From ae644a2d4df673f5063d5b127488b7f03fef15a6 Mon Sep 17 00:00:00 2001
From: Nixon Enraght-Moony <nixon.emoony@gmail.com>
Date: Wed, 18 Nov 2020 13:38:17 +0000
Subject: [PATCH] add [src] links to methods on a trait's page

---
 src/librustdoc/html/render/mod.rs      | 31 ++++++++++----------------
 src/librustdoc/html/static/rustdoc.css | 10 ++++-----
 src/test/rustdoc/trait-src-link.rs     | 26 +++++++++++++++++++++
 3 files changed, 43 insertions(+), 24 deletions(-)
 create mode 100644 src/test/rustdoc/trait-src-link.rs

diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 70969984b07..147a8d33765 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -86,11 +86,7 @@
 
 crate fn ensure_trailing_slash(v: &str) -> impl fmt::Display + '_ {
     crate::html::format::display_fn(move |f| {
-        if !v.ends_with('/') && !v.is_empty() {
-            write!(f, "{}/", v)
-        } else {
-            write!(f, "{}", v)
-        }
+        if !v.ends_with('/') && !v.is_empty() { write!(f, "{}/", v) } else { write!(f, "{}", v) }
     })
 }
 
@@ -1950,11 +1946,7 @@ fn document_stability(
 }
 
 fn document_non_exhaustive_header(item: &clean::Item) -> &str {
-    if item.is_non_exhaustive() {
-        " (Non-exhaustive)"
-    } else {
-        ""
-    }
+    if item.is_non_exhaustive() { " (Non-exhaustive)" } else { "" }
 }
 
 fn document_non_exhaustive(w: &mut Buffer, item: &clean::Item) {
@@ -2636,7 +2628,7 @@ fn write_loading_content(w: &mut Buffer, extra_content: &str) {
         write!(w, "{}<span class=\"loading-content\">Loading content...</span>", extra_content)
     }
 
-    fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item) {
+    fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item, cache: &Cache) {
         let name = m.name.as_ref().unwrap();
         info!("Documenting {} on {}", name, t.name.as_deref().unwrap_or_default());
         let item_type = m.type_();
@@ -2645,6 +2637,7 @@ fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item) {
         render_assoc_item(w, m, AssocItemLink::Anchor(Some(&id)), ItemType::Impl);
         write!(w, "</code>");
         render_stability_since(w, m, t);
+        write_srclink(cx, m, w, cache);
         write!(w, "</h3>");
         document(w, cx, m, Some(t));
     }
@@ -2656,8 +2649,8 @@ fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item) {
             "Associated Types",
             "<div class=\"methods\">",
         );
-        for t in &types {
-            trait_item(w, cx, *t, it);
+        for t in types {
+            trait_item(w, cx, t, it, cache);
         }
         write_loading_content(w, "</div>");
     }
@@ -2669,8 +2662,8 @@ fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item) {
             "Associated Constants",
             "<div class=\"methods\">",
         );
-        for t in &consts {
-            trait_item(w, cx, *t, it);
+        for t in consts {
+            trait_item(w, cx, t, it, cache);
         }
         write_loading_content(w, "</div>");
     }
@@ -2683,8 +2676,8 @@ fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item) {
             "Required methods",
             "<div class=\"methods\">",
         );
-        for m in &required {
-            trait_item(w, cx, *m, it);
+        for m in required {
+            trait_item(w, cx, m, it, cache);
         }
         write_loading_content(w, "</div>");
     }
@@ -2695,8 +2688,8 @@ fn trait_item(w: &mut Buffer, cx: &Context, m: &clean::Item, t: &clean::Item) {
             "Provided methods",
             "<div class=\"methods\">",
         );
-        for m in &provided {
-            trait_item(w, cx, *m, it);
+        for m in provided {
+            trait_item(w, cx, m, it, cache);
         }
         write_loading_content(w, "</div>");
     }
diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index 7eccb09b073..7d22913b99d 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -659,7 +659,7 @@ a {
 	text-decoration: underline;
 }
 
-.invisible > .srclink, h4 > code + .srclink {
+.invisible > .srclink, h4 > code + .srclink, h3 > code + .srclink {
 	position: absolute;
 	top: 0;
 	right: 0;
@@ -857,25 +857,25 @@ body.blur > :not(#help) {
 	top: 0;
 }
 
-.impl-items .since, .impl .since {
+.impl-items .since, .impl .since, .methods .since {
 	flex-grow: 0;
 	padding-left: 12px;
 	padding-right: 2px;
 	position: initial;
 }
 
-.impl-items .srclink, .impl .srclink {
+.impl-items .srclink, .impl .srclink, .methods .srclink {
 	flex-grow: 0;
 	/* Override header settings otherwise it's too bold */
 	font-size: 17px;
 	font-weight: normal;
 }
 
-.impl-items code, .impl code {
+.impl-items code, .impl code, .methods code {
 	flex-grow: 1;
 }
 
-.impl-items h4, h4.impl, h3.impl {
+.impl-items h4, h4.impl, h3.impl, .methods h3 {
 	display: flex;
 	flex-basis: 100%;
 	font-size: 16px;
diff --git a/src/test/rustdoc/trait-src-link.rs b/src/test/rustdoc/trait-src-link.rs
new file mode 100644
index 00000000000..77116695690
--- /dev/null
+++ b/src/test/rustdoc/trait-src-link.rs
@@ -0,0 +1,26 @@
+#![crate_name = "quix"]
+pub trait Foo {
+    // @has quix/trait.Foo.html '//a[@href="../src/quix/trait-src-link.rs.html#4"]' '[src]'
+    fn required();
+
+    // @has quix/trait.Foo.html '//a[@href="../src/quix/trait-src-link.rs.html#7"]' '[src]'
+    fn provided() {}
+}
+
+pub struct Bar;
+
+impl Foo for Bar {
+    // @has quix/struct.Bar.html '//a[@href="../src/quix/trait-src-link.rs.html#14"]' '[src]'
+    fn required() {}
+    // @has quix/struct.Bar.html '//a[@href="../src/quix/trait-src-link.rs.html#7"]' '[src]'
+}
+
+pub struct Baz;
+
+impl Foo for Baz {
+    // @has quix/struct.Baz.html '//a[@href="../src/quix/trait-src-link.rs.html#22"]' '[src]'
+    fn required() {}
+
+    // @has quix/struct.Baz.html '//a[@href="../src/quix/trait-src-link.rs.html#25"]' '[src]'
+    fn provided() {}
+}