1 files changed, 73 insertions, 0 deletions
diff --git a/go/tools/bazel/bazel.go b/go/tools/bazel/bazel.go
new file mode 100644
index 00000000..d90b0298
--- /dev/null
+++ b/go/tools/bazel/bazel.go
@@ -0,0 +1,73 @@
+// Copyright 2017 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package bazel provides utilities for interacting with the surrounding Bazel environment.
+package bazel
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+const TEST_SRCDIR = "TEST_SRCDIR"
+const TEST_TMPDIR = "TEST_TMPDIR"
+const TEST_WORKSPACE = "TEST_WORKSPACE"
+
+// NewTmpDir creates a new temporary directory in TestTmpDir().
+func NewTmpDir(prefix string) (string, error) {
+	return ioutil.TempDir(TestTmpDir(), prefix)
+}
+
+// TestTmpDir returns the path the Bazel test temp directory.
+// If TEST_TMPDIR is not defined, it returns the OS default temp dir.
+func TestTmpDir() string {
+	if tmp, ok := os.LookupEnv(TEST_TMPDIR); ok {
+		return tmp
+	}
+	return os.TempDir()
+}
+
+// SpliceDelimitedOSArgs is a utility function that scans the os.Args list for
+// entries delimited by the begin and end delimiters (typically the values
+// "-begin_files" and "-end_files" are used). Entries between these delimiters
+// are spliced out of from os.Args and returned to the caller.  If the ordering
+// of -begin_files or -end_files is malformed, error is returned.
+func SpliceDelimitedOSArgs(begin, end string) ([]string, error) {
+	var files []string
+	beginFiles, endFiles := -1, -1
+	for i, arg := range os.Args {
+		if arg == begin {
+			beginFiles = i
+		} else if arg == end {
+			endFiles = i
+			break
+		} else if arg == "--" {
+			break
+		}
+	}
+
+	if beginFiles >= 0 && endFiles < 0 ||
+		beginFiles < 0 && endFiles >= 0 ||
+		beginFiles >= 0 && beginFiles >= endFiles {
+		return nil, fmt.Errorf("error: %s, %s not set together or in order", begin, end)
+	}
+
+	if beginFiles >= 0 {
+		files = os.Args[beginFiles+1 : endFiles]
+		os.Args = append(os.Args[:beginFiles:beginFiles], os.Args[endFiles+1:]...)
+	}
+
+	return files, nil
+}