Add GitHub Actions build and prerelease workflow

.github/workflows/main.yml

@@ -0,0 +1,139 @@
+name: Build
+
+# Pushes build only on main; other branches are built through their pull request.
+# This avoids duplicate runs: concurrency groups are per ref, and a push
+# (refs/heads/x) and a pull_request (refs/pull/N/merge) never share a ref.
+on:
+  push:
+    branches: [main]
+    paths-ignore:
+      - '**.md'
+      - 'LICENSE'
+      - '.github/ISSUE_TEMPLATE/**'
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - 'LICENSE'
+      - '.github/ISSUE_TEMPLATE/**'
+  workflow_dispatch:
+
+# Least privilege by default; only the prerelease job elevates to contents: write.
+permissions:
+  contents: read
+
+concurrency:
+  group: build-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  build:
+    name: VoodooHDA
+    runs-on: macos-15-intel
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+      - name: Install MacKernelSDK
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+        with:
+          repository: acidanthera/MacKernelSDK
+          ref: 3f750085caa17ec3a7880f11c11bf4f48cd6a164
+          path: MacKernelSDK
+      - name: Build VoodooHDA for macOS
+        env:
+          CONFIGURATION: Release
+        run: |
+          set -euo pipefail
+          mkdir -p logs
+          xcodebuild -project tranc/VoodooHDA_BS.xcodeproj -target VoodooHDA \
+            -configuration "$CONFIGURATION" -jobs 3 ARCHS=x86_64 \
+            SYMROOT="$PWD/build/products" OBJROOT="$PWD/build/obj" \
+            CODE_SIGNING_ALLOWED=NO GIT_COMMIT="_$(git rev-parse --short HEAD)" \
+            build > logs/VoodooHDA.log 2>&1 || { tail -100 logs/VoodooHDA.log; exit 1; }
+      - name: Package VoodooHDA kernel extension
+        env:
+          CONFIGURATION: Release
+        run: |
+          set -euo pipefail
+          mkdir -p artifacts
+          products="$PWD/build/products/$CONFIGURATION"
+          version=$(awk '/CURRENT_PROJECT_VERSION =/ {gsub(/;/, "", $3); print $3; exit}' tranc/VoodooHDA_BS.xcodeproj/project.pbxproj)
+          if [[ -z "$version" ]]; then
+            echo "::error::Could not determine CURRENT_PROJECT_VERSION from project.pbxproj"
+            exit 1
+          fi
+          short_sha=$(git rev-parse --short HEAD)
+          configuration=$(printf '%s' "$CONFIGURATION" | tr '[:lower:]' '[:upper:]')
+          suffix="v$version-$configuration-alpha-$short_sha"
+          ditto -c -k --keepParent "$products/VoodooHDA.kext" "artifacts/VoodooHDA-$suffix.zip"
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: VoodooHDA
+          path: artifacts/VoodooHDA-*.zip
+          if-no-files-found: error
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        if: always()
+        with:
+          name: build-logs
+          path: logs
+
+  prerelease:
+    name: Publish development build
+    needs: build
+    # Only publish from trusted triggers on main. Pull requests (including from
+    # forks) never reach this job, so untrusted code cannot get a write token.
+    if: github.ref == 'refs/heads/main' && (github.event_name == 'push' || github.event_name == 'workflow_dispatch')
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+        with:
+          # Keep in sync with `git log -5` in the release notes step below.
+          fetch-depth: 5
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        with:
+          name: VoodooHDA
+          path: artifacts
+      - name: Publish alpha artifacts
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          version=$(awk '/CURRENT_PROJECT_VERSION =/ {gsub(/;/, "", $3); print $3; exit}' tranc/VoodooHDA_BS.xcodeproj/project.pbxproj)
+          if [[ -z "$version" ]]; then
+            echo "::error::Could not determine CURRENT_PROJECT_VERSION from project.pbxproj"
+            exit 1
+          fi
+          tag="v${version}-alpha"
+          printf '%s\n\n' 'Development build. Hardware validation is required before daily use.' > ReleaseNotes.md
+          # -5 intentionally matches fetch-depth: 5 in the checkout step.
+          git log -5 --format='- %h %s' >> ReleaseNotes.md
+          if gh release view "$tag" --json isPrerelease > current-release.json 2>/dev/null; then
+            # Never replace a stable release with development artifacts.
+            jq -e '.isPrerelease == true' current-release.json > /dev/null
+            gh api --method PATCH "repos/$GITHUB_REPOSITORY/git/refs/tags/$tag" \
+              -f sha="$GITHUB_SHA" -F force=true
+            gh release edit "$tag" --prerelease --notes-file ReleaseNotes.md
+          else
+            gh release create "$tag" --target "$GITHUB_SHA" --prerelease --title "$tag" --notes-file ReleaseNotes.md
+          fi
+          gh release upload "$tag" artifacts/VoodooHDA-*.zip --clobber
+
+          # Remove obsolete assets only after the replacement set has uploaded.
+          gh api "repos/$GITHUB_REPOSITORY/releases/tags/$tag" \
+            --jq '.assets[] | [.id, .name] | @tsv' > release-assets.tsv
+          while IFS=$'\t' read -r asset_id asset_name; do
+            if [[ ! -f "artifacts/$asset_name" ]]; then
+              gh api --method DELETE "repos/$GITHUB_REPOSITORY/releases/assets/$asset_id"
+            fi
+          done < release-assets.tsv
+
+          # Keep exactly one prerelease; stable releases are retained.
+          gh api --paginate "repos/$GITHUB_REPOSITORY/releases" \
+            --jq '.[] | select(.prerelease and (.draft | not)) | .tag_name' > prereleases.txt
+          while IFS= read -r old_tag; do
+            if [[ "$old_tag" != "$tag" ]]; then
+              gh release delete "$old_tag" --yes --cleanup-tag
+            fi
+          done < prereleases.txt