Change bp2build converter of module "package".

1) Use attribute name "default_package_metadata" instead of
   "default_applicable_licenses" in packages to better describe its use.
2) Add a filegroup "default_metadata_file" in packages to search for
   METADATA file in each package.
3) Include "default_metadata_file" in each package's
   "default_package_metadata" attribute.

Bug: 275472038
Test: CIs
Change-Id: I645c013c39e3190fd96c4a549d39a331aced16bd

android/filegroup.go

@@ -76,6 +76,7 @@ func isFilegroupWithPattern(pattern *regexp.Regexp) bazel.LabelMapper {
 // https://docs.bazel.build/versions/master/be/general.html#filegroup
 type bazelFilegroupAttributes struct {
 	Srcs                bazel.LabelListAttribute
+	Applicable_licenses bazel.LabelListAttribute
 }
 
 type bazelAidlLibraryAttributes struct {

android/package.go

@@ -15,6 +15,8 @@
 package android
 
 import (
+	"path/filepath"
+
 	"android/soong/bazel"
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
@@ -40,7 +42,7 @@ type packageProperties struct {
 
 type bazelPackageAttributes struct {
 	Default_visibility       []string
-	Default_applicable_licenses bazel.LabelListAttribute
+	Default_package_metadata bazel.LabelListAttribute
 }
 
 type packageModule struct {
@@ -53,13 +55,32 @@ type packageModule struct {
 var _ Bazelable = &packageModule{}
 
 func (p *packageModule) ConvertWithBp2build(ctx TopDownMutatorContext) {
+	defaultPackageMetadata := bazel.MakeLabelListAttribute(BazelLabelForModuleDeps(ctx, p.properties.Default_applicable_licenses))
+	// If METADATA file exists in the package, add it to package(default_package_metadata=) using a
+	// filegroup(name="default_metadata_file") which can be accessed later on each module in Bazel
+	// using attribute "applicable_licenses".
+	// Attribute applicable_licenses of filegroup "default_metadata_file" has to be set to [],
+	// otherwise Bazel reports cyclic reference error.
+	if existed, _, _ := ctx.Config().fs.Exists(filepath.Join(ctx.ModuleDir(), "METADATA")); existed {
+		ctx.CreateBazelTargetModule(
+			bazel.BazelTargetModuleProperties{
+				Rule_class: "filegroup",
+			},
+			CommonAttributes{Name: "default_metadata_file"},
+			&bazelFilegroupAttributes{
+				Srcs:                bazel.MakeLabelListAttribute(BazelLabelForModuleSrc(ctx, []string{"METADATA"})),
+				Applicable_licenses: bazel.LabelListAttribute{Value: bazel.LabelList{Includes: []bazel.Label{}}, EmitEmptyList: true},
+			})
+		defaultPackageMetadata.Value.Add(&bazel.Label{Label: ":default_metadata_file"})
+	}
+
 	ctx.CreateBazelTargetModule(
 		bazel.BazelTargetModuleProperties{
 			Rule_class: "package",
 		},
 		CommonAttributes{},
 		&bazelPackageAttributes{
-			Default_applicable_licenses: bazel.MakeLabelListAttribute(BazelLabelForModuleDeps(ctx, p.properties.Default_applicable_licenses)),
+			Default_package_metadata: defaultPackageMetadata,
 			// FIXME(asmundak): once b/221436821 is resolved
 			Default_visibility: []string{"//visibility:public"},
 		})

bp2build/package_conversion_test.go

@@ -15,9 +15,10 @@
 package bp2build
 
 import (
+	"testing"
+
 	"android/soong/android"
 	"android/soong/genrule"
-	"testing"
 )
 
 func registerDependentModules(ctx android.RegistrationContext) {
@@ -29,6 +30,7 @@ func TestPackage(t *testing.T) {
 	tests := []struct {
 		description string
 		modules     string
+		fs          map[string]string
 		expected    []ExpectedRuleTarget
 	}{
 		{
@@ -50,7 +52,7 @@ package {
 					"package",
 					"",
 					AttrNameToString{
-						"default_applicable_licenses": `[":my_license"]`,
+						"default_package_metadata": `[":my_license"]`,
 						"default_visibility":       `["//visibility:public"]`,
 					},
 					android.HostAndDeviceDefault,
@@ -67,6 +69,57 @@ package {
 				},
 			},
 		},
+		{
+			description: "package has METADATA file",
+			fs: map[string]string{
+				"METADATA": ``,
+			},
+			modules: `
+license {
+  name: "my_license",
+  visibility: [":__subpackages__"],
+  license_kinds: ["SPDX-license-identifier-Apache-2.0"],
+  license_text: ["NOTICE"],
+}
+
+package {
+  default_applicable_licenses: ["my_license"],
+}
+`,
+			expected: []ExpectedRuleTarget{
+				{
+					"package",
+					"",
+					AttrNameToString{
+						"default_package_metadata": `[
+        ":my_license",
+        ":default_metadata_file",
+    ]`,
+						"default_visibility": `["//visibility:public"]`,
+					},
+					android.HostAndDeviceDefault,
+				},
+				{
+					"android_license",
+					"my_license",
+					AttrNameToString{
+						"license_kinds": `["SPDX-license-identifier-Apache-2.0"]`,
+						"license_text":  `"NOTICE"`,
+						"visibility":    `[":__subpackages__"]`,
+					},
+					android.HostAndDeviceDefault,
+				},
+				{
+					"filegroup",
+					"default_metadata_file",
+					AttrNameToString{
+						"applicable_licenses": `[]`,
+						"srcs":                `["METADATA"]`,
+					},
+					android.HostAndDeviceDefault,
+				},
+			},
+		},
 	}
 	for _, test := range tests {
 		expected := make([]string, 0, len(test.expected))
@@ -80,6 +133,7 @@ package {
 				ModuleTypeUnderTestFactory: android.PackageFactory,
 				Blueprint:                  test.modules,
 				ExpectedBazelTargets:       expected,
+				Filesystem:                 test.fs,
 			})
 	}
 }

ui/build/finder.go

@@ -87,6 +87,8 @@ func NewSourceFinder(ctx Context, config Config) (f *finder.Finder) {
 			"TEST_MAPPING",
 			// Bazel top-level file to mark a directory as a Bazel workspace.
 			"WORKSPACE",
+			// METADATA file of packages
+			"METADATA",
 		},
 		// Bazel Starlark configuration files and all .mk files for product/board configuration.
 		IncludeSuffixes: []string{".bzl", ".mk"},
@@ -189,6 +191,13 @@ func FindSources(ctx Context, config Config, f *finder.Finder) {
 		ctx.Fatalf("Could not find OWNERS: %v", err)
 	}
 
+	// Recursively look for all METADATA files.
+	metadataFiles := f.FindNamedAt(".", "METADATA")
+	err = dumpListToFile(ctx, config, metadataFiles, filepath.Join(dumpDir, "METADATA.list"))
+	if err != nil {
+		ctx.Fatalf("Could not find METADATA: %v", err)
+	}
+
 	// Recursively look for all TEST_MAPPING files.
 	testMappings := f.FindNamedAt(".", "TEST_MAPPING")
 	err = dumpListToFile(ctx, config, testMappings, filepath.Join(dumpDir, "TEST_MAPPING.list"))

ui/build/soong.go

@@ -400,6 +400,8 @@ func bootstrapBlueprint(ctx Context, config Config) {
 			pbi.Inputs = append(pbi.Inputs,
 				config.Bp2BuildFilesMarkerFile(),
 				filepath.Join(config.FileListDir(), "bazel.list"))
+		case bp2buildFilesTag:
+			pbi.Inputs = append(pbi.Inputs, filepath.Join(config.FileListDir(), "METADATA.list"))
 		}
 		invocations = append(invocations, pbi)
 	}