java/droiddoc.go

// Copyright 2018 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 java

import (
	"android/soong/android"
	"android/soong/java/config"
	"fmt"
	"path/filepath"
	"runtime"
	"strings"

	"github.com/google/blueprint"
)

var (
	javadoc = pctx.AndroidStaticRule("javadoc",
		blueprint.RuleParams{
			Command: `rm -rf "$outDir" "$srcJarDir" "$stubsDir" && mkdir -p "$outDir" "$srcJarDir" "$stubsDir" && ` +
				`${config.ZipSyncCmd} -d $srcJarDir -l $srcJarDir/list -f "*.java" $srcJars && ` +
				`${config.JavadocCmd} -encoding UTF-8 @$out.rsp @$srcJarDir/list ` +
				`$opts $bootclasspathArgs $classpathArgs -sourcepath $sourcepath ` +
				`-d $outDir -quiet  && ` +
				`${config.SoongZipCmd} -write_if_changed -d -o $docZip -C $outDir -D $outDir && ` +
				`${config.SoongZipCmd} -write_if_changed -jar -o $out -C $stubsDir -D $stubsDir $postDoclavaCmds`,
			CommandDeps: []string{
				"${config.ZipSyncCmd}",
				"${config.JavadocCmd}",
				"${config.SoongZipCmd}",
			},
			Rspfile:        "$out.rsp",
			RspfileContent: "$in",
			Restat:         true,
		},
		"outDir", "srcJarDir", "stubsDir", "srcJars", "opts",
		"bootclasspathArgs", "classpathArgs", "sourcepath", "docZip", "postDoclavaCmds")

	apiCheck = pctx.AndroidStaticRule("apiCheck",
		blueprint.RuleParams{
			Command: `( ${config.ApiCheckCmd} -JXmx1024m -J"classpath $classpath" $opts ` +
				`$apiFile $apiFileToCheck $removedApiFile $removedApiFileToCheck ` +
				`&& touch $out ) || (echo -e "$msg" ; exit 38)`,
			CommandDeps: []string{
				"${config.ApiCheckCmd}",
			},
		},
		"classpath", "opts", "apiFile", "apiFileToCheck", "removedApiFile", "removedApiFileToCheck", "msg")

	updateApi = pctx.AndroidStaticRule("updateApi",
		blueprint.RuleParams{
			Command: `( ( cp -f $apiFileToCheck $apiFile && cp -f $removedApiFileToCheck $removedApiFile ) ` +
				`&& touch $out ) || (echo failed to update public API ; exit 38)`,
		},
		"apiFile", "apiFileToCheck", "removedApiFile", "removedApiFileToCheck")

	metalava = pctx.AndroidStaticRule("metalava",
		blueprint.RuleParams{
			Command: `rm -rf "$outDir" "$srcJarDir" "$stubsDir" "$docStubsDir" && ` +
				`mkdir -p "$outDir" "$srcJarDir" "$stubsDir" "$docStubsDir" && ` +
				`${config.ZipSyncCmd} -d $srcJarDir -l $srcJarDir/list -f "*.java" $srcJars && ` +
				`${config.JavaCmd} -jar ${config.MetalavaJar} -encoding UTF-8 -source $javaVersion @$out.rsp @$srcJarDir/list ` +
				`$bootclasspathArgs $classpathArgs -sourcepath $sourcepath --no-banner --color --quiet ` +
				`--stubs $stubsDir $opts && ` +
				`${config.SoongZipCmd} -write_if_changed -d -o $docZip -C $outDir -D $outDir && ` +
				`${config.SoongZipCmd} -write_if_changed -jar -o $out -C $stubsDir -D $stubsDir`,
			CommandDeps: []string{
				"${config.ZipSyncCmd}",
				"${config.JavaCmd}",
				"${config.MetalavaJar}",
				"${config.JavadocCmd}",
				"${config.SoongZipCmd}",
			},
			Rspfile:        "$out.rsp",
			RspfileContent: "$in",
			Restat:         true,
		},
		"outDir", "srcJarDir", "stubsDir", "docStubsDir", "srcJars", "javaVersion", "bootclasspathArgs",
		"classpathArgs", "sourcepath", "opts", "docZip")
)

func init() {
	android.RegisterModuleType("doc_defaults", DocDefaultsFactory)

	android.RegisterModuleType("droiddoc", DroiddocFactory)
	android.RegisterModuleType("droiddoc_host", DroiddocHostFactory)
	android.RegisterModuleType("droiddoc_exported_dir", ExportedDroiddocDirFactory)
	android.RegisterModuleType("javadoc", JavadocFactory)
	android.RegisterModuleType("javadoc_host", JavadocHostFactory)
}

var (
	srcsLibTag = dependencyTag{name: "sources from javalib"}
)

type JavadocProperties struct {
	// list of source files used to compile the Java module.  May be .java, .logtags, .proto,
	// or .aidl files.
	Srcs []string `android:"arch_variant"`

	// list of directories rooted at the Android.bp file that will
	// be added to the search paths for finding source files when passing package names.
	Local_sourcepaths []string

	// list of source files that should not be used to build the Java module.
	// This is most useful in the arch/multilib variants to remove non-common files
	// filegroup or genrule can be included within this property.
	Exclude_srcs []string `android:"arch_variant"`

	// list of java libraries that will be in the classpath.
	Libs []string `android:"arch_variant"`

	// don't build against the framework libraries (legacy-test, core-junit,
	// ext, and framework for device targets)
	No_framework_libs *bool

	// the java library (in classpath) for documentation that provides java srcs and srcjars.
	Srcs_lib *string

	// the base dirs under srcs_lib will be scanned for java srcs.
	Srcs_lib_whitelist_dirs []string

	// the sub dirs under srcs_lib_whitelist_dirs will be scanned for java srcs.
	Srcs_lib_whitelist_pkgs []string

	// If set to false, don't allow this module(-docs.zip) to be exported. Defaults to true.
	Installable *bool

	// if not blank, set to the version of the sdk to compile against
	Sdk_version *string `android:"arch_variant"`

	Aidl struct {
		// Top level directories to pass to aidl tool
		Include_dirs []string

		// Directories rooted at the Android.bp file to pass to aidl tool
		Local_include_dirs []string
	}

	// If not blank, set the java version passed to javadoc as -source
	Java_version *string
}

type ApiToCheck struct {
	// path to the API txt file that the new API extracted from source code is checked
	// against. The path can be local to the module or from other module (via :module syntax).
	Api_file *string

	// path to the API txt file that the new @removed API extractd from source code is
	// checked against. The path can be local to the module or from other module (via
	// :module syntax).
	Removed_api_file *string

	// Arguments to the apicheck tool.
	Args *string
}

type DroiddocProperties struct {
	// directory relative to top of the source tree that contains doc templates files.
	Custom_template *string

	// directories under current module source which contains html/jd files.
	Html_dirs []string

	// set a value in the Clearsilver hdf namespace.
	Hdf []string

	// proofread file contains all of the text content of the javadocs concatenated into one file,
	// suitable for spell-checking and other goodness.
	Proofread_file *string

	// a todo file lists the program elements that are missing documentation.
	// At some point, this might be improved to show more warnings.
	Todo_file *string

	// directory under current module source that provide additional resources (images).
	Resourcesdir *string

	// resources output directory under out/soong/.intermediates.
	Resourcesoutdir *string

	// local files that are used within user customized droiddoc options.
	Arg_files []string

	// user customized droiddoc args.
	// Available variables for substitution:
	//
	//  $(location <label>): the path to the arg_files with name <label>
	Args *string

	// names of the output files used in args that will be generated
	Out []string

	// if set to true, collect the values used by the Dev tools and
	// write them in files packaged with the SDK. Defaults to false.
	Write_sdk_values *bool

	// index.html under current module will be copied to docs out dir, if not null.
	Static_doc_index_redirect *string

	// source.properties under current module will be copied to docs out dir, if not null.
	Static_doc_properties *string

	// a list of files under current module source dir which contains known tags in Java sources.
	// filegroup or genrule can be included within this property.
	Knowntags []string

	// the tag name used to distinguish if the API files belong to public/system/test.
	Api_tag_name *string

	// the generated public API filename by Doclava.
	Api_filename *string

	// the generated public Dex API filename by Doclava.
	Dex_api_filename *string

	// the generated private API filename by Doclava.
	Private_api_filename *string

	// the generated private Dex API filename by Doclava.
	Private_dex_api_filename *string

	// the generated removed API filename by Doclava.
	Removed_api_filename *string

	// the generated removed Dex API filename by Doclava.
	Removed_dex_api_filename *string

	// mapping of dex signatures to source file and line number. This is a temporary property and
	// will be deleted; you probably shouldn't be using it.
	Dex_mapping_filename *string

	// the generated exact API filename by Doclava.
	Exact_api_filename *string

	// the generated proguard filename by Doclava.
	Proguard_filename *string

	// if set to false, don't allow droiddoc to generate stubs source files. Defaults to true.
	Create_stubs *bool

	Check_api struct {
		Last_released ApiToCheck

		Current ApiToCheck
	}

	// if set to true, create stubs through Metalava instead of Doclava. Javadoc/Doclava is
	// currently still used for documentation generation, and will be replaced by Dokka soon.
	Metalava_enabled *bool

	// user can specify the version of previous released API file in order to do compatibility check.
	Metalava_previous_api *string

	// is set to true, Metalava will allow framework SDK to contain annotations.
	Metalava_annotations_enabled *bool

	// a list of top-level directories containing files to merge annotations from.
	Metalava_merge_annotations_dirs []string

	// if set to true, generate docs through Dokka instead of Doclava. Valid only when
	// metalava_enabled is set to true.
	Dokka_enabled *bool
}

//
// Common flags passed down to build rule
//
type droiddocBuilderFlags struct {
	args               string
	bootClasspathArgs  string
	classpathArgs      string
	dokkaClasspathArgs string
	aidlFlags          string

	doclavaStubsFlags string
	doclavaDocsFlags  string
	postDoclavaCmds   string

	metalavaStubsFlags       string
	metalavaAnnotationsFlags string
	metalavaJavadocFlags     string

	metalavaDokkaFlags string
}

func InitDroiddocModule(module android.DefaultableModule, hod android.HostOrDeviceSupported) {
	android.InitAndroidArchModule(module, hod, android.MultilibCommon)
	android.InitDefaultableModule(module)
}

//
// Javadoc
//
type Javadoc struct {
	android.ModuleBase
	android.DefaultableModuleBase

	properties JavadocProperties

	srcJars     android.Paths
	srcFiles    android.Paths
	sourcepaths android.Paths

	docZip      android.WritablePath
	stubsSrcJar android.WritablePath
}

func (j *Javadoc) Srcs() android.Paths {
	return android.Paths{j.stubsSrcJar}
}

func JavadocFactory() android.Module {
	module := &Javadoc{}

	module.AddProperties(&module.properties)

	InitDroiddocModule(module, android.HostAndDeviceSupported)
	return module
}

func JavadocHostFactory() android.Module {
	module := &Javadoc{}

	module.AddProperties(&module.properties)

	InitDroiddocModule(module, android.HostSupported)
	return module
}

var _ android.SourceFileProducer = (*Javadoc)(nil)

func (j *Javadoc) sdkVersion() string {
	return String(j.properties.Sdk_version)
}

func (j *Javadoc) minSdkVersion() string {
	return j.sdkVersion()
}

func (j *Javadoc) addDeps(ctx android.BottomUpMutatorContext) {
	if ctx.Device() {
		sdkDep := decodeSdkDep(ctx, sdkContext(j))
		if sdkDep.useDefaultLibs {
			ctx.AddDependency(ctx.Module(), bootClasspathTag, config.DefaultBootclasspathLibraries...)
			if ctx.Config().TargetOpenJDK9() {
				ctx.AddDependency(ctx.Module(), systemModulesTag, config.DefaultSystemModules)
			}
			if !Bool(j.properties.No_framework_libs) {
				ctx.AddDependency(ctx.Module(), libTag, config.DefaultLibraries...)
			}
		} else if sdkDep.useModule {
			if ctx.Config().TargetOpenJDK9() {
				ctx.AddDependency(ctx.Module(), systemModulesTag, sdkDep.systemModules)
			}
			ctx.AddDependency(ctx.Module(), bootClasspathTag, sdkDep.modules...)
		}
	}

	ctx.AddDependency(ctx.Module(), libTag, j.properties.Libs...)
	if j.properties.Srcs_lib != nil {
		ctx.AddDependency(ctx.Module(), srcsLibTag, *j.properties.Srcs_lib)
	}

	android.ExtractSourcesDeps(ctx, j.properties.Srcs)

	// exclude_srcs may contain filegroup or genrule.
	android.ExtractSourcesDeps(ctx, j.properties.Exclude_srcs)
}

func (j *Javadoc) genWhitelistPathPrefixes(whitelistPathPrefixes map[string]bool) {
	for _, dir := range j.properties.Srcs_lib_whitelist_dirs {
		for _, pkg := range j.properties.Srcs_lib_whitelist_pkgs {
			// convert foo.bar.baz to foo/bar/baz
			pkgAsPath := filepath.Join(strings.Split(pkg, ".")...)
			prefix := filepath.Join(dir, pkgAsPath)
			if _, found := whitelistPathPrefixes[prefix]; !found {
				whitelistPathPrefixes[prefix] = true
			}
		}
	}
}

func (j *Javadoc) collectAidlFlags(ctx android.ModuleContext, deps deps) droiddocBuilderFlags {
	var flags droiddocBuilderFlags

	// aidl flags.
	aidlFlags := j.aidlFlags(ctx, deps.aidlPreprocess, deps.aidlIncludeDirs)
	if len(aidlFlags) > 0 {
		// optimization.
		ctx.Variable(pctx, "aidlFlags", strings.Join(aidlFlags, " "))
		flags.aidlFlags = "$aidlFlags"
	}

	return flags
}

func (j *Javadoc) aidlFlags(ctx android.ModuleContext, aidlPreprocess android.OptionalPath,
	aidlIncludeDirs android.Paths) []string {

	aidlIncludes := android.PathsForModuleSrc(ctx, j.properties.Aidl.Local_include_dirs)
	aidlIncludes = append(aidlIncludes, android.PathsForSource(ctx, j.properties.Aidl.Include_dirs)...)

	var flags []string
	if aidlPreprocess.Valid() {
		flags = append(flags, "-p"+aidlPreprocess.String())
	} else {
		flags = append(flags, android.JoinWithPrefix(aidlIncludeDirs.Strings(), "-I"))
	}

	flags = append(flags, android.JoinWithPrefix(aidlIncludes.Strings(), "-I"))
	flags = append(flags, "-I"+android.PathForModuleSrc(ctx).String())
	if src := android.ExistentPathForSource(ctx, ctx.ModuleDir(), "src"); src.Valid() {
		flags = append(flags, "-I"+src.String())
	}

	return flags
}

func (j *Javadoc) genSources(ctx android.ModuleContext, srcFiles android.Paths,
	flags droiddocBuilderFlags) android.Paths {

	outSrcFiles := make(android.Paths, 0, len(srcFiles))

	for _, srcFile := range srcFiles {
		switch srcFile.Ext() {
		case ".aidl":
			javaFile := genAidl(ctx, srcFile, flags.aidlFlags)
			outSrcFiles = append(outSrcFiles, javaFile)
		default:
			outSrcFiles = append(outSrcFiles, srcFile)
		}
	}

	return outSrcFiles
}

func (j *Javadoc) collectDeps(ctx android.ModuleContext) deps {
	var deps deps

	sdkDep := decodeSdkDep(ctx, sdkContext(j))
	if sdkDep.invalidVersion {
		ctx.AddMissingDependencies(sdkDep.modules)
	} else if sdkDep.useFiles {
		deps.bootClasspath = append(deps.bootClasspath, sdkDep.jars...)
	}

	ctx.VisitDirectDeps(func(module android.Module) {
		otherName := ctx.OtherModuleName(module)
		tag := ctx.OtherModuleDependencyTag(module)

		switch tag {
		case bootClasspathTag:
			if dep, ok := module.(Dependency); ok {
				deps.bootClasspath = append(deps.bootClasspath, dep.ImplementationJars()...)
			} else {
				panic(fmt.Errorf("unknown dependency %q for %q", otherName, ctx.ModuleName()))
			}
		case libTag:
			switch dep := module.(type) {
			case Dependency:
				deps.classpath = append(deps.classpath, dep.ImplementationJars()...)
			case SdkLibraryDependency:
				sdkVersion := j.sdkVersion()
				linkType := javaSdk
				if strings.HasPrefix(sdkVersion, "system_") || strings.HasPrefix(sdkVersion, "test_") {
					linkType = javaSystem
				} else if sdkVersion == "" {
					linkType = javaPlatform
				}
				deps.classpath = append(deps.classpath, dep.ImplementationJars(linkType)...)
			case android.SourceFileProducer:
				checkProducesJars(ctx, dep)
				deps.classpath = append(deps.classpath, dep.Srcs()...)
			default:
				ctx.ModuleErrorf("depends on non-java module %q", otherName)
			}
		case srcsLibTag:
			switch dep := module.(type) {
			case Dependency:
				srcs := dep.(SrcDependency).CompiledSrcs()
				whitelistPathPrefixes := make(map[string]bool)
				j.genWhitelistPathPrefixes(whitelistPathPrefixes)
				for _, src := range srcs {
					if _, ok := src.(android.WritablePath); ok { // generated sources
						deps.srcs = append(deps.srcs, src)
					} else { // select source path for documentation based on whitelist path prefixs.
						for k, _ := range whitelistPathPrefixes {
							if strings.HasPrefix(src.Rel(), k) {
								deps.srcs = append(deps.srcs, src)
								break
							}
						}
					}
				}
				deps.srcJars = append(deps.srcJars, dep.(SrcDependency).CompiledSrcJars()...)
			default:
				ctx.ModuleErrorf("depends on non-java module %q", otherName)
			}
		case systemModulesTag:
			if deps.systemModules != nil {
				panic("Found two system module dependencies")
			}
			sm := module.(*SystemModules)
			if sm.outputFile == nil {
				panic("Missing directory for system module dependency")
			}
			deps.systemModules = sm.outputFile
		}
	})
	// do not pass exclude_srcs directly when expanding srcFiles since exclude_srcs
	// may contain filegroup or genrule.
	srcFiles := ctx.ExpandSources(j.properties.Srcs, j.properties.Exclude_srcs)
	flags := j.collectAidlFlags(ctx, deps)
	srcFiles = j.genSources(ctx, srcFiles, flags)

	// srcs may depend on some genrule output.
	j.srcJars = srcFiles.FilterByExt(".srcjar")
	j.srcJars = append(j.srcJars, deps.srcJars...)

	j.srcFiles = srcFiles.FilterOutByExt(".srcjar")
	j.srcFiles = append(j.srcFiles, deps.srcs...)

	j.docZip = android.PathForModuleOut(ctx, ctx.ModuleName()+"-"+"docs.zip")
	j.stubsSrcJar = android.PathForModuleOut(ctx, ctx.ModuleName()+"-"+"stubs.srcjar")

	if j.properties.Local_sourcepaths == nil {
		j.properties.Local_sourcepaths = append(j.properties.Local_sourcepaths, ".")
	}
	j.sourcepaths = android.PathsForModuleSrc(ctx, j.properties.Local_sourcepaths)

	return deps
}

func (j *Javadoc) DepsMutator(ctx android.BottomUpMutatorContext) {
	j.addDeps(ctx)
}

func (j *Javadoc) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	deps := j.collectDeps(ctx)

	var implicits android.Paths
	implicits = append(implicits, deps.bootClasspath...)
	implicits = append(implicits, deps.classpath...)

	var bootClasspathArgs, classpathArgs string

	javaVersion := getJavaVersion(ctx, String(j.properties.Java_version), sdkContext(j))
	if len(deps.bootClasspath) > 0 {
		var systemModules classpath
		if deps.systemModules != nil {
			systemModules = append(systemModules, deps.systemModules)
		}
		bootClasspathArgs = systemModules.FormJavaSystemModulesPath("--system ", ctx.Device())
		bootClasspathArgs = bootClasspathArgs + " --patch-module java.base=."
	}
	if len(deps.classpath.Strings()) > 0 {
		classpathArgs = "-classpath " + strings.Join(deps.classpath.Strings(), ":")
	}

	implicits = append(implicits, j.srcJars...)

	opts := "-source " + javaVersion + " -J-Xmx1024m -XDignore.symbol.file -Xdoclint:none"

	ctx.Build(pctx, android.BuildParams{
		Rule:           javadoc,
		Description:    "Javadoc",
		Output:         j.stubsSrcJar,
		ImplicitOutput: j.docZip,
		Inputs:         j.srcFiles,
		Implicits:      implicits,
		Args: map[string]string{
			"outDir":            android.PathForModuleOut(ctx, "out").String(),
			"srcJarDir":         android.PathForModuleOut(ctx, "srcjars").String(),
			"stubsDir":          android.PathForModuleOut(ctx, "stubsDir").String(),
			"srcJars":           strings.Join(j.srcJars.Strings(), " "),
			"opts":              opts,
			"bootclasspathArgs": bootClasspathArgs,
			"classpathArgs":     classpathArgs,
			"sourcepath":        strings.Join(j.sourcepaths.Strings(), ":"),
			"docZip":            j.docZip.String(),
		},
	})
}

//
// Droiddoc
//
type Droiddoc struct {
	Javadoc

	properties        DroiddocProperties
	apiFile           android.WritablePath
	dexApiFile        android.WritablePath
	privateApiFile    android.WritablePath
	privateDexApiFile android.WritablePath
	removedApiFile    android.WritablePath
	removedDexApiFile android.WritablePath
	exactApiFile      android.WritablePath
	apiMappingFile    android.WritablePath
	proguardFile      android.WritablePath

	checkCurrentApiTimestamp      android.WritablePath
	updateCurrentApiTimestamp     android.WritablePath
	checkLastReleasedApiTimestamp android.WritablePath

	annotationsZip android.WritablePath

	apiFilePath android.Path
}

type ApiFilePath interface {
	ApiFilePath() android.Path
}

func DroiddocFactory() android.Module {
	module := &Droiddoc{}

	module.AddProperties(&module.properties,
		&module.Javadoc.properties)

	InitDroiddocModule(module, android.HostAndDeviceSupported)
	return module
}

func DroiddocHostFactory() android.Module {
	module := &Droiddoc{}

	module.AddProperties(&module.properties,
		&module.Javadoc.properties)

	InitDroiddocModule(module, android.HostSupported)
	return module
}

func (d *Droiddoc) ApiFilePath() android.Path {
	return d.apiFilePath
}

func (d *Droiddoc) checkCurrentApi() bool {
	if String(d.properties.Check_api.Current.Api_file) != "" &&
		String(d.properties.Check_api.Current.Removed_api_file) != "" {
		return true
	} else if String(d.properties.Check_api.Current.Api_file) != "" {
		panic("check_api.current.removed_api_file: has to be non empty!")
	} else if String(d.properties.Check_api.Current.Removed_api_file) != "" {
		panic("check_api.current.api_file: has to be non empty!")
	}

	return false
}

func (d *Droiddoc) checkLastReleasedApi() bool {
	if String(d.properties.Check_api.Last_released.Api_file) != "" &&
		String(d.properties.Check_api.Last_released.Removed_api_file) != "" {
		return true
	} else if String(d.properties.Check_api.Last_released.Api_file) != "" {
		panic("check_api.last_released.removed_api_file: has to be non empty!")
	} else if String(d.properties.Check_api.Last_released.Removed_api_file) != "" {
		panic("check_api.last_released.api_file: has to be non empty!")
	}

	return false
}

func (d *Droiddoc) DepsMutator(ctx android.BottomUpMutatorContext) {
	d.Javadoc.addDeps(ctx)

	if String(d.properties.Custom_template) != "" {
		ctx.AddDependency(ctx.Module(), droiddocTemplateTag, String(d.properties.Custom_template))
	}

	// arg_files may contains filegroup or genrule.
	android.ExtractSourcesDeps(ctx, d.properties.Arg_files)

	// knowntags may contain filegroup or genrule.
	android.ExtractSourcesDeps(ctx, d.properties.Knowntags)

	if String(d.properties.Static_doc_index_redirect) != "" {
		android.ExtractSourceDeps(ctx, d.properties.Static_doc_index_redirect)
	}

	if String(d.properties.Static_doc_properties) != "" {
		android.ExtractSourceDeps(ctx, d.properties.Static_doc_properties)
	}

	if d.checkCurrentApi() {
		android.ExtractSourceDeps(ctx, d.properties.Check_api.Current.Api_file)
		android.ExtractSourceDeps(ctx, d.properties.Check_api.Current.Removed_api_file)
	}

	if d.checkLastReleasedApi() {
		android.ExtractSourceDeps(ctx, d.properties.Check_api.Last_released.Api_file)
		android.ExtractSourceDeps(ctx, d.properties.Check_api.Last_released.Removed_api_file)
	}

	if String(d.properties.Metalava_previous_api) != "" {
		android.ExtractSourceDeps(ctx, d.properties.Metalava_previous_api)
	}

	if len(d.properties.Metalava_merge_annotations_dirs) != 0 {
		for _, mergeAnnotationsDir := range d.properties.Metalava_merge_annotations_dirs {
			ctx.AddDependency(ctx.Module(), metalavaMergeAnnotationsDirTag, mergeAnnotationsDir)
		}
	}
}

func (d *Droiddoc) initBuilderFlags(ctx android.ModuleContext, implicits *android.Paths,
	deps deps) (droiddocBuilderFlags, error) {
	var flags droiddocBuilderFlags

	*implicits = append(*implicits, deps.bootClasspath...)
	*implicits = append(*implicits, deps.classpath...)

	// continue to use -bootclasspath even if Metalava under -source 1.9 is enabled
	// since it doesn't support system modules yet.
	if len(deps.bootClasspath.Strings()) > 0 {
		// For OpenJDK 8 we can use -bootclasspath to define the core libraries code.
		flags.bootClasspathArgs = deps.bootClasspath.FormJavaClassPath("-bootclasspath")
	}
	flags.classpathArgs = deps.classpath.FormJavaClassPath("-classpath")
	// Dokka doesn't support boocClasspath, so combine these two classpath vars for Dokka.
	dokkaClasspath := classpath{}
	dokkaClasspath = append(dokkaClasspath, deps.bootClasspath...)
	dokkaClasspath = append(dokkaClasspath, deps.classpath...)
	flags.dokkaClasspathArgs = dokkaClasspath.FormJavaClassPath("-classpath")

	argFiles := ctx.ExpandSources(d.properties.Arg_files, nil)
	argFilesMap := map[string]android.Path{}

	for _, f := range argFiles {
		*implicits = append(*implicits, f)
		if _, exists := argFilesMap[f.Rel()]; !exists {
			argFilesMap[f.Rel()] = f
		} else {
			ctx.ModuleErrorf("multiple arg_files for %q, %q and %q",
				f, argFilesMap[f.Rel()], f.Rel())
		}
	}

	var err error
	flags.args, err = android.Expand(String(d.properties.Args), func(name string) (string, error) {
		if strings.HasPrefix(name, "location ") {
			label := strings.TrimSpace(strings.TrimPrefix(name, "location "))
			if f, ok := argFilesMap[label]; ok {
				return f.String(), nil
			} else {
				return "", fmt.Errorf("unknown location label %q", label)
			}
		} else if name == "genDir" {
			return android.PathForModuleGen(ctx).String(), nil
		}
		return "", fmt.Errorf("unknown variable '$(%s)'", name)
	})

	if err != nil {
		ctx.PropertyErrorf("args", "%s", err.Error())
		return droiddocBuilderFlags{}, err
	}
	return flags, nil
}

func (d *Droiddoc) collectDoclavaDocsFlags(ctx android.ModuleContext, implicits *android.Paths,
	jsilver, doclava android.Path) string {

	*implicits = append(*implicits, jsilver)
	*implicits = append(*implicits, doclava)

	var date string
	if runtime.GOOS == "darwin" {
		date = `date -r`
	} else {
		date = `date -d`
	}

	// Droiddoc always gets "-source 1.8" because it doesn't support 1.9 sources.  For modules with 1.9
	// sources, droiddoc will get sources produced by metalava which will have already stripped out the
	// 1.9 language features.
	args := " -source 1.8 -J-Xmx1600m -J-XX:-OmitStackTraceInFastThrow -XDignore.symbol.file " +
		"-doclet com.google.doclava.Doclava -docletpath " + jsilver.String() + ":" + doclava.String() + " " +
		"-hdf page.build " + ctx.Config().BuildId() + "-" + ctx.Config().BuildNumberFromFile() + " " +
		`-hdf page.now "$$(` + date + ` @$$(cat ` + ctx.Config().Getenv("BUILD_DATETIME_FILE") + `) "+%d %b %Y %k:%M")" `

	if String(d.properties.Custom_template) == "" {
		// TODO: This is almost always droiddoc-templates-sdk
		ctx.PropertyErrorf("custom_template", "must specify a template")
	}

	ctx.VisitDirectDepsWithTag(droiddocTemplateTag, func(m android.Module) {
		if t, ok := m.(*ExportedDroiddocDir); ok {
			*implicits = append(*implicits, t.deps...)
			args = args + " -templatedir " + t.dir.String()
		} else {
			ctx.PropertyErrorf("custom_template", "module %q is not a droiddoc_template", ctx.OtherModuleName(m))
		}
	})

	if len(d.properties.Html_dirs) > 0 {
		htmlDir := android.PathForModuleSrc(ctx, d.properties.Html_dirs[0])
		*implicits = append(*implicits, ctx.Glob(htmlDir.Join(ctx, "**/*").String(), nil)...)
		args = args + " -htmldir " + htmlDir.String()
	}

	if len(d.properties.Html_dirs) > 1 {
		htmlDir2 := android.PathForModuleSrc(ctx, d.properties.Html_dirs[1])
		*implicits = append(*implicits, ctx.Glob(htmlDir2.Join(ctx, "**/*").String(), nil)...)
		args = args + " -htmldir2 " + htmlDir2.String()
	}

	if len(d.properties.Html_dirs) > 2 {
		ctx.PropertyErrorf("html_dirs", "Droiddoc only supports up to 2 html dirs")
	}

	knownTags := ctx.ExpandSources(d.properties.Knowntags, nil)
	*implicits = append(*implicits, knownTags...)

	for _, kt := range knownTags {
		args = args + " -knowntags " + kt.String()
	}

	for _, hdf := range d.properties.Hdf {
		args = args + " -hdf " + hdf
	}

	if String(d.properties.Proofread_file) != "" {
		proofreadFile := android.PathForModuleOut(ctx, String(d.properties.Proofread_file))
		args = args + " -proofread " + proofreadFile.String()
	}

	if String(d.properties.Todo_file) != "" {
		// tricky part:
		// we should not compute full path for todo_file through PathForModuleOut().
		// the non-standard doclet will get the full path relative to "-o".
		args = args + " -todo " + String(d.properties.Todo_file)
	}

	if String(d.properties.Resourcesdir) != "" {
		// TODO: should we add files under resourcesDir to the implicits? It seems that
		// resourcesDir is one sub dir of htmlDir
		resourcesDir := android.PathForModuleSrc(ctx, String(d.properties.Resourcesdir))
		args = args + " -resourcesdir " + resourcesDir.String()
	}

	if String(d.properties.Resourcesoutdir) != "" {
		// TODO: it seems -resourceoutdir reference/android/images/ didn't get generated anywhere.
		args = args + " -resourcesoutdir " + String(d.properties.Resourcesoutdir)
	}
	return args
}

func (d *Droiddoc) collectStubsFlags(ctx android.ModuleContext, implicitOutputs *android.WritablePaths) (string, string) {
	var doclavaFlags, MetalavaFlags string
	if d.checkCurrentApi() || d.checkLastReleasedApi() || String(d.properties.Api_filename) != "" {
		d.apiFile = android.PathForModuleOut(ctx, ctx.ModuleName()+"_api.txt")
		doclavaFlags += " -api " + d.apiFile.String()
		MetalavaFlags = MetalavaFlags + " --api " + d.apiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.apiFile)
		d.apiFilePath = d.apiFile
	}

	if d.checkCurrentApi() || d.checkLastReleasedApi() || String(d.properties.Removed_api_filename) != "" {
		d.removedApiFile = android.PathForModuleOut(ctx, ctx.ModuleName()+"_removed.txt")
		doclavaFlags += " -removedApi " + d.removedApiFile.String()
		MetalavaFlags = MetalavaFlags + " --removed-api " + d.removedApiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.removedApiFile)
	}

	if String(d.properties.Private_api_filename) != "" {
		d.privateApiFile = android.PathForModuleOut(ctx, String(d.properties.Private_api_filename))
		doclavaFlags += " -privateApi " + d.privateApiFile.String()
		MetalavaFlags = MetalavaFlags + " --private-api " + d.privateApiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.privateApiFile)
	}

	if String(d.properties.Dex_api_filename) != "" {
		d.dexApiFile = android.PathForModuleOut(ctx, String(d.properties.Dex_api_filename))
		doclavaFlags += " -dexApi " + d.dexApiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.dexApiFile)
	}

	if String(d.properties.Private_dex_api_filename) != "" {
		d.privateDexApiFile = android.PathForModuleOut(ctx, String(d.properties.Private_dex_api_filename))
		doclavaFlags += " -privateDexApi " + d.privateDexApiFile.String()
		MetalavaFlags = MetalavaFlags + " --private-dex-api " + d.privateDexApiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.privateDexApiFile)
	}

	if String(d.properties.Removed_dex_api_filename) != "" {
		d.removedDexApiFile = android.PathForModuleOut(ctx, String(d.properties.Removed_dex_api_filename))
		doclavaFlags += " -removedDexApi " + d.removedDexApiFile.String()
		MetalavaFlags = MetalavaFlags + " --removed-dex-api " + d.removedDexApiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.removedDexApiFile)
	}

	if String(d.properties.Exact_api_filename) != "" {
		d.exactApiFile = android.PathForModuleOut(ctx, String(d.properties.Exact_api_filename))
		doclavaFlags += " -exactApi " + d.exactApiFile.String()
		MetalavaFlags = MetalavaFlags + " --exact-api " + d.exactApiFile.String()
		*implicitOutputs = append(*implicitOutputs, d.exactApiFile)
	}

	if String(d.properties.Dex_mapping_filename) != "" {
		d.apiMappingFile = android.PathForModuleOut(ctx, String(d.properties.Dex_mapping_filename))
		doclavaFlags += " -apiMapping " + d.apiMappingFile.String()
		// Omitted: metalava support
		*implicitOutputs = append(*implicitOutputs, d.apiMappingFile)
	}

	if String(d.properties.Proguard_filename) != "" {
		d.proguardFile = android.PathForModuleOut(ctx, String(d.properties.Proguard_filename))
		doclavaFlags += " -proguard " + d.proguardFile.String()
		// Omitted: metalava support
		*implicitOutputs = append(*implicitOutputs, d.proguardFile)
	}

	if BoolDefault(d.properties.Create_stubs, true) {
		doclavaFlags += " -stubs " + android.PathForModuleOut(ctx, "stubsDir").String()
	}

	if Bool(d.properties.Write_sdk_values) {
		doclavaFlags += " -sdkvalues " + android.PathForModuleOut(ctx, "out").String()
	}
	return doclavaFlags, MetalavaFlags
}

func (d *Droiddoc) getPostDoclavaCmds(ctx android.ModuleContext, implicits *android.Paths) string {
	var cmds string
	if String(d.properties.Static_doc_index_redirect) != "" {
		static_doc_index_redirect := ctx.ExpandSource(String(d.properties.Static_doc_index_redirect),
			"static_doc_index_redirect")
		*implicits = append(*implicits, static_doc_index_redirect)
		cmds = cmds + " && cp " + static_doc_index_redirect.String() + " " +
			android.PathForModuleOut(ctx, "out", "index.html").String()
	}

	if String(d.properties.Static_doc_properties) != "" {
		static_doc_properties := ctx.ExpandSource(String(d.properties.Static_doc_properties),
			"static_doc_properties")
		*implicits = append(*implicits, static_doc_properties)
		cmds = cmds + " && cp " + static_doc_properties.String() + " " +
			android.PathForModuleOut(ctx, "out", "source.properties").String()
	}
	return cmds
}

func (d *Droiddoc) collectMetalavaAnnotationsFlags(
	ctx android.ModuleContext, implicits *android.Paths, implicitOutputs *android.WritablePaths) string {
	var flags string
	if Bool(d.properties.Metalava_annotations_enabled) {
		if String(d.properties.Metalava_previous_api) == "" {
			ctx.PropertyErrorf("metalava_previous_api",
				"has to be non-empty if annotations was enabled!")
		}
		previousApi := ctx.ExpandSource(String(d.properties.Metalava_previous_api),
			"metalava_previous_api")
		*implicits = append(*implicits, previousApi)

		flags += " --include-annotations --migrate-nullness " + previousApi.String()

		d.annotationsZip = android.PathForModuleOut(ctx, ctx.ModuleName()+"_annotations.zip")
		*implicitOutputs = append(*implicitOutputs, d.annotationsZip)

		flags += " --extract-annotations " + d.annotationsZip.String()

		if len(d.properties.Metalava_merge_annotations_dirs) == 0 {
			ctx.PropertyErrorf("metalava_merge_annotations_dirs",
				"has to be non-empty if annotations was enabled!")
		}
		ctx.VisitDirectDepsWithTag(metalavaMergeAnnotationsDirTag, func(m android.Module) {
			if t, ok := m.(*ExportedDroiddocDir); ok {
				*implicits = append(*implicits, t.deps...)
				flags += " --merge-annotations " + t.dir.String()
			} else {
				ctx.PropertyErrorf("metalava_merge_annotations_dirs",
					"module %q is not a metalava merge-annotations dir", ctx.OtherModuleName(m))
			}
		})
		// TODO(tnorbye): find owners to fix these warnings when annotation was enabled.
		flags += " --hide HiddenTypedefConstant --hide SuperfluousPrefix --hide AnnotationExtraction "
	}

	return flags
}

func (d *Droiddoc) collectMetalavaJavadocFlags(ctx android.ModuleContext,
	bootClasspathArgs, classpathArgs, outDir, docStubsDir string) string {
	return " --doc-stubs " + docStubsDir +
		" --write-doc-stubs-source-list " + android.PathForModuleOut(ctx, "doc_stubs.srclist").String() +
		" --generate-documentation ${config.JavadocCmd} -encoding UTF-8 DOC_STUBS_SOURCE_LIST " +
		bootClasspathArgs + " " + classpathArgs + " " + " -sourcepath " +
		docStubsDir + " -quiet -d " + outDir
}

func (d *Droiddoc) collectMetalavaDokkaFlags(ctx android.ModuleContext, implicits *android.Paths,
	classpathArgs, outDir, docStubsDir string) string {
	dokka := android.PathForOutput(ctx, "host", ctx.Config().PrebuiltOS(), "framework", "dokka.jar")
	*implicits = append(*implicits, dokka)

	return " --doc-stubs " + docStubsDir + " --write-doc-stubs-source-list " +
		android.PathForModuleOut(ctx, "doc_stubs.srclist").String() +
		" --generate-documentation ${config.JavaCmd} -jar " + dokka.String() + " " +
		docStubsDir + " " + classpathArgs + " -format dac -dacRoot /reference/kotlin -output " + outDir
}

func (d *Droiddoc) transformMetalava(ctx android.ModuleContext, implicits android.Paths,
	implicitOutputs android.WritablePaths, outDir, docStubsDir, javaVersion,
	bootclasspathArgs, classpathArgs, opts string) {
	ctx.Build(pctx, android.BuildParams{
		Rule:            metalava,
		Description:     "Metalava",
		Output:          d.Javadoc.stubsSrcJar,
		Inputs:          d.Javadoc.srcFiles,
		Implicits:       implicits,
		ImplicitOutputs: implicitOutputs,
		Args: map[string]string{
			"outDir":            outDir,
			"srcJarDir":         android.PathForModuleOut(ctx, "srcjars").String(),
			"stubsDir":          android.PathForModuleOut(ctx, "stubsDir").String(),
			"docStubsDir":       docStubsDir,
			"srcJars":           strings.Join(d.Javadoc.srcJars.Strings(), " "),
			"javaVersion":       javaVersion,
			"bootclasspathArgs": bootclasspathArgs,
			"classpathArgs":     classpathArgs,
			"sourcepath":        strings.Join(d.Javadoc.sourcepaths.Strings(), ":"),
			"docZip":            d.Javadoc.docZip.String(),
			"opts":              opts,
		},
	})
}

func (d *Droiddoc) transformDoclava(ctx android.ModuleContext, implicits android.Paths,
	implicitOutputs android.WritablePaths, bootclasspathArgs, classpathArgs, opts, postDoclavaCmds string) {
	ctx.Build(pctx, android.BuildParams{
		Rule:            javadoc,
		Description:     "Doclava",
		Output:          d.Javadoc.stubsSrcJar,
		Inputs:          d.Javadoc.srcFiles,
		Implicits:       implicits,
		ImplicitOutputs: implicitOutputs,
		Args: map[string]string{
			"outDir":            android.PathForModuleOut(ctx, "out").String(),
			"srcJarDir":         android.PathForModuleOut(ctx, "srcjars").String(),
			"stubsDir":          android.PathForModuleOut(ctx, "stubsDir").String(),
			"srcJars":           strings.Join(d.Javadoc.srcJars.Strings(), " "),
			"opts":              opts,
			"bootclasspathArgs": bootclasspathArgs,
			"classpathArgs":     classpathArgs,
			"sourcepath":        strings.Join(d.Javadoc.sourcepaths.Strings(), ":"),
			"docZip":            d.Javadoc.docZip.String(),
			"postDoclavaCmds":   postDoclavaCmds,
		},
	})
}

func (d *Droiddoc) transformCheckApi(ctx android.ModuleContext, apiFile, removedApiFile android.Path,
	checkApiClasspath classpath, msg, opts string, output android.WritablePath) {
	ctx.Build(pctx, android.BuildParams{
		Rule:        apiCheck,
		Description: "Check API",
		Output:      output,
		Inputs:      nil,
		Implicits: append(android.Paths{apiFile, removedApiFile, d.apiFile, d.removedApiFile},
			checkApiClasspath...),
		Args: map[string]string{
			"classpath":             checkApiClasspath.FormJavaClassPath(""),
			"opts":                  opts,
			"apiFile":               apiFile.String(),
			"apiFileToCheck":        d.apiFile.String(),
			"removedApiFile":        removedApiFile.String(),
			"removedApiFileToCheck": d.removedApiFile.String(),
			"msg": msg,
		},
	})
}

func (d *Droiddoc) transformUpdateApi(ctx android.ModuleContext, apiFile, removedApiFile android.Path,
	output android.WritablePath) {
	ctx.Build(pctx, android.BuildParams{
		Rule:        updateApi,
		Description: "Update API",
		Output:      output,
		Implicits:   append(android.Paths{}, apiFile, removedApiFile, d.apiFile, d.removedApiFile),
		Args: map[string]string{
			"apiFile":               apiFile.String(),
			"apiFileToCheck":        d.apiFile.String(),
			"removedApiFile":        removedApiFile.String(),
			"removedApiFileToCheck": d.removedApiFile.String(),
		},
	})
}

func (d *Droiddoc) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	deps := d.Javadoc.collectDeps(ctx)

	javaVersion := getJavaVersion(ctx, String(d.Javadoc.properties.Java_version), sdkContext(d))
	jsilver := android.PathForOutput(ctx, "host", ctx.Config().PrebuiltOS(), "framework", "jsilver.jar")
	doclava := android.PathForOutput(ctx, "host", ctx.Config().PrebuiltOS(), "framework", "doclava.jar")
	java8Home := ctx.Config().Getenv("ANDROID_JAVA8_HOME")
	checkApiClasspath := classpath{jsilver, doclava, android.PathForSource(ctx, java8Home, "lib/tools.jar")}

	var implicits android.Paths
	implicits = append(implicits, d.Javadoc.srcJars...)

	var implicitOutputs android.WritablePaths
	implicitOutputs = append(implicitOutputs, d.Javadoc.docZip)
	for _, o := range d.properties.Out {
		implicitOutputs = append(implicitOutputs, android.PathForModuleGen(ctx, o))
	}

	flags, err := d.initBuilderFlags(ctx, &implicits, deps)
	if err != nil {
		return
	}

	flags.doclavaStubsFlags, flags.metalavaStubsFlags = d.collectStubsFlags(ctx, &implicitOutputs)
	if Bool(d.properties.Metalava_enabled) {
		flags.metalavaAnnotationsFlags = d.collectMetalavaAnnotationsFlags(ctx, &implicits, &implicitOutputs)
		outDir := android.PathForModuleOut(ctx, "out").String()
		docStubsDir := android.PathForModuleOut(ctx, "docStubsDir").String()
		// TODO(nanzhang): Add a Soong property to handle documentation args.
		if strings.Contains(flags.args, "--generate-documentation") { // enable docs generation
			if Bool(d.properties.Dokka_enabled) {
				flags.metalavaDokkaFlags = d.collectMetalavaDokkaFlags(ctx, &implicits,
					flags.dokkaClasspathArgs, outDir, docStubsDir)
				d.transformMetalava(ctx, implicits, implicitOutputs, outDir, docStubsDir, javaVersion,
					flags.bootClasspathArgs, flags.classpathArgs, flags.metalavaStubsFlags+
						flags.metalavaAnnotationsFlags+" "+strings.Split(flags.args, "--generate-documentation")[0]+
						flags.metalavaDokkaFlags+" "+strings.Split(flags.args, "--generate-documentation")[1])
			} else {
				flags.metalavaJavadocFlags = d.collectMetalavaJavadocFlags(
					ctx, flags.bootClasspathArgs, flags.classpathArgs, outDir, docStubsDir)
				flags.doclavaDocsFlags = d.collectDoclavaDocsFlags(ctx, &implicits, jsilver, doclava)
				d.transformMetalava(ctx, implicits, implicitOutputs, outDir, docStubsDir, javaVersion,
					flags.bootClasspathArgs, flags.classpathArgs, flags.metalavaStubsFlags+
						flags.metalavaAnnotationsFlags+" "+strings.Split(flags.args, "--generate-documentation")[0]+
						flags.metalavaJavadocFlags+flags.doclavaDocsFlags+
						" "+strings.Split(flags.args, "--generate-documentation")[1])
			}
		} else {
			d.transformMetalava(ctx, implicits, implicitOutputs, outDir, docStubsDir, javaVersion,
				flags.bootClasspathArgs, flags.classpathArgs,
				flags.metalavaStubsFlags+flags.metalavaAnnotationsFlags+flags.args)
		}
	} else {
		flags.doclavaDocsFlags = d.collectDoclavaDocsFlags(ctx, &implicits, jsilver, doclava)
		flags.postDoclavaCmds = d.getPostDoclavaCmds(ctx, &implicits)
		d.transformDoclava(ctx, implicits, implicitOutputs, flags.bootClasspathArgs, flags.classpathArgs,
			flags.doclavaDocsFlags+flags.doclavaStubsFlags+" "+flags.args,
			flags.postDoclavaCmds)
	}

	if d.checkCurrentApi() && !ctx.Config().IsPdkBuild() {
		apiFile := ctx.ExpandSource(String(d.properties.Check_api.Current.Api_file),
			"check_api.current.api_file")
		removedApiFile := ctx.ExpandSource(String(d.properties.Check_api.Current.Removed_api_file),
			"check_api.current_removed_api_file")

		if !Bool(d.properties.Metalava_enabled) {
			d.checkCurrentApiTimestamp = android.PathForModuleOut(ctx, "check_current_api.timestamp")
			d.transformCheckApi(ctx, apiFile, removedApiFile, checkApiClasspath,
				fmt.Sprintf(`\n******************************\n`+
					`You have tried to change the API from what has been previously approved.\n\n`+
					`To make these errors go away, you have two choices:\n`+
					`   1. You can add '@hide' javadoc comments to the methods, etc. listed in the\n`+
					`      errors above.\n\n`+
					`   2. You can update current.txt by executing the following command:\n`+
					`         make %s-update-current-api\n\n`+
					`      To submit the revised current.txt to the main Android repository,\n`+
					`      you will need approval.\n`+
					`******************************\n`, ctx.ModuleName()), String(d.properties.Check_api.Current.Args),
				d.checkCurrentApiTimestamp)
		} else {
			// TODO(nanzhang): Refactor below when Metalava support API check.
			if d.apiFile == nil || d.removedApiFile == nil {
				ctx.ModuleErrorf("api_filename and removed_api_filename properties cannot be empty for API check!")
			}
		}

		d.updateCurrentApiTimestamp = android.PathForModuleOut(ctx, "update_current_api.timestamp")
		d.transformUpdateApi(ctx, apiFile, removedApiFile, d.updateCurrentApiTimestamp)
	}

	if d.checkLastReleasedApi() && !ctx.Config().IsPdkBuild() {
		d.checkLastReleasedApiTimestamp = android.PathForModuleOut(ctx, "check_last_released_api.timestamp")

		apiFile := ctx.ExpandSource(String(d.properties.Check_api.Last_released.Api_file),
			"check_api.last_released.api_file")
		removedApiFile := ctx.ExpandSource(String(d.properties.Check_api.Last_released.Removed_api_file),
			"check_api.last_released.removed_api_file")

		d.transformCheckApi(ctx, apiFile, removedApiFile, checkApiClasspath,
			`\n******************************\n`+
				`You have tried to change the API from what has been previously released in\n`+
				`an SDK.  Please fix the errors listed above.\n`+
				`******************************\n`, String(d.properties.Check_api.Last_released.Args),
			d.checkLastReleasedApiTimestamp)
	}
}

//
// Exported Droiddoc Directory
//
var droiddocTemplateTag = dependencyTag{name: "droiddoc-template"}
var metalavaMergeAnnotationsDirTag = dependencyTag{name: "metalava-merge-annotations-dir"}

type ExportedDroiddocDirProperties struct {
	// path to the directory containing Droiddoc related files.
	Path *string
}

type ExportedDroiddocDir struct {
	android.ModuleBase

	properties ExportedDroiddocDirProperties

	deps android.Paths
	dir  android.Path
}

func ExportedDroiddocDirFactory() android.Module {
	module := &ExportedDroiddocDir{}
	module.AddProperties(&module.properties)
	android.InitAndroidModule(module)
	return module
}

func (d *ExportedDroiddocDir) DepsMutator(android.BottomUpMutatorContext) {}

func (d *ExportedDroiddocDir) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	path := android.PathForModuleSrc(ctx, String(d.properties.Path))
	d.dir = path
	d.deps = ctx.Glob(path.Join(ctx, "**/*").String(), nil)
}

//
// Defaults
//
type DocDefaults struct {
	android.ModuleBase
	android.DefaultsModuleBase
}

func (*DocDefaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
}

func (d *DocDefaults) DepsMutator(ctx android.BottomUpMutatorContext) {
}

func DocDefaultsFactory() android.Module {
	module := &DocDefaults{}

	module.AddProperties(
		&JavadocProperties{},
		&DroiddocProperties{},
	)

	android.InitDefaultsModule(module)

	return module
}