Rollup of 6 pull requests
Successful merges:
- #74088 (Avoid writes without any data in `Write::write_all_vectored`)
- #74598 (Fix sync_once_cell_does_not_leak_partially_constructed_boxes)
- #74750 (Clean up some uses of logging in ui tests)
- #74783 (python codes cleanup)
- #74790 (Don't italicize comments in ayu theme)
- #74799 (Fixed typo in `closure`)
Failed merges:
r? @ghost
Clean up some uses of logging in ui tests
The removed test can't possibly trigger anything today as we don't have logging in libstd.
The `exec-env` flag was mistakenly used for adding env vars to rustc invocations both in test and in the test suite and there were some accidental renames from RUST_LOG to RUSTC_LOG that I reverted.
Fix sync_once_cell_does_not_leak_partially_constructed_boxes
Spinning multiple threads in this test causes a deadlock in
SGX where thread scheduling is not preemptive.
cc @jethrogb @AdrianCX
Avoid writes without any data in `Write::write_all_vectored`
Previously, when non-empty sequence of empty IoSlices have been provided
to `Write::write_all_vectored`, the buffers would be written as is with
`Write::write_vectored` and subsequently the return value `Ok(0)` would
be misinterpreted as an error.
Avoid writes without any data by advancing the buffers first. This
matches the documented behaviour of `Write::write_all_vectored`
and is analogous to what happens in `Write::write_all`.
Pull out some duplicated code into a new function
I debated pulling the actual struct_span_err calls into the new method, but I felt like having to pass in multiple arguments for it and wiring up string formatting outweighed the benefits.
Viewing the diff with whitespace ignored is recommended.
proc_macro: Add API for tracked access to environment variables
Continuation of https://github.com/rust-lang/rust/pull/71858.
`proc_macro::tracked_env::var` is similar to regular `env::var` called from a proc macro, except that it also adds the accessed variable to depinfo.
Serialize span hygiene data
Fixes#68686Fixes#70963
This PR serializies global hygiene data into both the incremental compilation cache and the crate metadata. This allows hygiene information to be preserved across compilation sessions (both incremental and cross-crate).
When serializing a `SyntaxContext`, we simply write out the raw id from the current compilation session. Whenever we deserialize a `SyntaxContext`, we 'remap' the id to a fresh id in our current compilation session, and load the associated `SyntaxContextData`.
As a result, some 'upstream' `SyntaxContextData` will end up getting duplicated in 'downstream' crates. This only happens when we actually need to use an 'upstream' `SyntaxContext`, which occurs when we deserialize a `Span` that requires it.
We serialize an `ExpnData` into the metadata of the crate which generated it. An `ExpnId` is serialized as a reference into the crate which 'owns' the corresponding `ExpnData`, which avoids duplication in downstream crates.
I've included a macros 2.0 test which requires hygiene serialization to compile successfully.
TODO:
- [x] <strike>Determine how many additional `DefId`s we end up creating for `ExpnId`s - this may be significant for `libcore`, which uses macros heavily. Alternatively, we could try to compute a `DefPathHash` without making a corresponding `DefId` - however, this might significantly complicate the implementation.</strike> (We no longer create `DefId`s)
- [x] Investigate the overhead of duplicating `SyntaxContextData` in crate metadata.
- [x] Investigate how `resolve_crate_root` behaves with deserialized hygiene data - the current logic may be wrong.
- [x] Add additional tests. The effects of this PR are usually only noticeable when working with headache-inducing macro expansions (e.g. macros expanding to macros), so there are lots of corner cases to test.
- [x] Determine what to do about this:
4774f9b523/src/librustc_resolve/build_reduced_graph.rs (L892)
- [x] Determine if we need to do anything here - I think the fact that `src/test/ui/hygiene/cross_crate_hygiene.rs` passes means that this is working.
3d5d0f898c/src/librustc_resolve/imports.rs (L1389-L1392)
A raw SyntaxContext id is implicitly dependent on the target platform,
since libstd and libcore have platform-dependent #[cfg]s which affect
which macros are invoked. As a result, we must strip out any
SyntaxContext ids from test output to ensure that the captured stdout is
not platform-dependent.
