Split Rust crate builds into compile and link phases.

Teach rustc to generate object files instead of a linked executable
for binary and shared library crates. This lets us skip the lengthy
Rust compilation phase when only the C++ dependencies of these crates
have changed.

This works using a Python script that replaces the linker invoked by
rustc and converts the linker command line into a rspfile that can be
used during the link phase. The script makes certain assumptions about
how rustc invokes the linker, but since we control the version of Rust
we use, we can update the script if those assumptions ever break. I've
asked the Rust developers about adding an official way to do this so
hopefully we won't need to rely on this hack in the future.

The rustc rule for Kythe has been altered to pass linker=true, somewhat
consistent with the main rustc rule, which now doesn't invoke the actual
linker either. `m xref_rust` still succeeds, but hopefully we can find
someone who knows more about the rest of the Kythe pipeline who can let
us know whether it should still work. Otherwise, let's use this CL as
an opportunity to find out whether the rest of the pipeline is happy
with linker=true, since otherwise we will find it hard to maintain the
Kythe rule in the future.

Change-Id: Ifb9c8689c1bd78c0afcf6fdfd111140d20377536

apex/apex_test.go

@@ -1001,7 +1001,7 @@ func TestApexWithStubs(t *testing.T) {
 	// Ensure that stub dependency from a rust module is not included
 	ensureNotContains(t, copyCmds, "image.apex/lib64/libfoo.shared_from_rust.so")
 	// The rust module is linked to the stub cc library
-	rustDeps := ctx.ModuleForTests("foo.rust", "android_arm64_armv8-a_apex10000").Rule("rustc").Args["linkFlags"]
+	rustDeps := ctx.ModuleForTests("foo.rust", "android_arm64_armv8-a_apex10000").Rule("rustLink").Args["linkFlags"]
 	ensureContains(t, rustDeps, "libfoo.shared_from_rust/android_arm64_armv8-a_shared_current/libfoo.shared_from_rust.so")
 	ensureNotContains(t, rustDeps, "libfoo.shared_from_rust/android_arm64_armv8-a_shared/libfoo.shared_from_rust.so")
 
@@ -1077,7 +1077,7 @@ func TestApexCanUsePrivateApis(t *testing.T) {
 	mylibLdFlags := ctx.ModuleForTests("mylib", "android_arm64_armv8-a_shared_apex10000").Rule("ld").Args["libFlags"]
 	ensureNotContains(t, mylibLdFlags, "mylib2/android_arm64_armv8-a_shared_current/mylib2.so")
 	ensureContains(t, mylibLdFlags, "mylib2/android_arm64_armv8-a_shared/mylib2.so")
-	rustDeps := ctx.ModuleForTests("foo.rust", "android_arm64_armv8-a_apex10000").Rule("rustc").Args["linkFlags"]
+	rustDeps := ctx.ModuleForTests("foo.rust", "android_arm64_armv8-a_apex10000").Rule("rustLink").Args["linkFlags"]
 	ensureNotContains(t, rustDeps, "libfoo.shared_from_rust/android_arm64_armv8-a_shared_current/libfoo.shared_from_rust.so")
 	ensureContains(t, rustDeps, "libfoo.shared_from_rust/android_arm64_armv8-a_shared/libfoo.shared_from_rust.so")
 }

rust/binary.go

@@ -72,11 +72,14 @@ func NewRustBinary(hod android.HostOrDeviceSupported) (*Module, *binaryDecorator
 func (binary *binaryDecorator) compilerFlags(ctx ModuleContext, flags Flags) Flags {
 	flags = binary.baseCompiler.compilerFlags(ctx, flags)
 
+	if ctx.Os().Linux() {
+		flags.LinkFlags = append(flags.LinkFlags, "-Wl,--gc-sections")
+	}
+
 	if ctx.toolchain().Bionic() {
 		// no-undefined-version breaks dylib compilation since __rust_*alloc* functions aren't defined,
 		// but we can apply this to binaries.
 		flags.LinkFlags = append(flags.LinkFlags,
-			"-Wl,--gc-sections",
 			"-Wl,-z,nocopyreloc",
 			"-Wl,--no-undefined-version")
 
@@ -136,7 +139,7 @@ func (binary *binaryDecorator) compile(ctx ModuleContext, flags Flags, deps Path
 
 	flags.RustFlags = append(flags.RustFlags, deps.depFlags...)
 	flags.LinkFlags = append(flags.LinkFlags, deps.depLinkFlags...)
-	flags.LinkFlags = append(flags.LinkFlags, deps.linkObjects...)
+	flags.LinkFlags = append(flags.LinkFlags, deps.linkObjects.Strings()...)
 
 	if binary.stripper.NeedsStrip(ctx) {
 		strippedOutputFile := outputFile

rust/binary_test.go

@@ -123,7 +123,7 @@ func TestBootstrap(t *testing.T) {
 			bootstrap: true,
 		}`)
 
-	foo := ctx.ModuleForTests("foo", "android_arm64_armv8-a").Rule("rustc")
+	foo := ctx.ModuleForTests("foo", "android_arm64_armv8-a").Rule("rustLink")
 
 	flag := "-Wl,-dynamic-linker,/system/bin/bootstrap/linker64"
 	if !strings.Contains(foo.Args["linkFlags"], flag) {
@@ -140,10 +140,11 @@ func TestStaticBinaryFlags(t *testing.T) {
 		}`)
 
 	fizzOut := ctx.ModuleForTests("fizz", "android_arm64_armv8-a").Rule("rustc")
+	fizzOutLink := ctx.ModuleForTests("fizz", "android_arm64_armv8-a").Rule("rustLink")
 	fizzMod := ctx.ModuleForTests("fizz", "android_arm64_armv8-a").Module().(*Module)
 
 	flags := fizzOut.Args["rustcFlags"]
-	linkFlags := fizzOut.Args["linkFlags"]
+	linkFlags := fizzOutLink.Args["linkFlags"]
 	if !strings.Contains(flags, "-C relocation-model=static") {
 		t.Errorf("static binary missing '-C relocation-model=static' in rustcFlags, found: %#v", flags)
 	}
@@ -173,7 +174,7 @@ func TestLinkObjects(t *testing.T) {
 			name: "libfoo",
 		}`)
 
-	fizzBuzz := ctx.ModuleForTests("fizz-buzz", "android_arm64_armv8-a").Rule("rustc")
+	fizzBuzz := ctx.ModuleForTests("fizz-buzz", "android_arm64_armv8-a").Rule("rustLink")
 	linkFlags := fizzBuzz.Args["linkFlags"]
 	if !strings.Contains(linkFlags, "/libfoo.so") {
 		t.Errorf("missing shared dependency 'libfoo.so' in linkFlags: %#v", linkFlags)

rust/builder.go

@@ -26,14 +26,14 @@ import (
 
 var (
 	_     = pctx.SourcePathVariable("rustcCmd", "${config.RustBin}/rustc")
+	_     = pctx.SourcePathVariable("mkcraterspCmd", "build/soong/scripts/mkcratersp.py")
 	rustc = pctx.AndroidStaticRule("rustc",
 		blueprint.RuleParams{
 			Command: "$envVars $rustcCmd " +
-				"-C linker=${config.RustLinker} " +
+				"-C linker=$mkcraterspCmd " +
-				"-C link-args=\"${crtBegin} ${config.RustLinkerArgs} ${linkFlags} ${crtEnd}\" " +
 				"--emit link -o $out --emit dep-info=$out.d.raw $in ${libFlags} $rustcFlags" +
 				" && grep \"^$out:\" $out.d.raw > $out.d",
-			CommandDeps: []string{"$rustcCmd"},
+			CommandDeps: []string{"$rustcCmd", "$mkcraterspCmd"},
 			// Rustc deps-info writes out make compatible dep files: https://github.com/rust-lang/rust/issues/7633
 			// Rustc emits unneeded dependency lines for the .d and input .rs files.
 			// Those extra lines cause ninja warning:
@@ -42,7 +42,12 @@ var (
 			Deps:    blueprint.DepsGCC,
 			Depfile: "$out.d",
 		},
-		"rustcFlags", "linkFlags", "libFlags", "crtBegin", "crtEnd", "envVars")
+		"rustcFlags", "libFlags", "envVars")
+	rustLink = pctx.AndroidStaticRule("rustLink",
+		blueprint.RuleParams{
+			Command: "${config.RustLinker} -o $out ${crtBegin} ${config.RustLinkerArgs} @$in ${linkFlags} ${crtEnd}",
+		},
+		"linkFlags", "crtBegin", "crtEnd")
 
 	_       = pctx.SourcePathVariable("rustdocCmd", "${config.RustBin}/rustdoc")
 	rustdoc = pctx.AndroidStaticRule("rustdoc",
@@ -101,14 +106,13 @@ var (
 				`KYTHE_CANONICALIZE_VNAME_PATHS=prefer-relative ` +
 				`$rustExtractor $envVars ` +
 				`$rustcCmd ` +
-				`-C linker=${config.RustLinker} ` +
+				`-C linker=true ` +
-				`-C link-args="${crtBegin} ${config.RustLinkerArgs} ${linkFlags} ${crtEnd}" ` +
 				`$in ${libFlags} $rustcFlags`,
 			CommandDeps:    []string{"$rustExtractor", "$kytheVnames"},
 			Rspfile:        "${out}.rsp",
 			RspfileContent: "$in",
 		},
-		"rustcFlags", "linkFlags", "libFlags", "crtBegin", "crtEnd", "envVars")
+		"rustcFlags", "libFlags", "envVars")
 )
 
 type buildOutput struct {
@@ -220,11 +224,9 @@ func transformSrctoCrate(ctx ModuleContext, main android.Path, deps PathDeps, fl
 	outputFile android.WritablePath, crateType string) buildOutput {
 
 	var inputs android.Paths
-	var implicits android.Paths
+	var implicits, linkImplicits, linkOrderOnly android.Paths
-	var orderOnly android.Paths
 	var output buildOutput
 	var rustcFlags, linkFlags []string
-	var implicitOutputs android.WritablePaths
 
 	output.outputFile = outputFile
 	crateName := ctx.RustModule().CrateName()
@@ -281,15 +283,15 @@ func transformSrctoCrate(ctx ModuleContext, main android.Path, deps PathDeps, fl
 	implicits = append(implicits, rustLibsToPaths(deps.RLibs)...)
 	implicits = append(implicits, rustLibsToPaths(deps.DyLibs)...)
 	implicits = append(implicits, rustLibsToPaths(deps.ProcMacros)...)
-	implicits = append(implicits, deps.StaticLibs...)
-	implicits = append(implicits, deps.SharedLibDeps...)
-	implicits = append(implicits, deps.srcProviderFiles...)
 	implicits = append(implicits, deps.AfdoProfiles...)
+	implicits = append(implicits, deps.srcProviderFiles...)
+	implicits = append(implicits, deps.WholeStaticLibs...)
 
-	implicits = append(implicits, deps.CrtBegin...)
+	linkImplicits = append(linkImplicits, deps.LibDeps...)
-	implicits = append(implicits, deps.CrtEnd...)
+	linkImplicits = append(linkImplicits, deps.CrtBegin...)
+	linkImplicits = append(linkImplicits, deps.CrtEnd...)
 
-	orderOnly = append(orderOnly, deps.SharedLibs...)
+	linkOrderOnly = append(linkOrderOnly, deps.linkObjects...)
 
 	if len(deps.SrcDeps) > 0 {
 		moduleGenDir := ctx.RustModule().compiler.CargoOutDir()
@@ -328,16 +330,16 @@ func transformSrctoCrate(ctx ModuleContext, main android.Path, deps PathDeps, fl
 		}
 	}
 
+	envVars = append(envVars, "AR=${cc_config.ClangBin}/llvm-ar")
+
 	if flags.Clippy {
 		clippyFile := android.PathForModuleOut(ctx, outputFile.Base()+".clippy")
 		ctx.Build(pctx, android.BuildParams{
-			Rule:            clippyDriver,
+			Rule:        clippyDriver,
-			Description:     "clippy " + main.Rel(),
+			Description: "clippy " + main.Rel(),
-			Output:          clippyFile,
+			Output:      clippyFile,
-			ImplicitOutputs: nil,
+			Inputs:      inputs,
-			Inputs:          inputs,
+			Implicits:   implicits,
-			Implicits:       implicits,
-			OrderOnly:       orderOnly,
 			Args: map[string]string{
 				"rustcFlags":  strings.Join(rustcFlags, " "),
 				"libFlags":    strings.Join(libFlags, " "),
@@ -349,24 +351,41 @@ func transformSrctoCrate(ctx ModuleContext, main android.Path, deps PathDeps, fl
 		implicits = append(implicits, clippyFile)
 	}
 
+	rustcOutputFile := outputFile
+	usesLinker := crateType == "bin" || crateType == "dylib" || crateType == "cdylib" || crateType == "proc-macro"
+	if usesLinker {
+		rustcOutputFile = android.PathForModuleOut(ctx, outputFile.Base()+".rsp")
+	}
+
 	ctx.Build(pctx, android.BuildParams{
-		Rule:            rustc,
+		Rule:        rustc,
-		Description:     "rustc " + main.Rel(),
+		Description: "rustc " + main.Rel(),
-		Output:          outputFile,
+		Output:      rustcOutputFile,
-		ImplicitOutputs: implicitOutputs,
+		Inputs:      inputs,
-		Inputs:          inputs,
+		Implicits:   implicits,
-		Implicits:       implicits,
-		OrderOnly:       orderOnly,
 		Args: map[string]string{
 			"rustcFlags": strings.Join(rustcFlags, " "),
-			"linkFlags":  strings.Join(linkFlags, " "),
 			"libFlags":   strings.Join(libFlags, " "),
-			"crtBegin":   strings.Join(deps.CrtBegin.Strings(), " "),
-			"crtEnd":     strings.Join(deps.CrtEnd.Strings(), " "),
 			"envVars":    strings.Join(envVars, " "),
 		},
 	})
 
+	if usesLinker {
+		ctx.Build(pctx, android.BuildParams{
+			Rule:        rustLink,
+			Description: "rustLink " + main.Rel(),
+			Output:      outputFile,
+			Inputs:      android.Paths{rustcOutputFile},
+			Implicits:   linkImplicits,
+			OrderOnly:   linkOrderOnly,
+			Args: map[string]string{
+				"linkFlags": strings.Join(linkFlags, " "),
+				"crtBegin":  strings.Join(deps.CrtBegin.Strings(), " "),
+				"crtEnd":    strings.Join(deps.CrtEnd.Strings(), " "),
+			},
+		})
+	}
+
 	if flags.EmitXrefs {
 		kytheFile := android.PathForModuleOut(ctx, outputFile.Base()+".kzip")
 		ctx.Build(pctx, android.BuildParams{
@@ -375,13 +394,9 @@ func transformSrctoCrate(ctx ModuleContext, main android.Path, deps PathDeps, fl
 			Output:      kytheFile,
 			Inputs:      inputs,
 			Implicits:   implicits,
-			OrderOnly:   orderOnly,
 			Args: map[string]string{
 				"rustcFlags": strings.Join(rustcFlags, " "),
-				"linkFlags":  strings.Join(linkFlags, " "),
 				"libFlags":   strings.Join(libFlags, " "),
-				"crtBegin":   strings.Join(deps.CrtBegin.Strings(), " "),
-				"crtEnd":     strings.Join(deps.CrtEnd.Strings(), " "),
 				"envVars":    strings.Join(envVars, " "),
 			},
 		})

rust/coverage.go

@@ -65,7 +65,7 @@ func (cov *coverage) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags
 			"-C instrument-coverage", "-g")
 		flags.LinkFlags = append(flags.LinkFlags,
 			profileInstrFlag, "-g", coverage.OutputFile().Path().String(), "-Wl,--wrap,open")
-		deps.StaticLibs = append(deps.StaticLibs, coverage.OutputFile().Path())
+		deps.LibDeps = append(deps.LibDeps, coverage.OutputFile().Path())
 
 		// no_std modules are missing libprofiler_builtins which provides coverage, so we need to add it as a dependency.
 		if rustModule, ok := ctx.Module().(*Module); ok && rustModule.compiler.noStdlibs() {

rust/coverage_test.go

@@ -55,6 +55,10 @@ func TestCoverageFlags(t *testing.T) {
 	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")
+	libfooCovLink := ctx.ModuleForTests("libfoo_cov", "android_arm64_armv8-a_dylib_cov").Rule("rustLink")
+	libbarNoCovLink := ctx.ModuleForTests("libbar_nocov", "android_arm64_armv8-a_dylib").Rule("rustLink")
+	fizzCovLink := ctx.ModuleForTests("fizz_cov", "android_arm64_armv8-a_cov").Rule("rustLink")
+	buzzNoCovLink := ctx.ModuleForTests("buzzNoCov", "android_arm64_armv8-a").Rule("rustLink")
 
 	rustcCoverageFlags := []string{"-C instrument-coverage", " -g "}
 	for _, flag := range rustcCoverageFlags {
@@ -80,17 +84,17 @@ func TestCoverageFlags(t *testing.T) {
 		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) {
+		if !strings.Contains(fizzCovLink.Args["linkFlags"], flag) {
-			t.Fatalf(missingErrorStr, flag, "fizz_cov", fizzCov.Args["linkFlags"])
+			t.Fatalf(missingErrorStr, flag, "fizz_cov", fizzCovLink.Args["linkFlags"])
 		}
-		if !strings.Contains(libfooCov.Args["linkFlags"], flag) {
+		if !strings.Contains(libfooCovLink.Args["linkFlags"], flag) {
-			t.Fatalf(missingErrorStr, flag, "libfoo_cov dylib", libfooCov.Args["linkFlags"])
+			t.Fatalf(missingErrorStr, flag, "libfoo_cov dylib", libfooCovLink.Args["linkFlags"])
 		}
-		if strings.Contains(buzzNoCov.Args["linkFlags"], flag) {
+		if strings.Contains(buzzNoCovLink.Args["linkFlags"], flag) {
-			t.Fatalf(containsErrorStr, flag, "buzzNoCov", buzzNoCov.Args["linkFlags"])
+			t.Fatalf(containsErrorStr, flag, "buzzNoCov", buzzNoCovLink.Args["linkFlags"])
 		}
-		if strings.Contains(libbarNoCov.Args["linkFlags"], flag) {
+		if strings.Contains(libbarNoCovLink.Args["linkFlags"], flag) {
-			t.Fatalf(containsErrorStr, flag, "libbar_cov", libbarNoCov.Args["linkFlags"])
+			t.Fatalf(containsErrorStr, flag, "libbar_cov", libbarNoCovLink.Args["linkFlags"])
 		}
 	}
 
@@ -103,7 +107,7 @@ func TestCoverageDeps(t *testing.T) {
 			srcs: ["foo.rs"],
 		}`)
 
-	fizz := ctx.ModuleForTests("fizz", "android_arm64_armv8-a_cov").Rule("rustc")
+	fizz := ctx.ModuleForTests("fizz", "android_arm64_armv8-a_cov").Rule("rustLink")
 	if !strings.Contains(fizz.Args["linkFlags"], "libprofile-clang-extras.a") {
 		t.Fatalf("missing expected coverage 'libprofile-clang-extras' dependency in linkFlags: %#v", fizz.Args["linkFlags"])
 	}

rust/library.go

@@ -520,7 +520,7 @@ func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps Pa
 
 	flags.RustFlags = append(flags.RustFlags, deps.depFlags...)
 	flags.LinkFlags = append(flags.LinkFlags, deps.depLinkFlags...)
-	flags.LinkFlags = append(flags.LinkFlags, deps.linkObjects...)
+	flags.LinkFlags = append(flags.LinkFlags, deps.linkObjects.Strings()...)
 
 	if library.dylib() {
 		// We need prefer-dynamic for now to avoid linking in the static stdlib. See:
@@ -543,6 +543,7 @@ func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps Pa
 	if library.rlib() || library.dylib() {
 		library.flagExporter.exportLinkDirs(deps.linkDirs...)
 		library.flagExporter.exportLinkObjects(deps.linkObjects...)
+		library.flagExporter.exportLibDeps(deps.LibDeps...)
 	}
 
 	if library.static() || library.shared() {

rust/library_test.go

@@ -148,7 +148,7 @@ func TestSharedLibrary(t *testing.T) {
 
 	libfoo := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_shared")
 
-	libfooOutput := libfoo.Rule("rustc")
+	libfooOutput := libfoo.Rule("rustLink")
 	if !strings.Contains(libfooOutput.Args["linkFlags"], "-Wl,-soname=libfoo.so") {
 		t.Errorf("missing expected -Wl,-soname linker flag for libfoo shared lib, linkFlags: %#v",
 			libfooOutput.Args["linkFlags"])

rust/rust.go

@@ -420,13 +420,12 @@ type Deps struct {
 }
 
 type PathDeps struct {
-	DyLibs        RustLibraries
+	DyLibs          RustLibraries
-	RLibs         RustLibraries
+	RLibs           RustLibraries
-	SharedLibs    android.Paths
+	LibDeps         android.Paths
-	SharedLibDeps android.Paths
+	WholeStaticLibs android.Paths
-	StaticLibs    android.Paths
+	ProcMacros      RustLibraries
-	ProcMacros    RustLibraries
+	AfdoProfiles    android.Paths
-	AfdoProfiles  android.Paths
 
 	// depFlags and depLinkFlags are rustc and linker (clang) flags.
 	depFlags     []string
@@ -435,7 +434,7 @@ type PathDeps struct {
 	// linkDirs are link paths passed via -L to rustc. linkObjects are objects passed directly to the linker.
 	// Both of these are exported and propagate to dependencies.
 	linkDirs    []string
-	linkObjects []string
+	linkObjects android.Paths
 
 	// Used by bindgen modules which call clang
 	depClangFlags         []string
@@ -498,7 +497,7 @@ type compiler interface {
 
 type exportedFlagsProducer interface {
 	exportLinkDirs(...string)
-	exportLinkObjects(...string)
+	exportLinkObjects(...android.Path)
 }
 
 type xref interface {
@@ -507,21 +506,27 @@ type xref interface {
 
 type flagExporter struct {
 	linkDirs    []string
-	linkObjects []string
+	linkObjects android.Paths
+	libDeps     android.Paths
 }
 
 func (flagExporter *flagExporter) exportLinkDirs(dirs ...string) {
 	flagExporter.linkDirs = android.FirstUniqueStrings(append(flagExporter.linkDirs, dirs...))
 }
 
-func (flagExporter *flagExporter) exportLinkObjects(flags ...string) {
+func (flagExporter *flagExporter) exportLinkObjects(flags ...android.Path) {
-	flagExporter.linkObjects = android.FirstUniqueStrings(append(flagExporter.linkObjects, flags...))
+	flagExporter.linkObjects = android.FirstUniquePaths(append(flagExporter.linkObjects, flags...))
+}
+
+func (flagExporter *flagExporter) exportLibDeps(paths ...android.Path) {
+	flagExporter.libDeps = android.FirstUniquePaths(append(flagExporter.libDeps, paths...))
 }
 
 func (flagExporter *flagExporter) setProvider(ctx ModuleContext) {
 	ctx.SetProvider(FlagExporterInfoProvider, FlagExporterInfo{
 		LinkDirs:    flagExporter.linkDirs,
 		LinkObjects: flagExporter.linkObjects,
+		LibDeps:     flagExporter.libDeps,
 	})
 }
 
@@ -534,7 +539,8 @@ func NewFlagExporter() *flagExporter {
 type FlagExporterInfo struct {
 	Flags       []string
 	LinkDirs    []string // TODO: this should be android.Paths
-	LinkObjects []string // TODO: this should be android.Paths
+	LinkObjects android.Paths
+	LibDeps     android.Paths
 }
 
 var FlagExporterInfoProvider = blueprint.NewProvider(FlagExporterInfo{})
@@ -1250,6 +1256,7 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 				depPaths.linkDirs = append(depPaths.linkDirs, exportedInfo.LinkDirs...)
 				depPaths.depFlags = append(depPaths.depFlags, exportedInfo.Flags...)
 				depPaths.linkObjects = append(depPaths.linkObjects, exportedInfo.LinkObjects...)
+				depPaths.LibDeps = append(depPaths.LibDeps, exportedInfo.LibDeps...)
 			}
 
 			if depTag == dylibDepTag || depTag == rlibDepTag || depTag == procMacroDepTag {
@@ -1293,6 +1300,7 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 						depPaths.depLinkFlags = append(depPaths.depLinkFlags, []string{"-Wl,--whole-archive", linkObject.Path().String(), "-Wl,--no-whole-archive"}...)
 					} else if libName, ok := libNameFromFilePath(linkObject.Path()); ok {
 						depPaths.depFlags = append(depPaths.depFlags, "-lstatic="+libName)
+						depPaths.WholeStaticLibs = append(depPaths.WholeStaticLibs, linkObject.Path())
 					} else {
 						ctx.ModuleErrorf("'%q' cannot be listed as a whole_static_library in Rust modules unless the output is prefixed by 'lib'", depName, ctx.ModuleName())
 					}
@@ -1300,7 +1308,7 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 
 				// Add this to linkObjects to pass the library directly to the linker as well. This propagates
 				// to dependencies to avoid having to redeclare static libraries for dependents of the dylib variant.
-				depPaths.linkObjects = append(depPaths.linkObjects, linkObject.String())
+				depPaths.linkObjects = append(depPaths.linkObjects, linkObject.AsPaths()...)
 				depPaths.linkDirs = append(depPaths.linkDirs, linkPath)
 
 				exportedInfo := ctx.OtherModuleProvider(dep, cc.FlagExporterInfoProvider).(cc.FlagExporterInfo)
@@ -1326,7 +1334,7 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 				linkPath = linkPathFromFilePath(linkObject.Path())
 
 				depPaths.linkDirs = append(depPaths.linkDirs, linkPath)
-				depPaths.linkObjects = append(depPaths.linkObjects, linkObject.String())
+				depPaths.linkObjects = append(depPaths.linkObjects, linkObject.AsPaths()...)
 				depPaths.depIncludePaths = append(depPaths.depIncludePaths, exportedInfo.IncludeDirs...)
 				depPaths.depSystemIncludePaths = append(depPaths.depSystemIncludePaths, exportedInfo.SystemIncludeDirs...)
 				depPaths.depClangFlags = append(depPaths.depClangFlags, exportedInfo.Flags...)
@@ -1352,7 +1360,9 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 			// Make sure these dependencies are propagated
 			if lib, ok := mod.compiler.(exportedFlagsProducer); ok && exportDep {
 				lib.exportLinkDirs(linkPath)
-				lib.exportLinkObjects(linkObject.String())
+				if linkObject.Valid() {
+					lib.exportLinkObjects(linkObject.Path())
+				}
 			}
 		} else {
 			switch {
@@ -1384,19 +1394,16 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 		procMacroDepFiles = append(procMacroDepFiles, RustLibrary{Path: dep.UnstrippedOutputFile(), CrateName: dep.CrateName()})
 	}
 
-	var staticLibDepFiles android.Paths
+	var libDepFiles android.Paths
 	for _, dep := range directStaticLibDeps {
-		staticLibDepFiles = append(staticLibDepFiles, dep.OutputFile().Path())
+		libDepFiles = append(libDepFiles, dep.OutputFile().Path())
 	}
 
-	var sharedLibFiles android.Paths
-	var sharedLibDepFiles android.Paths
 	for _, dep := range directSharedLibDeps {
-		sharedLibFiles = append(sharedLibFiles, dep.SharedLibrary)
 		if dep.TableOfContents.Valid() {
-			sharedLibDepFiles = append(sharedLibDepFiles, dep.TableOfContents.Path())
+			libDepFiles = append(libDepFiles, dep.TableOfContents.Path())
 		} else {
-			sharedLibDepFiles = append(sharedLibDepFiles, dep.SharedLibrary)
+			libDepFiles = append(libDepFiles, dep.SharedLibrary)
 		}
 	}
 
@@ -1412,15 +1419,13 @@ func (mod *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
 
 	depPaths.RLibs = append(depPaths.RLibs, rlibDepFiles...)
 	depPaths.DyLibs = append(depPaths.DyLibs, dylibDepFiles...)
-	depPaths.SharedLibs = append(depPaths.SharedLibs, sharedLibFiles...)
+	depPaths.LibDeps = append(depPaths.LibDeps, libDepFiles...)
-	depPaths.SharedLibDeps = append(depPaths.SharedLibDeps, sharedLibDepFiles...)
-	depPaths.StaticLibs = append(depPaths.StaticLibs, staticLibDepFiles...)
 	depPaths.ProcMacros = append(depPaths.ProcMacros, procMacroDepFiles...)
 	depPaths.SrcDeps = append(depPaths.SrcDeps, srcProviderDepFiles...)
 
 	// Dedup exported flags from dependencies
 	depPaths.linkDirs = android.FirstUniqueStrings(depPaths.linkDirs)
-	depPaths.linkObjects = android.FirstUniqueStrings(depPaths.linkObjects)
+	depPaths.linkObjects = android.FirstUniquePaths(depPaths.linkObjects)
 	depPaths.depFlags = android.FirstUniqueStrings(depPaths.depFlags)
 	depPaths.depClangFlags = android.FirstUniqueStrings(depPaths.depClangFlags)
 	depPaths.depIncludePaths = android.FirstUniquePaths(depPaths.depIncludePaths)

rust/rust_test.go

@@ -258,6 +258,7 @@ func TestDepsTracking(t *testing.T) {
 	`)
 	module := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Module().(*Module)
 	rustc := ctx.ModuleForTests("librlib", "linux_glibc_x86_64_rlib_rlib-std").Rule("rustc")
+	rustLink := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Rule("rustLink")
 
 	// Since dependencies are added to AndroidMk* properties, we can check these to see if they've been picked up.
 	if !android.InList("libdylib", module.Properties.AndroidMkDylibs) {
@@ -284,16 +285,16 @@ func TestDepsTracking(t *testing.T) {
 		t.Errorf("-lstatic flag not being passed to rustc for static library %#v", rustc.Args["rustcFlags"])
 	}
 
-	if !strings.Contains(rustc.Args["linkFlags"], "cc_stubs_dep.so") {
+	if !strings.Contains(rustLink.Args["linkFlags"], "cc_stubs_dep.so") {
-		t.Errorf("shared cc_library not being passed to rustc linkFlags %#v", rustc.Args["linkFlags"])
+		t.Errorf("shared cc_library not being passed to rustc linkFlags %#v", rustLink.Args["linkFlags"])
 	}
 
-	if !android.SuffixInList(rustc.OrderOnly.Strings(), "cc_stubs_dep.so") {
+	if !android.SuffixInList(rustLink.OrderOnly.Strings(), "cc_stubs_dep.so") {
-		t.Errorf("shared cc dep not being passed as order-only to rustc %#v", rustc.OrderOnly.Strings())
+		t.Errorf("shared cc dep not being passed as order-only to rustc %#v", rustLink.OrderOnly.Strings())
 	}
 
-	if !android.SuffixInList(rustc.Implicits.Strings(), "cc_stubs_dep.so.toc") {
+	if !android.SuffixInList(rustLink.Implicits.Strings(), "cc_stubs_dep.so.toc") {
-		t.Errorf("shared cc dep TOC not being passed as implicit to rustc %#v", rustc.Implicits.Strings())
+		t.Errorf("shared cc dep TOC not being passed as implicit to rustc %#v", rustLink.Implicits.Strings())
 	}
 }
 

rust/sanitize_test.go

@@ -35,7 +35,7 @@ func checkHasMemtagNote(t *testing.T, m android.TestingModule, expected MemtagNo
 	note_sync := "note_memtag_heap_sync"
 
 	found := None
-	implicits := m.Rule("rustc").Implicits
+	implicits := m.Rule("rustLink").Implicits
 	for _, lib := range implicits {
 		if strings.Contains(lib.Rel(), note_async) {
 			found = Async

rust/vendor_snapshot_test.go

@@ -941,7 +941,7 @@ func TestVendorSnapshotUse(t *testing.T) {
 	ctx := testRustVndkFsVersions(t, "", mockFS, "30", "current", "31")
 
 	// libclient uses libvndk.vndk.30.arm64, libvendor.vendor_static.30.arm64, libvendor_without_snapshot
-	libclientLdFlags := ctx.ModuleForTests("libclient", sharedVariant).Rule("rustc").Args["linkFlags"]
+	libclientLdFlags := ctx.ModuleForTests("libclient", sharedVariant).Rule("rustLink").Args["linkFlags"]
 	for _, input := range [][]string{
 		[]string{sharedVariant, "libvndk.vndk.30.arm64"},
 		[]string{staticVariant, "libvendor.vendor_static.30.arm64"},
@@ -997,7 +997,7 @@ func TestVendorSnapshotUse(t *testing.T) {
 		t.Errorf("Unexpected rust rlib name in AndroidMk: %q, expected: %q\n", rustVendorBinMkRlibName, expectedRustVendorSnapshotName)
 	}
 
-	binWithoutSnapshotLdFlags := ctx.ModuleForTests("bin_without_snapshot", binaryVariant).Rule("rustc").Args["linkFlags"]
+	binWithoutSnapshotLdFlags := ctx.ModuleForTests("bin_without_snapshot", binaryVariant).Rule("rustLink").Args["linkFlags"]
 	libVndkStaticOutputPaths := cc.GetOutputPaths(ctx, staticVariant, []string{"libvndk.vendor_static.30.arm64"})
 	if !strings.Contains(binWithoutSnapshotLdFlags, libVndkStaticOutputPaths[0].String()) {
 		t.Errorf("libflags for bin_without_snapshot must contain %#v, but was %#v",

scripts/mkcratersp.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 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.
+#
+
+"""
+This script is used as a replacement for the Rust linker. It converts a linker
+command line into a rspfile that can be used during the link phase.
+"""
+
+import os
+import shutil
+import subprocess
+import sys
+
+def create_archive(out, objects, archives):
+  mricmd = f'create {out}\n'
+  for o in objects:
+    mricmd += f'addmod {o}\n'
+  for a in archives:
+    mricmd += f'addlib {a}\n'
+  mricmd += 'save\nend\n'
+  subprocess.run([os.getenv('AR'), '-M'], encoding='utf-8', input=mricmd, check=True)
+
+objects = []
+archives = []
+linkdirs = []
+libs = []
+temp_archives = []
+version_script = None
+
+for i, arg in enumerate(sys.argv):
+  if arg == '-o':
+    out = sys.argv[i+1]
+  if arg == '-L':
+    linkdirs.append(sys.argv[i+1])
+  if arg.startswith('-l') or arg == '-shared':
+    libs.append(arg)
+  if arg.startswith('-Wl,--version-script='):
+    version_script = arg[21:]
+  if arg[0] == '-':
+    continue
+  if arg.endswith('.o') or arg.endswith('.rmeta'):
+    objects.append(arg)
+  if arg.endswith('.rlib'):
+    if arg.startswith(os.getenv('TMPDIR')):
+      temp_archives.append(arg)
+    else:
+      archives.append(arg)
+
+create_archive(f'{out}.whole.a', objects, [])
+create_archive(f'{out}.a', [], temp_archives)
+
+with open(out, 'w') as f:
+  print(f'-Wl,--whole-archive', file=f)
+  print(f'{out}.whole.a', file=f)
+  print(f'-Wl,--no-whole-archive', file=f)
+  print(f'{out}.a', file=f)
+  for a in archives:
+    print(a, file=f)
+  for linkdir in linkdirs:
+    print(f'-L{linkdir}', file=f)
+  for l in libs:
+    print(l, file=f)
+  if version_script:
+    shutil.copyfile(version_script, f'{out}.version_script')
+    print(f'-Wl,--version-script={out}.version_script', file=f)