From 106625bc5c43da24673c84c2e85e082e3f591a15 Mon Sep 17 00:00:00 2001
From: topecongiro <seuchida@gmail.com>
Date: Thu, 5 Oct 2017 16:17:59 +0900
Subject: [PATCH] Remove trailing whitespaces in macro def

---
 src/comment.rs | 29 +++++++++++++++++++++++++++++
 src/visitor.rs |  6 +++---
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/src/comment.rs b/src/comment.rs
index a236c2699a6..3c863086a36 100644
--- a/src/comment.rs
+++ b/src/comment.rs
@@ -505,6 +505,35 @@ pub fn contains_comment(text: &str) -> bool {
     CharClasses::new(text.chars()).any(|(kind, _)| kind.is_comment())
 }
 
+/// Remove trailing spaces from the specified snippet. We do not remove spaces
+/// inside strings or comments.
+pub fn remove_trailing_white_spaces(text: &str) -> String {
+    let mut buffer = String::with_capacity(text.len());
+    let mut space_buffer = String::with_capacity(128);
+    for (char_kind, c) in CharClasses::new(text.chars()) {
+        match c {
+            '\n' => {
+                if char_kind == FullCodeCharKind::InString {
+                    buffer.push_str(&space_buffer);
+                }
+                space_buffer.clear();
+                buffer.push('\n');
+            }
+            _ if c.is_whitespace() => {
+                space_buffer.push(c);
+            }
+            _ => {
+                if !space_buffer.is_empty() {
+                    buffer.push_str(&space_buffer);
+                    space_buffer.clear();
+                }
+                buffer.push(c);
+            }
+        }
+    }
+    buffer
+}
+
 struct CharClasses<T>
 where
     T: Iterator,
diff --git a/src/visitor.rs b/src/visitor.rs
index f6f46ca6188..29eaea39a7f 100644
--- a/src/visitor.rs
+++ b/src/visitor.rs
@@ -18,8 +18,8 @@
 
 use spanned::Spanned;
 use codemap::{LineRangeUtils, SpanUtils};
-use comment::{contains_comment, recover_missing_comment_in_span, CodeCharKind, CommentCodeSlices,
-              FindUncommented};
+use comment::{contains_comment, recover_missing_comment_in_span, remove_trailing_white_spaces,
+              CodeCharKind, CommentCodeSlices, FindUncommented};
 use comment::rewrite_comment;
 use config::{BraceStyle, Config};
 use items::{format_impl, format_struct, format_struct_struct, format_trait,
@@ -470,7 +470,7 @@ pub fn visit_item(&mut self, item: &ast::Item) {
             }
             ast::ItemKind::MacroDef(..) => {
                 // FIXME(#1539): macros 2.0
-                let mac_snippet = Some(self.snippet(item.span));
+                let mac_snippet = Some(remove_trailing_white_spaces(&self.snippet(item.span)));
                 self.push_rewrite(item.span, mac_snippet);
             }
         }
-- 
2.44.0