Add support to extend commands bpfix and androidmk

Allows our partners to maintain partner-specific fixes in their repos. Converts most of androidmk into a library similar to bpfix. Makes some methods and types public for use by extended versions.

Bug:140727544
Test: Ran unit test cases &&
  ran test conversions with sample
Change-Id: I7e1fbf3a6a7a8bd47334f43fe3eb68cbbd3426c1
diff --git a/bpfix/cmd/bpfix.go b/bpfix/cmd/bpfix.go
deleted file mode 100644
index ccdae16..0000000
--- a/bpfix/cmd/bpfix.go
+++ /dev/null
@@ -1,189 +0,0 @@
-// Copyright 2017 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.
-
-// This file provides a command-line interface to bpfix
-
-// TODO(jeffrygaston) should this file be consolidated with bpfmt.go?
-
-package main
-
-import (
-	"bytes"
-	"flag"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"path/filepath"
-
-	"github.com/google/blueprint/parser"
-
-	"android/soong/bpfix/bpfix"
-)
-
-var (
-	// main operation modes
-	list   = flag.Bool("l", false, "list files whose formatting differs from bpfmt's")
-	write  = flag.Bool("w", false, "write result to (source) file instead of stdout")
-	doDiff = flag.Bool("d", false, "display diffs instead of rewriting files")
-)
-
-var (
-	exitCode = 0
-)
-
-func report(err error) {
-	fmt.Fprintln(os.Stderr, err)
-	exitCode = 2
-}
-
-func openAndProcess(filename string, out io.Writer, fixRequest bpfix.FixRequest) error {
-	f, err := os.Open(filename)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-	return processFile(filename, f, out, fixRequest)
-}
-
-// If in == nil, the source is the contents of the file with the given filename.
-func processFile(filename string, in io.Reader, out io.Writer, fixRequest bpfix.FixRequest) error {
-	// load the input file
-	src, err := ioutil.ReadAll(in)
-	if err != nil {
-		return err
-	}
-	r := bytes.NewBuffer(append([]byte(nil), src...))
-	file, errs := parser.Parse(filename, r, parser.NewScope(nil))
-	if len(errs) > 0 {
-		for _, err := range errs {
-			fmt.Fprintln(os.Stderr, err)
-		}
-		return fmt.Errorf("%d parsing errors", len(errs))
-	}
-
-	// compute and apply any requested fixes
-	fixer := bpfix.NewFixer(file)
-	file, err = fixer.Fix(fixRequest)
-	if err != nil {
-		return err
-	}
-
-	// output the results
-	res, err := parser.Print(file)
-	if err != nil {
-		return err
-	}
-	if !bytes.Equal(src, res) {
-		// contents have changed
-		if *list {
-			fmt.Fprintln(out, filename)
-		}
-		if *write {
-			err = ioutil.WriteFile(filename, res, 0644)
-			if err != nil {
-				return err
-			}
-		}
-		if *doDiff {
-			data, err := diff(src, res)
-			if err != nil {
-				return fmt.Errorf("computing diff: %s", err)
-			}
-			fmt.Printf("diff %s bpfix/%s\n", filename, filename)
-			out.Write(data)
-		}
-	}
-	if !*list && !*write && !*doDiff {
-		_, err = out.Write(res)
-	}
-	return err
-}
-
-func makeFileVisitor(fixRequest bpfix.FixRequest) func(string, os.FileInfo, error) error {
-	return func(path string, f os.FileInfo, err error) error {
-		if err == nil && (f.Name() == "Blueprints" || f.Name() == "Android.bp") {
-			err = openAndProcess(path, os.Stdout, fixRequest)
-		}
-		if err != nil {
-			report(err)
-		}
-		return nil
-	}
-}
-
-func walkDir(path string, fixRequest bpfix.FixRequest) {
-	filepath.Walk(path, makeFileVisitor(fixRequest))
-}
-
-func main() {
-	flag.Parse()
-
-	fixRequest := bpfix.NewFixRequest().AddAll()
-
-	if flag.NArg() == 0 {
-		if *write {
-			fmt.Fprintln(os.Stderr, "error: cannot use -w with standard input")
-			exitCode = 2
-			return
-		}
-		if err := processFile("<standard input>", os.Stdin, os.Stdout, fixRequest); err != nil {
-			report(err)
-		}
-		return
-	}
-
-	for i := 0; i < flag.NArg(); i++ {
-		path := flag.Arg(i)
-		switch dir, err := os.Stat(path); {
-		case err != nil:
-			report(err)
-		case dir.IsDir():
-			walkDir(path, fixRequest)
-		default:
-			if err := openAndProcess(path, os.Stdout, fixRequest); err != nil {
-				report(err)
-			}
-		}
-	}
-}
-
-func diff(b1, b2 []byte) (data []byte, err error) {
-	f1, err := ioutil.TempFile("", "bpfix")
-	if err != nil {
-		return
-	}
-	defer os.Remove(f1.Name())
-	defer f1.Close()
-
-	f2, err := ioutil.TempFile("", "bpfix")
-	if err != nil {
-		return
-	}
-	defer os.Remove(f2.Name())
-	defer f2.Close()
-
-	f1.Write(b1)
-	f2.Write(b2)
-
-	data, err = exec.Command("diff", "-u", f1.Name(), f2.Name()).CombinedOutput()
-	if len(data) > 0 {
-		// diff exits with a non-zero status when the files don't match.
-		// Ignore that failure as long as we get output.
-		err = nil
-	}
-	return
-
-}
diff --git a/bpfix/cmd/main.go b/bpfix/cmd/main.go
new file mode 100644
index 0000000..8ca16b4
--- /dev/null
+++ b/bpfix/cmd/main.go
@@ -0,0 +1,25 @@
+// Copyright 2017 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.
+
+// This file provides a wrapper to the bpfix command-line library
+
+package main
+
+import (
+	"android/soong/bpfix/bpfix/cmd"
+)
+
+func main() {
+	cmd.Run()
+}