Merge "rust: Add libstd linkage mutator for rlibs."
diff --git a/rust/androidmk.go b/rust/androidmk.go
index edae0e6..5a33f77 100644
--- a/rust/androidmk.go
+++ b/rust/androidmk.go
@@ -178,6 +178,10 @@
 }
 
 func (compiler *baseCompiler) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
+	if compiler.path == (android.InstallPath{}) {
+		return
+	}
+
 	var unstrippedOutputFile android.OptionalPath
 	// Soong installation is only supported for host modules. Have Make
 	// installation trigger Soong installation.
diff --git a/rust/binary_test.go b/rust/binary_test.go
index cfef57a..394abfc 100644
--- a/rust/binary_test.go
+++ b/rust/binary_test.go
@@ -40,7 +40,7 @@
 	fizzBuzzHost := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Module().(*Module)
 	fizzBuzzDevice := ctx.ModuleForTests("fizz-buzz", "android_arm64_armv8-a").Module().(*Module)
 
-	if !android.InList("libfoo", fizzBuzzHost.Properties.AndroidMkRlibs) {
+	if !android.InList("libfoo.rlib-std", fizzBuzzHost.Properties.AndroidMkRlibs) {
 		t.Errorf("rustlibs dependency libfoo should be an rlib dep for host modules")
 	}
 
diff --git a/rust/compiler.go b/rust/compiler.go
index 664578d..aeb904b 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -146,8 +146,13 @@
 	panic("baseCompiler does not implement coverageOutputZipPath()")
 }
 
-func (compiler *baseCompiler) static() bool {
-	return false
+func (compiler *baseCompiler) staticStd(ctx *depsContext) bool {
+	// For devices, we always link stdlibs in as dylibs by default.
+	if ctx.Device() {
+		return false
+	} else {
+		return true
+	}
 }
 
 var _ compiler = (*baseCompiler)(nil)
@@ -221,15 +226,7 @@
 				stdlib = stdlib + "_" + ctx.toolchain().RustTriple()
 			}
 
-			// For devices, we always link stdlibs in as dylibs except for ffi static libraries.
-			// (rustc does not support linking libstd as a dylib for ffi static libraries)
-			if ctx.Host() {
-				deps.Rustlibs = append(deps.Rustlibs, stdlib)
-			} else if ctx.RustModule().compiler.static() {
-				deps.Rlibs = append(deps.Rlibs, stdlib)
-			} else {
-				deps.Dylibs = append(deps.Dylibs, stdlib)
-			}
+			deps.Stdlibs = append(deps.Stdlibs, stdlib)
 		}
 	}
 	return deps
diff --git a/rust/compiler_test.go b/rust/compiler_test.go
index 56a8ef8..a25523c 100644
--- a/rust/compiler_test.go
+++ b/rust/compiler_test.go
@@ -191,7 +191,7 @@
 			crate_name: "foo",
 		}`)
 	fizz := ctx.ModuleForTests("fizz", "android_arm64_armv8-a").Module().(*Module)
-	fooRlib := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib").Module().(*Module)
+	fooRlib := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib_dylib-std").Module().(*Module)
 	fooDylib := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_dylib").Module().(*Module)
 
 	if !android.InList("libstd", fizz.Properties.AndroidMkDylibs) {
diff --git a/rust/coverage_test.go b/rust/coverage_test.go
index 73673d0..90155ca 100644
--- a/rust/coverage_test.go
+++ b/rust/coverage_test.go
@@ -154,12 +154,12 @@
 	}
 
 	// Make sure the expected inputs are provided to the zip rule.
-	if !android.SuffixInList(fizzZipInputs, "android_arm64_armv8-a_rlib_cov/librlib.gcno") ||
+	if !android.SuffixInList(fizzZipInputs, "android_arm64_armv8-a_rlib_dylib-std_cov/librlib.gcno") ||
 		!android.SuffixInList(fizzZipInputs, "android_arm64_armv8-a_static_cov/libbaz.gcno") ||
 		!android.SuffixInList(fizzZipInputs, "android_arm64_armv8-a_cov/fizz.gcno") {
 		t.Fatalf("missing expected coverage files for rust 'fizz' binary: %#v", fizzZipInputs)
 	}
-	if !android.SuffixInList(libfooZipInputs, "android_arm64_armv8-a_rlib_cov/librlib.gcno") ||
+	if !android.SuffixInList(libfooZipInputs, "android_arm64_armv8-a_rlib_dylib-std_cov/librlib.gcno") ||
 		!android.SuffixInList(libfooZipInputs, "android_arm64_armv8-a_dylib_cov/libfoo.dylib.gcno") {
 		t.Fatalf("missing expected coverage files for rust 'fizz' binary: %#v", libfooZipInputs)
 	}
diff --git a/rust/library.go b/rust/library.go
index a442933..4931f19 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -21,6 +21,11 @@
 	"android/soong/android"
 )
 
+var (
+	DylibStdlibSuffix = ".dylib-std"
+	RlibStdlibSuffix  = ".rlib-std"
+)
+
 func init() {
 	android.RegisterModuleType("rust_library", RustLibraryFactory)
 	android.RegisterModuleType("rust_library_dylib", RustLibraryDylibFactory)
@@ -49,6 +54,9 @@
 
 	// path to include directories to pass to cc_* modules, only relevant for static/shared variants.
 	Include_dirs []string `android:"path,arch_variant"`
+
+	// Whether this library is part of the Rust toolchain sysroot.
+	Sysroot *bool
 }
 
 type LibraryMutatedProperties struct {
@@ -73,6 +81,9 @@
 	// This variant is disabled and should not be compiled
 	// (used for SourceProvider variants that produce only source)
 	VariantIsDisabled bool `blueprint:"mutated"`
+
+	// Whether this library variant should be link libstd via rlibs
+	VariantIsStaticStd bool `blueprint:"mutated"`
 }
 
 type libraryDecorator struct {
@@ -91,6 +102,7 @@
 	dylib() bool
 	static() bool
 	shared() bool
+	sysroot() bool
 
 	// Returns true if the build options for the module have selected a particular build type
 	buildRlib() bool
@@ -104,6 +116,10 @@
 	setShared()
 	setStatic()
 
+	// Set libstd linkage
+	setRlibStd()
+	setDylibStd()
+
 	// Build a specific library variant
 	BuildOnlyFFI()
 	BuildOnlyRust()
@@ -121,6 +137,10 @@
 	return library.MutatedProperties.VariantIsRlib
 }
 
+func (library *libraryDecorator) sysroot() bool {
+	return Bool(library.Properties.Sysroot)
+}
+
 func (library *libraryDecorator) dylib() bool {
 	return library.MutatedProperties.VariantIsDylib
 }
@@ -133,6 +153,11 @@
 	return library.MutatedProperties.VariantIsStatic
 }
 
+func (library *libraryDecorator) staticStd(ctx *depsContext) bool {
+	// libraries should only request the staticStd when building a static FFI or when variant is staticStd
+	return library.static() || library.MutatedProperties.VariantIsStaticStd
+}
+
 func (library *libraryDecorator) buildRlib() bool {
 	return library.MutatedProperties.BuildRlib && BoolDefault(library.Properties.Rlib.Enabled, true)
 }
@@ -163,6 +188,14 @@
 	library.MutatedProperties.VariantIsShared = false
 }
 
+func (library *libraryDecorator) setRlibStd() {
+	library.MutatedProperties.VariantIsStaticStd = true
+}
+
+func (library *libraryDecorator) setDylibStd() {
+	library.MutatedProperties.VariantIsStaticStd = false
+}
+
 func (library *libraryDecorator) setShared() {
 	library.MutatedProperties.VariantIsStatic = false
 	library.MutatedProperties.VariantIsShared = true
@@ -450,6 +483,13 @@
 	return stem + String(library.baseCompiler.Properties.Suffix)
 }
 
+func (library *libraryDecorator) install(ctx ModuleContext) {
+	// Only shared and dylib variants make sense to install.
+	if library.shared() || library.dylib() {
+		library.baseCompiler.install(ctx)
+	}
+}
+
 func (library *libraryDecorator) Disabled() bool {
 	return library.MutatedProperties.VariantIsDisabled
 }
@@ -493,7 +533,6 @@
 				dylib := modules[1].(*Module)
 				rlib.compiler.(libraryInterface).setRlib()
 				dylib.compiler.(libraryInterface).setDylib()
-
 				if m.sourceProvider != nil {
 					// This library is SourceProvider generated, so the non-library-producing
 					// variant needs to disable it's compiler and skip installation.
@@ -515,3 +554,23 @@
 		}
 	}
 }
+
+func LibstdMutator(mctx android.BottomUpMutatorContext) {
+	if m, ok := mctx.Module().(*Module); ok && m.compiler != nil && !m.compiler.Disabled() {
+		switch library := m.compiler.(type) {
+		case libraryInterface:
+			// Only create a variant if a library is actually being built.
+			if library.rlib() && !library.sysroot() {
+				variants := []string{"rlib-std", "dylib-std"}
+				modules := mctx.CreateLocalVariations(variants...)
+
+				rlib := modules[0].(*Module)
+				dylib := modules[1].(*Module)
+				rlib.compiler.(libraryInterface).setRlibStd()
+				dylib.compiler.(libraryInterface).setDylibStd()
+				rlib.Properties.SubName += RlibStdlibSuffix
+				dylib.Properties.SubName += DylibStdlibSuffix
+			}
+		}
+	}
+}
diff --git a/rust/library_test.go b/rust/library_test.go
index f1bc050..fec3992 100644
--- a/rust/library_test.go
+++ b/rust/library_test.go
@@ -37,7 +37,7 @@
                 }`)
 
 	// Test all variants are being built.
-	libfooRlib := ctx.ModuleForTests("libfoo", "linux_glibc_x86_64_rlib").Output("libfoo.rlib")
+	libfooRlib := ctx.ModuleForTests("libfoo", "linux_glibc_x86_64_rlib_rlib-std").Output("libfoo.rlib")
 	libfooDylib := ctx.ModuleForTests("libfoo", "linux_glibc_x86_64_dylib").Output("libfoo.dylib.so")
 	libfooStatic := ctx.ModuleForTests("libfoo.ffi", "linux_glibc_x86_64_static").Output("libfoo.ffi.a")
 	libfooShared := ctx.ModuleForTests("libfoo.ffi", "linux_glibc_x86_64_shared").Output("libfoo.ffi.so")
@@ -182,14 +182,14 @@
                         rustlibs: ["libbar"],
                 }`)
 
-	libfooRlib := ctx.ModuleForTests("libfoo", "linux_glibc_x86_64_rlib")
+	libfooRlib := ctx.ModuleForTests("libfoo", "linux_glibc_x86_64_rlib_rlib-std")
 	libfooDylib := ctx.ModuleForTests("libfoo", "linux_glibc_x86_64_dylib")
 	libfooStatic := ctx.ModuleForTests("libfoo.ffi", "linux_glibc_x86_64_static")
 	libfooShared := ctx.ModuleForTests("libfoo.ffi", "linux_glibc_x86_64_shared")
 
 	for _, static := range []android.TestingModule{libfooRlib, libfooStatic} {
-		if !android.InList("libbar", static.Module().(*Module).Properties.AndroidMkRlibs) {
-			t.Errorf("libbar not present as static dependency in static lib")
+		if !android.InList("libbar.rlib-std", static.Module().(*Module).Properties.AndroidMkRlibs) {
+			t.Errorf("libbar not present as rlib dependency in static lib")
 		}
 		if android.InList("libbar", static.Module().(*Module).Properties.AndroidMkDylibs) {
 			t.Errorf("libbar present as dynamic dependency in static lib")
@@ -200,8 +200,8 @@
 		if !android.InList("libbar", dyn.Module().(*Module).Properties.AndroidMkDylibs) {
 			t.Errorf("libbar not present as dynamic dependency in dynamic lib")
 		}
-		if android.InList("libbar", dyn.Module().(*Module).Properties.AndroidMkRlibs) {
-			t.Errorf("libbar present as static dependency in dynamic lib")
+		if android.InList("libbar.dylib-std", dyn.Module().(*Module).Properties.AndroidMkRlibs) {
+			t.Errorf("libbar present as rlib dependency in dynamic lib")
 		}
 
 	}
@@ -238,3 +238,45 @@
 		t.Errorf("stripped version of bar has been generated")
 	}
 }
+
+func TestLibstdLinkage(t *testing.T) {
+	ctx := testRust(t, `
+		rust_library {
+			name: "libfoo",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+		}
+		rust_ffi {
+			name: "libbar",
+			srcs: ["foo.rs"],
+			crate_name: "bar",
+			rustlibs: ["libfoo"],
+		}`)
+
+	libfooDylib := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_dylib").Module().(*Module)
+	libfooRlibStatic := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib_rlib-std").Module().(*Module)
+	libfooRlibDynamic := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib_dylib-std").Module().(*Module)
+
+	libbarShared := ctx.ModuleForTests("libbar", "android_arm64_armv8-a_shared").Module().(*Module)
+	libbarStatic := ctx.ModuleForTests("libbar", "android_arm64_armv8-a_static").Module().(*Module)
+
+	if !android.InList("libstd", libfooRlibStatic.Properties.AndroidMkRlibs) {
+		t.Errorf("rlib-std variant for device rust_library_rlib does not link libstd as an rlib")
+	}
+	if !android.InList("libstd", libfooRlibDynamic.Properties.AndroidMkDylibs) {
+		t.Errorf("dylib-std variant for device rust_library_rlib does not link libstd as an dylib")
+	}
+	if !android.InList("libstd", libfooDylib.Properties.AndroidMkDylibs) {
+		t.Errorf("Device rust_library_dylib does not link libstd as an dylib")
+	}
+
+	if !android.InList("libstd", libbarShared.Properties.AndroidMkDylibs) {
+		t.Errorf("Device rust_ffi_shared does not link libstd as an dylib")
+	}
+	if !android.InList("libstd", libbarStatic.Properties.AndroidMkRlibs) {
+		t.Errorf("Device rust_ffi_static does not link libstd as an rlib")
+	}
+	if !android.InList("libfoo.rlib-std", libbarStatic.Properties.AndroidMkRlibs) {
+		t.Errorf("Device rust_ffi_static does not link dependent rustlib rlib-std variant")
+	}
+}
diff --git a/rust/rust.go b/rust/rust.go
index b98992c..e561477 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -40,6 +40,7 @@
 	android.RegisterModuleType("rust_defaults", defaultsFactory)
 	android.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
 		ctx.BottomUp("rust_libraries", LibraryMutator).Parallel()
+		ctx.BottomUp("rust_stdlinkage", LibstdMutator).Parallel()
 		ctx.BottomUp("rust_begin", BeginMutator).Parallel()
 	})
 	pctx.Import("android/soong/rust/config")
@@ -237,6 +238,7 @@
 	Dylibs     []string
 	Rlibs      []string
 	Rustlibs   []string
+	Stdlibs    []string
 	ProcMacros []string
 	SharedLibs []string
 	StaticLibs []string
@@ -293,7 +295,7 @@
 	Disabled() bool
 	SetDisabled()
 
-	static() bool
+	staticStd(ctx *depsContext) bool
 }
 
 type exportedFlagsProducer interface {
@@ -782,14 +784,15 @@
 				directDylibDeps = append(directDylibDeps, rustDep)
 				mod.Properties.AndroidMkDylibs = append(mod.Properties.AndroidMkDylibs, depName)
 			case rlibDepTag:
+
 				rlib, ok := rustDep.compiler.(libraryInterface)
 				if !ok || !rlib.rlib() {
-					ctx.ModuleErrorf("mod %q not an rlib library", depName)
+					ctx.ModuleErrorf("mod %q not an rlib library", depName+rustDep.Properties.SubName)
 					return
 				}
 				depPaths.coverageFiles = append(depPaths.coverageFiles, rustDep.CoverageFiles()...)
 				directRlibDeps = append(directRlibDeps, rustDep)
-				mod.Properties.AndroidMkRlibs = append(mod.Properties.AndroidMkRlibs, depName)
+				mod.Properties.AndroidMkRlibs = append(mod.Properties.AndroidMkRlibs, depName+rustDep.Properties.SubName)
 			case procMacroDepTag:
 				directProcMacroDeps = append(directProcMacroDeps, rustDep)
 				mod.Properties.AndroidMkProcMacroLibs = append(mod.Properties.AndroidMkProcMacroLibs, depName)
@@ -976,8 +979,19 @@
 		commonDepVariations = append(commonDepVariations,
 			blueprint.Variation{Mutator: "image", Variation: android.CoreVariation})
 	}
+	stdLinkage := "dylib-std"
+	if mod.compiler.staticStd(ctx) {
+		stdLinkage = "rlib-std"
+	}
+
+	rlibDepVariations := commonDepVariations
+	if lib, ok := mod.compiler.(libraryInterface); !ok || !lib.sysroot() {
+		rlibDepVariations = append(rlibDepVariations,
+			blueprint.Variation{Mutator: "rust_stdlinkage", Variation: stdLinkage})
+	}
+
 	actx.AddVariationDependencies(
-		append(commonDepVariations, []blueprint.Variation{
+		append(rlibDepVariations, []blueprint.Variation{
 			{Mutator: "rust_libraries", Variation: "rlib"}}...),
 		rlibDepTag, deps.Rlibs...)
 	actx.AddVariationDependencies(
@@ -987,12 +1001,27 @@
 
 	if deps.Rustlibs != nil && !mod.compiler.Disabled() {
 		autoDep := mod.compiler.(autoDeppable).autoDep(ctx)
-		actx.AddVariationDependencies(
-			append(commonDepVariations, []blueprint.Variation{
-				{Mutator: "rust_libraries", Variation: autoDep.variation}}...),
-			autoDep.depTag, deps.Rustlibs...)
+		if autoDep.depTag == rlibDepTag {
+			actx.AddVariationDependencies(
+				append(rlibDepVariations, blueprint.Variation{Mutator: "rust_libraries", Variation: autoDep.variation}),
+				autoDep.depTag, deps.Rustlibs...)
+		} else {
+			actx.AddVariationDependencies(
+				append(commonDepVariations, blueprint.Variation{Mutator: "rust_libraries", Variation: autoDep.variation}),
+				autoDep.depTag, deps.Rustlibs...)
+		}
 	}
-
+	if deps.Stdlibs != nil {
+		if mod.compiler.staticStd(ctx) {
+			actx.AddVariationDependencies(
+				append(commonDepVariations, blueprint.Variation{Mutator: "rust_libraries", Variation: "rlib"}),
+				rlibDepTag, deps.Stdlibs...)
+		} else {
+			actx.AddVariationDependencies(
+				append(commonDepVariations, blueprint.Variation{Mutator: "rust_libraries", Variation: "dylib"}),
+				dylibDepTag, deps.Stdlibs...)
+		}
+	}
 	actx.AddVariationDependencies(append(commonDepVariations,
 		blueprint.Variation{Mutator: "link", Variation: "shared"}),
 		cc.SharedDepTag(), deps.SharedLibs...)
diff --git a/rust/rust_test.go b/rust/rust_test.go
index 89ce359..4842a4c 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -189,7 +189,7 @@
 		t.Errorf("Dylib dependency not detected (dependency missing from AndroidMkDylibs)")
 	}
 
-	if !android.InList("librlib", module.Properties.AndroidMkRlibs) {
+	if !android.InList("librlib.rlib-std", module.Properties.AndroidMkRlibs) {
 		t.Errorf("Rlib dependency not detected (dependency missing from AndroidMkRlibs)")
 	}
 
@@ -253,7 +253,7 @@
         }
 	`)
 
-	libfoo := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib").Rule("rustc")
+	libfoo := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib_dylib-std").Rule("rustc")
 	if !android.SuffixInList(libfoo.Implicits.Strings(), "/out/bindings.rs") {
 		t.Errorf("rust_bindgen generated source not included as implicit input for libfoo; Implicits %#v", libfoo.Implicits.Strings())
 	}
@@ -279,15 +279,15 @@
 
 	// Check that our bindings are picked up as crate dependencies as well
 	libfooMod := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_dylib").Module().(*Module)
-	if !android.InList("libbindings", libfooMod.Properties.AndroidMkRlibs) {
+	if !android.InList("libbindings.dylib-std", libfooMod.Properties.AndroidMkRlibs) {
 		t.Errorf("bindgen dependency not detected as a rlib dependency (dependency missing from AndroidMkRlibs)")
 	}
 	fizzBuzzMod := ctx.ModuleForTests("fizz-buzz-dep", "android_arm64_armv8-a").Module().(*Module)
-	if !android.InList("libbindings", fizzBuzzMod.Properties.AndroidMkRlibs) {
+	if !android.InList("libbindings.dylib-std", fizzBuzzMod.Properties.AndroidMkRlibs) {
 		t.Errorf("bindgen dependency not detected as a rlib dependency (dependency missing from AndroidMkRlibs)")
 	}
 	libprocmacroMod := ctx.ModuleForTests("libprocmacro", "linux_glibc_x86_64").Module().(*Module)
-	if !android.InList("libbindings", libprocmacroMod.Properties.AndroidMkRlibs) {
+	if !android.InList("libbindings.rlib-std", libprocmacroMod.Properties.AndroidMkRlibs) {
 		t.Errorf("bindgen dependency not detected as a rlib dependency (dependency missing from AndroidMkRlibs)")
 	}
 
@@ -365,6 +365,6 @@
 			crate_name: "foo",
 		}`)
 
-	_ = ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib")
-	_ = ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_rlib")
+	_ = ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_rlib_dylib-std")
+	_ = ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_rlib_dylib-std")
 }
diff --git a/rust/test.go b/rust/test.go
index d93fc31..0679448 100644
--- a/rust/test.go
+++ b/rust/test.go
@@ -133,3 +133,7 @@
 	module, _ := NewRustTest(android.HostSupported)
 	return module.Init()
 }
+
+func (test *testDecorator) staticStd(ctx *depsContext) bool {
+	return true
+}
diff --git a/rust/test_test.go b/rust/test_test.go
index 2382b18..fea2ad0 100644
--- a/rust/test_test.go
+++ b/rust/test_test.go
@@ -17,6 +17,8 @@
 import (
 	"strings"
 	"testing"
+
+	"android/soong/android"
 )
 
 func TestRustTest(t *testing.T) {
@@ -33,3 +35,35 @@
 		t.Errorf("wrong output path: %v;  expected: %v", outPath, expectedOut)
 	}
 }
+
+func TestRustTestLinkage(t *testing.T) {
+	ctx := testRust(t, `
+		rust_test {
+			name: "my_test",
+			srcs: ["foo.rs"],
+			rustlibs: ["libfoo"],
+            rlibs: ["libbar"],
+		}
+		rust_library {
+			name: "libfoo",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+		}
+		rust_library {
+			name: "libbar",
+			srcs: ["foo.rs"],
+			crate_name: "bar",
+		}`)
+
+	testingModule := ctx.ModuleForTests("my_test", "android_arm64_armv8-a").Module().(*Module)
+
+	if !android.InList("libfoo.rlib-std", testingModule.Properties.AndroidMkRlibs) {
+		t.Errorf("rlib-std variant for libfoo not detected as a rustlib-defined rlib dependency for device rust_test module")
+	}
+	if !android.InList("libbar.rlib-std", testingModule.Properties.AndroidMkRlibs) {
+		t.Errorf("rlib-std variant for libbar not detected as an rlib dependency for device rust_test module")
+	}
+	if !android.InList("libstd", testingModule.Properties.AndroidMkRlibs) {
+		t.Errorf("Device rust_test module 'my_test' does not link libstd as an rlib")
+	}
+}
diff --git a/rust/testing.go b/rust/testing.go
index 0144c82..ee303ed 100644
--- a/rust/testing.go
+++ b/rust/testing.go
@@ -32,6 +32,7 @@
                                     srcs: ["libstd.so"],
                                 },
 				host_supported: true,
+				sysroot: true,
 		}
 		rust_prebuilt_library {
 				name: "libtest_x86_64-unknown-linux-gnu",
@@ -43,6 +44,7 @@
                                     srcs: ["libtest.so"],
                                 },
 				host_supported: true,
+				sysroot: true,
 		}
 		rust_prebuilt_library {
 				name: "libstd_x86_64-apple-darwin",
@@ -54,6 +56,7 @@
                                     srcs: ["libstd.so"],
                                 },
 				host_supported: true,
+				sysroot: true,
 		}
 		rust_prebuilt_library {
 				name: "libtest_x86_64-apple-darwin",
@@ -65,6 +68,7 @@
                                     srcs: ["libtest.so"],
                                 },
 				host_supported: true,
+				sysroot: true,
 		}
 		//////////////////////////////
 		// Device module requirements
@@ -82,6 +86,7 @@
 			no_stdlibs: true,
 			host_supported: true,
                         native_coverage: false,
+			sysroot: true,
 		}
 		rust_library {
 			name: "libtest",
@@ -90,6 +95,7 @@
 			no_stdlibs: true,
 			host_supported: true,
                         native_coverage: false,
+			sysroot: true,
 		}
 		rust_library {
 			name: "libprotobuf",
@@ -134,6 +140,7 @@
 	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
 		// rust mutators
 		ctx.BottomUp("rust_libraries", LibraryMutator).Parallel()
+		ctx.BottomUp("rust_stdlinkage", LibstdMutator).Parallel()
 		ctx.BottomUp("rust_begin", BeginMutator).Parallel()
 	})
 	ctx.RegisterSingletonType("rust_project_generator", rustProjectGeneratorSingleton)