Auto merge of #4938 - flip1995:rustup, r=flip1995

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

diff --git a/clippy_lints/src/dbg_macro.rs b/clippy_lints/src/dbg_macro.rs
index 93d2007d3a55f1c41f46744ca7db1fce98a13bb1..48fc601e726cf6ef35c86b8192c3708731b8f2cc 100644 (file)
--- a/clippy_lints/src/dbg_macro.rs
+++ b/clippy_lints/src/dbg_macro.rs
@@ -1,53 +1,65 @@
-use crate::utils::span_help_and_lint;
+use crate::utils::{snippet_opt, span_help_and_lint, span_lint_and_sugg};
+use rustc::declare_lint_pass;
 use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
 use rustc_errors::Applicability;
+use rustc_session::declare_tool_lint;
 use syntax::ast;
+use syntax::source_map::Span;
+use syntax::tokenstream::TokenStream;
 
-/// **What it does:** Checks for usage of dbg!() macro.
-///
-/// **Why is this bad?** `dbg!` macro is intended as a debugging tool. It
-/// should not be in version control.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust,ignore
-/// // Bad
-/// dbg!(true)
-///
-/// // Good
-/// true
-/// ```
 declare_clippy_lint! {
+    /// **What it does:** Checks for usage of dbg!() macro.
+    ///
+    /// **Why is this bad?** `dbg!` macro is intended as a debugging tool. It
+    /// should not be in version control.
+    ///
+    /// **Known problems:** None.
+    ///
+    /// **Example:**
+    /// ```rust,ignore
+    /// // Bad
+    /// dbg!(true)
+    ///
+    /// // Good
+    /// true
+    /// ```
     pub DBG_MACRO,
     restriction,
     "`dbg!` macro is intended as a debugging tool"
 }
 
-#[derive(Copy, Clone, Debug)]
-pub struct Pass;
+declare_lint_pass!(DbgMacro => [DBG_MACRO]);
 
-impl LintPass for Pass {
-    fn get_lints(&self) -> LintArray {
-        lint_array!(DBG_MACRO)
-    }
-
-    fn name(&self) -> &'static str {
-        "DbgMacro"
-    }
-}
-
-impl EarlyLintPass for Pass {
+impl EarlyLintPass for DbgMacro {
     fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::Mac) {
-        if mac.node.path == "dbg" {
-            span_help_and_lint(
-                cx,
-                DBG_MACRO,
-                mac.span,
-                "`dbg!` macro is intended as a debugging tool",
-                "ensure to avoid having uses of it in version control",
-            );
+        if mac.path == sym!(dbg) {
+            if let Some(sugg) = tts_span(mac.args.inner_tokens()).and_then(|span| snippet_opt(cx, span)) {
+                span_lint_and_sugg(
+                    cx,
+                    DBG_MACRO,
+                    mac.span(),
+                    "`dbg!` macro is intended as a debugging tool",
+                    "ensure to avoid having uses of it in version control",
+                    sugg,
+                    Applicability::MaybeIncorrect,
+                );
+            } else {
+                span_help_and_lint(
+                    cx,
+                    DBG_MACRO,
+                    mac.span(),
+                    "`dbg!` macro is intended as a debugging tool",
+                    "ensure to avoid having uses of it in version control",
+                );
+            }
         }
     }
 }
+
+// Get span enclosing entire the token stream.
+fn tts_span(tts: TokenStream) -> Option<Span> {
+    let mut cursor = tts.into_trees();
+    let first = cursor.next()?.span();
+    let span = cursor.last().map_or(first, |tree| first.to(tree.span()));
+    Some(span)
+}