Avoid lowering code under dead SwitchInt targets
The objective of this PR is to detect and eliminate code which is guarded by an `if false`, even if that `false` is a constant which is not known until monomorphization, or is `intrinsics::debug_assertions()`.
The effect of this is that we generate no LLVM IR the standard library's unsafe preconditions, when they are compiled in a build where they should be immediately optimized out. This mono-time optimization ensures that builds which disable debug assertions do not grow a linkage requirement against `core`, which compiler-builtins currently needs: https://github.com/rust-lang/rust/issues/121552
This revives the codegen side of https://github.com/rust-lang/rust/pull/91222 as planned in https://github.com/rust-lang/rust/issues/120848.
Verify that query keys result in unique dep nodes
This implements checking that query keys result into unique dep nodes as mentioned in https://github.com/rust-lang/rust/pull/112469.
We could do a perf check to see how expensive this is.
r? `@michaelwoerister`
Only generate a ptrtoint in AtomicPtr codegen when absolutely necessary
This special case was added in this PR: https://github.com/rust-lang/rust/pull/77611 in response to this error message:
```
Intrinsic has incorrect argument type!
void ({}*)* `@llvm.ppc.cfence.p0sl_s`
in function rust_oom
LLVM ERROR: Broken function found, compilation aborted!
[RUSTC-TIMING] std test:false 20.161
error: could not compile `std`
```
But when I tried searching for more information about that intrinsic I found this: https://github.com/llvm/llvm-project/issues/55983 which is a report of someone hitting this same error and a fix was landed in LLVM, 2 years after the above Rust PR.
Update cargo
9 commits in a4c63fe5388beaa09e5f91196c86addab0a03580..7065f0ef4aa267a7455e1c478b5ccacb7baea59c
2024-03-06 22:15:17 +0000 to 2024-03-12 13:25:15 +0000
- chore: remove repetitive word (rust-lang/cargo#13575)
- refactor(lockfile): Make diffing/printing more reusable (rust-lang/cargo#13564)
- test: Add tests for using worktrees and sparse checkouts (rust-lang/cargo#13567)
- util/network/http: Use `cargo/1.2.3` user-agent header (rust-lang/cargo#13548)
- fix: Consistently compare MSRVs (rust-lang/cargo#13537)
- refactor(shell): Use alternate to close links (rust-lang/cargo#13562)
- fix(doc): Collapse down Generated statuses without --verbose (rust-lang/cargo#13557)
- doc: Add doc for -Zpublic-dependency (rust-lang/cargo#13556)
- docs: add link to the exported_private_dependencies lint (rust-lang/cargo#13547)
r? ghost
Properly rebuild rustbooks
Fixes#122367
If the book was out of date but the tool was up to date, this would evaluate to `!(false || true)` == `!true` == `false` and not rebuild.
rustdoc: fix up old test
`tests/rustdoc/line-breaks.rs` had several issues:
1. It used `//`@count`` instead of `// `@count`` (notice the space!) which gets treated as a `ui_test` directive instead of a `htmldocck` one. `compiletest` didn't flag it as an error because it's allowlisted ([#121561](https://github.com/rust-lang/rust/pull/121561)) presumably precisely because of this test. And before the compiletest→ui_test migration, these directives must've been ignored, too, because …
2. … the checks themselves no longer work either: The count of `<br>`s is actually 0 in all 3 cases because – well – we no longer generate any `<br>`s inside `<pre>`s.
Since I don't know how to ``@count`` `\n`s instead of `<br>`s, I've turned them into ``@matches`.` Btw, I don't know if this test is still desirable or if we have other tests that cover this (I haven't checked).
r? rustdoc
bootstrap: Don't eagerly format verbose messages
We `format!` a lot of messages which are only used when we are at some level of verbosity - do this lazily instead
Add tests for the generated assembly of mask related simd instructions.
The tests show that the code generation currently uses the least significant bits of <iX x N> vector masks when converting to <i1 xN>. This leads to an additional left shift operation in the assembly for x86, since mask operations on x86 operate based on the most significant bit.
The exception is simd_bitmask, which already uses the most-significant bit.
This additional instruction would be removed by the changes in #104693, which makes all mask operations consistently use the most significant bits.
By using the "C" calling convention the tests should be stable regarding changes in register allocation, but it is possible that future llvm updates will require updating some of the checks.
[bootstrap] Move the `split-debuginfo` setting to the per-target section
As described in #112406, bootstrap currently applies the global `split-debuginfo` setting to all artifacts, irrespective of their target triple.
This doesn't cause problems when the "build" triple defaults `split-debuginfo` to `off` (as is the case on Linux, for example).
However, when the "build" triple has `split-debuginfo` enabled and additional target triples are configured, then artifacts for the additional triples will also be built with `split-debuginfo` (despite not necessarily supporting `split-debuginfo`).
#112406 mentions `riscv32imc-unknown-none-elf` as one target where this happens, and I've run into this with Wasm as well.
This PR does **not** implement `@ehuss's` suggestion that "bootstrap not try to guess how to configure split-debuginfo, and instead use cargo profiles to set it", because that seemed like a lot more significant change.
---
After this PR, anyone explicitly setting `rust.split-debuginfo` should update their configuration to specify the setting in the `target.<triple>` section, though `rust.split-debuginfo` will still be honored for the "build" triple for now.
This PR changes the behavior when `rust.split-debuginfo` was **not** explicitly set **and** bootstrap is configured to cross-compile to a triple that has a different `split-debuginfo` than the "build" triple.
---
If there's a reasonable way to add additional tests for this, please let me know (I didn't find any tests checking cargo arguments in [`builder/tests.rs`](https://github.com/rust-lang/rust/blob/master/src/bootstrap/src/core/builder/tests.rs)).
Ensure nested allocations in statics neither get deduplicated nor duplicated
This PR generates new `DefId`s for nested allocations in static items and feeds all the right queries to make the compiler believe these are regular `static` items. I chose this design, because all other designs are fragile and make the compiler horribly complex for such a niche use case.
At present this wrecks incremental compilation performance *in case nested allocations exist* (because any query creating a `DefId` will be recomputed and never loaded from the cache). This will be resolved later in https://github.com/rust-lang/rust/pull/115613 . All other statics are unaffected by this change and will not have performance regressions (heh, famous last words)
This PR contains various smaller refactorings that can be pulled out into separate PRs. It is best reviewed commit-by-commit. The last commit is where the actual magic happens.
r? `@RalfJung` on the const interner and engine changes
fixes https://github.com/rust-lang/rust/issues/79738
Rename `wasm32-wasi-preview1-threads` to `wasm32-wasip1-threads`
This commit renames the current `wasm32-wasi-preview1-threads` target to `wasm32-wasip1-threads`. The need for this rename is a bit unfortunate as the previous name was chosen in an attempt to be future-compatible with other WASI targets. Originally this target was proposed to be `wasm32-wasi-threads`, and that's what was originally implemented in wasi-sdk as well. After discussion though and with the plans for the upcoming component-model target (now named `wasm32-wasip2`) the "preview1" naming was chosen for the threads-based target. The WASI subgroup later decided that it was time to drop the "preview" terminology and recommends "pX" instead, hence previous PRs to add `wasm32-wasip2` and rename `wasm32-wasi` to `wasm32-wasip1`.
So, with all that history, the "proper name" for this target is different than its current name, so one way or another a rename is required. This PR proposes renaming this target cold-turkey, unlike `wasm32-wasi` which is having a long transition period to change its name. The threads-based target is predicted to see only a fraction of the traffic of `wasm32-wasi` due to the unstable nature of the WASI threads proposal itself.
While I was here I updated the in-tree documentation in the target spec file itself as most of the documentation was copied from the original WASI target and wasn't as applicable to this target.
Also, as an aside, I can at least try to apologize for all the naming confusion here, but this is hopefully the last WASI-related rename.
The tests show that the code generation currently uses the least
significant bits of <iX x N> vector masks when converting to <i1 xN>.
This leads to an additional left shift operation in the assembly for
x86, since mask operations on x86 operate based on the most significant
bit. On aarch64 the left shift is followed by a comparison against zero,
which repeats the sign bit across the whole lane.
The exception, which does not introduce an unneeded shift, is
simd_bitmask, because the code generation already shifts before
truncating.
By using the "C" calling convention the tests should be stable regarding
changes in register allocation, but it is possible that future llvm
updates will require updating some of the checks.
This additional instruction would be removed by the fix in #104693,
which uses the most significant bit for all mask operations.
Rollup of 8 pull requests
Successful merges:
- #115141 (Update Windows platform support)
- #121865 (Add FileCheck annotations to MIR-opt unnamed-fields tests)
- #122000 (Fix 32-bit overflows in LLVM composite constants)
- #122194 (Enable creating backtraces via -Ztreat-err-as-bug when stashing errors)
- #122319 (Don't ICE when non-self part of trait goal is constrained in new solver)
- #122339 (Update books)
- #122342 (Update /NODEFAUTLIB comment for msvc)
- #122343 (Remove some unnecessary `allow(incomplete_features)` in the test suite)
r? `@ghost`
`@rustbot` modify labels: rollup
Update /NODEFAUTLIB comment for msvc
I've tried to explain a bit more about the effects of `/NODEFAULTLIB` when using msvc link.exe (or compatible) as they're different from `-nodefaultlib` on gnu.
I also removed the part about licensing as I'm not sure licensing is an issue? Or rather, it's no more or less of an issue no matter how you link msvc libraries. The license is the one you get if using VS at all and even dynamic linking includes static code (e.g. startup/shutdown code, etc).
r? petrochenkov
Enable creating backtraces via -Ztreat-err-as-bug when stashing errors
r? `@nnethercote`
Otherwise I can't debug stashed errors because I can't find their source
