]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/attrs.rs
Auto merge of #92252 - GuillaumeGomez:update-pulldown, r=camelid,xFrednet
[rust.git] / clippy_lints / src / attrs.rs
index 3cef8d2a78bf727eb6e99e0414b29ca1f216ac48..0629674307ba77dd86ad61b4f042a1a726cdf8dd 100644 (file)
@@ -1,8 +1,9 @@
 //! checks for attributes
 
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
-use clippy_utils::match_panic_def_id;
+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, match_panic_def_id, meets_msrv};
 use if_chain::if_chain;
 use rustc_ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
 use rustc_errors::Applicability;
 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_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, SymbolStr};
+use rustc_span::symbol::Symbol;
 use semver::Version;
 
 static UNIX_SYSTEMS: &[&str] = &[
 static NON_UNIX_SYSTEMS: &[&str] = &["hermit", "none", "wasi"];
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for items annotated with `#[inline(always)]`,
+    /// ### 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
+    /// ### 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.
     ///
     /// 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
+    /// ### 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:**
+    /// ### 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
+    /// ### What it does
+    /// Checks for `extern crate` and `use` items annotated with
     /// lint attributes.
     ///
     /// This lint permits `#[allow(unused_imports)]`, `#[allow(deprecated)]`,
     /// `#[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
+    /// ### Why is this bad?
+    /// Lint attributes have no effect on crate imports. Most
     /// likely a `!` was forgotten.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// ```ignore
     /// // Bad
     /// #[deny(dead_code)]
     /// #[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`
+    /// ### 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
+    /// ### 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:**
+    /// ### Example
     /// ```rust
     /// #[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
+    /// ### What it does
+    /// Checks for empty lines after outer attributes
     ///
-    /// **Why is this bad?**
+    /// ### 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.
+    /// ### 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:**
+    /// ### Example
     /// ```rust
     /// // Good (as inner attribute)
     /// #![allow(dead_code)]
     /// #[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 `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category.
+    /// ### 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.
+    /// ### 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:**
+    /// ### Example
     /// Bad:
     /// ```rust
     /// #![deny(clippy::restriction)]
     /// ```rust
     /// #![deny(clippy::as_conversions)]
     /// ```
+    #[clippy::version = "1.47.0"]
     pub BLANKET_CLIPPY_RESTRICTION_LINTS,
-    style,
+    suspicious,
     "enabling the complete restriction group"
 }
 
 declare_clippy_lint! {
-    /// **What it does:** Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it
+    /// ### 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))
+    /// ### 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
+    /// ### 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:**
-    ///
+    /// ### Example
     /// Bad:
     /// ```rust
     /// #[cfg_attr(rustfmt, rustfmt_skip)]
     /// #[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.
+    /// ### 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
+    /// ### 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:**
-    ///
+    /// ### Example
     /// Bad:
     /// ```rust
     /// #[cfg(linux)]
     /// 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\")`"
@@ -250,12 +265,8 @@ 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() {
-                let ident = &*ident.as_str();
-                match ident {
-                    "allow" | "warn" | "deny" | "forbid" => {
-                        check_clippy_lint_names(cx, ident, items);
-                    },
-                    _ => {},
+                if is_lint_level(ident.name) {
+                    check_clippy_lint_names(cx, ident.name, items);
                 }
                 if items.is_empty() || !attr.has_name(sym::deprecated) {
                     return;
@@ -277,7 +288,7 @@ fn check_attribute(&mut self, cx: &LateContext<'tcx>, attr: &'tcx Attribute) {
     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)
+            check_attrs(cx, item.span, item.ident.name, attrs);
         }
         match item.kind {
             ItemKind::ExternCrate(..) | ItemKind::Use(..) => {
@@ -288,60 +299,56 @@ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
                         return;
                     }
                     if let Some(lint_list) = &attr.meta_item_list() {
-                        if let Some(ident) = attr.ident() {
-                            match &*ident.as_str() {
-                                "allow" | "warn" | "deny" | "forbid" => {
-                                    // 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 == "wildcard_imports")
-                                                    || extract_clippy_lint(lint).map_or(false, |s| s == "enum_glob_use")
-                                                {
-                                                    return;
-                                                }
-                                            },
-                                            ItemKind::ExternCrate(..) => {
-                                                if is_word(lint, sym!(unused_imports)) && skip_unused_imports {
-                                                    return;
-                                                }
-                                                if is_word(lint, sym!(unused_extern_crates)) {
-                                                    return;
-                                                }
-                                            },
-                                            _ => {},
+                        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;
+                                        }
+                                    },
+                                    ItemKind::ExternCrate(..) => {
+                                        if is_word(lint, sym!(unused_imports)) && skip_unused_imports {
+                                            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,
+                                        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,
-                                                "useless lint attribute",
-                                                |diag| {
-                                                    sugg = sugg.replacen("#[", "#![", 1);
-                                                    diag.span_suggestion(
-                                                        line_span,
-                                                        "if you just forgot a `!`, use",
-                                                        sugg,
-                                                        Applicability::MaybeIncorrect,
-                                                    );
-                                                },
+                                                "if you just forgot a `!`, use",
+                                                sugg,
+                                                Applicability::MaybeIncorrect,
                                             );
-                                        }
-                                    }
-                                },
-                                _ => {},
+                                        },
+                                    );
+                                }
                             }
                         }
                     }
@@ -353,36 +360,36 @@ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
 
     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()))
+            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()))
+            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> {
+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;
-        let lint_name = meta_item.path.segments.last().unwrap().ident.name;
         then {
-            return Some(lint_name.as_str());
+            let lint_name = meta_item.path.segments.last().unwrap().ident.name;
+            return Some(lint_name);
         }
     }
     None
 }
 
-fn check_clippy_lint_names(cx: &LateContext<'_>, ident: &str, items: &[NestedMetaItem]) {
+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 == "restriction" && ident != "allow" {
+            if lint_name.as_str() == "restriction" && name != sym::allow {
                 span_lint_and_help(
                     cx,
                     BLANKET_CLIPPY_RESTRICTION_LINTS,
@@ -481,7 +488,7 @@ fn check_attrs(cx: &LateContext<'_>, span: Span, name: Symbol, attrs: &[Attribut
 
 fn check_semver(cx: &LateContext<'_>, span: Span, lit: &Lit) {
     if let LitKind::Str(is, _) = lit.kind {
-        if Version::parse(&is.as_str()).is_ok() {
+        if Version::parse(is.as_str()).is_ok() {
             return;
         }
     }
@@ -501,7 +508,11 @@ fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool {
     }
 }
 
-declare_lint_pass!(EarlyAttributes => [
+pub struct EarlyAttributes {
+    pub msrv: Option<RustcVersion>,
+}
+
+impl_lint_pass!(EarlyAttributes => [
     DEPRECATED_CFG_ATTR,
     MISMATCHED_TARGET_OS,
     EMPTY_LINE_AFTER_OUTER_ATTR,
@@ -513,9 +524,11 @@ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
     }
 
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
-        check_deprecated_cfg_attr(cx, attr);
+        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) {
@@ -531,8 +544,8 @@ fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::It
                 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());
+            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<_>>();
@@ -552,8 +565,9 @@ fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::It
     }
 }
 
-fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &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();
@@ -567,7 +581,7 @@ fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute) {
             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;
+        if attr.style == AttrStyle::Outer;
         then {
             span_lint_and_sugg(
                 cx,
@@ -602,12 +616,12 @@ fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> {
             if let NestedMetaItem::MetaItem(meta) = item {
                 match &meta.kind {
                     MetaItemKind::List(list) => {
-                        mismatched.extend(find_mismatched_target_os(&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());
+                            if let Some(os) = find_os(ident.name.as_str());
                             then {
                                 mismatched.push((os, ident.span));
                             }
@@ -629,7 +643,7 @@ fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> {
         then {
             let mess = "operating system used in target family position";
 
-            span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, &mess, |diag| {
+            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;
@@ -647,3 +661,7 @@ fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> {
         }
     }
 }
+
+fn is_lint_level(symbol: Symbol) -> bool {
+    matches!(symbol, sym::allow | sym::warn | sym::deny | sym::forbid)
+}