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 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) BaseModuleName() string {
	return m.ModuleBase.Name()
}

func (m *syspropLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	m.currentApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", m.BaseModuleName()+"-current.txt")
	m.latestApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", m.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, m.BaseModuleName()+"_api_dump", m.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`+
		`rm -rf %q && cp -f %q %q\n`+
		`******************************\n`, m.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`, m.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, m.BaseModuleName()+"_check_api", m.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\n\n", name)

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

			// "make {sysprop_library}" should also build the C++ library
			fmt.Fprintf(w, "%s: %s\n\n", name, m.CcModuleName())
		}}
}

// 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"}

	// add sysprop_library module to perform check API
	ccProps.Required = []string{m.Name()}
	ccProps.Sysprop.Platform = proptools.BoolPtr(owner == "Platform")
	ccProps.Recovery_available = m.properties.Recovery_available
	ccProps.Vendor_available = m.properties.Vendor_available

	ctx.CreateModule(android.ModuleFactoryAdaptor(cc.LibraryFactory), &ccProps)

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

	javaProps.Name = proptools.StringPtr(m.BaseModuleName())
	javaProps.Srcs = m.properties.Srcs
	javaProps.Soc_specific = proptools.BoolPtr(socSpecific)
	javaProps.Device_specific = proptools.BoolPtr(deviceSpecific)
	javaProps.Product_specific = proptools.BoolPtr(productSpecific)
	javaProps.Installable = m.properties.Installable

	// add sysprop_library module to perform check API
	javaProps.Required = []string{m.Name()}
	javaProps.Sdk_version = proptools.StringPtr("core_current")
	javaProps.Sysprop.Platform = proptools.BoolPtr(owner == "Platform")
	javaProps.Libs = []string{stub}

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