2021-03-16 00:55:45 +00:00
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use clippy_utils::diagnostics::span_lint_and_then;
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2021-03-14 23:17:44 +00:00
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use clippy_utils::source::snippet_with_applicability;
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2018-11-27 20:14:15 +00:00
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use if_chain::if_chain;
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2018-12-29 15:04:45 +00:00
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use rustc_errors::Applicability;
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2020-01-06 16:39:50 +00:00
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use rustc_hir::{BindingAnnotation, Mutability, Node, Pat, PatKind};
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2020-01-12 06:08:41 +00:00
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use rustc_lint::{LateContext, LateLintPass};
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2020-01-11 11:37:08 +00:00
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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2017-06-24 10:04:56 +00:00
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2021-07-02 18:37:11 +00:00
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/// ### What it does
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/// Checks for bindings that destructure a reference and borrow the inner
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2021-02-26 01:51:49 +00:00
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/// value with `&ref`.
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2019-03-05 16:50:33 +00:00
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///
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2021-07-02 18:37:11 +00:00
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/// ### Why is this bad?
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/// This pattern has no effect in almost all cases.
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2019-03-05 16:50:33 +00:00
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///
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2021-07-02 18:37:11 +00:00
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/// ### Known problems
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/// In some cases, `&ref` is needed to avoid a lifetime mismatch error.
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2021-02-26 01:51:49 +00:00
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/// Example:
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/// ```rust
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/// fn foo(a: &Option<String>, b: &Option<String>) {
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2019-03-05 16:50:33 +00:00
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/// match (a, b) {
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2021-02-26 01:51:49 +00:00
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/// (None, &ref c) | (&ref c, None) => (),
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/// (&Some(ref c), _) => (),
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/// };
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2019-03-05 16:50:33 +00:00
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/// }
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/// ```
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///
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2021-07-02 18:37:11 +00:00
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/// ### Example
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2019-03-05 16:50:33 +00:00
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/// ```rust
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/// let mut v = Vec::<String>::new();
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2022-06-07 00:28:16 +00:00
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/// # #[allow(unused)]
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2022-06-05 19:24:41 +00:00
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/// v.iter_mut().filter(|&ref a| a.is_empty());
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2019-03-05 16:50:33 +00:00
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/// ```
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2021-02-26 01:51:49 +00:00
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///
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2022-06-05 19:24:41 +00:00
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/// Use instead:
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2021-02-26 01:51:49 +00:00
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/// ```rust
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/// let mut v = Vec::<String>::new();
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2022-06-07 00:28:16 +00:00
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/// # #[allow(unused)]
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2022-06-05 19:24:41 +00:00
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/// v.iter_mut().filter(|a| a.is_empty());
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2021-02-26 01:51:49 +00:00
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/// ```
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Added `clippy::version` attribute to all normal lints
So, some context for this, well, more a story. I'm not used to scripting, I've never really scripted anything, even if it's a valuable skill. I just never really needed it. Now, `@flip1995` correctly suggested using a script for this in `rust-clippy#7813`...
And I decided to write a script using nushell because why not? This was a mistake... I spend way more time on this than I would like to admit. It has definitely been more than 4 hours. It shouldn't take that long, but me being new to scripting and nushell just wasn't a good mixture... Anyway, here is the script that creates another script which adds the versions. Fun...
Just execute this on the `gh-pages` branch and the resulting `replacer.sh` in `clippy_lints` and it should all work.
```nu
mv v0.0.212 rust-1.00.0;
mv beta rust-1.57.0;
mv master rust-1.58.0;
let paths = (open ./rust-1.58.0/lints.json | select id id_span | flatten | select id path);
let versions = (
ls | where name =~ "rust-" | select name | format {name}/lints.json |
each { open $it | select id | insert version $it | str substring "5,11" version} |
group-by id | rotate counter-clockwise id version |
update version {get version | first 1} | flatten | select id version);
$paths | each { |row|
let version = ($versions | where id == ($row.id) | format {version})
let idu = ($row.id | str upcase)
$"sed -i '0,/($idu),/{s/pub ($idu),/#[clippy::version = "($version)"]\n pub ($idu),/}' ($row.path)"
} | str collect ";" | str find-replace --all '1.00.0' 'pre 1.29.0' | save "replacer.sh";
```
And this still has some problems, but at this point I just want to be done -.-
2021-10-21 19:06:26 +00:00
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#[clippy::version = "pre 1.29.0"]
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2017-06-24 10:04:56 +00:00
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pub NEEDLESS_BORROWED_REFERENCE,
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2018-03-28 13:24:26 +00:00
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complexity,
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2021-02-26 01:51:49 +00:00
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"destructuring a reference and borrowing the inner value"
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2017-06-24 10:04:56 +00:00
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}
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2019-04-08 20:43:55 +00:00
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declare_lint_pass!(NeedlessBorrowedRef => [NEEDLESS_BORROWED_REFERENCE]);
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2017-06-24 10:04:56 +00:00
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2020-06-25 20:41:36 +00:00
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impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowedRef {
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fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
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2019-08-19 16:30:32 +00:00
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if pat.span.from_expansion() {
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2017-06-24 10:04:56 +00:00
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// OK, simple enough, lints doesn't check in macro.
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return;
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}
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2017-10-23 19:18:02 +00:00
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if_chain! {
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2017-06-29 11:45:54 +00:00
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// Only lint immutable refs, because `&mut ref T` may be useful.
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2021-04-02 21:35:32 +00:00
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if let PatKind::Ref(sub_pat, Mutability::Not) = pat.kind;
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2017-07-01 10:01:39 +00:00
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2017-07-01 14:56:19 +00:00
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// Check sub_pat got a `ref` keyword (excluding `ref mut`).
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2019-09-27 15:16:06 +00:00
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if let PatKind::Binding(BindingAnnotation::Ref, .., spanned_name, _) = sub_pat.kind;
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2019-09-25 12:19:09 +00:00
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let parent_id = cx.tcx.hir().get_parent_node(pat.hir_id);
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if let Some(parent_node) = cx.tcx.hir().find(parent_id);
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2017-10-23 19:18:02 +00:00
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then {
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2019-09-25 12:19:09 +00:00
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// do not recurse within patterns, as they may have other references
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// XXXManishearth we can relax this constraint if we only check patterns
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// with a single ref pattern inside them
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if let Node::Pat(_) = parent_node {
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return;
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}
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let mut applicability = Applicability::MachineApplicable;
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2017-10-23 19:18:02 +00:00
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span_lint_and_then(cx, NEEDLESS_BORROWED_REFERENCE, pat.span,
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"this pattern takes a reference on something that is being de-referenced",
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2020-04-17 06:08:00 +00:00
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|diag| {
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2019-09-25 12:19:09 +00:00
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let hint = snippet_with_applicability(cx, spanned_name.span, "..", &mut applicability).into_owned();
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2020-04-17 06:08:00 +00:00
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diag.span_suggestion(
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2018-11-27 20:14:15 +00:00
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pat.span,
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2018-09-18 15:07:54 +00:00
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"try removing the `&ref` part and just keep",
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hint,
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2019-09-25 12:19:09 +00:00
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applicability,
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2018-09-18 15:07:54 +00:00
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);
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2017-10-23 19:18:02 +00:00
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});
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}
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}
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2017-06-24 10:04:56 +00:00
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}
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}
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