Less `TokenTree` cloning
`TokenTreeCursor` has this comment on it:
```
// FIXME: Many uses of this can be replaced with by-reference iterator to avoid clones.
```
This PR completes that FIXME. It doesn't have much perf effect, but at least we now know that.
r? `@petrochenkov`
Resolves 5542
Prior to rust-lang/rust#101212 the `ast::TraitObjectSyntax` enum only
had two variants `Dyn` and `None`. The PR that introduced the `dyn*`
syntax added a new variant `DynStar`, but did not update the formatting
rules to account for the new variant.
Now the new `DynStar` variant is properly handled and is no longer
removed by rustfmt.
Currently, Clippy, Miri, Rustfmt, and rustc all use an environment variable to
indicate that output should be blessed, but they use different variable names.
In order to improve consistency, this patch applies the following changes:
- Emit `RUSTC_BLESS` within `prepare_cargo_test` so it is always
available
- Change usage of `MIRI_BLESS` in the Miri subtree to use `RUSTC_BLESS`
- Change usage of `BLESS` in the Clippy subtree to `RUSTC_BLESS`
- Change usage of `BLESS` in the Rustfmt subtree to `RUSTC_BLESS`
- Adjust the blessable test in `rustc_errors` to use this same
convention
- Update documentation where applicable
Any tools that uses `RUSTC_BLESS` should check that it is set to any value
other than `"0"`.
Update docs to include an example of running `rustfmt` built from src,
and show how users can set the `RUSTFMT` environment variable to test
`cargo-fmt` using the `rustfmt` they built from src.
Implement rust-lang/compiler-team#578.
When an ICE is encountered on nightly releases, the new rustc panic
handler will also write the contents of the backtrace to disk. If any
`delay_span_bug`s are encountered, their backtrace is also added to the
file. The platform and rustc version will also be collected.
Fixes 5730
Previously rustfmt was attempting to slice a string with an invalid
range (`start > end`), leading to the ICE.
When formatting a macro transcriber snippet consisting of a lone
semicolon, the snippet was being formatted into the empty string,
leading the enclosing `fn main() {\n}` added by `format_code_block` to
be formatted into `fn main() {}`. However, rustfmt was assuming that the
enclosing function string's length had been left unchanged. This was
leading to an invalid range being constructed when attempting to trim
off the enclosing function.
The fix is to just clamp the range's start to be less than or equal
to the range's end, since if `end < start` there's nothing to iterate
over anyway.
* Use matches!() macro to improve readability
1. Use `matches!()` macro in `is_line_comment` and `is_block_comment` to
improve readability.
2. Very sightly improve the wording of the doc comment for these two functions.
* Update wording on doc comment on is_line_comment()
There was an issue with the script when passing optional rustfmt configs
without specifying a commit hash. Because these optional values are
passed via positional arguments the configs ($4) would be used in place
of the commit hash ($3). Now that we set a default value for the
optional commit hash we avoid this problem.
The `set -e` option is used to immediately exit if any command exits
with a non zero exit status. This will help us catch errors in the
script, for example, needing the `LD_LIBRARY_PATH` to be set.
There were some upstream changes made a while back that requires this to
be set when building rustfmt from source like we do in the
`check_diff.sh` script.
See issue 5675 for more details.
By reversing the logic I felt that the code became a clearer. Also,
added a comment to make it clear that we need to take the trailing
semicolon for the `let-else` statement into account.
This allows users to configure the maximum length of a single line
`let-else` statements. `let-else` statements that otherwise meet the
requirements to be formatted on a single line will have their divergent
`else` block formatted over multiple lines if they exceed this length.
**Note**: `single_line_let_else_max_widt` will be introduced as a stable
configuration option.
Syntactically accept `become` expressions (explicit tail calls experiment)
This adds `ast::ExprKind::Become`, implements parsing and properly gates the feature.
cc `@scottmcm`
These test cases try to cover various edge cases. For example, comments
around the else keyword and long, unbreakable, single-line initializer
expressions, and long patterns.
`rewrite_let_else_block` gives us more control over allowing the `else`
block to be formatted on a single line than
`<ast::Block as Rewrite>::rewrite`.
This will make it easier to format the divergent blocks of `let-else`
statements since it'll be easier to prevent the block from being
formatted on a single line if the preconditions aren't met.
The function properly handles recovering comments before and after the
`else` keyword, and properly handles how to write the else when users
configure `control_brace_style`.
