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// 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
}