Rollup merge of rust-lang#99337 - jsha:simplify-highlight, r=GuillaumeGomez

rustdoc: simplify highlight.rs

Split render_with_highlighting, which took many optional parameters, into three functions for specific purposes, which each take a smaller number of mostly required parameters.

Remove some plumbing to pass through an "edition" parameter, which was used solely to avoid highlighting some 2021 Edition keywords in non-2021 code.

I've tested a build of std docs before and after, and this does not change the generated HTML at all.

Followup from rust-lang#91264 (comment)

r? ```@GuillaumeGomez```

Author: matthiaskrgr

src/librustdoc/html/highlight.rs

@@ -33,48 +33,80 @@ pub(crate) struct HrefContext<'a, 'b, 'c> {
 
 /// Decorations are represented as a map from CSS class to vector of character ranges.
 /// Each range will be wrapped in a span with that class.
+#[derive(Default)]
 pub(crate) struct DecorationInfo(pub(crate) FxHashMap<&'static str, Vec<(u32, u32)>>);
 
-/// Highlights `src`, returning the HTML output.
-pub(crate) fn render_with_highlighting(
+#[derive(Eq, PartialEq, Clone, Copy)]
+pub(crate) enum Tooltip {
+    Ignore,
+    CompileFail,
+    ShouldPanic,
+    Edition(Edition),
+    None,
+}
+
+/// Highlights `src` as an inline example, returning the HTML output.
+pub(crate) fn render_example_with_highlighting(
     src: &str,
     out: &mut Buffer,
-    class: Option<&str>,
+    tooltip: Tooltip,
     playground_button: Option<&str>,
-    tooltip: Option<(Option<Edition>, &str)>,
-    edition: Edition,
-    extra_content: Option<Buffer>,
-    href_context: Option<HrefContext<'_, '_, '_>>,
-    decoration_info: Option<DecorationInfo>,
 ) {
-    debug!("highlighting: ================\n{}\n==============", src);
-    if let Some((edition_info, class)) = tooltip {
+    let class = match tooltip {
+        Tooltip::Ignore => " ignore",
+        Tooltip::CompileFail => " compile_fail",
+        Tooltip::ShouldPanic => " should_panic",
+        Tooltip::Edition(_) => " edition",
+        Tooltip::None => "",
+    };
+
+    if tooltip != Tooltip::None {
         write!(
             out,
-            "<div class='information'><div class='tooltip {}'{}>ⓘ</div></div>",
+            "<div class='information'><div class='tooltip{}'{}>ⓘ</div></div>",
             class,
-            if let Some(edition_info) = edition_info {
+            if let Tooltip::Edition(edition_info) = tooltip {
                 format!(" data-edition=\"{}\"", edition_info)
             } else {
                 String::new()
             },
         );
     }
 
-    write_header(out, class, extra_content);
-    write_code(out, src, edition, href_context, decoration_info);
+    write_header(out, &format!("rust-example-rendered{}", class), None);
+    write_code(out, src, None, None);
     write_footer(out, playground_button);
 }
 
-fn write_header(out: &mut Buffer, class: Option<&str>, extra_content: Option<Buffer>) {
+/// Highlights `src` as a macro, returning the HTML output.
+pub(crate) fn render_macro_with_highlighting(src: &str, out: &mut Buffer) {
+    write_header(out, "macro", None);
+    write_code(out, src, None, None);
+    write_footer(out, None);
+}
+
+/// Highlights `src` as a source code page, returning the HTML output.
+pub(crate) fn render_source_with_highlighting(
+    src: &str,
+    out: &mut Buffer,
+    line_numbers: Buffer,
+    href_context: HrefContext<'_, '_, '_>,
+    decoration_info: DecorationInfo,
+) {
+    write_header(out, "", Some(line_numbers));
+    write_code(out, src, Some(href_context), Some(decoration_info));
+    write_footer(out, None);
+}
+
+fn write_header(out: &mut Buffer, class: &str, extra_content: Option<Buffer>) {
     write!(out, "<div class=\"example-wrap\">");
     if let Some(extra) = extra_content {
         out.push_buffer(extra);
     }
-    if let Some(class) = class {
-        write!(out, "<pre class=\"rust {}\">", class);
-    } else {
+    if class.is_empty() {
         write!(out, "<pre class=\"rust\">");
+    } else {
+        write!(out, "<pre class=\"rust {}\">", class);
     }
     write!(out, "<code>");
 }
@@ -93,7 +125,6 @@ fn write_header(out: &mut Buffer, class: Option<&str>, extra_content: Option<Buf
 fn write_code(
     out: &mut Buffer,
     src: &str,
-    edition: Edition,
     href_context: Option<HrefContext<'_, '_, '_>>,
     decoration_info: Option<DecorationInfo>,
 ) {
@@ -102,7 +133,6 @@ fn write_code(
     let mut closing_tags: Vec<&'static str> = Vec::new();
     Classifier::new(
         &src,
-        edition,
         href_context.as_ref().map(|c| c.file_span).unwrap_or(DUMMY_SP),
         decoration_info,
     )
@@ -220,7 +250,7 @@ impl<'a> Iterator for TokenIter<'a> {
 }
 
 /// Classifies into identifier class; returns `None` if this is a non-keyword identifier.
-fn get_real_ident_class(text: &str, edition: Edition, allow_path_keywords: bool) -> Option<Class> {
+fn get_real_ident_class(text: &str, allow_path_keywords: bool) -> Option<Class> {
     let ignore: &[&str] =
         if allow_path_keywords { &["self", "Self", "super", "crate"] } else { &["self", "Self"] };
     if ignore.iter().any(|k| *k == text) {
@@ -229,7 +259,7 @@ fn get_real_ident_class(text: &str, edition: Edition, allow_path_keywords: bool)
     Some(match text {
         "ref" | "mut" => Class::RefKeyWord,
         "false" | "true" => Class::Bool,
-        _ if Symbol::intern(text).is_reserved(|| edition) => Class::KeyWord,
+        _ if Symbol::intern(text).is_reserved(|| Edition::Edition2021) => Class::KeyWord,
         _ => return None,
     })
 }
@@ -311,7 +341,6 @@ struct Classifier<'a> {
     in_attribute: bool,
     in_macro: bool,
     in_macro_nonterminal: bool,
-    edition: Edition,
     byte_pos: u32,
     file_span: Span,
     src: &'a str,
@@ -321,20 +350,14 @@ struct Classifier<'a> {
 impl<'a> Classifier<'a> {
     /// 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_correspondance_map`.
-    fn new(
-        src: &str,
-        edition: Edition,
-        file_span: Span,
-        decoration_info: Option<DecorationInfo>,
-    ) -> Classifier<'_> {
+    fn new(src: &str, file_span: Span, decoration_info: Option<DecorationInfo>) -> Classifier<'_> {
         let tokens = PeekIter::new(TokenIter { src });
         let decorations = decoration_info.map(Decorations::new);
         Classifier {
             tokens,
             in_attribute: false,
             in_macro: false,
             in_macro_nonterminal: false,
-            edition,
             byte_pos: 0,
             file_span,
             src,
@@ -354,7 +377,6 @@ impl<'a> Classifier<'a> {
         let start = self.byte_pos as usize;
         let mut pos = start;
         let mut has_ident = false;
-        let edition = self.edition;
 
         loop {
             let mut nb = 0;
@@ -376,7 +398,7 @@ impl<'a> Classifier<'a> {
 
             if let Some((None, text)) = self.tokens.peek().map(|(token, text)| {
                 if *token == TokenKind::Ident {
-                    let class = get_real_ident_class(text, edition, true);
+                    let class = get_real_ident_class(text, true);
                     (class, text)
                 } else {
                     // Doesn't matter which Class we put in here...
@@ -634,7 +656,7 @@ impl<'a> Classifier<'a> {
                 sink(Highlight::Token { text, class: None });
                 return;
             }
-            TokenKind::Ident => match get_real_ident_class(text, self.edition, false) {
+            TokenKind::Ident => match get_real_ident_class(text, false) {
                 None => match text {
                     "Option" | "Result" => Class::PreludeTy,
                     "Some" | "None" | "Ok" | "Err" => Class::PreludeVal,

src/librustdoc/html/highlight/tests.rs

@@ -3,7 +3,6 @@ use crate::html::format::Buffer;
 use expect_test::expect_file;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::create_default_session_globals_then;
-use rustc_span::edition::Edition;
 
 const STYLE: &str = r#"
 <style>
@@ -23,7 +22,7 @@ fn test_html_highlighting() {
         let src = include_str!("fixtures/sample.rs");
         let html = {
             let mut out = Buffer::new();
-            write_code(&mut out, src, Edition::Edition2018, None, None);
+            write_code(&mut out, src, None, None);
             format!("{}<pre><code>{}</code></pre>\n", STYLE, out.into_inner())
         };
         expect_file!["fixtures/sample.html"].assert_eq(&html);
@@ -37,7 +36,7 @@ fn test_dos_backline() {
     println!(\"foo\");\r\n\
 }\r\n";
         let mut html = Buffer::new();
-        write_code(&mut html, src, Edition::Edition2018, None, None);
+        write_code(&mut html, src, None, None);
         expect_file!["fixtures/dos_line.html"].assert_eq(&html.into_inner());
     });
 }
@@ -51,7 +50,7 @@ let x = super::b::foo;
 let y = Self::whatever;";
 
         let mut html = Buffer::new();
-        write_code(&mut html, src, Edition::Edition2018, None, None);
+        write_code(&mut html, src, None, None);
         expect_file!["fixtures/highlight.html"].assert_eq(&html.into_inner());
     });
 }
@@ -61,7 +60,7 @@ fn test_union_highlighting() {
     create_default_session_globals_then(|| {
         let src = include_str!("fixtures/union.rs");
         let mut html = Buffer::new();
-        write_code(&mut html, src, Edition::Edition2018, None, None);
+        write_code(&mut html, src, None, None);
         expect_file!["fixtures/union.html"].assert_eq(&html.into_inner());
     });
 }
@@ -75,7 +74,7 @@ let y = 2;";
         decorations.insert("example", vec![(0, 10)]);
 
         let mut html = Buffer::new();
-        write_code(&mut html, src, Edition::Edition2018, 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/markdown.rs

@@ -330,34 +330,27 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
         });
 
         let tooltip = if ignore != Ignore::None {
-            Some((None, "ignore"))
+            highlight::Tooltip::Ignore
         } else if compile_fail {
-            Some((None, "compile_fail"))
+            highlight::Tooltip::CompileFail
         } else if should_panic {
-            Some((None, "should_panic"))
+            highlight::Tooltip::ShouldPanic
         } else if explicit_edition {
-            Some((Some(edition), "edition"))
+            highlight::Tooltip::Edition(edition)
         } else {
-            None
+            highlight::Tooltip::None
         };
 
         // insert newline to clearly separate it from the
         // previous block so we can shorten the html output
         let mut s = Buffer::new();
         s.push_str("\n");
-        highlight::render_with_highlighting(
+
+        highlight::render_example_with_highlighting(
             &text,
             &mut s,
-            Some(&format!(
-                "rust-example-rendered{}",
-                if let Some((_, class)) = tooltip { format!(" {}", class) } else { String::new() }
-            )),
-            playground_button.as_deref(),
             tooltip,
-            edition,
-            None,
-            None,
-            None,
+            playground_button.as_deref(),
         );
         Some(Event::Html(s.into_inner().into()))
     }

src/librustdoc/html/render/mod.rs

@@ -2773,11 +2773,10 @@ fn render_call_locations(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Ite
         sources::print_src(
             w,
             contents_subset,
-            call_data.edition,
             file_span,
             cx,
             &root_path,
-            Some(highlight::DecorationInfo(decoration_info)),
+            highlight::DecorationInfo(decoration_info),
             sources::SourceContext::Embedded { offset: line_min },
         );
         write!(w, "</div></div>");

src/librustdoc/html/render/print_item.rs

@@ -1322,17 +1322,7 @@ fn item_enum(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, e: &clean::
 
 fn item_macro(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::Macro) {
     wrap_into_docblock(w, |w| {
-        highlight::render_with_highlighting(
-            &t.source,
-            w,
-            Some("macro"),
-            None,
-            None,
-            it.span(cx.tcx()).inner().edition(),
-            None,
-            None,
-            None,
-        );
+        highlight::render_macro_with_highlighting(&t.source, w);
     });
     document(w, cx, it, None, HeadingOffset::H2)
 }

src/librustdoc/html/sources.rs

@@ -11,7 +11,6 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
-use rustc_span::edition::Edition;
 use rustc_span::source_map::FileName;
 
 use std::ffi::OsStr;
@@ -213,11 +212,10 @@ impl SourceCollector<'_, '_> {
                 print_src(
                     buf,
                     contents,
-                    cx.shared.edition(),
                     file_span,
                     cx,
                     &root_path,
-                    None,
+                    highlight::DecorationInfo::default(),
                     SourceContext::Standalone,
                 )
             },
@@ -266,11 +264,10 @@ pub(crate) enum SourceContext {
 pub(crate) fn print_src(
     buf: &mut Buffer,
     s: &str,
-    edition: Edition,
     file_span: rustc_span::Span,
     context: &Context<'_>,
     root_path: &str,
-    decoration_info: Option<highlight::DecorationInfo>,
+    decoration_info: highlight::DecorationInfo,
     source_context: SourceContext,
 ) {
     let lines = s.lines().count();
@@ -289,15 +286,11 @@ pub(crate) fn print_src(
         }
     }
     line_numbers.write_str("</pre>");
-    highlight::render_with_highlighting(
+    highlight::render_source_with_highlighting(
         s,
         buf,
-        None,
-        None,
-        None,
-        edition,
-        Some(line_numbers),
-        Some(highlight::HrefContext { context, file_span, root_path }),
+        line_numbers,
+        highlight::HrefContext { context, file_span, root_path },
         decoration_info,
     );
 }