rustup https://github.com/rust-lang/rust/pull/67455

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

diff --git a/clippy_lints/src/if_not_else.rs b/clippy_lints/src/if_not_else.rs
index 62694ae523da0bdf67ad5c2c56119463124c6e7f..7019cfa8cc8f120715eeb8060dbe223456ca5143 100644 (file)
--- a/clippy_lints/src/if_not_else.rs
+++ b/clippy_lints/src/if_not_else.rs
@@ -1,67 +1,78 @@
-//! lint on if branches that could be swapped so no `!` operation is necessary on the condition
+//! lint on if branches that could be swapped so no `!` operation is necessary
+//! on the condition
 
-use rustc::lint::*;
+use rustc::declare_lint_pass;
+use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass};
+use rustc_session::declare_tool_lint;
 use syntax::ast::*;
 
-use utils::span_help_and_lint;
+use crate::utils::span_help_and_lint;
 
-/// **What it does:** Checks for usage of `!` or `!=` in an if condition with an
-/// else branch.
-///
-/// **Why is this bad?** Negations reduce the readability of statements.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// if !v.is_empty() {
-///     a()
-/// } else {
-///     b()
-/// }
-/// ```
-///
-/// Could be written:
-///
-/// ```rust
-/// if v.is_empty() {
-///     b()
-/// } else {
-///     a()
-/// }
-/// ```
-declare_lint! {
-    pub IF_NOT_ELSE, Allow,
-    "finds if branches that could be swapped so no negation operation is necessary on the condition"
+declare_clippy_lint! {
+    /// **What it does:** Checks for usage of `!` or `!=` in an if condition with an
+    /// else branch.
+    ///
+    /// **Why is this bad?** Negations reduce the readability of statements.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// ```rust
+    /// # let v: Vec<usize> = vec![];
+    /// # fn a() {}
+    /// # fn b() {}
+    /// if !v.is_empty() {
+    ///     a()
+    /// } else {
+    ///     b()
+    /// }
+    /// ```
+    ///
+    /// Could be written:
+    ///
+    /// ```rust
+    /// # let v: Vec<usize> = vec![];
+    /// # fn a() {}
+    /// # fn b() {}
+    /// if v.is_empty() {
+    ///     b()
+    /// } else {
+    ///     a()
+    /// }
+    /// ```
+    pub IF_NOT_ELSE,
+    pedantic,
+    "`if` branches that could be swapped so no negation operation is necessary on the condition"
 }
 
-pub struct IfNotElse;
-
-impl LintPass for IfNotElse {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(IF_NOT_ELSE)
-    }
-}
+declare_lint_pass!(IfNotElse => [IF_NOT_ELSE]);
 
 impl EarlyLintPass for IfNotElse {
-    fn check_expr(&mut self, cx: &EarlyContext, item: &Expr) {
-        if let ExprKind::If(ref cond, _, Some(ref els)) = item.node {
-            if let ExprKind::Block(..) = els.node {
-                match cond.node {
+    fn check_expr(&mut self, cx: &EarlyContext<'_>, item: &Expr) {
+        if in_external_macro(cx.sess(), item.span) {
+            return;
+        }
+        if let ExprKind::If(ref cond, _, Some(ref els)) = item.kind {
+            if let ExprKind::Block(..) = els.kind {
+                match cond.kind {
                     ExprKind::Unary(UnOp::Not, _) => {
-                        span_help_and_lint(cx,
-                                           IF_NOT_ELSE,
-                                           item.span,
-                                           "Unnecessary boolean `not` operation",
-                                           "remove the `!` and swap the blocks of the if/else");
-                    }
+                        span_help_and_lint(
+                            cx,
+                            IF_NOT_ELSE,
+                            item.span,
+                            "Unnecessary boolean `not` operation",
+                            "remove the `!` and swap the blocks of the if/else",
+                        );
+                    },
                     ExprKind::Binary(ref kind, _, _) if kind.node == BinOpKind::Ne => {
-                        span_help_and_lint(cx,
-                                           IF_NOT_ELSE,
-                                           item.span,
-                                           "Unnecessary `!=` operation",
-                                           "change to `==` and swap the blocks of the if/else");
-                    }
+                        span_help_and_lint(
+                            cx,
+                            IF_NOT_ELSE,
+                            item.span,
+                            "Unnecessary `!=` operation",
+                            "change to `==` and swap the blocks of the if/else",
+                        );
+                    },
                     _ => (),
                 }
             }