android/soong_config_modules.go - SHIFTPHONES/android_build_soong - Gitiles

 // Copyright 2019 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

 // This file provides module types that implement wrapper module types that add conditionals on
 // Soong config variables.

 import (
 	"fmt"
 	"path/filepath"
 	"reflect"
 	"strings"
 	"sync"
 	"text/scanner"

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

 	"android/soong/android/soongconfig"
 )

 func init() {
 	RegisterSoongConfigModuleBuildComponents(InitRegistrationContext)
 }

 func RegisterSoongConfigModuleBuildComponents(ctx RegistrationContext) {
 	ctx.RegisterModuleType("soong_config_module_type_import", SoongConfigModuleTypeImportFactory)
 	ctx.RegisterModuleType("soong_config_module_type", SoongConfigModuleTypeFactory)
 	ctx.RegisterModuleType("soong_config_string_variable", SoongConfigStringVariableDummyFactory)
 	ctx.RegisterModuleType("soong_config_bool_variable", SoongConfigBoolVariableDummyFactory)
 	ctx.RegisterModuleType("soong_config_value_variable", SoongConfigValueVariableDummyFactory)
 }

 var PrepareForTestWithSoongConfigModuleBuildComponents = FixtureRegisterWithContext(RegisterSoongConfigModuleBuildComponents)

 type soongConfigModuleTypeImport struct {
 	ModuleBase
 	properties soongConfigModuleTypeImportProperties
 }

 type soongConfigModuleTypeImportProperties struct {
 	From         string
 	Module_types []string
 }

 // soong_config_module_type_import imports module types with conditionals on Soong config
 // variables from another Android.bp file.  The imported module type will exist for all
 // modules after the import in the Android.bp file.
 //
 // Each soong_config_variable supports an additional value `conditions_default`. The properties
 // specified in `conditions_default` will only be used under the following conditions:
 //   bool variable: the variable is unspecified or not set to a true value
 //   value variable: the variable is unspecified
 //   list variable: the variable is unspecified
 //   string variable: the variable is unspecified or the variable is set to a string unused in the
 //                    given module. For example, string variable `test` takes values: "a" and "b",
 //                    if the module contains a property `a` and `conditions_default`, when test=b,
 //                    the properties under `conditions_default` will be used. To specify that no
 //                    properties should be amended for `b`, you can set `b: {},`.
 //
 // For example, an Android.bp file could have:
 //
 //     soong_config_module_type_import {
 //         from: "device/acme/Android.bp",
 //         module_types: ["acme_cc_defaults"],
 //     }
 //
 //     acme_cc_defaults {
 //         name: "acme_defaults",
 //         cflags: ["-DGENERIC"],
 //         soong_config_variables: {
 //             board: {
 //                 soc_a: {
 //                     cflags: ["-DSOC_A"],
 //                 },
 //                 soc_b: {
 //                     cflags: ["-DSOC_B"],
 //                 },
 //                 conditions_default: {
 //                     cflags: ["-DSOC_DEFAULT"],
 //                 },
 //             },
 //             feature: {
 //                 cflags: ["-DFEATURE"],
 //                 conditions_default: {
 //                     cflags: ["-DFEATURE_DEFAULT"],
 //                 },
 //             },
 //             width: {
 //                 cflags: ["-DWIDTH=%s"],
 //                 conditions_default: {
 //                     cflags: ["-DWIDTH=DEFAULT"],
 //                 },
 //             },
 //             impl: {
 //                 srcs: ["impl/%s"],
 //                 conditions_default: {
 //                     srcs: ["impl/default.cpp"],
 //                 },
 //             },
 //         },
 //     }
 //
 //     cc_library {
 //         name: "libacme_foo",
 //         defaults: ["acme_defaults"],
 //         srcs: ["*.cpp"],
 //     }
 //
 // And device/acme/Android.bp could have:
 //
 //     soong_config_module_type {
 //         name: "acme_cc_defaults",
 //         module_type: "cc_defaults",
 //         config_namespace: "acme",
 //         variables: ["board"],
 //         bool_variables: ["feature"],
 //         value_variables: ["width"],
 //         list_variables: ["impl"],
 //         properties: ["cflags", "srcs"],
 //     }
 //
 //     soong_config_string_variable {
 //         name: "board",
 //         values: ["soc_a", "soc_b", "soc_c"],
 //     }
 //
 // If an acme BoardConfig.mk file contained:
 //     $(call add_sonng_config_namespace, acme)
 //     $(call add_soong_config_var_value, acme, board, soc_a)
 //     $(call add_soong_config_var_value, acme, feature, true)
 //     $(call add_soong_config_var_value, acme, width, 200)
 //     $(call add_soong_config_var_value, acme, impl, foo.cpp bar.cpp)
 //
 // Then libacme_foo would build with cflags "-DGENERIC -DSOC_A -DFEATURE -DWIDTH=200" and srcs
 // ["*.cpp", "impl/foo.cpp", "impl/bar.cpp"].
 //
 // Alternatively, if acme BoardConfig.mk file contained:
 //
 //     SOONG_CONFIG_NAMESPACES += acme
 //     SOONG_CONFIG_acme += \
 //         board \
 //         feature \
 //
 //     SOONG_CONFIG_acme_feature := false
 //
 // Then libacme_foo would build with cflags:
 //   "-DGENERIC -DSOC_DEFAULT -DFEATURE_DEFAULT -DSIZE=DEFAULT"
 // and with srcs:
 //   ["*.cpp", "impl/default.cpp"].
 //
 // Similarly, if acme BoardConfig.mk file contained:
 //
 //     SOONG_CONFIG_NAMESPACES += acme
 //     SOONG_CONFIG_acme += \
 //         board \
 //         feature \
 //
 //     SOONG_CONFIG_acme_board := soc_c
 //     SOONG_CONFIG_acme_impl := foo.cpp bar.cpp
 //
 // Then libacme_foo would build with cflags:
 //   "-DGENERIC -DSOC_DEFAULT -DFEATURE_DEFAULT -DSIZE=DEFAULT"
 // and with srcs:
 //   ["*.cpp", "impl/foo.cpp", "impl/bar.cpp"].
 //

 func SoongConfigModuleTypeImportFactory() Module {
 	module := &soongConfigModuleTypeImport{}

 	module.AddProperties(&module.properties)
 	AddLoadHook(module, func(ctx LoadHookContext) {
 		importModuleTypes(ctx, module.properties.From, module.properties.Module_types...)
 	})

 	initAndroidModuleBase(module)
 	return module
 }

 func (m *soongConfigModuleTypeImport) Name() string {
 	// The generated name is non-deterministic, but it does not
 	// matter because this module does not emit any rules.
 	return soongconfig.CanonicalizeToProperty(m.properties.From) +
 		"soong_config_module_type_import_" + fmt.Sprintf("%p", m)
 }

 func (*soongConfigModuleTypeImport) Namespaceless()                            {}
 func (*soongConfigModuleTypeImport) GenerateAndroidBuildActions(ModuleContext) {}

 // Create dummy modules for soong_config_module_type and soong_config_*_variable

 type soongConfigModuleTypeModule struct {
 	ModuleBase
 	properties soongconfig.ModuleTypeProperties
 }

 // soong_config_module_type defines module types with conditionals on Soong config
 // variables.  The new module type will exist for all modules after the definition
 // in an Android.bp file, and can be imported into other Android.bp files using
 // soong_config_module_type_import.
 //
 // Each soong_config_variable supports an additional value `conditions_default`. The properties
 // specified in `conditions_default` will only be used under the following conditions:
 //
 //	bool variable: the variable is unspecified or not set to a true value
 //	value variable: the variable is unspecified
 //	list variable: the variable is unspecified
 //	string variable: the variable is unspecified or the variable is set to a string unused in the
 //	                 given module. For example, string variable `test` takes values: "a" and "b",
 //	                 if the module contains a property `a` and `conditions_default`, when test=b,
 //	                 the properties under `conditions_default` will be used. To specify that no
 //	                 properties should be amended for `b`, you can set `b: {},`.
 //
 // For example, an Android.bp file could have:
 //
 //	soong_config_module_type {
 //	    name: "acme_cc_defaults",
 //	    module_type: "cc_defaults",
 //	    config_namespace: "acme",
 //	    variables: ["board"],
 //	    bool_variables: ["feature"],
 //	    value_variables: ["width"],
 //	    list_variables: ["impl"],
 //	    properties: ["cflags", "srcs"],
 //	}
 //
 //	soong_config_string_variable {
 //	    name: "board",
 //	    values: ["soc_a", "soc_b"],
 //	}
 //
 //	acme_cc_defaults {
 //	    name: "acme_defaults",
 //	    cflags: ["-DGENERIC"],
 //	    soong_config_variables: {
 //	        board: {
 //	            soc_a: {
 //	                cflags: ["-DSOC_A"],
 //	            },
 //	            soc_b: {
 //	                cflags: ["-DSOC_B"],
 //	            },
 //	            conditions_default: {
 //	                cflags: ["-DSOC_DEFAULT"],
 //	            },
 //	        },
 //	        feature: {
 //	            cflags: ["-DFEATURE"],
 //	            conditions_default: {
 //	                cflags: ["-DFEATURE_DEFAULT"],
 //	            },
 //	        },
 //	        width: {
 //	            cflags: ["-DWIDTH=%s"],
 //	            conditions_default: {
 //	                cflags: ["-DWIDTH=DEFAULT"],
 //	            },
 //	        },
 //	        impl: {
 //	            srcs: ["impl/%s"],
 //	            conditions_default: {
 //	                srcs: ["impl/default.cpp"],
 //	            },
 //	        },
 //	    },
 //	}
 //
 //	cc_library {
 //	    name: "libacme_foo",
 //	    defaults: ["acme_defaults"],
 //	    srcs: ["*.cpp"],
 //	}
 //
 // If an acme BoardConfig.mk file contained:
 //
 //	SOONG_CONFIG_NAMESPACES += acme
 //	SOONG_CONFIG_acme += \
 //	    board \
 //	    feature \
 //
 //	SOONG_CONFIG_acme_board := soc_a
 //	SOONG_CONFIG_acme_feature := true
 //	SOONG_CONFIG_acme_width := 200
 //	SOONG_CONFIG_acme_impl := foo.cpp bar.cpp
 //
 // Then libacme_foo would build with cflags "-DGENERIC -DSOC_A -DFEATURE" and srcs
 // ["*.cpp", "impl/foo.cpp", "impl/bar.cpp"].
 func SoongConfigModuleTypeFactory() Module {
 	module := &soongConfigModuleTypeModule{}

 	module.AddProperties(&module.properties)

 	AddLoadHook(module, func(ctx LoadHookContext) {
 		// A soong_config_module_type module should implicitly import itself.
 		importModuleTypes(ctx, ctx.BlueprintsFile(), module.properties.Name)
 	})

 	initAndroidModuleBase(module)

 	return module
 }

 func (m *soongConfigModuleTypeModule) Name() string {
 	return m.properties.Name + fmt.Sprintf("%p", m)
 }
 func (*soongConfigModuleTypeModule) Namespaceless()                                {}
 func (*soongConfigModuleTypeModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

 type soongConfigStringVariableDummyModule struct {
 	ModuleBase
 	properties       soongconfig.VariableProperties
 	stringProperties soongconfig.StringVariableProperties
 }

 type soongConfigBoolVariableDummyModule struct {
 	ModuleBase
 	properties soongconfig.VariableProperties
 }

 type soongConfigValueVariableDummyModule struct {
 	ModuleBase
 	properties soongconfig.VariableProperties
 }

 // soong_config_string_variable defines a variable and a set of possible string values for use
 // in a soong_config_module_type definition.
 func SoongConfigStringVariableDummyFactory() Module {
 	module := &soongConfigStringVariableDummyModule{}
 	module.AddProperties(&module.properties, &module.stringProperties)
 	initAndroidModuleBase(module)
 	return module
 }

 // soong_config_string_variable defines a variable with true or false values for use
 // in a soong_config_module_type definition.
 func SoongConfigBoolVariableDummyFactory() Module {
 	module := &soongConfigBoolVariableDummyModule{}
 	module.AddProperties(&module.properties)
 	initAndroidModuleBase(module)
 	return module
 }

 // soong_config_value_variable defines a variable whose value can be expanded into
 // the value of a string property.
 func SoongConfigValueVariableDummyFactory() Module {
 	module := &soongConfigValueVariableDummyModule{}
 	module.AddProperties(&module.properties)
 	initAndroidModuleBase(module)
 	return module
 }

 func (m *soongConfigStringVariableDummyModule) Name() string {
 	return m.properties.Name + fmt.Sprintf("%p", m)
 }
 func (*soongConfigStringVariableDummyModule) Namespaceless()                                {}
 func (*soongConfigStringVariableDummyModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

 func (m *soongConfigBoolVariableDummyModule) Name() string {
 	return m.properties.Name + fmt.Sprintf("%p", m)
 }
 func (*soongConfigBoolVariableDummyModule) Namespaceless()                                {}
 func (*soongConfigBoolVariableDummyModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

 func (m *soongConfigValueVariableDummyModule) Name() string {
 	return m.properties.Name + fmt.Sprintf("%p", m)
 }
 func (*soongConfigValueVariableDummyModule) Namespaceless()                                {}
 func (*soongConfigValueVariableDummyModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

 // importModuleTypes registers the module factories for a list of module types defined
 // in an Android.bp file. These module factories are scoped for the current Android.bp
 // file only.
 func importModuleTypes(ctx LoadHookContext, from string, moduleTypes ...string) {
 	from = filepath.Clean(from)
 	if filepath.Ext(from) != ".bp" {
 		ctx.PropertyErrorf("from", "%q must be a file with extension .bp", from)
 		return
 	}

 	if strings.HasPrefix(from, "../") {
 		ctx.PropertyErrorf("from", "%q must not use ../ to escape the source tree",
 			from)
 		return
 	}

 	moduleTypeDefinitions := loadSoongConfigModuleTypeDefinition(ctx, from)
 	if moduleTypeDefinitions == nil {
 		return
 	}
 	for _, moduleType := range moduleTypes {
 		if factory, ok := moduleTypeDefinitions[moduleType]; ok {
 			ctx.registerScopedModuleType(moduleType, factory)
 		} else {
 			ctx.PropertyErrorf("module_types", "module type %q not defined in %q",
 				moduleType, from)
 		}
 	}
 }

 // loadSoongConfigModuleTypeDefinition loads module types from an Android.bp file.  It caches the
 // result so each file is only parsed once.
 func loadSoongConfigModuleTypeDefinition(ctx LoadHookContext, from string) map[string]blueprint.ModuleFactory {
 	type onceKeyType string
 	key := NewCustomOnceKey(onceKeyType(filepath.Clean(from)))

 	reportErrors := func(ctx LoadHookContext, filename string, errs ...error) {
 		for _, err := range errs {
 			if parseErr, ok := err.(*parser.ParseError); ok {
 				ctx.Errorf(parseErr.Pos, "%s", parseErr.Err)
 			} else {
 				ctx.Errorf(scanner.Position{Filename: filename}, "%s", err)
 			}
 		}
 	}

 	return ctx.Config().Once(key, func() interface{} {
 		ctx.AddNinjaFileDeps(from)
 		r, err := ctx.Config().fs.Open(from)
 		if err != nil {
 			ctx.PropertyErrorf("from", "failed to open %q: %s", from, err)
 			return (map[string]blueprint.ModuleFactory)(nil)
 		}
 		defer r.Close()

 		mtDef, errs := soongconfig.Parse(r, from)
 		if len(errs) > 0 {
 			reportErrors(ctx, from, errs...)
 			return (map[string]blueprint.ModuleFactory)(nil)
 		}

 		globalModuleTypes := ctx.moduleFactories()

 		factories := make(map[string]blueprint.ModuleFactory)

 		for name, moduleType := range mtDef.ModuleTypes {
 			factory := globalModuleTypes[moduleType.BaseModuleType]
 			if factory != nil {
 				factories[name] = configModuleFactory(factory, moduleType)
 			} else {
 				reportErrors(ctx, from,
 					fmt.Errorf("missing global module type factory for %q", moduleType.BaseModuleType))
 			}
 		}

 		if ctx.Failed() {
 			return (map[string]blueprint.ModuleFactory)(nil)
 		}

 		return factories
 	}).(map[string]blueprint.ModuleFactory)
 }

 // tracingConfig is a wrapper to soongconfig.SoongConfig which records all accesses to SoongConfig.
 type tracingConfig struct {
 	config    soongconfig.SoongConfig
 	boolSet   map[string]bool
 	stringSet map[string]string
 	isSetSet  map[string]bool
 }

 func (c *tracingConfig) Bool(name string) bool {
 	c.boolSet[name] = c.config.Bool(name)
 	return c.boolSet[name]
 }

 func (c *tracingConfig) String(name string) string {
 	c.stringSet[name] = c.config.String(name)
 	return c.stringSet[name]
 }

 func (c *tracingConfig) IsSet(name string) bool {
 	c.isSetSet[name] = c.config.IsSet(name)
 	return c.isSetSet[name]
 }

 func (c *tracingConfig) getTrace() soongConfigTrace {
 	ret := soongConfigTrace{}

 	for k, v := range c.boolSet {
 		ret.Bools = append(ret.Bools, fmt.Sprintf("%q:%t", k, v))
 	}
 	for k, v := range c.stringSet {
 		ret.Strings = append(ret.Strings, fmt.Sprintf("%q:%q", k, v))
 	}
 	for k, v := range c.isSetSet {
 		ret.IsSets = append(ret.IsSets, fmt.Sprintf("%q:%t", k, v))
 	}

 	return ret
 }

 func newTracingConfig(config soongconfig.SoongConfig) *tracingConfig {
 	c := tracingConfig{
 		config:    config,
 		boolSet:   make(map[string]bool),
 		stringSet: make(map[string]string),
 		isSetSet:  make(map[string]bool),
 	}
 	return &c
 }

 var _ soongconfig.SoongConfig = (*tracingConfig)(nil)

 // configModuleFactory takes an existing soongConfigModuleFactory and a
 // ModuleType to create a new ModuleFactory that uses a custom loadhook.
 func configModuleFactory(factory blueprint.ModuleFactory, moduleType *soongconfig.ModuleType) blueprint.ModuleFactory {
 	// Defer creation of conditional properties struct until the first call from the factory
 	// method. That avoids having to make a special call to the factory to create the properties
 	// structs from which the conditional properties struct is created. This is needed in order to
 	// allow singleton modules to be customized by soong_config_module_type as the
 	// SingletonModuleFactoryAdaptor factory registers a load hook for the singleton module
 	// everytime that it is called. Calling the factory twice causes a build failure as the load
 	// hook is called twice, the first time it updates the singleton module to indicate that it has
 	// been registered as a module, and the second time it fails because it thinks it has been
 	// registered again and a singleton module can only be registered once.
 	//
 	// This is an issue for singleton modules because:
 	// * Load hooks are registered on the module object and are only called when the module object
 	//   is created by Blueprint while processing the Android.bp file.
 	// * The module factory for a singleton module returns the same module object each time it is
 	//   called, and registers its load hook on that same module object.
 	// * When the module factory is called by Blueprint it then calls all the load hooks that have
 	//   been registered for every call to that module factory.
 	//
 	// It is not an issue for normal modules because they return a new module object each time the
 	// factory is called and so any load hooks registered on module objects which are discarded will
 	// not be run.
 	once := &sync.Once{}
 	conditionalFactoryProps := reflect.Value{}
 	getConditionalFactoryProps := func(props []interface{}) reflect.Value {
 		once.Do(func() {
 			conditionalFactoryProps = soongconfig.CreateProperties(props, moduleType)
 		})
 		return conditionalFactoryProps
 	}

 	return func() (blueprint.Module, []interface{}) {
 		module, props := factory()
 		conditionalFactoryProps := getConditionalFactoryProps(props)
 		if !conditionalFactoryProps.IsValid() {
 			return module, props
 		}

 		conditionalProps := proptools.CloneEmptyProperties(conditionalFactoryProps)
 		props = append(props, conditionalProps.Interface())

 		// Regular Soong operation wraps the existing module factory with a
 		// conditional on Soong config variables by reading the product
 		// config variables from Make.
 		AddLoadHook(module, func(ctx LoadHookContext) {
 			tracingConfig := newTracingConfig(ctx.Config().VendorConfig(moduleType.ConfigNamespace))
 			newProps, err := soongconfig.PropertiesToApply(moduleType, conditionalProps, tracingConfig)
 			if err != nil {
 				ctx.ModuleErrorf("%s", err)
 				return
 			}
 			for _, ps := range newProps {
 				ctx.AppendProperties(ps)
 			}

 			module.(Module).base().commonProperties.SoongConfigTrace = tracingConfig.getTrace()
 		})
 		return module, props
 	}
 }
	// Copyright 2019 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

	// This file provides module types that implement wrapper module types that add conditionals on
	// Soong config variables.

	import (
	"fmt"
	"path/filepath"
	"reflect"
	"strings"
	"sync"
	"text/scanner"

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

	"android/soong/android/soongconfig"
	)

	func init() {
	RegisterSoongConfigModuleBuildComponents(InitRegistrationContext)
	}

	func RegisterSoongConfigModuleBuildComponents(ctx RegistrationContext) {
	ctx.RegisterModuleType("soong_config_module_type_import", SoongConfigModuleTypeImportFactory)
	ctx.RegisterModuleType("soong_config_module_type", SoongConfigModuleTypeFactory)
	ctx.RegisterModuleType("soong_config_string_variable", SoongConfigStringVariableDummyFactory)
	ctx.RegisterModuleType("soong_config_bool_variable", SoongConfigBoolVariableDummyFactory)
	ctx.RegisterModuleType("soong_config_value_variable", SoongConfigValueVariableDummyFactory)
	}

	var PrepareForTestWithSoongConfigModuleBuildComponents = FixtureRegisterWithContext(RegisterSoongConfigModuleBuildComponents)

	type soongConfigModuleTypeImport struct {
	ModuleBase
	properties soongConfigModuleTypeImportProperties
	}

	type soongConfigModuleTypeImportProperties struct {
	From string
	Module_types []string
	}

	// soong_config_module_type_import imports module types with conditionals on Soong config
	// variables from another Android.bp file. The imported module type will exist for all
	// modules after the import in the Android.bp file.
	//
	// Each soong_config_variable supports an additional value `conditions_default`. The properties
	// specified in `conditions_default` will only be used under the following conditions:
	// bool variable: the variable is unspecified or not set to a true value
	// value variable: the variable is unspecified
	// list variable: the variable is unspecified
	// string variable: the variable is unspecified or the variable is set to a string unused in the
	// given module. For example, string variable `test` takes values: "a" and "b",
	// if the module contains a property `a` and `conditions_default`, when test=b,
	// the properties under `conditions_default` will be used. To specify that no
	// properties should be amended for `b`, you can set `b: {},`.
	//
	// For example, an Android.bp file could have:
	//
	// soong_config_module_type_import {
	// from: "device/acme/Android.bp",
	// module_types: ["acme_cc_defaults"],
	// }
	//
	// acme_cc_defaults {
	// name: "acme_defaults",
	// cflags: ["-DGENERIC"],
	// soong_config_variables: {
	// board: {
	// soc_a: {
	// cflags: ["-DSOC_A"],
	// },
	// soc_b: {
	// cflags: ["-DSOC_B"],
	// },
	// conditions_default: {
	// cflags: ["-DSOC_DEFAULT"],
	// },
	// },
	// feature: {
	// cflags: ["-DFEATURE"],
	// conditions_default: {
	// cflags: ["-DFEATURE_DEFAULT"],
	// },
	// },
	// width: {
	// cflags: ["-DWIDTH=%s"],
	// conditions_default: {
	// cflags: ["-DWIDTH=DEFAULT"],
	// },
	// },
	// impl: {
	// srcs: ["impl/%s"],
	// conditions_default: {
	// srcs: ["impl/default.cpp"],
	// },
	// },
	// },
	// }
	//
	// cc_library {
	// name: "libacme_foo",
	// defaults: ["acme_defaults"],
	// srcs: ["*.cpp"],
	// }
	//
	// And device/acme/Android.bp could have:
	//
	// soong_config_module_type {
	// name: "acme_cc_defaults",
	// module_type: "cc_defaults",
	// config_namespace: "acme",
	// variables: ["board"],
	// bool_variables: ["feature"],
	// value_variables: ["width"],
	// list_variables: ["impl"],
	// properties: ["cflags", "srcs"],
	// }
	//
	// soong_config_string_variable {
	// name: "board",
	// values: ["soc_a", "soc_b", "soc_c"],
	// }
	//
	// If an acme BoardConfig.mk file contained:
	// $(call add_sonng_config_namespace, acme)
	// $(call add_soong_config_var_value, acme, board, soc_a)
	// $(call add_soong_config_var_value, acme, feature, true)
	// $(call add_soong_config_var_value, acme, width, 200)
	// $(call add_soong_config_var_value, acme, impl, foo.cpp bar.cpp)
	//
	// Then libacme_foo would build with cflags "-DGENERIC -DSOC_A -DFEATURE -DWIDTH=200" and srcs
	// ["*.cpp", "impl/foo.cpp", "impl/bar.cpp"].
	//
	// Alternatively, if acme BoardConfig.mk file contained:
	//
	// SOONG_CONFIG_NAMESPACES += acme
	// SOONG_CONFIG_acme += \
	// board \
	// feature \
	//
	// SOONG_CONFIG_acme_feature := false
	//
	// Then libacme_foo would build with cflags:
	// "-DGENERIC -DSOC_DEFAULT -DFEATURE_DEFAULT -DSIZE=DEFAULT"
	// and with srcs:
	// ["*.cpp", "impl/default.cpp"].
	//
	// Similarly, if acme BoardConfig.mk file contained:
	//
	// SOONG_CONFIG_NAMESPACES += acme
	// SOONG_CONFIG_acme += \
	// board \
	// feature \
	//
	// SOONG_CONFIG_acme_board := soc_c
	// SOONG_CONFIG_acme_impl := foo.cpp bar.cpp
	//
	// Then libacme_foo would build with cflags:
	// "-DGENERIC -DSOC_DEFAULT -DFEATURE_DEFAULT -DSIZE=DEFAULT"
	// and with srcs:
	// ["*.cpp", "impl/foo.cpp", "impl/bar.cpp"].
	//

	func SoongConfigModuleTypeImportFactory() Module {
	module := &soongConfigModuleTypeImport{}

	module.AddProperties(&module.properties)
	AddLoadHook(module, func(ctx LoadHookContext) {
	importModuleTypes(ctx, module.properties.From, module.properties.Module_types...)
	})

	initAndroidModuleBase(module)
	return module
	}

	func (m *soongConfigModuleTypeImport) Name() string {
	// The generated name is non-deterministic, but it does not
	// matter because this module does not emit any rules.
	return soongconfig.CanonicalizeToProperty(m.properties.From) +
	"soong_config_module_type_import_" + fmt.Sprintf("%p", m)
	}

	func (*soongConfigModuleTypeImport) Namespaceless() {}
	func (*soongConfigModuleTypeImport) GenerateAndroidBuildActions(ModuleContext) {}

	// Create dummy modules for soong_config_module_type and soong_config_*_variable

	type soongConfigModuleTypeModule struct {
	ModuleBase
	properties soongconfig.ModuleTypeProperties
	}

	// soong_config_module_type defines module types with conditionals on Soong config
	// variables. The new module type will exist for all modules after the definition
	// in an Android.bp file, and can be imported into other Android.bp files using
	// soong_config_module_type_import.
	//
	// Each soong_config_variable supports an additional value `conditions_default`. The properties
	// specified in `conditions_default` will only be used under the following conditions:
	//
	// bool variable: the variable is unspecified or not set to a true value
	// value variable: the variable is unspecified
	// list variable: the variable is unspecified
	// string variable: the variable is unspecified or the variable is set to a string unused in the
	// given module. For example, string variable `test` takes values: "a" and "b",
	// if the module contains a property `a` and `conditions_default`, when test=b,
	// the properties under `conditions_default` will be used. To specify that no
	// properties should be amended for `b`, you can set `b: {},`.
	//
	// For example, an Android.bp file could have:
	//
	// soong_config_module_type {
	// name: "acme_cc_defaults",
	// module_type: "cc_defaults",
	// config_namespace: "acme",
	// variables: ["board"],
	// bool_variables: ["feature"],
	// value_variables: ["width"],
	// list_variables: ["impl"],
	// properties: ["cflags", "srcs"],
	// }
	//
	// soong_config_string_variable {
	// name: "board",
	// values: ["soc_a", "soc_b"],
	// }
	//
	// acme_cc_defaults {
	// name: "acme_defaults",
	// cflags: ["-DGENERIC"],
	// soong_config_variables: {
	// board: {
	// soc_a: {
	// cflags: ["-DSOC_A"],
	// },
	// soc_b: {
	// cflags: ["-DSOC_B"],
	// },
	// conditions_default: {
	// cflags: ["-DSOC_DEFAULT"],
	// },
	// },
	// feature: {
	// cflags: ["-DFEATURE"],
	// conditions_default: {
	// cflags: ["-DFEATURE_DEFAULT"],
	// },
	// },
	// width: {
	// cflags: ["-DWIDTH=%s"],
	// conditions_default: {
	// cflags: ["-DWIDTH=DEFAULT"],
	// },
	// },
	// impl: {
	// srcs: ["impl/%s"],
	// conditions_default: {
	// srcs: ["impl/default.cpp"],
	// },
	// },
	// },
	// }
	//
	// cc_library {
	// name: "libacme_foo",
	// defaults: ["acme_defaults"],
	// srcs: ["*.cpp"],
	// }
	//
	// If an acme BoardConfig.mk file contained:
	//
	// SOONG_CONFIG_NAMESPACES += acme
	// SOONG_CONFIG_acme += \
	// board \
	// feature \
	//
	// SOONG_CONFIG_acme_board := soc_a
	// SOONG_CONFIG_acme_feature := true
	// SOONG_CONFIG_acme_width := 200
	// SOONG_CONFIG_acme_impl := foo.cpp bar.cpp
	//
	// Then libacme_foo would build with cflags "-DGENERIC -DSOC_A -DFEATURE" and srcs
	// ["*.cpp", "impl/foo.cpp", "impl/bar.cpp"].
	func SoongConfigModuleTypeFactory() Module {
	module := &soongConfigModuleTypeModule{}

	module.AddProperties(&module.properties)

	AddLoadHook(module, func(ctx LoadHookContext) {
	// A soong_config_module_type module should implicitly import itself.
	importModuleTypes(ctx, ctx.BlueprintsFile(), module.properties.Name)
	})

	initAndroidModuleBase(module)

	return module
	}

	func (m *soongConfigModuleTypeModule) Name() string {
	return m.properties.Name + fmt.Sprintf("%p", m)
	}
	func (*soongConfigModuleTypeModule) Namespaceless() {}
	func (*soongConfigModuleTypeModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

	type soongConfigStringVariableDummyModule struct {
	ModuleBase
	properties soongconfig.VariableProperties
	stringProperties soongconfig.StringVariableProperties
	}

	type soongConfigBoolVariableDummyModule struct {
	ModuleBase
	properties soongconfig.VariableProperties
	}

	type soongConfigValueVariableDummyModule struct {
	ModuleBase
	properties soongconfig.VariableProperties
	}

	// soong_config_string_variable defines a variable and a set of possible string values for use
	// in a soong_config_module_type definition.
	func SoongConfigStringVariableDummyFactory() Module {
	module := &soongConfigStringVariableDummyModule{}
	module.AddProperties(&module.properties, &module.stringProperties)
	initAndroidModuleBase(module)
	return module
	}

	// soong_config_string_variable defines a variable with true or false values for use
	// in a soong_config_module_type definition.
	func SoongConfigBoolVariableDummyFactory() Module {
	module := &soongConfigBoolVariableDummyModule{}
	module.AddProperties(&module.properties)
	initAndroidModuleBase(module)
	return module
	}

	// soong_config_value_variable defines a variable whose value can be expanded into
	// the value of a string property.
	func SoongConfigValueVariableDummyFactory() Module {
	module := &soongConfigValueVariableDummyModule{}
	module.AddProperties(&module.properties)
	initAndroidModuleBase(module)
	return module
	}

	func (m *soongConfigStringVariableDummyModule) Name() string {
	return m.properties.Name + fmt.Sprintf("%p", m)
	}
	func (*soongConfigStringVariableDummyModule) Namespaceless() {}
	func (*soongConfigStringVariableDummyModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

	func (m *soongConfigBoolVariableDummyModule) Name() string {
	return m.properties.Name + fmt.Sprintf("%p", m)
	}
	func (*soongConfigBoolVariableDummyModule) Namespaceless() {}
	func (*soongConfigBoolVariableDummyModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

	func (m *soongConfigValueVariableDummyModule) Name() string {
	return m.properties.Name + fmt.Sprintf("%p", m)
	}
	func (*soongConfigValueVariableDummyModule) Namespaceless() {}
	func (*soongConfigValueVariableDummyModule) GenerateAndroidBuildActions(ctx ModuleContext) {}

	// importModuleTypes registers the module factories for a list of module types defined
	// in an Android.bp file. These module factories are scoped for the current Android.bp
	// file only.
	func importModuleTypes(ctx LoadHookContext, from string, moduleTypes ...string) {
	from = filepath.Clean(from)
	if filepath.Ext(from) != ".bp" {
	ctx.PropertyErrorf("from", "%q must be a file with extension .bp", from)
	return
	}

	if strings.HasPrefix(from, "../") {
	ctx.PropertyErrorf("from", "%q must not use ../ to escape the source tree",
	from)
	return
	}

	moduleTypeDefinitions := loadSoongConfigModuleTypeDefinition(ctx, from)
	if moduleTypeDefinitions == nil {
	return
	}
	for _, moduleType := range moduleTypes {
	if factory, ok := moduleTypeDefinitions[moduleType]; ok {
	ctx.registerScopedModuleType(moduleType, factory)
	} else {
	ctx.PropertyErrorf("module_types", "module type %q not defined in %q",
	moduleType, from)
	}
	}
	}

	// loadSoongConfigModuleTypeDefinition loads module types from an Android.bp file. It caches the
	// result so each file is only parsed once.
	func loadSoongConfigModuleTypeDefinition(ctx LoadHookContext, from string) map[string]blueprint.ModuleFactory {
	type onceKeyType string
	key := NewCustomOnceKey(onceKeyType(filepath.Clean(from)))

	reportErrors := func(ctx LoadHookContext, filename string, errs ...error) {
	for _, err := range errs {
	if parseErr, ok := err.(*parser.ParseError); ok {
	ctx.Errorf(parseErr.Pos, "%s", parseErr.Err)
	} else {
	ctx.Errorf(scanner.Position{Filename: filename}, "%s", err)
	}
	}
	}

	return ctx.Config().Once(key, func() interface{} {
	ctx.AddNinjaFileDeps(from)
	r, err := ctx.Config().fs.Open(from)
	if err != nil {
	ctx.PropertyErrorf("from", "failed to open %q: %s", from, err)
	return (map[string]blueprint.ModuleFactory)(nil)
	}
	defer r.Close()

	mtDef, errs := soongconfig.Parse(r, from)
	if len(errs) > 0 {
	reportErrors(ctx, from, errs...)
	return (map[string]blueprint.ModuleFactory)(nil)
	}

	globalModuleTypes := ctx.moduleFactories()

	factories := make(map[string]blueprint.ModuleFactory)

	for name, moduleType := range mtDef.ModuleTypes {
	factory := globalModuleTypes[moduleType.BaseModuleType]
	if factory != nil {
	factories[name] = configModuleFactory(factory, moduleType)
	} else {
	reportErrors(ctx, from,
	fmt.Errorf("missing global module type factory for %q", moduleType.BaseModuleType))
	}
	}

	if ctx.Failed() {
	return (map[string]blueprint.ModuleFactory)(nil)
	}

	return factories
	}).(map[string]blueprint.ModuleFactory)
	}

	// tracingConfig is a wrapper to soongconfig.SoongConfig which records all accesses to SoongConfig.
	type tracingConfig struct {
	config soongconfig.SoongConfig
	boolSet map[string]bool
	stringSet map[string]string
	isSetSet map[string]bool
	}

	func (c *tracingConfig) Bool(name string) bool {
	c.boolSet[name] = c.config.Bool(name)
	return c.boolSet[name]
	}

	func (c *tracingConfig) String(name string) string {
	c.stringSet[name] = c.config.String(name)
	return c.stringSet[name]
	}

	func (c *tracingConfig) IsSet(name string) bool {
	c.isSetSet[name] = c.config.IsSet(name)
	return c.isSetSet[name]
	}

	func (c *tracingConfig) getTrace() soongConfigTrace {
	ret := soongConfigTrace{}

	for k, v := range c.boolSet {
	ret.Bools = append(ret.Bools, fmt.Sprintf("%q:%t", k, v))
	}
	for k, v := range c.stringSet {
	ret.Strings = append(ret.Strings, fmt.Sprintf("%q:%q", k, v))
	}
	for k, v := range c.isSetSet {
	ret.IsSets = append(ret.IsSets, fmt.Sprintf("%q:%t", k, v))
	}

	return ret
	}

	func newTracingConfig(config soongconfig.SoongConfig) *tracingConfig {
	c := tracingConfig{
	config: config,
	boolSet: make(map[string]bool),
	stringSet: make(map[string]string),
	isSetSet: make(map[string]bool),
	}
	return &c
	}

	var _ soongconfig.SoongConfig = (*tracingConfig)(nil)

	// configModuleFactory takes an existing soongConfigModuleFactory and a
	// ModuleType to create a new ModuleFactory that uses a custom loadhook.
	func configModuleFactory(factory blueprint.ModuleFactory, moduleType *soongconfig.ModuleType) blueprint.ModuleFactory {
	// Defer creation of conditional properties struct until the first call from the factory
	// method. That avoids having to make a special call to the factory to create the properties
	// structs from which the conditional properties struct is created. This is needed in order to
	// allow singleton modules to be customized by soong_config_module_type as the
	// SingletonModuleFactoryAdaptor factory registers a load hook for the singleton module
	// everytime that it is called. Calling the factory twice causes a build failure as the load
	// hook is called twice, the first time it updates the singleton module to indicate that it has
	// been registered as a module, and the second time it fails because it thinks it has been
	// registered again and a singleton module can only be registered once.
	//
	// This is an issue for singleton modules because:
	// * Load hooks are registered on the module object and are only called when the module object
	// is created by Blueprint while processing the Android.bp file.
	// * The module factory for a singleton module returns the same module object each time it is
	// called, and registers its load hook on that same module object.
	// * When the module factory is called by Blueprint it then calls all the load hooks that have
	// been registered for every call to that module factory.
	//
	// It is not an issue for normal modules because they return a new module object each time the
	// factory is called and so any load hooks registered on module objects which are discarded will
	// not be run.
	once := &sync.Once{}
	conditionalFactoryProps := reflect.Value{}
	getConditionalFactoryProps := func(props []interface{}) reflect.Value {
	once.Do(func() {
	conditionalFactoryProps = soongconfig.CreateProperties(props, moduleType)
	})
	return conditionalFactoryProps
	}

	return func() (blueprint.Module, []interface{}) {
	module, props := factory()
	conditionalFactoryProps := getConditionalFactoryProps(props)
	if !conditionalFactoryProps.IsValid() {
	return module, props
	}

	conditionalProps := proptools.CloneEmptyProperties(conditionalFactoryProps)
	props = append(props, conditionalProps.Interface())

	// Regular Soong operation wraps the existing module factory with a
	// conditional on Soong config variables by reading the product
	// config variables from Make.
	AddLoadHook(module, func(ctx LoadHookContext) {
	tracingConfig := newTracingConfig(ctx.Config().VendorConfig(moduleType.ConfigNamespace))
	newProps, err := soongconfig.PropertiesToApply(moduleType, conditionalProps, tracingConfig)
	if err != nil {
	ctx.ModuleErrorf("%s", err)
	return
	}
	for _, ps := range newProps {
	ctx.AppendProperties(ps)
	}

	module.(Module).base().commonProperties.SoongConfigTrace = tracingConfig.getTrace()
	})
	return module, props
	}
	}