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
diff --git a/android/androidmk.go b/android/androidmk.go
new file mode 100644
index 0000000..c8dce0f
--- /dev/null
+++ b/android/androidmk.go
@@ -0,0 +1,215 @@
+// 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 (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+
+	"android/soong"
+
+	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
+)
+
+func init() {
+	soong.RegisterSingletonType("androidmk", AndroidMkSingleton)
+}
+
+type AndroidMkDataProvider interface {
+	AndroidMk() (AndroidMkData, error)
+}
+
+type AndroidMkData struct {
+	Class      string
+	SubName    string
+	OutputFile OptionalPath
+	Disabled   bool
+
+	Custom func(w io.Writer, name, prefix string) error
+
+	Extra []func(w io.Writer, outputFile Path) error
+}
+
+func AndroidMkSingleton() blueprint.Singleton {
+	return &androidMkSingleton{}
+}
+
+type androidMkSingleton struct{}
+
+func (c *androidMkSingleton) GenerateBuildActions(ctx blueprint.SingletonContext) {
+	config := ctx.Config().(Config)
+
+	if !config.EmbeddedInMake() {
+		return
+	}
+
+	ctx.SetNinjaBuildDir(pctx, filepath.Join(config.buildDir, ".."))
+
+	var androidMkModulesList []Module
+
+	ctx.VisitAllModules(func(module blueprint.Module) {
+		if amod, ok := module.(Module); ok {
+			androidMkModulesList = append(androidMkModulesList, amod)
+		}
+	})
+
+	sort.Sort(AndroidModulesByName{androidMkModulesList, ctx})
+
+	transMk := PathForOutput(ctx, "Android"+proptools.String(config.ProductVariables.Make_suffix)+".mk")
+	if ctx.Failed() {
+		return
+	}
+
+	err := translateAndroidMk(ctx, transMk.String(), androidMkModulesList)
+	if err != nil {
+		ctx.Errorf(err.Error())
+	}
+
+	ctx.Build(pctx, blueprint.BuildParams{
+		Rule:     blueprint.Phony,
+		Outputs:  []string{transMk.String()},
+		Optional: true,
+	})
+}
+
+func translateAndroidMk(ctx blueprint.SingletonContext, mkFile string, mods []Module) error {
+	buf := &bytes.Buffer{}
+
+	fmt.Fprintln(buf, "LOCAL_MODULE_MAKEFILE := $(lastword $(MAKEFILE_LIST))")
+
+	for _, mod := range mods {
+		err := translateAndroidMkModule(ctx, buf, mod)
+		if err != nil {
+			os.Remove(mkFile)
+			return err
+		}
+	}
+
+	// Don't write to the file if it hasn't changed
+	if _, err := os.Stat(mkFile); !os.IsNotExist(err) {
+		if data, err := ioutil.ReadFile(mkFile); err == nil {
+			matches := buf.Len() == len(data)
+
+			if matches {
+				for i, value := range buf.Bytes() {
+					if value != data[i] {
+						matches = false
+						break
+					}
+				}
+			}
+
+			if matches {
+				return nil
+			}
+		}
+	}
+
+	return ioutil.WriteFile(mkFile, buf.Bytes(), 0666)
+}
+
+func translateAndroidMkModule(ctx blueprint.SingletonContext, w io.Writer, mod blueprint.Module) error {
+	name := ctx.ModuleName(mod)
+
+	provider, ok := mod.(AndroidMkDataProvider)
+	if !ok {
+		return nil
+	}
+
+	amod := mod.(Module).base()
+	data, err := provider.AndroidMk()
+	if err != nil {
+		return err
+	}
+
+	if !amod.Enabled() {
+		return err
+	}
+
+	if data.SubName != "" {
+		name += "_" + data.SubName
+	}
+
+	hostCross := false
+	if amod.Host() && amod.HostType() != CurrentHostType() {
+		hostCross = true
+	}
+
+	if data.Custom != nil {
+		prefix := ""
+		if amod.Host() {
+			if hostCross {
+				prefix = "HOST_CROSS_"
+			} else {
+				prefix = "HOST_"
+			}
+			if amod.Arch().ArchType != ctx.Config().(Config).HostArches[amod.HostType()][0].ArchType {
+				prefix = "2ND_" + prefix
+			}
+		} else {
+			prefix = "TARGET_"
+			if amod.Arch().ArchType != ctx.Config().(Config).DeviceArches[0].ArchType {
+				prefix = "2ND_" + prefix
+			}
+		}
+
+		return data.Custom(w, name, prefix)
+	}
+
+	if data.Disabled {
+		return nil
+	}
+
+	if !data.OutputFile.Valid() {
+		return err
+	}
+
+	fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)")
+	fmt.Fprintln(w, "LOCAL_PATH :=", filepath.Dir(ctx.BlueprintFile(mod)))
+	fmt.Fprintln(w, "LOCAL_MODULE :=", name)
+	fmt.Fprintln(w, "LOCAL_MODULE_CLASS :=", data.Class)
+	fmt.Fprintln(w, "LOCAL_MULTILIB :=", amod.commonProperties.Compile_multilib)
+	fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", data.OutputFile.String())
+
+	archStr := amod.Arch().ArchType.String()
+	if amod.Host() {
+		if hostCross {
+			fmt.Fprintln(w, "LOCAL_MODULE_HOST_CROSS_ARCH :=", archStr)
+		} else {
+			fmt.Fprintln(w, "LOCAL_MODULE_HOST_ARCH :=", archStr)
+		}
+		fmt.Fprintln(w, "LOCAL_MODULE_HOST_OS :=", amod.HostType().String())
+		fmt.Fprintln(w, "LOCAL_IS_HOST_MODULE := true")
+	} else {
+		fmt.Fprintln(w, "LOCAL_MODULE_TARGET_ARCH :=", archStr)
+	}
+
+	for _, extra := range data.Extra {
+		err = extra(w, data.OutputFile.Path())
+		if err != nil {
+			return err
+		}
+	}
+
+	fmt.Fprintln(w, "include $(BUILD_PREBUILT)")
+
+	return err
+}