1 files changed, 151 insertions, 0 deletions
diff --git a/src/librustdoc/markdown.rs b/src/librustdoc/markdown.rs
new file mode 100644
index 000000000..0b557ef24
--- /dev/null
+++ b/src/librustdoc/markdown.rs
@@ -0,0 +1,151 @@
+use std::fmt::Write as _;
+use std::fs::{create_dir_all, read_to_string, File};
+use std::io::prelude::*;
+use std::path::Path;
+
+use rustc_span::edition::Edition;
+use rustc_span::source_map::DUMMY_SP;
+use rustc_span::Symbol;
+
+use crate::config::{Options, RenderOptions};
+use crate::doctest::{Collector, GlobalTestOptions};
+use crate::html::escape::Escape;
+use crate::html::markdown;
+use crate::html::markdown::{
+    find_testable_code, ErrorCodes, HeadingOffset, IdMap, Markdown, MarkdownWithToc,
+};
+
+/// Separate any lines at the start of the file that begin with `# ` or `%`.
+fn extract_leading_metadata(s: &str) -> (Vec<&str>, &str) {
+    let mut metadata = Vec::new();
+    let mut count = 0;
+
+    for line in s.lines() {
+        if line.starts_with("# ") || line.starts_with('%') {
+            // trim the whitespace after the symbol
+            metadata.push(line[1..].trim_start());
+            count += line.len() + 1;
+        } else {
+            return (metadata, &s[count..]);
+        }
+    }
+
+    // if we're here, then all lines were metadata `# ` or `%` lines.
+    (metadata, "")
+}
+
+/// Render `input` (e.g., "foo.md") into an HTML file in `output`
+/// (e.g., output = "bar" => "bar/foo.html").
+pub(crate) fn render<P: AsRef<Path>>(
+    input: P,
+    options: RenderOptions,
+    edition: Edition,
+) -> Result<(), String> {
+    if let Err(e) = create_dir_all(&options.output) {
+        return Err(format!("{}: {}", options.output.display(), e));
+    }
+
+    let input = input.as_ref();
+    let mut output = options.output;
+    output.push(input.file_name().unwrap());
+    output.set_extension("html");
+
+    let mut css = String::new();
+    for name in &options.markdown_css {
+        write!(css, r#"<link rel="stylesheet" type="text/css" href="{name}">"#)
+            .expect("Writing to a String can't fail");
+    }
+
+    let input_str = read_to_string(input).map_err(|err| format!("{}: {}", input.display(), err))?;
+    let playground_url = options.markdown_playground_url.or(options.playground_url);
+    let playground = playground_url.map(|url| markdown::Playground { crate_name: None, url });
+
+    let mut out = File::create(&output).map_err(|e| format!("{}: {}", output.display(), e))?;
+
+    let (metadata, text) = extract_leading_metadata(&input_str);
+    if metadata.is_empty() {
+        return Err("invalid markdown file: no initial lines starting with `# ` or `%`".to_owned());
+    }
+    let title = metadata[0];
+
+    let mut ids = IdMap::new();
+    let error_codes = ErrorCodes::from(options.unstable_features.is_nightly_build());
+    let text = if !options.markdown_no_toc {
+        MarkdownWithToc(text, &mut ids, error_codes, edition, &playground).into_string()
+    } else {
+        Markdown {
+            content: text,
+            links: &[],
+            ids: &mut ids,
+            error_codes,
+            edition,
+            playground: &playground,
+            heading_offset: HeadingOffset::H1,
+        }
+        .into_string()
+    };
+
+    let err = write!(
+        &mut out,
+        r#"<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta name="generator" content="rustdoc">
+    <title>{title}</title>
+
+    {css}
+    {in_header}
+</head>
+<body class="rustdoc">
+    <!--[if lte IE 8]>
+    <div class="warning">
+        This old browser is unsupported and will most likely display funky
+        things.
+    </div>
+    <![endif]-->
+
+    {before_content}
+    <h1 class="title">{title}</h1>
+    {text}
+    {after_content}
+</body>
+</html>"#,
+        title = Escape(title),
+        css = css,
+        in_header = options.external_html.in_header,
+        before_content = options.external_html.before_content,
+        text = text,
+        after_content = options.external_html.after_content,
+    );
+
+    match err {
+        Err(e) => Err(format!("cannot write to `{}`: {}", output.display(), e)),
+        Ok(_) => Ok(()),
+    }
+}
+
+/// Runs any tests/code examples in the markdown file `input`.
+pub(crate) fn test(options: Options) -> Result<(), String> {
+    let input_str = read_to_string(&options.input)
+        .map_err(|err| format!("{}: {}", options.input.display(), err))?;
+    let mut opts = GlobalTestOptions::default();
+    opts.no_crate_inject = true;
+    let mut collector = Collector::new(
+        Symbol::intern(&options.input.display().to_string()),
+        options.clone(),
+        true,
+        opts,
+        None,
+        Some(options.input),
+        options.enable_per_target_ignores,
+    );
+    collector.set_position(DUMMY_SP);
+    let codes = ErrorCodes::from(options.render_options.unstable_features.is_nightly_build());
+
+    find_testable_code(&input_str, &mut collector, codes, options.enable_per_target_ignores, None);
+
+    crate::doctest::run_tests(options.test_args, options.nocapture, collector.tests);
+    Ok(())
+}