I can haz sccache for WASI CI?

Author: gpshead

.github/workflows/reusable-wasi.yml

@@ -18,6 +18,7 @@ jobs:
       WASI_SDK_PATH: /opt/wasi-sdk
       CROSS_BUILD_PYTHON: cross-build/build
       CROSS_BUILD_WASI: cross-build/wasm32-wasip1
+      SCCACHE_GHA_ENABLED: "true"
     steps:
     - uses: actions/checkout@v4
     # No problem resolver registered as one doesn't currently exist for Clang.
@@ -37,13 +38,8 @@ jobs:
         mkdir ${{ env.WASI_SDK_PATH }} && \
         curl -s -S --location https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-${{ env.WASI_SDK_VERSION }}/wasi-sdk-${{ env.WASI_SDK_VERSION }}.0-x86_64-linux.tar.gz | \
         tar --strip-components 1 --directory ${{ env.WASI_SDK_PATH }} --extract --gunzip
-    - name: "Configure ccache action"
-      uses: hendrikmuhs/[email protected]
-      with:
-        save: ${{ github.event_name == 'push' }}
-        max-size: "200M"
-    - name: "Add ccache to PATH"
-      run: echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
+    - name: Start sccache-cache
+      uses: mozilla-actions/[email protected]
     - name: "Install Python"
       uses: actions/setup-python@v5
       with:

Tools/wasm/wasi.py

@@ -173,12 +173,23 @@ def wasi_sdk_env(context):
     env = {"CC": "clang", "CPP": "clang-cpp", "CXX": "clang++",
            "AR": "llvm-ar", "RANLIB": "ranlib"}
 
+    # sccache available? wire it up!
+    # used in GHA CI via .github/workflows/reusable-wasi.yaml
+    if subprocess.call(["sccache", "--version"], stderr=subprocess.DEVNULL) == 0:
+        env["CC"] = f'sccache {env["CC"]}'
+        env["CPP"] = f'sccache {env["CPP"]}'
+        env["CXX"] = f'sccache {env["CXX"]}'
+
     for env_var, binary_name in list(env.items()):
         env[env_var] = os.fsdecode(wasi_sdk_path / "bin" / binary_name)
 
+    compiler_env_names = ("CC", "CPP", "CXX")
     if wasi_sdk_path != pathlib.Path("/opt/wasi-sdk"):
-        for compiler in ["CC", "CPP", "CXX"]:
+        for compiler in compiler_env_names:
             env[compiler] += f" --sysroot={sysroot}"
+    if subprocess.call(("sccache", "--version"), stderr=subprocess.DEVNULL) == 0:
+        for compiler in compiler_env_names:
+            env[compiler] = 'sccache ' + env[compiler]
 
     env["PKG_CONFIG_PATH"] = ""
     env["PKG_CONFIG_LIBDIR"] = os.pathsep.join(