Add soong_build primary builder

Initial build logic for building android with soong.  It can build
a variety of C and C++ files for arm/arm64 and host.

Change-Id: I10eb37c2c2a50be6af1bb5fd568c0962b9476bf0

cmd/soong_glob/soong_glob.go

@@ -0,0 +1,56 @@
+// 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.
+
+// soong_glob is the command line tool that checks if the list of files matching a glob has
+// changed, and only updates the output file list if it has changed.  It is used to optimize
+// out build.ninja regenerations when non-matching files are added.  See
+// android/soong/common/glob.go for a longer description.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"android/soong/glob"
+)
+
+var (
+	out = flag.String("o", "", "file to write list of files that match glob")
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: soong_glob -o out glob\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+func main() {
+	flag.Parse()
+
+	if *out == "" {
+		fmt.Fprintln(os.Stderr, "error: -o is required\n")
+		usage()
+	}
+
+	if flag.NArg() != 1 {
+		usage()
+	}
+
+	_, err := glob.GlobWithDepFile(flag.Arg(0), *out, *out+".d")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %s\n", err.Error())
+		os.Exit(1)
+	}
+}