[Github] Add flang docs to Github actions

[boomanaiden154]

This patch enables building the flang docs in Github actions to enable rapid iteration in PRs and to catch docs build failures more easily before merge/after merge. This patch currently doesn't fail for Sphinx warnings, but the intention is to enable this functionality once the flang docs are fixed to build without warnings after the transition to Myst.

[llvmbot]

@llvm/pr-subscribers-github-workflow

Author: Aiden Grossman (boomanaiden154)

Changes

This patch enables building the flang docs in Github actions to enable rapid iteration in PRs and to catch docs build failures more easily before merge/after merge. This patch currently doesn't fail for Sphinx warnings, but the intention is to enable this functionality once the flang docs are fixed to build without warnings after the transition to Myst.

---

Full diff: https://github.com/llvm/llvm-project/pull/70530.diff

1 Files Affected:

• (modified) .github/workflows/docs.yml (+11)

diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index e6af2f41167e0a1..40cd3da1f8120c3 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -21,6 +21,7 @@ on:
       - 'libcxx/docs/**'
       - 'libc/docs/**'
       - 'lld/docs/**'
+      - 'flang/docs/**'
   pull_request:
     paths:
       - 'llvm/docs/**'
@@ -31,6 +32,7 @@ on:
       - 'libcxx/docs/**'
       - 'libc/docs/**'
       - 'lld/docs/**'
+      - 'flang/docs/**'
 
 jobs:
   check-docs-build:
@@ -67,6 +69,8 @@ jobs:
               - 'libc/docs/**'
             lld:
               - 'lld/docs/**'
+            flang:
+              - 'flang/docs/**'
       - name: Fetch LLVM sources (PR)
         if: ${{ github.event_name == 'pull_request' }}
         uses: actions/checkout@v4
@@ -125,4 +129,11 @@ jobs:
         run: |
           cmake -B lld-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="lld" -DLLVM_ENABLE_SPHINX=ON ./llvm
           TZ=UTC ninja -C lld-build docs-lld-html
+      - name: Build Flang docs
+        if: steps.docs-changed-subprojects.outputs.flang_any_changed == 'true'
+        # TODO(boomanaiden154): Remove the SPHINX_WARNINGS_AS_ERRORS from the
+        # CMake invocation once the warnings in the flang docs build are fixed.
+        run: |
+          cmake -B flang-build -GNinja -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;mlir;flang" -DLLVM_ENABLE_SPHINX=ON -DSPHINX_WARNINGS_AS_ERRORS=OFF ./llvm
+          TZ=UTC ninja -C flang-build docs-flang-html docs-flang-man