fix some warnings

.github/workflows/coverage.yml

@@ -8,6 +8,8 @@ jobs:
     name: "coverage"
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: Install lcov by Homebrew
       run: brew install lcov
     - name: Build && Test && Upload

.github/workflows/darwin.yml

@@ -16,6 +16,8 @@ jobs:
     name: "xcode-${{matrix.config.xcode}}"
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: Select Xcode
       run: sudo xcode-select --switch "/Applications/Xcode_${{matrix.config.xcode}}.app"
     - name: Build && Test

.github/workflows/linux.yml

@@ -14,6 +14,7 @@ jobs:
         - { os: "ubuntu-20.04", cc: "gcc-8", cxx: "g++-8" }
         - { os: "ubuntu-20.04", cc: "gcc-9", cxx: "g++-9" }
         - { os: "ubuntu-20.04", cc: "gcc-10", cxx: "g++-10" }
+        - { os: "ubuntu-20.04", cc: "clang-7", cxx: "clang++-7" }
         - { os: "ubuntu-20.04", cc: "clang-8", cxx: "clang++-8" }
         - { os: "ubuntu-20.04", cc: "clang-9", cxx: "clang++-9" }
         - { os: "ubuntu-20.04", cc: "clang-10", cxx: "clang++-10" }
@@ -23,6 +24,8 @@ jobs:
       run: sudo apt-get -y install "${{matrix.config.cc}}" "${{matrix.config.cxx}}"
     - name: Checkout
       uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: Build && Test
       run: .ci/build_linux.sh
       env: { CC: "${{matrix.config.cc}}", CXX: "${{matrix.config.cxx}}" }

.github/workflows/windows.yml

@@ -17,5 +17,7 @@ jobs:
     name: "${{matrix.config.vs}} ${{matrix.config.arch}}"
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: recursive
     - name: Build && Test
       run: .ci\build_windows_${{matrix.config.arch}}.bat