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When bootstrapping Rust, the `-j N` flag was passed to CMake, which was then forwarded to Ninja. This prevents the jobserver from being used, and as a result leads to oversubscription when Rust is just one of the many packages built as part of a larger software stack. Since Cargo and the Rust compiler have long supported the jobserver, it would be good if also bootstrapping Rust itself would participate in the protocol, leading to composable parallelism. This change allows bootstrapping to respect an existing FIFO based jobserver. Old pipe based jobservers are not supported, because they are brittle: currently the Python scripts in bootstrap do not inherit the file descriptors, but do pass on `MAKEFLAGS`. Because Ninja only supports FIFO based jobservers, it's better to focus on new jobservers only. In summary: * Bootstrap Cargo passes `MAKEFLAGS` verbatim to subprocesses if it advertises a FIFO style jobserver, otherwise it unsets it. * `llvm.rs` does not pass `-j` to `cmake` when a FIFO style jobserver is set in `MAKEFLAGS. * Bootstrap Cargo no longer unsets `MKFLAGS`: from git blame, GNU Make considered it a historical artifact back in 1992, and it is never read by GNU Make, it's only set for backwards compatibility. Signed-off-by: Harmen Stoppels <me@harmenstoppels.nl>
And `install src` with `build.docs = false`.
As far as I can tell it was introduced to allow fat LTO with -Clinker-plugin-lto. Later a change was made to automatically disable ThinLTO summary generation when -Clinker-plugin-lto -Clto=fat is used, so we can safely remove it.
`use _` is never valid, so it should not be suggested as a similar name.
Rather than "an"
…observer-protocol, r=clubby789 bootstrap: respect POSIX jobserver When bootstrapping Rust, the `-j N` flag was passed to CMake, which was then forwarded to Ninja. This prevents the jobserver from being used, and as a result leads to oversubscription when Rust is just one of the many packages built as part of a larger software stack. Since Cargo and the Rust compiler have long supported the jobserver, it would be good if also bootstrapping Rust itself would participate in the protocol, leading to composable parallelism. This change allows bootstrapping to respect an existing FIFO based jobserver. Old pipe based jobservers are not supported, because they are brittle: currently the Python scripts in bootstrap do not inherit the file descriptors, but do pass on `MAKEFLAGS`, which has lead to errors like "invalid file descriptor" in the past. Because Ninja only supports FIFO based jobservers, it's better to focus on new jobservers only, which shouldn't suffer from the "invalid file descriptor" issue. In summary: * Bootstrap Cargo passes `MAKEFLAGS` verbatim to subprocesses if it advertises a FIFO style jobserver, otherwise it unsets it. This ensures subprocesses respect the jobserver during bootstrap. * `llvm.rs` does not pass `-j` to `cmake` when a FIFO style jobserver is set in `MAKEFLAGS`. This ensures Ninja respects the jobserver. * Bootstrap Cargo no longer unsets `MKFLAGS`: from git blame, GNU Make considered it a historical artifact back in 1992, and it is never read by GNU Make, it's only set for backwards compatibility in case sub-Makefiles read it. --- I've tested this with the [Spack package manager](https://github.com/spack/spack) starting the POSIX jobserver, building node.js and rust in parallel with `-j16`, which looks like this: ```console $ pstree 382710 python3─┬─python3 └─python3─┬─python3─┬─make───make───6*[ccache───g++───cc1plus] │ └─{python3} └─python3─┬─python3.11───bootstrap───cmake───ninja-build───10*[sh───ccache───g++───cc1plus] └─{python3} ``` As you can see there are 10 `g++` processes running for rust, and `6` for node.js, and with a mix of `make` and `ninja` as build tools :). (The only violation I see now is `rust-lld`, but I think that'll be fixed with the LLVM 23 release)
…uviper Remove -Zemit-thin-lto flag As far as I can tell it was introduced in rust-lang#98162 to allow fat LTO with `-Clinker-plugin-lto`. In rust-lang#136840 a change was made to automatically disable ThinLTO summary generation when `-Clinker-plugin-lto -Clto=fat` is used, so we can safely remove it. Fixes rust-lang#152490
DOC: do not link to "nightly" in Iterator::by_ref() docstring I happened to see that the link in the docstring https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.by_ref points to the "nightly" docs instead of "stable". I'm not sure if my fix actually works because I didn't get `cargo doc` to run on my local computer.
…docs, r=clubby789
Add bootstrap snapshot tests for {`install`, `install src`}
And `install src` with `build.docs = false`.
This is mostly to get coverage for the baseline to make it easier to review rust-lang#150845.
…ercote Clarify some variable names in the query proc-macro These are some cleanups to the `rustc_macros::query`, extracted from rust-lang#152833. r? nnethercote
Fix typo in doc for core::mem::type_info::Struct
…ort-suggestion, r=Kivooeo resolve: do not suggest `_` for unresolved imports Fix invalid unresolved-import suggestion when a module contains an item named `_`. `use _` is never valid syntax, so `_` should not be suggested as a similar name. Closes rust-lang#152812
std::ops::ControlFlow - use "a" before `Result` Rather than "an"
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Rollup of 8 pull requests Successful merges: - #152057 (bootstrap: respect POSIX jobserver) - #152527 (Remove -Zemit-thin-lto flag) - #152818 (DOC: do not link to "nightly" in Iterator::by_ref() docstring) - #152840 (Add bootstrap snapshot tests for {`install`, `install src`}) - #152846 (Clarify some variable names in the query proc-macro) - #152858 (Fix typo in doc for core::mem::type_info::Struct) - #152861 (resolve: do not suggest `_` for unresolved imports) - #152873 (std::ops::ControlFlow - use "a" before `Result`)
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💔 Test for 60279ab failed: CI. Failed job:
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PR #152527, which is a member of this rollup, was unapproved. |
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Successful merges:
install,install src} #152840 (Add bootstrap snapshot tests for {install,install src})_for unresolved imports #152861 (resolve: do not suggest_for unresolved imports)Result#152873 (std::ops::ControlFlow - use "a" beforeResult)r? @ghost
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