Auto merge of rust-lang#134907 - Kobzol:rustc-dev-guide-josh, r=ehuss

Turn rustc-dev-guide into a Josh subtree

Discussed on [Zulip](https://rust-lang.zulipchat.com/#narrow/channel/196385-t-compiler.2Fwg-rustc-dev-guide/topic/a.20move.20to.20main.20repo.20.28rust-lang.2Frust.29).

Accompanying rustc-dev-guide PR: rust-lang/rustc-dev-guide#2183

I didn't create a bootstrap step for rustc-dev-guide yet, because the rustc-dev-guide version that we currently use in this repo doesn't have linkcheck enabled and that fails tests.

The subtree starts with commit [ad93c5f1c49f2aeb45f7a4954017b1e607df9f5e](rust-lang/rustc-dev-guide@ad93c5f).

What I did:
```
export DIR=src/doc/rustc-dev-guide

# Remove submodule
git submodule status ${DIR}
git submodule deinit ${DIR}
git rm -r --cached ${DIR}
rm -rf ${DIR}
# Remove rustc-dev-guide from .gitmodules
git commit -m"Removed `${DIR}` submodule"

# Import history with josh
git fetch https://github.com/rust-lang/rustc-dev-guide ad93c5f1c49f2aeb45f7a4954017b1e607df9f5e
josh-filter ':prefix=src/doc/rustc-dev-guide' FETCH_HEAD
git merge --allow-unrelated FILTERED_HEAD

# A few follow-up cleanup commits
```

r? ehuss

Author: bors

.gitmodules

@@ -22,10 +22,6 @@
 	path = library/stdarch
 	url = https://github.com/rust-lang/stdarch.git
 	shallow = true
-[submodule "src/doc/rustc-dev-guide"]
-	path = src/doc/rustc-dev-guide
-	url = https://github.com/rust-lang/rustc-dev-guide.git
-	shallow = true
 [submodule "src/doc/edition-guide"]
 	path = src/doc/edition-guide
 	url = https://github.com/rust-lang/edition-guide.git

src/bootstrap/src/core/build_steps/doc.rs

@@ -63,7 +63,7 @@ macro_rules! book {
 }
 
 // NOTE: When adding a book here, make sure to ALSO build the book by
-// adding a build step in `src/bootstrap/builder.rs`!
+// adding a build step in `src/bootstrap/code/builder/mod.rs`!
 // NOTE: Make sure to add the corresponding submodule when adding a new book.
 // FIXME: Make checking for a submodule automatic somehow (maybe by having a list of all submodules
 // and checking against it?).

src/bootstrap/src/core/build_steps/test.rs

@@ -2525,35 +2525,6 @@ fn markdown_test(builder: &Builder<'_>, compiler: Compiler, markdown: &Path) ->
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct RustcGuide;
-
-impl Step for RustcGuide {
-    type Output = ();
-    const DEFAULT: bool = false;
-    const ONLY_HOSTS: bool = true;
-
-    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/doc/rustc-dev-guide")
-    }
-
-    fn make_run(run: RunConfig<'_>) {
-        run.builder.ensure(RustcGuide);
-    }
-
-    fn run(self, builder: &Builder<'_>) {
-        let relative_path = "src/doc/rustc-dev-guide";
-        builder.require_submodule(relative_path, None);
-
-        let src = builder.src.join(relative_path);
-        let mut rustbook_cmd = builder.tool_cmd(Tool::Rustbook).delay_failure();
-        rustbook_cmd.arg("linkcheck").arg(&src);
-        let toolstate =
-            if rustbook_cmd.run(builder) { ToolState::TestPass } else { ToolState::TestFail };
-        builder.save_toolstate("rustc-dev-guide", toolstate);
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct CrateLibrustc {
     compiler: Compiler,

src/bootstrap/src/core/build_steps/toolstate.rs

@@ -76,10 +76,7 @@ static STABLE_TOOLS: &[(&str, &str)] = &[
 // We do require that we checked whether they build or not on the tools builder,
 // though, as otherwise we will be unable to file an issue if they start
 // failing.
-static NIGHTLY_TOOLS: &[(&str, &str)] = &[
-    ("embedded-book", "src/doc/embedded-book"),
-    // ("rustc-dev-guide", "src/doc/rustc-dev-guide"),
-];
+static NIGHTLY_TOOLS: &[(&str, &str)] = &[("embedded-book", "src/doc/embedded-book")];
 
 fn print_error(tool: &str, submodule: &str) {
     eprintln!();

src/bootstrap/src/core/builder/mod.rs

@@ -951,7 +951,6 @@ impl<'a> Builder<'a> {
                 test::UnstableBook,
                 test::RustcBook,
                 test::LintDocs,
-                test::RustcGuide,
                 test::EmbeddedBook,
                 test::EditionGuide,
                 test::Rustfmt,

src/doc/rustc-dev-guide

@@ -0,0 +1,10 @@
+root = true
+
+[src/*]
+end_of_line = lf
+insert_final_newline = true
+max_line_length = 100
+
+[ci/*.sh]
+indent_style = space
+indent_size = 2

src/doc/rustc-dev-guide/.editorconfig

@@ -0,0 +1,10 @@
+# Set the default behavior, in case people don't have core.autocrlf set.
+* text=auto eol=lf
+
+# git grep shouldn't match entries in huge minified javascript
+*.min.js binary
+
+# Older git versions try to fix line endings on images, this prevents it.
+*.png binary
+*.jpg binary
+*.ico binary

src/doc/rustc-dev-guide/.gitattributes

@@ -0,0 +1,74 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+  schedule:
+    # Run at 18:00 UTC every day
+    - cron: '0 18 * * *'
+
+jobs:
+  ci:
+    if: github.repository == 'rust-lang/rustc-dev-guide'
+    runs-on: ubuntu-latest
+    env:
+      MDBOOK_VERSION: 0.4.21
+      MDBOOK_LINKCHECK2_VERSION: 0.8.1
+      MDBOOK_MERMAID_VERSION: 0.12.6
+      MDBOOK_TOC_VERSION: 0.11.2
+      DEPLOY_DIR: book/html
+      BASE_SHA: ${{ github.event.pull_request.base.sha }}
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          # linkcheck needs the base commit.
+          fetch-depth: 0
+
+      - name: Cache binaries
+        id: mdbook-cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/bin
+          key: ${{ runner.os }}-${{ env.MDBOOK_VERSION }}--${{ env.MDBOOK_LINKCHECK2_VERSION }}--${{ env.MDBOOK_TOC_VERSION }}--${{ env.MDBOOK_MERMAID_VERSION }}
+
+      - name: Cache linkcheck
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/book/linkcheck
+          key: ${{ runner.os }}-${{ hashFiles('./book/linkcheck') }}
+
+      - name: Install latest nightly Rust toolchain
+        if: steps.mdbook-cache.outputs.cache-hit != 'true'
+        run: |
+          rustup update nightly
+          rustup override set nightly
+
+      - name: Install Dependencies
+        if: steps.mdbook-cache.outputs.cache-hit != 'true'
+        run: |
+          cargo install mdbook --version ${{ env.MDBOOK_VERSION }}
+          cargo install mdbook-linkcheck2 --version ${{ env.MDBOOK_LINKCHECK2_VERSION }}
+          cargo install mdbook-toc --version ${{ env.MDBOOK_TOC_VERSION }}
+          cargo install mdbook-mermaid --version ${{ env.MDBOOK_MERMAID_VERSION }}
+
+      - name: Check build
+        run: ENABLE_LINKCHECK=1 mdbook build
+
+      - name: Deploy to gh-pages
+        if: github.event_name == 'push'
+        run: |
+          touch "${{ env.DEPLOY_DIR }}/.nojekyll"
+          cp CNAME "${{ env.DEPLOY_DIR }}"
+          cd "${{ env.DEPLOY_DIR }}"
+          rm -rf .git
+          git init
+          git config user.name "Deploy from CI"
+          git config user.email ""
+          git add .
+          git commit -m "Deploy ${GITHUB_SHA} to gh-pages"
+          git push --quiet -f "https://x-token:${{ secrets.GITHUB_TOKEN }}@github.com/${GITHUB_REPOSITORY}" HEAD:gh-pages

src/doc/rustc-dev-guide/.github/workflows/ci.yml

@@ -0,0 +1,48 @@
+name: Date-Check
+
+on:
+  schedule:
+    # Run at noon UTC every 1st of the month
+    - cron: '00 12 01 * *'
+
+  # Allow manually starting the workflow
+  workflow_dispatch:
+
+jobs:
+  date-check:
+    if: github.repository == 'rust-lang/rustc-dev-guide'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Ensure Rust is up-to-date
+        run: |
+          rustup update stable
+
+      - name: Run `date-check`
+        working-directory: ci/date-check
+        run: |
+          cargo run -- ../../src/ > ../../date-check-output.txt
+
+      - name: Open issue
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+
+            const rawText = fs.readFileSync('date-check-output.txt', { encoding: 'utf8' });
+            const title = rawText.split('\n')[0];
+            if (title != 'empty') {
+                const body = rawText.split('\n').slice(1).join('\n');
+                github.rest.issues.create({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  title,
+                  body,
+                });
+                console.log('Opened issue.');
+            } else {
+                console.log('No dates to triage.');
+            }