76 lines
2.7 KiB
Rust
76 lines
2.7 KiB
Rust
use clippy_utils::{
|
|
diagnostics::{span_lint, span_lint_hir_and_then},
|
|
path_res,
|
|
ty::implements_trait,
|
|
};
|
|
use rustc_hir::{def_id::DefId, Item, ItemKind, Node};
|
|
use rustc_hir_analysis::hir_ty_to_ty;
|
|
use rustc_lint::{LateContext, LateLintPass};
|
|
use rustc_session::{declare_lint_pass, declare_tool_lint};
|
|
use rustc_span::sym;
|
|
|
|
declare_clippy_lint! {
|
|
/// ### What it does
|
|
/// Checks for types named `Error` that implement `Error`.
|
|
///
|
|
/// ### Why is this bad?
|
|
/// It can become confusing when a codebase has 20 types all named `Error`, requiring either
|
|
/// aliasing them in the `use` statement them or qualifying them like `my_module::Error`. This
|
|
/// severely hinders readability.
|
|
///
|
|
/// ### Example
|
|
/// ```rust,ignore
|
|
/// #[derive(Debug)]
|
|
/// pub enum Error { ... }
|
|
///
|
|
/// impl std::fmt::Display for Error { ... }
|
|
///
|
|
/// impl std::error::Error for Error { ... }
|
|
/// ```
|
|
#[clippy::version = "1.72.0"]
|
|
pub ERROR_IMPL_ERROR,
|
|
restriction,
|
|
"types named `Error` that implement `Error`"
|
|
}
|
|
declare_lint_pass!(ErrorImplError => [ERROR_IMPL_ERROR]);
|
|
|
|
impl<'tcx> LateLintPass<'tcx> for ErrorImplError {
|
|
fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
|
|
let Some(error_def_id) = cx.tcx.get_diagnostic_item(sym::Error) else {
|
|
return;
|
|
};
|
|
|
|
match item.kind {
|
|
ItemKind::TyAlias(ty, _) if implements_trait(cx, hir_ty_to_ty(cx.tcx, ty), error_def_id, &[])
|
|
&& item.ident.name == sym::Error =>
|
|
{
|
|
span_lint(
|
|
cx,
|
|
ERROR_IMPL_ERROR,
|
|
item.ident.span,
|
|
"type alias named `Error` that implements `Error`",
|
|
);
|
|
},
|
|
ItemKind::Impl(imp) if let Some(trait_def_id) = imp.of_trait.and_then(|t| t.trait_def_id())
|
|
&& error_def_id == trait_def_id
|
|
&& let Some(def_id) = path_res(cx, imp.self_ty).opt_def_id().and_then(DefId::as_local)
|
|
&& let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def_id)
|
|
&& let Node::Item(ty_item) = cx.tcx.hir().get(hir_id)
|
|
&& ty_item.ident.name == sym::Error =>
|
|
{
|
|
span_lint_hir_and_then(
|
|
cx,
|
|
ERROR_IMPL_ERROR,
|
|
hir_id,
|
|
ty_item.ident.span,
|
|
"type named `Error` that implements `Error`",
|
|
|diag| {
|
|
diag.span_note(item.span, "`Error` was implemented here");
|
|
}
|
|
);
|
|
}
|
|
_ => {},
|
|
}
|
|
{}
|
|
}
|
|
}
|