Update to latest rustc and rustdoc styles

Author: willcrichton

src/doc/rustdoc/src/unstable-features.md

@@ -455,3 +455,17 @@ Calculating code examples follows these rules:
   * static
   * typedef
 2. If one of the previously listed items has a code example, then it'll be counted.
+
+### `--with-examples`: include examples of uses of items as documentation
+
+This option, combined with `--scrape-examples-target-crate` and `--scrape-examples-output-path`, is used to implement the functionality in [RFC #3123](https://github.com/rust-lang/rfcs/pull/3123). Uses of an item (currently functions / call-sites) are found in a crate and its reverse-dependencies, and then the uses are included as documentation for that item. This feature is intended to be used via `cargo doc --scrape-examples`, but the rustdoc-only workflow looks like:
+
+```bash
+$ rustdoc examples/ex.rs -Z unstable-options \
+    --extern foobar=target/deps/libfoobar.rmeta
+    --scrape-examples-target-crate foobar \
+    --scrape-examples-output-path output.calls
+$ rustdoc src/lib.rs -Z unstable-options --with-examples output.calls
+```
+
+First, the library must be checked to generate an `rmeta`. Then a reverse-dependency like `examples/ex.rs` is given to rustdoc with the target crate being documented (`foobar`) and a path to output the calls (`output.calls`). Then, the generated calls file can be passed via `--with-examples` to the subsequent documentation of `foobar`.

src/librustdoc/html/render/mod.rs

@@ -72,8 +72,8 @@ use crate::html::format::{
     href, print_abi_with_space, print_constness_with_space, print_default_space,
     print_generic_bounds, print_where_clause, Buffer, HrefError, PrintWithSpace,
 };
-use crate::html::markdown::{HeadingOffset, Markdown, MarkdownHtml, MarkdownSummaryLine};
 use crate::html::highlight;
+use crate::html::markdown::{HeadingOffset, Markdown, MarkdownHtml, MarkdownSummaryLine};
 use crate::html::sources;
 use crate::scrape_examples::CallData;
 
@@ -2479,9 +2479,10 @@ fn render_call_locations(w: &mut Buffer, cx: &Context<'_>, def_id: DefId, item:
     write!(
         w,
         "<div class=\"docblock scraped-example-list\">\
-          <h1 id=\"scraped-examples\" class=\"small-section-header\">\
+          <span></span>
+          <h5 id=\"scraped-examples\" class=\"section-header\">\
              <a href=\"#{}\">Examples found in repository</a>\
-          </h1>",
+          </h5>",
         id
     );
 

src/librustdoc/html/static/css/rustdoc.css

@@ -2071,6 +2071,10 @@ details.undocumented[open] > summary::before {
 	background: #f6fdb0;
 }
 
+.more-examples-toggle {
+	margin-top: 10px;
+}
+
 .more-examples-toggle summary {
 	color: #999;
 	font-family: 'Fira Sans';
@@ -2106,10 +2110,6 @@ details.undocumented[open] > summary::before {
 	height: 100%;
 }
 
-h1 + .scraped-example {
-	margin-bottom: 10px;
-}
-
 .more-scraped-examples .scraped-example {
 	margin-bottom: 20px;
 }

src/librustdoc/scrape_examples.rs

@@ -216,7 +216,7 @@ crate fn run(
         // Run call-finder on all items
         let mut calls = FxHashMap::default();
         let mut finder = FindCalls { calls: &mut calls, tcx, map: tcx.hir(), cx, target_crates };
-        tcx.hir().krate().visit_all_item_likes(&mut finder.as_deep_visitor());
+        tcx.hir().visit_all_item_likes(&mut finder.as_deep_visitor());
 
         // Save output to provided path
         let mut encoder = FileEncoder::new(options.output_path).map_err(|e| e.to_string())?;