Improve diagnose for unconditional panic when resource limit
Improve diagnostic message for similar issue rust-lang/rust#115021.
When `parallel_compiler=true`, the Rust compiler frontend sets `-Z threads` to match the number of cores, which is reasonable and common. However, in a constrained environment or with an excessive number of cores (such as 377 mentioned below 😑), it could consume all resources and cause a panic.
Setting a default maximum for `-Z threads` in a parallel compiler is challenging. However, the panic error message can guide the user to check the system limit and explicitly lower the thread count according to their needs.
```
14:55:47 thread 'main' panicked at /rustc/f1586001ace26df7cafeb6534eaf76fb2c5513e5/compiler/rustc_interface/src/util.rs:216:18:
14:55:47 called `Result::unwrap()` on an `Err` value: ThreadPoolBuildError { kind: IOError(Os { code: 11, kind: WouldBlock, message: "Resource temporarily unavailable" }) }
...
14:55:47 note: compiler flags: --crate-type lib -C opt-level=z -C embed-bitcode=no -C linker=/cache/84996/rust-sdk/target/shim/aarch64-unknown-linux-ohos/clang -Z unstable-options -C symbol-mangling-version=v0 -Z panic-in-drop=abort -C codegen-units=1 -C debuginfo=1 -C embed-bitcode=yes -Z threads=377 -C link-arg=-Wl,--build-id=sha1 -Z binary-dep-depinfo
```
Add new `--bypass-ignore-backends` option
Fixes https://github.com/rust-lang/rust/issues/147063.
It adds a new option to `bootstrap` to allow to ignore `//@ ignore-backends` statements in tests.
cc ```@jieyouxu``` ```@antoyo```
r? ```@Kobzol```
Constify trait aliases
Allow `const trait Foo = Bar + [const] Baz;` trait alias declarations. Their rules are the same as with super traits of const traits. So `[const] Baz` or `const Baz` is only required for `[const] Foo` or `const Foo` bounds respectively.
tracking issue rust-lang/rust#41517 (part of the general trait alias feature gate, but I can split it out into a separate const trait alias feature gate. I just assumed that const traits would stabilize before trait aliases, and we'd want to stabilize trait aliases together with const trait aliases at the same time)
r? ``@compiler-errors`` ``@fee1-dead``
Allow check builds with binaries for the dummy codegen backend
This is likely the last part necessary for https://github.com/rust-lang/miri/pull/4648. Miri needs to be able to do a regular check build for compile_fail doc tests to work.
Move wasm `throw` intrinsic back to `unwind`
Fixesrust-lang/rust#148246, less invasive than the previously proposed rust-lang/rust#148269. Removes the publicly visible unstable intrinsic tracked in rust-lang/rust#122465 since it's not clear how to export it in a sound manner.
r? `@bjorn3`
---
rustc assumes that regular `extern "Rust"` functions unwind only if the `unwind` panic runtime is linked. `throw` was annotated as such, but unwound unconditionally. This could cause UB when a crate built with `-C panic=abort` called `throw` from `core` built with `-C panic=unwind`, since no terminator was added to handle the panic arising from calling an allegedly non-unwinding `extern "Rust"` function.
rustc was taught to recognize this condition since https://github.com/rust-lang/rust/pull/144225 and prevented such linkage, but this caused regressions in
https://github.com/rust-lang/rust/issues/148246, since this meant that Emscripten projects could not be built with `-C panic=abort` without recompiling std.
The most straightforward solution would be to move `throw` into the `panic_unwind` crate, so that it's only compiled if the panic runtime is guaranteed to be `unwind`, but this is messy due to our architecture. Instead, move it into `unwind::wasm`, which is only compiled for bare-metal targets that default to `panic = "abort"`, rendering the issue moot.
rustc assumes that regular `extern "Rust"` functions unwind only if the
`unwind` panic runtime is linked. `throw` was annotated as such, but
unwound unconditionally. This could cause UB when a crate built with `-C
panic=abort` called `throw` from `core` built with `-C panic=unwind`,
since no terminator was added to handle the panic arising from calling an
allegedly non-unwinding `extern "Rust"` function.
rustc was taught to recognize this condition since
https://github.com/rust-lang/rust/pull/144225 and prevented such
linkage, but this caused regressions in
https://github.com/rust-lang/rust/issues/148246, since this meant that
Emscripten projects could not be built with `-C panic=abort` without
recompiling std.
The most straightforward solution would be to move `throw` into the
`panic_unwind` crate, so that it's only compiled if the panic runtime is
guaranteed to be `unwind`, but this is messy due to our architecture.
Instead, move it into `unwind::wasm`, which is only compiled for
bare-metal targets that default to `panic = "abort"`, rendering the
issue moot.
Align VEX V5 boot routine to 4 bytes
This PR fixes an alignment issue with the initialization routine on the VEX V5 target.
Previously, if the `.text` output section contained any functions aligned to more than four bytes, the linker would add padding bytes before the beginning of `.text` rather than changing the position of the aligned function inside the section itself. This is an issue because the entry point for the program needs to be located at `0x3800_0020` on this platform and the addition of padding could cause it to be moved.
To fix this, I've forced the start address of the `.text` section to be aligned to 4 bytes so that the entry point is placed consistently. Items inside the section can still be aligned to values larger than this.
Handle default features and -Ctarget-features in the dummy backend
This prevents a warning about ABI relevant target features not being set on x86 and arm. In addition it is required for miri to report correct features in is_*_feature_detected!() if miri switches to the dummy backend.
Required for https://github.com/rust-lang/miri/pull/4648
[rustdoc] Include attribute and derive macros when filtering on "macros"
As discussed [here](https://github.com/rust-lang/rust/pull/147909), some filters should have been "grouped". This PR allows attribute and derive macros to match the `macro` filter.
I'll wait for https://github.com/rust-lang/rust/pull/148005 to add more tests as it would require a proc-macro library for now.
r? ```@notriddle```
rustdoc: Rename unstable option `--nocapture` to `--no-capture` in accordance with `libtest`
Context: https://github.com/rust-lang/rust/issues/133073, https://github.com/rust-lang/rust/pull/139224 (TL;DR: `libtest` has soft-deprecated `--nocapture` in favor a new & stable `--no-capture`; we should follow suit).
Since the rustdoc flag is unstable (tracking issue: https://github.com/rust-lang/rust/issues/148116), we're allowed to remove the old flag immediately. However since the flag has existed for 4 years we could hard-deprecate the flag first or at least be considerate and provide a diagnostic referring users to the new flag. This PR does neither. Let me know what you would think would be best.
Cargo doesn't use this flag, not yet at least (https://github.com/rust-lang/cargo/pull/9705), so we really are free to sunset this flag without bigger consequences.
Simplify rustc_public context handling
We no longer need two thread-local variables to store the context. We used to have two because the conversion logic used to live in a separate crate from the rest of the business logic.
I'm also merging the Container struct and the CompilerInterface trait as a single struct. This removes the unnecessary indirection and code duplication. Using a trait would also block us from adding any generic method to the compiler interface.
r? ``@oli-obk``
cc: ``@makai410``
Micro-optimization attempt in coroutine layout computation
In `compute_layout`, there were a bunch of collections (`IndexVec`s) that were being created by `push`ing in a loop, instead of a, hopefully, more performant usage of iterator combinators. [Second commit](6f682c2774) is just a small cleanup.
I'd love a perf run to see if this shows up in benchmarks.
Turn `Cow::is_borrowed,is_owned` into associated functions.
This is done because `Cow` implements `Deref`. Therefore, to avoid conflicts with an inner type having a method of the same name, we use an associated method, like `Box::into_raw`.
Tracking issue: #65143
We no longer need two thread-local variables to store the context.
We used to have two because the conversion logic used to live in a
separate crate from the rest of the business logic.
I'm also removing the Container struct and replacing the
CompilerInterface trait with a struct. This removes the unnecessary
indirection and code duplication. Using a trait would also block us
from adding any generic method to the compiler interface.
This prevents a warning about ABI relevant target features not being set
on x86 and arm. In addition it is required for miri to report correct
features in is_*_feature_detected!() if miri switches to the dummy backend.
citool: Always print a signed percentage in job duration changes
I found myself confused by these percentage deltas, because it's not immediately obvious whether a change of 110% means “a little bit worse” (+10%, 110% overall) or ”more than twice as long” (+110%, 210% overall). The correct interpretation is “more than twice as long”.
Including a sign for positive percentages should hopefully make it clearer that they are relative to a baseline of ±0%, not a baseline of 100%.
Manually tested with:
```text
cargo run --manifest-path src/ci/citool/Cargo.toml post-merge-report df984edf44c9537a94a6
```
r? Kobzol
Run regression test for #147964 on next solver too
Original regression: rust-lang/rust#147964
Longer-term tracking of issue: rust-lang/rust#148028
For now, this just makes sure that whatever tests we keep are working the same under both the current solver and the next solver, until we decide what to do with them.
Move rustdoc tests to appropriate subdirectories
## Summary
This PR reorganizes rustdoc tests into their correct subdirectories for better categorization and maintainability.
## Changes
- Moved 6 lint-related tests to `tests/rustdoc-ui/lints/`
- Moved 2 intra-doc link tests to `tests/rustdoc-ui/intra-doc/`
- Moved 3 deref-related tests to `tests/rustdoc-ui/deref/`
- Moved 1 doc-cfg test to `tests/rustdoc/doc-cfg/`
## Tests
All moved tests have been verified and pass in their new locations.
bootstrap: `ensure(doc::Std)` no longer opens a browser
In general, the rationale for `--open` is to only open HTML files if they were "explicitly" invoked from the CLI (e.g. `x doc --open library/core`). The existing logic did not do that. Instead it opened the docs unconditionally when a subset of the crates was requested. This is unfortunate for other Steps in bootstrap, which may wish to `ensure()` the standard library docs without opening them.
Change `Std` to check if it was explicitly invoked, rather than assuming it's the case.
Skip parameter attribute deduction for MIR with `spread_arg`
When a MIR argument is spread at ABI level, deduced attributes are potentially misapplied, since a spread argument can correspond to zero or more arguments at ABI level.
Disable deduction for MIR using spread argument for the time being.
Contract variable declarations
This change adds contract variables that can be declared in the `requires` clause and can be referenced both in `requires` and `ensures`, subject to usual borrow checking rules. This allows any setup common to both the `requires` and `ensures` clauses to only be done once.
In particular, one future use case would be for [Fulminate](https://dl.acm.org/doi/10.1145/3704879)-like ownership assertions in contracts, that are essentially side-effects, and executing them twice would alter the semantics of the contract.
As of this change, `requires` can now be an arbitrary sequence of statements, with the final expression being of type `bool`. They are executed in sequence as expected, before checking if the final `bool` expression holds.
This PR depends on rust-lang/rust#144438 (which has now been merged).
Contracts tracking issue: https://github.com/rust-lang/rust/issues/128044
**Other changes introduced**:
- Contract macros now wrap the content in braces to produce blocks, meaning there's no need to wrap the content in `{}` when using multiple statements. The change is backwards compatible, in that wrapping the content in `{}` still works as before. The macros also now treat `requires` and `ensures` uniformally, meaning the `requires` closure is built inside the parser, as opposed to in the macro.
**Known limiatations**:
- Contracts with variable declarations are subject to the regular borrow checking rules, and the way contracts are currently lowered limits the usefulness of contract variable declarations. Consider the below example:
```rust
#[requires(let init_x = *x; true)]
#[ensures(move |_| *x == 2 * init_x)]
fn double_in_place(x: &mut i32) {
*x *= 2;
}
```
We have used the new variable declarations feature to remember the initial value pointed to by `x`, however, moving `x` into the `ensures` does not pass the borrow checker, meaning the above function contract is illegal. Ideally, something like the above should be expressable in contracts.
Accept trivial consts based on trivial consts
This is an expansion of https://github.com/rust-lang/rust/pull/148040.
The previous implementation only accepted trivial consts that assign a literal. For example:
```rust
const A: usize = 0;
const B: usize = A;
```
Before this PR, only `A` was a trivial const. Now `B` is too.
