rustdoc: pass around decoration info by ref

src/librustdoc/html/highlight.rs

@@ -233,7 +233,7 @@ pub(super) fn write_code(
     out: &mut impl Write,
     src: &str,
     href_context: Option<HrefContext<'_, '_>>,
-    decoration_info: Option<DecorationInfo>,
+    decoration_info: Option<&DecorationInfo>,
 ) {
     // This replace allows to fix how the code source with DOS backline characters is displayed.
     let src = src.replace("\r\n", "\n");
@@ -510,12 +510,12 @@ struct Decorations {
 }
 
 impl Decorations {
-    fn new(info: DecorationInfo) -> Self {
+    fn new(info: &DecorationInfo) -> Self {
         // Extract tuples (start, end, kind) into separate sequences of (start, kind) and (end).
         let (mut starts, mut ends): (Vec<_>, Vec<_>) = info
             .0
-            .into_iter()
-            .flat_map(|(kind, ranges)| ranges.into_iter().map(move |(lo, hi)| ((lo, kind), hi)))
+            .iter()
+            .flat_map(|(&kind, ranges)| ranges.into_iter().map(move |&(lo, hi)| ((lo, kind), hi)))
             .unzip();
 
         // Sort the sequences in document order.
@@ -542,7 +542,7 @@ struct Classifier<'src> {
 impl<'src> Classifier<'src> {
     /// Takes as argument the source code to HTML-ify, the rust edition to use and the source code
     /// file span which will be used later on by the `span_correspondence_map`.
-    fn new(src: &str, file_span: Span, decoration_info: Option<DecorationInfo>) -> Classifier<'_> {
+    fn new(src: &'src str, file_span: Span, decoration_info: Option<&DecorationInfo>) -> Self {
         let tokens = PeekIter::new(TokenIter { src, cursor: Cursor::new(src) });
         let decorations = decoration_info.map(Decorations::new);
         Classifier {

src/librustdoc/html/highlight/tests.rs

@@ -78,7 +78,7 @@ let a = 4;";
         decorations.insert("example2", vec![(22, 32)]);
 
         let mut html = Buffer::new();
-        write_code(&mut html, src, None, Some(DecorationInfo(decorations)));
+        write_code(&mut html, src, None, Some(&DecorationInfo(decorations)));
         expect_file!["fixtures/decorations.html"].assert_eq(&html.into_inner());
     });
 }

src/librustdoc/html/render/mod.rs

@@ -2577,7 +2577,7 @@ fn render_call_locations<W: fmt::Write>(mut w: W, cx: &Context<'_>, item: &clean
             file_span,
             cx,
             &cx.root_path(),
-            highlight::DecorationInfo(decoration_info),
+            &highlight::DecorationInfo(decoration_info),
             sources::SourceContext::Embedded(sources::ScrapedInfo {
                 needs_expansion,
                 offset: line_min,

src/librustdoc/html/sources.rs

@@ -249,7 +249,7 @@ impl SourceCollector<'_, '_> {
                     file_span,
                     self.cx,
                     &root_path,
-                    highlight::DecorationInfo::default(),
+                    &highlight::DecorationInfo::default(),
                     SourceContext::Standalone { file_path },
                 )
             },
@@ -328,7 +328,7 @@ pub(crate) fn print_src(
     file_span: rustc_span::Span,
     context: &Context<'_>,
     root_path: &str,
-    decoration_info: highlight::DecorationInfo,
+    decoration_info: &highlight::DecorationInfo,
     source_context: SourceContext<'_>,
 ) {
     let current_href = context