rust/project_json.go - platform/build/soong - Git at Google

 // Copyright 2020 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 rust

 import (
 	"encoding/json"
 	"fmt"
 	"path"

 	"android/soong/android"
 )

 // This singleton collects Rust crate definitions and generates a JSON file
 // (${OUT_DIR}/soong/rust-project.json) which can be use by external tools,
 // such as rust-analyzer. It does so when either make, mm, mma, mmm or mmma is
 // called.  This singleton is enabled only if SOONG_GEN_RUST_PROJECT is set.
 // For example,
 //
 //   $ SOONG_GEN_RUST_PROJECT=1 m nothing

 const (
 	// Environment variables used to control the behavior of this singleton.
 	envVariableCollectRustDeps = "SOONG_GEN_RUST_PROJECT"
 	rustProjectJsonFileName    = "rust-project.json"
 )

 // The format of rust-project.json is not yet finalized. A current description is available at:
 // https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/manual.adoc#non-cargo-based-projects
 type rustProjectDep struct {
 	// The Crate attribute is the index of the dependency in the Crates array in rustProjectJson.
 	Crate int    `json:"crate"`
 	Name  string `json:"name"`
 }

 type rustProjectCrate struct {
 	DisplayName string            `json:"display_name"`
 	RootModule  string            `json:"root_module"`
 	Edition     string            `json:"edition,omitempty"`
 	Deps        []rustProjectDep  `json:"deps"`
 	Cfg         []string          `json:"cfg"`
 	Env         map[string]string `json:"env"`
 	ProcMacro   bool              `json:"is_proc_macro"`
 }

 type rustProjectJson struct {
 	Crates []rustProjectCrate `json:"crates"`
 }

 // crateInfo is used during the processing to keep track of the known crates.
 type crateInfo struct {
 	Idx  int            // Index of the crate in rustProjectJson.Crates slice.
 	Deps map[string]int // The keys are the module names and not the crate names.
 }

 type projectGeneratorSingleton struct {
 	project     rustProjectJson
 	knownCrates map[string]crateInfo // Keys are module names.
 }

 func rustProjectGeneratorSingleton() android.Singleton {
 	return &projectGeneratorSingleton{}
 }

 func init() {
 	android.RegisterSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
 }

 // sourceProviderVariantSource returns the path to the source file if this
 // module variant should be used as a priority.
 //
 // SourceProvider modules may have multiple variants considered as source
 // (e.g., x86_64 and armv8). For a module available on device, use the source
 // generated for the target. For a host-only module, use the source generated
 // for the host.
 func sourceProviderVariantSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
 	rustLib, ok := rModule.compiler.(*libraryDecorator)
 	if !ok {
 		return "", false
 	}
 	if rustLib.source() {
 		switch rModule.hod {
 		case android.HostSupported, android.HostSupportedNoCross:
 			if rModule.Target().String() == ctx.Config().BuildOSTarget.String() {
 				src := rustLib.sourceProvider.Srcs()[0]
 				return src.String(), true
 			}
 		default:
 			if rModule.Target().String() == ctx.Config().AndroidFirstDeviceTarget.String() {
 				src := rustLib.sourceProvider.Srcs()[0]
 				return src.String(), true
 			}
 		}
 	}
 	return "", false
 }

 // sourceProviderSource finds the main source file of a source-provider crate.
 func sourceProviderSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
 	rustLib, ok := rModule.compiler.(*libraryDecorator)
 	if !ok {
 		return "", false
 	}
 	if rustLib.source() {
 		// This is a source-variant, check if we are the right variant
 		// depending on the module configuration.
 		if src, ok := sourceProviderVariantSource(ctx, rModule); ok {
 			return src, true
 		}
 	}
 	foundSource := false
 	sourceSrc := ""
 	// Find the variant with the source and return its.
 	ctx.VisitAllModuleVariants(rModule, func(variant android.Module) {
 		if foundSource {
 			return
 		}
 		// All variants of a source provider library are libraries.
 		rVariant, _ := variant.(*Module)
 		variantLib, _ := rVariant.compiler.(*libraryDecorator)
 		if variantLib.source() {
 			sourceSrc, ok = sourceProviderVariantSource(ctx, rVariant)
 			if ok {
 				foundSource = true
 			}
 		}
 	})
 	if !foundSource {
 		ctx.Errorf("No valid source for source provider found: %v\n", rModule)
 	}
 	return sourceSrc, foundSource
 }

 // crateSource finds the main source file (.rs) for a crate.
 func crateSource(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (string, bool) {
 	// Basic libraries, executables and tests.
 	srcs := comp.Properties.Srcs
 	if len(srcs) != 0 {
 		return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
 	}
 	// SourceProvider libraries.
 	if rModule.sourceProvider != nil {
 		return sourceProviderSource(ctx, rModule)
 	}
 	return "", false
 }

 // mergeDependencies visits all the dependencies for module and updates crate and deps
 // with any new dependency.
 func (singleton *projectGeneratorSingleton) mergeDependencies(ctx android.SingletonContext,
 	module *Module, crate *rustProjectCrate, deps map[string]int) {

 	ctx.VisitDirectDeps(module, func(child android.Module) {
 		// Skip intra-module dependencies (i.e., generated-source library depending on the source variant).
 		if module.Name() == child.Name() {
 			return
 		}
 		// Skip unsupported modules.
 		rChild, compChild, ok := isModuleSupported(ctx, child)
 		if !ok {
 			return
 		}
 		// For unknown dependency, add it first.
 		var childId int
 		cInfo, known := singleton.knownCrates[rChild.Name()]
 		if !known {
 			childId, ok = singleton.addCrate(ctx, rChild, compChild)
 			if !ok {
 				return
 			}
 		} else {
 			childId = cInfo.Idx
 		}
 		// Is this dependency known already?
 		if _, ok = deps[child.Name()]; ok {
 			return
 		}
 		crate.Deps = append(crate.Deps, rustProjectDep{Crate: childId, Name: rChild.CrateName()})
 		deps[child.Name()] = childId
 	})
 }

 // isModuleSupported returns the RustModule and baseCompiler if the module
 // should be considered for inclusion in rust-project.json.
 func isModuleSupported(ctx android.SingletonContext, module android.Module) (*Module, *baseCompiler, bool) {
 	rModule, ok := module.(*Module)
 	if !ok {
 		return nil, nil, false
 	}
 	if rModule.compiler == nil {
 		return nil, nil, false
 	}
 	var comp *baseCompiler
 	switch c := rModule.compiler.(type) {
 	case *libraryDecorator:
 		comp = c.baseCompiler
 	case *binaryDecorator:
 		comp = c.baseCompiler
 	case *testDecorator:
 		comp = c.binaryDecorator.baseCompiler
 	case *procMacroDecorator:
 		comp = c.baseCompiler
 	case *toolchainLibraryDecorator:
 		comp = c.baseCompiler
 	default:
 		return nil, nil, false
 	}
 	return rModule, comp, true
 }

 // addCrate adds a crate to singleton.project.Crates ensuring that required
 // dependencies are also added. It returns the index of the new crate in
 // singleton.project.Crates
 func (singleton *projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (int, bool) {
 	rootModule, ok := crateSource(ctx, rModule, comp)
 	if !ok {
 		ctx.Errorf("Unable to find source for valid module: %v", rModule)
 		return 0, false
 	}

 	_, procMacro := rModule.compiler.(*procMacroDecorator)

 	crate := rustProjectCrate{
 		DisplayName: rModule.Name(),
 		RootModule:  rootModule,
 		Edition:     comp.edition(),
 		Deps:        make([]rustProjectDep, 0),
 		Cfg:         make([]string, 0),
 		Env:         make(map[string]string),
 		ProcMacro:   procMacro,
 	}

 	if comp.CargoOutDir().Valid() {
 		crate.Env["OUT_DIR"] = comp.CargoOutDir().String()
 	}

 	for _, feature := range comp.Properties.Features {
 		crate.Cfg = append(crate.Cfg, "feature=\""+feature+"\"")
 	}

 	deps := make(map[string]int)
 	singleton.mergeDependencies(ctx, rModule, &crate, deps)

 	idx := len(singleton.project.Crates)
 	singleton.knownCrates[rModule.Name()] = crateInfo{Idx: idx, Deps: deps}
 	singleton.project.Crates = append(singleton.project.Crates, crate)
 	return idx, true
 }

 // appendCrateAndDependencies creates a rustProjectCrate for the module argument and appends it to singleton.project.
 // It visits the dependencies of the module depth-first so the dependency ID can be added to the current module. If the
 // current module is already in singleton.knownCrates, its dependencies are merged.
 func (singleton *projectGeneratorSingleton) appendCrateAndDependencies(ctx android.SingletonContext, module android.Module) {
 	rModule, comp, ok := isModuleSupported(ctx, module)
 	if !ok {
 		return
 	}
 	// If we have seen this crate already; merge any new dependencies.
 	if cInfo, ok := singleton.knownCrates[module.Name()]; ok {
 		crate := singleton.project.Crates[cInfo.Idx]
 		singleton.mergeDependencies(ctx, rModule, &crate, cInfo.Deps)
 		singleton.project.Crates[cInfo.Idx] = crate
 		return
 	}
 	singleton.addCrate(ctx, rModule, comp)
 }

 func (singleton *projectGeneratorSingleton) GenerateBuildActions(ctx android.SingletonContext) {
 	if !ctx.Config().IsEnvTrue(envVariableCollectRustDeps) {
 		return
 	}

 	singleton.knownCrates = make(map[string]crateInfo)
 	ctx.VisitAllModules(func(module android.Module) {
 		singleton.appendCrateAndDependencies(ctx, module)
 	})

 	path := android.PathForOutput(ctx, rustProjectJsonFileName)
 	err := createJsonFile(singleton.project, path)
 	if err != nil {
 		ctx.Errorf(err.Error())
 	}
 }

 func createJsonFile(project rustProjectJson, rustProjectPath android.WritablePath) error {
 	buf, err := json.MarshalIndent(project, "", "  ")
 	if err != nil {
 		return fmt.Errorf("JSON marshal of rustProjectJson failed: %s", err)
 	}
 	err = android.WriteFileToOutputDir(rustProjectPath, buf, 0666)
 	if err != nil {
 		return fmt.Errorf("Writing rust-project to %s failed: %s", rustProjectPath.String(), err)
 	}
 	return nil
 }
	// Copyright 2020 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 rust

	import (
	"encoding/json"
	"fmt"
	"path"

	"android/soong/android"
	)

	// This singleton collects Rust crate definitions and generates a JSON file
	// (${OUT_DIR}/soong/rust-project.json) which can be use by external tools,
	// such as rust-analyzer. It does so when either make, mm, mma, mmm or mmma is
	// called. This singleton is enabled only if SOONG_GEN_RUST_PROJECT is set.
	// For example,
	//
	// $ SOONG_GEN_RUST_PROJECT=1 m nothing

	const (
	// Environment variables used to control the behavior of this singleton.
	envVariableCollectRustDeps = "SOONG_GEN_RUST_PROJECT"
	rustProjectJsonFileName = "rust-project.json"
	)

	// The format of rust-project.json is not yet finalized. A current description is available at:
	// https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/manual.adoc#non-cargo-based-projects
	type rustProjectDep struct {
	// The Crate attribute is the index of the dependency in the Crates array in rustProjectJson.
	Crate int `json:"crate"`
	Name string `json:"name"`
	}

	type rustProjectCrate struct {
	DisplayName string `json:"display_name"`
	RootModule string `json:"root_module"`
	Edition string `json:"edition,omitempty"`
	Deps []rustProjectDep `json:"deps"`
	Cfg []string `json:"cfg"`
	Env map[string]string `json:"env"`
	ProcMacro bool `json:"is_proc_macro"`
	}

	type rustProjectJson struct {
	Crates []rustProjectCrate `json:"crates"`
	}

	// crateInfo is used during the processing to keep track of the known crates.
	type crateInfo struct {
	Idx int // Index of the crate in rustProjectJson.Crates slice.
	Deps map[string]int // The keys are the module names and not the crate names.
	}

	type projectGeneratorSingleton struct {
	project rustProjectJson
	knownCrates map[string]crateInfo // Keys are module names.
	}

	func rustProjectGeneratorSingleton() android.Singleton {
	return &projectGeneratorSingleton{}
	}

	func init() {
	android.RegisterSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
	}

	// sourceProviderVariantSource returns the path to the source file if this
	// module variant should be used as a priority.
	//
	// SourceProvider modules may have multiple variants considered as source
	// (e.g., x86_64 and armv8). For a module available on device, use the source
	// generated for the target. For a host-only module, use the source generated
	// for the host.
	func sourceProviderVariantSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
	rustLib, ok := rModule.compiler.(*libraryDecorator)
	if !ok {
	return "", false
	}
	if rustLib.source() {
	switch rModule.hod {
	case android.HostSupported, android.HostSupportedNoCross:
	if rModule.Target().String() == ctx.Config().BuildOSTarget.String() {
	src := rustLib.sourceProvider.Srcs()[0]
	return src.String(), true
	}
	default:
	if rModule.Target().String() == ctx.Config().AndroidFirstDeviceTarget.String() {
	src := rustLib.sourceProvider.Srcs()[0]
	return src.String(), true
	}
	}
	}
	return "", false
	}

	// sourceProviderSource finds the main source file of a source-provider crate.
	func sourceProviderSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
	rustLib, ok := rModule.compiler.(*libraryDecorator)
	if !ok {
	return "", false
	}
	if rustLib.source() {
	// This is a source-variant, check if we are the right variant
	// depending on the module configuration.
	if src, ok := sourceProviderVariantSource(ctx, rModule); ok {
	return src, true
	}
	}
	foundSource := false
	sourceSrc := ""
	// Find the variant with the source and return its.
	ctx.VisitAllModuleVariants(rModule, func(variant android.Module) {
	if foundSource {
	return
	}
	// All variants of a source provider library are libraries.
	rVariant, _ := variant.(*Module)
	variantLib, _ := rVariant.compiler.(*libraryDecorator)
	if variantLib.source() {
	sourceSrc, ok = sourceProviderVariantSource(ctx, rVariant)
	if ok {
	foundSource = true
	}
	}
	})
	if !foundSource {
	ctx.Errorf("No valid source for source provider found: %v\n", rModule)
	}
	return sourceSrc, foundSource
	}

	// crateSource finds the main source file (.rs) for a crate.
	func crateSource(ctx android.SingletonContext, rModule Module, comp baseCompiler) (string, bool) {
	// Basic libraries, executables and tests.
	srcs := comp.Properties.Srcs
	if len(srcs) != 0 {
	return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
	}
	// SourceProvider libraries.
	if rModule.sourceProvider != nil {
	return sourceProviderSource(ctx, rModule)
	}
	return "", false
	}

	// mergeDependencies visits all the dependencies for module and updates crate and deps
	// with any new dependency.
	func (singleton *projectGeneratorSingleton) mergeDependencies(ctx android.SingletonContext,
	module Module, crate rustProjectCrate, deps map[string]int) {

	ctx.VisitDirectDeps(module, func(child android.Module) {
	// Skip intra-module dependencies (i.e., generated-source library depending on the source variant).
	if module.Name() == child.Name() {
	return
	}
	// Skip unsupported modules.
	rChild, compChild, ok := isModuleSupported(ctx, child)
	if !ok {
	return
	}
	// For unknown dependency, add it first.
	var childId int
	cInfo, known := singleton.knownCrates[rChild.Name()]
	if !known {
	childId, ok = singleton.addCrate(ctx, rChild, compChild)
	if !ok {
	return
	}
	} else {
	childId = cInfo.Idx
	}
	// Is this dependency known already?
	if _, ok = deps[child.Name()]; ok {
	return
	}
	crate.Deps = append(crate.Deps, rustProjectDep{Crate: childId, Name: rChild.CrateName()})
	deps[child.Name()] = childId
	})
	}

	// isModuleSupported returns the RustModule and baseCompiler if the module
	// should be considered for inclusion in rust-project.json.
	func isModuleSupported(ctx android.SingletonContext, module android.Module) (Module, baseCompiler, bool) {
	rModule, ok := module.(*Module)
	if !ok {
	return nil, nil, false
	}
	if rModule.compiler == nil {
	return nil, nil, false
	}
	var comp *baseCompiler
	switch c := rModule.compiler.(type) {
	case *libraryDecorator:
	comp = c.baseCompiler
	case *binaryDecorator:
	comp = c.baseCompiler
	case *testDecorator:
	comp = c.binaryDecorator.baseCompiler
	case *procMacroDecorator:
	comp = c.baseCompiler
	case *toolchainLibraryDecorator:
	comp = c.baseCompiler
	default:
	return nil, nil, false
	}
	return rModule, comp, true
	}

	// addCrate adds a crate to singleton.project.Crates ensuring that required
	// dependencies are also added. It returns the index of the new crate in
	// singleton.project.Crates
	func (singleton projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule Module, comp *baseCompiler) (int, bool) {
	rootModule, ok := crateSource(ctx, rModule, comp)
	if !ok {
	ctx.Errorf("Unable to find source for valid module: %v", rModule)
	return 0, false
	}

	_, procMacro := rModule.compiler.(*procMacroDecorator)

	crate := rustProjectCrate{
	DisplayName: rModule.Name(),
	RootModule: rootModule,
	Edition: comp.edition(),
	Deps: make([]rustProjectDep, 0),
	Cfg: make([]string, 0),
	Env: make(map[string]string),
	ProcMacro: procMacro,
	}

	if comp.CargoOutDir().Valid() {
	crate.Env["OUT_DIR"] = comp.CargoOutDir().String()
	}

	for _, feature := range comp.Properties.Features {
	crate.Cfg = append(crate.Cfg, "feature=\""+feature+"\"")
	}

	deps := make(map[string]int)
	singleton.mergeDependencies(ctx, rModule, &crate, deps)

	idx := len(singleton.project.Crates)
	singleton.knownCrates[rModule.Name()] = crateInfo{Idx: idx, Deps: deps}
	singleton.project.Crates = append(singleton.project.Crates, crate)
	return idx, true
	}

	// appendCrateAndDependencies creates a rustProjectCrate for the module argument and appends it to singleton.project.
	// It visits the dependencies of the module depth-first so the dependency ID can be added to the current module. If the
	// current module is already in singleton.knownCrates, its dependencies are merged.
	func (singleton *projectGeneratorSingleton) appendCrateAndDependencies(ctx android.SingletonContext, module android.Module) {
	rModule, comp, ok := isModuleSupported(ctx, module)
	if !ok {
	return
	}
	// If we have seen this crate already; merge any new dependencies.
	if cInfo, ok := singleton.knownCrates[module.Name()]; ok {
	crate := singleton.project.Crates[cInfo.Idx]
	singleton.mergeDependencies(ctx, rModule, &crate, cInfo.Deps)
	singleton.project.Crates[cInfo.Idx] = crate
	return
	}
	singleton.addCrate(ctx, rModule, comp)
	}

	func (singleton *projectGeneratorSingleton) GenerateBuildActions(ctx android.SingletonContext) {
	if !ctx.Config().IsEnvTrue(envVariableCollectRustDeps) {
	return
	}

	singleton.knownCrates = make(map[string]crateInfo)
	ctx.VisitAllModules(func(module android.Module) {
	singleton.appendCrateAndDependencies(ctx, module)
	})

	path := android.PathForOutput(ctx, rustProjectJsonFileName)
	err := createJsonFile(singleton.project, path)
	if err != nil {
	ctx.Errorf(err.Error())
	}
	}

	func createJsonFile(project rustProjectJson, rustProjectPath android.WritablePath) error {
	buf, err := json.MarshalIndent(project, "", " ")
	if err != nil {
	return fmt.Errorf("JSON marshal of rustProjectJson failed: %s", err)
	}
	err = android.WriteFileToOutputDir(rustProjectPath, buf, 0666)
	if err != nil {
	return fmt.Errorf("Writing rust-project to %s failed: %s", rustProjectPath.String(), err)
	}
	return nil
	}