1 files changed, 101 insertions, 0 deletions
diff --git a/tools/migration/convert_crosstool_to_starlark.go b/tools/migration/convert_crosstool_to_starlark.go
new file mode 100644
index 0000000..2c31456
--- /dev/null
+++ b/tools/migration/convert_crosstool_to_starlark.go
@@ -0,0 +1,101 @@
+/*
+The convert_crosstool_to_starlark script takes in a CROSSTOOL file and
+generates a Starlark rule.
+
+See https://github.com/bazelbuild/bazel/issues/5380
+
+Example usage:
+bazel run \
+@rules_cc//tools/migration:convert_crosstool_to_starlark -- \
+--crosstool=/path/to/CROSSTOOL \
+--output_location=/path/to/cc_config.bzl
+*/
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/user"
+	"path"
+	"strings"
+
+	// Google internal base/go package, commented out by copybara
+	"log"
+	crosstoolpb "third_party/com/github/bazelbuild/bazel/src/main/protobuf/crosstool_config_go_proto"
+	"github.com/golang/protobuf/proto"
+
+	"tools/migration/crosstooltostarlarklib"
+)
+
+var (
+	crosstoolLocation = flag.String(
+		"crosstool", "", "Location of the CROSSTOOL file")
+	outputLocation = flag.String(
+		"output_location", "", "Location of the output .bzl file")
+)
+
+func toAbsolutePath(pathString string) (string, error) {
+	usr, err := user.Current()
+	if err != nil {
+		return "", err
+	}
+	homeDir := usr.HomeDir
+
+	if strings.HasPrefix(pathString, "~") {
+		return path.Join(homeDir, pathString[1:]), nil
+	}
+
+	if path.IsAbs(pathString) {
+		return pathString, nil
+	}
+
+	workingDirectory := os.Getenv("BUILD_WORKING_DIRECTORY")
+	return path.Join(workingDirectory, pathString), nil
+}
+
+func main() {
+	flag.Parse()
+
+	if *crosstoolLocation == "" {
+		log.Fatalf("Missing mandatory argument 'crosstool'")
+	}
+	crosstoolPath, err := toAbsolutePath(*crosstoolLocation)
+	if err != nil {
+		log.Fatalf("Error while resolving CROSSTOOL location:", err)
+	}
+
+	if *outputLocation == "" {
+		log.Fatalf("Missing mandatory argument 'output_location'")
+	}
+	outputPath, err := toAbsolutePath(*outputLocation)
+	if err != nil {
+		log.Fatalf("Error resolving output location:", err)
+	}
+
+	in, err := ioutil.ReadFile(crosstoolPath)
+	if err != nil {
+		log.Fatalf("Error reading CROSSTOOL file:", err)
+	}
+	crosstool := &crosstoolpb.CrosstoolRelease{}
+	if err := proto.UnmarshalText(string(in), crosstool); err != nil {
+		log.Fatalf("Failed to parse CROSSTOOL:", err)
+	}
+
+	file, err := os.Create(outputPath)
+	if err != nil {
+		log.Fatalf("Error creating output file:", err)
+	}
+	defer file.Close()
+
+	rule, err := crosstooltostarlarklib.Transform(crosstool)
+	if err != nil {
+		log.Fatalf("Error converting CROSSTOOL to a Starlark rule:", err)
+	}
+
+	if _, err := file.WriteString(rule); err != nil {
+		log.Fatalf("Error converting CROSSTOOL to a Starlark rule:", err)
+	}
+	fmt.Println("Success!")
+}