rust/clippy_lints/src/ref_option_ref.rs
xFrednet d647696c1f
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 -.-
2021-11-10 19:48:31 +01:00

72 lines
2.4 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::last_path_segment;
use clippy_utils::source::snippet;
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{GenericArg, Mutability, Ty, TyKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::symbol::sym;
declare_clippy_lint! {
/// ### What it does
/// Checks for usage of `&Option<&T>`.
///
/// ### Why is this bad?
/// Since `&` is Copy, it's useless to have a
/// reference on `Option<&T>`.
///
/// ### Known problems
/// It may be irrelevant to use this lint on
/// public API code as it will make a breaking change to apply it.
///
/// ### Example
/// ```rust,ignore
/// let x: &Option<&u32> = &Some(&0u32);
/// ```
/// Use instead:
/// ```rust,ignore
/// let x: Option<&u32> = Some(&0u32);
/// ```
#[clippy::version = "1.49.0"]
pub REF_OPTION_REF,
pedantic,
"use `Option<&T>` instead of `&Option<&T>`"
}
declare_lint_pass!(RefOptionRef => [REF_OPTION_REF]);
impl<'tcx> LateLintPass<'tcx> for RefOptionRef {
fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
if_chain! {
if let TyKind::Rptr(_, ref mut_ty) = ty.kind;
if mut_ty.mutbl == Mutability::Not;
if let TyKind::Path(ref qpath) = &mut_ty.ty.kind;
let last = last_path_segment(qpath);
if let Some(res) = last.res;
if let Some(def_id) = res.opt_def_id();
if cx.tcx.is_diagnostic_item(sym::Option, def_id);
if let Some(params) = last_path_segment(qpath).args ;
if !params.parenthesized;
if let Some(inner_ty) = params.args.iter().find_map(|arg| match arg {
GenericArg::Type(inner_ty) => Some(inner_ty),
_ => None,
});
if let TyKind::Rptr(_, _) = inner_ty.kind;
then {
span_lint_and_sugg(
cx,
REF_OPTION_REF,
ty.span,
"since `&` implements the `Copy` trait, `&Option<&T>` can be simplified to `Option<&T>`",
"try",
format!("Option<{}>", &snippet(cx, inner_ty.span, "..")),
Applicability::MaybeIncorrect,
);
}
}
}
}