The `Box<T: Default>` impl currently calls `T::default()` before allocating
the `Box`.
Most `Default` impls are trivial, which should in theory allow
LLVM to construct `T: Default` directly in the `Box` allocation when calling
`<Box<T>>::default()`.
However, the allocation may fail, which necessitates calling `T's` destructor if it has one.
If the destructor is non-trivial, then LLVM has a hard time proving that it's
sound to elide, which makes it construct `T` on the stack first, and then copy it into the allocation.
Create an uninit `Box` first, and then write `T::default` into it, so that LLVM now only needs to prove
that the `T::default` can't panic, which should be trivial for most `Default` impls.
Rename directive `needs-profiler-support` to `needs-profiler-runtime`
The rest of the compiler mostly refers to this as `profiler_runtime`, so having a directive named `needs-profiler-support` was causing a lot of confusion.
r? jieyouxu
Update cargo
8 commits in ad074abe3a18ce8444c06f962ceecfd056acfc73..15fbd2f607d4defc87053b8b76bf5038f2483cf4
2024-10-04 18:18:15 +0000 to 2024-10-08 21:08:11 +0000
- initial version of checksum based freshness (rust-lang/cargo#14137)
- feat: Add custom completer for completing registry name (rust-lang/cargo#14656)
- Document build-plan as being deprecated (rust-lang/cargo#14657)
- fix(complete): Don't complete files for any value (rust-lang/cargo#14653)
- Add more SAT resolver tests (rust-lang/cargo#14614)
- fix: avoid inserting duplicate `dylib_path_envvar` when calling `cargo run` recursively (rust-lang/cargo#14464)
- chore(deps): bump gix-path from 0.10.9 to 0.10.11 (rust-lang/cargo#14489)
- improve error reporting when feature not found in `activated_features` (rust-lang/cargo#14647)
---
This also adds three license exceptions to Cargo.
* arrayref — BSD-2-Clause
* blake3 — CC0-1.0 OR Apache-2.0 OR Apache-2.0 WITH LLVM-exception
* constant_time_eq — CC0-1.0 OR MIT-0 OR Apache-2.0
These exceptions were added to rustc in rust-lang/rust#126930, so should be fine for Cargo as well.
This also adds three license exceptions to Cargo.
* arrayref — BSD-2-Clause
* blake3 — CC0-1.0 OR Apache-2.0 OR Apache-2.0 WITH LLVM-exception
* constant_time_eq — CC0-1.0 OR MIT-0 OR Apache-2.0
These exceptions were added to rustc in rust-lang/rust#126930,
so should be fine for Cargo as well.
Prevent building cargo from invalidating build cache of other tools due to conditionally applied `-Zon-broken-pipe=kill` via tracked `RUSTFLAGS`
This PR fixes#130980 where building cargo invalidated the tool build caches of other tools (such as rustdoc) because `-Zon-broken-pipe=kill` was conditionally passed via `RUSTFLAGS` for other tools *except* for cargo. The differing `RUSTFLAGS` triggered tool build cache invalidation as `RUSTFLAGS` is a tracked env var -- any changes in `RUSTFLAGS` requires a rebuild.
`-Zon-broken-pipe=kill` is load-bearing for rustc and rustdoc to not ICE on broken pipes due to usages of raw std `println!` that panics without the flag being set, which manifests in ICEs.
I can't say I like the changes here, but it is what it is...
See detailed discussions and history of `-Zon-broken-pipe=kill` usage in https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Internal.20lint.20for.20raw.20.60print!.60.20and.20.60println!.60.3F/near/474593815.
## Approach
This PR fixes the tool build cache invalidation by informing the `rustc` binary shim when to apply `-Zon-broken-pipe=kill` (i.e. when the rustc binary shim is not used to build cargo). This information is not communicated by `RUSTFLAGS`, which is an env var tracked by cargo, and instead uses an untracked env var `UNTRACKED_BROKEN_PIPE_FLAG` so we won't trigger tool build cache invalidation. We preserve bootstrap's behavior of not setting that flag for cargo by conditionally omitting setting `UNTRACKED_BROKEN_PIPE_FLAG` when building cargo.
Notably, the `-Zon-broken-pipe=kill` instance in 1e5719bdc4/src/bootstrap/src/core/build_steps/compile.rs (L1058) is not modified because that is used to build rustc only and not cargo itself.
Thanks to `@cuviper` for the idea!
## Testing
### Integration testing
This PR introduces a run-make test for rustc and rustdoc that checks that when they do not ICE/panic when they encounter a broken pipe of the stdout stream.
I checked this test will catch the broken pipe ICE regression for rustc on Linux (at least) by commenting out 1e5719bdc4/src/bootstrap/src/core/build_steps/compile.rs (L1058), and the test failed because rustc ICE'd.
### Manual testing
I have manually tried:
1. `./x clean && `./x test build --stage 1` -> `rustc +stage1 --print=sysroot | false`: no ICE.
2. `./x clean` -> `./x test run-make` twice: no stage 1 cargo rebuilds.
3. `./x clean` -> `./x build rustdoc` -> `rustdoc +stage1 --version | false`: no panics.
4. `./x test src/tools/cargo`: tests pass, notably `build::close_output` and `cargo_command::closed_output_ok` do not fail which would fail if cargo was built with `-Zon-broken-pipe=kill`.
## Related discussions
Thanks to everyone who helped!
- https://rust-lang.zulipchat.com/#narrow/stream/246057-t-cargo/topic/Applying.20.60-Zon-broken-pipe.3Dkill.60.20flags.20in.20bootstrap.3F
- https://rust-lang.zulipchat.com/#narrow/stream/326414-t-infra.2Fbootstrap/topic/Modifying.20run-make.20tests.20unnecessarily.20rebuild.20stage.201.20.2E.2E.2E
- https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Internal.20lint.20for.20raw.20.60print!.60.20and.20.60println!.60.3F
Fixes https://github.com/rust-lang/rust/issues/130980
Closes https://github.com/rust-lang/rust/issues/131059
---
try-job: aarch64-apple
try-job: x86_64-msvc
try-job: x86_64-mingw
Simplify the compiletest directives for ignoring coverage-test modes
Follow-up to #131346.
Given that these directives are now restricted to ignoring coverage-test modes only, we can drop the clunky `ignore-mode-*` naming convention, and just call them `ignore-coverage-map` and `ignore-coverage-run`.
r? jieyouxu
use precompiled rustc for non-dist builders
Makes non-dist builders to use precompiled CI rustc by default if they are available for the target triple.
As we are going to make `rust.download-rustc=if-unchanged` default option with https://github.com/rust-lang/rust/pull/119899, we need to make sure `if-unchanged` logic never breaks and works as expected.
As an addition, this will significantly improve the build times on CI when there's no change on the compiler.
blocker for #119899
try-job: x86_64-gnu-nopt
try-job: aarch64-apple
Drop compiletest legacy directive check
Sufficient time has passed (> 6 months) since we migrated from `//` to `//`@`,` so let's drop the
legacy directive check as it causes friction due to false positives.
As a side-effect, dropping the legacy directive check simplifies the directive scanning logic.
The legacy directive check was originally added to help people be aware of the migration.
Blocker for #131382 cc `@ehuss.`
Can be reviewed by any compiler/bootstrap reviewer.
[rustdoc] Remove intra-doc links dead code
While working on https://github.com/rust-lang/rust/pull/130278, I wondered what `resolve_display_text` was doing. I removed it and ran all rustdoc tests, and nothing failed. Are some intra-doc links tests missing or is it really dead code? Couldn't figure it out.
r? `@notriddle`
Sufficient time has passed (> 6 months) since we migrated from `//` to
`//@`, so let's drop the legacy directive check as it causes friction
due to false positives.
[Coverage][MCDC] Adapt mcdc to llvm 19
Related issue: #126672
Also finish task 4 at #124144
[llvm #82448](https://github.com/llvm/llvm-project/pull/82448) has introduced some break changes into mcdc, causing incompatibility between llvm 18 and 19. This draft adapts to that change and gives up supporting for llvm-18.
`Deref`/`DerefMut` can be useful, but they can also obfuscate. I don't
think they're worth it for `RegionConstraintCollector`. They're also not
present on the similar types `OpaqueTypeTable` and `TypeVariableTable`.
`LeakCheck` can own `mini_graph` and `rcc` instead of holding references
to them. This requires inlining `assign_scc_value` to avoid a borrowck
error, but that's fine because it has a single call site.
