Add gcov coverage support to Rust modules.

This adds gcov coverage support for Rust device library and binary
modules (including test modules). Support is provided to pass Rust
static library gcno files to CC modules and visa versa.

Additional changes:
 * Begin mutator added for Rust modules.
 * SuffixInList added to android package.
 * CoverageEnabled added to Coverage interface.
 * CoverageFiles added to LinkableLibrary interface.
 * Fix in coverage mutator for non-CC modules which marked the wrong
   variant as the coverage variant.
 * Added coverage libraries to the cc.GatherRequiredDepsForTest.

Bug: 146448203
Test: NATIVE_COVERAGE=true COVERAGE_PATHS='*' m -j <rust_module>
Change-Id: If20728bdde42a1dd544a35a40f0d981b80a5835f
diff --git a/rust/androidmk.go b/rust/androidmk.go
index 0fba739..0e2bea3 100644
--- a/rust/androidmk.go
+++ b/rust/androidmk.go
@@ -46,6 +46,12 @@
 }
 
 func (mod *Module) AndroidMk() android.AndroidMkData {
+	if mod.Properties.HideFromMake {
+		return android.AndroidMkData{
+			Disabled: true,
+		}
+	}
+
 	ret := android.AndroidMkData{
 		OutputFile: mod.outputFile,
 		Include:    "$(BUILD_SYSTEM)/soong_rust_prebuilt.mk",
@@ -84,6 +90,9 @@
 	ret.DistFile = binary.distFile
 	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_SOONG_UNSTRIPPED_BINARY :=", binary.unstrippedOutputFile.String())
+		if binary.coverageOutputZipFile.Valid() {
+			fmt.Fprintln(w, "LOCAL_PREBUILT_COVERAGE_ARCHIVE := "+binary.coverageOutputZipFile.String())
+		}
 	})
 }
 
@@ -124,6 +133,10 @@
 		if !library.rlib() {
 			fmt.Fprintln(w, "LOCAL_SOONG_UNSTRIPPED_BINARY :=", library.unstrippedOutputFile.String())
 		}
+		if library.coverageOutputZipFile.Valid() {
+			fmt.Fprintln(w, "LOCAL_PREBUILT_COVERAGE_ARCHIVE := "+library.coverageOutputZipFile.String())
+		}
+
 	})
 }
 
diff --git a/rust/binary.go b/rust/binary.go
index fda056e..c25ae09 100644
--- a/rust/binary.go
+++ b/rust/binary.go
@@ -35,9 +35,10 @@
 type binaryDecorator struct {
 	*baseCompiler
 
-	Properties           BinaryCompilerProperties
-	distFile             android.OptionalPath
-	unstrippedOutputFile android.Path
+	Properties            BinaryCompilerProperties
+	distFile              android.OptionalPath
+	coverageOutputZipFile android.OptionalPath
+	unstrippedOutputFile  android.Path
 }
 
 var _ compiler = (*binaryDecorator)(nil)
@@ -104,6 +105,10 @@
 		&binary.Properties)
 }
 
+func (binary *binaryDecorator) nativeCoverage() bool {
+	return true
+}
+
 func (binary *binaryDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) android.Path {
 	fileName := binary.getStem(ctx) + ctx.toolchain().ExecutableSuffix()
 
@@ -114,7 +119,21 @@
 
 	flags.RustFlags = append(flags.RustFlags, deps.depFlags...)
 
-	TransformSrcToBinary(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+	outputs := TransformSrcToBinary(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+	binary.coverageFile = outputs.coverageFile
+
+	var coverageFiles android.Paths
+	if outputs.coverageFile != nil {
+		coverageFiles = append(coverageFiles, binary.coverageFile)
+	}
+	if len(deps.coverageFiles) > 0 {
+		coverageFiles = append(coverageFiles, deps.coverageFiles...)
+	}
+	binary.coverageOutputZipFile = TransformCoverageFilesToZip(ctx, coverageFiles, binary.getStem(ctx))
 
 	return outputFile
 }
+
+func (binary *binaryDecorator) coverageOutputZipPath() android.OptionalPath {
+	return binary.coverageOutputZipFile
+}
diff --git a/rust/builder.go b/rust/builder.go
index 2d5e602..fbe0e53 100644
--- a/rust/builder.go
+++ b/rust/builder.go
@@ -18,6 +18,7 @@
 	"strings"
 
 	"github.com/google/blueprint"
+	"github.com/google/blueprint/pathtools"
 
 	"android/soong/android"
 )
@@ -36,44 +37,57 @@
 			Depfile: "$out.d",
 		},
 		"rustcFlags", "linkFlags", "libFlags", "crtBegin", "crtEnd")
+
+	zip = pctx.AndroidStaticRule("zip",
+		blueprint.RuleParams{
+			Command:        "cat $out.rsp | tr ' ' '\\n' | tr -d \\' | sort -u > ${out}.tmp && ${SoongZipCmd} -o ${out} -C $$OUT_DIR -l ${out}.tmp",
+			CommandDeps:    []string{"${SoongZipCmd}"},
+			Rspfile:        "$out.rsp",
+			RspfileContent: "$in",
+		})
 )
 
-func init() {
+type buildOutput struct {
+	outputFile   android.Path
+	coverageFile android.Path
+}
 
+func init() {
+	pctx.HostBinToolVariable("SoongZipCmd", "soong_zip")
 }
 
 func TransformSrcToBinary(ctx android.ModuleContext, mainSrc android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, includeDirs []string) {
+	outputFile android.WritablePath, includeDirs []string) buildOutput {
 	flags.RustFlags = append(flags.RustFlags, "-C lto")
 
-	transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "bin", includeDirs)
+	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "bin", includeDirs)
 }
 
 func TransformSrctoRlib(ctx android.ModuleContext, mainSrc android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, includeDirs []string) {
-	transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "rlib", includeDirs)
+	outputFile android.WritablePath, includeDirs []string) buildOutput {
+	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "rlib", includeDirs)
 }
 
 func TransformSrctoDylib(ctx android.ModuleContext, mainSrc android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, includeDirs []string) {
-	transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "dylib", includeDirs)
+	outputFile android.WritablePath, includeDirs []string) buildOutput {
+	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "dylib", includeDirs)
 }
 
 func TransformSrctoStatic(ctx android.ModuleContext, mainSrc android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, includeDirs []string) {
+	outputFile android.WritablePath, includeDirs []string) buildOutput {
 	flags.RustFlags = append(flags.RustFlags, "-C lto")
-	transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "staticlib", includeDirs)
+	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "staticlib", includeDirs)
 }
 
 func TransformSrctoShared(ctx android.ModuleContext, mainSrc android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, includeDirs []string) {
+	outputFile android.WritablePath, includeDirs []string) buildOutput {
 	flags.RustFlags = append(flags.RustFlags, "-C lto")
-	transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "cdylib", includeDirs)
+	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "cdylib", includeDirs)
 }
 
 func TransformSrctoProcMacro(ctx android.ModuleContext, mainSrc android.Path, deps PathDeps,
-	flags Flags, outputFile android.WritablePath, includeDirs []string) {
-	transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "proc-macro", includeDirs)
+	flags Flags, outputFile android.WritablePath, includeDirs []string) buildOutput {
+	return transformSrctoCrate(ctx, mainSrc, deps, flags, outputFile, "proc-macro", includeDirs)
 }
 
 func rustLibsToPaths(libs RustLibraries) android.Paths {
@@ -85,11 +99,15 @@
 }
 
 func transformSrctoCrate(ctx android.ModuleContext, main android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, crate_type string, includeDirs []string) {
+	outputFile android.WritablePath, crate_type string, includeDirs []string) buildOutput {
 
 	var inputs android.Paths
 	var implicits android.Paths
+	var output buildOutput
 	var libFlags, rustcFlags, linkFlags []string
+	var implicitOutputs android.WritablePaths
+
+	output.outputFile = outputFile
 	crate_name := ctx.(ModuleContext).CrateName()
 	targetTriple := ctx.(ModuleContext).toolchain().RustTriple()
 
@@ -141,12 +159,26 @@
 		implicits = append(implicits, deps.CrtBegin.Path(), deps.CrtEnd.Path())
 	}
 
+	if flags.Coverage {
+		var gcnoFile android.WritablePath
+
+		if outputFile.Ext() != "" {
+			gcnoFile = android.PathForModuleOut(ctx, pathtools.ReplaceExtension(outputFile.Base(), "gcno"))
+		} else {
+			gcnoFile = android.PathForModuleOut(ctx, outputFile.Base()+".gcno")
+		}
+
+		implicitOutputs = append(implicitOutputs, gcnoFile)
+		output.coverageFile = gcnoFile
+	}
+
 	ctx.Build(pctx, android.BuildParams{
-		Rule:        rustc,
-		Description: "rustc " + main.Rel(),
-		Output:      outputFile,
-		Inputs:      inputs,
-		Implicits:   implicits,
+		Rule:            rustc,
+		Description:     "rustc " + main.Rel(),
+		Output:          outputFile,
+		ImplicitOutputs: implicitOutputs,
+		Inputs:          inputs,
+		Implicits:       implicits,
 		Args: map[string]string{
 			"rustcFlags": strings.Join(rustcFlags, " "),
 			"linkFlags":  strings.Join(linkFlags, " "),
@@ -156,4 +188,23 @@
 		},
 	})
 
+	return output
+}
+
+func TransformCoverageFilesToZip(ctx android.ModuleContext,
+	covFiles android.Paths, baseName string) android.OptionalPath {
+	if len(covFiles) > 0 {
+
+		outputFile := android.PathForModuleOut(ctx, baseName+".zip")
+
+		ctx.Build(pctx, android.BuildParams{
+			Rule:        zip,
+			Description: "zip " + outputFile.Base(),
+			Inputs:      covFiles,
+			Output:      outputFile,
+		})
+
+		return android.OptionalPathForPath(outputFile)
+	}
+	return android.OptionalPath{}
 }
diff --git a/rust/compiler.go b/rust/compiler.go
index 7499776..5f098bc 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -110,6 +110,7 @@
 	linkDirs      []string
 	edition       string
 	src           android.Path //rustc takes a single src file
+	coverageFile  android.Path //rustc generates a single gcno file
 
 	// Install related
 	dir      string
@@ -120,6 +121,10 @@
 	location installLocation
 }
 
+func (compiler *baseCompiler) coverageOutputZipPath() android.OptionalPath {
+	panic("baseCompiler does not implement coverageOutputZipPath()")
+}
+
 var _ compiler = (*baseCompiler)(nil)
 
 func (compiler *baseCompiler) inData() bool {
@@ -235,6 +240,10 @@
 		compiler.relativeInstallPath(), compiler.relative)
 }
 
+func (compiler *baseCompiler) nativeCoverage() bool {
+	return false
+}
+
 func (compiler *baseCompiler) install(ctx ModuleContext, file android.Path) {
 	compiler.path = ctx.InstallFile(compiler.installDir(ctx), file.Base(), file)
 }
diff --git a/rust/coverage.go b/rust/coverage.go
new file mode 100644
index 0000000..9be57dc
--- /dev/null
+++ b/rust/coverage.go
@@ -0,0 +1,72 @@
+// Copyright 2020 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 (
+	"github.com/google/blueprint"
+
+	"android/soong/cc"
+)
+
+var CovLibraryName = "libprofile-extras"
+
+type coverage struct {
+	Properties cc.CoverageProperties
+
+	// Whether binaries containing this module need --coverage added to their ldflags
+	linkCoverage bool
+}
+
+func (cov *coverage) props() []interface{} {
+	return []interface{}{&cov.Properties}
+}
+
+func (cov *coverage) deps(ctx DepsContext, deps Deps) Deps {
+	if cov.Properties.NeedCoverageVariant {
+		ctx.AddVariationDependencies([]blueprint.Variation{
+			{Mutator: "link", Variation: "static"},
+		}, cc.CoverageDepTag, CovLibraryName)
+	}
+
+	return deps
+}
+
+func (cov *coverage) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags, PathDeps) {
+
+	if !ctx.DeviceConfig().NativeCoverageEnabled() && !ctx.DeviceConfig().ClangCoverageEnabled() {
+		return flags, deps
+	}
+
+	if cov.Properties.CoverageEnabled {
+		flags.Coverage = true
+		coverage := ctx.GetDirectDepWithTag(CovLibraryName, cc.CoverageDepTag).(cc.LinkableInterface)
+		flags.RustFlags = append(flags.RustFlags,
+			"-Z profile", "-g", "-C opt-level=0", "-C link-dead-code", "-Z no-landing-pads")
+		flags.LinkFlags = append(flags.LinkFlags,
+			"--coverage", "-g", coverage.OutputFile().Path().String(), "-Wl,--wrap,getenv")
+		deps.StaticLibs = append(deps.StaticLibs, coverage.OutputFile().Path())
+	}
+
+	return flags, deps
+}
+
+func (cov *coverage) begin(ctx BaseModuleContext) {
+	if ctx.Host() {
+		// Host coverage not yet supported.
+	} else {
+		// Update useSdk and sdkVersion args if Rust modules become SDK aware.
+		cov.Properties = cc.SetCoverageProperties(ctx, cov.Properties, ctx.nativeCoverage(), false, "")
+	}
+}
diff --git a/rust/coverage_test.go b/rust/coverage_test.go
new file mode 100644
index 0000000..27acad3
--- /dev/null
+++ b/rust/coverage_test.go
@@ -0,0 +1,181 @@
+// Copyright 2020 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 (
+	"strings"
+	"testing"
+
+	"android/soong/android"
+)
+
+// Test that coverage flags are being correctly generated.
+func TestCoverageFlags(t *testing.T) {
+	ctx := testRustCov(t, `
+		rust_library {
+			name: "libfoo_cov",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+		}
+		rust_binary {
+			name: "fizz_cov",
+			srcs: ["foo.rs"],
+		}
+        rust_binary {
+			name: "buzzNoCov",
+			srcs: ["foo.rs"],
+			native_coverage: false,
+		}
+		rust_library {
+			name: "libbar_nocov",
+			srcs: ["foo.rs"],
+			crate_name: "bar",
+			native_coverage: false,
+		}`)
+
+	// Make sure native_coverage: false isn't creating a coverage variant.
+	if android.InList("android_arm64_armv8-a_dylib_cov", ctx.ModuleVariantsForTests("libbar_nocov")) {
+		t.Fatalf("coverage variant created for module 'libbar_nocov' with native coverage disabled")
+	}
+
+	// Just test the dylib variants unless the library coverage logic changes to distinguish between the types.
+	libfooCov := ctx.ModuleForTests("libfoo_cov", "android_arm64_armv8-a_dylib_cov").Rule("rustc")
+	libbarNoCov := ctx.ModuleForTests("libbar_nocov", "android_arm64_armv8-a_dylib").Rule("rustc")
+	fizzCov := ctx.ModuleForTests("fizz_cov", "android_arm64_armv8-a_cov").Rule("rustc")
+	buzzNoCov := ctx.ModuleForTests("buzzNoCov", "android_arm64_armv8-a").Rule("rustc")
+
+	rustcCoverageFlags := []string{"-Z profile", " -g ", "-C opt-level=0", "-C link-dead-code", "-Z no-landing-pads"}
+	for _, flag := range rustcCoverageFlags {
+		missingErrorStr := "missing rustc flag '%s' for '%s' module with coverage enabled; rustcFlags: %#v"
+		containsErrorStr := "contains rustc flag '%s' for '%s' module with coverage disabled; rustcFlags: %#v"
+
+		if !strings.Contains(fizzCov.Args["rustcFlags"], flag) {
+			t.Fatalf(missingErrorStr, flag, "fizz_cov", fizzCov.Args["rustcFlags"])
+		}
+		if !strings.Contains(libfooCov.Args["rustcFlags"], flag) {
+			t.Fatalf(missingErrorStr, flag, "libfoo_cov dylib", libfooCov.Args["rustcFlags"])
+		}
+		if strings.Contains(buzzNoCov.Args["rustcFlags"], flag) {
+			t.Fatalf(containsErrorStr, flag, "buzzNoCov", buzzNoCov.Args["rustcFlags"])
+		}
+		if strings.Contains(libbarNoCov.Args["rustcFlags"], flag) {
+			t.Fatalf(containsErrorStr, flag, "libbar_cov", libbarNoCov.Args["rustcFlags"])
+		}
+	}
+
+	linkCoverageFlags := []string{"--coverage", " -g "}
+	for _, flag := range linkCoverageFlags {
+		missingErrorStr := "missing rust linker flag '%s' for '%s' module with coverage enabled; rustcFlags: %#v"
+		containsErrorStr := "contains rust linker flag '%s' for '%s' module with coverage disabled; rustcFlags: %#v"
+
+		if !strings.Contains(fizzCov.Args["linkFlags"], flag) {
+			t.Fatalf(missingErrorStr, flag, "fizz_cov", fizzCov.Args["linkFlags"])
+		}
+		if !strings.Contains(libfooCov.Args["linkFlags"], flag) {
+			t.Fatalf(missingErrorStr, flag, "libfoo_cov dylib", libfooCov.Args["linkFlags"])
+		}
+		if strings.Contains(buzzNoCov.Args["linkFlags"], flag) {
+			t.Fatalf(containsErrorStr, flag, "buzzNoCov", buzzNoCov.Args["linkFlags"])
+		}
+		if strings.Contains(libbarNoCov.Args["linkFlags"], flag) {
+			t.Fatalf(containsErrorStr, flag, "libbar_cov", libbarNoCov.Args["linkFlags"])
+		}
+	}
+
+}
+
+// Test coverage files are included correctly
+func TestCoverageZip(t *testing.T) {
+	ctx := testRustCov(t, `
+		rust_library {
+			name: "libfoo",
+			srcs: ["foo.rs"],
+			rlibs: ["librlib"],
+			crate_name: "foo",
+		}
+		rust_library_rlib {
+			name: "librlib",
+			srcs: ["foo.rs"],
+			crate_name: "rlib",
+		}
+		rust_binary {
+			name: "fizz",
+			rlibs: ["librlib"],
+			static_libs: ["libfoo"],
+			srcs: ["foo.rs"],
+		}
+		cc_binary {
+			name: "buzz",
+			static_libs: ["libfoo"],
+			srcs: ["foo.c"],
+		}
+		cc_library {
+			name: "libbar",
+			static_libs: ["libfoo"],
+			compile_multilib: "64",
+			srcs: ["foo.c"],
+		}`)
+
+	fizzZipInputs := ctx.ModuleForTests("fizz", "android_arm64_armv8-a_cov").Rule("zip").Inputs.Strings()
+	libfooZipInputs := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_dylib_cov").Rule("zip").Inputs.Strings()
+	buzzZipInputs := ctx.ModuleForTests("buzz", "android_arm64_armv8-a_cov").Rule("zip").Inputs.Strings()
+	libbarZipInputs := ctx.ModuleForTests("libbar", "android_arm64_armv8-a_shared_cov").Rule("zip").Inputs.Strings()
+
+	// Make sure the expected number of input files are included.
+	if len(fizzZipInputs) != 3 {
+		t.Fatalf("expected only 3 coverage inputs for rust 'fizz' binary, got %#v: %#v", len(fizzZipInputs), fizzZipInputs)
+	}
+	if len(libfooZipInputs) != 2 {
+		t.Fatalf("expected only 2 coverage inputs for rust 'libfoo' library, got %#v: %#v", len(libfooZipInputs), libfooZipInputs)
+	}
+	if len(buzzZipInputs) != 2 {
+		t.Fatalf("expected only 2 coverage inputs for cc 'buzz' binary, got %#v: %#v", len(buzzZipInputs), buzzZipInputs)
+	}
+	if len(libbarZipInputs) != 2 {
+		t.Fatalf("expected only 2 coverage inputs for cc 'libbar' library, got %#v: %#v", len(libbarZipInputs), libbarZipInputs)
+	}
+
+	// Make sure the expected inputs are provided to the zip rule.
+	if !android.SuffixInList(fizzZipInputs, "android_arm64_armv8-a_rlib_cov/librlib.gcno") ||
+		!android.SuffixInList(fizzZipInputs, "android_arm64_armv8-a_static_cov/libfoo.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") ||
+		!android.SuffixInList(libfooZipInputs, "android_arm64_armv8-a_dylib_cov/libfoo.dylib.gcno") {
+		t.Fatalf("missing expected coverage files for rust 'fizz' binary: %#v", libfooZipInputs)
+	}
+	if !android.SuffixInList(buzzZipInputs, "android_arm64_armv8-a_cov/obj/foo.gcno") ||
+		!android.SuffixInList(buzzZipInputs, "android_arm64_armv8-a_static_cov/libfoo.gcno") {
+		t.Fatalf("missing expected coverage files for cc 'buzz' binary: %#v", buzzZipInputs)
+	}
+	if !android.SuffixInList(libbarZipInputs, "android_arm64_armv8-a_static_cov/obj/foo.gcno") ||
+		!android.SuffixInList(libbarZipInputs, "android_arm64_armv8-a_static_cov/libfoo.gcno") {
+		t.Fatalf("missing expected coverage files for cc 'libbar' library: %#v", libbarZipInputs)
+	}
+}
+
+func TestCoverageDeps(t *testing.T) {
+	ctx := testRustCov(t, `
+		rust_binary {
+			name: "fizz",
+			srcs: ["foo.rs"],
+		}`)
+
+	fizz := ctx.ModuleForTests("fizz", "android_arm64_armv8-a_cov").Rule("rustc")
+	if !strings.Contains(fizz.Args["linkFlags"], "libprofile-extras.a") {
+		t.Fatalf("missing expected coverage 'libprofile-extras' dependency in linkFlags: %#v", fizz.Args["linkFlags"])
+	}
+}
diff --git a/rust/library.go b/rust/library.go
index 87e816d..8aa033c 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -75,11 +75,12 @@
 type libraryDecorator struct {
 	*baseCompiler
 
-	Properties           LibraryCompilerProperties
-	MutatedProperties    LibraryMutatedProperties
-	distFile             android.OptionalPath
-	unstrippedOutputFile android.Path
-	includeDirs          android.Paths
+	Properties            LibraryCompilerProperties
+	MutatedProperties     LibraryMutatedProperties
+	distFile              android.OptionalPath
+	coverageOutputZipFile android.OptionalPath
+	unstrippedOutputFile  android.Path
+	includeDirs           android.Paths
 }
 
 type libraryInterface interface {
@@ -107,6 +108,10 @@
 	BuildOnlyShared()
 }
 
+func (library *libraryDecorator) nativeCoverage() bool {
+	return true
+}
+
 func (library *libraryDecorator) exportedDirs() []string {
 	return library.linkDirs
 }
@@ -351,24 +356,37 @@
 		fileName := library.getStem(ctx) + ctx.toolchain().RlibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
-		TransformSrctoRlib(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		outputs := TransformSrctoRlib(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		library.coverageFile = outputs.coverageFile
 	} else if library.dylib() {
 		fileName := library.getStem(ctx) + ctx.toolchain().DylibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
-		TransformSrctoDylib(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		outputs := TransformSrctoDylib(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		library.coverageFile = outputs.coverageFile
 	} else if library.static() {
 		fileName := library.getStem(ctx) + ctx.toolchain().StaticLibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
-		TransformSrctoStatic(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		outputs := TransformSrctoStatic(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		library.coverageFile = outputs.coverageFile
 	} else if library.shared() {
 		fileName := library.getStem(ctx) + ctx.toolchain().SharedLibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
-		TransformSrctoShared(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		outputs := TransformSrctoShared(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
+		library.coverageFile = outputs.coverageFile
 	}
 
+	var coverageFiles android.Paths
+	if library.coverageFile != nil {
+		coverageFiles = append(coverageFiles, library.coverageFile)
+	}
+	if len(deps.coverageFiles) > 0 {
+		coverageFiles = append(coverageFiles, deps.coverageFiles...)
+	}
+	library.coverageOutputZipFile = TransformCoverageFilesToZip(ctx, coverageFiles, library.getStem(ctx))
+
 	if library.rlib() || library.dylib() {
 		library.reexportDirs(deps.linkDirs...)
 		library.reexportDepFlags(deps.depFlags...)
diff --git a/rust/prebuilt.go b/rust/prebuilt.go
index 45bef9e..1d97650 100644
--- a/rust/prebuilt.go
+++ b/rust/prebuilt.go
@@ -69,3 +69,7 @@
 	deps = prebuilt.baseCompiler.compilerDeps(ctx, deps)
 	return deps
 }
+
+func (prebuilt *prebuiltLibraryDecorator) nativeCoverage() bool {
+	return false
+}
diff --git a/rust/rust.go b/rust/rust.go
index 5cc8845..8cf2e6d 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -40,6 +40,7 @@
 	android.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
 		ctx.BottomUp("rust_libraries", LibraryMutator).Parallel()
 		ctx.BottomUp("rust_unit_tests", TestPerSrcMutator).Parallel()
+		ctx.BottomUp("rust_begin", BeginMutator).Parallel()
 	})
 	pctx.Import("android/soong/rust/config")
 }
@@ -51,6 +52,7 @@
 	LinkFlags       []string      // Flags that apply to linker
 	RustFlagsDeps   android.Paths // Files depended on by compiler flags
 	Toolchain       config.Toolchain
+	Coverage        bool
 }
 
 type BaseProperties struct {
@@ -60,6 +62,8 @@
 	AndroidMkSharedLibs    []string
 	AndroidMkStaticLibs    []string
 	SubName                string `blueprint:"mutated"`
+	PreventInstall         bool
+	HideFromMake           bool
 }
 
 type Module struct {
@@ -72,6 +76,7 @@
 	multilib android.Multilib
 
 	compiler         compiler
+	coverage         *coverage
 	cachedToolchain  config.Toolchain
 	subAndroidMkOnce map[subAndroidMkProvider]bool
 	outputFile       android.OptionalPath
@@ -224,6 +229,8 @@
 	depFlags   []string
 	//ReexportedDeps android.Paths
 
+	coverageFiles android.Paths
+
 	CrtBegin android.OptionalPath
 	CrtEnd   android.OptionalPath
 }
@@ -245,6 +252,34 @@
 	inData() bool
 	install(ctx ModuleContext, path android.Path)
 	relativeInstallPath() string
+
+	nativeCoverage() bool
+}
+
+func (mod *Module) isCoverageVariant() bool {
+	return mod.coverage.Properties.IsCoverageVariant
+}
+
+var _ cc.Coverage = (*Module)(nil)
+
+func (mod *Module) IsNativeCoverageNeeded(ctx android.BaseModuleContext) bool {
+	return mod.coverage != nil && mod.coverage.Properties.NeedCoverageVariant
+}
+
+func (mod *Module) PreventInstall() {
+	mod.Properties.PreventInstall = true
+}
+
+func (mod *Module) HideFromMake() {
+	mod.Properties.HideFromMake = true
+}
+
+func (mod *Module) MarkAsCoverageVariant(coverage bool) {
+	mod.coverage.Properties.IsCoverageVariant = coverage
+}
+
+func (mod *Module) EnableCoverageIfNeeded() {
+	mod.coverage.Properties.CoverageEnabled = mod.coverage.Properties.NeedCoverageBuild
 }
 
 func defaultsFactory() android.Module {
@@ -268,6 +303,7 @@
 		&ProcMacroCompilerProperties{},
 		&PrebuiltProperties{},
 		&TestProperties{},
+		&cc.CoverageProperties{},
 	)
 
 	android.InitDefaultsModule(module)
@@ -395,6 +431,18 @@
 	return false
 }
 
+func (mod *Module) CoverageFiles() android.Paths {
+	if mod.compiler != nil {
+		if library, ok := mod.compiler.(*libraryDecorator); ok {
+			if library.coverageFile != nil {
+				return android.Paths{library.coverageFile}
+			}
+			return android.Paths{}
+		}
+	}
+	panic(fmt.Errorf("CoverageFiles called on non-library module: %q", mod.BaseModuleName()))
+}
+
 var _ cc.LinkableInterface = (*Module)(nil)
 
 func (mod *Module) Init() android.Module {
@@ -403,6 +451,10 @@
 	if mod.compiler != nil {
 		mod.AddProperties(mod.compiler.compilerProps()...)
 	}
+	if mod.coverage != nil {
+		mod.AddProperties(mod.coverage.props()...)
+	}
+
 	android.InitAndroidArchModule(mod, mod.hod, mod.multilib)
 
 	android.InitDefaultableModule(mod)
@@ -432,6 +484,7 @@
 }
 func newModule(hod android.HostOrDeviceSupported, multilib android.Multilib) *Module {
 	module := newBaseModule(hod, multilib)
+	module.coverage = &coverage{}
 	return module
 }
 
@@ -454,6 +507,7 @@
 	toolchain() config.Toolchain
 	baseModuleName() string
 	CrateName() string
+	nativeCoverage() bool
 }
 
 type depsContext struct {
@@ -466,6 +520,14 @@
 	moduleContextImpl
 }
 
+func (ctx *moduleContextImpl) nativeCoverage() bool {
+	return ctx.mod.nativeCoverage()
+}
+
+func (mod *Module) nativeCoverage() bool {
+	return mod.compiler != nil && mod.compiler.nativeCoverage()
+}
+
 type moduleContextImpl struct {
 	mod *Module
 	ctx BaseModuleContext
@@ -508,9 +570,17 @@
 
 	if mod.compiler != nil {
 		flags = mod.compiler.compilerFlags(ctx, flags)
+	}
+	if mod.coverage != nil {
+		flags, deps = mod.coverage.flags(ctx, flags, deps)
+	}
+
+	if mod.compiler != nil {
 		outputFile := mod.compiler.compile(ctx, flags, deps)
 		mod.outputFile = android.OptionalPathForPath(outputFile)
-		mod.compiler.install(ctx, mod.outputFile.Path())
+		if !mod.Properties.PreventInstall {
+			mod.compiler.install(ctx, mod.outputFile.Path())
+		}
 	}
 }
 
@@ -521,6 +591,10 @@
 		deps = mod.compiler.compilerDeps(ctx, deps)
 	}
 
+	if mod.coverage != nil {
+		deps = mod.coverage.deps(ctx, deps)
+	}
+
 	deps.Rlibs = android.LastUniqueStrings(deps.Rlibs)
 	deps.Dylibs = android.LastUniqueStrings(deps.Dylibs)
 	deps.ProcMacros = android.LastUniqueStrings(deps.ProcMacros)
@@ -553,6 +627,12 @@
 	testPerSrcDepTag = dependencyTag{name: "rust_unit_tests"}
 )
 
+func (mod *Module) begin(ctx BaseModuleContext) {
+	if mod.coverage != nil {
+		mod.coverage.begin(ctx)
+	}
+}
+
 func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 	var depPaths PathDeps
 
@@ -588,6 +668,7 @@
 					ctx.ModuleErrorf("mod %q not an rlib library", depName)
 					return
 				}
+				depPaths.coverageFiles = append(depPaths.coverageFiles, rustDep.CoverageFiles()...)
 				directRlibDeps = append(directRlibDeps, rustDep)
 				mod.Properties.AndroidMkRlibs = append(mod.Properties.AndroidMkRlibs, depName)
 			case procMacroDepTag:
@@ -642,6 +723,7 @@
 				depFlag = "-lstatic=" + libName
 				depPaths.linkDirs = append(depPaths.linkDirs, linkPath)
 				depPaths.depFlags = append(depPaths.depFlags, depFlag)
+				depPaths.coverageFiles = append(depPaths.coverageFiles, ccDep.CoverageFiles()...)
 				directStaticLibDeps = append(directStaticLibDeps, ccDep)
 				mod.Properties.AndroidMkStaticLibs = append(mod.Properties.AndroidMkStaticLibs, depName)
 			case cc.SharedDepTag:
@@ -772,6 +854,29 @@
 	actx.AddFarVariationDependencies(ctx.Config().BuildOSTarget.Variations(), procMacroDepTag, deps.ProcMacros...)
 }
 
+func BeginMutator(ctx android.BottomUpMutatorContext) {
+	if mod, ok := ctx.Module().(*Module); ok && mod.Enabled() {
+		mod.beginMutator(ctx)
+	}
+}
+
+type baseModuleContext struct {
+	android.BaseModuleContext
+	moduleContextImpl
+}
+
+func (mod *Module) beginMutator(actx android.BottomUpMutatorContext) {
+	ctx := &baseModuleContext{
+		BaseModuleContext: actx,
+		moduleContextImpl: moduleContextImpl{
+			mod: mod,
+		},
+	}
+	ctx.ctx = ctx
+
+	mod.begin(ctx)
+}
+
 func (mod *Module) Name() string {
 	name := mod.ModuleBase.Name()
 	if p, ok := mod.compiler.(interface {
diff --git a/rust/rust_test.go b/rust/rust_test.go
index 32eddc1..d658ee2 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -21,6 +21,8 @@
 	"strings"
 	"testing"
 
+	"github.com/google/blueprint/proptools"
+
 	"android/soong/android"
 	"android/soong/cc"
 )
@@ -57,6 +59,7 @@
 
 	fs := map[string][]byte{
 		"foo.rs":     nil,
+		"foo.c":      nil,
 		"src/bar.rs": nil,
 		"liby.so":    nil,
 		"libz.so":    nil,
@@ -68,6 +71,14 @@
 }
 
 func testRust(t *testing.T, bp string) *android.TestContext {
+	return testRustContext(t, bp, false)
+}
+
+func testRustCov(t *testing.T, bp string) *android.TestContext {
+	return testRustContext(t, bp, true)
+}
+
+func testRustContext(t *testing.T, bp string, coverage bool) *android.TestContext {
 	// TODO (b/140435149)
 	if runtime.GOOS != "linux" {
 		t.Skip("Only the Linux toolchain is supported for Rust")
@@ -76,6 +87,11 @@
 	t.Helper()
 	config := testConfig(bp)
 
+	if coverage {
+		config.TestProductVariables.Native_coverage = proptools.BoolPtr(true)
+		config.TestProductVariables.CoveragePaths = []string{"*"}
+	}
+
 	t.Helper()
 	ctx := CreateTestContext()
 	ctx.Register(config)
diff --git a/rust/test.go b/rust/test.go
index 04f844c..94568c1 100644
--- a/rust/test.go
+++ b/rust/test.go
@@ -50,6 +50,10 @@
 	testConfig android.Path
 }
 
+func (test *testDecorator) nativeCoverage() bool {
+	return true
+}
+
 func NewRustTest(hod android.HostOrDeviceSupported) (*Module, *testDecorator) {
 	module := newModule(hod, android.MultilibFirst)
 
diff --git a/rust/testing.go b/rust/testing.go
index aad4ffe..09008a8 100644
--- a/rust/testing.go
+++ b/rust/testing.go
@@ -98,6 +98,7 @@
 		// rust mutators
 		ctx.BottomUp("rust_libraries", LibraryMutator).Parallel()
 		ctx.BottomUp("rust_unit_tests", TestPerSrcMutator).Parallel()
+		ctx.BottomUp("rust_begin", BeginMutator).Parallel()
 	})
 
 	return ctx