Rename common to android

Rename the "common" package to "android", because common is too
generic.  Also removes all android.Android naming stutter.

Ran:
gomvpkg -from 'android/soong/common' -to 'android/soong/android'
gorename -from '"android/soong/android".AndroidModuleContext' -to 'ModuleContext'
gorename -from '"android/soong/android".AndroidBaseContext' -to 'BaseContext'
gorename -from '"android/soong/android".AndroidModuleBase' -to 'ModuleBase'
gorename -from '"android/soong/android".AndroidBottomUpMutatorContext' -to 'BottomUpMutatorContext'
gorename -from '"android/soong/android".AndroidTopDownMutatorContext' -to 'TopDownMutatorContext'
gorename -from '"android/soong/android".AndroidModule' -to 'Module'

Change-Id: I3b23590b8ce7c8a1ea1139411d84a53163288da7

android/glob.go

@@ -0,0 +1,120 @@
+// 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 android
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/google/blueprint"
+
+	"android/soong/glob"
+)
+
+// This file supports globbing source files in Blueprints files.
+//
+// The build.ninja file needs to be regenerated any time a file matching the glob is added
+// or removed.  The naive solution is to have the build.ninja file depend on all the
+// traversed directories, but this will cause the regeneration step to run every time a
+// non-matching file is added to a traversed directory, including backup files created by
+// editors.
+//
+// The solution implemented here optimizes out regenerations when the directory modifications
+// don't match the glob by having the build.ninja file depend on an intermedate file that
+// is only updated when a file matching the glob is added or removed.  The intermediate file
+// depends on the traversed directories via a depfile.  The depfile is used to avoid build
+// errors if a directory is deleted - a direct dependency on the deleted directory would result
+// in a build failure with a "missing and no known rule to make it" error.
+
+var (
+	globCmd = filepath.Join("${bootstrap.BinDir}", "soong_glob")
+
+	// globRule rule traverses directories to produce a list of files that match $glob
+	// and writes it to $out if it has changed, and writes the directories to $out.d
+	globRule = pctx.StaticRule("globRule",
+		blueprint.RuleParams{
+			Command:     fmt.Sprintf(`%s -o $out $excludes "$glob"`, globCmd),
+			CommandDeps: []string{globCmd},
+			Description: "glob $glob",
+
+			Restat:  true,
+			Deps:    blueprint.DepsGCC,
+			Depfile: "$out.d",
+		},
+		"glob", "excludes")
+)
+
+func hasGlob(in []string) bool {
+	for _, s := range in {
+		if glob.IsGlob(s) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// The subset of ModuleContext and SingletonContext needed by Glob
+type globContext interface {
+	Build(pctx blueprint.PackageContext, params blueprint.BuildParams)
+	AddNinjaFileDeps(deps ...string)
+}
+
+func Glob(ctx globContext, outDir string, globPattern string, excludes []string) ([]string, error) {
+	fileListFile := filepath.Join(outDir, "glob", globToString(globPattern)+".glob")
+	depFile := fileListFile + ".d"
+
+	// Get a globbed file list, and write out fileListFile and depFile
+	files, err := glob.GlobWithDepFile(globPattern, fileListFile, depFile, excludes)
+	if err != nil {
+		return nil, err
+	}
+
+	GlobRule(ctx, globPattern, excludes, fileListFile, depFile)
+
+	// Make build.ninja depend on the fileListFile
+	ctx.AddNinjaFileDeps(fileListFile)
+
+	return files, nil
+}
+
+func GlobRule(ctx globContext, globPattern string, excludes []string,
+	fileListFile, depFile string) {
+
+	// Create a rule to rebuild fileListFile if a directory in depFile changes.  fileListFile
+	// will only be rewritten if it has changed, preventing unnecesary build.ninja regenerations.
+	ctx.Build(pctx, blueprint.BuildParams{
+		Rule:    globRule,
+		Outputs: []string{fileListFile},
+		Args: map[string]string{
+			"glob":     globPattern,
+			"excludes": JoinWithPrefixAndQuote(excludes, "-e "),
+		},
+	})
+}
+
+func globToString(glob string) string {
+	ret := ""
+	for _, c := range glob {
+		if c >= 'a' && c <= 'z' ||
+			c >= 'A' && c <= 'Z' ||
+			c >= '0' && c <= '9' ||
+			c == '_' || c == '-' || c == '/' {
+			ret += string(c)
+		}
+	}
+
+	return ret
+}