<Hermetic> Replace Soong Python bootstrap process with embedded

launcher.

For Python2, we bundle embedded launcher as bootstrapper within every
.par file. This feature is only enabled for linux_x86_64 for now. We
provide a user flag: hermetic_enabled within bp file. By default, Pyhon2
still use classic bootstrapping way to construct .par file and relys on
host interpreter. Once embedded_launcher is enabled, launcher will be
used to bootstrap .par file and execute user program.

For Python3, the launcher will be ready soon, and for now it still relys
on classic bootstrapping.

Test: Real example is used to test.

Bug: b/63018041

Change-Id: I28deba413d8ad3af407595e46f77d663e79a3705

1 files changed, 69 insertions, 59 deletions

diff --git a/python/binary.go b/python/binary.go
index ae2693b98..91b7a5487 100644
--- a/python/binary.go
+++ b/python/binary.go
@@ -21,6 +21,8 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/google/blueprint"
+
 	"android/soong/android"
 )
 
@@ -28,67 +30,63 @@ func init() {
 	android.RegisterModuleType("python_binary_host", PythonBinaryHostFactory)
 }
 
-type PythonBinaryBaseProperties struct {
+type BinaryProperties struct {
 	// the name of the source file that is the main entry point of the program.
 	// this file must also be listed in srcs.
 	// If left unspecified, module name is used instead.
 	// If name doesn’t match any filename in srcs, main must be specified.
-	Main string
+	Main string `android:"arch_variant"`
 
 	// set the name of the output binary.
-	Stem string
+	Stem string `android:"arch_variant"`
 
 	// append to the name of the output binary.
-	Suffix string
+	Suffix string `android:"arch_variant"`
 }
 
-type pythonBinaryBase struct {
-	pythonBaseModule
-
-	binaryProperties PythonBinaryBaseProperties
+type binaryDecorator struct {
+	binaryProperties BinaryProperties
 
-	// soong_zip arguments from all its dependencies.
-	depsParSpecs []parSpec
-
-	// Python runfiles paths from all its dependencies.
-	depsPyRunfiles []string
+	baseInstaller *pythonInstaller
 }
 
-type PythonBinaryHost struct {
-	pythonBinaryBase
+type IntermPathProvider interface {
+	IntermPathForModuleOut() android.OptionalPath
 }
 
-var _ PythonSubModule = (*PythonBinaryHost)(nil)
-
-type pythonBinaryHostDecorator struct {
-	pythonDecorator
-}
-
-func (p *pythonBinaryHostDecorator) install(ctx android.ModuleContext, file android.Path) {
-	p.pythonDecorator.baseInstaller.install(ctx, file)
+func (binary *binaryDecorator) install(ctx android.ModuleContext, file android.Path) {
+	binary.baseInstaller.install(ctx, file)
 }
 
 var (
 	stubTemplateHost = "build/soong/python/scripts/stub_template_host.txt"
 )
 
-func PythonBinaryHostFactory() android.Module {
-	decorator := &pythonBinaryHostDecorator{
-		pythonDecorator: pythonDecorator{baseInstaller: NewPythonInstaller("bin")}}
+func NewBinary(hod android.HostOrDeviceSupported) (*Module, *binaryDecorator) {
+	module := newModule(hod, android.MultilibFirst)
+	decorator := &binaryDecorator{baseInstaller: NewPythonInstaller("bin")}
 
-	module := &PythonBinaryHost{}
-	module.pythonBaseModule.installer = decorator
-	module.AddProperties(&module.binaryProperties)
+	module.bootstrapper = decorator
+	module.installer = decorator
 
-	return InitPythonBaseModule(&module.pythonBinaryBase.pythonBaseModule,
-		&module.pythonBinaryBase, android.HostSupportedNoCross)
+	return module, decorator
 }
 
-func (p *pythonBinaryBase) GeneratePythonBuildActions(ctx android.ModuleContext) android.OptionalPath {
-	p.pythonBaseModule.GeneratePythonBuildActions(ctx)
+func PythonBinaryHostFactory() android.Module {
+	module, _ := NewBinary(android.HostSupportedNoCross)
+
+	return module.Init()
+}
 
-	// no Python source file for compiling par file.
-	if len(p.pythonBaseModule.srcsPathMappings) == 0 && len(p.depsPyRunfiles) == 0 {
+func (binary *binaryDecorator) bootstrapperProps() []interface{} {
+	return []interface{}{&binary.binaryProperties}
+}
+
+func (binary *binaryDecorator) bootstrap(ctx android.ModuleContext, actual_version string,
+	embedded_launcher bool, srcsPathMappings []pathMapping, parSpec parSpec,
+	depsPyRunfiles []string, depsParSpecs []parSpec) android.OptionalPath {
+	// no Python source file for compiling .par file.
+	if len(srcsPathMappings) == 0 {
 		return android.OptionalPath{}
 	}
 
@@ -100,10 +98,10 @@ func (p *pythonBinaryBase) GeneratePythonBuildActions(ctx android.ModuleContext)
 	existingPyPkgSet := make(map[string]bool)
 
 	wholePyRunfiles := []string{}
-	for _, path := range p.pythonBaseModule.srcsPathMappings {
+	for _, path := range srcsPathMappings {
 		wholePyRunfiles = append(wholePyRunfiles, path.dest)
 	}
-	wholePyRunfiles = append(wholePyRunfiles, p.depsPyRunfiles...)
+	wholePyRunfiles = append(wholePyRunfiles, depsPyRunfiles...)
 
 	// find all the runfiles dirs which have been treated as packages.
 	for _, path := range wholePyRunfiles {
@@ -130,50 +128,62 @@ func (p *pythonBinaryBase) GeneratePythonBuildActions(ctx android.ModuleContext)
 		populateNewPyPkgs(parentPath, existingPyPkgSet, newPyPkgSet, &newPyPkgs)
 	}
 
-	main := p.getPyMainFile(ctx)
+	main := binary.getPyMainFile(ctx, srcsPathMappings)
 	if main == "" {
 		return android.OptionalPath{}
 	}
-	interp := p.getInterpreter(ctx)
-	if interp == "" {
-		return android.OptionalPath{}
+
+	var launcher_path android.Path
+	if embedded_launcher {
+		ctx.VisitDirectDeps(func(m blueprint.Module) {
+			if ctx.OtherModuleDependencyTag(m) != launcherTag {
+				return
+			}
+			if provider, ok := m.(IntermPathProvider); ok {
+				if launcher_path != nil {
+					panic(fmt.Errorf("launcher path was found before: %q",
+						launcher_path))
+				}
+				launcher_path = provider.IntermPathForModuleOut().Path()
+			}
+		})
 	}
 
-	// we need remove "runfiles/" suffix since stub script starts
-	// searching for main file in each sub-dir of "runfiles" directory tree.
-	binFile := registerBuildActionForParFile(ctx, p.getInterpreter(ctx),
-		strings.TrimPrefix(main, runFiles+"/"), p.getStem(ctx),
-		newPyPkgs, append(p.depsParSpecs, p.pythonBaseModule.parSpec))
+	binFile := registerBuildActionForParFile(ctx, embedded_launcher, launcher_path,
+		binary.getHostInterpreterName(ctx, actual_version),
+		main, binary.getStem(ctx), newPyPkgs, append(depsParSpecs, parSpec))
 
 	return android.OptionalPathForPath(binFile)
 }
 
-// get interpreter path.
-func (p *pythonBinaryBase) getInterpreter(ctx android.ModuleContext) string {
+// get host interpreter name.
+func (binary *binaryDecorator) getHostInterpreterName(ctx android.ModuleContext,
+	actual_version string) string {
 	var interp string
-	switch p.pythonBaseModule.properties.ActualVersion {
+	switch actual_version {
 	case pyVersion2:
 		interp = "python2"
 	case pyVersion3:
 		interp = "python3"
 	default:
 		panic(fmt.Errorf("unknown Python actualVersion: %q for module: %q.",
-			p.properties.ActualVersion, ctx.ModuleName()))
+			actual_version, ctx.ModuleName()))
 	}
 
 	return interp
 }
 
 // find main program path within runfiles tree.
-func (p *pythonBinaryBase) getPyMainFile(ctx android.ModuleContext) string {
+func (binary *binaryDecorator) getPyMainFile(ctx android.ModuleContext,
+	srcsPathMappings []pathMapping) string {
 	var main string
-	if p.binaryProperties.Main == "" {
-		main = p.BaseModuleName() + pyExt
+	if binary.binaryProperties.Main == "" {
+		main = ctx.ModuleName() + pyExt
 	} else {
-		main = p.binaryProperties.Main
+		main = binary.binaryProperties.Main
 	}
 
-	for _, path := range p.pythonBaseModule.srcsPathMappings {
+	for _, path := range srcsPathMappings {
 		if main == path.src.Rel() {
 			return path.dest
 		}
@@ -183,13 +193,13 @@ func (p *pythonBinaryBase) getPyMainFile(ctx android.ModuleContext) string {
 	return ""
 }
 
-func (p *pythonBinaryBase) getStem(ctx android.ModuleContext) string {
+func (binary *binaryDecorator) getStem(ctx android.ModuleContext) string {
 	stem := ctx.ModuleName()
-	if p.binaryProperties.Stem != "" {
-		stem = p.binaryProperties.Stem
+	if binary.binaryProperties.Stem != "" {
+		stem = binary.binaryProperties.Stem
 	}
 
-	return stem + p.binaryProperties.Suffix
+	return stem + binary.binaryProperties.Suffix
 }
 
 // Sets the given directory and all its ancestor directories as Python packages.