Remove python2 support from soong rules

Python2 has been removed from the android build.

Removing the python version transition mutator should lead to some
slight analysis time performance improvements.

I also made embedded_launcher in base_properties no longer
blueprint:"mutated", so that we can migrate usages to the main property
struct and remove the `version` property struct.

Many python tests were not being run due to a
`if d.desc != "module with duplicate runfile path" { continue }` line,
I removed that and fixed the tests. I also removed the test for an
error when there are no source files, because that check has been
relaxed since, and I think it's legitimate to have a python library that
only has data files, not source files. And there are some of those
libraries in the source tree.

Bug: 203436762
Test: m nothing --no-skip-soong-tests
Change-Id: Idf18e39233418237ecc83f70f65d83d4ea496633

6 files changed, 61 insertions, 293 deletions

diff --git a/python/binary.go b/python/binary.go
index a3acb347d..4d6e11816 100644
--- a/python/binary.go
+++ b/python/binary.go
@@ -23,6 +23,7 @@ import (
 
 	"android/soong/android"
 	"android/soong/cc"
+
 	"github.com/google/blueprint"
 )
 
@@ -143,8 +144,7 @@ func (p *PythonBinaryModule) buildBinary(ctx android.ModuleContext) {
 	}
 	srcsZips = append(srcsZips, depsSrcsZips...)
 	p.installSource = registerBuildActionForParFile(ctx, embeddedLauncher, launcherPath,
-		p.getHostInterpreterName(ctx, p.properties.Actual_version),
-		main, p.getStem(ctx), srcsZips)
+		"python3", main, p.getStem(ctx), srcsZips)
 
 	var sharedLibs []string
 	// if embedded launcher is enabled, we need to collect the shared library dependencies of the
@@ -205,23 +205,6 @@ func (b *PythonBinaryModule) autorun() bool {
 	return BoolDefault(b.binaryProperties.Autorun, true)
 }
 
-// get host interpreter name.
-func (p *PythonBinaryModule) getHostInterpreterName(ctx android.ModuleContext,
-	actualVersion string) string {
-	var interp string
-	switch actualVersion {
-	case pyVersion2:
-		interp = "python2.7"
-	case pyVersion3:
-		interp = "python3"
-	default:
-		panic(fmt.Errorf("unknown Python actualVersion: %q for module: %q.",
-			actualVersion, ctx.ModuleName()))
-	}
-
-	return interp
-}
-
 // find main program path within runfiles tree.
 func (p *PythonBinaryModule) getPyMainFile(ctx android.ModuleContext,
 	srcsPathMappings []pathMapping) string {
diff --git a/python/defaults.go b/python/defaults.go
index 3dc5bc4d2..b5ee2bcb1 100644
--- a/python/defaults.go
+++ b/python/defaults.go
@@ -18,10 +18,6 @@ import (
 	"android/soong/android"
 )
 
-func init() {
-	android.RegisterModuleType("python_defaults", DefaultsFactory)
-}
-
 type Defaults struct {
 	android.ModuleBase
 	android.DefaultsModuleBase
diff --git a/python/library.go b/python/library.go
index 7cdb80b87..c197028df 100644
--- a/python/library.go
+++ b/python/library.go
@@ -27,6 +27,7 @@ func init() {
 func registerPythonLibraryComponents(ctx android.RegistrationContext) {
 	ctx.RegisterModuleType("python_library_host", PythonLibraryHostFactory)
 	ctx.RegisterModuleType("python_library", PythonLibraryFactory)
+	ctx.RegisterModuleType("python_defaults", DefaultsFactory)
 }
 
 func PythonLibraryHostFactory() android.Module {
diff --git a/python/python.go b/python/python.go
index 09af62ea5..10c11ada0 100644
--- a/python/python.go
+++ b/python/python.go
@@ -23,6 +23,7 @@ import (
 	"strings"
 
 	"android/soong/cc"
+
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 
@@ -39,19 +40,6 @@ type PythonLibraryInfo struct {
 
 var PythonLibraryInfoProvider = blueprint.NewProvider[PythonLibraryInfo]()
 
-func init() {
-	registerPythonMutators(android.InitRegistrationContext)
-}
-
-func registerPythonMutators(ctx android.RegistrationContext) {
-	ctx.PreDepsMutators(RegisterPythonPreDepsMutators)
-}
-
-// Exported to support other packages using Python modules in tests.
-func RegisterPythonPreDepsMutators(ctx android.RegisterMutatorsContext) {
-	ctx.Transition("python_version", &versionSplitTransitionMutator{})
-}
-
 // the version-specific properties that apply to python modules.
 type VersionProperties struct {
 	// whether the module is required to be built with this version.
@@ -127,18 +115,14 @@ type BaseProperties struct {
 		Py3 VersionProperties `android:"arch_variant"`
 	} `android:"arch_variant"`
 
-	// the actual version each module uses after variations created.
-	// this property name is hidden from users' perspectives, and soong will populate it during
-	// runtime.
-	Actual_version string `blueprint:"mutated"`
-
-	// whether the module is required to be built with actual_version.
-	// this is set by the python version mutator based on version-specific properties
+	// This enabled property is to accept the collapsed enabled property from the VersionProperties.
+	// It is unused now, as all builds should be python3.
 	Enabled *bool `blueprint:"mutated"`
 
-	// whether the binary is required to be built with embedded launcher for this actual_version.
-	// this is set by the python version mutator based on version-specific properties
-	Embedded_launcher *bool `blueprint:"mutated"`
+	// whether the binary is required to be built with an embedded python interpreter, defaults to
+	// true. This allows taking the resulting binary outside of the build and running it on machines
+	// that don't have python installed or may have an older version of python.
+	Embedded_launcher *bool
 }
 
 // Used to store files of current module after expanding dependencies
@@ -252,8 +236,6 @@ var (
 	pathComponentRegexp      = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_-]*$`)
 	pyExt                    = ".py"
 	protoExt                 = ".proto"
-	pyVersion2               = "PY2"
-	pyVersion3               = "PY3"
 	internalPath             = "internal"
 )
 
@@ -261,71 +243,6 @@ type basePropertiesProvider interface {
 	getBaseProperties() *BaseProperties
 }
 
-type versionSplitTransitionMutator struct{}
-
-func (versionSplitTransitionMutator) Split(ctx android.BaseModuleContext) []string {
-	if base, ok := ctx.Module().(basePropertiesProvider); ok {
-		props := base.getBaseProperties()
-		var variants []string
-		// PY3 is first so that we alias the PY3 variant rather than PY2 if both
-		// are available
-		if proptools.BoolDefault(props.Version.Py3.Enabled, true) {
-			variants = append(variants, pyVersion3)
-		}
-		if proptools.BoolDefault(props.Version.Py2.Enabled, false) {
-			if ctx.ModuleName() != "py2-cmd" &&
-				ctx.ModuleName() != "py2-stdlib" {
-				ctx.PropertyErrorf("version.py2.enabled", "Python 2 is no longer supported, please convert to python 3.")
-			}
-			variants = append(variants, pyVersion2)
-		}
-		return variants
-	}
-	return []string{""}
-}
-
-func (versionSplitTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
-	return ""
-}
-
-func (versionSplitTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
-	if incomingVariation != "" {
-		return incomingVariation
-	}
-	if base, ok := ctx.Module().(basePropertiesProvider); ok {
-		props := base.getBaseProperties()
-		if proptools.BoolDefault(props.Version.Py3.Enabled, true) {
-			return pyVersion3
-		} else {
-			return pyVersion2
-		}
-	}
-
-	return ""
-}
-
-func (versionSplitTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
-	if variation == "" {
-		return
-	}
-	if base, ok := ctx.Module().(basePropertiesProvider); ok {
-		props := base.getBaseProperties()
-		props.Actual_version = variation
-
-		var versionProps *VersionProperties
-		if variation == pyVersion3 {
-			versionProps = &props.Version.Py3
-		} else if variation == pyVersion2 {
-			versionProps = &props.Version.Py2
-		}
-
-		err := proptools.AppendMatchingProperties([]interface{}{props}, versionProps, nil)
-		if err != nil {
-			panic(err)
-		}
-	}
-}
-
 func anyHasExt(paths []string, ext string) bool {
 	for _, p := range paths {
 		if filepath.Ext(p) == ext {
@@ -345,19 +262,26 @@ func (p *PythonLibraryModule) anySrcHasExt(ctx android.BottomUpMutatorContext, e
 //   - if required, specifies launcher and adds launcher dependencies,
 //   - applies python version mutations to Python dependencies
 func (p *PythonLibraryModule) DepsMutator(ctx android.BottomUpMutatorContext) {
-	android.ProtoDeps(ctx, &p.protoProperties)
+	// Flatten the version.py3 props down into the main property struct. Leftover from when
+	// there was both python2 and 3 in the build, and properties could be different between them.
+	if base, ok := ctx.Module().(basePropertiesProvider); ok {
+		props := base.getBaseProperties()
 
-	versionVariation := []blueprint.Variation{
-		{"python_version", p.properties.Actual_version},
+		err := proptools.AppendMatchingProperties([]interface{}{props}, &props.Version.Py3, nil)
+		if err != nil {
+			panic(err)
+		}
 	}
 
+	android.ProtoDeps(ctx, &p.protoProperties)
+
 	// If sources contain a proto file, add dependency on libprotobuf-python
 	if p.anySrcHasExt(ctx, protoExt) && p.Name() != "libprotobuf-python" {
-		ctx.AddVariationDependencies(versionVariation, pythonLibTag, "libprotobuf-python")
+		ctx.AddDependency(ctx.Module(), pythonLibTag, "libprotobuf-python")
 	}
 
 	// Add python library dependencies for this python version variation
-	ctx.AddVariationDependencies(versionVariation, pythonLibTag, android.LastUniqueStrings(p.properties.Libs)...)
+	ctx.AddDependency(ctx.Module(), pythonLibTag, android.LastUniqueStrings(p.properties.Libs)...)
 
 	// Emulate the data property for java_data but with the arch variation overridden to "common"
 	// so that it can point to java modules.
@@ -394,55 +318,38 @@ func (p *PythonLibraryModule) AddDepsOnPythonLauncherAndStdlib(ctx android.Botto
 		launcherSharedLibDeps = append(launcherSharedLibDeps, "libc_musl")
 	}
 
-	switch p.properties.Actual_version {
-	case pyVersion2:
-		stdLib = "py2-stdlib"
-
-		launcherModule = "py2-launcher"
-		if autorun {
-			launcherModule = "py2-launcher-autorun"
-		}
-
-		launcherSharedLibDeps = append(launcherSharedLibDeps, "libc++")
-	case pyVersion3:
-		var prebuiltStdLib bool
-		if targetForDeps.Os.Bionic() {
-			prebuiltStdLib = false
-		} else if ctx.Config().VendorConfig("cpython3").Bool("force_build_host") {
-			prebuiltStdLib = false
-		} else {
-			prebuiltStdLib = true
-		}
+	var prebuiltStdLib bool
+	if targetForDeps.Os.Bionic() {
+		prebuiltStdLib = false
+	} else if ctx.Config().VendorConfig("cpython3").Bool("force_build_host") {
+		prebuiltStdLib = false
+	} else {
+		prebuiltStdLib = true
+	}
 
-		if prebuiltStdLib {
-			stdLib = "py3-stdlib-prebuilt"
-		} else {
-			stdLib = "py3-stdlib"
-		}
+	if prebuiltStdLib {
+		stdLib = "py3-stdlib-prebuilt"
+	} else {
+		stdLib = "py3-stdlib"
+	}
 
-		launcherModule = "py3-launcher"
-		if autorun {
-			launcherModule = "py3-launcher-autorun"
-		}
-		if ctx.Config().HostStaticBinaries() && targetForDeps.Os == android.LinuxMusl {
-			launcherModule += "-static"
-		}
-		if ctx.Device() {
-			launcherSharedLibDeps = append(launcherSharedLibDeps, "liblog")
-		}
-	default:
-		panic(fmt.Errorf("unknown Python Actual_version: %q for module: %q.",
-			p.properties.Actual_version, ctx.ModuleName()))
+	launcherModule = "py3-launcher"
+	if autorun {
+		launcherModule = "py3-launcher-autorun"
 	}
+	if ctx.Config().HostStaticBinaries() && targetForDeps.Os == android.LinuxMusl {
+		launcherModule += "-static"
+	}
+	if ctx.Device() {
+		launcherSharedLibDeps = append(launcherSharedLibDeps, "liblog")
+	}
+
 	targetVariations := targetForDeps.Variations()
 	if ctx.ModuleName() != stdLib {
-		stdLibVariations := make([]blueprint.Variation, 0, len(targetVariations)+1)
-		stdLibVariations = append(stdLibVariations, blueprint.Variation{Mutator: "python_version", Variation: p.properties.Actual_version})
-		stdLibVariations = append(stdLibVariations, targetVariations...)
 		// Using AddFarVariationDependencies for all of these because they can be for a different
 		// platform, like if the python module itself was being compiled for device, we may want
 		// the python interpreter built for host so that we can precompile python sources.
-		ctx.AddFarVariationDependencies(stdLibVariations, stdLibTag, stdLib)
+		ctx.AddFarVariationDependencies(targetVariations, stdLibTag, stdLib)
 	}
 	ctx.AddFarVariationDependencies(targetVariations, launcherTag, launcherModule)
 	ctx.AddFarVariationDependencies(targetVariations, launcherSharedLibTag, launcherSharedLibDeps...)
@@ -450,6 +357,9 @@ func (p *PythonLibraryModule) AddDepsOnPythonLauncherAndStdlib(ctx android.Botto
 
 // GenerateAndroidBuildActions performs build actions common to all Python modules
 func (p *PythonLibraryModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	if proptools.BoolDefault(p.properties.Version.Py2.Enabled, false) {
+		ctx.PropertyErrorf("version.py2.enabled", "Python 2 is no longer supported, please convert to python 3.")
+	}
 	expandedSrcs := android.PathsForModuleSrcExcludes(ctx, p.properties.Srcs, p.properties.Exclude_srcs)
 	// Keep before any early returns.
 	android.SetProvider(ctx, android.TestOnlyProviderKey, android.TestModuleInformation{
diff --git a/python/python_test.go b/python/python_test.go
index 6a6bd1d91..0e97626d6 100644
--- a/python/python_test.go
+++ b/python/python_test.go
@@ -36,10 +36,8 @@ type pyModule struct {
 }
 
 var (
-	buildNamePrefix = "soong_python_test"
-	// We allow maching almost anything before the actual variant so that the os/arch variant
-	// is matched.
-	moduleVariantErrTemplate = `%s: module %q variant "[a-zA-Z0-9_]*%s": `
+	buildNamePrefix          = "soong_python_test"
+	moduleVariantErrTemplate = `%s: module %q variant "[a-zA-Z0-9_]*": `
 	pkgPathErrTemplate       = moduleVariantErrTemplate +
 		"pkg_path: %q must be a relative path contained in par file."
 	badIdentifierErrTemplate = moduleVariantErrTemplate +
@@ -48,9 +46,8 @@ var (
 		"found two files to be placed at the same location within zip %q." +
 		" First file: in module %s at path %q." +
 		" Second file: in module %s at path %q."
-	noSrcFileErr      = moduleVariantErrTemplate + "doesn't have any source files!"
-	badSrcFileExtErr  = moduleVariantErrTemplate + "srcs: found non (.py|.proto) file: %q!"
-	badDataFileExtErr = moduleVariantErrTemplate + "data: found (.py) file: %q!"
+	badSrcFileExtErr  = moduleVariantErrTemplate + `srcs: found non \(.py\|.proto\) file: %q!`
+	badDataFileExtErr = moduleVariantErrTemplate + `data: found \(.py\) file: %q!`
 	bpFile            = "Android.bp"
 
 	data = []struct {
@@ -61,20 +58,6 @@ var (
 		expectedBinaries []pyModule
 	}{
 		{
-			desc: "module without any src files",
-			mockFiles: map[string][]byte{
-				filepath.Join("dir", bpFile): []byte(
-					`python_library_host {
-						name: "lib1",
-					}`,
-				),
-			},
-			errors: []string{
-				fmt.Sprintf(noSrcFileErr,
-					"dir/Android.bp:1:1", "lib1", "PY3"),
-			},
-		},
-		{
 			desc: "module with bad src file ext",
 			mockFiles: map[string][]byte{
 				filepath.Join("dir", bpFile): []byte(
@@ -89,7 +72,7 @@ var (
 			},
 			errors: []string{
 				fmt.Sprintf(badSrcFileExtErr,
-					"dir/Android.bp:3:11", "lib1", "PY3", "dir/file1.exe"),
+					"dir/Android.bp:3:11", "lib1", "dir/file1.exe"),
 			},
 		},
 		{
@@ -111,7 +94,7 @@ var (
 			},
 			errors: []string{
 				fmt.Sprintf(badDataFileExtErr,
-					"dir/Android.bp:6:11", "lib1", "PY3", "dir/file2.py"),
+					"dir/Android.bp:6:11", "lib1", "dir/file2.py"),
 			},
 		},
 		{
@@ -146,9 +129,9 @@ var (
 			},
 			errors: []string{
 				fmt.Sprintf(pkgPathErrTemplate,
-					"dir/Android.bp:11:15", "lib2", "PY3", "a/c/../../../"),
+					"dir/Android.bp:11:15", "lib2", "a/c/../../../"),
 				fmt.Sprintf(pkgPathErrTemplate,
-					"dir/Android.bp:19:15", "lib3", "PY3", "/a/c/../../"),
+					"dir/Android.bp:19:15", "lib3", "/a/c/../../"),
 			},
 		},
 		{
@@ -171,11 +154,11 @@ var (
 			},
 			errors: []string{
 				fmt.Sprintf(badIdentifierErrTemplate, "dir/Android.bp:4:11",
-					"lib1", "PY3", "a/b/c/-e/f/file1.py", "-e"),
+					"lib1", "a/b/c/-e/f/file1.py", "-e"),
 				fmt.Sprintf(badIdentifierErrTemplate, "dir/Android.bp:4:11",
-					"lib1", "PY3", "a/b/c/.file1.py", ".file1"),
+					"lib1", "a/b/c/.file1.py", ".file1"),
 				fmt.Sprintf(badIdentifierErrTemplate, "dir/Android.bp:4:11",
-					"lib1", "PY3", "a/b/c/123/file1.py", "123"),
+					"lib1", "a/b/c/123/file1.py", "123"),
 			},
 		},
 		{
@@ -219,115 +202,15 @@ var (
 			},
 			errors: []string{
 				fmt.Sprintf(dupRunfileErrTemplate, "dir/Android.bp:20:6",
-					"bin", "PY3", "a/b/c/file1.py", "bin", "dir/file1.py",
+					"bin", "a/b/c/file1.py", "bin", "dir/file1.py",
 					"lib1", "dir/c/file1.py"),
 			},
 		},
-		{
-			desc: "module for testing dependencies",
-			mockFiles: map[string][]byte{
-				filepath.Join("dir", bpFile): []byte(
-					`python_defaults {
-						name: "default_lib",
-						srcs: [
-							"default.py",
-						],
-						version: {
-							py2: {
-								enabled: true,
-								srcs: [
-									"default_py2.py",
-								],
-							},
-							py3: {
-								enabled: false,
-								srcs: [
-									"default_py3.py",
-								],
-							},
-						},
-					}
-
-					python_library_host {
-						name: "lib5",
-						pkg_path: "a/b/",
-						srcs: [
-							"file1.py",
-						],
-						version: {
-							py2: {
-								enabled: true,
-							},
-							py3: {
-								enabled: true,
-							},
-						},
-					}
-
-					python_library_host {
-						name: "lib6",
-						pkg_path: "c/d/",
-						srcs: [
-							"file2.py",
-						],
-						libs: [
-							"lib5",
-						],
-					}
-
-					python_binary_host {
-						name: "bin",
-						defaults: ["default_lib"],
-						pkg_path: "e/",
-						srcs: [
-							"bin.py",
-						],
-						libs: [
-							"lib5",
-						],
-						version: {
-							py3: {
-								enabled: true,
-								srcs: [
-									"file4.py",
-								],
-								libs: [
-									"lib6",
-								],
-							},
-						},
-					}`,
-				),
-				filepath.Join("dir", "default.py"):     nil,
-				filepath.Join("dir", "default_py2.py"): nil,
-				filepath.Join("dir", "default_py3.py"): nil,
-				filepath.Join("dir", "file1.py"):       nil,
-				filepath.Join("dir", "file2.py"):       nil,
-				filepath.Join("dir", "bin.py"):         nil,
-				filepath.Join("dir", "file4.py"):       nil,
-			},
-			expectedBinaries: []pyModule{
-				{
-					name:          "bin",
-					actualVersion: "PY3",
-					pyRunfiles: []string{
-						"e/default.py",
-						"e/bin.py",
-						"e/default_py3.py",
-						"e/file4.py",
-					},
-					srcsZip: "out/soong/.intermediates/dir/bin/PY3/bin.py.srcszip",
-				},
-			},
-		},
 	}
 )
 
 func TestPythonModule(t *testing.T) {
 	for _, d := range data {
-		if d.desc != "module with duplicate runfile path" {
-			continue
-		}
 		d.mockFiles[filepath.Join("common", bpFile)] = []byte(`
 python_library {
   name: "py3-stdlib",
@@ -416,10 +299,6 @@ func TestInvalidTestOnlyTargets(t *testing.T) {
 	for i, bp := range testCases {
 		ctx := android.GroupFixturePreparers(
 			PrepareForTestWithPythonBuildComponents,
-			android.FixtureRegisterWithContext(func(ctx android.RegistrationContext) {
-
-				ctx.RegisterModuleType("python_defaults", DefaultsFactory)
-			}),
 			android.PrepareForTestWithAllowMissingDependencies).
 			ExtendWithErrorHandler(android.FixtureIgnoreErrors).
 			RunTestWithBp(t, bp)
diff --git a/python/testing.go b/python/testing.go
index ce1a5ab27..fe53ee528 100644
--- a/python/testing.go
+++ b/python/testing.go
@@ -20,5 +20,4 @@ var PrepareForTestWithPythonBuildComponents = android.GroupFixturePreparers(
 	android.FixtureRegisterWithContext(registerPythonBinaryComponents),
 	android.FixtureRegisterWithContext(registerPythonLibraryComponents),
 	android.FixtureRegisterWithContext(registerPythonTestComponents),
-	android.FixtureRegisterWithContext(registerPythonMutators),
 )