]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/attrs.rs
Rustup
[rust.git] / clippy_lints / src / attrs.rs
index 417ddbe8c12bb95c36aa8c39d6a2fdc24dfd1a07..b9d8976b28b4f0ce72face771ca2f1b5b3021df2 100644 (file)
@@ -1,13 +1,16 @@
 //! checks for attributes
 
-use reexport::*;
-use rustc::lint::*;
+use crate::reexport::*;
+use crate::utils::{
+    in_macro, last_line_of_span, match_def_path, opt_def_id, paths, snippet_opt, span_lint, span_lint_and_then,
+    without_block_comments,
+};
 use rustc::hir::*;
+use rustc::lint::*;
 use rustc::ty::{self, TyCtxt};
 use semver::Version;
-use syntax::ast::{Attribute, AttrStyle, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
+use syntax::ast::{AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
 use syntax::codemap::Span;
-use utils::{in_macro, last_line_of_span, 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.
@@ -29,9 +32,9 @@
 /// #[inline(always)]
 /// fn not_quite_hot_code(..) { ... }
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub INLINE_ALWAYS,
-    Warn,
+    pedantic,
     "use of `#[inline(always)]`"
 }
 
@@ -53,9 +56,9 @@
 /// #[allow(unused_import)]
 /// use foo::bar;
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub USELESS_ATTRIBUTE,
-    Warn,
+    correctness,
     "use of lint attributes on `extern crate` items"
 }
 
@@ -72,9 +75,9 @@
 /// #[deprecated(since = "forever")]
 /// fn something_else(..) { ... }
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub DEPRECATED_SEMVER,
-    Warn,
+    correctness,
     "use of `#[deprecated(since = \"x\")]` where x is not semver"
 }
 
 /// If it was meant to be an outer attribute, then the following item
 /// should not be separated by empty lines.
 ///
-/// **Known problems:** None
+/// **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
 /// #[inline(always)]
 /// fn this_is_fine_too(..) { ... }
 /// ```
-declare_lint! {
+declare_clippy_lint! {
     pub EMPTY_LINE_AFTER_OUTER_ATTR,
-    Warn,
+    nursery,
     "empty line after outer attribute"
 }
 
 
 impl LintPass for AttrPass {
     fn get_lints(&self) -> LintArray {
-        lint_array!(INLINE_ALWAYS, DEPRECATED_SEMVER, USELESS_ATTRIBUTE, EMPTY_LINE_AFTER_OUTER_ATTR)
+        lint_array!(
+            INLINE_ALWAYS,
+            DEPRECATED_SEMVER,
+            USELESS_ATTRIBUTE,
+            EMPTY_LINE_AFTER_OUTER_ATTR
+        )
     }
 }
 
 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") {
+            if items.is_empty() || attr.name() != "deprecated" {
                 return;
             }
             for item in items {
@@ -139,46 +151,40 @@ fn check_attribute(&mut self, cx: &LateContext<'a, 'tcx>, attr: &'tcx Attribute)
 
     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)
+            check_attrs(cx, item.span, item.name, &item.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 &*attr.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;
                                         }
                                     }
-                                    let line_span = last_line_of_span(cx, attr.span);
+                                }
+                                let line_span = last_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",
-                                                |db| {
-                                                    sugg = sugg.replacen("#[", "#![", 1);
-                                                    db.span_suggestion(
-                                                        line_span,
-                                                        "if you just forgot a `!`, use",
-                                                        sugg,
-                                                    );
-                                                },
-                                            );
-                                        }
+                                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",
+                                            |db| {
+                                                sugg = sugg.replacen("#[", "#![", 1);
+                                                db.span_suggestion(line_span, "if you just forgot a `!`, use", sugg);
+                                            },
+                                        );
                                     }
-                                },
-                                _ => {},
-                            }
+                                }
+                            },
+                            _ => {},
                         }
                     }
                 }
@@ -189,19 +195,19 @@ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
 
     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)
+            check_attrs(cx, item.span, item.ident.name, &item.attrs)
         }
     }
 
     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)
+            check_attrs(cx, item.span, item.ident.name, &item.attrs)
         }
     }
 }
 
 fn is_relevant_item(tcx: TyCtxt, item: &Item) -> bool {
-    if let ItemFn(_, _, _, _, _, eid) = item.node {
+    if let ItemFn(_, _, _, eid) = item.node {
         is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir.body(eid).value)
     } else {
         true
@@ -232,16 +238,13 @@ fn is_relevant_block(tcx: TyCtxt, tables: &ty::TypeckTables, block: &Block) -> b
             StmtExpr(ref expr, _) | StmtSemi(ref expr, _) => is_relevant_expr(tcx, tables, expr),
         }
     } else {
-        block
-            .expr
-            .as_ref()
-            .map_or(false, |e| is_relevant_expr(tcx, tables, e))
+        block.expr.as_ref().map_or(false, |e| is_relevant_expr(tcx, tables, e))
     }
 }
 
 fn is_relevant_expr(tcx: TyCtxt, tables: &ty::TypeckTables, expr: &Expr) -> bool {
     match expr.node {
-        ExprBlock(ref block) => is_relevant_block(tcx, tables, block),
+        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 {
@@ -257,7 +260,7 @@ fn is_relevant_expr(tcx: TyCtxt, tables: &ty::TypeckTables, expr: &Expr) -> bool
     }
 }
 
-fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
+fn check_attrs(cx: &LateContext, span: Span, name: Name, attrs: &[Attribute]) {
     if in_macro(span) {
         return;
     }
@@ -267,7 +270,7 @@ fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
             return;
         }
         if attr.style == AttrStyle::Outer {
-            if !is_present_in_source(cx, attr.span) {
+            if attr.tokens.is_empty() || !is_present_in_source(cx, attr.span) {
                 return;
             }
 
@@ -276,6 +279,8 @@ fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
 
             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,
@@ -288,7 +293,7 @@ fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
         }
 
         if let Some(ref values) = attr.meta_item_list() {
-            if values.len() != 1 || attr.name().map_or(true, |n| n != "inline") {
+            if values.len() != 1 || attr.name() != "inline" {
                 continue;
             }
             if is_word(&values[0], "always") {