docs: Add latest commit to top of index

Insert `git show --stat HEAD` into the template for the top-level docs,
to make it easy to see what a build was generated for.

Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

.github/workflows/docs.yml

@@ -47,7 +47,6 @@ jobs:
           west build -t rustdoc -b qemu_cortex_m3 docgen
           mkdir rustdocs
           mv build/rust/target/thumbv7m-none-eabi/doc rustdocs/nostd
-          cp docs/top-index.html rustdocs/index.html
 
       - name: Build build documentation
         working-directory: zephyr-lang-rust
@@ -56,6 +55,26 @@ jobs:
           cargo doc
           mv target/doc ../rustdocs/std
 
+      - name: Debug SHA values
+        run: |
+          echo "GITHUB_SHA: $GITHUB_SHA"
+          echo "Pull request head: ${{ github.event.pull_request.head.sha }}"
+          echo "Pull request ref: ${{ github.event.pull_request.head.ref }}"
+
+      - name: Determine commit SHA
+        run: |
+          if [[ "${{ github.event_name }} == "pull_request" ]]; then
+            echo "COMMIT_SHA=${{ github.event.pull_request.head.sha }}" >> $GITHUB_ENV
+          else
+            echo "COMMIT_SHA=${{ github.sha }}" >> $GITHUB_ENV
+          fi
+
+      - name: Inect commit details into top-level commit.
+        working-directory: zephyr-lang-rust
+        env:
+          COMMIT_SHA: "${{ env.COMMIT_SHA }}"
+        run: python3 etc/add-hash.py
+
       - name: Upload docs artifact
         uses: actions/upload-artifact@v4
         with:

docs/top-index.html

@@ -10,5 +10,8 @@ <h1>Documentation Index</h1>
         <li><a href="nostd/zephyr/index.html">zephyr crate Documentation</a></li>
         <li><a href="std/zephyr_build/index.html">zephyr_build support Documentation</a></li>
     </ul>
+    <pre>
+{{COMMIT}}
+    </pre>
 </body>
 </html>

etc/add-hash.py

@@ -0,0 +1,25 @@
+#! /usr/bin/env python
+
+import os
+import subprocess
+
+input = "./docs/top-index.html"
+output = "rustdocs/index.html"
+
+# Get the commit from github (otherwise, we are likely to just see a merge commit.  Default to HEAD
+# if not provided.
+commit_sha = os.getenv("COMMIT_SHA", "HEAD")
+
+try:
+    commit_info = subprocess.check_output(["git", "show", "--stat", "HEAD"], text=True)
+except subprocess.CalledProcessError as e:
+    print(f"Error getting commit info: {e}")
+    commit_info = "Error retrieving commit details.\n"
+
+with open(output, "w") as outfile:
+    with open(input, "r") as file:
+        for line in file:
+            if "{{COMMIT}}" in line:
+                outfile.write(commit_info)
+            else:
+                outfile.write(line)