[Github] Add steps to build clang docs to CI

[boomanaiden154]

Recently, support for building the LLVM documentation within Github actions landed, allowing for easy testing of the docs both pre and post landing. This patch extends that functionality to clang and adds in additional support to the docs Github workflow to only build the docs for the subproject whose documentation has been touched.

[llvmbot]

@llvm/pr-subscribers-github-workflow

Author: Aiden Grossman (boomanaiden154)

Changes

Recently, support for building the LLVM documentation within Github actions landed, allowing for easy testing of the docs both pre and post landing. This patch extends that functionality to clang and adds in additional support to the docs Github workflow to only build the docs for the subproject whose documentation has been touched.

---

Full diff: https://github.com/llvm/llvm-project/pull/69550.diff

1 Files Affected:

• (modified) .github/workflows/docs.yml (+22-3)

diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 5133309eb8cf948..315f8d59037ef1d 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -14,9 +14,11 @@ on:
       - 'main'
     paths:
       - 'llvm/docs/**'
+      - 'clang/docs/**'
   pull_request:
     paths:
       - 'llvm/docs/**'
+      - 'clang/docs/**'
 
 jobs:
   check-docs-build:
@@ -39,10 +41,27 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y cmake ninja-build
-      - name: Build docs
+      - name: Get subprojects that have doc changes
+        id: docs-changed-subprojects
+        uses: tj-actions/changed-files@v39
+        with:
+          files_yaml: |
+            llvm:
+              - 'llvm/docs/**'
+            clang:
+              - 'clang/docs/**'
+      - name: Build LLVM docs
+        if: steps.docs-changed-subprojects.outputs.llvm_any_changed == 'true'
         run: |
-          mkdir build
-          cd build
+          mkdir llvm-build
+          cd llvm-build
           cmake -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_SPHINX=ON -DSPHINX_OUTPUT_HTML=ON -DSPHINX_OUTPUT_MAN=ON ../llvm
           TZ=UTC ninja docs-llvm-html docs-llvm-man
+      - name: Build Clang docs
+        if: steps.docs-changed-subprojects.outputs.clang_any_changed == 'true'
+        run: |
+          mkdir clang-build
+          cd clang-build
+          cmake -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_SPHINX=ON -DSPHINX_OUTPUT_HTML=ON -DSPHINX_OUTPUT_MAN=ON ../llvm
+          TZ=UTC ninja docs-clang-html docs-clang-man
 

[boomanaiden154]

I've set everything up in the same job for now mostly because it was simple. We can split it into multiple jobs if necessary, but I don't think many patches touch the docs of multiple subprojects, and those that do still won't run into any problems with the job taking too long. From my testing on my fork, building both the LLVM and clang docs takes under 10 minutes, even with clang having to build clang-tblgen.

[boomanaiden154]

This will fix #65725.

[tstellar]

Thank you this looks great. LGTM.

[boomanaiden154]

Thank you for the review! I'll probably post something on discourse soon too to get attention for other subprojects that might want this.