//! checks for attributes
-use reexport::*;
-use rustc::lint::*;
-use rustc::hir::*;
-use rustc::ty::{self, TyCtxt};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::macros::{is_panic, macro_backtrace};
+use clippy_utils::msrvs;
+use clippy_utils::source::{first_line_of_span, is_present_in_source, snippet_opt, without_block_comments};
+use clippy_utils::{extract_msrv_attr, meets_msrv};
+use if_chain::if_chain;
+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::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+use rustc_span::symbol::Symbol;
use semver::Version;
-use syntax::ast::{Attribute, AttrStyle, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
-use syntax::codemap::Span;
-use utils::{in_macro, match_def_path, opt_def_id, paths, snippet_opt, span_lint, span_lint_and_then};
-
-/// **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:**
-/// ```rust
-/// #[inline(always)]
-/// fn not_quite_hot_code(..) { ... }
-/// ```
-declare_lint! {
+
+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,
- Warn,
+ pedantic,
"use of `#[inline(always)]`"
}
-/// **What it does:** Checks for `extern crate` and `use` items annotated with
-/// lint attributes
-///
-/// **Why is this bad?** Lint attributes have no effect on crate imports. Most
-/// likely a `!` was
-/// forgotten
-///
-/// **Known problems:** Technically one might allow `unused_import` on a `use`
-/// item,
-/// but it's easier to remove the unused item.
-///
-/// **Example:**
-/// ```rust
-/// #[deny(dead_code)]
-/// extern crate foo;
-/// #[allow(unused_import)]
-/// use foo::bar;
-/// ```
-declare_lint! {
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `extern crate` and `use` items annotated with
+ /// lint attributes.
+ ///
+ /// 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
+ /// likely a `!` was forgotten.
+ ///
+ /// ### Example
+ /// ```ignore
+ /// // Bad
+ /// #[deny(dead_code)]
+ /// extern crate foo;
+ /// #[forbid(dead_code)]
+ /// use foo::bar;
+ ///
+ /// // Ok
+ /// #[allow(unused_imports)]
+ /// use foo::baz;
+ /// #[allow(unused_imports)]
+ /// #[macro_use]
+ /// extern crate baz;
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
pub USELESS_ATTRIBUTE,
- Warn,
+ correctness,
"use of lint attributes on `extern crate` items"
}
-/// **What it does:** Checks for `#[deprecated]` annotations with a `since`
-/// field that is not a valid semantic version.
-///
-/// **Why is this bad?** For checking the version of the deprecation, it must be
-/// a valid semver. Failing that, the contained information is useless.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// #[deprecated(since = "forever")]
-/// fn something_else(..) { ... }
-/// ```
-declare_lint! {
+declare_clippy_lint! {
+ /// ### What it does
+ /// Checks for `#[deprecated]` annotations with a `since`
+ /// field that is not a valid semantic version.
+ ///
+ /// ### 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
+ /// ```rust
+ /// #[deprecated(since = "forever")]
+ /// fn something_else() { /* ... */ }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
pub DEPRECATED_SEMVER,
- Warn,
+ correctness,
"use of `#[deprecated(since = \"x\")]` where x is not semver"
}
-/// **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:** None
-///
-/// **Example:**
-/// ```rust
-/// // Bad
-/// #[inline(always)]
-///
-/// fn not_quite_good_code(..) { ... }
-///
-/// // Good (as inner attribute)
-/// #![inline(always)]
-///
-/// fn this_is_fine(..) { ... }
-///
-/// // Good (as outer attribute)
-/// #[inline(always)]
-/// fn this_is_fine_too(..) { ... }
-/// ```
-declare_lint! {
+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
+ /// ```rust
+ /// // Good (as inner attribute)
+ /// #![allow(dead_code)]
+ ///
+ /// fn this_is_fine() { }
+ ///
+ /// // Bad
+ /// #[allow(dead_code)]
+ ///
+ /// fn not_quite_good_code() { }
+ ///
+ /// // Good (as outer attribute)
+ /// #[allow(dead_code)]
+ /// fn this_is_fine_too() { }
+ /// ```
+ #[clippy::version = "pre 1.29.0"]
pub EMPTY_LINE_AFTER_OUTER_ATTR,
- Warn,
+ nursery,
"empty line after outer attribute"
}
-#[derive(Copy, Clone)]
-pub struct AttrPass;
+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
+ /// Bad:
+ /// ```rust
+ /// #![deny(clippy::restriction)]
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #![deny(clippy::as_conversions)]
+ /// ```
+ #[clippy::version = "1.47.0"]
+ pub BLANKET_CLIPPY_RESTRICTION_LINTS,
+ suspicious,
+ "enabling the complete restriction group"
+}
-impl LintPass for AttrPass {
- fn get_lints(&self) -> LintArray {
- lint_array!(INLINE_ALWAYS, DEPRECATED_SEMVER, USELESS_ATTRIBUTE, EMPTY_LINE_AFTER_OUTER_ATTR)
- }
+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
+ /// Bad:
+ /// ```rust
+ /// #[cfg_attr(rustfmt, rustfmt_skip)]
+ /// fn main() { }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #[rustfmt::skip]
+ /// fn main() { }
+ /// ```
+ #[clippy::version = "1.32.0"]
+ pub DEPRECATED_CFG_ATTR,
+ complexity,
+ "usage of `cfg_attr(rustfmt)` instead of tool attributes"
}
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AttrPass {
- fn check_attribute(&mut self, cx: &LateContext<'a, 'tcx>, attr: &'tcx Attribute) {
- if let Some(ref items) = attr.meta_item_list() {
- if items.is_empty() || attr.name().map_or(true, |n| n != "deprecated") {
- return;
- }
- for item in items {
- if_chain! {
- if let NestedMetaItemKind::MetaItem(ref mi) = item.node;
- if let MetaItemKind::NameValue(ref lit) = mi.node;
- if mi.name() == "since";
- then {
- check_semver(cx, item.span, lit);
+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
+ /// 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.
+ #[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
+ /// Bad:
+ /// ```rust
+ /// #![feature(lint_reasons)]
+ ///
+ /// #![allow(clippy::some_lint)]
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #![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_lint_pass!(Attributes => [
+ ALLOW_ATTRIBUTES_WITHOUT_REASON,
+ INLINE_ALWAYS,
+ DEPRECATED_SEMVER,
+ USELESS_ATTRIBUTE,
+ BLANKET_CLIPPY_RESTRICTION_LINTS,
+]);
+
+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() {
+ if is_lint_level(ident.name) {
+ 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_chain! {
+ if let NestedMetaItem::MetaItem(mi) = &item;
+ if let MetaItemKind::NameValue(lit) = &mi.kind;
+ 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) {
- if is_relevant_item(cx.tcx, item) {
- check_attrs(cx, item.span, &item.name, &item.attrs)
+ 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.node {
- ItemExternCrate(_) | ItemUse(_, _) => {
- for attr in &item.attrs {
- if let Some(ref lint_list) = attr.meta_item_list() {
- if let Some(name) = attr.name() {
- match &*name.as_str() {
- "allow" | "warn" | "deny" | "forbid" => {
- // whitelist `unused_imports` and `deprecated`
- for lint in lint_list {
- if is_word(lint, "unused_imports") || is_word(lint, "deprecated") {
- if let ItemUse(_, _) = item.node {
- return;
- }
+ 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)) {
+ // 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!(unreachable_pub))
+ || is_word(lint, sym!(unused))
+ || extract_clippy_lint(lint)
+ .map_or(false, |s| s.as_str() == "wildcard_imports")
+ || extract_clippy_lint(lint)
+ .map_or(false, |s| s.as_str() == "enum_glob_use")
+ {
+ return;
}
- }
- if let Some(mut sugg) = snippet_opt(cx, attr.span) {
- if sugg.len() > 1 {
- span_lint_and_then(
- cx,
- USELESS_ATTRIBUTE,
- attr.span,
- "useless lint attribute",
- |db| {
- sugg.insert(1, '!');
- db.span_suggestion(
- attr.span,
- "if you just forgot a `!`, use",
- sugg,
- );
- },
- );
+ },
+ 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<'a, 'tcx>, item: &'tcx ImplItem) {
- if is_relevant_impl(cx.tcx, item) {
- check_attrs(cx, item.span, &item.name, &item.attrs)
+ 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<Symbol> {
+ 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;
+ then {
+ let lint_name = meta_item.path.segments.last().unwrap().ident.name;
+ return Some(lint_name);
}
}
+ None
+}
- fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem) {
- if is_relevant_trait(cx.tcx, item) {
- check_attrs(cx, item.span, &item.name, &item.attrs)
+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(),
+ "restriction lints are not meant to be all enabled",
+ None,
+ "try enabling only the lints you really need",
+ );
+ }
}
}
}
-fn is_relevant_item(tcx: TyCtxt, item: &Item) -> bool {
- if let ItemFn(_, _, _, _, _, eid) = item.node {
- is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir.body(eid).value)
+fn check_lint_reason(cx: &LateContext<'_>, name: Symbol, items: &[NestedMetaItem], attr: &'_ Attribute) {
+ // Check for the feature
+ if !cx.tcx.sess.features_untracked().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;
+ }
+
+ 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(tcx: TyCtxt, item: &ImplItem) -> bool {
- match item.node {
- ImplItemKind::Method(_, eid) => is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir.body(eid).value),
+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(tcx: TyCtxt, item: &TraitItem) -> bool {
- match item.node {
- TraitItemKind::Method(_, TraitMethod::Required(_)) => true,
- TraitItemKind::Method(_, TraitMethod::Provided(eid)) => {
- is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir.body(eid).value)
+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(tcx: TyCtxt, tables: &ty::TypeckTables, block: &Block) -> bool {
- if let Some(stmt) = block.stmts.first() {
- match stmt.node {
- StmtDecl(_, _) => true,
- StmtExpr(ref expr, _) | StmtSemi(ref expr, _) => is_relevant_expr(tcx, tables, expr),
- }
- } else {
+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(tcx, tables, e))
- }
+ .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(tcx: TyCtxt, tables: &ty::TypeckTables, expr: &Expr) -> bool {
- match expr.node {
- ExprBlock(ref block) => is_relevant_block(tcx, tables, block),
- ExprRet(Some(ref e)) => is_relevant_expr(tcx, tables, e),
- ExprRet(None) | ExprBreak(_, None) => false,
- ExprCall(ref path_expr, _) => if let ExprPath(ref qpath) = path_expr.node {
- if let Some(fun_id) = opt_def_id(tables.qpath_def(qpath, path_expr.hir_id)) {
- !match_def_path(tcx, fun_id, &paths::BEGIN_PANIC)
- } else {
- true
- }
- } else {
- true
- },
+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: &Name, attrs: &[Attribute]) {
- if in_macro(span) {
+fn check_attrs(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribute]) {
+ if span.from_expansion() {
return;
}
for attr in attrs {
- if attr.is_sugared_doc {
- return;
- }
- if attr.style == AttrStyle::Outer {
- if !is_present_in_source(cx, attr.span) {
- return;
- }
-
- let attr_to_item_span = Span::new(attr.span.lo(), span.lo(), span.ctxt());
-
- if let Some(snippet) = snippet_opt(cx, attr_to_item_span) {
- let lines = snippet.split('\n').collect::<Vec<_>>();
- if lines.iter().filter(|l| l.trim().is_empty()).count() > 1 {
- span_lint(
- cx,
- EMPTY_LINE_AFTER_OUTER_ATTR,
- attr_to_item_span,
- "Found an empty line after an outer attribute. Perhaps you forgot to add a '!' to make it an inner attribute?"
- );
-
- }
- }
- }
-
- if let Some(ref values) = attr.meta_item_list() {
- if values.len() != 1 || attr.name().map_or(true, |n| n != "inline") {
+ if let Some(values) = attr.meta_item_list() {
+ if values.len() != 1 || !attr.has_name(sym::inline) {
continue;
}
- if is_word(&values[0], "always") {
+ if is_word(&values[0], sym::always) {
span_lint(
cx,
INLINE_ALWAYS,
}
}
-fn check_semver(cx: &LateContext, span: Span, lit: &Lit) {
- if let LitKind::Str(ref is, _) = lit.node {
- if Version::parse(&is.as_str()).is_ok() {
+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: &str) -> bool {
- if let NestedMetaItemKind::MetaItem(ref mi) = nmi.node {
- mi.is_word() && mi.name() == expected
+fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool {
+ if let NestedMetaItem::MetaItem(mi) = &nmi {
+ mi.is_word() && mi.has_name(expected)
} else {
false
}
}
-// If the snippet is empty, it's an attribute that was inserted during macro
-// expansion and we want to ignore those, because they could come from external
-// sources that the user has no control over.
-// For some reason these attributes don't have any expansion info on them, so
-// we have to check it this way until there is a better way.
-fn is_present_in_source(cx: &LateContext, span: Span) -> bool {
- if let Some(snippet) = snippet_opt(cx, span) {
- if snippet.is_empty() {
- return false;
+pub struct EarlyAttributes {
+ pub msrv: Option<RustcVersion>,
+}
+
+impl_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);
+ }
+
+ fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
+ check_deprecated_cfg_attr(cx, attr, self.msrv);
+ check_mismatched_target_os(cx, attr);
+ }
+
+ extract_msrv_attr!(EarlyContext);
+}
+
+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(), item.span.parent());
+ let end_of_attr_to_item = Span::new(attr.span.hi(), item.span.lo(), item.span.ctxt(), item.span.parent());
+
+ 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, msrv: Option<RustcVersion>) {
+ if_chain! {
+ if meets_msrv(msrv.as_ref(), &msrvs::TOOL_ATTRIBUTES);
+ // 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 attr.style == AttrStyle::Outer;
+ 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));
+ }
+ }
+ },
+ MetaItemKind::NameValue(..) => {},
+ }
+ }
}
+
+ mismatched
}
- true
+
+ 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;
+ }
+ }
+ });
+ }
+ }
+}
+
+fn is_lint_level(symbol: Symbol) -> bool {
+ matches!(symbol, sym::allow | sym::expect | sym::warn | sym::deny | sym::forbid)
}
projects / rustc.git / blobdiff