Enable ThinLTO for rustc on `x86_64-apple-darwin`
Local measurements seemed to show an improvement on a couple benchmarks, so I'd like to test real CI builds, and see if the builder doesn't timeout with the expected slight increase in build times.
Let's start with x64 rustc ThinLTO, and then figure out the file structure to configure LLVM ThinLTO. Maybe we'll then try `aarch64` builds since that also looked good locally.
Enable ThinLTO for rustc on x64 msvc
This applies the great work from `@bjorn3` and `@Kobzol` in https://github.com/rust-lang/rust/pull/101403 to x64 msvc.
Here are the local results for the try build `68c5c85ed759334a11f0b0e586f5032a23f85ce4`, compared to its parent `0a6b941df354c59b546ec4c0d27f2b9b0cb1162c`. Looking better than my previous local builds.
(I can't show cycle counts, as that option is failing on the windows version of the perf collector, but I'll try to analyze and debug this soon)
This will be the first of a few tests for rustc / llvm / both ThinLTO on the windows and mac targets.
Don't internalize __llvm_profile_counter_bias
Currently, LLVM profiling runtime counter relocation cannot be used by rust during LTO because symbols are being internalized before all symbol information is known.
This mode makes LLVM emit a __llvm_profile_counter_bias symbol which is referenced by the profiling initialization, which itself is pulled in by the rust driver here [1].
It is enabled with -Cllvm-args=-runtime-counter-relocation for platforms which are opt-in to this mode like Linux. On these platforms there will be no link error, rather just surprising behavior for a user which request runtime counter relocation. The profiling runtime will not see that symbol go on as if it were never there. On Fuchsia, the profiling runtime must have this symbol which will cause a hard link error.
As an aside, I don't have enough context as to why rust's LTO model is how it is. AFAICT, the internalize pass is only safe to run at link time when all symbol information is actually known, this being an example as to why. I think special casing this symbol as a known one that LLVM can emit which should not have it's visbility de-escalated should be fine given how seldom this pattern of defining an undefined symbol to get initilization code pulled in is. From a quick grep, __llvm_profile_runtime is the only symbol that rustc does this for.
[1] 0265a3e93b/compiler/rustc_codegen_ssa/src/back/linker.rs (L598)
rustdoc: Only hide lines starting with `#` in rust code blocks
Fixes https://github.com/rust-lang/rust/issues/105527.
So before approving, this is a big question: in rust code blocks, in a line starts with a `#`, we hide it in the output. However, should we do the same for non-rust code blocks too? I think it's a bit problematic to do it because `#` can be used for many things but I prefer to check first with everyone (might also be worth updating documentation too).
cc ``@rust-lang/rustdoc``
r? ``@notriddle``
compiler: remove unnecessary imports and qualified paths
Some of these imports were necessary before Edition 2021, others were already in the prelude.
I hope it's fine that this PR is so spread-out across files :/
rustdoc: Prevent auto/blanket impl retrieval if there were compiler errors
Fixes https://github.com/rust-lang/rust/issues/105404.
I'm not sure happy about this fix but since it's how passes work (ie, even if there are errors, it runs all passes), I think it's fine as is.
Just as a sidenote: I also gave a try to prevent running all passes in case there were compiler errors but then a lot of rustdoc tests were failing so I went for this fix instead.
r? `@notriddle`
Some method confirmation code nits
1. Make some pick methods take `&self` instead of `&mut` to avoid some cloning
2. Pass some values by reference to avoid some cloning
3. Rename a few variables here and there
Fix invalid codegen during debuginfo lowering
In order for LLVM to correctly generate debuginfo for msvc, we sometimes need to spill arguments to the stack and perform some direct & indirect offsets into the value. Previously, this code always performed those actions, even when not required as LLVM would clean it up during optimization.
However, when MIR inlining is enabled, this can cause problems as the operations occur prior to the spilled value being initialized. To solve this, we first calculate the necessary offsets using just the type which is side-effect free and does not alter the LLVM IR. Then, if we are in a situation which requires us to generate the LLVM IR (and this situation only occurs for arguments, not local variables) then we perform the same calculation again, this time generating the appropriate LLVM IR as we go.
r? `@tmiasko` but feel free to reassign if you want 🙂Fixes#105386
Avoid heap allocation when truncating thread names
Ensure that heap allocation does not occur in a thread until `std::thread` is ready. This fixes issues with custom allocators that call `std:🧵:current()`, since doing so prematurely initializes `THREAD_INFO` and causes the following `thread_info::set()` to fail.
Migrate parts of `rustc_expand` to session diagnostics
This migrates everything but the `mbe` and `proc_macro` modules. It also contains a few cleanups and drive-by/accidental diagnostic improvements which can be seen in the diff for the UI tests.
Fix failing codegen tests on s390x
Several codegen tests are currently failing due to making assumptions that are not valid for the s390x architecture:
- catch-unwind.rs: fails due to inlining differences. Already ignored on another platform for the same reason. Solution: Ignore on s390x.
- remap_path_prefix/main.rs: fails due to different alignment requirement for string constants. Solution: Do not test for the alignment requirement.
- repr-transparent-aggregates-1.rs: many ABI assumptions. Already ignored on many platforms for the same reason. Solution: Ignore on s390x.
- repr-transparent.rs: no vector ABI by default on s390x. Already ignored on another platform for a similar reason. Solution: Ignore on s390x.
- uninit-consts.rs: hard-coded little-endian constant. Solution: Match both little- and big-endian versions.
Fixes part of https://github.com/rust-lang/rust/issues/105383.
Rollup of 10 pull requests
Successful merges:
- #98391 (Reimplement std's thread parker on top of events on SGX)
- #104019 (Compute generator sizes with `-Zprint_type_sizes`)
- #104512 (Set `download-ci-llvm = "if-available"` by default when `channel = dev`)
- #104901 (Implement masking in FileType comparison on Unix)
- #105082 (Fix Async Generator ABI)
- #105109 (Add LLVM KCFI support to the Rust compiler)
- #105505 (Don't warn about unused parens when they are used by yeet expr)
- #105514 (Introduce `Span::is_visible`)
- #105516 (Update cargo)
- #105522 (Remove wrong note for short circuiting operators)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
This migrates everything but the `mbe` and `proc_macro` modules. It also
contains a few cleanups and drive-by/accidental diagnostic improvements
which can be seen in the diff for the UI tests.
Remove wrong note for short circuiting operators
They *are* representable by traits, even if the short-circuiting behaviour requires a different approach than the non-short-circuiting operators. For an example proposal, see the postponed [RFC 2722](https://github.com/rust-lang/rfcs/pull/2722). As it is not accurate, remove most of the note.
Add LLVM KCFI support to the Rust compiler
This PR adds LLVM Kernel Control Flow Integrity (KCFI) support to the Rust compiler. It initially provides forward-edge control flow protection for operating systems kernels for Rust-compiled code only by aggregating function pointers in groups identified by their return and parameter types. (See llvm/llvm-project@cff5bef.)
Forward-edge control flow protection for C or C++ and Rust -compiled code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code share the same virtual address space) will be provided in later work as part of this project by identifying C char and integer type uses at the time types are encoded (see Type metadata in the design document in the tracking issue #89653).
LLVM KCFI can be enabled with -Zsanitizer=kcfi.
Thank you again, `@bjorn3,` `@eddyb,` `@nagisa,` and `@ojeda,` for all the help!
Fix Async Generator ABI
This change was missed when making async generators implement `Future` directly.
It did not cause any problems in codegen so far, as `GeneratorState<(), Output>`
happens to have the same ABI as `Poll<Output>`.
Set `download-ci-llvm = "if-available"` by default when `channel = dev`
See https://github.com/rust-lang/compiler-team/issues/566. The motivation for changing the default is to avoid downloading and building LLVM when someone runs `x build` before running `x setup`. The motivation for only doing it on `channel = "dev"` is to avoid breaking distros or users installing from source. It works because `dev` is also the default channel.
The diff looks larger than it is; most of it is moving the `llvm` branch below the `rust` so `config.channel` is set.
r? `@Mark-Simulacrum` cc `@oli-obk` `@bjorn3` `@cuviper`
