sysprop/sysprop_library.go

// Copyright (C) 2019 The Android Open Source Project
//
// 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 sysprop

import (
	"fmt"
	"io"
	"path"

	"github.com/google/blueprint"
	"github.com/google/blueprint/proptools"

	"android/soong/android"
	"android/soong/cc"
	"android/soong/java"
)

type dependencyTag struct {
	blueprint.BaseDependencyTag
	name string
}

type syspropGenProperties struct {
	Srcs  []string `android:"path"`
	Scope string
}

type syspropJavaGenRule struct {
	android.ModuleBase

	properties syspropGenProperties

	genSrcjars android.Paths
}

var _ android.OutputFileProducer = (*syspropJavaGenRule)(nil)

var (
	syspropJava = pctx.AndroidStaticRule("syspropJava",
		blueprint.RuleParams{
			Command: `rm -rf $out.tmp && mkdir -p $out.tmp && ` +
				`$syspropJavaCmd --scope $scope --java-output-dir $out.tmp $in && ` +
				`$soongZipCmd -jar -o $out -C $out.tmp -D $out.tmp && rm -rf $out.tmp`,
			CommandDeps: []string{
				"$syspropJavaCmd",
				"$soongZipCmd",
			},
		}, "scope")
)

func init() {
	pctx.HostBinToolVariable("soongZipCmd", "soong_zip")
	pctx.HostBinToolVariable("syspropJavaCmd", "sysprop_java")

	android.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
		ctx.BottomUp("sysprop_deps", syspropDepsMutator).Parallel()
	})
}

func (g *syspropJavaGenRule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	var checkApiFileTimeStamp android.WritablePath

	ctx.VisitDirectDeps(func(dep android.Module) {
		if m, ok := dep.(*syspropLibrary); ok {
			checkApiFileTimeStamp = m.checkApiFileTimeStamp
		}
	})

	for _, syspropFile := range android.PathsForModuleSrc(ctx, g.properties.Srcs) {
		srcJarFile := android.GenPathWithExt(ctx, "sysprop", syspropFile, "srcjar")

		ctx.Build(pctx, android.BuildParams{
			Rule:        syspropJava,
			Description: "sysprop_java " + syspropFile.Rel(),
			Output:      srcJarFile,
			Input:       syspropFile,
			Implicit:    checkApiFileTimeStamp,
			Args: map[string]string{
				"scope": g.properties.Scope,
			},
		})

		g.genSrcjars = append(g.genSrcjars, srcJarFile)
	}
}

func (g *syspropJavaGenRule) OutputFiles(tag string) (android.Paths, error) {
	switch tag {
	case "":
		return g.genSrcjars, nil
	default:
		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
	}
}

func syspropJavaGenFactory() android.Module {
	g := &syspropJavaGenRule{}
	g.AddProperties(&g.properties)
	android.InitAndroidModule(g)
	return g
}

type syspropLibrary struct {
	android.ModuleBase

	properties syspropLibraryProperties

	checkApiFileTimeStamp android.WritablePath
	latestApiFile         android.Path
	currentApiFile        android.Path
	dumpedApiFile         android.WritablePath
}

type syspropLibraryProperties struct {
	// Determine who owns this sysprop library. Possible values are
	// "Platform", "Vendor", or "Odm"
	Property_owner string

	// list of package names that will be documented and publicized as API
	Api_packages []string

	// If set to true, allow this module to be dexed and installed on devices.
	Installable *bool

	// Make this module available when building for recovery
	Recovery_available *bool

	// Make this module available when building for vendor
	Vendor_available *bool

	// list of .sysprop files which defines the properties.
	Srcs []string `android:"path"`
}

var (
	pctx         = android.NewPackageContext("android/soong/sysprop")
	syspropCcTag = dependencyTag{name: "syspropCc"}
)

func init() {
	android.RegisterModuleType("sysprop_library", syspropLibraryFactory)
}

func (m *syspropLibrary) Name() string {
	return m.BaseModuleName() + "_sysprop_library"
}

func (m *syspropLibrary) CcModuleName() string {
	return "lib" + m.BaseModuleName()
}

func (m *syspropLibrary) javaGenModuleName() string {
	return m.BaseModuleName() + "_java_gen"
}

func (m *syspropLibrary) BaseModuleName() string {
	return m.ModuleBase.Name()
}

func (m *syspropLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	baseModuleName := m.BaseModuleName()

	for _, syspropFile := range android.PathsForModuleSrc(ctx, m.properties.Srcs) {
		if syspropFile.Ext() != ".sysprop" {
			ctx.PropertyErrorf("srcs", "srcs contains non-sysprop file %q", syspropFile.String())
		}
	}

	if ctx.Failed() {
		return
	}

	m.currentApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-current.txt")
	m.latestApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-latest.txt")

	// dump API rule
	rule := android.NewRuleBuilder()
	m.dumpedApiFile = android.PathForModuleOut(ctx, "api-dump.txt")
	rule.Command().
		BuiltTool(ctx, "sysprop_api_dump").
		Output(m.dumpedApiFile).
		Inputs(android.PathsForModuleSrc(ctx, m.properties.Srcs))
	rule.Build(pctx, ctx, baseModuleName+"_api_dump", baseModuleName+" api dump")

	// check API rule
	rule = android.NewRuleBuilder()

	// 1. current.txt <-> api_dump.txt
	msg := fmt.Sprintf(`\n******************************\n`+
		`API of sysprop_library %s doesn't match with current.txt\n`+
		`Please update current.txt by:\n`+
		`m %s-dump-api && rm -rf %q && cp -f %q %q\n`+
		`******************************\n`, baseModuleName, baseModuleName,
		m.currentApiFile.String(), m.dumpedApiFile.String(), m.currentApiFile.String())

	rule.Command().
		Text("( cmp").Flag("-s").
		Input(m.dumpedApiFile).
		Input(m.currentApiFile).
		Text("|| ( echo").Flag("-e").
		Flag(`"` + msg + `"`).
		Text("; exit 38) )")

	// 2. current.txt <-> latest.txt
	msg = fmt.Sprintf(`\n******************************\n`+
		`API of sysprop_library %s doesn't match with latest version\n`+
		`Please fix the breakage and rebuild.\n`+
		`******************************\n`, baseModuleName)

	rule.Command().
		Text("( ").
		BuiltTool(ctx, "sysprop_api_checker").
		Input(m.latestApiFile).
		Input(m.currentApiFile).
		Text(" || ( echo").Flag("-e").
		Flag(`"` + msg + `"`).
		Text("; exit 38) )")

	m.checkApiFileTimeStamp = android.PathForModuleOut(ctx, "check_api.timestamp")

	rule.Command().
		Text("touch").
		Output(m.checkApiFileTimeStamp)

	rule.Build(pctx, ctx, baseModuleName+"_check_api", baseModuleName+" check api")
}

func (m *syspropLibrary) AndroidMk() android.AndroidMkData {
	return android.AndroidMkData{
		Custom: func(w io.Writer, name, prefix, moduleDir string, data android.AndroidMkData) {
			// sysprop_library module itself is defined as a FAKE module to perform API check.
			// Actual implementation libraries are created on LoadHookMutator
			fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)")
			fmt.Fprintf(w, "LOCAL_MODULE := %s\n", m.Name())
			fmt.Fprintf(w, "LOCAL_MODULE_CLASS := FAKE\n")
			fmt.Fprintf(w, "LOCAL_MODULE_TAGS := optional\n")
			fmt.Fprintf(w, "include $(BUILD_SYSTEM)/base_rules.mk\n\n")
			fmt.Fprintf(w, "$(LOCAL_BUILT_MODULE): %s\n", m.checkApiFileTimeStamp.String())
			fmt.Fprintf(w, "\ttouch $@\n\n")
			fmt.Fprintf(w, ".PHONY: %s-check-api %s-dump-api\n\n", name, name)

			// dump API rule
			fmt.Fprintf(w, "%s-dump-api: %s\n\n", name, m.dumpedApiFile.String())

			// check API rule
			fmt.Fprintf(w, "%s-check-api: %s\n\n", name, m.checkApiFileTimeStamp.String())
		}}
}

// sysprop_library creates schematized APIs from sysprop description files (.sysprop).
// Both Java and C++ modules can link against sysprop_library, and API stability check
// against latest APIs (see build/soong/scripts/freeze-sysprop-api-files.sh)
// is performed.
func syspropLibraryFactory() android.Module {
	m := &syspropLibrary{}

	m.AddProperties(
		&m.properties,
	)
	android.InitAndroidModule(m)
	android.AddLoadHook(m, func(ctx android.LoadHookContext) { syspropLibraryHook(ctx, m) })
	return m
}

func syspropLibraryHook(ctx android.LoadHookContext, m *syspropLibrary) {
	if len(m.properties.Srcs) == 0 {
		ctx.PropertyErrorf("srcs", "sysprop_library must specify srcs")
	}

	missing_api := false

	for _, txt := range []string{"-current.txt", "-latest.txt"} {
		path := path.Join(ctx.ModuleDir(), "api", m.BaseModuleName()+txt)
		file := android.ExistentPathForSource(ctx, path)
		if !file.Valid() {
			ctx.ModuleErrorf("API file %#v doesn't exist", path)
			missing_api = true
		}
	}

	if missing_api {
		script := "build/soong/scripts/gen-sysprop-api-files.sh"
		p := android.ExistentPathForSource(ctx, script)

		if !p.Valid() {
			panic(fmt.Sprintf("script file %s doesn't exist", script))
		}

		ctx.ModuleErrorf("One or more api files are missing. "+
			"You can create them by:\n"+
			"%s %q %q", script, ctx.ModuleDir(), m.BaseModuleName())
		return
	}

	socSpecific := ctx.SocSpecific()
	deviceSpecific := ctx.DeviceSpecific()
	productSpecific := ctx.ProductSpecific()

	owner := m.properties.Property_owner
	stub := "sysprop-library-stub-"

	switch owner {
	case "Platform":
		// Every partition can access platform-defined properties
		stub += "platform"
	case "Vendor":
		// System can't access vendor's properties
		if !socSpecific && !deviceSpecific && !productSpecific {
			ctx.ModuleErrorf("None of soc_specific, device_specific, product_specific is true. " +
				"System can't access sysprop_library owned by Vendor")
		}
		stub += "vendor"
	case "Odm":
		// Only vendor can access Odm-defined properties
		if !socSpecific && !deviceSpecific {
			ctx.ModuleErrorf("Neither soc_speicifc nor device_specific is true. " +
				"Odm-defined properties should be accessed only in Vendor or Odm")
		}
		stub += "vendor"
	default:
		ctx.PropertyErrorf("property_owner",
			"Unknown value %s: must be one of Platform, Vendor or Odm", owner)
	}

	ccProps := struct {
		Name             *string
		Srcs             []string
		Soc_specific     *bool
		Device_specific  *bool
		Product_specific *bool
		Sysprop          struct {
			Platform *bool
		}
		Header_libs        []string
		Shared_libs        []string
		Required           []string
		Recovery           *bool
		Recovery_available *bool
		Vendor_available   *bool
	}{}

	ccProps.Name = proptools.StringPtr(m.CcModuleName())
	ccProps.Srcs = m.properties.Srcs
	ccProps.Soc_specific = proptools.BoolPtr(socSpecific)
	ccProps.Device_specific = proptools.BoolPtr(deviceSpecific)
	ccProps.Product_specific = proptools.BoolPtr(productSpecific)
	ccProps.Sysprop.Platform = proptools.BoolPtr(owner == "Platform")
	ccProps.Header_libs = []string{"libbase_headers"}
	ccProps.Shared_libs = []string{"liblog"}
	ccProps.Recovery_available = m.properties.Recovery_available
	ccProps.Vendor_available = m.properties.Vendor_available

	ctx.CreateModule(cc.LibraryFactory, &ccProps)

	// internal scope contains all properties
	// public scope only contains public properties
	// use public if the owner is different from client
	scope := "internal"
	isProduct := ctx.ProductSpecific()
	isVendor := ctx.SocSpecific()
	isOwnerPlatform := owner == "Platform"

	if isProduct {
		// product can't own any sysprop_library now, so product must use public scope
		scope = "public"
	} else if isVendor && !isOwnerPlatform {
		// vendor and odm can't use system's internal property.
		scope = "public"
	}

	javaGenProps := struct {
		Srcs  []string
		Scope string
		Name  *string
	}{
		Srcs:  m.properties.Srcs,
		Scope: scope,
		Name:  proptools.StringPtr(m.javaGenModuleName()),
	}

	ctx.CreateModule(syspropJavaGenFactory, &javaGenProps)

	javaProps := struct {
		Name             *string
		Srcs             []string
		Soc_specific     *bool
		Device_specific  *bool
		Product_specific *bool
		Required         []string
		Sdk_version      *string
		Installable      *bool
		Libs             []string
	}{}

	javaProps.Name = proptools.StringPtr(m.BaseModuleName())
	javaProps.Srcs = []string{":" + *javaGenProps.Name}
	javaProps.Soc_specific = proptools.BoolPtr(socSpecific)
	javaProps.Device_specific = proptools.BoolPtr(deviceSpecific)
	javaProps.Product_specific = proptools.BoolPtr(productSpecific)
	javaProps.Installable = m.properties.Installable
	javaProps.Sdk_version = proptools.StringPtr("core_current")
	javaProps.Libs = []string{stub}

	ctx.CreateModule(java.LibraryFactory, &javaProps)
}

func syspropDepsMutator(ctx android.BottomUpMutatorContext) {
	if m, ok := ctx.Module().(*syspropLibrary); ok {
		ctx.AddReverseDependency(m, nil, m.javaGenModuleName())
	}
}