rust/clippy_lints/src/attrs/useless_attribute.rs
2024-12-26 15:15:54 +01:00

90 lines
4 KiB
Rust

use super::USELESS_ATTRIBUTE;
use super::utils::{is_lint_level, is_word, namespace_and_lint};
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::source::{SpanRangeExt, first_line_of_span};
use rustc_ast::{Attribute, Item, ItemKind};
use rustc_errors::Applicability;
use rustc_lint::{EarlyContext, LintContext};
use rustc_middle::lint::in_external_macro;
use rustc_span::sym;
pub(super) fn check(cx: &EarlyContext<'_>, item: &Item, attrs: &[Attribute]) {
let skip_unused_imports = attrs.iter().any(|attr| attr.has_name(sym::macro_use));
for attr in attrs {
if in_external_macro(cx.sess(), attr.span) {
return;
}
if let Some(lint_list) = &attr.meta_item_list() {
if attr.ident().is_some_and(|ident| is_lint_level(ident.name, attr.id)) {
for lint in lint_list {
match item.kind {
ItemKind::Use(..) => {
let (namespace @ (Some(sym::clippy) | None), Some(name)) = namespace_and_lint(lint) else {
return;
};
if namespace.is_none()
&& matches!(
name.as_str(),
"ambiguous_glob_reexports"
| "dead_code"
| "deprecated"
| "hidden_glob_reexports"
| "unreachable_pub"
| "unused"
| "unused_braces"
| "unused_import_braces"
| "unused_imports"
)
{
return;
}
if namespace == Some(sym::clippy)
&& matches!(
name.as_str(),
"wildcard_imports"
| "enum_glob_use"
| "redundant_pub_crate"
| "macro_use_imports"
| "unsafe_removed_from_name"
| "module_name_repetitions"
| "single_component_path_imports"
| "disallowed_types"
| "unused_trait_names"
)
{
return;
}
},
ItemKind::ExternCrate(..) => {
if is_word(lint, sym::unused_imports) && skip_unused_imports {
return;
}
if is_word(lint, sym!(unused_extern_crates)) {
return;
}
},
_ => {},
}
}
let line_span = first_line_of_span(cx, attr.span);
if let Some(src) = line_span.get_source_text(cx) {
if src.contains("#[") {
#[expect(clippy::collapsible_span_lint_calls)]
span_lint_and_then(cx, USELESS_ATTRIBUTE, line_span, "useless lint attribute", |diag| {
diag.span_suggestion(
line_span,
"if you just forgot a `!`, use",
src.replacen("#[", "#![", 1),
Applicability::MaybeIncorrect,
);
});
}
}
}
}
}
}