diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/attrs.rs')
| -rw-r--r-- | src/tools/clippy/clippy_lints/src/attrs.rs | 144 |
1 files changed, 136 insertions, 8 deletions
diff --git a/src/tools/clippy/clippy_lints/src/attrs.rs b/src/tools/clippy/clippy_lints/src/attrs.rs index 751c26267..897495ba1 100644 --- a/src/tools/clippy/clippy_lints/src/attrs.rs +++ b/src/tools/clippy/clippy_lints/src/attrs.rs @@ -178,6 +178,52 @@ declare_clippy_lint! { declare_clippy_lint! { /// ### What it does + /// Checks for empty lines after documenation 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 + /// ```rust + /// /// Some doc comment with a blank line after it. + /// + /// fn not_quite_good_code() { } + /// ``` + /// + /// Use instead: + /// ```rust + /// /// Good (no blank line) + /// fn this_is_fine() { } + /// ``` + /// + /// ```rust + /// // Good (convert to a regular comment) + /// + /// fn this_is_fine_too() { } + /// ``` + /// + /// ```rust + /// //! 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? @@ -292,6 +338,30 @@ declare_clippy_lint! { "ensures that all `allow` and `expect` attributes have a reason" } +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 + /// ```rust + /// #[cfg(any(unix))] + /// pub struct Bar; + /// ``` + /// + /// Use instead: + /// ```rust + /// #[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_lint_pass!(Attributes => [ ALLOW_ATTRIBUTES_WITHOUT_REASON, INLINE_ALWAYS, @@ -604,6 +674,8 @@ impl_lint_pass!(EarlyAttributes => [ DEPRECATED_CFG_ATTR, MISMATCHED_TARGET_OS, EMPTY_LINE_AFTER_OUTER_ATTR, + EMPTY_LINE_AFTER_DOC_COMMENTS, + NON_MINIMAL_CFG, ]); impl EarlyLintPass for EarlyAttributes { @@ -614,15 +686,22 @@ impl EarlyLintPass for EarlyAttributes { fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) { check_deprecated_cfg_attr(cx, attr, &self.msrv); check_mismatched_target_os(cx, attr); + check_minimal_cfg_condition(cx, attr); } extract_msrv_attr!(EarlyContext); } +/// Check for empty lines after outer attributes. +/// +/// Attributes and documenation 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(..)) + if (matches!(attr.kind, AttrKind::Normal(..)) || matches!(attr.kind, AttrKind::DocComment(..))) && attr.style == AttrStyle::Outer && is_present_in_source(cx, attr.span) { @@ -639,13 +718,20 @@ fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::It let lines = without_block_comments(lines); if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 { - span_lint( - cx, - EMPTY_LINE_AFTER_OUTER_ATTR, - begin_of_attr_to_item, - "found an empty line after an outer attribute. \ - Perhaps you forgot to add a `!` to make it an inner attribute?", - ); + 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); } } } @@ -690,6 +776,48 @@ fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute, msrv: &Msr } } +fn check_nested_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) { + for item in items.iter() { + 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_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_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) { fn find_os(name: &str) -> Option<&'static str> { UNIX_SYSTEMS |