[script] add ccache to build script to speed up builds when possible

.github/workflows/build.yml

@@ -63,6 +63,14 @@ jobs:
       with:
         submodules: true
 
+    - name: ccache
+      uses: hendrikmuhs/[email protected]
+      with:
+        key: ${{ matrix.gcc_ver }}
+
+    - name: Zero ccache stats
+      run: ccache -z
+
     - name: Create LFS file hash list
       run: git -C third_party/silabs/gecko_sdk lfs ls-files -l | cut -d' ' -f1 | sort > .lfs-assets-id
 
@@ -85,6 +93,9 @@ jobs:
         export PATH=${HOME}/.local/${{ matrix.gcc_extract_dir }}/bin:$PATH
         script/test
 
+    - name: Print ccache stats
+      run: ccache -s
+
     - name: Gather SLC generated files
       if: failure()
       run: |

script/bootstrap

@@ -48,6 +48,7 @@ install_packages_apt()
     # Install dependencies
     sudo apt-get update
     apt_packages=(
+        ccache
         coreutils
         git
         git-lfs
@@ -77,6 +78,7 @@ install_packages_brew()
     echo 'Installing script dependencies...'
 
     brew_packages=(
+        ccache
         coreutils
         git
         git-lfs

script/build

@@ -220,7 +220,9 @@ build_soc()
         -DOT_APP_RCP=OFF \
         -DOT_COMPILE_WARNING_AS_ERROR=ON \
         "$@" "${repo_dir}" \
-        --graphviz=graph.dot
+        --graphviz=graph.dot \
+        -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+        -DCMAKE_C_COMPILER_LAUNCHER=ccache
 
     ninja "${soc_targets[@]}"