diff --git a/clippy_lints/src/attrs.rs b/clippy_lints/src/attrs.rs deleted file mode 100644 index 5d74c3e62034d..0000000000000 --- a/clippy_lints/src/attrs.rs +++ /dev/null @@ -1,1265 +0,0 @@ -//! checks for attributes - -use clippy_config::msrvs::{self, Msrv}; -use clippy_utils::diagnostics::{ - span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then, -}; -use clippy_utils::is_from_proc_macro; -use clippy_utils::macros::{is_panic, macro_backtrace}; -use clippy_utils::source::{first_line_of_span, is_present_in_source, snippet_opt, without_block_comments}; -use rustc_ast::token::{Token, TokenKind}; -use rustc_ast::tokenstream::TokenTree; -use rustc_ast::{ - AttrArgs, AttrArgsEq, AttrId, AttrKind, AttrStyle, Attribute, LitKind, MetaItemKind, MetaItemLit, NestedMetaItem, -}; -use rustc_errors::Applicability; -use rustc_hir::{ - Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind, -}; -use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, Level, LintContext}; -use rustc_middle::lint::in_external_macro; -use rustc_middle::ty; -use rustc_session::{declare_lint_pass, impl_lint_pass}; -use rustc_span::symbol::Symbol; -use rustc_span::{sym, Span, DUMMY_SP}; -use semver::Version; - -static UNIX_SYSTEMS: &[&str] = &[ - "android", - "dragonfly", - "emscripten", - "freebsd", - "fuchsia", - "haiku", - "illumos", - "ios", - "l4re", - "linux", - "macos", - "netbsd", - "openbsd", - "redox", - "solaris", - "vxworks", -]; - -// NOTE: windows is excluded from the list because it's also a valid target family. -static NON_UNIX_SYSTEMS: &[&str] = &["hermit", "none", "wasi"]; - -declare_clippy_lint! { - /// ### What it does - /// Checks for items annotated with `#[inline(always)]`, - /// unless the annotated function is empty or simply panics. - /// - /// ### Why is this bad? - /// While there are valid uses of this annotation (and once - /// you know when to use it, by all means `allow` this lint), it's a common - /// newbie-mistake to pepper one's code with it. - /// - /// As a rule of thumb, before slapping `#[inline(always)]` on a function, - /// measure if that additional function call really affects your runtime profile - /// sufficiently to make up for the increase in compile time. - /// - /// ### Known problems - /// False positives, big time. This lint is meant to be - /// deactivated by everyone doing serious performance work. This means having - /// done the measurement. - /// - /// ### Example - /// ```ignore - /// #[inline(always)] - /// fn not_quite_hot_code(..) { ... } - /// ``` - #[clippy::version = "pre 1.29.0"] - pub INLINE_ALWAYS, - pedantic, - "use of `#[inline(always)]`" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `extern crate` and `use` items annotated with - /// lint attributes. - /// - /// This lint permits lint attributes for lints emitted on the items themself. - /// For `use` items these lints are: - /// * deprecated - /// * unreachable_pub - /// * unused_imports - /// * clippy::enum_glob_use - /// * clippy::macro_use_imports - /// * clippy::wildcard_imports - /// - /// For `extern crate` items these lints are: - /// * `unused_imports` on items with `#[macro_use]` - /// - /// ### Why is this bad? - /// Lint attributes have no effect on crate imports. Most - /// likely a `!` was forgotten. - /// - /// ### Example - /// ```ignore - /// #[deny(dead_code)] - /// extern crate foo; - /// #[forbid(dead_code)] - /// use foo::bar; - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// #[allow(unused_imports)] - /// use foo::baz; - /// #[allow(unused_imports)] - /// #[macro_use] - /// extern crate baz; - /// ``` - #[clippy::version = "pre 1.29.0"] - pub USELESS_ATTRIBUTE, - correctness, - "use of lint attributes on `extern crate` items" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `#[deprecated]` annotations with a `since` - /// field that is not a valid semantic version. Also allows "TBD" to signal - /// future deprecation. - /// - /// ### Why is this bad? - /// For checking the version of the deprecation, it must be - /// a valid semver. Failing that, the contained information is useless. - /// - /// ### Example - /// ```no_run - /// #[deprecated(since = "forever")] - /// fn something_else() { /* ... */ } - /// ``` - #[clippy::version = "pre 1.29.0"] - pub DEPRECATED_SEMVER, - correctness, - "use of `#[deprecated(since = \"x\")]` where x is not semver" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for empty lines after outer attributes - /// - /// ### Why is this bad? - /// Most likely the attribute was meant to be an inner attribute using a '!'. - /// If it was meant to be an outer attribute, then the following item - /// should not be separated by empty lines. - /// - /// ### Known problems - /// Can cause false positives. - /// - /// From the clippy side it's difficult to detect empty lines between an attributes and the - /// following item because empty lines and comments are not part of the AST. The parsing - /// currently works for basic cases but is not perfect. - /// - /// ### Example - /// ```no_run - /// #[allow(dead_code)] - /// - /// fn not_quite_good_code() { } - /// ``` - /// - /// Use instead: - /// ```no_run - /// // Good (as inner attribute) - /// #![allow(dead_code)] - /// - /// fn this_is_fine() { } - /// - /// // or - /// - /// // Good (as outer attribute) - /// #[allow(dead_code)] - /// fn this_is_fine_too() { } - /// ``` - #[clippy::version = "pre 1.29.0"] - pub EMPTY_LINE_AFTER_OUTER_ATTR, - nursery, - "empty line after outer attribute" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for empty lines after documentation comments. - /// - /// ### Why is this bad? - /// The documentation comment was most likely meant to be an inner attribute or regular comment. - /// If it was intended to be a documentation comment, then the empty line should be removed to - /// be more idiomatic. - /// - /// ### Known problems - /// Only detects empty lines immediately following the documentation. If the doc comment is followed - /// by an attribute and then an empty line, this lint will not trigger. Use `empty_line_after_outer_attr` - /// in combination with this lint to detect both cases. - /// - /// Does not detect empty lines after doc attributes (e.g. `#[doc = ""]`). - /// - /// ### Example - /// ```no_run - /// /// Some doc comment with a blank line after it. - /// - /// fn not_quite_good_code() { } - /// ``` - /// - /// Use instead: - /// ```no_run - /// /// Good (no blank line) - /// fn this_is_fine() { } - /// ``` - /// - /// ```no_run - /// // Good (convert to a regular comment) - /// - /// fn this_is_fine_too() { } - /// ``` - /// - /// ```no_run - /// //! Good (convert to a comment on an inner attribute) - /// - /// fn this_is_fine_as_well() { } - /// ``` - #[clippy::version = "1.70.0"] - pub EMPTY_LINE_AFTER_DOC_COMMENTS, - nursery, - "empty line after documentation comments" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category. - /// - /// ### Why is this bad? - /// Restriction lints sometimes are in contrast with other lints or even go against idiomatic rust. - /// These lints should only be enabled on a lint-by-lint basis and with careful consideration. - /// - /// ### Example - /// ```no_run - /// #![deny(clippy::restriction)] - /// ``` - /// - /// Use instead: - /// ```no_run - /// #![deny(clippy::as_conversions)] - /// ``` - #[clippy::version = "1.47.0"] - pub BLANKET_CLIPPY_RESTRICTION_LINTS, - suspicious, - "enabling the complete restriction group" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it - /// with `#[rustfmt::skip]`. - /// - /// ### Why is this bad? - /// Since tool_attributes ([rust-lang/rust#44690](https://github.com/rust-lang/rust/issues/44690)) - /// are stable now, they should be used instead of the old `cfg_attr(rustfmt)` attributes. - /// - /// ### Known problems - /// This lint doesn't detect crate level inner attributes, because they get - /// processed before the PreExpansionPass lints get executed. See - /// [#3123](https://github.com/rust-lang/rust-clippy/pull/3123#issuecomment-422321765) - /// - /// ### Example - /// ```no_run - /// #[cfg_attr(rustfmt, rustfmt_skip)] - /// fn main() { } - /// ``` - /// - /// Use instead: - /// ```no_run - /// #[rustfmt::skip] - /// fn main() { } - /// ``` - #[clippy::version = "1.32.0"] - pub DEPRECATED_CFG_ATTR, - complexity, - "usage of `cfg_attr(rustfmt)` instead of tool attributes" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for cfg attributes having operating systems used in target family position. - /// - /// ### Why is this bad? - /// The configuration option will not be recognised and the related item will not be included - /// by the conditional compilation engine. - /// - /// ### Example - /// ```no_run - /// #[cfg(linux)] - /// fn conditional() { } - /// ``` - /// - /// Use instead: - /// ```no_run - /// # mod hidden { - /// #[cfg(target_os = "linux")] - /// fn conditional() { } - /// # } - /// - /// // or - /// - /// #[cfg(unix)] - /// fn conditional() { } - /// ``` - /// Check the [Rust Reference](https://doc.rust-lang.org/reference/conditional-compilation.html#target_os) for more details. - #[clippy::version = "1.45.0"] - pub MISMATCHED_TARGET_OS, - correctness, - "usage of `cfg(operating_system)` instead of `cfg(target_os = \"operating_system\")`" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for attributes that allow lints without a reason. - /// - /// (This requires the `lint_reasons` feature) - /// - /// ### Why is this bad? - /// Allowing a lint should always have a reason. This reason should be documented to - /// ensure that others understand the reasoning - /// - /// ### Example - /// ```no_run - /// #![feature(lint_reasons)] - /// - /// #![allow(clippy::some_lint)] - /// ``` - /// - /// Use instead: - /// ```no_run - /// #![feature(lint_reasons)] - /// - /// #![allow(clippy::some_lint, reason = "False positive rust-lang/rust-clippy#1002020")] - /// ``` - #[clippy::version = "1.61.0"] - pub ALLOW_ATTRIBUTES_WITHOUT_REASON, - restriction, - "ensures that all `allow` and `expect` attributes have a reason" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `#[should_panic]` attributes without specifying the expected panic message. - /// - /// ### Why is this bad? - /// The expected panic message should be specified to ensure that the test is actually - /// panicking with the expected message, and not another unrelated panic. - /// - /// ### Example - /// ```no_run - /// fn random() -> i32 { 0 } - /// - /// #[should_panic] - /// #[test] - /// fn my_test() { - /// let _ = 1 / random(); - /// } - /// ``` - /// - /// Use instead: - /// ```no_run - /// fn random() -> i32 { 0 } - /// - /// #[should_panic = "attempt to divide by zero"] - /// #[test] - /// fn my_test() { - /// let _ = 1 / random(); - /// } - /// ``` - #[clippy::version = "1.74.0"] - pub SHOULD_PANIC_WITHOUT_EXPECT, - pedantic, - "ensures that all `should_panic` attributes specify its expected panic message" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `any` and `all` combinators in `cfg` with only one condition. - /// - /// ### Why is this bad? - /// If there is only one condition, no need to wrap it into `any` or `all` combinators. - /// - /// ### Example - /// ```no_run - /// #[cfg(any(unix))] - /// pub struct Bar; - /// ``` - /// - /// Use instead: - /// ```no_run - /// #[cfg(unix)] - /// pub struct Bar; - /// ``` - #[clippy::version = "1.71.0"] - pub NON_MINIMAL_CFG, - style, - "ensure that all `cfg(any())` and `cfg(all())` have more than one condition" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `#[cfg(features = "...")]` and suggests to replace it with - /// `#[cfg(feature = "...")]`. - /// - /// It also checks if `cfg(test)` was misspelled. - /// - /// ### Why is this bad? - /// Misspelling `feature` as `features` or `test` as `tests` can be sometimes hard to spot. It - /// may cause conditional compilation not work quietly. - /// - /// ### Example - /// ```no_run - /// #[cfg(features = "some-feature")] - /// fn conditional() { } - /// #[cfg(tests)] - /// mod tests { } - /// ``` - /// - /// Use instead: - /// ```no_run - /// #[cfg(feature = "some-feature")] - /// fn conditional() { } - /// #[cfg(test)] - /// mod tests { } - /// ``` - #[clippy::version = "1.69.0"] - pub MAYBE_MISUSED_CFG, - suspicious, - "prevent from misusing the wrong attr name" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `#[cfg_attr(feature = "cargo-clippy", ...)]` and for - /// `#[cfg(feature = "cargo-clippy")]` and suggests to replace it with - /// `#[cfg_attr(clippy, ...)]` or `#[cfg(clippy)]`. - /// - /// ### Why is this bad? - /// This feature has been deprecated for years and shouldn't be used anymore. - /// - /// ### Example - /// ```no_run - /// #[cfg(feature = "cargo-clippy")] - /// struct Bar; - /// ``` - /// - /// Use instead: - /// ```no_run - /// #[cfg(clippy)] - /// struct Bar; - /// ``` - #[clippy::version = "1.78.0"] - pub DEPRECATED_CLIPPY_CFG_ATTR, - suspicious, - "usage of `cfg(feature = \"cargo-clippy\")` instead of `cfg(clippy)`" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for `#[cfg_attr(clippy, allow(clippy::lint))]` - /// and suggests to replace it with `#[allow(clippy::lint)]`. - /// - /// ### Why is this bad? - /// There is no reason to put clippy attributes behind a clippy `cfg` as they are not - /// run by anything else than clippy. - /// - /// ### Example - /// ```no_run - /// #![cfg_attr(clippy, allow(clippy::deprecated_cfg_attr))] - /// ``` - /// - /// Use instead: - /// ```no_run - /// #![allow(clippy::deprecated_cfg_attr)] - /// ``` - #[clippy::version = "1.78.0"] - pub UNNECESSARY_CLIPPY_CFG, - suspicious, - "usage of `cfg_attr(clippy, allow(clippy::lint))` instead of `allow(clippy::lint)`" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks that an item has only one kind of attributes. - /// - /// ### Why is this bad? - /// Having both kinds of attributes makes it more complicated to read code. - /// - /// ### Example - /// ```no_run - /// #[cfg(linux)] - /// pub fn foo() { - /// #![cfg(windows)] - /// } - /// ``` - /// Use instead: - /// ```no_run - /// #[cfg(linux)] - /// #[cfg(windows)] - /// pub fn foo() { - /// } - /// ``` - #[clippy::version = "1.78.0"] - pub MIXED_ATTRIBUTES_STYLE, - suspicious, - "item has both inner and outer attributes" -} - -declare_lint_pass!(Attributes => [ - ALLOW_ATTRIBUTES_WITHOUT_REASON, - INLINE_ALWAYS, - DEPRECATED_SEMVER, - USELESS_ATTRIBUTE, - BLANKET_CLIPPY_RESTRICTION_LINTS, - SHOULD_PANIC_WITHOUT_EXPECT, -]); - -impl<'tcx> LateLintPass<'tcx> for Attributes { - fn check_crate(&mut self, cx: &LateContext<'tcx>) { - for (name, level) in &cx.sess().opts.lint_opts { - if name == "clippy::restriction" && *level > Level::Allow { - span_lint_and_then( - cx, - BLANKET_CLIPPY_RESTRICTION_LINTS, - DUMMY_SP, - "`clippy::restriction` is not meant to be enabled as a group", - |diag| { - diag.note(format!( - "because of the command line `--{} clippy::restriction`", - level.as_str() - )); - diag.help("enable the restriction lints you need individually"); - }, - ); - } - } - } - - fn check_attribute(&mut self, cx: &LateContext<'tcx>, attr: &'tcx Attribute) { - if let Some(items) = &attr.meta_item_list() { - if let Some(ident) = attr.ident() { - if is_lint_level(ident.name, attr.id) { - check_clippy_lint_names(cx, ident.name, items); - } - if matches!(ident.name, sym::allow | sym::expect) { - check_lint_reason(cx, ident.name, items, attr); - } - if items.is_empty() || !attr.has_name(sym::deprecated) { - return; - } - for item in items { - if let NestedMetaItem::MetaItem(mi) = &item - && let MetaItemKind::NameValue(lit) = &mi.kind - && mi.has_name(sym::since) - { - check_deprecated_since(cx, item.span(), lit); - } - } - } - } - if attr.has_name(sym::should_panic) { - check_should_panic_reason(cx, attr); - } - } - - fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) { - let attrs = cx.tcx.hir().attrs(item.hir_id()); - if is_relevant_item(cx, item) { - check_attrs(cx, item.span, item.ident.name, attrs); - } - match item.kind { - ItemKind::ExternCrate(..) | ItemKind::Use(..) => { - 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().map_or(false, |ident| is_lint_level(ident.name, attr.id)) { - for lint in lint_list { - match item.kind { - ItemKind::Use(..) => { - if is_word(lint, sym::unused_imports) - || is_word(lint, sym::deprecated) - || is_word(lint, sym!(unreachable_pub)) - || is_word(lint, sym!(unused)) - || is_word(lint, sym!(unused_import_braces)) - || extract_clippy_lint(lint).map_or(false, |s| { - matches!( - s.as_str(), - "wildcard_imports" - | "enum_glob_use" - | "redundant_pub_crate" - | "macro_use_imports" - | "unsafe_removed_from_name" - | "module_name_repetitions" - | "single_component_path_imports" - ) - }) - { - 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(mut sugg) = snippet_opt(cx, line_span) { - if sugg.contains("#[") { - span_lint_and_then( - cx, - USELESS_ATTRIBUTE, - line_span, - "useless lint attribute", - |diag| { - sugg = sugg.replacen("#[", "#![", 1); - diag.span_suggestion( - line_span, - "if you just forgot a `!`, use", - sugg, - Applicability::MaybeIncorrect, - ); - }, - ); - } - } - } - } - } - }, - _ => {}, - } - } - - fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) { - if is_relevant_impl(cx, item) { - check_attrs(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id())); - } - } - - fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) { - if is_relevant_trait(cx, item) { - check_attrs(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id())); - } - } -} - -/// Returns the lint name if it is clippy lint. -fn extract_clippy_lint(lint: &NestedMetaItem) -> Option { - if let Some(meta_item) = lint.meta_item() - && meta_item.path.segments.len() > 1 - && let tool_name = meta_item.path.segments[0].ident - && tool_name.name == sym::clippy - { - let lint_name = meta_item.path.segments.last().unwrap().ident.name; - return Some(lint_name); - } - None -} - -fn check_should_panic_reason(cx: &LateContext<'_>, attr: &Attribute) { - if let AttrKind::Normal(normal_attr) = &attr.kind { - if let AttrArgs::Eq(_, AttrArgsEq::Hir(_)) = &normal_attr.item.args { - // `#[should_panic = ".."]` found, good - return; - } - - if let AttrArgs::Delimited(args) = &normal_attr.item.args - && let mut tt_iter = args.tokens.trees() - && let Some(TokenTree::Token( - Token { - kind: TokenKind::Ident(sym::expected, _), - .. - }, - _, - )) = tt_iter.next() - && let Some(TokenTree::Token( - Token { - kind: TokenKind::Eq, .. - }, - _, - )) = tt_iter.next() - && let Some(TokenTree::Token( - Token { - kind: TokenKind::Literal(_), - .. - }, - _, - )) = tt_iter.next() - { - // `#[should_panic(expected = "..")]` found, good - return; - } - - span_lint_and_sugg( - cx, - SHOULD_PANIC_WITHOUT_EXPECT, - attr.span, - "#[should_panic] attribute without a reason", - "consider specifying the expected panic", - "#[should_panic(expected = /* panic message */)]".into(), - Applicability::HasPlaceholders, - ); - } -} - -fn check_clippy_lint_names(cx: &LateContext<'_>, name: Symbol, items: &[NestedMetaItem]) { - for lint in items { - if let Some(lint_name) = extract_clippy_lint(lint) { - if lint_name.as_str() == "restriction" && name != sym::allow { - span_lint_and_help( - cx, - BLANKET_CLIPPY_RESTRICTION_LINTS, - lint.span(), - "`clippy::restriction` is not meant to be enabled as a group", - None, - "enable the restriction lints you need individually", - ); - } - } - } -} - -fn check_lint_reason<'cx>(cx: &LateContext<'cx>, name: Symbol, items: &[NestedMetaItem], attr: &'cx Attribute) { - // Check for the feature - if !cx.tcx.features().lint_reasons { - return; - } - - // Check if the reason is present - if let Some(item) = items.last().and_then(NestedMetaItem::meta_item) - && let MetaItemKind::NameValue(_) = &item.kind - && item.path == sym::reason - { - return; - } - - // Check if the attribute is in an external macro and therefore out of the developer's control - if in_external_macro(cx.sess(), attr.span) || is_from_proc_macro(cx, &attr) { - return; - } - - span_lint_and_help( - cx, - ALLOW_ATTRIBUTES_WITHOUT_REASON, - attr.span, - &format!("`{}` attribute without specifying a reason", name.as_str()), - None, - "try adding a reason at the end with `, reason = \"..\"`", - ); -} - -fn is_relevant_item(cx: &LateContext<'_>, item: &Item<'_>) -> bool { - if let ItemKind::Fn(_, _, eid) = item.kind { - is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value) - } else { - true - } -} - -fn is_relevant_impl(cx: &LateContext<'_>, item: &ImplItem<'_>) -> bool { - match item.kind { - ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value), - _ => false, - } -} - -fn is_relevant_trait(cx: &LateContext<'_>, item: &TraitItem<'_>) -> bool { - match item.kind { - TraitItemKind::Fn(_, TraitFn::Required(_)) => true, - TraitItemKind::Fn(_, TraitFn::Provided(eid)) => { - is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value) - }, - _ => false, - } -} - -fn is_relevant_block(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, block: &Block<'_>) -> bool { - block.stmts.first().map_or( - block - .expr - .as_ref() - .map_or(false, |e| is_relevant_expr(cx, typeck_results, e)), - |stmt| match &stmt.kind { - StmtKind::Local(_) => true, - StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, typeck_results, expr), - StmtKind::Item(_) => false, - }, - ) -} - -fn is_relevant_expr(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, expr: &Expr<'_>) -> bool { - if macro_backtrace(expr.span).last().map_or(false, |macro_call| { - is_panic(cx, macro_call.def_id) || cx.tcx.item_name(macro_call.def_id) == sym::unreachable - }) { - return false; - } - match &expr.kind { - ExprKind::Block(block, _) => is_relevant_block(cx, typeck_results, block), - ExprKind::Ret(Some(e)) => is_relevant_expr(cx, typeck_results, e), - ExprKind::Ret(None) | ExprKind::Break(_, None) => false, - _ => true, - } -} - -fn check_attrs(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribute]) { - if span.from_expansion() { - return; - } - - for attr in attrs { - if let Some(values) = attr.meta_item_list() { - if values.len() != 1 || !attr.has_name(sym::inline) { - continue; - } - if is_word(&values[0], sym::always) { - span_lint( - cx, - INLINE_ALWAYS, - attr.span, - &format!("you have declared `#[inline(always)]` on `{name}`. This is usually a bad idea"), - ); - } - } - } -} - -fn check_deprecated_since(cx: &LateContext<'_>, span: Span, lit: &MetaItemLit) { - if let LitKind::Str(is, _) = lit.kind { - if is.as_str() == "TBD" || Version::parse(is.as_str()).is_ok() { - return; - } - } - span_lint( - cx, - DEPRECATED_SEMVER, - span, - "the since field must contain a semver-compliant version", - ); -} - -fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool { - if let NestedMetaItem::MetaItem(mi) = &nmi { - mi.is_word() && mi.has_name(expected) - } else { - false - } -} - -pub struct EarlyAttributes { - pub msrv: Msrv, -} - -impl_lint_pass!(EarlyAttributes => [ - DEPRECATED_CFG_ATTR, - MISMATCHED_TARGET_OS, - EMPTY_LINE_AFTER_OUTER_ATTR, - EMPTY_LINE_AFTER_DOC_COMMENTS, - NON_MINIMAL_CFG, - MAYBE_MISUSED_CFG, - DEPRECATED_CLIPPY_CFG_ATTR, - UNNECESSARY_CLIPPY_CFG, - MIXED_ATTRIBUTES_STYLE, -]); - -impl EarlyLintPass for EarlyAttributes { - fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) { - check_empty_line_after_outer_attr(cx, item); - check_mixed_attributes(cx, item); - } - - fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) { - check_deprecated_cfg_attr(cx, attr, &self.msrv); - check_deprecated_cfg(cx, attr); - check_mismatched_target_os(cx, attr); - check_minimal_cfg_condition(cx, attr); - check_misused_cfg(cx, attr); - } - - extract_msrv_attr!(EarlyContext); -} - -fn check_mixed_attributes(cx: &EarlyContext<'_>, item: &rustc_ast::Item) { - let mut has_outer = false; - let mut has_inner = false; - - for attr in &item.attrs { - if attr.span.from_expansion() { - continue; - } - match attr.style { - AttrStyle::Inner => has_inner = true, - AttrStyle::Outer => has_outer = true, - } - } - if !has_outer || !has_inner { - return; - } - let mut attrs_iter = item.attrs.iter().filter(|attr| !attr.span.from_expansion()); - let span = attrs_iter.next().unwrap().span; - span_lint( - cx, - MIXED_ATTRIBUTES_STYLE, - span.with_hi(attrs_iter.last().unwrap().span.hi()), - "item has both inner and outer attributes", - ); -} - -/// Check for empty lines after outer attributes. -/// -/// Attributes and documentation comments are both considered outer attributes -/// by the AST. However, the average user likely considers them to be different. -/// Checking for empty lines after each of these attributes is split into two different -/// lints but can share the same logic. -fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::Item) { - let mut iter = item.attrs.iter().peekable(); - while let Some(attr) = iter.next() { - if (matches!(attr.kind, AttrKind::Normal(..)) || matches!(attr.kind, AttrKind::DocComment(..))) - && attr.style == AttrStyle::Outer - && is_present_in_source(cx, attr.span) - { - let begin_of_attr_to_item = Span::new(attr.span.lo(), item.span.lo(), item.span.ctxt(), item.span.parent()); - let end_of_attr_to_next_attr_or_item = Span::new( - attr.span.hi(), - iter.peek().map_or(item.span.lo(), |next_attr| next_attr.span.lo()), - item.span.ctxt(), - item.span.parent(), - ); - - if let Some(snippet) = snippet_opt(cx, end_of_attr_to_next_attr_or_item) { - let lines = snippet.split('\n').collect::>(); - let lines = without_block_comments(lines); - - if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 { - let (lint_msg, lint_type) = match attr.kind { - AttrKind::DocComment(..) => ( - "found an empty line after a doc comment. \ - Perhaps you need to use `//!` to make a comment on a module, remove the empty line, or make a regular comment with `//`?", - EMPTY_LINE_AFTER_DOC_COMMENTS, - ), - AttrKind::Normal(..) => ( - "found an empty line after an outer attribute. \ - Perhaps you forgot to add a `!` to make it an inner attribute?", - EMPTY_LINE_AFTER_OUTER_ATTR, - ), - }; - - span_lint(cx, lint_type, begin_of_attr_to_item, lint_msg); - } - } - } - } -} - -fn check_cargo_clippy_attr(cx: &EarlyContext<'_>, item: &rustc_ast::MetaItem) { - if item.has_name(sym::feature) && item.value_str().is_some_and(|v| v.as_str() == "cargo-clippy") { - span_lint_and_sugg( - cx, - DEPRECATED_CLIPPY_CFG_ATTR, - item.span, - "`feature = \"cargo-clippy\"` was replaced by `clippy`", - "replace with", - "clippy".to_string(), - Applicability::MachineApplicable, - ); - } -} - -fn check_deprecated_cfg_recursively(cx: &EarlyContext<'_>, attr: &rustc_ast::MetaItem) { - if let Some(ident) = attr.ident() { - if ["any", "all", "not"].contains(&ident.name.as_str()) { - let Some(list) = attr.meta_item_list() else { return }; - for item in list.iter().filter_map(|item| item.meta_item()) { - check_deprecated_cfg_recursively(cx, item); - } - } else { - check_cargo_clippy_attr(cx, attr); - } - } -} - -fn check_deprecated_cfg(cx: &EarlyContext<'_>, attr: &Attribute) { - if attr.has_name(sym::cfg) - && let Some(list) = attr.meta_item_list() - { - for item in list.iter().filter_map(|item| item.meta_item()) { - check_deprecated_cfg_recursively(cx, item); - } - } -} - -fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute, msrv: &Msrv) { - // check cfg_attr - if attr.has_name(sym::cfg_attr) - && let Some(items) = attr.meta_item_list() - && items.len() == 2 - && let Some(feature_item) = items[0].meta_item() - { - // check for `rustfmt` - if feature_item.has_name(sym::rustfmt) - && msrv.meets(msrvs::TOOL_ATTRIBUTES) - // check for `rustfmt_skip` and `rustfmt::skip` - && let Some(skip_item) = &items[1].meta_item() - && (skip_item.has_name(sym!(rustfmt_skip)) - || skip_item - .path - .segments - .last() - .expect("empty path in attribute") - .ident - .name - == sym::skip) - // Only lint outer attributes, because custom inner attributes are unstable - // Tracking issue: https://github.com/rust-lang/rust/issues/54726 - && attr.style == AttrStyle::Outer - { - span_lint_and_sugg( - cx, - DEPRECATED_CFG_ATTR, - attr.span, - "`cfg_attr` is deprecated for rustfmt and got replaced by tool attributes", - "use", - "#[rustfmt::skip]".to_string(), - Applicability::MachineApplicable, - ); - } else { - check_deprecated_cfg_recursively(cx, feature_item); - if let Some(behind_cfg_attr) = items[1].meta_item() { - check_clippy_cfg_attr(cx, feature_item, behind_cfg_attr, attr); - } - } - } -} - -fn check_clippy_cfg_attr( - cx: &EarlyContext<'_>, - cfg_attr: &rustc_ast::MetaItem, - behind_cfg_attr: &rustc_ast::MetaItem, - attr: &Attribute, -) { - if cfg_attr.has_name(sym::clippy) - && let Some(ident) = behind_cfg_attr.ident() - && Level::from_symbol(ident.name, Some(attr.id)).is_some() - && let Some(items) = behind_cfg_attr.meta_item_list() - { - let nb_items = items.len(); - let mut clippy_lints = Vec::with_capacity(items.len()); - for item in items { - if let Some(meta_item) = item.meta_item() - && let [part1, _] = meta_item.path.segments.as_slice() - && part1.ident.name == sym::clippy - { - clippy_lints.push(item.span()); - } - } - if clippy_lints.is_empty() { - return; - } - if nb_items == clippy_lints.len() { - if let Some(snippet) = snippet_opt(cx, behind_cfg_attr.span) { - span_lint_and_sugg( - cx, - UNNECESSARY_CLIPPY_CFG, - attr.span, - "no need to put clippy lints behind a `clippy` cfg", - "replace with", - format!( - "#{}[{}]", - if attr.style == AttrStyle::Inner { "!" } else { "" }, - snippet - ), - Applicability::MachineApplicable, - ); - } - } else { - let snippet = clippy_lints - .iter() - .filter_map(|sp| snippet_opt(cx, *sp)) - .collect::>() - .join(","); - span_lint_and_note( - cx, - UNNECESSARY_CLIPPY_CFG, - clippy_lints, - "no need to put clippy lints behind a `clippy` cfg", - None, - &format!( - "write instead: `#{}[{}({})]`", - if attr.style == AttrStyle::Inner { "!" } else { "" }, - ident.name, - snippet - ), - ); - } - } -} - -fn check_nested_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) { - for item in items { - if let NestedMetaItem::MetaItem(meta) = item { - if !meta.has_name(sym::any) && !meta.has_name(sym::all) { - continue; - } - if let MetaItemKind::List(list) = &meta.kind { - check_nested_cfg(cx, list); - if list.len() == 1 { - span_lint_and_then( - cx, - NON_MINIMAL_CFG, - meta.span, - "unneeded sub `cfg` when there is only one condition", - |diag| { - if let Some(snippet) = snippet_opt(cx, list[0].span()) { - diag.span_suggestion(meta.span, "try", snippet, Applicability::MaybeIncorrect); - } - }, - ); - } else if list.is_empty() && meta.has_name(sym::all) { - span_lint_and_then( - cx, - NON_MINIMAL_CFG, - meta.span, - "unneeded sub `cfg` when there is no condition", - |_| {}, - ); - } - } - } - } -} - -fn check_nested_misused_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) { - for item in items { - if let NestedMetaItem::MetaItem(meta) = item { - if let Some(ident) = meta.ident() - && ident.name.as_str() == "features" - && let Some(val) = meta.value_str() - { - span_lint_and_sugg( - cx, - MAYBE_MISUSED_CFG, - meta.span, - "'feature' may be misspelled as 'features'", - "did you mean", - format!("feature = \"{val}\""), - Applicability::MaybeIncorrect, - ); - } - if let MetaItemKind::List(list) = &meta.kind { - check_nested_misused_cfg(cx, list); - // If this is not a list, then we check for `cfg(test)`. - } else if let Some(ident) = meta.ident() - && matches!(ident.name.as_str(), "tests" | "Test") - { - span_lint_and_sugg( - cx, - MAYBE_MISUSED_CFG, - meta.span, - &format!("'test' may be misspelled as '{}'", ident.name.as_str()), - "did you mean", - "test".to_string(), - Applicability::MaybeIncorrect, - ); - } - } - } -} - -fn check_minimal_cfg_condition(cx: &EarlyContext<'_>, attr: &Attribute) { - if attr.has_name(sym::cfg) - && let Some(items) = attr.meta_item_list() - { - check_nested_cfg(cx, &items); - } -} - -fn check_misused_cfg(cx: &EarlyContext<'_>, attr: &Attribute) { - if attr.has_name(sym::cfg) - && let Some(items) = attr.meta_item_list() - { - check_nested_misused_cfg(cx, &items); - } -} - -fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) { - fn find_os(name: &str) -> Option<&'static str> { - UNIX_SYSTEMS - .iter() - .chain(NON_UNIX_SYSTEMS.iter()) - .find(|&&os| os == name) - .copied() - } - - fn is_unix(name: &str) -> bool { - UNIX_SYSTEMS.iter().any(|&os| os == name) - } - - fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> { - let mut mismatched = Vec::new(); - - for item in items { - if let NestedMetaItem::MetaItem(meta) = item { - match &meta.kind { - MetaItemKind::List(list) => { - mismatched.extend(find_mismatched_target_os(list)); - }, - MetaItemKind::Word => { - if let Some(ident) = meta.ident() - && let Some(os) = find_os(ident.name.as_str()) - { - mismatched.push((os, ident.span)); - } - }, - MetaItemKind::NameValue(..) => {}, - } - } - } - - mismatched - } - - if attr.has_name(sym::cfg) - && let Some(list) = attr.meta_item_list() - && let mismatched = find_mismatched_target_os(&list) - && !mismatched.is_empty() - { - let mess = "operating system used in target family position"; - - span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, mess, |diag| { - // Avoid showing the unix suggestion multiple times in case - // we have more than one mismatch for unix-like systems - let mut unix_suggested = false; - - for (os, span) in mismatched { - let sugg = format!("target_os = \"{os}\""); - diag.span_suggestion(span, "try", sugg, Applicability::MaybeIncorrect); - - if !unix_suggested && is_unix(os) { - diag.help("did you mean `unix`?"); - unix_suggested = true; - } - } - }); - } -} - -fn is_lint_level(symbol: Symbol, attr_id: AttrId) -> bool { - Level::from_symbol(symbol, Some(attr_id)).is_some() -} diff --git a/clippy_lints/src/attrs/allow_attributes_without_reason.rs b/clippy_lints/src/attrs/allow_attributes_without_reason.rs new file mode 100644 index 0000000000000..df00f23e37e87 --- /dev/null +++ b/clippy_lints/src/attrs/allow_attributes_without_reason.rs @@ -0,0 +1,37 @@ +use super::{Attribute, ALLOW_ATTRIBUTES_WITHOUT_REASON}; +use clippy_utils::diagnostics::span_lint_and_help; +use clippy_utils::is_from_proc_macro; +use rustc_ast::{MetaItemKind, NestedMetaItem}; +use rustc_lint::{LateContext, LintContext}; +use rustc_middle::lint::in_external_macro; +use rustc_span::sym; +use rustc_span::symbol::Symbol; + +pub(super) fn check<'cx>(cx: &LateContext<'cx>, name: Symbol, items: &[NestedMetaItem], attr: &'cx Attribute) { + // Check for the feature + if !cx.tcx.features().lint_reasons { + return; + } + + // Check if the reason is present + if let Some(item) = items.last().and_then(NestedMetaItem::meta_item) + && let MetaItemKind::NameValue(_) = &item.kind + && item.path == sym::reason + { + return; + } + + // Check if the attribute is in an external macro and therefore out of the developer's control + if in_external_macro(cx.sess(), attr.span) || is_from_proc_macro(cx, &attr) { + return; + } + + span_lint_and_help( + cx, + ALLOW_ATTRIBUTES_WITHOUT_REASON, + attr.span, + &format!("`{}` attribute without specifying a reason", name.as_str()), + None, + "try adding a reason at the end with `, reason = \"..\"`", + ); +} diff --git a/clippy_lints/src/attrs/blanket_clippy_restriction_lints.rs b/clippy_lints/src/attrs/blanket_clippy_restriction_lints.rs new file mode 100644 index 0000000000000..9b08fd6d654a5 --- /dev/null +++ b/clippy_lints/src/attrs/blanket_clippy_restriction_lints.rs @@ -0,0 +1,44 @@ +use super::utils::extract_clippy_lint; +use super::BLANKET_CLIPPY_RESTRICTION_LINTS; +use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_then}; +use rustc_ast::NestedMetaItem; +use rustc_lint::{LateContext, Level, LintContext}; +use rustc_span::symbol::Symbol; +use rustc_span::{sym, DUMMY_SP}; + +pub(super) fn check(cx: &LateContext<'_>, name: Symbol, items: &[NestedMetaItem]) { + for lint in items { + if let Some(lint_name) = extract_clippy_lint(lint) { + if lint_name.as_str() == "restriction" && name != sym::allow { + span_lint_and_help( + cx, + BLANKET_CLIPPY_RESTRICTION_LINTS, + lint.span(), + "`clippy::restriction` is not meant to be enabled as a group", + None, + "enable the restriction lints you need individually", + ); + } + } + } +} + +pub(super) fn check_command_line(cx: &LateContext<'_>) { + for (name, level) in &cx.sess().opts.lint_opts { + if name == "clippy::restriction" && *level > Level::Allow { + span_lint_and_then( + cx, + BLANKET_CLIPPY_RESTRICTION_LINTS, + DUMMY_SP, + "`clippy::restriction` is not meant to be enabled as a group", + |diag| { + diag.note(format!( + "because of the command line `--{} clippy::restriction`", + level.as_str() + )); + diag.help("enable the restriction lints you need individually"); + }, + ); + } + } +} diff --git a/clippy_lints/src/attrs/deprecated_cfg_attr.rs b/clippy_lints/src/attrs/deprecated_cfg_attr.rs new file mode 100644 index 0000000000000..e872ab6b4b5f5 --- /dev/null +++ b/clippy_lints/src/attrs/deprecated_cfg_attr.rs @@ -0,0 +1,87 @@ +use super::{unnecessary_clippy_cfg, Attribute, DEPRECATED_CFG_ATTR, DEPRECATED_CLIPPY_CFG_ATTR}; +use clippy_config::msrvs::{self, Msrv}; +use clippy_utils::diagnostics::span_lint_and_sugg; +use rustc_ast::AttrStyle; +use rustc_errors::Applicability; +use rustc_lint::EarlyContext; +use rustc_span::sym; + +pub(super) fn check(cx: &EarlyContext<'_>, attr: &Attribute, msrv: &Msrv) { + // check cfg_attr + if attr.has_name(sym::cfg_attr) + && let Some(items) = attr.meta_item_list() + && items.len() == 2 + && let Some(feature_item) = items[0].meta_item() + { + // check for `rustfmt` + if feature_item.has_name(sym::rustfmt) + && msrv.meets(msrvs::TOOL_ATTRIBUTES) + // check for `rustfmt_skip` and `rustfmt::skip` + && let Some(skip_item) = &items[1].meta_item() + && (skip_item.has_name(sym!(rustfmt_skip)) + || skip_item + .path + .segments + .last() + .expect("empty path in attribute") + .ident + .name + == sym::skip) + // Only lint outer attributes, because custom inner attributes are unstable + // Tracking issue: https://github.com/rust-lang/rust/issues/54726 + && attr.style == AttrStyle::Outer + { + span_lint_and_sugg( + cx, + DEPRECATED_CFG_ATTR, + attr.span, + "`cfg_attr` is deprecated for rustfmt and got replaced by tool attributes", + "use", + "#[rustfmt::skip]".to_string(), + Applicability::MachineApplicable, + ); + } else { + check_deprecated_cfg_recursively(cx, feature_item); + if let Some(behind_cfg_attr) = items[1].meta_item() { + unnecessary_clippy_cfg::check(cx, feature_item, behind_cfg_attr, attr); + } + } + } +} + +pub(super) fn check_clippy(cx: &EarlyContext<'_>, attr: &Attribute) { + if attr.has_name(sym::cfg) + && let Some(list) = attr.meta_item_list() + { + for item in list.iter().filter_map(|item| item.meta_item()) { + check_deprecated_cfg_recursively(cx, item); + } + } +} + +fn check_deprecated_cfg_recursively(cx: &EarlyContext<'_>, attr: &rustc_ast::MetaItem) { + if let Some(ident) = attr.ident() { + if ["any", "all", "not"].contains(&ident.name.as_str()) { + let Some(list) = attr.meta_item_list() else { return }; + for item in list.iter().filter_map(|item| item.meta_item()) { + check_deprecated_cfg_recursively(cx, item); + } + } else { + check_cargo_clippy_attr(cx, attr); + } + } +} + +fn check_cargo_clippy_attr(cx: &EarlyContext<'_>, item: &rustc_ast::MetaItem) { + if item.has_name(sym::feature) && item.value_str().is_some_and(|v| v.as_str() == "cargo-clippy") { + span_lint_and_sugg( + cx, + DEPRECATED_CLIPPY_CFG_ATTR, + item.span, + "`feature = \"cargo-clippy\"` was replaced by `clippy`", + "replace with", + "clippy".to_string(), + Applicability::MachineApplicable, + ); + } +} diff --git a/clippy_lints/src/attrs/deprecated_semver.rs b/clippy_lints/src/attrs/deprecated_semver.rs new file mode 100644 index 0000000000000..1898c145c76a9 --- /dev/null +++ b/clippy_lints/src/attrs/deprecated_semver.rs @@ -0,0 +1,20 @@ +use super::DEPRECATED_SEMVER; +use clippy_utils::diagnostics::span_lint; +use rustc_ast::{LitKind, MetaItemLit}; +use rustc_lint::LateContext; +use rustc_span::Span; +use semver::Version; + +pub(super) fn check(cx: &LateContext<'_>, span: Span, lit: &MetaItemLit) { + if let LitKind::Str(is, _) = lit.kind { + if is.as_str() == "TBD" || Version::parse(is.as_str()).is_ok() { + return; + } + } + span_lint( + cx, + DEPRECATED_SEMVER, + span, + "the since field must contain a semver-compliant version", + ); +} diff --git a/clippy_lints/src/attrs/empty_line_after.rs b/clippy_lints/src/attrs/empty_line_after.rs new file mode 100644 index 0000000000000..ca43e76ac5780 --- /dev/null +++ b/clippy_lints/src/attrs/empty_line_after.rs @@ -0,0 +1,52 @@ +use super::{EMPTY_LINE_AFTER_DOC_COMMENTS, EMPTY_LINE_AFTER_OUTER_ATTR}; +use clippy_utils::diagnostics::span_lint; +use clippy_utils::source::{is_present_in_source, snippet_opt, without_block_comments}; +use rustc_ast::{AttrKind, AttrStyle}; +use rustc_lint::EarlyContext; +use rustc_span::Span; + +/// Check for empty lines after outer attributes. +/// +/// Attributes and documentation comments are both considered outer attributes +/// by the AST. However, the average user likely considers them to be different. +/// Checking for empty lines after each of these attributes is split into two different +/// lints but can share the same logic. +pub(super) fn check(cx: &EarlyContext<'_>, item: &rustc_ast::Item) { + let mut iter = item.attrs.iter().peekable(); + while let Some(attr) = iter.next() { + if (matches!(attr.kind, AttrKind::Normal(..)) || matches!(attr.kind, AttrKind::DocComment(..))) + && attr.style == AttrStyle::Outer + && is_present_in_source(cx, attr.span) + { + let begin_of_attr_to_item = Span::new(attr.span.lo(), item.span.lo(), item.span.ctxt(), item.span.parent()); + let end_of_attr_to_next_attr_or_item = Span::new( + attr.span.hi(), + iter.peek().map_or(item.span.lo(), |next_attr| next_attr.span.lo()), + item.span.ctxt(), + item.span.parent(), + ); + + if let Some(snippet) = snippet_opt(cx, end_of_attr_to_next_attr_or_item) { + let lines = snippet.split('\n').collect::>(); + let lines = without_block_comments(lines); + + if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 { + let (lint_msg, lint_type) = match attr.kind { + AttrKind::DocComment(..) => ( + "found an empty line after a doc comment. \ + Perhaps you need to use `//!` to make a comment on a module, remove the empty line, or make a regular comment with `//`?", + EMPTY_LINE_AFTER_DOC_COMMENTS, + ), + AttrKind::Normal(..) => ( + "found an empty line after an outer attribute. \ + Perhaps you forgot to add a `!` to make it an inner attribute?", + EMPTY_LINE_AFTER_OUTER_ATTR, + ), + }; + + span_lint(cx, lint_type, begin_of_attr_to_item, lint_msg); + } + } + } + } +} diff --git a/clippy_lints/src/attrs/inline_always.rs b/clippy_lints/src/attrs/inline_always.rs new file mode 100644 index 0000000000000..cfcd2cc6a00b7 --- /dev/null +++ b/clippy_lints/src/attrs/inline_always.rs @@ -0,0 +1,29 @@ +use super::utils::is_word; +use super::INLINE_ALWAYS; +use clippy_utils::diagnostics::span_lint; +use rustc_ast::Attribute; +use rustc_lint::LateContext; +use rustc_span::symbol::Symbol; +use rustc_span::{sym, Span}; + +pub(super) fn check(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribute]) { + if span.from_expansion() { + return; + } + + for attr in attrs { + if let Some(values) = attr.meta_item_list() { + if values.len() != 1 || !attr.has_name(sym::inline) { + continue; + } + if is_word(&values[0], sym::always) { + span_lint( + cx, + INLINE_ALWAYS, + attr.span, + &format!("you have declared `#[inline(always)]` on `{name}`. This is usually a bad idea"), + ); + } + } + } +} diff --git a/clippy_lints/src/attrs/maybe_misused_cfg.rs b/clippy_lints/src/attrs/maybe_misused_cfg.rs new file mode 100644 index 0000000000000..5a70866eda587 --- /dev/null +++ b/clippy_lints/src/attrs/maybe_misused_cfg.rs @@ -0,0 +1,51 @@ +use super::{Attribute, MAYBE_MISUSED_CFG}; +use clippy_utils::diagnostics::span_lint_and_sugg; +use rustc_ast::{MetaItemKind, NestedMetaItem}; +use rustc_errors::Applicability; +use rustc_lint::EarlyContext; +use rustc_span::sym; + +pub(super) fn check(cx: &EarlyContext<'_>, attr: &Attribute) { + if attr.has_name(sym::cfg) + && let Some(items) = attr.meta_item_list() + { + check_nested_misused_cfg(cx, &items); + } +} + +fn check_nested_misused_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) { + for item in items { + if let NestedMetaItem::MetaItem(meta) = item { + if let Some(ident) = meta.ident() + && ident.name.as_str() == "features" + && let Some(val) = meta.value_str() + { + span_lint_and_sugg( + cx, + MAYBE_MISUSED_CFG, + meta.span, + "'feature' may be misspelled as 'features'", + "did you mean", + format!("feature = \"{val}\""), + Applicability::MaybeIncorrect, + ); + } + if let MetaItemKind::List(list) = &meta.kind { + check_nested_misused_cfg(cx, list); + // If this is not a list, then we check for `cfg(test)`. + } else if let Some(ident) = meta.ident() + && matches!(ident.name.as_str(), "tests" | "Test") + { + span_lint_and_sugg( + cx, + MAYBE_MISUSED_CFG, + meta.span, + &format!("'test' may be misspelled as '{}'", ident.name.as_str()), + "did you mean", + "test".to_string(), + Applicability::MaybeIncorrect, + ); + } + } + } +} diff --git a/clippy_lints/src/attrs/mismatched_target_os.rs b/clippy_lints/src/attrs/mismatched_target_os.rs new file mode 100644 index 0000000000000..b1cc0a763c5e9 --- /dev/null +++ b/clippy_lints/src/attrs/mismatched_target_os.rs @@ -0,0 +1,90 @@ +use super::{Attribute, MISMATCHED_TARGET_OS}; +use clippy_utils::diagnostics::span_lint_and_then; +use rustc_ast::{MetaItemKind, NestedMetaItem}; +use rustc_errors::Applicability; +use rustc_lint::EarlyContext; +use rustc_span::{sym, Span}; + +static UNIX_SYSTEMS: &[&str] = &[ + "android", + "dragonfly", + "emscripten", + "freebsd", + "fuchsia", + "haiku", + "illumos", + "ios", + "l4re", + "linux", + "macos", + "netbsd", + "openbsd", + "redox", + "solaris", + "vxworks", +]; + +// NOTE: windows is excluded from the list because it's also a valid target family. +static NON_UNIX_SYSTEMS: &[&str] = &["hermit", "none", "wasi"]; + +pub(super) fn check(cx: &EarlyContext<'_>, attr: &Attribute) { + fn find_os(name: &str) -> Option<&'static str> { + UNIX_SYSTEMS + .iter() + .chain(NON_UNIX_SYSTEMS.iter()) + .find(|&&os| os == name) + .copied() + } + + fn is_unix(name: &str) -> bool { + UNIX_SYSTEMS.iter().any(|&os| os == name) + } + + fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> { + let mut mismatched = Vec::new(); + + for item in items { + if let NestedMetaItem::MetaItem(meta) = item { + match &meta.kind { + MetaItemKind::List(list) => { + mismatched.extend(find_mismatched_target_os(list)); + }, + MetaItemKind::Word => { + if let Some(ident) = meta.ident() + && let Some(os) = find_os(ident.name.as_str()) + { + mismatched.push((os, ident.span)); + } + }, + MetaItemKind::NameValue(..) => {}, + } + } + } + + mismatched + } + + if attr.has_name(sym::cfg) + && let Some(list) = attr.meta_item_list() + && let mismatched = find_mismatched_target_os(&list) + && !mismatched.is_empty() + { + let mess = "operating system used in target family position"; + + span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, mess, |diag| { + // Avoid showing the unix suggestion multiple times in case + // we have more than one mismatch for unix-like systems + let mut unix_suggested = false; + + for (os, span) in mismatched { + let sugg = format!("target_os = \"{os}\""); + diag.span_suggestion(span, "try", sugg, Applicability::MaybeIncorrect); + + if !unix_suggested && is_unix(os) { + diag.help("did you mean `unix`?"); + unix_suggested = true; + } + } + }); + } +} diff --git a/clippy_lints/src/attrs/mixed_attributes_style.rs b/clippy_lints/src/attrs/mixed_attributes_style.rs new file mode 100644 index 0000000000000..c2e21cfd33006 --- /dev/null +++ b/clippy_lints/src/attrs/mixed_attributes_style.rs @@ -0,0 +1,30 @@ +use super::MIXED_ATTRIBUTES_STYLE; +use clippy_utils::diagnostics::span_lint; +use rustc_ast::AttrStyle; +use rustc_lint::EarlyContext; + +pub(super) fn check(cx: &EarlyContext<'_>, item: &rustc_ast::Item) { + let mut has_outer = false; + let mut has_inner = false; + + for attr in &item.attrs { + if attr.span.from_expansion() { + continue; + } + match attr.style { + AttrStyle::Inner => has_inner = true, + AttrStyle::Outer => has_outer = true, + } + } + if !has_outer || !has_inner { + return; + } + let mut attrs_iter = item.attrs.iter().filter(|attr| !attr.span.from_expansion()); + let span = attrs_iter.next().unwrap().span; + span_lint( + cx, + MIXED_ATTRIBUTES_STYLE, + span.with_hi(attrs_iter.last().unwrap().span.hi()), + "item has both inner and outer attributes", + ); +} diff --git a/clippy_lints/src/attrs/mod.rs b/clippy_lints/src/attrs/mod.rs new file mode 100644 index 0000000000000..c4c65d3248a7d --- /dev/null +++ b/clippy_lints/src/attrs/mod.rs @@ -0,0 +1,588 @@ +//! checks for attributes + +mod allow_attributes_without_reason; +mod blanket_clippy_restriction_lints; +mod deprecated_cfg_attr; +mod deprecated_semver; +mod empty_line_after; +mod inline_always; +mod maybe_misused_cfg; +mod mismatched_target_os; +mod mixed_attributes_style; +mod non_minimal_cfg; +mod should_panic_without_expect; +mod unnecessary_clippy_cfg; +mod useless_attribute; +mod utils; + +use clippy_config::msrvs::Msrv; +use rustc_ast::{Attribute, MetaItemKind, NestedMetaItem}; +use rustc_hir::{ImplItem, Item, ItemKind, TraitItem}; +use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, impl_lint_pass}; +use rustc_span::sym; +use utils::{is_lint_level, is_relevant_impl, is_relevant_item, is_relevant_trait}; + +declare_clippy_lint! { + /// ### What it does + /// Checks for items annotated with `#[inline(always)]`, + /// unless the annotated function is empty or simply panics. + /// + /// ### Why is this bad? + /// While there are valid uses of this annotation (and once + /// you know when to use it, by all means `allow` this lint), it's a common + /// newbie-mistake to pepper one's code with it. + /// + /// As a rule of thumb, before slapping `#[inline(always)]` on a function, + /// measure if that additional function call really affects your runtime profile + /// sufficiently to make up for the increase in compile time. + /// + /// ### Known problems + /// False positives, big time. This lint is meant to be + /// deactivated by everyone doing serious performance work. This means having + /// done the measurement. + /// + /// ### Example + /// ```ignore + /// #[inline(always)] + /// fn not_quite_hot_code(..) { ... } + /// ``` + #[clippy::version = "pre 1.29.0"] + pub INLINE_ALWAYS, + pedantic, + "use of `#[inline(always)]`" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `extern crate` and `use` items annotated with + /// lint attributes. + /// + /// This lint permits lint attributes for lints emitted on the items themself. + /// For `use` items these lints are: + /// * deprecated + /// * unreachable_pub + /// * unused_imports + /// * clippy::enum_glob_use + /// * clippy::macro_use_imports + /// * clippy::wildcard_imports + /// + /// For `extern crate` items these lints are: + /// * `unused_imports` on items with `#[macro_use]` + /// + /// ### Why is this bad? + /// Lint attributes have no effect on crate imports. Most + /// likely a `!` was forgotten. + /// + /// ### Example + /// ```ignore + /// #[deny(dead_code)] + /// extern crate foo; + /// #[forbid(dead_code)] + /// use foo::bar; + /// ``` + /// + /// Use instead: + /// ```rust,ignore + /// #[allow(unused_imports)] + /// use foo::baz; + /// #[allow(unused_imports)] + /// #[macro_use] + /// extern crate baz; + /// ``` + #[clippy::version = "pre 1.29.0"] + pub USELESS_ATTRIBUTE, + correctness, + "use of lint attributes on `extern crate` items" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `#[deprecated]` annotations with a `since` + /// field that is not a valid semantic version. Also allows "TBD" to signal + /// future deprecation. + /// + /// ### Why is this bad? + /// For checking the version of the deprecation, it must be + /// a valid semver. Failing that, the contained information is useless. + /// + /// ### Example + /// ```no_run + /// #[deprecated(since = "forever")] + /// fn something_else() { /* ... */ } + /// ``` + #[clippy::version = "pre 1.29.0"] + pub DEPRECATED_SEMVER, + correctness, + "use of `#[deprecated(since = \"x\")]` where x is not semver" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for empty lines after outer attributes + /// + /// ### Why is this bad? + /// Most likely the attribute was meant to be an inner attribute using a '!'. + /// If it was meant to be an outer attribute, then the following item + /// should not be separated by empty lines. + /// + /// ### Known problems + /// Can cause false positives. + /// + /// From the clippy side it's difficult to detect empty lines between an attributes and the + /// following item because empty lines and comments are not part of the AST. The parsing + /// currently works for basic cases but is not perfect. + /// + /// ### Example + /// ```no_run + /// #[allow(dead_code)] + /// + /// fn not_quite_good_code() { } + /// ``` + /// + /// Use instead: + /// ```no_run + /// // Good (as inner attribute) + /// #![allow(dead_code)] + /// + /// fn this_is_fine() { } + /// + /// // or + /// + /// // Good (as outer attribute) + /// #[allow(dead_code)] + /// fn this_is_fine_too() { } + /// ``` + #[clippy::version = "pre 1.29.0"] + pub EMPTY_LINE_AFTER_OUTER_ATTR, + nursery, + "empty line after outer attribute" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for empty lines after documentation comments. + /// + /// ### Why is this bad? + /// The documentation comment was most likely meant to be an inner attribute or regular comment. + /// If it was intended to be a documentation comment, then the empty line should be removed to + /// be more idiomatic. + /// + /// ### Known problems + /// Only detects empty lines immediately following the documentation. If the doc comment is followed + /// by an attribute and then an empty line, this lint will not trigger. Use `empty_line_after_outer_attr` + /// in combination with this lint to detect both cases. + /// + /// Does not detect empty lines after doc attributes (e.g. `#[doc = ""]`). + /// + /// ### Example + /// ```no_run + /// /// Some doc comment with a blank line after it. + /// + /// fn not_quite_good_code() { } + /// ``` + /// + /// Use instead: + /// ```no_run + /// /// Good (no blank line) + /// fn this_is_fine() { } + /// ``` + /// + /// ```no_run + /// // Good (convert to a regular comment) + /// + /// fn this_is_fine_too() { } + /// ``` + /// + /// ```no_run + /// //! Good (convert to a comment on an inner attribute) + /// + /// fn this_is_fine_as_well() { } + /// ``` + #[clippy::version = "1.70.0"] + pub EMPTY_LINE_AFTER_DOC_COMMENTS, + nursery, + "empty line after documentation comments" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category. + /// + /// ### Why is this bad? + /// Restriction lints sometimes are in contrast with other lints or even go against idiomatic rust. + /// These lints should only be enabled on a lint-by-lint basis and with careful consideration. + /// + /// ### Example + /// ```no_run + /// #![deny(clippy::restriction)] + /// ``` + /// + /// Use instead: + /// ```no_run + /// #![deny(clippy::as_conversions)] + /// ``` + #[clippy::version = "1.47.0"] + pub BLANKET_CLIPPY_RESTRICTION_LINTS, + suspicious, + "enabling the complete restriction group" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it + /// with `#[rustfmt::skip]`. + /// + /// ### Why is this bad? + /// Since tool_attributes ([rust-lang/rust#44690](https://github.com/rust-lang/rust/issues/44690)) + /// are stable now, they should be used instead of the old `cfg_attr(rustfmt)` attributes. + /// + /// ### Known problems + /// This lint doesn't detect crate level inner attributes, because they get + /// processed before the PreExpansionPass lints get executed. See + /// [#3123](https://github.com/rust-lang/rust-clippy/pull/3123#issuecomment-422321765) + /// + /// ### Example + /// ```no_run + /// #[cfg_attr(rustfmt, rustfmt_skip)] + /// fn main() { } + /// ``` + /// + /// Use instead: + /// ```no_run + /// #[rustfmt::skip] + /// fn main() { } + /// ``` + #[clippy::version = "1.32.0"] + pub DEPRECATED_CFG_ATTR, + complexity, + "usage of `cfg_attr(rustfmt)` instead of tool attributes" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for cfg attributes having operating systems used in target family position. + /// + /// ### Why is this bad? + /// The configuration option will not be recognised and the related item will not be included + /// by the conditional compilation engine. + /// + /// ### Example + /// ```no_run + /// #[cfg(linux)] + /// fn conditional() { } + /// ``` + /// + /// Use instead: + /// ```no_run + /// # mod hidden { + /// #[cfg(target_os = "linux")] + /// fn conditional() { } + /// # } + /// + /// // or + /// + /// #[cfg(unix)] + /// fn conditional() { } + /// ``` + /// Check the [Rust Reference](https://doc.rust-lang.org/reference/conditional-compilation.html#target_os) for more details. + #[clippy::version = "1.45.0"] + pub MISMATCHED_TARGET_OS, + correctness, + "usage of `cfg(operating_system)` instead of `cfg(target_os = \"operating_system\")`" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for attributes that allow lints without a reason. + /// + /// (This requires the `lint_reasons` feature) + /// + /// ### Why is this bad? + /// Allowing a lint should always have a reason. This reason should be documented to + /// ensure that others understand the reasoning + /// + /// ### Example + /// ```no_run + /// #![feature(lint_reasons)] + /// + /// #![allow(clippy::some_lint)] + /// ``` + /// + /// Use instead: + /// ```no_run + /// #![feature(lint_reasons)] + /// + /// #![allow(clippy::some_lint, reason = "False positive rust-lang/rust-clippy#1002020")] + /// ``` + #[clippy::version = "1.61.0"] + pub ALLOW_ATTRIBUTES_WITHOUT_REASON, + restriction, + "ensures that all `allow` and `expect` attributes have a reason" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `#[should_panic]` attributes without specifying the expected panic message. + /// + /// ### Why is this bad? + /// The expected panic message should be specified to ensure that the test is actually + /// panicking with the expected message, and not another unrelated panic. + /// + /// ### Example + /// ```no_run + /// fn random() -> i32 { 0 } + /// + /// #[should_panic] + /// #[test] + /// fn my_test() { + /// let _ = 1 / random(); + /// } + /// ``` + /// + /// Use instead: + /// ```no_run + /// fn random() -> i32 { 0 } + /// + /// #[should_panic = "attempt to divide by zero"] + /// #[test] + /// fn my_test() { + /// let _ = 1 / random(); + /// } + /// ``` + #[clippy::version = "1.74.0"] + pub SHOULD_PANIC_WITHOUT_EXPECT, + pedantic, + "ensures that all `should_panic` attributes specify its expected panic message" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `any` and `all` combinators in `cfg` with only one condition. + /// + /// ### Why is this bad? + /// If there is only one condition, no need to wrap it into `any` or `all` combinators. + /// + /// ### Example + /// ```no_run + /// #[cfg(any(unix))] + /// pub struct Bar; + /// ``` + /// + /// Use instead: + /// ```no_run + /// #[cfg(unix)] + /// pub struct Bar; + /// ``` + #[clippy::version = "1.71.0"] + pub NON_MINIMAL_CFG, + style, + "ensure that all `cfg(any())` and `cfg(all())` have more than one condition" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `#[cfg(features = "...")]` and suggests to replace it with + /// `#[cfg(feature = "...")]`. + /// + /// It also checks if `cfg(test)` was misspelled. + /// + /// ### Why is this bad? + /// Misspelling `feature` as `features` or `test` as `tests` can be sometimes hard to spot. It + /// may cause conditional compilation not work quietly. + /// + /// ### Example + /// ```no_run + /// #[cfg(features = "some-feature")] + /// fn conditional() { } + /// #[cfg(tests)] + /// mod tests { } + /// ``` + /// + /// Use instead: + /// ```no_run + /// #[cfg(feature = "some-feature")] + /// fn conditional() { } + /// #[cfg(test)] + /// mod tests { } + /// ``` + #[clippy::version = "1.69.0"] + pub MAYBE_MISUSED_CFG, + suspicious, + "prevent from misusing the wrong attr name" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `#[cfg_attr(feature = "cargo-clippy", ...)]` and for + /// `#[cfg(feature = "cargo-clippy")]` and suggests to replace it with + /// `#[cfg_attr(clippy, ...)]` or `#[cfg(clippy)]`. + /// + /// ### Why is this bad? + /// This feature has been deprecated for years and shouldn't be used anymore. + /// + /// ### Example + /// ```no_run + /// #[cfg(feature = "cargo-clippy")] + /// struct Bar; + /// ``` + /// + /// Use instead: + /// ```no_run + /// #[cfg(clippy)] + /// struct Bar; + /// ``` + #[clippy::version = "1.78.0"] + pub DEPRECATED_CLIPPY_CFG_ATTR, + suspicious, + "usage of `cfg(feature = \"cargo-clippy\")` instead of `cfg(clippy)`" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for `#[cfg_attr(clippy, allow(clippy::lint))]` + /// and suggests to replace it with `#[allow(clippy::lint)]`. + /// + /// ### Why is this bad? + /// There is no reason to put clippy attributes behind a clippy `cfg` as they are not + /// run by anything else than clippy. + /// + /// ### Example + /// ```no_run + /// #![cfg_attr(clippy, allow(clippy::deprecated_cfg_attr))] + /// ``` + /// + /// Use instead: + /// ```no_run + /// #![allow(clippy::deprecated_cfg_attr)] + /// ``` + #[clippy::version = "1.78.0"] + pub UNNECESSARY_CLIPPY_CFG, + suspicious, + "usage of `cfg_attr(clippy, allow(clippy::lint))` instead of `allow(clippy::lint)`" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks that an item has only one kind of attributes. + /// + /// ### Why is this bad? + /// Having both kinds of attributes makes it more complicated to read code. + /// + /// ### Example + /// ```no_run + /// #[cfg(linux)] + /// pub fn foo() { + /// #![cfg(windows)] + /// } + /// ``` + /// Use instead: + /// ```no_run + /// #[cfg(linux)] + /// #[cfg(windows)] + /// pub fn foo() { + /// } + /// ``` + #[clippy::version = "1.78.0"] + pub MIXED_ATTRIBUTES_STYLE, + suspicious, + "item has both inner and outer attributes" +} + +declare_lint_pass!(Attributes => [ + ALLOW_ATTRIBUTES_WITHOUT_REASON, + INLINE_ALWAYS, + DEPRECATED_SEMVER, + USELESS_ATTRIBUTE, + BLANKET_CLIPPY_RESTRICTION_LINTS, + SHOULD_PANIC_WITHOUT_EXPECT, +]); + +impl<'tcx> LateLintPass<'tcx> for Attributes { + fn check_crate(&mut self, cx: &LateContext<'tcx>) { + blanket_clippy_restriction_lints::check_command_line(cx); + } + + fn check_attribute(&mut self, cx: &LateContext<'tcx>, attr: &'tcx Attribute) { + if let Some(items) = &attr.meta_item_list() { + if let Some(ident) = attr.ident() { + if is_lint_level(ident.name, attr.id) { + blanket_clippy_restriction_lints::check(cx, ident.name, items); + } + if matches!(ident.name, sym::allow | sym::expect) { + allow_attributes_without_reason::check(cx, ident.name, items, attr); + } + if items.is_empty() || !attr.has_name(sym::deprecated) { + return; + } + for item in items { + if let NestedMetaItem::MetaItem(mi) = &item + && let MetaItemKind::NameValue(lit) = &mi.kind + && mi.has_name(sym::since) + { + deprecated_semver::check(cx, item.span(), lit); + } + } + } + } + if attr.has_name(sym::should_panic) { + should_panic_without_expect::check(cx, attr); + } + } + + fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) { + let attrs = cx.tcx.hir().attrs(item.hir_id()); + if is_relevant_item(cx, item) { + inline_always::check(cx, item.span, item.ident.name, attrs); + } + match item.kind { + ItemKind::ExternCrate(..) | ItemKind::Use(..) => useless_attribute::check(cx, item, attrs), + _ => {}, + } + } + + fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) { + if is_relevant_impl(cx, item) { + inline_always::check(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id())); + } + } + + fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) { + if is_relevant_trait(cx, item) { + inline_always::check(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id())); + } + } +} + +pub struct EarlyAttributes { + pub msrv: Msrv, +} + +impl_lint_pass!(EarlyAttributes => [ + DEPRECATED_CFG_ATTR, + MISMATCHED_TARGET_OS, + EMPTY_LINE_AFTER_OUTER_ATTR, + EMPTY_LINE_AFTER_DOC_COMMENTS, + NON_MINIMAL_CFG, + MAYBE_MISUSED_CFG, + DEPRECATED_CLIPPY_CFG_ATTR, + UNNECESSARY_CLIPPY_CFG, + MIXED_ATTRIBUTES_STYLE, +]); + +impl EarlyLintPass for EarlyAttributes { + fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) { + empty_line_after::check(cx, item); + mixed_attributes_style::check(cx, item); + } + + fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) { + deprecated_cfg_attr::check(cx, attr, &self.msrv); + deprecated_cfg_attr::check_clippy(cx, attr); + mismatched_target_os::check(cx, attr); + non_minimal_cfg::check(cx, attr); + maybe_misused_cfg::check(cx, attr); + } + + extract_msrv_attr!(EarlyContext); +} diff --git a/clippy_lints/src/attrs/non_minimal_cfg.rs b/clippy_lints/src/attrs/non_minimal_cfg.rs new file mode 100644 index 0000000000000..3fde70615853d --- /dev/null +++ b/clippy_lints/src/attrs/non_minimal_cfg.rs @@ -0,0 +1,49 @@ +use super::{Attribute, NON_MINIMAL_CFG}; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::source::snippet_opt; +use rustc_ast::{MetaItemKind, NestedMetaItem}; +use rustc_errors::Applicability; +use rustc_lint::EarlyContext; +use rustc_span::sym; + +pub(super) fn check(cx: &EarlyContext<'_>, attr: &Attribute) { + if attr.has_name(sym::cfg) + && let Some(items) = attr.meta_item_list() + { + check_nested_cfg(cx, &items); + } +} + +fn check_nested_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) { + for item in items { + if let NestedMetaItem::MetaItem(meta) = item { + if !meta.has_name(sym::any) && !meta.has_name(sym::all) { + continue; + } + if let MetaItemKind::List(list) = &meta.kind { + check_nested_cfg(cx, list); + if list.len() == 1 { + span_lint_and_then( + cx, + NON_MINIMAL_CFG, + meta.span, + "unneeded sub `cfg` when there is only one condition", + |diag| { + if let Some(snippet) = snippet_opt(cx, list[0].span()) { + diag.span_suggestion(meta.span, "try", snippet, Applicability::MaybeIncorrect); + } + }, + ); + } else if list.is_empty() && meta.has_name(sym::all) { + span_lint_and_then( + cx, + NON_MINIMAL_CFG, + meta.span, + "unneeded sub `cfg` when there is no condition", + |_| {}, + ); + } + } + } + } +} diff --git a/clippy_lints/src/attrs/should_panic_without_expect.rs b/clippy_lints/src/attrs/should_panic_without_expect.rs new file mode 100644 index 0000000000000..2d45cbbf621f4 --- /dev/null +++ b/clippy_lints/src/attrs/should_panic_without_expect.rs @@ -0,0 +1,54 @@ +use super::{Attribute, SHOULD_PANIC_WITHOUT_EXPECT}; +use clippy_utils::diagnostics::span_lint_and_sugg; +use rustc_ast::token::{Token, TokenKind}; +use rustc_ast::tokenstream::TokenTree; +use rustc_ast::{AttrArgs, AttrArgsEq, AttrKind}; +use rustc_errors::Applicability; +use rustc_lint::LateContext; +use rustc_span::sym; + +pub(super) fn check(cx: &LateContext<'_>, attr: &Attribute) { + if let AttrKind::Normal(normal_attr) = &attr.kind { + if let AttrArgs::Eq(_, AttrArgsEq::Hir(_)) = &normal_attr.item.args { + // `#[should_panic = ".."]` found, good + return; + } + + if let AttrArgs::Delimited(args) = &normal_attr.item.args + && let mut tt_iter = args.tokens.trees() + && let Some(TokenTree::Token( + Token { + kind: TokenKind::Ident(sym::expected, _), + .. + }, + _, + )) = tt_iter.next() + && let Some(TokenTree::Token( + Token { + kind: TokenKind::Eq, .. + }, + _, + )) = tt_iter.next() + && let Some(TokenTree::Token( + Token { + kind: TokenKind::Literal(_), + .. + }, + _, + )) = tt_iter.next() + { + // `#[should_panic(expected = "..")]` found, good + return; + } + + span_lint_and_sugg( + cx, + SHOULD_PANIC_WITHOUT_EXPECT, + attr.span, + "#[should_panic] attribute without a reason", + "consider specifying the expected panic", + "#[should_panic(expected = /* panic message */)]".into(), + Applicability::HasPlaceholders, + ); + } +} diff --git a/clippy_lints/src/attrs/unnecessary_clippy_cfg.rs b/clippy_lints/src/attrs/unnecessary_clippy_cfg.rs new file mode 100644 index 0000000000000..05da69636c62f --- /dev/null +++ b/clippy_lints/src/attrs/unnecessary_clippy_cfg.rs @@ -0,0 +1,70 @@ +use super::{Attribute, UNNECESSARY_CLIPPY_CFG}; +use clippy_utils::diagnostics::{span_lint_and_note, span_lint_and_sugg}; +use clippy_utils::source::snippet_opt; +use rustc_ast::AttrStyle; +use rustc_errors::Applicability; +use rustc_lint::{EarlyContext, Level}; +use rustc_span::sym; + +pub(super) fn check( + cx: &EarlyContext<'_>, + cfg_attr: &rustc_ast::MetaItem, + behind_cfg_attr: &rustc_ast::MetaItem, + attr: &Attribute, +) { + if cfg_attr.has_name(sym::clippy) + && let Some(ident) = behind_cfg_attr.ident() + && Level::from_symbol(ident.name, Some(attr.id)).is_some() + && let Some(items) = behind_cfg_attr.meta_item_list() + { + let nb_items = items.len(); + let mut clippy_lints = Vec::with_capacity(items.len()); + for item in items { + if let Some(meta_item) = item.meta_item() + && let [part1, _] = meta_item.path.segments.as_slice() + && part1.ident.name == sym::clippy + { + clippy_lints.push(item.span()); + } + } + if clippy_lints.is_empty() { + return; + } + if nb_items == clippy_lints.len() { + if let Some(snippet) = snippet_opt(cx, behind_cfg_attr.span) { + span_lint_and_sugg( + cx, + UNNECESSARY_CLIPPY_CFG, + attr.span, + "no need to put clippy lints behind a `clippy` cfg", + "replace with", + format!( + "#{}[{}]", + if attr.style == AttrStyle::Inner { "!" } else { "" }, + snippet + ), + Applicability::MachineApplicable, + ); + } + } else { + let snippet = clippy_lints + .iter() + .filter_map(|sp| snippet_opt(cx, *sp)) + .collect::>() + .join(","); + span_lint_and_note( + cx, + UNNECESSARY_CLIPPY_CFG, + clippy_lints, + "no need to put clippy lints behind a `clippy` cfg", + None, + &format!( + "write instead: `#{}[{}({})]`", + if attr.style == AttrStyle::Inner { "!" } else { "" }, + ident.name, + snippet + ), + ); + } + } +} diff --git a/clippy_lints/src/attrs/useless_attribute.rs b/clippy_lints/src/attrs/useless_attribute.rs new file mode 100644 index 0000000000000..7575f502a7c29 --- /dev/null +++ b/clippy_lints/src/attrs/useless_attribute.rs @@ -0,0 +1,73 @@ +use super::utils::{extract_clippy_lint, is_lint_level, is_word}; +use super::{Attribute, USELESS_ATTRIBUTE}; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::source::{first_line_of_span, snippet_opt}; +use rustc_errors::Applicability; +use rustc_hir::{Item, ItemKind}; +use rustc_lint::{LateContext, LintContext}; +use rustc_middle::lint::in_external_macro; +use rustc_span::sym; + +pub(super) fn check(cx: &LateContext<'_>, 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().map_or(false, |ident| is_lint_level(ident.name, attr.id)) { + for lint in lint_list { + match item.kind { + ItemKind::Use(..) => { + if is_word(lint, sym::unused_imports) + || is_word(lint, sym::deprecated) + || is_word(lint, sym!(unreachable_pub)) + || is_word(lint, sym!(unused)) + || is_word(lint, sym!(unused_import_braces)) + || extract_clippy_lint(lint).map_or(false, |s| { + matches!( + s.as_str(), + "wildcard_imports" + | "enum_glob_use" + | "redundant_pub_crate" + | "macro_use_imports" + | "unsafe_removed_from_name" + | "module_name_repetitions" + | "single_component_path_imports" + ) + }) + { + 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(mut sugg) = snippet_opt(cx, line_span) { + if sugg.contains("#[") { + span_lint_and_then(cx, USELESS_ATTRIBUTE, line_span, "useless lint attribute", |diag| { + sugg = sugg.replacen("#[", "#![", 1); + diag.span_suggestion( + line_span, + "if you just forgot a `!`, use", + sugg, + Applicability::MaybeIncorrect, + ); + }); + } + } + } + } + } +} diff --git a/clippy_lints/src/attrs/utils.rs b/clippy_lints/src/attrs/utils.rs new file mode 100644 index 0000000000000..9b36cc00444f3 --- /dev/null +++ b/clippy_lints/src/attrs/utils.rs @@ -0,0 +1,87 @@ +use clippy_utils::macros::{is_panic, macro_backtrace}; +use rustc_ast::{AttrId, NestedMetaItem}; +use rustc_hir::{ + Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind, +}; +use rustc_lint::{LateContext, Level}; +use rustc_middle::ty; +use rustc_span::sym; +use rustc_span::symbol::Symbol; + +pub(super) fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool { + if let NestedMetaItem::MetaItem(mi) = &nmi { + mi.is_word() && mi.has_name(expected) + } else { + false + } +} + +pub(super) fn is_lint_level(symbol: Symbol, attr_id: AttrId) -> bool { + Level::from_symbol(symbol, Some(attr_id)).is_some() +} + +pub(super) fn is_relevant_item(cx: &LateContext<'_>, item: &Item<'_>) -> bool { + if let ItemKind::Fn(_, _, eid) = item.kind { + is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value) + } else { + true + } +} + +pub(super) fn is_relevant_impl(cx: &LateContext<'_>, item: &ImplItem<'_>) -> bool { + match item.kind { + ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value), + _ => false, + } +} + +pub(super) fn is_relevant_trait(cx: &LateContext<'_>, item: &TraitItem<'_>) -> bool { + match item.kind { + TraitItemKind::Fn(_, TraitFn::Required(_)) => true, + TraitItemKind::Fn(_, TraitFn::Provided(eid)) => { + is_relevant_expr(cx, cx.tcx.typeck_body(eid), cx.tcx.hir().body(eid).value) + }, + _ => false, + } +} + +fn is_relevant_block(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, block: &Block<'_>) -> bool { + block.stmts.first().map_or( + block + .expr + .as_ref() + .map_or(false, |e| is_relevant_expr(cx, typeck_results, e)), + |stmt| match &stmt.kind { + StmtKind::Local(_) => true, + StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, typeck_results, expr), + StmtKind::Item(_) => false, + }, + ) +} + +fn is_relevant_expr(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, expr: &Expr<'_>) -> bool { + if macro_backtrace(expr.span).last().map_or(false, |macro_call| { + is_panic(cx, macro_call.def_id) || cx.tcx.item_name(macro_call.def_id) == sym::unreachable + }) { + return false; + } + match &expr.kind { + ExprKind::Block(block, _) => is_relevant_block(cx, typeck_results, block), + ExprKind::Ret(Some(e)) => is_relevant_expr(cx, typeck_results, e), + ExprKind::Ret(None) | ExprKind::Break(_, None) => false, + _ => true, + } +} + +/// Returns the lint name if it is clippy lint. +pub(super) fn extract_clippy_lint(lint: &NestedMetaItem) -> Option { + if let Some(meta_item) = lint.meta_item() + && meta_item.path.segments.len() > 1 + && let tool_name = meta_item.path.segments[0].ident + && tool_name.name == sym::clippy + { + let lint_name = meta_item.path.segments.last().unwrap().ident.name; + return Some(lint_name); + } + None +}