modify code

[rust.git] / clippy_lints / src / single_component_path_imports.rs

diff --git a/clippy_lints/src/single_component_path_imports.rs b/clippy_lints/src/single_component_path_imports.rs
index 6104103580e989fe56530b3bd767b56ac2b2af7a..961cdb317e76cd0abd0c26a240567533869f72c5 100644 (file)
--- a/clippy_lints/src/single_component_path_imports.rs
+++ b/clippy_lints/src/single_component_path_imports.rs
@@ -1,21 +1,19 @@
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
-use clippy_utils::in_macro;
-use rustc_ast::{ptr::P, Crate, Item, ItemKind, ModKind, UseTreeKind};
+use rustc_ast::{ptr::P, Crate, Item, ItemKind, MacroDef, ModKind, UseTreeKind, VisibilityKind};
 use rustc_errors::Applicability;
-use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{edition::Edition, symbol::kw, Span, Symbol};
 
 declare_clippy_lint! {
-    /// **What it does:** Checking for imports with single component use path.
+    /// ### What it does
+    /// Checking for imports with single component use path.
     ///
-    /// **Why is this bad?** Import with single component use path such as `use cratename;`
+    /// ### Why is this bad?
+    /// Import with single component use path such as `use cratename;`
     /// is not necessary, and thus should be removed.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
-    ///
+    /// ### Example
     /// ```rust,ignore
     /// use regex;
     ///
@@ -29,6 +27,7 @@
     ///     regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
     /// }
     /// ```
+    #[clippy::version = "1.43.0"]
     pub SINGLE_COMPONENT_PATH_IMPORTS,
     style,
     "imports with single component path are redundant"
@@ -38,7 +37,7 @@
 
 impl EarlyLintPass for SingleComponentPathImports {
     fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &Crate) {
-        if cx.sess.opts.edition < Edition::Edition2018 {
+        if cx.sess().opts.edition < Edition::Edition2018 {
             return;
         }
         check_mod(cx, &krate.items);
@@ -60,8 +59,21 @@ fn check_mod(cx: &EarlyContext<'_>, items: &[P<Item>]) {
     // ```
     let mut single_use_usages = Vec::new();
 
+    // keep track of macros defined in the module as we don't want it to trigger on this (#7106)
+    // ```rust,ignore
+    // macro_rules! foo { () => {} };
+    // pub(crate) use foo;
+    // ```
+    let mut macros = Vec::new();
+
     for item in items {
-        track_uses(cx, &item, &mut imports_reused_with_self, &mut single_use_usages);
+        track_uses(
+            cx,
+            item,
+            &mut imports_reused_with_self,
+            &mut single_use_usages,
+            &mut macros,
+        );
     }
 
     for single_use in &single_use_usages {
@@ -96,23 +108,32 @@ fn track_uses(
     item: &Item,
     imports_reused_with_self: &mut Vec<Symbol>,
     single_use_usages: &mut Vec<(Symbol, Span, bool)>,
+    macros: &mut Vec<Symbol>,
 ) {
-    if in_macro(item.span) || item.vis.kind.is_pub() {
+    if item.span.from_expansion() || item.vis.kind.is_pub() {
         return;
     }
 
     match &item.kind {
         ItemKind::Mod(_, ModKind::Loaded(ref items, ..)) => {
-            check_mod(cx, &items);
+            check_mod(cx, items);
+        },
+        ItemKind::MacroDef(MacroDef { macro_rules: true, .. }) => {
+            macros.push(item.ident.name);
         },
         ItemKind::Use(use_tree) => {
             let segments = &use_tree.prefix.segments;
 
+            let should_report =
+                |name: &Symbol| !macros.contains(name) || matches!(item.vis.kind, VisibilityKind::Inherited);
+
             // keep track of `use some_module;` usages
             if segments.len() == 1 {
                 if let UseTreeKind::Simple(None, _, _) = use_tree.kind {
-                    let ident = &segments[0].ident;
-                    single_use_usages.push((ident.name, item.span, true));
+                    let name = segments[0].ident.name;
+                    if should_report(&name) {
+                        single_use_usages.push((name, item.span, true));
+                    }
                 }
                 return;
             }
@@ -124,8 +145,10 @@ fn track_uses(
                         let segments = &tree.0.prefix.segments;
                         if segments.len() == 1 {
                             if let UseTreeKind::Simple(None, _, _) = tree.0.kind {
-                                let ident = &segments[0].ident;
-                                single_use_usages.push((ident.name, tree.0.span, false));
+                                let name = segments[0].ident.name;
+                                if should_report(&name) {
+                                    single_use_usages.push((name, tree.0.span, false));
+                                }
                             }
                         }
                     }