
- #136032 (Account for mutable borrow in argument suggestion)
Failed merges:
- #135635 (Move `std::io::pipe` code into its own file)
r? `@ghost`
`@rustbot` modify labels: rollup
Account for mutable borrow in argument suggestion
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
instead of
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
Fix#136028.
Expand polonius MIR dump
This PR starts expanding the polonius MIR:
- switches to an HTML file, to show graphs in the same document as the MIR dump, share them more easily since it's a single file that can be hosted as a gist, and also to allow for interactivity in the near future.
- adds the regular NLL MIR + polonius constraints
- embeds a mermaid version of the CFG, similar to the graphviz one, but that needs a smaller js than `dot`'s emscripten js from graphvizonline
[Here's an example](https://gistpreview.github.io/?0c18f2a59b5e24ac0f96447aa34ffe00) of how it looks.
---
In future PRs: mermaid graphs of the NLL region graph, of the NLL SCCs, of the polonius localized outlives constraints, and the interactive polonius MIR dump.
r? ```@matthewjasper```
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`.
use `PassMode::Direct` for vector types on `s390x`
closes https://github.com/rust-lang/rust/issues/135744
tracking issue: https://github.com/rust-lang/rust/issues/130869
Previously, all vector types were type erased to `Ni8`, now we pass non-wrapped vector types directly. That skips emitting a bunch of casting logic in rustc, that LLVM then has to clean up. The initial LLVM IR is also a bit more readable.
This calling convention is tested extensively in `tests/assembly/s390x-vector-abi.rs`, showing that this change has no impact on the ABI in practice.
r? ````@taiki-e````
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