Implement bp2build for the package module

* We are interested mostly in the conversion the `default_applicable_licenses`
  attribute, as `default_visibility` cannot be handled until every module's
  `visibility` is handled.
* Several referenced license modules had to be manually enabled for
  conversion, and likewise a few trivial Android.bp containing only
  package and license modules.
* As Bazel allows only a single `package` rule, the package rules in a
  manually converted BUILD.bazel files were removed (in
  external/protobuf and prebuilts/clang/host/linux-x86 trees).
* The converted package rule is emitted before the `load` statements per
  Bazel documentation.

Bug: 190817312
Test: treehugger
Change-Id: If8bf6fee1580177de3bb402923615bcd48923ed2

android/allowlists/allowlists.go

@@ -37,6 +37,7 @@ const (
 
 var (
 	Bp2buildDefaultConfig = Bp2BuildConfig{
+		"art":                                   Bp2BuildDefaultTrue,
 		"art/libartbase":                        Bp2BuildDefaultTrueRecursively,
 		"art/libartpalette":                     Bp2BuildDefaultTrueRecursively,
 		"art/libdexfile":                        Bp2BuildDefaultTrueRecursively,
@@ -54,6 +55,7 @@ var (
 		"build/soong/cc/libbuildversion":     Bp2BuildDefaultTrue, // Skip tests subdir
 		"build/soong/cc/ndkstubgen":          Bp2BuildDefaultTrue,
 		"build/soong/cc/symbolfile":          Bp2BuildDefaultTrue,
+		"build/soong/licenses":               Bp2BuildDefaultTrue,
 		"build/soong/linkerconfig":           Bp2BuildDefaultTrueRecursively,
 		"build/soong/scripts":                Bp2BuildDefaultTrueRecursively,
 
@@ -98,6 +100,7 @@ var (
 		"external/aac":                           Bp2BuildDefaultTrueRecursively,
 		"external/arm-optimized-routines":        Bp2BuildDefaultTrueRecursively,
 		"external/auto/android-annotation-stubs": Bp2BuildDefaultTrueRecursively,
+		"external/auto":                          Bp2BuildDefaultTrue,
 		"external/auto/common":                   Bp2BuildDefaultTrueRecursively,
 		"external/auto/service":                  Bp2BuildDefaultTrueRecursively,
 		"external/boringssl":                     Bp2BuildDefaultTrueRecursively,
@@ -232,6 +235,7 @@ var (
 		"prebuilts/runtime/mainline/platform/sdk":  Bp2BuildDefaultTrueRecursively,
 		"prebuilts/sdk/current/extras/app-toolkit": Bp2BuildDefaultTrue,
 		"prebuilts/sdk/current/support":            Bp2BuildDefaultTrue,
+		"prebuilts/tools":                          Bp2BuildDefaultTrue,
 		"prebuilts/tools/common/m2":                Bp2BuildDefaultTrue,
 
 		"system/apex":                                            Bp2BuildDefaultFalse, // TODO(b/207466993): flaky failures
@@ -273,6 +277,7 @@ var (
 		"system/libprocinfo":                                     Bp2BuildDefaultTrue,
 		"system/libziparchive":                                   Bp2BuildDefaultTrueRecursively,
 		"system/logging":                                         Bp2BuildDefaultTrueRecursively,
+		"system/media":                                           Bp2BuildDefaultTrue,
 		"system/media/audio":                                     Bp2BuildDefaultTrueRecursively,
 		"system/media/audio_utils":                               Bp2BuildDefaultTrueRecursively,
 		"system/memory/libion":                                   Bp2BuildDefaultTrueRecursively,
@@ -492,6 +497,7 @@ var (
 	}
 
 	Bp2buildModuleTypeAlwaysConvertList = []string{
+		"license",
 		"linker_config",
 		"java_import",
 		"java_import_host",

android/license.go

@@ -78,9 +78,11 @@ func (m *licenseModule) ConvertWithBp2build(ctx TopDownMutatorContext) {
 		Visibility:       m.properties.Visibility,
 	}
 
-	// TODO(asmundak): Soong supports multiple license texts while Bazel does not.
-	if len(m.properties.License_text) > 1 {
-		fmt.Fprintf(os.Stderr, "%s:%s: warning: using only the first license_text item\n",
+	// TODO(asmundak): Soong supports multiple license texts while Bazel's license
+	// rule does not. Have android_license create a genrule to concatenate multiple
+	// license texts.
+	if len(m.properties.License_text) > 1 && ctx.Config().IsEnvTrue("BP2BUILD_VERBOSE") {
+		fmt.Fprintf(os.Stderr, "warning: using only the first license_text item from //%s:%s\n",
 			ctx.ModuleDir(), m.Name())
 	}
 	if len(m.properties.License_text) >= 1 {

android/package.go

@@ -15,6 +15,7 @@
 package android
 
 import (
+	"android/soong/bazel"
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
@@ -37,12 +38,33 @@ type packageProperties struct {
 	Default_applicable_licenses []string
 }
 
+type bazelPackageAttributes struct {
+	Default_visibility          []string
+	Default_applicable_licenses bazel.LabelListAttribute
+}
+
 type packageModule struct {
 	ModuleBase
+	BazelModuleBase
 
 	properties packageProperties
 }
 
+var _ Bazelable = &packageModule{}
+
+func (p *packageModule) ConvertWithBp2build(ctx TopDownMutatorContext) {
+	ctx.CreateBazelTargetModule(
+		bazel.BazelTargetModuleProperties{
+			Rule_class: "package",
+		},
+		CommonAttributes{},
+		&bazelPackageAttributes{
+			Default_applicable_licenses: bazel.MakeLabelListAttribute(BazelLabelForModuleDeps(ctx, p.properties.Default_applicable_licenses)),
+			// FIXME(asmundak): once b/221436821 is resolved
+			Default_visibility: []string{"//visibility:public"},
+		})
+}
+
 func (p *packageModule) GenerateAndroidBuildActions(ModuleContext) {
 	// Nothing to do.
 }
@@ -59,7 +81,7 @@ func (p *packageModule) qualifiedModuleId(ctx BaseModuleContext) qualifiedModule
 func PackageFactory() Module {
 	module := &packageModule{}
 
-	module.AddProperties(&module.properties)
+	module.AddProperties(&module.properties, &module.commonProperties.BazelConversionStatus)
 
 	// The name is the relative path from build root to the directory containing this
 	// module. Set that name at the earliest possible moment that information is available
@@ -76,5 +98,7 @@ func PackageFactory() Module {
 	// its checking and parsing phases so make it the primary licenses property.
 	setPrimaryLicensesProperty(module, "default_applicable_licenses", &module.properties.Default_applicable_licenses)
 
+	InitBazelModule(module)
+
 	return module
 }

bp2build/Android.bp

@@ -67,6 +67,7 @@ bootstrap_go_package {
         "license_kind_conversion_test.go",
         "linker_config_conversion_test.go",
         "ndk_headers_conversion_test.go",
+        "package_conversion_test.go",
         "performance_test.go",
         "prebuilt_etc_conversion_test.go",
         "python_binary_conversion_test.go",

bp2build/build_conversion.go

@@ -64,7 +64,16 @@ func (t BazelTarget) Label() string {
 // BazelTargets is a typedef for a slice of BazelTarget objects.
 type BazelTargets []BazelTarget
 
-// sort a list of BazelTargets in-place by name
+func (targets BazelTargets) packageRule() *BazelTarget {
+	for _, target := range targets {
+		if target.ruleClass == "package" {
+			return &target
+		}
+	}
+	return nil
+}
+
+// sort a list of BazelTargets in-place, by name, and by generated/handcrafted types.
 func (targets BazelTargets) sort() {
 	sort.Slice(targets, func(i, j int) bool {
 		return targets[i].name < targets[j].name
@@ -77,7 +86,9 @@ func (targets BazelTargets) sort() {
 func (targets BazelTargets) String() string {
 	var res string
 	for i, target := range targets {
+		if target.ruleClass != "package" {
 			res += target.content
+		}
 		if i != len(targets)-1 {
 			res += "\n\n"
 		}

bp2build/conversion.go

@@ -96,10 +96,14 @@ func createBuildFiles(buildToTargets map[string]BazelTargets, mode CodegenMode)
 # This file was automatically generated by bp2build for the Bazel migration project.
 # Feel free to edit or test it, but do *not* check it into your version control system.
 `
-
-			// Hardcode the default visibility.
-			content += "package(default_visibility = [\"//visibility:public\"])\n"
 			content += targets.LoadStatements()
+			content += "\n\n"
+			// Get package rule from the handcrafted BUILD file, otherwise emit the default one.
+			prText := "package(default_visibility = [\"//visibility:public\"])\n"
+			if pr := targets.packageRule(); pr != nil {
+				prText = pr.content
+			}
+			content += prText
 		} else if mode == QueryView {
 			content = soongModuleLoad
 		}
@@ -160,7 +164,7 @@ func shouldSkipStructField(field reflect.StructField) bool {
 		// internal to Soong only, and these fields do not have PkgPath.
 		return true
 	}
-	// fields with tag `blueprint:"mutated"` are exported to enable modification in mutators, etc
+	// fields with tag `blueprint:"mutated"` are exported to enable modification in mutators, etc.
 	// but cannot be set in a .bp file
 	if proptools.HasTag(field, "blueprint", "mutated") {
 		return true

bp2build/package_conversion_test.go

@@ -0,0 +1,85 @@
+// Copyright 2022 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package bp2build
+
+import (
+	"android/soong/android"
+	"android/soong/genrule"
+	"testing"
+)
+
+func registerDependentModules(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("license", android.LicenseFactory)
+	ctx.RegisterModuleType("genrule", genrule.GenRuleFactory)
+}
+
+func TestPackage(t *testing.T) {
+	tests := []struct {
+		description string
+		modules     string
+		expected    []ExpectedRuleTarget
+	}{
+		{
+			description: "with default applicable licenses",
+			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_applicable_licenses": `[":my_license"]`,
+						"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,
+				},
+			},
+		},
+	}
+	for _, test := range tests {
+		expected := make([]string, 0, len(test.expected))
+		for _, e := range test.expected {
+			expected = append(expected, e.String())
+		}
+		RunBp2BuildTestCase(t, registerDependentModules,
+			Bp2buildTestCase{
+				Description:                test.description,
+				ModuleTypeUnderTest:        "package",
+				ModuleTypeUnderTestFactory: android.PackageFactory,
+				Blueprint:                  test.modules,
+				ExpectedBazelTargets:       expected,
+			})
+	}
+}

tests/lib.sh

@@ -123,6 +123,7 @@ function create_mock_bazel {
   symlink_directory prebuilts/jdk
   symlink_directory external/bazel-skylib
   symlink_directory external/bazelbuild-rules_android
+  symlink_directory external/bazelbuild-rules_license
   symlink_directory external/bazelbuild-kotlin-rules
 
   symlink_file WORKSPACE