Merge "rust: Emit toc files for cdylibs"
diff --git a/cc/builder.go b/cc/builder.go
index abd5f1d..72c2fa5 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -949,8 +949,7 @@
 }
 
 // Generate a rule for extracting a table of contents from a shared library (.so)
-func transformSharedObjectToToc(ctx android.ModuleContext, inputFile android.Path,
-	outputFile android.WritablePath, flags builderFlags) {
+func TransformSharedObjectToToc(ctx android.ModuleContext, inputFile android.Path, outputFile android.WritablePath) {
 
 	var format string
 	if ctx.Darwin() {
diff --git a/cc/library.go b/cc/library.go
index c3f7305..a394409 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -1377,7 +1377,7 @@
 	// depending on a table of contents file instead of the library itself.
 	tocFile := outputFile.ReplaceExtension(ctx, flags.Toolchain.ShlibSuffix()[1:]+".toc")
 	library.tocFile = android.OptionalPathForPath(tocFile)
-	transformSharedObjectToToc(ctx, outputFile, tocFile, builderFlags)
+	TransformSharedObjectToToc(ctx, outputFile, tocFile)
 
 	stripFlags := flagsToStripFlags(flags)
 	needsStrip := library.stripper.NeedsStrip(ctx)
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index 3401e36..16945ac 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -114,8 +114,6 @@
 	// TODO(ccross): verify shared library dependencies
 	srcs := p.prebuiltSrcs(ctx)
 	if len(srcs) > 0 {
-		builderFlags := flagsToBuilderFlags(flags)
-
 		if len(srcs) > 1 {
 			ctx.PropertyErrorf("srcs", "multiple prebuilt source files")
 			return nil
@@ -152,7 +150,7 @@
 			// depending on a table of contents file instead of the library itself.
 			tocFile := android.PathForModuleOut(ctx, libName+".toc")
 			p.tocFile = android.OptionalPathForPath(tocFile)
-			transformSharedObjectToToc(ctx, outputFile, tocFile, builderFlags)
+			TransformSharedObjectToToc(ctx, outputFile, tocFile)
 
 			if ctx.Windows() && p.properties.Windows_import_lib != nil {
 				// Consumers of this library actually links to the import library in build
diff --git a/cc/snapshot_prebuilt.go b/cc/snapshot_prebuilt.go
index 9570664..d9b0bbe 100644
--- a/cc/snapshot_prebuilt.go
+++ b/cc/snapshot_prebuilt.go
@@ -476,13 +476,12 @@
 
 	if p.shared() {
 		libName := in.Base()
-		builderFlags := flagsToBuilderFlags(flags)
 
 		// Optimize out relinking against shared libraries whose interface hasn't changed by
 		// depending on a table of contents file instead of the library itself.
 		tocFile := android.PathForModuleOut(ctx, libName+".toc")
 		p.tocFile = android.OptionalPathForPath(tocFile)
-		transformSharedObjectToToc(ctx, in, tocFile, builderFlags)
+		TransformSharedObjectToToc(ctx, in, tocFile)
 
 		ctx.SetProvider(SharedLibraryInfoProvider, SharedLibraryInfo{
 			SharedLibrary: in,
diff --git a/cc/vndk_prebuilt.go b/cc/vndk_prebuilt.go
index da34f36..31b6d10 100644
--- a/cc/vndk_prebuilt.go
+++ b/cc/vndk_prebuilt.go
@@ -144,7 +144,6 @@
 		// current VNDK prebuilts are only shared libs.
 
 		in := p.singleSourcePath(ctx)
-		builderFlags := flagsToBuilderFlags(flags)
 		p.unstrippedOutputFile = in
 		libName := in.Base()
 		if p.stripper.NeedsStrip(ctx) {
@@ -158,7 +157,7 @@
 		// depending on a table of contents file instead of the library itself.
 		tocFile := android.PathForModuleOut(ctx, libName+".toc")
 		p.tocFile = android.OptionalPathForPath(tocFile)
-		transformSharedObjectToToc(ctx, in, tocFile, builderFlags)
+		TransformSharedObjectToToc(ctx, in, tocFile)
 
 		p.androidMkSuffix = p.NameSuffix()
 
diff --git a/rust/androidmk.go b/rust/androidmk.go
index 630805a..e429416 100644
--- a/rust/androidmk.go
+++ b/rust/androidmk.go
@@ -137,12 +137,16 @@
 	} else if library.shared() {
 		ret.Class = "SHARED_LIBRARIES"
 	}
-
 	if library.distFile.Valid() {
 		ret.DistFiles = android.MakeDefaultDistFiles(library.distFile.Path())
 	}
+	ret.ExtraEntries = append(ret.ExtraEntries,
+		func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
+			if library.tocFile.Valid() {
+				entries.SetString("LOCAL_SOONG_TOC", library.tocFile.String())
+			}
+		})
 }
-
 func (procMacro *procMacroDecorator) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkEntries) {
 	ctx.SubAndroidMk(ret, procMacro.baseCompiler)
 
diff --git a/rust/builder.go b/rust/builder.go
index f79cf9b..6f20347 100644
--- a/rust/builder.go
+++ b/rust/builder.go
@@ -185,7 +185,7 @@
 }
 
 func transformSrctoCrate(ctx ModuleContext, main android.Path, deps PathDeps, flags Flags,
-	outputFile android.WritablePath, crate_type string) buildOutput {
+	outputFile android.WritablePath, crateType string) buildOutput {
 
 	var inputs android.Paths
 	var implicits android.Paths
@@ -204,7 +204,7 @@
 	// Collect rustc flags
 	rustcFlags = append(rustcFlags, flags.GlobalRustFlags...)
 	rustcFlags = append(rustcFlags, flags.RustFlags...)
-	rustcFlags = append(rustcFlags, "--crate-type="+crate_type)
+	rustcFlags = append(rustcFlags, "--crate-type="+crateType)
 	if crateName != "" {
 		rustcFlags = append(rustcFlags, "--crate-name="+crateName)
 	}
diff --git a/rust/library.go b/rust/library.go
index 38dae4d..ea14e6d 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -102,6 +102,9 @@
 	sourceProvider    SourceProvider
 
 	collectedSnapshotHeaders android.Paths
+
+	// table-of-contents file for cdylib crates to optimize out relinking when possible
+	tocFile android.OptionalPath
 }
 
 type libraryInterface interface {
@@ -137,12 +140,18 @@
 	BuildOnlyDylib()
 	BuildOnlyStatic()
 	BuildOnlyShared()
+
+	toc() android.OptionalPath
 }
 
 func (library *libraryDecorator) nativeCoverage() bool {
 	return true
 }
 
+func (library *libraryDecorator) toc() android.OptionalPath {
+	return library.tocFile
+}
+
 func (library *libraryDecorator) rlib() bool {
 	return library.MutatedProperties.VariantIsRlib
 }
@@ -519,9 +528,16 @@
 	}
 
 	if library.shared() {
+		// Optimize out relinking against shared libraries whose interface hasn't changed by
+		// depending on a table of contents file instead of the library itself.
+		tocFile := outputFile.ReplaceExtension(ctx, flags.Toolchain.SharedLibSuffix()[1:]+".toc")
+		library.tocFile = android.OptionalPathForPath(tocFile)
+		cc.TransformSharedObjectToToc(ctx, outputFile, tocFile)
+
 		ctx.SetProvider(cc.SharedLibraryInfoProvider, cc.SharedLibraryInfo{
-			SharedLibrary: outputFile,
-			Target:        ctx.Target(),
+			TableOfContents: android.OptionalPathForPath(tocFile),
+			SharedLibrary:   outputFile,
+			Target:          ctx.Target(),
 		})
 	}
 
diff --git a/rust/library_test.go b/rust/library_test.go
index cb4ef7e..edb9c89 100644
--- a/rust/library_test.go
+++ b/rust/library_test.go
@@ -160,6 +160,26 @@
 	}
 }
 
+func TestSharedLibraryToc(t *testing.T) {
+	ctx := testRust(t, `
+		rust_ffi_shared {
+			name: "libfoo",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+		}
+		cc_binary {
+			name: "fizzbuzz",
+			shared_libs: ["libfoo"],
+		}`)
+
+	fizzbuzz := ctx.ModuleForTests("fizzbuzz", "android_arm64_armv8-a").Rule("ld")
+
+	if !android.SuffixInList(fizzbuzz.Implicits.Strings(), "libfoo.so.toc") {
+		t.Errorf("missing expected libfoo.so.toc implicit dependency, instead found: %#v",
+			fizzbuzz.Implicits.Strings())
+	}
+}
+
 func TestStaticLibraryLinkage(t *testing.T) {
 	ctx := testRust(t, `
 		rust_ffi_static {
diff --git a/rust/rust.go b/rust/rust.go
index c465cb6..c159e4a 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -281,8 +281,8 @@
 
 func (mod *Module) Toc() android.OptionalPath {
 	if mod.compiler != nil {
-		if _, ok := mod.compiler.(libraryInterface); ok {
-			return android.OptionalPath{}
+		if lib, ok := mod.compiler.(libraryInterface); ok {
+			return lib.toc()
 		}
 	}
 	panic(fmt.Errorf("Toc() called on non-library module: %q", mod.BaseModuleName()))