Show that Command can be reused and remodified
The prior documentation did not make it clear this was possible.
I wanted to make the `list_dir` example work on Windows, but I don't know if passing "/" will error or show the root of the current volume (e.g. `C:`).
r? @GuillaumeGomez
A few cleanups for rustc_data_structures
- remove a redundant `clone()`
- make some calls to `.iter()` implicit
- collapse/simplify a few operations
- remove some explicit `return`s
- make `SnapshotMap::{commit, rollback_to}` take references
- remove unnecessary struct field names
- change `transmute()`s in `IdxSet::{from_slice, from_slice_mut}` to casts
- remove some unnecessary lifetime annotations
- split 2 long literals
Consider changing assert! to debug_assert! when it calls visit_with
The perf run from #52956 revealed that there were 3 benchmarks that benefited most from changing `assert!`s to `debug_assert!`s:
- issue #46449: avg -4.7% for -check
- deeply-nested (AKA #38528): avg -3.4% for -check
- regression #31157: avg -3.2% for -check
I analyzed their fixing PRs and decided to look for potentially heavy assertions in the files they modified. I noticed that all of the non-trivial ones contained indirect calls to `visit_with()`.
It might be a good idea to consider changing `assert!` to `debug_assert!` in those places in order to get the performance wins shown by the benchmarks.
Don't collect() when size_hint is useless
This adjusts PRs #52738 and #52697 by falling back to calculating capacity and extending or pushing in a loop where `collect()` can't be trusted to calculate the right capacity.
It is a performance win.
Update compiler test documentation
Update the compiler test documentation to document ignore-gdb-version
and min-system-llvm-version; and expand the min-gdb-version,
min-lldb-version, and min-llvm-version documentation a little.
The error and check for this already existed, but the parser didn't try to parse trait method arguments as patterns, so the error was never emitted. This surfaces the error, so we get better errors than simple parse errors.
There are a few places where we mention the replacement character in the
docs, and it could be helpful for users to utilize the constant which is
available in the standard library, so let’s link to it!
optimize redundant borrows and escaping paths in NLL
This builds on https://github.com/rust-lang/rust/pull/53168 and adds a commit that addresses https://github.com/rust-lang/rust/issues/53176 -- or at least I think it does. I marked this as WIP because I want to see the test results (and measure the performance). I also want to double check we're not adding in any unsoundness here.
As explained by eddyb in #53221, "An &ArchiveChild doesn't point into the archive itself, it points to an owned object that itself points to the archive, and LLVMRustArchiveMemberNew copies the ArchiveChild (whereas the current signature suggests it keeps the &ArchiveChild)."
