Add new tool to check HTML

Cargo.lock

@@ -1567,6 +1567,13 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "html-checker"
+version = "0.1.0"
+dependencies = [
+ "walkdir",
+]
+
 [[package]]
 name = "html5ever"
 version = "0.25.1"

Cargo.toml

@@ -34,6 +34,7 @@ members = [
   "src/tools/unicode-table-generator",
   "src/tools/expand-yaml-anchors",
   "src/tools/jsondocck",
+  "src/tools/html-checker",
 ]
 
 exclude = [

src/bootstrap/builder.rs

@@ -432,6 +432,7 @@ impl<'a> Builder<'a> {
                 test::RustdocTheme,
                 test::RustdocUi,
                 test::RustdocJson,
+                test::HtmlCheck,
                 // Run bootstrap close to the end as it's unlikely to fail
                 test::Bootstrap,
                 // Run run-make last, since these won't pass without make on Windows

src/bootstrap/doc.rs

@@ -501,8 +501,8 @@ impl Step for Std {
 
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct Rustc {
-    stage: u32,
-    target: TargetSelection,
+    pub stage: u32,
+    pub target: TargetSelection,
 }
 
 impl Step for Rustc {

src/bootstrap/test.rs

@@ -9,7 +9,7 @@ use std::fmt;
 use std::fs;
 use std::iter;
 use std::path::{Path, PathBuf};
-use std::process::Command;
+use std::process::{Command, Stdio};
 
 use build_helper::{self, output, t};
 
@@ -144,6 +144,54 @@ You can skip linkcheck with --exclude src/tools/linkchecker"
     }
 }
 
+fn check_if_tidy_is_installed() -> bool {
+    Command::new("tidy")
+        .arg("--version")
+        .stdout(Stdio::null())
+        .status()
+        .map_or(false, |status| status.success())
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct HtmlCheck {
+    target: TargetSelection,
+}
+
+impl Step for HtmlCheck {
+    type Output = ();
+    const DEFAULT: bool = true;
+    const ONLY_HOSTS: bool = true;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        let run = run.path("src/tools/html-checker");
+        run.default_condition(check_if_tidy_is_installed())
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        run.builder.ensure(HtmlCheck { target: run.target });
+    }
+
+    fn run(self, builder: &Builder<'_>) {
+        if !check_if_tidy_is_installed() {
+            eprintln!("not running HTML-check tool because `tidy` is missing");
+            eprintln!(
+                "Note that `tidy` is not the in-tree `src/tools/tidy` but needs to be installed"
+            );
+            panic!("Cannot run html-check tests");
+        }
+        // Ensure that a few different kinds of documentation are available.
+        builder.default_doc(&[]);
+        builder.ensure(crate::doc::Rustc { target: self.target, stage: builder.top_stage });
+
+        try_run(
+            builder,
+            builder
+                .tool_cmd(Tool::HtmlChecker)
+                .arg(builder.out.join(self.target.triple).join("doc")),
+        );
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Cargotest {
     stage: u32,

src/bootstrap/tool.rs

@@ -375,6 +375,7 @@ bootstrap_tool!(
     ExpandYamlAnchors, "src/tools/expand-yaml-anchors", "expand-yaml-anchors";
     LintDocs, "src/tools/lint-docs", "lint-docs";
     JsonDocCk, "src/tools/jsondocck", "jsondocck";
+    HtmlChecker, "src/tools/html-checker", "html-checker";
 );
 
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, Ord, PartialOrd)]

src/ci/docker/host-x86_64/x86_64-gnu-aux/Dockerfile

@@ -17,7 +17,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   libgl1-mesa-dev \
   llvm-dev \
   libfreetype6-dev \
-  libexpat1-dev
+  libexpat1-dev \
+  tidy
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh

src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile

@@ -12,7 +12,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   cmake \
   libssl-dev \
   sudo \
-  xz-utils
+  xz-utils \
+  tidy
 
 # Install dependencies for chromium browser
 RUN apt-get install -y \

src/tools/html-checker/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "html-checker"
+version = "0.1.0"
+authors = ["Guillaume Gomez <guillaume1.gomez@gmail.com>"]
+edition = "2018"
+
+[[bin]]
+name = "html-checker"
+path = "main.rs"
+
+[dependencies]
+walkdir = "2"

src/tools/html-checker/main.rs

@@ -0,0 +1,93 @@
+use std::env;
+use std::path::Path;
+use std::process::{Command, Output};
+
+fn check_html_file(file: &Path) -> usize {
+    let to_mute = &[
+        // "disabled" on <link> or "autocomplete" on <select> emit this warning
+        "PROPRIETARY_ATTRIBUTE",
+        // It complains when multiple in the same page link to the same anchor for some reason...
+        "ANCHOR_NOT_UNIQUE",
+        // If a <span> contains only HTML elements and no text, it complains about it.
+        "TRIM_EMPTY_ELEMENT",
+        // FIXME: the three next warnings are about <pre> elements which are not supposed to
+        //        contain HTML. The solution here would be to replace them with a <div>
+        "MISSING_ENDTAG_BEFORE",
+        "INSERTING_TAG",
+        "DISCARDING_UNEXPECTED",
+    ];
+    let to_mute_s = to_mute.join(",");
+    let mut command = Command::new("tidy");
+    command
+        .arg("-errors")
+        .arg("-quiet")
+        .arg("--mute-id") // this option is useful in case we want to mute more warnings
+        .arg("yes")
+        .arg("--mute")
+        .arg(&to_mute_s)
+        .arg(file);
+
+    let Output { status, stderr, .. } = command.output().expect("failed to run tidy command");
+    if status.success() {
+        0
+    } else {
+        let stderr = String::from_utf8(stderr).expect("String::from_utf8 failed...");
+        if stderr.is_empty() && status.code() != Some(2) {
+            0
+        } else {
+            eprintln!(
+                "=> Errors for `{}` (error code: {}) <=",
+                file.display(),
+                status.code().unwrap_or(-1)
+            );
+            eprintln!("{}", stderr);
+            stderr.lines().count()
+        }
+    }
+}
+
+const DOCS_TO_CHECK: &[&str] =
+    &["alloc", "core", "proc_macro", "implementors", "src", "std", "test"];
+
+// Returns the number of files read and the number of errors.
+fn find_all_html_files(dir: &Path) -> (usize, usize) {
+    let mut files_read = 0;
+    let mut errors = 0;
+
+    for entry in walkdir::WalkDir::new(dir).into_iter().filter_entry(|e| {
+        e.depth() != 1
+            || e.file_name()
+                .to_str()
+                .map(|s| DOCS_TO_CHECK.into_iter().any(|d| *d == s))
+                .unwrap_or(false)
+    }) {
+        let entry = entry.expect("failed to read file");
+        if !entry.file_type().is_file() {
+            continue;
+        }
+        let entry = entry.path();
+        if entry.extension().and_then(|s| s.to_str()) == Some("html") {
+            errors += check_html_file(&entry);
+            files_read += 1;
+        }
+    }
+    (files_read, errors)
+}
+
+fn main() -> Result<(), String> {
+    let args = env::args().collect::<Vec<_>>();
+    if args.len() != 2 {
+        return Err(format!("Usage: {} <doc folder>", args[0]));
+    }
+
+    println!("Running HTML checker...");
+
+    let (files_read, errors) = find_all_html_files(&Path::new(&args[1]));
+    println!("Done! Read {} files...", files_read);
+    if errors > 0 {
+        Err(format!("HTML check failed: {} errors", errors))
+    } else {
+        println!("No error found!");
+        Ok(())
+    }
+}