tools: Parallelize ./tools/format

10x speed improvement on my 3990x machine

Change-Id: Ie4b2377719e9a25860ec05bb7649aa652d26ccf0
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/113022
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Ben Clayton <bclayton@google.com>

tools/format

@@ -13,9 +13,29 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-find src -name "*.h"  -exec clang_format.py -i {} \;
-find src -name "*.cc"  -exec clang_format.py -i {} \;
-find src -name "*.cpp"  -exec clang_format.py -i {} \;
-find src -name "*.m"  -exec clang_format.py -i {} \;
-find src -name "*.mm"  -exec clang_format.py -i {} \;
-find include -name "*.h"  -exec clang_format.py -i {} \;
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd )"
+ROOT_DIR="$( cd "${SCRIPT_DIR}/.." >/dev/null 2>&1 && pwd )"
+
+set -e  # fail on error
+
+if ! command -v clang_format.py &> /dev/null; then
+    echo "clang_format.py not found on PATH"
+    exit 1
+fi
+
+FILES=""
+FILES+="`find src -name "*.h"` "
+FILES+="`find src -name "*.cc"` "
+FILES+="`find src -name "*.cpp"` "
+FILES+="`find src -name "*.m"` "
+FILES+="`find src -name "*.mm"` "
+FILES+="`find include -name "*.h"` "
+
+if command -v go &> /dev/null; then
+    # Go is installed. Run cpplint in parallel for speed wins
+    ${SCRIPT_DIR}/run run-parallel  \
+         clang_format.py -i         \
+         $ -- $FILES
+else
+    clang_format.py -i $FILES
+fi

tools/lint

@@ -24,8 +24,12 @@ if ! command -v cpplint.py &> /dev/null; then
 fi
 
 FILTER="-runtime/references"
-FILES="`find src/tint -type f` `find src/tint/cmd -type f`"
-FILES+="`find tools/src -type f` `find src/tint/cmd -type f`"
+
+FILES=""
+FILES+="`find src/tint -type f` "
+FILES+="`find src/tint/cmd -type f` "
+FILES+="`find tools/src -type f` "
+FILES+="`find src/tint/cmd -type f` "
 
 # Note, there is currently no verbosity level set for cpplint.py which means
 # it will use the default level of 1. This level needs to match what is in the
@@ -33,7 +37,7 @@ FILES+="`find tools/src -type f` `find src/tint/cmd -type f`"
 
 if command -v go &> /dev/null; then
     # Go is installed. Run cpplint in parallel for speed wins
-    go run $SCRIPT_DIR/src/cmd/run-parallel/main.go \
+    ${SCRIPT_DIR}/run run-parallel                  \
          --only-print-failures                      \
          cpplint.py                                 \
          --root=$ROOT_DIR                           \

tools/src/cmd/run-parallel/main.go

@@ -75,6 +75,7 @@ func run() error {
 
 	taskIndices := make(chan int, 64)
 	type result struct {
+		cmd    string
 		msg    string
 		failed bool
 	}
@@ -93,7 +94,7 @@ func run() error {
 				}
 				success, out := invoke(exe, taskArgs)
 				if !success || !*onlyPrintFailures {
-					results[idx] = result{out, !success}
+					results[idx] = result{fmt.Sprint(append([]string{exe}, taskArgs...)), out, !success}
 				}
 			}
 		}()
@@ -109,7 +110,7 @@ func run() error {
 	failed := false
 	for _, result := range results {
 		if result.msg != "" {
-			fmt.Println(result.msg)
+			fmt.Printf("'%v' returned %v\n", result.cmd, result.msg)
 		}
 		failed = failed || result.failed
 	}