From b6c503ac32511008ec59cb4a3ad1876a8b94fdb8 Mon Sep 17 00:00:00 2001
From: topecongiro <seuchida@gmail.com>
Date: Sat, 27 May 2017 09:36:25 +0900
Subject: [PATCH] Allow comments after attributes of struct fields

---
 src/items.rs            | 41 ++++++++++++++++++++++++++++++++++-------
 tests/source/structs.rs | 22 ++++++++++++++++++++++
 tests/target/structs.rs | 22 ++++++++++++++++++++++
 3 files changed, 78 insertions(+), 7 deletions(-)

diff --git a/src/items.rs b/src/items.rs
index a23e69d6881..86d2aeb07a5 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -18,7 +18,7 @@
 use lists::{write_list, itemize_list, ListItem, ListFormatting, SeparatorTactic, list_helper,
             DefinitiveListTactic, ListTactic, definitive_tactic, format_item_list};
 use expr::{is_empty_block, is_simple_block_stmt, rewrite_assign_rhs, type_annotation_separator};
-use comment::{FindUncommented, contains_comment};
+use comment::{FindUncommented, contains_comment, rewrite_comment};
 use visitor::FmtVisitor;
 use rewrite::{Rewrite, RewriteContext};
 use config::{Config, IndentStyle, Density, ReturnIndent, BraceStyle, Style, TypeDensity};
@@ -1201,15 +1201,42 @@ fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
         let mut attr_str = try_opt!(self.attrs.rewrite(context,
                                                        Shape::indented(shape.indent,
                                                                        context.config)));
-        if !attr_str.is_empty() {
-            attr_str.push('\n');
-            attr_str.push_str(&shape.indent.to_string(context.config));
-        }
+        // Try format missing comments after attributes
+        let missing_comment = if !self.attrs.is_empty() {
+            let possibly_comment_snippet =
+                context.snippet(mk_sp(self.attrs[self.attrs.len() - 1].span.hi, self.span.lo));
+            let newline_index = possibly_comment_snippet.find('\n');
+            let comment_index = possibly_comment_snippet.find('/');
+            match (newline_index, comment_index) {
+                (Some(i), Some(j)) if i > j => attr_str.push(' '),
+                _ => {
+                    attr_str.push('\n');
+                    attr_str.push_str(&shape.indent.to_string(context.config));
+                }
+            }
+            let trimmed = possibly_comment_snippet.trim();
+            if trimmed.is_empty() {
+                String::new()
+            } else {
+                rewrite_comment(trimmed, false, shape, context.config).map_or(String::new(), |s| {
+                    format!("{}\n{}", s, shape.indent.to_string(context.config))
+                })
+            }
+        } else {
+            String::new()
+        };
 
         let type_annotation_spacing = type_annotation_spacing(context.config);
         let mut result = match name {
-            Some(name) => format!("{}{}{}{}:", attr_str, vis, name, type_annotation_spacing.0),
-            None => format!("{}{}", attr_str, vis),
+            Some(name) => {
+                format!("{}{}{}{}{}:",
+                        attr_str,
+                        missing_comment,
+                        vis,
+                        name,
+                        type_annotation_spacing.0)
+            }
+            None => format!("{}{}{}", attr_str, missing_comment, vis),
         };
 
         let type_offset = shape.indent.block_indent(context.config);
diff --git a/tests/source/structs.rs b/tests/source/structs.rs
index 5dd9087682c..03847ec883f 100644
--- a/tests/source/structs.rs
+++ b/tests/source/structs.rs
@@ -16,6 +16,28 @@ pub struct Foo {
     pub i: TypeForPublicField
 }
 
+// #1029
+pub struct Foo {
+    #[doc(hidden)]
+    // This will NOT get deleted!
+    bar: String, // hi
+}
+
+// #1029
+struct X {
+    // `x` is an important number.
+    #[allow(unused)] // TODO: use
+    x: u32,
+}
+
+// #410
+#[allow(missing_docs)]
+pub struct Writebatch<K: Key> {
+    #[allow(dead_code)] //only used for holding the internal pointer
+    writebatch: RawWritebatch,
+    marker: PhantomData<K>,
+}
+
 struct Bar;
 
 struct NewType(Type,       OtherType);
diff --git a/tests/target/structs.rs b/tests/target/structs.rs
index a89df16376f..2872750c20a 100644
--- a/tests/target/structs.rs
+++ b/tests/target/structs.rs
@@ -16,6 +16,28 @@ pub struct Foo {
     pub i: TypeForPublicField,
 }
 
+// #1029
+pub struct Foo {
+    #[doc(hidden)]
+    // This will NOT get deleted!
+    bar: String, // hi
+}
+
+// #1029
+struct X {
+    // `x` is an important number.
+    #[allow(unused)] // TODO: use
+    x: u32,
+}
+
+// #410
+#[allow(missing_docs)]
+pub struct Writebatch<K: Key> {
+    #[allow(dead_code)] // only used for holding the internal pointer
+    writebatch: RawWritebatch,
+    marker: PhantomData<K>,
+}
+
 struct Bar;
 
 struct NewType(Type, OtherType);