[github] cache clang builds

Summary:
Use the cache action to cache the clang build instead of the
facebook-clang-plugins releases.

- the facebook-clang-plugins repo is no longer by infer so its clang
  will soon be out of date

- much simpler to use the cache action

- build clang before setting opam: this is unfortunate but needed to
  ensure there is enough space on GitHub's machines to build clang...

- install ninja on Linux + Mac machines for faster and less OOM-y builds

Reviewed By: martintrojer

Differential Revision: D24160876

fbshipit-source-id: 705e06151

.github/workflows/install.yml

@@ -21,53 +21,50 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v2
 
-      - name: Restore opam cache
-        uses: actions/cache@v2
-        with:
-          path: ~/.opam
-          key: opam-${{ runner.os }}-${{ hashFiles('opam.locked') }}
-
-      - name: Use OCaml ${{ matrix.ocaml-version }}
-        uses: avsm/setup-ocaml@v1
-        with:
-          ocaml-version: ${{ matrix.ocaml-version }}
+      - name: Install Required Apt Packages for Ubuntu
+        run: |
+          sudo apt install libmpfr-dev libsqlite3-dev ninja-build
+          sudo apt clean
+        if: runner.os == 'Linux'
 
       - name: Install Required Brew Packages for MacOS
-        run: brew install pkg-config automake jq
+        run: brew install automake jq ninja pkg-config
         if: runner.os == 'macOS'
 
-      - name: Install Required Apt Packages for Ubuntu
-        run: sudo apt-get install libmpfr-dev libsqlite3-dev
-        if: runner.os == 'Linux'
-
-      - name: Fetch clang Release
+      - name: Compute hash of clang installation
+        id: clang-hash
         run: |
-          REPO="facebook/facebook-clang-plugins"
-          URL="https://api.github.com/repos/$REPO"
-
-          CLANGFILE="clang-install-${{ matrix.os }}.tar.gz"
+          echo "::set-output name=value::$(./facebook-clang-plugins/clang/setup.sh --clang-hash)"
 
-          RELEASE_INFO="$(curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" "$URL/releases/latest")"
-          if ! ASSET_ID="$(jq ".assets | map(select(.name == \"$CLANGFILE\"))[0].id" <<< "$RELEASE_INFO")"; then
-              echo "$RELEASE_INFO"
-              exit 1
-          fi
+      - name: Attempt to get clang from the cache
+        id: cache-clang
+        uses: actions/cache@v2
+        with:
+          path: facebook-clang-plugins/clang/install
+          key: clang-${{ runner.os }}-${{ steps.clang-hash.outputs.value }}
 
-          if [[ -z "$ASSET_ID" || "$ASSET_ID" == "null" ]]; then
-              echo "Could not find asset ID" >&2
-              exit 1
-          fi
+      - name: Record that the clang cache was hit
+        if: steps.cache-clang.outputs.cache-hit == 'true'
+        run: ./facebook-clang-plugins/clang/setup.sh --only-record-install
 
-          curl -J -L "$URL/releases/assets/$ASSET_ID" \
-              -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-              -H "Accept: application/octet-stream" \
-              -o "$CLANGFILE"
+      - name: Build clang on cache misses
+        if: steps.cache-clang.outputs.cache-hit != 'true'
+        run: |
+          ./facebook-clang-plugins/clang/src/prepare_clang_src.sh
+          ./facebook-clang-plugins/clang/setup.sh --ninja --sequential-link
 
-      - run: tar -xzf clang-install-${{ matrix.os }}.tar.gz -C facebook-clang-plugins/clang/
+      - name: Attempt to get opam tree from the cache
+        uses: actions/cache@v2
+        with:
+          path: ~/.opam
+          key: opam-${{ runner.os }}-${{ hashFiles('opam.locked') }}
 
-      - run: ./facebook-clang-plugins/clang/setup.sh --only-record-install
+      - name: Use OCaml ${{ matrix.ocaml-version }}
+        uses: avsm/setup-ocaml@v1
+        with:
+          ocaml-version: ${{ matrix.ocaml-version }}
 
-      - run: ./build-infer.sh -y all
+      - run: ./build-infer.sh --yes all
 
       - run: make install
         if: runner.os == 'macOS'