rust: strip libraries and binaries

Reuses the cc.Stripper logic. Abstracts Stripper to avoid the spreading
of references to the cc package.

rustc requires unstripped libraries (precisely, with the `.rustc`
section) when building dependent targets. Contrary to cc, the output of
a compiler module will remain unstripped and only an extra build rule
will be added. This rule will be referenced at install time (in
baseCompiler.install or androidmk).

This change drastically reduces the size of the installed libraries:
(unstripped, from out/target/product/crosshatch/system)
$ find . -name \*.dylib.so -print0 | du -c --files0-from=-
149996  total

(stripped, with this change)
$ find . -name \*.dylib.so -print0 | du -c --files0-from=-
42380   total

Bug: 153430439
Test: cd external/rust; mma
Change-Id: I94fd8bbcec97e0610aa325d3db4460be84d01734

1 files changed, 15 insertions, 7 deletions

diff --git a/rust/library.go b/rust/library.go
index 450c9d429..a44293307 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -78,6 +78,7 @@ type LibraryMutatedProperties struct {
 type libraryDecorator struct {
 	*baseCompiler
 	*flagExporter
+	stripper Stripper
 
 	Properties        LibraryCompilerProperties
 	MutatedProperties LibraryMutatedProperties
@@ -338,7 +339,8 @@ func NewRustLibrary(hod android.HostOrDeviceSupported) (*Module, *libraryDecorat
 func (library *libraryDecorator) compilerProps() []interface{} {
 	return append(library.baseCompiler.compilerProps(),
 		&library.Properties,
-		&library.MutatedProperties)
+		&library.MutatedProperties,
+		&library.stripper.StripProperties)
 }
 
 func (library *libraryDecorator) compilerDeps(ctx DepsContext, deps Deps) Deps {
@@ -371,7 +373,8 @@ func (library *libraryDecorator) compilerFlags(ctx ModuleContext, flags Flags) F
 }
 
 func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) android.Path {
-	var outputFile android.WritablePath
+	var outputFile android.ModuleOutPath
+	var fileName string
 	var srcPath android.Path
 
 	if library.sourceProvider != nil {
@@ -391,31 +394,37 @@ func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps Pa
 	}
 
 	if library.rlib() {
-		fileName := library.getStem(ctx) + ctx.toolchain().RlibSuffix()
+		fileName = library.getStem(ctx) + ctx.toolchain().RlibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
 		outputs := TransformSrctoRlib(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
 		library.coverageFile = outputs.coverageFile
 	} else if library.dylib() {
-		fileName := library.getStem(ctx) + ctx.toolchain().DylibSuffix()
+		fileName = library.getStem(ctx) + ctx.toolchain().DylibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
 		outputs := TransformSrctoDylib(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
 		library.coverageFile = outputs.coverageFile
 	} else if library.static() {
-		fileName := library.getStem(ctx) + ctx.toolchain().StaticLibSuffix()
+		fileName = library.getStem(ctx) + ctx.toolchain().StaticLibSuffix()
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
 		outputs := TransformSrctoStatic(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
 		library.coverageFile = outputs.coverageFile
 	} else if library.shared() {
-		fileName := library.sharedLibFilename(ctx)
+		fileName = library.sharedLibFilename(ctx)
 		outputFile = android.PathForModuleOut(ctx, fileName)
 
 		outputs := TransformSrctoShared(ctx, srcPath, deps, flags, outputFile, deps.linkDirs)
 		library.coverageFile = outputs.coverageFile
 	}
 
+	if !library.rlib() && library.stripper.NeedsStrip(ctx) {
+		strippedOutputFile := android.PathForModuleOut(ctx, "stripped", fileName)
+		library.stripper.StripExecutableOrSharedLib(ctx, outputFile, strippedOutputFile)
+		library.strippedOutputFile = android.OptionalPathForPath(strippedOutputFile)
+	}
+
 	var coverageFiles android.Paths
 	if library.coverageFile != nil {
 		coverageFiles = append(coverageFiles, library.coverageFile)
@@ -430,7 +439,6 @@ func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps Pa
 		library.exportDepFlags(deps.depFlags...)
 		library.exportLinkObjects(deps.linkObjects...)
 	}
-	library.unstrippedOutputFile = outputFile
 
 	return outputFile
 }