//! checks for attributes
-use crate::reexport::Name;
use crate::utils::{
- first_line_of_span, is_present_in_source, match_def_path, paths, snippet_opt, span_lint, span_lint_and_sugg,
- span_lint_and_then, without_block_comments,
+ first_line_of_span, is_present_in_source, match_panic_def_id, snippet_opt, span_lint, span_lint_and_help,
+ span_lint_and_sugg, span_lint_and_then, without_block_comments,
};
use if_chain::if_chain;
-use rustc::lint::in_external_macro;
-use rustc::ty;
-use rustc_ast::ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
-use rustc_ast::util::lev_distance::find_best_match_for_name;
+use rustc_ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
use rustc_errors::Applicability;
use rustc_hir::{
Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind,
};
-use rustc_lint::{CheckLintNameResult, EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Span;
-use rustc_span::symbol::Symbol;
+use rustc_span::sym;
+use rustc_span::symbol::{Symbol, SymbolStr};
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.
/// **What it does:** Checks for `extern crate` and `use` items annotated with
/// lint attributes.
///
- /// This lint whitelists `#[allow(unused_imports)]`, `#[allow(deprecated)]` and
- /// `#[allow(unreachable_pub)]` on `use` items and `#[allow(unused_imports)]` on
+ /// This lint permits `#[allow(unused_imports)]`, `#[allow(deprecated)]`,
+ /// `#[allow(unreachable_pub)]`, `#[allow(clippy::wildcard_imports)]` and
+ /// `#[allow(clippy::enum_glob_use)]` on `use` items and `#[allow(unused_imports)]` on
/// `extern crate` items with a `#[macro_use]` attribute.
///
/// **Why is this bad?** Lint attributes have no effect on crate imports. Most
/// **Example:**
/// ```rust
/// // Good (as inner attribute)
- /// #![inline(always)]
+ /// #![allow(dead_code)]
///
/// fn this_is_fine() { }
///
/// // Bad
- /// #[inline(always)]
+ /// #[allow(dead_code)]
///
/// fn not_quite_good_code() { }
///
/// // Good (as outer attribute)
- /// #[inline(always)]
+ /// #[allow(dead_code)]
/// fn this_is_fine_too() { }
/// ```
pub EMPTY_LINE_AFTER_OUTER_ATTR,
}
declare_clippy_lint! {
- /// **What it does:** Checks for `allow`/`warn`/`deny`/`forbid` attributes with scoped clippy
- /// lints and if those lints exist in clippy. If there is an uppercase letter in the lint name
- /// (not the tool name) and a lowercase version of this lint exists, it will suggest to lowercase
- /// the lint name.
+ /// **What it does:** Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category.
///
- /// **Why is this bad?** A lint attribute with a mistyped lint name won't have an effect.
+ /// **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.
///
/// **Known problems:** None.
///
/// **Example:**
/// Bad:
/// ```rust
- /// #![warn(if_not_els)]
- /// #![deny(clippy::All)]
+ /// #![deny(clippy::restriction)]
/// ```
///
/// Good:
/// ```rust
- /// #![warn(if_not_else)]
- /// #![deny(clippy::all)]
+ /// #![deny(clippy::as_conversions)]
/// ```
- pub UNKNOWN_CLIPPY_LINTS,
+ pub BLANKET_CLIPPY_RESTRICTION_LINTS,
style,
- "unknown_lints for scoped Clippy lints"
+ "enabling the complete restriction group"
}
declare_clippy_lint! {
"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.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// Bad:
+ /// ```rust
+ /// #[cfg(linux)]
+ /// fn conditional() { }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #[cfg(target_os = "linux")]
+ /// fn conditional() { }
+ /// ```
+ ///
+ /// Or:
+ /// ```rust
+ /// #[cfg(unix)]
+ /// fn conditional() { }
+ /// ```
+ /// Check the [Rust Reference](https://doc.rust-lang.org/reference/conditional-compilation.html#target_os) for more details.
+ pub MISMATCHED_TARGET_OS,
+ correctness,
+ "usage of `cfg(operating_system)` instead of `cfg(target_os = \"operating_system\")`"
+}
+
declare_lint_pass!(Attributes => [
INLINE_ALWAYS,
DEPRECATED_SEMVER,
USELESS_ATTRIBUTE,
- EMPTY_LINE_AFTER_OUTER_ATTR,
- UNKNOWN_CLIPPY_LINTS,
+ BLANKET_CLIPPY_RESTRICTION_LINTS,
]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Attributes {
- fn check_attribute(&mut self, cx: &LateContext<'a, 'tcx>, attr: &'tcx Attribute) {
+impl<'tcx> LateLintPass<'tcx> for Attributes {
+ 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() {
- match &*ident.as_str() {
+ let ident = &*ident.as_str();
+ match ident {
"allow" | "warn" | "deny" | "forbid" => {
- check_clippy_lint_names(cx, items);
+ check_clippy_lint_names(cx, ident, items);
},
_ => {},
}
- if items.is_empty() || !attr.check_name(sym!(deprecated)) {
+ if items.is_empty() || !attr.has_name(sym::deprecated) {
return;
}
for item in items {
if_chain! {
if let NestedMetaItem::MetaItem(mi) = &item;
if let MetaItemKind::NameValue(lit) = &mi.kind;
- if mi.check_name(sym!(since));
+ if mi.has_name(sym::since);
then {
check_semver(cx, item.span(), lit);
}
}
}
- fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ 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, &item.attrs)
+ check_attrs(cx, item.span, item.ident.name, attrs)
}
match item.kind {
ItemKind::ExternCrate(..) | ItemKind::Use(..) => {
- let skip_unused_imports = item.attrs.iter().any(|attr| attr.check_name(sym!(macro_use)));
+ let skip_unused_imports = attrs.iter().any(|attr| attr.has_name(sym::macro_use));
- for attr in item.attrs {
+ for attr in attrs {
if in_external_macro(cx.sess(), attr.span) {
return;
}
if let Some(ident) = attr.ident() {
match &*ident.as_str() {
"allow" | "warn" | "deny" | "forbid" => {
- // whitelist `unused_imports`, `deprecated` and `unreachable_pub` for `use` items
+ // permit `unused_imports`, `deprecated`, `unreachable_pub`,
+ // `clippy::wildcard_imports`, and `clippy::enum_glob_use` for `use` items
// and `unused_imports` for `extern crate` items with `macro_use`
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::deprecated)
|| is_word(lint, sym!(unreachable_pub))
|| is_word(lint, sym!(unused))
+ || extract_clippy_lint(lint)
+ .map_or(false, |s| s == "wildcard_imports")
+ || extract_clippy_lint(lint).map_or(false, |s| s == "enum_glob_use")
{
return;
}
USELESS_ATTRIBUTE,
line_span,
"useless lint attribute",
- |db| {
+ |diag| {
sugg = sugg.replacen("#[", "#![", 1);
- db.span_suggestion(
+ diag.span_suggestion(
line_span,
"if you just forgot a `!`, use",
sugg,
}
}
- fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx ImplItem<'_>) {
+ 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, &item.attrs)
+ check_attrs(cx, item.span, item.ident.name, cx.tcx.hir().attrs(item.hir_id()))
}
}
- fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem<'_>) {
+ 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, &item.attrs)
+ 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<SymbolStr> {
+ if_chain! {
+ if let Some(meta_item) = lint.meta_item();
+ if meta_item.path.segments.len() > 1;
+ if let tool_name = meta_item.path.segments[0].ident;
+ if tool_name.name == sym::clippy;
+ let lint_name = meta_item.path.segments.last().unwrap().ident.name;
+ then {
+ return Some(lint_name.as_str());
}
}
+ None
}
-#[allow(clippy::single_match_else)]
-fn check_clippy_lint_names(cx: &LateContext<'_, '_>, items: &[NestedMetaItem]) {
- let lint_store = cx.lints();
+fn check_clippy_lint_names(cx: &LateContext<'_>, ident: &str, items: &[NestedMetaItem]) {
for lint in items {
- if_chain! {
- if let Some(meta_item) = lint.meta_item();
- if meta_item.path.segments.len() > 1;
- if let tool_name = meta_item.path.segments[0].ident;
- if tool_name.as_str() == "clippy";
- let name = meta_item.path.segments.last().unwrap().ident.name;
- if let CheckLintNameResult::Tool(Err((None, _))) = lint_store.check_lint_name(
- &name.as_str(),
- Some(tool_name.name),
- );
- then {
- span_lint_and_then(
+ if let Some(lint_name) = extract_clippy_lint(lint) {
+ if lint_name == "restriction" && ident != "allow" {
+ span_lint_and_help(
cx,
- UNKNOWN_CLIPPY_LINTS,
+ BLANKET_CLIPPY_RESTRICTION_LINTS,
lint.span(),
- &format!("unknown clippy lint: clippy::{}", name),
- |db| {
- let name_lower = name.as_str().to_lowercase();
- let symbols = lint_store.get_lints().iter().map(
- |l| Symbol::intern(&l.name_lower())
- ).collect::<Vec<_>>();
- let sugg = find_best_match_for_name(
- symbols.iter(),
- &format!("clippy::{}", name_lower),
- None,
- );
- if name.as_str().chars().any(char::is_uppercase)
- && lint_store.find_lints(&format!("clippy::{}", name_lower)).is_ok() {
- db.span_suggestion(
- lint.span(),
- "lowercase the lint name",
- format!("clippy::{}", name_lower),
- Applicability::MachineApplicable,
- );
- } else if let Some(sugg) = sugg {
- db.span_suggestion(
- lint.span(),
- "did you mean",
- sugg.to_string(),
- Applicability::MachineApplicable,
- );
- }
- }
+ "restriction lints are not meant to be all enabled",
+ None,
+ "try enabling only the lints you really need",
);
}
- };
+ }
}
}
-fn is_relevant_item(cx: &LateContext<'_, '_>, item: &Item<'_>) -> bool {
+fn is_relevant_item(cx: &LateContext<'_>, item: &Item<'_>) -> bool {
if let ItemKind::Fn(_, _, eid) = item.kind {
- is_relevant_expr(cx, cx.tcx.body_tables(eid), &cx.tcx.hir().body(eid).value)
+ 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 {
+fn is_relevant_impl(cx: &LateContext<'_>, item: &ImplItem<'_>) -> bool {
match item.kind {
- ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.body_tables(eid), &cx.tcx.hir().body(eid).value),
+ 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 {
+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.body_tables(eid), &cx.tcx.hir().body(eid).value)
+ is_relevant_expr(cx, cx.tcx.typeck_body(eid), &cx.tcx.hir().body(eid).value)
},
_ => false,
}
}
-fn is_relevant_block(cx: &LateContext<'_, '_>, tables: &ty::TypeckTables<'_>, block: &Block<'_>) -> bool {
- if let Some(stmt) = block.stmts.first() {
- match &stmt.kind {
+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, tables, expr),
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, typeck_results, expr),
_ => false,
- }
- } else {
- block.expr.as_ref().map_or(false, |e| is_relevant_expr(cx, tables, e))
- }
+ },
+ )
}
-fn is_relevant_expr(cx: &LateContext<'_, '_>, tables: &ty::TypeckTables<'_>, expr: &Expr<'_>) -> bool {
+fn is_relevant_expr(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, expr: &Expr<'_>) -> bool {
match &expr.kind {
- ExprKind::Block(block, _) => is_relevant_block(cx, tables, block),
- ExprKind::Ret(Some(e)) => is_relevant_expr(cx, tables, e),
+ 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,
ExprKind::Call(path_expr, _) => {
if let ExprKind::Path(qpath) = &path_expr.kind {
- if let Some(fun_id) = tables.qpath_res(qpath, path_expr.hir_id).opt_def_id() {
- !match_def_path(cx, fun_id, &paths::BEGIN_PANIC)
- } else {
- true
- }
+ typeck_results
+ .qpath_res(qpath, path_expr.hir_id)
+ .opt_def_id()
+ .map_or(true, |fun_id| !match_panic_def_id(cx, fun_id))
} else {
true
}
}
}
-fn check_attrs(cx: &LateContext<'_, '_>, span: Span, name: Name, attrs: &[Attribute]) {
+fn check_attrs(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribute]) {
if span.from_expansion() {
return;
}
for attr in attrs {
- let attr_item = if let AttrKind::Normal(ref attr) = attr.kind {
- attr
- } else {
- continue;
- };
-
- if attr.style == AttrStyle::Outer {
- if attr_item.args.inner_tokens().is_empty() || !is_present_in_source(cx, attr.span) {
- return;
- }
-
- let begin_of_attr_to_item = Span::new(attr.span.lo(), span.lo(), span.ctxt());
- let end_of_attr_to_item = Span::new(attr.span.hi(), span.lo(), span.ctxt());
-
- if let Some(snippet) = snippet_opt(cx, end_of_attr_to_item) {
- let lines = snippet.split('\n').collect::<Vec<_>>();
- 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?",
- );
- }
- }
- }
-
if let Some(values) = attr.meta_item_list() {
- if values.len() != 1 || !attr.check_name(sym!(inline)) {
+ if values.len() != 1 || !attr.has_name(sym::inline) {
continue;
}
- if is_word(&values[0], sym!(always)) {
+ if is_word(&values[0], sym::always) {
span_lint(
cx,
INLINE_ALWAYS,
}
}
-fn check_semver(cx: &LateContext<'_, '_>, span: Span, lit: &Lit) {
+fn check_semver(cx: &LateContext<'_>, span: Span, lit: &Lit) {
if let LitKind::Str(is, _) = lit.kind {
if Version::parse(&is.as_str()).is_ok() {
return;
fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool {
if let NestedMetaItem::MetaItem(mi) = &nmi {
- mi.is_word() && mi.check_name(expected)
+ mi.is_word() && mi.has_name(expected)
} else {
false
}
}
-declare_lint_pass!(DeprecatedCfgAttribute => [DEPRECATED_CFG_ATTR]);
+declare_lint_pass!(EarlyAttributes => [
+ DEPRECATED_CFG_ATTR,
+ MISMATCHED_TARGET_OS,
+ EMPTY_LINE_AFTER_OUTER_ATTR,
+]);
+
+impl EarlyLintPass for EarlyAttributes {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
+ check_empty_line_after_outer_attr(cx, item);
+ }
-impl EarlyLintPass for DeprecatedCfgAttribute {
fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
- if_chain! {
- // check cfg_attr
- if attr.check_name(sym!(cfg_attr));
- if let Some(items) = attr.meta_item_list();
- if items.len() == 2;
- // check for `rustfmt`
- if let Some(feature_item) = items[0].meta_item();
- if feature_item.check_name(sym!(rustfmt));
- // check for `rustfmt_skip` and `rustfmt::skip`
- if let Some(skip_item) = &items[1].meta_item();
- if skip_item.check_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
- if let AttrStyle::Outer = attr.style;
- then {
- 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,
- );
+ check_deprecated_cfg_attr(cx, attr);
+ check_mismatched_target_os(cx, attr);
+ }
+}
+
+fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
+ for attr in &item.attrs {
+ let attr_item = if let AttrKind::Normal(ref attr, _) = attr.kind {
+ attr
+ } else {
+ return;
+ };
+
+ if attr.style == AttrStyle::Outer {
+ if attr_item.args.inner_tokens().is_empty() || !is_present_in_source(cx, attr.span) {
+ return;
+ }
+
+ let begin_of_attr_to_item = Span::new(attr.span.lo(), item.span.lo(), item.span.ctxt());
+ let end_of_attr_to_item = Span::new(attr.span.hi(), item.span.lo(), item.span.ctxt());
+
+ if let Some(snippet) = snippet_opt(cx, end_of_attr_to_item) {
+ let lines = snippet.split('\n').collect::<Vec<_>>();
+ 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?",
+ );
+ }
}
}
}
}
+
+fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute) {
+ if_chain! {
+ // check cfg_attr
+ if attr.has_name(sym::cfg_attr);
+ if let Some(items) = attr.meta_item_list();
+ if items.len() == 2;
+ // check for `rustfmt`
+ if let Some(feature_item) = items[0].meta_item();
+ if feature_item.has_name(sym::rustfmt);
+ // check for `rustfmt_skip` and `rustfmt::skip`
+ if let Some(skip_item) = &items[1].meta_item();
+ if 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
+ if let AttrStyle::Outer = attr.style;
+ then {
+ 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,
+ );
+ }
+ }
+}
+
+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_chain! {
+ if let Some(ident) = meta.ident();
+ if let Some(os) = find_os(&*ident.name.as_str());
+ then {
+ mismatched.push((os, ident.span));
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+ }
+
+ mismatched
+ }
+
+ if_chain! {
+ if attr.has_name(sym::cfg);
+ if let Some(list) = attr.meta_item_list();
+ let mismatched = find_mismatched_target_os(&list);
+ if !mismatched.is_empty();
+ then {
+ 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;
+ }
+ }
+ });
+ }
+ }
+}