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

 // Copyright 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 rust

 import (
 	"fmt"
 	"path/filepath"

 	"github.com/google/blueprint/proptools"

 	"android/soong/android"
 	"android/soong/rust/config"
 )

 type RustLinkage int

 const (
 	DefaultLinkage RustLinkage = iota
 	RlibLinkage
 	DylibLinkage
 )

 func (compiler *baseCompiler) edition() string {
 	return proptools.StringDefault(compiler.Properties.Edition, config.DefaultEdition)
 }

 func (compiler *baseCompiler) setNoStdlibs() {
 	compiler.Properties.No_stdlibs = proptools.BoolPtr(true)
 }

 func (compiler *baseCompiler) disableLints() {
 	compiler.Properties.Lints = proptools.StringPtr("none")
 }

 func NewBaseCompiler(dir, dir64 string, location installLocation) *baseCompiler {
 	return &baseCompiler{
 		Properties: BaseCompilerProperties{},
 		dir:        dir,
 		dir64:      dir64,
 		location:   location,
 	}
 }

 type installLocation int

 const (
 	InstallInSystem installLocation = 0
 	InstallInData                   = iota

 	incorrectSourcesError = "srcs can only contain one path for a rust file and source providers prefixed by \":\""
 	genSubDir             = "out/"
 )

 type BaseCompilerProperties struct {
 	// path to the source file that is the main entry point of the program (e.g. main.rs or lib.rs)
 	Srcs []string `android:"path,arch_variant"`

 	// name of the lint set that should be used to validate this module.
 	//
 	// Possible values are "default" (for using a sensible set of lints
 	// depending on the module's location), "android" (for the strictest
 	// lint set that applies to all Android platform code), "vendor" (for
 	// a relaxed set) and "none" (for ignoring all lint warnings and
 	// errors). The default value is "default".
 	Lints *string

 	// flags to pass to rustc. To enable configuration options or features, use the "cfgs" or "features" properties.
 	Flags []string `android:"arch_variant"`

 	// flags to pass to the linker
 	Ld_flags []string `android:"arch_variant"`

 	// list of rust rlib crate dependencies
 	Rlibs []string `android:"arch_variant"`

 	// list of rust dylib crate dependencies
 	Dylibs []string `android:"arch_variant"`

 	// list of rust automatic crate dependencies
 	Rustlibs []string `android:"arch_variant"`

 	// list of rust proc_macro crate dependencies
 	Proc_macros []string `android:"arch_variant"`

 	// list of C shared library dependencies
 	Shared_libs []string `android:"arch_variant"`

 	// list of C static library dependencies. These dependencies do not normally propagate to dependents
 	// and may need to be redeclared. See whole_static_libs for bundling static dependencies into a library.
 	Static_libs []string `android:"arch_variant"`

 	// Similar to static_libs, but will bundle the static library dependency into a library. This is helpful
 	// to avoid having to redeclare the dependency for dependents of this library, but in some cases may also
 	// result in bloat if multiple dependencies all include the same static library whole.
 	//
 	// The common use case for this is when the static library is unlikely to be a dependency of other modules to avoid
 	// having to redeclare the static library dependency for every dependent module.
 	// If you are not sure what to, for rust_library modules most static dependencies should go in static_libraries,
 	// and for rust_ffi modules most static dependencies should go into whole_static_libraries.
 	//
 	// For rust_ffi static variants, these libraries will be included in the resulting static library archive.
 	//
 	// For rust_library rlib variants, these libraries will be bundled into the resulting rlib library. This will
 	// include all of the static libraries symbols in any dylibs or binaries which use this rlib as well.
 	Whole_static_libs []string `android:"arch_variant"`

 	// crate name, required for modules which produce Rust libraries: rust_library, rust_ffi and SourceProvider
 	// modules which create library variants (rust_bindgen). This must be the expected extern crate name used in
 	// source, and is required to conform to an enforced format matching library output files (if the output file is
 	// lib<someName><suffix>, the crate_name property must be <someName>).
 	Crate_name string `android:"arch_variant"`

 	// list of features to enable for this crate
 	Features []string `android:"arch_variant"`

 	// list of configuration options to enable for this crate. To enable features, use the "features" property.
 	Cfgs []string `android:"arch_variant"`

 	// specific rust edition that should be used if the default version is not desired
 	Edition *string `android:"arch_variant"`

 	// sets name of the output
 	Stem *string `android:"arch_variant"`

 	// append to name of output
 	Suffix *string `android:"arch_variant"`

 	// install to a subdirectory of the default install path for the module
 	Relative_install_path *string `android:"arch_variant"`

 	// whether to suppress inclusion of standard crates - defaults to false
 	No_stdlibs *bool

 	// Change the rustlibs linkage to select rlib linkage by default for device targets.
 	// Also link libstd as an rlib as well on device targets.
 	// Note: This is the default behavior for host targets.
 	//
 	// This is primarily meant for rust_binary and rust_ffi modules where the default
 	// linkage of libstd might need to be overridden in some use cases. This should
 	// generally be avoided with other module types since it may cause collisions at
 	// linkage if all dependencies of the root binary module do not link against libstd\
 	// the same way.
 	Prefer_rlib *bool `android:"arch_variant"`
 }

 type baseCompiler struct {
 	Properties BaseCompilerProperties

 	// Install related
 	dir      string
 	dir64    string
 	subDir   string
 	relative string
 	path     android.InstallPath
 	location installLocation
 	sanitize *sanitize

 	distFile android.OptionalPath
 	// Stripped output file. If Valid(), this file will be installed instead of outputFile.
 	strippedOutputFile android.OptionalPath

 	// If a crate has a source-generated dependency, a copy of the source file
 	// will be available in cargoOutDir (equivalent to Cargo OUT_DIR).
 	cargoOutDir android.ModuleOutPath
 }

 func (compiler *baseCompiler) Disabled() bool {
 	return false
 }

 func (compiler *baseCompiler) SetDisabled() {
 	panic("baseCompiler does not implement SetDisabled()")
 }

 func (compiler *baseCompiler) coverageOutputZipPath() android.OptionalPath {
 	panic("baseCompiler does not implement coverageOutputZipPath()")
 }

 func (compiler *baseCompiler) preferRlib() bool {
 	return Bool(compiler.Properties.Prefer_rlib)
 }

 func (compiler *baseCompiler) stdLinkage(ctx *depsContext) RustLinkage {
 	// For devices, we always link stdlibs in as dylibs by default.
 	if compiler.preferRlib() {
 		return RlibLinkage
 	} else if ctx.Device() {
 		return DylibLinkage
 	} else {
 		return RlibLinkage
 	}
 }

 var _ compiler = (*baseCompiler)(nil)

 func (compiler *baseCompiler) inData() bool {
 	return compiler.location == InstallInData
 }

 func (compiler *baseCompiler) compilerProps() []interface{} {
 	return []interface{}{&compiler.Properties}
 }

 func (compiler *baseCompiler) cfgsToFlags() []string {
 	flags := []string{}
 	for _, cfg := range compiler.Properties.Cfgs {
 		flags = append(flags, "--cfg '"+cfg+"'")
 	}
 	return flags
 }

 func (compiler *baseCompiler) featuresToFlags() []string {
 	flags := []string{}
 	for _, feature := range compiler.Properties.Features {
 		flags = append(flags, "--cfg 'feature=\""+feature+"\"'")
 	}
 	return flags
 }

 func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flags {

 	lintFlags, err := config.RustcLintsForDir(ctx.ModuleDir(), compiler.Properties.Lints)
 	if err != nil {
 		ctx.PropertyErrorf("lints", err.Error())
 	}
 	flags.RustFlags = append(flags.RustFlags, lintFlags)
 	flags.RustFlags = append(flags.RustFlags, compiler.Properties.Flags...)
 	flags.RustFlags = append(flags.RustFlags, compiler.cfgsToFlags()...)
 	flags.RustFlags = append(flags.RustFlags, compiler.featuresToFlags()...)
 	flags.RustdocFlags = append(flags.RustdocFlags, compiler.cfgsToFlags()...)
 	flags.RustdocFlags = append(flags.RustdocFlags, compiler.featuresToFlags()...)
 	flags.RustFlags = append(flags.RustFlags, "--edition="+compiler.edition())
 	flags.RustdocFlags = append(flags.RustdocFlags, "--edition="+compiler.edition())
 	flags.LinkFlags = append(flags.LinkFlags, compiler.Properties.Ld_flags...)
 	flags.GlobalRustFlags = append(flags.GlobalRustFlags, config.GlobalRustFlags...)
 	flags.GlobalRustFlags = append(flags.GlobalRustFlags, ctx.toolchain().ToolchainRustFlags())
 	flags.GlobalLinkFlags = append(flags.GlobalLinkFlags, ctx.toolchain().ToolchainLinkFlags())

 	if ctx.Host() && !ctx.Windows() {
 		rpathPrefix := `\$$ORIGIN/`
 		if ctx.Darwin() {
 			rpathPrefix = "@loader_path/"
 		}

 		var rpath string
 		if ctx.toolchain().Is64Bit() {
 			rpath = "lib64"
 		} else {
 			rpath = "lib"
 		}
 		flags.LinkFlags = append(flags.LinkFlags, "-Wl,-rpath,"+rpathPrefix+rpath)
 		flags.LinkFlags = append(flags.LinkFlags, "-Wl,-rpath,"+rpathPrefix+"../"+rpath)
 	}

 	if ctx.RustModule().UseVndk() {
 		flags.RustFlags = append(flags.RustFlags, "--cfg 'android_vndk'")
 	}

 	return flags
 }

 func (compiler *baseCompiler) compile(ctx ModuleContext, flags Flags, deps PathDeps) android.Path {
 	panic(fmt.Errorf("baseCrater doesn't know how to crate things!"))
 }

 func (compiler *baseCompiler) rustdoc(ctx ModuleContext, flags Flags,
 	deps PathDeps) android.OptionalPath {

 	return android.OptionalPath{}
 }

 func (compiler *baseCompiler) initialize(ctx ModuleContext) {
 	compiler.cargoOutDir = android.PathForModuleOut(ctx, genSubDir)
 }

 func (compiler *baseCompiler) CargoOutDir() android.OptionalPath {
 	return android.OptionalPathForPath(compiler.cargoOutDir)
 }

 func (compiler *baseCompiler) isDependencyRoot() bool {
 	return false
 }

 func (compiler *baseCompiler) strippedOutputFilePath() android.OptionalPath {
 	return compiler.strippedOutputFile
 }

 func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
 	deps.Rlibs = append(deps.Rlibs, compiler.Properties.Rlibs...)
 	deps.Dylibs = append(deps.Dylibs, compiler.Properties.Dylibs...)
 	deps.Rustlibs = append(deps.Rustlibs, compiler.Properties.Rustlibs...)
 	deps.ProcMacros = append(deps.ProcMacros, compiler.Properties.Proc_macros...)
 	deps.StaticLibs = append(deps.StaticLibs, compiler.Properties.Static_libs...)
 	deps.WholeStaticLibs = append(deps.WholeStaticLibs, compiler.Properties.Whole_static_libs...)
 	deps.SharedLibs = append(deps.SharedLibs, compiler.Properties.Shared_libs...)

 	if !Bool(compiler.Properties.No_stdlibs) {
 		for _, stdlib := range config.Stdlibs {
 			// If we're building for the primary arch of the build host, use the compiler's stdlibs
 			if ctx.Target().Os == android.BuildOs {
 				stdlib = stdlib + "_" + ctx.toolchain().RustTriple()
 			}
 			deps.Stdlibs = append(deps.Stdlibs, stdlib)
 		}
 	}
 	return deps
 }

 func bionicDeps(ctx DepsContext, deps Deps, static bool) Deps {
 	bionicLibs := []string{}
 	bionicLibs = append(bionicLibs, "liblog")
 	bionicLibs = append(bionicLibs, "libc")
 	bionicLibs = append(bionicLibs, "libm")
 	bionicLibs = append(bionicLibs, "libdl")

 	if static {
 		deps.StaticLibs = append(deps.StaticLibs, bionicLibs...)
 	} else {
 		deps.SharedLibs = append(deps.SharedLibs, bionicLibs...)
 	}

 	if libRuntimeBuiltins := config.BuiltinsRuntimeLibrary(ctx.toolchain()); libRuntimeBuiltins != "" {
 		deps.StaticLibs = append(deps.StaticLibs, libRuntimeBuiltins)
 	}
 	return deps
 }

 func (compiler *baseCompiler) crateName() string {
 	return compiler.Properties.Crate_name
 }

 func (compiler *baseCompiler) everInstallable() bool {
 	// Most modules are installable, so return true by default.
 	return true
 }

 func (compiler *baseCompiler) installDir(ctx ModuleContext) android.InstallPath {
 	dir := compiler.dir
 	if ctx.toolchain().Is64Bit() && compiler.dir64 != "" {
 		dir = compiler.dir64
 	}
 	if ctx.Target().NativeBridge == android.NativeBridgeEnabled {
 		dir = filepath.Join(dir, ctx.Target().NativeBridgeRelativePath)
 	}
 	if !ctx.Host() && ctx.Config().HasMultilibConflict(ctx.Arch().ArchType) {
 		dir = filepath.Join(dir, ctx.Arch().ArchType.String())
 	}

 	if compiler.location == InstallInData && ctx.RustModule().UseVndk() {
 		dir = filepath.Join(dir, "vendor")
 	}
 	return android.PathForModuleInstall(ctx, dir, compiler.subDir,
 		compiler.relativeInstallPath(), compiler.relative)
 }

 func (compiler *baseCompiler) nativeCoverage() bool {
 	return false
 }

 func (compiler *baseCompiler) install(ctx ModuleContext) {
 	path := ctx.RustModule().OutputFile()
 	compiler.path = ctx.InstallFile(compiler.installDir(ctx), path.Path().Base(), path.Path())
 }

 func (compiler *baseCompiler) getStem(ctx ModuleContext) string {
 	return compiler.getStemWithoutSuffix(ctx) + String(compiler.Properties.Suffix)
 }

 func (compiler *baseCompiler) getStemWithoutSuffix(ctx BaseModuleContext) string {
 	stem := ctx.ModuleName()
 	if String(compiler.Properties.Stem) != "" {
 		stem = String(compiler.Properties.Stem)
 	}

 	return stem
 }

 func (compiler *baseCompiler) relativeInstallPath() string {
 	return String(compiler.Properties.Relative_install_path)
 }

 // Returns the Path for the main source file along with Paths for generated source files from modules listed in srcs.
 func srcPathFromModuleSrcs(ctx ModuleContext, srcs []string) (android.Path, android.Paths) {
 	// The srcs can contain strings with prefix ":".
 	// They are dependent modules of this module, with android.SourceDepTag.
 	// They are not the main source file compiled by rustc.
 	numSrcs := 0
 	srcIndex := 0
 	for i, s := range srcs {
 		if android.SrcIsModule(s) == "" {
 			numSrcs++
 			srcIndex = i
 		}
 	}
 	if numSrcs != 1 {
 		ctx.PropertyErrorf("srcs", incorrectSourcesError)
 	}
 	if srcIndex != 0 {
 		ctx.PropertyErrorf("srcs", "main source file must be the first in srcs")
 	}
 	paths := android.PathsForModuleSrc(ctx, srcs)
 	return paths[srcIndex], paths[1:]
 }
	// Copyright 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 rust

	import (
	"fmt"
	"path/filepath"

	"github.com/google/blueprint/proptools"

	"android/soong/android"
	"android/soong/rust/config"
	)

	type RustLinkage int

	const (
	DefaultLinkage RustLinkage = iota
	RlibLinkage
	DylibLinkage
	)

	func (compiler *baseCompiler) edition() string {
	return proptools.StringDefault(compiler.Properties.Edition, config.DefaultEdition)
	}

	func (compiler *baseCompiler) setNoStdlibs() {
	compiler.Properties.No_stdlibs = proptools.BoolPtr(true)
	}

	func (compiler *baseCompiler) disableLints() {
	compiler.Properties.Lints = proptools.StringPtr("none")
	}

	func NewBaseCompiler(dir, dir64 string, location installLocation) *baseCompiler {
	return &baseCompiler{
	Properties: BaseCompilerProperties{},
	dir: dir,
	dir64: dir64,
	location: location,
	}
	}

	type installLocation int

	const (
	InstallInSystem installLocation = 0
	InstallInData = iota

	incorrectSourcesError = "srcs can only contain one path for a rust file and source providers prefixed by \":\""
	genSubDir = "out/"
	)

	type BaseCompilerProperties struct {
	// path to the source file that is the main entry point of the program (e.g. main.rs or lib.rs)
	Srcs []string `android:"path,arch_variant"`

	// name of the lint set that should be used to validate this module.
	//
	// Possible values are "default" (for using a sensible set of lints
	// depending on the module's location), "android" (for the strictest
	// lint set that applies to all Android platform code), "vendor" (for
	// a relaxed set) and "none" (for ignoring all lint warnings and
	// errors). The default value is "default".
	Lints *string

	// flags to pass to rustc. To enable configuration options or features, use the "cfgs" or "features" properties.
	Flags []string `android:"arch_variant"`

	// flags to pass to the linker
	Ld_flags []string `android:"arch_variant"`

	// list of rust rlib crate dependencies
	Rlibs []string `android:"arch_variant"`

	// list of rust dylib crate dependencies
	Dylibs []string `android:"arch_variant"`

	// list of rust automatic crate dependencies
	Rustlibs []string `android:"arch_variant"`

	// list of rust proc_macro crate dependencies
	Proc_macros []string `android:"arch_variant"`

	// list of C shared library dependencies
	Shared_libs []string `android:"arch_variant"`

	// list of C static library dependencies. These dependencies do not normally propagate to dependents
	// and may need to be redeclared. See whole_static_libs for bundling static dependencies into a library.
	Static_libs []string `android:"arch_variant"`

	// Similar to static_libs, but will bundle the static library dependency into a library. This is helpful
	// to avoid having to redeclare the dependency for dependents of this library, but in some cases may also
	// result in bloat if multiple dependencies all include the same static library whole.
	//
	// The common use case for this is when the static library is unlikely to be a dependency of other modules to avoid
	// having to redeclare the static library dependency for every dependent module.
	// If you are not sure what to, for rust_library modules most static dependencies should go in static_libraries,
	// and for rust_ffi modules most static dependencies should go into whole_static_libraries.
	//
	// For rust_ffi static variants, these libraries will be included in the resulting static library archive.
	//
	// For rust_library rlib variants, these libraries will be bundled into the resulting rlib library. This will
	// include all of the static libraries symbols in any dylibs or binaries which use this rlib as well.
	Whole_static_libs []string `android:"arch_variant"`

	// crate name, required for modules which produce Rust libraries: rust_library, rust_ffi and SourceProvider
	// modules which create library variants (rust_bindgen). This must be the expected extern crate name used in
	// source, and is required to conform to an enforced format matching library output files (if the output file is
	// lib<someName><suffix>, the crate_name property must be <someName>).
	Crate_name string `android:"arch_variant"`

	// list of features to enable for this crate
	Features []string `android:"arch_variant"`

	// list of configuration options to enable for this crate. To enable features, use the "features" property.
	Cfgs []string `android:"arch_variant"`

	// specific rust edition that should be used if the default version is not desired
	Edition *string `android:"arch_variant"`

	// sets name of the output
	Stem *string `android:"arch_variant"`

	// append to name of output
	Suffix *string `android:"arch_variant"`

	// install to a subdirectory of the default install path for the module
	Relative_install_path *string `android:"arch_variant"`

	// whether to suppress inclusion of standard crates - defaults to false
	No_stdlibs *bool

	// Change the rustlibs linkage to select rlib linkage by default for device targets.
	// Also link libstd as an rlib as well on device targets.
	// Note: This is the default behavior for host targets.
	//
	// This is primarily meant for rust_binary and rust_ffi modules where the default
	// linkage of libstd might need to be overridden in some use cases. This should
	// generally be avoided with other module types since it may cause collisions at
	// linkage if all dependencies of the root binary module do not link against libstd\
	// the same way.
	Prefer_rlib *bool `android:"arch_variant"`
	}

	type baseCompiler struct {
	Properties BaseCompilerProperties

	// Install related
	dir string
	dir64 string
	subDir string
	relative string
	path android.InstallPath
	location installLocation
	sanitize *sanitize

	distFile android.OptionalPath
	// Stripped output file. If Valid(), this file will be installed instead of outputFile.
	strippedOutputFile android.OptionalPath

	// If a crate has a source-generated dependency, a copy of the source file
	// will be available in cargoOutDir (equivalent to Cargo OUT_DIR).
	cargoOutDir android.ModuleOutPath
	}

	func (compiler *baseCompiler) Disabled() bool {
	return false
	}

	func (compiler *baseCompiler) SetDisabled() {
	panic("baseCompiler does not implement SetDisabled()")
	}

	func (compiler *baseCompiler) coverageOutputZipPath() android.OptionalPath {
	panic("baseCompiler does not implement coverageOutputZipPath()")
	}

	func (compiler *baseCompiler) preferRlib() bool {
	return Bool(compiler.Properties.Prefer_rlib)
	}

	func (compiler baseCompiler) stdLinkage(ctx depsContext) RustLinkage {
	// For devices, we always link stdlibs in as dylibs by default.
	if compiler.preferRlib() {
	return RlibLinkage
	} else if ctx.Device() {
	return DylibLinkage
	} else {
	return RlibLinkage
	}
	}

	var _ compiler = (*baseCompiler)(nil)

	func (compiler *baseCompiler) inData() bool {
	return compiler.location == InstallInData
	}

	func (compiler *baseCompiler) compilerProps() []interface{} {
	return []interface{}{&compiler.Properties}
	}

	func (compiler *baseCompiler) cfgsToFlags() []string {
	flags := []string{}
	for _, cfg := range compiler.Properties.Cfgs {
	flags = append(flags, "--cfg '"+cfg+"'")
	}
	return flags
	}

	func (compiler *baseCompiler) featuresToFlags() []string {
	flags := []string{}
	for _, feature := range compiler.Properties.Features {
	flags = append(flags, "--cfg 'feature=\""+feature+"\"'")
	}
	return flags
	}

	func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flags {

	lintFlags, err := config.RustcLintsForDir(ctx.ModuleDir(), compiler.Properties.Lints)
	if err != nil {
	ctx.PropertyErrorf("lints", err.Error())
	}
	flags.RustFlags = append(flags.RustFlags, lintFlags)
	flags.RustFlags = append(flags.RustFlags, compiler.Properties.Flags...)
	flags.RustFlags = append(flags.RustFlags, compiler.cfgsToFlags()...)
	flags.RustFlags = append(flags.RustFlags, compiler.featuresToFlags()...)
	flags.RustdocFlags = append(flags.RustdocFlags, compiler.cfgsToFlags()...)
	flags.RustdocFlags = append(flags.RustdocFlags, compiler.featuresToFlags()...)
	flags.RustFlags = append(flags.RustFlags, "--edition="+compiler.edition())
	flags.RustdocFlags = append(flags.RustdocFlags, "--edition="+compiler.edition())
	flags.LinkFlags = append(flags.LinkFlags, compiler.Properties.Ld_flags...)
	flags.GlobalRustFlags = append(flags.GlobalRustFlags, config.GlobalRustFlags...)
	flags.GlobalRustFlags = append(flags.GlobalRustFlags, ctx.toolchain().ToolchainRustFlags())
	flags.GlobalLinkFlags = append(flags.GlobalLinkFlags, ctx.toolchain().ToolchainLinkFlags())

	if ctx.Host() && !ctx.Windows() {
	rpathPrefix := `\$$ORIGIN/`
	if ctx.Darwin() {
	rpathPrefix = "@loader_path/"
	}

	var rpath string
	if ctx.toolchain().Is64Bit() {
	rpath = "lib64"
	} else {
	rpath = "lib"
	}
	flags.LinkFlags = append(flags.LinkFlags, "-Wl,-rpath,"+rpathPrefix+rpath)
	flags.LinkFlags = append(flags.LinkFlags, "-Wl,-rpath,"+rpathPrefix+"../"+rpath)
	}

	if ctx.RustModule().UseVndk() {
	flags.RustFlags = append(flags.RustFlags, "--cfg 'android_vndk'")
	}

	return flags
	}

	func (compiler *baseCompiler) compile(ctx ModuleContext, flags Flags, deps PathDeps) android.Path {
	panic(fmt.Errorf("baseCrater doesn't know how to crate things!"))
	}

	func (compiler *baseCompiler) rustdoc(ctx ModuleContext, flags Flags,
	deps PathDeps) android.OptionalPath {

	return android.OptionalPath{}
	}

	func (compiler *baseCompiler) initialize(ctx ModuleContext) {
	compiler.cargoOutDir = android.PathForModuleOut(ctx, genSubDir)
	}

	func (compiler *baseCompiler) CargoOutDir() android.OptionalPath {
	return android.OptionalPathForPath(compiler.cargoOutDir)
	}

	func (compiler *baseCompiler) isDependencyRoot() bool {
	return false
	}

	func (compiler *baseCompiler) strippedOutputFilePath() android.OptionalPath {
	return compiler.strippedOutputFile
	}

	func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
	deps.Rlibs = append(deps.Rlibs, compiler.Properties.Rlibs...)
	deps.Dylibs = append(deps.Dylibs, compiler.Properties.Dylibs...)
	deps.Rustlibs = append(deps.Rustlibs, compiler.Properties.Rustlibs...)
	deps.ProcMacros = append(deps.ProcMacros, compiler.Properties.Proc_macros...)
	deps.StaticLibs = append(deps.StaticLibs, compiler.Properties.Static_libs...)
	deps.WholeStaticLibs = append(deps.WholeStaticLibs, compiler.Properties.Whole_static_libs...)
	deps.SharedLibs = append(deps.SharedLibs, compiler.Properties.Shared_libs...)

	if !Bool(compiler.Properties.No_stdlibs) {
	for _, stdlib := range config.Stdlibs {
	// If we're building for the primary arch of the build host, use the compiler's stdlibs
	if ctx.Target().Os == android.BuildOs {
	stdlib = stdlib + "_" + ctx.toolchain().RustTriple()
	}
	deps.Stdlibs = append(deps.Stdlibs, stdlib)
	}
	}
	return deps
	}

	func bionicDeps(ctx DepsContext, deps Deps, static bool) Deps {
	bionicLibs := []string{}
	bionicLibs = append(bionicLibs, "liblog")
	bionicLibs = append(bionicLibs, "libc")
	bionicLibs = append(bionicLibs, "libm")
	bionicLibs = append(bionicLibs, "libdl")

	if static {
	deps.StaticLibs = append(deps.StaticLibs, bionicLibs...)
	} else {
	deps.SharedLibs = append(deps.SharedLibs, bionicLibs...)
	}

	if libRuntimeBuiltins := config.BuiltinsRuntimeLibrary(ctx.toolchain()); libRuntimeBuiltins != "" {
	deps.StaticLibs = append(deps.StaticLibs, libRuntimeBuiltins)
	}
	return deps
	}

	func (compiler *baseCompiler) crateName() string {
	return compiler.Properties.Crate_name
	}

	func (compiler *baseCompiler) everInstallable() bool {
	// Most modules are installable, so return true by default.
	return true
	}

	func (compiler *baseCompiler) installDir(ctx ModuleContext) android.InstallPath {
	dir := compiler.dir
	if ctx.toolchain().Is64Bit() && compiler.dir64 != "" {
	dir = compiler.dir64
	}
	if ctx.Target().NativeBridge == android.NativeBridgeEnabled {
	dir = filepath.Join(dir, ctx.Target().NativeBridgeRelativePath)
	}
	if !ctx.Host() && ctx.Config().HasMultilibConflict(ctx.Arch().ArchType) {
	dir = filepath.Join(dir, ctx.Arch().ArchType.String())
	}

	if compiler.location == InstallInData && ctx.RustModule().UseVndk() {
	dir = filepath.Join(dir, "vendor")
	}
	return android.PathForModuleInstall(ctx, dir, compiler.subDir,
	compiler.relativeInstallPath(), compiler.relative)
	}

	func (compiler *baseCompiler) nativeCoverage() bool {
	return false
	}

	func (compiler *baseCompiler) install(ctx ModuleContext) {
	path := ctx.RustModule().OutputFile()
	compiler.path = ctx.InstallFile(compiler.installDir(ctx), path.Path().Base(), path.Path())
	}

	func (compiler *baseCompiler) getStem(ctx ModuleContext) string {
	return compiler.getStemWithoutSuffix(ctx) + String(compiler.Properties.Suffix)
	}

	func (compiler *baseCompiler) getStemWithoutSuffix(ctx BaseModuleContext) string {
	stem := ctx.ModuleName()
	if String(compiler.Properties.Stem) != "" {
	stem = String(compiler.Properties.Stem)
	}

	return stem
	}

	func (compiler *baseCompiler) relativeInstallPath() string {
	return String(compiler.Properties.Relative_install_path)
	}

	// Returns the Path for the main source file along with Paths for generated source files from modules listed in srcs.
	func srcPathFromModuleSrcs(ctx ModuleContext, srcs []string) (android.Path, android.Paths) {
	// The srcs can contain strings with prefix ":".
	// They are dependent modules of this module, with android.SourceDepTag.
	// They are not the main source file compiled by rustc.
	numSrcs := 0
	srcIndex := 0
	for i, s := range srcs {
	if android.SrcIsModule(s) == "" {
	numSrcs++
	srcIndex = i
	}
	}
	if numSrcs != 1 {
	ctx.PropertyErrorf("srcs", incorrectSourcesError)
	}
	if srcIndex != 0 {
	ctx.PropertyErrorf("srcs", "main source file must be the first in srcs")
	}
	paths := android.PathsForModuleSrc(ctx, srcs)
	return paths[srcIndex], paths[1:]
	}