diff --git a/cc/util.go b/cc/util.go
new file mode 100644
index 0000000..8703cfb
--- /dev/null
+++ b/cc/util.go
@@ -0,0 +1,96 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// 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 cc
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+// Efficiently converts a list of include directories to a single string
+// of cflags with -I prepended to each directory.
+func includeDirsToFlags(dirs []string) string {
+	return joinWithPrefix(dirs, "-I")
+}
+
+func ldDirsToFlags(dirs []string) string {
+	return joinWithPrefix(dirs, "-L")
+}
+
+func libNamesToFlags(names []string) string {
+	return joinWithPrefix(names, "-l")
+}
+
+func joinWithPrefix(strs []string, prefix string) string {
+	if len(strs) == 0 {
+		return ""
+	}
+
+	if len(strs) == 1 {
+		return prefix + strs[0]
+	}
+
+	n := len(" ") * (len(strs) - 1)
+	for _, s := range strs {
+		n += len(prefix) + len(s)
+	}
+
+	ret := make([]byte, 0, n)
+	for i, s := range strs {
+		if i != 0 {
+			ret = append(ret, ' ')
+		}
+		ret = append(ret, prefix...)
+		ret = append(ret, s...)
+	}
+	return string(ret)
+}
+
+func inList(s string, list []string) bool {
+	for _, l := range list {
+		if l == s {
+			return true
+		}
+	}
+
+	return false
+}
+
+var libNameRegexp = regexp.MustCompile(`^lib(.*)$`)
+
+func moduleToLibName(module string) (string, error) {
+	matches := libNameRegexp.FindStringSubmatch(module)
+	if matches == nil {
+		return "", fmt.Errorf("Library module name %s does not start with lib", module)
+	}
+	return matches[1], nil
+}
+
+func ccFlagsToBuilderFlags(in ccFlags) builderFlags {
+	return builderFlags{
+		globalFlags: strings.Join(in.globalFlags, " "),
+		asFlags:     strings.Join(in.asFlags, " "),
+		cFlags:      strings.Join(in.cFlags, " "),
+		conlyFlags:  strings.Join(in.conlyFlags, " "),
+		cppFlags:    strings.Join(in.cppFlags, " "),
+		ldFlags:     strings.Join(in.ldFlags, " "),
+		ldLibs:      strings.Join(in.ldLibs, " "),
+		incFlags:    includeDirsToFlags(in.includeDirs),
+		nocrt:       in.nocrt,
+		toolchain:   in.toolchain,
+		clang:       in.clang,
+	}
+}