Refactor queryview.

Splits queryview into queryview and bp2build. The latter runs as a
presingleton (could be converted to a singleton). This prevents needing
to run soong_ui a subsequent time to build the query. Queryview remains
as a separate step to prevent increasing runtime due to this generation
every time Soong runs.

Currently this is running as a presingleton as this gives a translation
of Android.bp files after only LoadHooks have run, no mutators.

Test: go tests
Test: m queryview && bazel query --config=queryview //...
Change-Id: If2ba28c7ef60fbd41f43bda6623d41c8c7d23a1b

10 files changed, 1515 insertions, 0 deletions

diff --git a/bp2build/Android.bp b/bp2build/Android.bp
new file mode 100644
index 000000000..49587f488
--- /dev/null
+++ b/bp2build/Android.bp
@@ -0,0 +1,23 @@
+bootstrap_go_package {
+    name: "soong-bp2build",
+    pkgPath: "android/soong/bp2build",
+    srcs: [
+        "androidbp_to_build_templates.go",
+        "bp2build.go",
+        "build_conversion.go",
+        "bzl_conversion.go",
+        "conversion.go",
+    ],
+    deps: [
+        "soong-android",
+    ],
+    testSrcs: [
+        "build_conversion_test.go",
+        "bzl_conversion_test.go",
+        "conversion_test.go",
+        "testing.go",
+    ],
+    pluginFor: [
+        "soong_build",
+    ],
+}
diff --git a/bp2build/androidbp_to_build_templates.go b/bp2build/androidbp_to_build_templates.go
new file mode 100644
index 000000000..75c3ccb9a
--- /dev/null
+++ b/bp2build/androidbp_to_build_templates.go
@@ -0,0 +1,124 @@
+// Copyright 2020 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
+
+const (
+	// The default `load` preamble for every generated BUILD file.
+	soongModuleLoad = `package(default_visibility = ["//visibility:public"])
+load("//build/bazel/queryview_rules:soong_module.bzl", "soong_module")
+
+`
+
+	// A macro call in the BUILD file representing a Soong module, with space
+	// for expanding more attributes.
+	soongModuleTarget = `soong_module(
+    name = "%s",
+    module_name = "%s",
+    module_type = "%s",
+    module_variant = "%s",
+    module_deps = %s,
+%s)`
+
+	// A simple provider to mark and differentiate Soong module rule shims from
+	// regular Bazel rules. Every Soong module rule shim returns a
+	// SoongModuleInfo provider, and can only depend on rules returning
+	// SoongModuleInfo in the `module_deps` attribute.
+	providersBzl = `SoongModuleInfo = provider(
+    fields = {
+        "name": "Name of module",
+        "type": "Type of module",
+        "variant": "Variant of module",
+    },
+)
+`
+
+	// The soong_module rule implementation in a .bzl file.
+	soongModuleBzl = `
+%s
+
+load("//build/bazel/queryview_rules:providers.bzl", "SoongModuleInfo")
+
+def _generic_soong_module_impl(ctx):
+    return [
+        SoongModuleInfo(
+            name = ctx.attr.module_name,
+            type = ctx.attr.module_type,
+            variant = ctx.attr.module_variant,
+        ),
+    ]
+
+generic_soong_module = rule(
+    implementation = _generic_soong_module_impl,
+    attrs = {
+        "module_name": attr.string(mandatory = True),
+        "module_type": attr.string(mandatory = True),
+        "module_variant": attr.string(),
+        "module_deps": attr.label_list(providers = [SoongModuleInfo]),
+    },
+)
+
+soong_module_rule_map = {
+%s}
+
+_SUPPORTED_TYPES = ["bool", "int", "string"]
+
+def _is_supported_type(value):
+    if type(value) in _SUPPORTED_TYPES:
+        return True
+    elif type(value) == "list":
+        supported = True
+        for v in value:
+            supported = supported and type(v) in _SUPPORTED_TYPES
+        return supported
+    else:
+        return False
+
+# soong_module is a macro that supports arbitrary kwargs, and uses module_type to
+# expand to the right underlying shim.
+def soong_module(name, module_type, **kwargs):
+    soong_module_rule = soong_module_rule_map.get(module_type)
+
+    if soong_module_rule == None:
+        # This module type does not have an existing rule to map to, so use the
+        # generic_soong_module rule instead.
+        generic_soong_module(
+            name = name,
+            module_type = module_type,
+            module_name = kwargs.pop("module_name", ""),
+            module_variant = kwargs.pop("module_variant", ""),
+            module_deps = kwargs.pop("module_deps", []),
+        )
+    else:
+        supported_kwargs = dict()
+        for key, value in kwargs.items():
+            if _is_supported_type(value):
+                supported_kwargs[key] = value
+        soong_module_rule(
+            name = name,
+            **supported_kwargs,
+        )
+`
+
+	// A rule shim for representing a Soong module type and its properties.
+	moduleRuleShim = `
+def _%[1]s_impl(ctx):
+    return [SoongModuleInfo()]
+
+%[1]s = rule(
+    implementation = _%[1]s_impl,
+    attrs = %[2]s
+)
+`
+)
diff --git a/bp2build/bp2build.go b/bp2build/bp2build.go
new file mode 100644
index 000000000..30f298a0c
--- /dev/null
+++ b/bp2build/bp2build.go
@@ -0,0 +1,77 @@
+// Copyright 2020 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"
+	"os"
+)
+
+// The Bazel bp2build singleton is responsible for writing .bzl files that are equivalent to
+// Android.bp files that are capable of being built with Bazel.
+func init() {
+	android.RegisterBazelConverterPreSingletonType("androidbp_to_build", AndroidBpToBuildSingleton)
+}
+
+func AndroidBpToBuildSingleton() android.Singleton {
+	return &androidBpToBuildSingleton{
+		name: "bp2build",
+	}
+}
+
+type androidBpToBuildSingleton struct {
+	name      string
+	outputDir android.OutputPath
+}
+
+func (s *androidBpToBuildSingleton) GenerateBuildActions(ctx android.SingletonContext) {
+	s.outputDir = android.PathForOutput(ctx, s.name)
+	android.RemoveAllOutputDir(s.outputDir)
+
+	if !ctx.Config().IsEnvTrue("CONVERT_TO_BAZEL") {
+		return
+	}
+
+	ruleShims := CreateRuleShims(android.ModuleTypeFactories())
+
+	buildToTargets := GenerateSoongModuleTargets(ctx)
+
+	filesToWrite := CreateBazelFiles(ruleShims, buildToTargets)
+	for _, f := range filesToWrite {
+		if err := s.writeFile(ctx, f); err != nil {
+			ctx.Errorf("Failed to write %q (dir %q) due to %q", f.Basename, f.Dir, err)
+		}
+	}
+}
+
+func (s *androidBpToBuildSingleton) getOutputPath(ctx android.PathContext, dir string) android.OutputPath {
+	return s.outputDir.Join(ctx, dir)
+}
+
+func (s *androidBpToBuildSingleton) writeFile(ctx android.PathContext, f BazelFile) error {
+	return writeReadOnlyFile(ctx, s.getOutputPath(ctx, f.Dir), f.Basename, f.Contents)
+}
+
+// The auto-conversion directory should be read-only, sufficient for bazel query. The files
+// are not intended to be edited by end users.
+func writeReadOnlyFile(ctx android.PathContext, dir android.OutputPath, baseName, content string) error {
+	android.CreateOutputDirIfNonexistent(dir, os.ModePerm)
+	pathToFile := dir.Join(ctx, baseName)
+
+	// 0444 is read-only
+	err := android.WriteFileToOutputDir(pathToFile, []byte(content), 0444)
+
+	return err
+}
diff --git a/bp2build/build_conversion.go b/bp2build/build_conversion.go
new file mode 100644
index 000000000..03296852f
--- /dev/null
+++ b/bp2build/build_conversion.go
@@ -0,0 +1,305 @@
+// Copyright 2020 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"
+	"fmt"
+	"reflect"
+	"strings"
+
+	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
+)
+
+type BazelAttributes struct {
+	Attrs map[string]string
+}
+
+type BazelTarget struct {
+	name    string
+	content string
+}
+
+type bpToBuildContext interface {
+	ModuleName(module blueprint.Module) string
+	ModuleDir(module blueprint.Module) string
+	ModuleSubDir(module blueprint.Module) string
+	ModuleType(module blueprint.Module) string
+
+	VisitAllModulesBlueprint(visit func(blueprint.Module))
+	VisitDirectDeps(module android.Module, visit func(android.Module))
+}
+
+// props is an unsorted map. This function ensures that
+// the generated attributes are sorted to ensure determinism.
+func propsToAttributes(props map[string]string) string {
+	var attributes string
+	for _, propName := range android.SortedStringKeys(props) {
+		if shouldGenerateAttribute(propName) {
+			attributes += fmt.Sprintf("    %s = %s,\n", propName, props[propName])
+		}
+	}
+	return attributes
+}
+
+func GenerateSoongModuleTargets(ctx bpToBuildContext) map[string][]BazelTarget {
+	buildFileToTargets := make(map[string][]BazelTarget)
+	ctx.VisitAllModulesBlueprint(func(m blueprint.Module) {
+		dir := ctx.ModuleDir(m)
+		t := generateSoongModuleTarget(ctx, m)
+		buildFileToTargets[ctx.ModuleDir(m)] = append(buildFileToTargets[dir], t)
+	})
+	return buildFileToTargets
+}
+
+// Convert a module and its deps and props into a Bazel macro/rule
+// representation in the BUILD file.
+func generateSoongModuleTarget(ctx bpToBuildContext, m blueprint.Module) BazelTarget {
+	props := getBuildProperties(ctx, m)
+
+	// TODO(b/163018919): DirectDeps can have duplicate (module, variant)
+	// items, if the modules are added using different DependencyTag. Figure
+	// out the implications of that.
+	depLabels := map[string]bool{}
+	if aModule, ok := m.(android.Module); ok {
+		ctx.VisitDirectDeps(aModule, func(depModule android.Module) {
+			depLabels[qualifiedTargetLabel(ctx, depModule)] = true
+		})
+	}
+	attributes := propsToAttributes(props.Attrs)
+
+	depLabelList := "[\n"
+	for depLabel, _ := range depLabels {
+		depLabelList += fmt.Sprintf("        %q,\n", depLabel)
+	}
+	depLabelList += "    ]"
+
+	targetName := targetNameWithVariant(ctx, m)
+	return BazelTarget{
+		name: targetName,
+		content: fmt.Sprintf(
+			soongModuleTarget,
+			targetName,
+			ctx.ModuleName(m),
+			canonicalizeModuleType(ctx.ModuleType(m)),
+			ctx.ModuleSubDir(m),
+			depLabelList,
+			attributes),
+	}
+}
+
+func getBuildProperties(ctx bpToBuildContext, m blueprint.Module) BazelAttributes {
+	var allProps map[string]string
+	// TODO: this omits properties for blueprint modules (blueprint_go_binary,
+	// bootstrap_go_binary, bootstrap_go_package), which will have to be handled separately.
+	if aModule, ok := m.(android.Module); ok {
+		allProps = ExtractModuleProperties(aModule)
+	}
+
+	return BazelAttributes{
+		Attrs: allProps,
+	}
+}
+
+// Generically extract module properties and types into a map, keyed by the module property name.
+func ExtractModuleProperties(aModule android.Module) map[string]string {
+	ret := map[string]string{}
+
+	// Iterate over this android.Module's property structs.
+	for _, properties := range aModule.GetProperties() {
+		propertiesValue := reflect.ValueOf(properties)
+		// Check that propertiesValue is a pointer to the Properties struct, like
+		// *cc.BaseLinkerProperties or *java.CompilerProperties.
+		//
+		// propertiesValue can also be type-asserted to the structs to
+		// manipulate internal props, if needed.
+		if isStructPtr(propertiesValue.Type()) {
+			structValue := propertiesValue.Elem()
+			for k, v := range extractStructProperties(structValue, 0) {
+				ret[k] = v
+			}
+		} else {
+			panic(fmt.Errorf(
+				"properties must be a pointer to a struct, got %T",
+				propertiesValue.Interface()))
+		}
+	}
+
+	return ret
+}
+
+func isStructPtr(t reflect.Type) bool {
+	return t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct
+}
+
+// prettyPrint a property value into the equivalent Starlark representation
+// recursively.
+func prettyPrint(propertyValue reflect.Value, indent int) (string, error) {
+	if isZero(propertyValue) {
+		// A property value being set or unset actually matters -- Soong does set default
+		// values for unset properties, like system_shared_libs = ["libc", "libm", "libdl"] at
+		// https://cs.android.com/android/platform/superproject/+/master:build/soong/cc/linker.go;l=281-287;drc=f70926eef0b9b57faf04c17a1062ce50d209e480
+		//
+		// In Bazel-parlance, we would use "attr.<type>(default = <default value>)" to set the default
+		// value of unset attributes.
+		return "", nil
+	}
+
+	var ret string
+	switch propertyValue.Kind() {
+	case reflect.String:
+		ret = fmt.Sprintf("\"%v\"", escapeString(propertyValue.String()))
+	case reflect.Bool:
+		ret = strings.Title(fmt.Sprintf("%v", propertyValue.Interface()))
+	case reflect.Int, reflect.Uint, reflect.Int64:
+		ret = fmt.Sprintf("%v", propertyValue.Interface())
+	case reflect.Ptr:
+		return prettyPrint(propertyValue.Elem(), indent)
+	case reflect.Slice:
+		ret = "[\n"
+		for i := 0; i < propertyValue.Len(); i++ {
+			indexedValue, err := prettyPrint(propertyValue.Index(i), indent+1)
+			if err != nil {
+				return "", err
+			}
+
+			if indexedValue != "" {
+				ret += makeIndent(indent + 1)
+				ret += indexedValue
+				ret += ",\n"
+			}
+		}
+		ret += makeIndent(indent)
+		ret += "]"
+	case reflect.Struct:
+		ret = "{\n"
+		// Sort and print the struct props by the key.
+		structProps := extractStructProperties(propertyValue, indent)
+		for _, k := range android.SortedStringKeys(structProps) {
+			ret += makeIndent(indent + 1)
+			ret += fmt.Sprintf("%q: %s,\n", k, structProps[k])
+		}
+		ret += makeIndent(indent)
+		ret += "}"
+	case reflect.Interface:
+		// TODO(b/164227191): implement pretty print for interfaces.
+		// Interfaces are used for for arch, multilib and target properties.
+		return "", nil
+	default:
+		return "", fmt.Errorf(
+			"unexpected kind for property struct field: %s", propertyValue.Kind())
+	}
+	return ret, nil
+}
+
+// Converts a reflected property struct value into a map of property names and property values,
+// which each property value correctly pretty-printed and indented at the right nest level,
+// since property structs can be nested. In Starlark, nested structs are represented as nested
+// dicts: https://docs.bazel.build/skylark/lib/dict.html
+func extractStructProperties(structValue reflect.Value, indent int) map[string]string {
+	if structValue.Kind() != reflect.Struct {
+		panic(fmt.Errorf("Expected a reflect.Struct type, but got %s", structValue.Kind()))
+	}
+
+	ret := map[string]string{}
+	structType := structValue.Type()
+	for i := 0; i < structValue.NumField(); i++ {
+		field := structType.Field(i)
+		if shouldSkipStructField(field) {
+			continue
+		}
+
+		fieldValue := structValue.Field(i)
+		if isZero(fieldValue) {
+			// Ignore zero-valued fields
+			continue
+		}
+
+		propertyName := proptools.PropertyNameForField(field.Name)
+		prettyPrintedValue, err := prettyPrint(fieldValue, indent+1)
+		if err != nil {
+			panic(
+				fmt.Errorf(
+					"Error while parsing property: %q. %s",
+					propertyName,
+					err))
+		}
+		if prettyPrintedValue != "" {
+			ret[propertyName] = prettyPrintedValue
+		}
+	}
+
+	return ret
+}
+
+func isZero(value reflect.Value) bool {
+	switch value.Kind() {
+	case reflect.Func, reflect.Map, reflect.Slice:
+		return value.IsNil()
+	case reflect.Array:
+		valueIsZero := true
+		for i := 0; i < value.Len(); i++ {
+			valueIsZero = valueIsZero && isZero(value.Index(i))
+		}
+		return valueIsZero
+	case reflect.Struct:
+		valueIsZero := true
+		for i := 0; i < value.NumField(); i++ {
+			if value.Field(i).CanSet() {
+				valueIsZero = valueIsZero && isZero(value.Field(i))
+			}
+		}
+		return valueIsZero
+	case reflect.Ptr:
+		if !value.IsNil() {
+			return isZero(reflect.Indirect(value))
+		} else {
+			return true
+		}
+	default:
+		zeroValue := reflect.Zero(value.Type())
+		result := value.Interface() == zeroValue.Interface()
+		return result
+	}
+}
+
+func escapeString(s string) string {
+	s = strings.ReplaceAll(s, "\\", "\\\\")
+	return strings.ReplaceAll(s, "\"", "\\\"")
+}
+
+func makeIndent(indent int) string {
+	if indent < 0 {
+		panic(fmt.Errorf("indent column cannot be less than 0, but got %d", indent))
+	}
+	return strings.Repeat("    ", indent)
+}
+
+func targetNameWithVariant(c bpToBuildContext, logicModule blueprint.Module) string {
+	name := ""
+	if c.ModuleSubDir(logicModule) != "" {
+		// TODO(b/162720883): Figure out a way to drop the "--" variant suffixes.
+		name = c.ModuleName(logicModule) + "--" + c.ModuleSubDir(logicModule)
+	} else {
+		name = c.ModuleName(logicModule)
+	}
+
+	return strings.Replace(name, "//", "", 1)
+}
+
+func qualifiedTargetLabel(c bpToBuildContext, logicModule blueprint.Module) string {
+	return fmt.Sprintf("//%s:%s", c.ModuleDir(logicModule), targetNameWithVariant(c, logicModule))
+}
diff --git a/bp2build/build_conversion_test.go b/bp2build/build_conversion_test.go
new file mode 100644
index 000000000..8230ad8c0
--- /dev/null
+++ b/bp2build/build_conversion_test.go
@@ -0,0 +1,221 @@
+// Copyright 2020 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"
+	"testing"
+)
+
+func TestGenerateSoongModuleTargets(t *testing.T) {
+	testCases := []struct {
+		bp                  string
+		expectedBazelTarget string
+	}{
+		{
+			bp: `custom {
+	name: "foo",
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+)`,
+		},
+		{
+			bp: `custom {
+	name: "foo",
+	ramdisk: true,
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+    ramdisk = True,
+)`,
+		},
+		{
+			bp: `custom {
+	name: "foo",
+	owner: "a_string_with\"quotes\"_and_\\backslashes\\\\",
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+    owner = "a_string_with\"quotes\"_and_\\backslashes\\\\",
+)`,
+		},
+		{
+			bp: `custom {
+	name: "foo",
+	required: ["bar"],
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+    required = [
+        "bar",
+    ],
+)`,
+		},
+		{
+			bp: `custom {
+	name: "foo",
+	target_required: ["qux", "bazqux"],
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+    target_required = [
+        "qux",
+        "bazqux",
+    ],
+)`,
+		},
+		{
+			bp: `custom {
+	name: "foo",
+	dist: {
+		targets: ["goal_foo"],
+		tag: ".foo",
+	},
+	dists: [
+		{
+			targets: ["goal_bar"],
+			tag: ".bar",
+		},
+	],
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+    dist = {
+        "tag": ".foo",
+        "targets": [
+            "goal_foo",
+        ],
+    },
+    dists = [
+        {
+            "tag": ".bar",
+            "targets": [
+                "goal_bar",
+            ],
+        },
+    ],
+)`,
+		},
+		{
+			bp: `custom {
+	name: "foo",
+	required: ["bar"],
+	target_required: ["qux", "bazqux"],
+	ramdisk: true,
+	owner: "custom_owner",
+	dists: [
+		{
+			tag: ".tag",
+			targets: ["my_goal"],
+		},
+	],
+}
+		`,
+			expectedBazelTarget: `soong_module(
+    name = "foo",
+    module_name = "foo",
+    module_type = "custom",
+    module_variant = "",
+    module_deps = [
+    ],
+    dists = [
+        {
+            "tag": ".tag",
+            "targets": [
+                "my_goal",
+            ],
+        },
+    ],
+    owner = "custom_owner",
+    ramdisk = True,
+    required = [
+        "bar",
+    ],
+    target_required = [
+        "qux",
+        "bazqux",
+    ],
+)`,
+		},
+	}
+
+	dir := "."
+	for _, testCase := range testCases {
+		config := android.TestConfig(buildDir, nil, testCase.bp, nil)
+		ctx := android.NewTestContext(config)
+		ctx.RegisterModuleType("custom", customModuleFactory)
+		ctx.Register()
+
+		_, errs := ctx.ParseFileList(dir, []string{"Android.bp"})
+		android.FailIfErrored(t, errs)
+		_, errs = ctx.PrepareBuildActions(config)
+		android.FailIfErrored(t, errs)
+
+		bp2BuildCtx := bp2buildBlueprintWrapContext{
+			bpCtx: ctx.Context.Context,
+		}
+
+		bazelTargets := GenerateSoongModuleTargets(&bp2BuildCtx)[dir]
+		if g, w := len(bazelTargets), 1; g != w {
+			t.Fatalf("Expected %d bazel target, got %d", w, g)
+		}
+
+		actualBazelTarget := bazelTargets[0]
+		if actualBazelTarget.content != testCase.expectedBazelTarget {
+			t.Errorf(
+				"Expected generated Bazel target to be '%s', got '%s'",
+				testCase.expectedBazelTarget,
+				actualBazelTarget,
+			)
+		}
+	}
+}
diff --git a/bp2build/bzl_conversion.go b/bp2build/bzl_conversion.go
new file mode 100644
index 000000000..04c45420b
--- /dev/null
+++ b/bp2build/bzl_conversion.go
@@ -0,0 +1,230 @@
+// Copyright 2020 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"
+	"fmt"
+	"reflect"
+	"runtime"
+	"sort"
+	"strings"
+
+	"github.com/google/blueprint/proptools"
+)
+
+var (
+	// An allowlist of prop types that are surfaced from module props to rule
+	// attributes. (nested) dictionaries are notably absent here, because while
+	// Soong supports multi value typed and nested dictionaries, Bazel's rule
+	// attr() API supports only single-level string_dicts.
+	allowedPropTypes = map[string]bool{
+		"int":         true, // e.g. 42
+		"bool":        true, // e.g. True
+		"string_list": true, // e.g. ["a", "b"]
+		"string":      true, // e.g. "a"
+	}
+)
+
+type rule struct {
+	name  string
+	attrs string
+}
+
+type RuleShim struct {
+	// The rule class shims contained in a bzl file. e.g. ["cc_object", "cc_library", ..]
+	rules []string
+
+	// The generated string content of the bzl file.
+	content string
+}
+
+// Create <module>.bzl containing Bazel rule shims for every module type available in Soong and
+// user-specified Go plugins.
+//
+// This function reuses documentation generation APIs to ensure parity between modules-as-docs
+// and modules-as-code, including the names and types of morule properties.
+func CreateRuleShims(moduleTypeFactories map[string]android.ModuleFactory) map[string]RuleShim {
+	ruleShims := map[string]RuleShim{}
+	for pkg, rules := range generateRules(moduleTypeFactories) {
+		shim := RuleShim{
+			rules: make([]string, 0, len(rules)),
+		}
+		shim.content = "load(\"//build/bazel/queryview_rules:providers.bzl\", \"SoongModuleInfo\")\n"
+
+		bzlFileName := strings.ReplaceAll(pkg, "android/soong/", "")
+		bzlFileName = strings.ReplaceAll(bzlFileName, ".", "_")
+		bzlFileName = strings.ReplaceAll(bzlFileName, "/", "_")
+
+		for _, r := range rules {
+			shim.content += fmt.Sprintf(moduleRuleShim, r.name, r.attrs)
+			shim.rules = append(shim.rules, r.name)
+		}
+		sort.Strings(shim.rules)
+		ruleShims[bzlFileName] = shim
+	}
+	return ruleShims
+}
+
+// Generate the content of soong_module.bzl with the rule shim load statements
+// and mapping of module_type to rule shim map for every module type in Soong.
+func generateSoongModuleBzl(bzlLoads map[string]RuleShim) string {
+	var loadStmts string
+	var moduleRuleMap string
+	for _, bzlFileName := range android.SortedStringKeys(bzlLoads) {
+		loadStmt := "load(\"//build/bazel/queryview_rules:"
+		loadStmt += bzlFileName
+		loadStmt += ".bzl\""
+		ruleShim := bzlLoads[bzlFileName]
+		for _, rule := range ruleShim.rules {
+			loadStmt += fmt.Sprintf(", %q", rule)
+			moduleRuleMap += "    \"" + rule + "\": " + rule + ",\n"
+		}
+		loadStmt += ")\n"
+		loadStmts += loadStmt
+	}
+
+	return fmt.Sprintf(soongModuleBzl, loadStmts, moduleRuleMap)
+}
+
+func generateRules(moduleTypeFactories map[string]android.ModuleFactory) map[string][]rule {
+	// TODO: add shims for bootstrap/blueprint go modules types
+
+	rules := make(map[string][]rule)
+	// TODO: allow registration of a bzl rule when registring a factory
+	for _, moduleType := range android.SortedStringKeys(moduleTypeFactories) {
+		factory := moduleTypeFactories[moduleType]
+		factoryName := runtime.FuncForPC(reflect.ValueOf(factory).Pointer()).Name()
+		pkg := strings.Split(factoryName, ".")[0]
+		attrs := `{
+        "module_name": attr.string(mandatory = True),
+        "module_variant": attr.string(),
+        "module_deps": attr.label_list(providers = [SoongModuleInfo]),
+`
+		attrs += getAttributes(factory)
+		attrs += "    },"
+
+		r := rule{
+			name:  canonicalizeModuleType(moduleType),
+			attrs: attrs,
+		}
+
+		rules[pkg] = append(rules[pkg], r)
+	}
+	return rules
+}
+
+type property struct {
+	name             string
+	starlarkAttrType string
+	properties       []property
+}
+
+const (
+	attributeIndent = "        "
+)
+
+func (p *property) attributeString() string {
+	if !shouldGenerateAttribute(p.name) {
+		return ""
+	}
+
+	if _, ok := allowedPropTypes[p.starlarkAttrType]; !ok {
+		// a struct -- let's just comment out sub-props
+		s := fmt.Sprintf(attributeIndent+"# %s start\n", p.name)
+		for _, nestedP := range p.properties {
+			s += "# " + nestedP.attributeString()
+		}
+		s += fmt.Sprintf(attributeIndent+"# %s end\n", p.name)
+		return s
+	}
+	return fmt.Sprintf(attributeIndent+"%q: attr.%s(),\n", p.name, p.starlarkAttrType)
+}
+
+func extractPropertyDescriptionsFromStruct(structType reflect.Type) []property {
+	properties := make([]property, 0)
+	for i := 0; i < structType.NumField(); i++ {
+		field := structType.Field(i)
+		if shouldSkipStructField(field) {
+			continue
+		}
+
+		properties = append(properties, extractPropertyDescriptions(field.Name, field.Type)...)
+	}
+	return properties
+}
+
+func extractPropertyDescriptions(name string, t reflect.Type) []property {
+	name = proptools.PropertyNameForField(name)
+
+	// TODO: handle android:paths tags, they should be changed to label types
+
+	starlarkAttrType := fmt.Sprintf("%s", t.Name())
+	props := make([]property, 0)
+
+	switch t.Kind() {
+	case reflect.Bool, reflect.String:
+		// do nothing
+	case reflect.Uint, reflect.Int, reflect.Int64:
+		starlarkAttrType = "int"
+	case reflect.Slice:
+		if t.Elem().Kind() != reflect.String {
+			// TODO: handle lists of non-strings (currently only list of Dist)
+			return []property{}
+		}
+		starlarkAttrType = "string_list"
+	case reflect.Struct:
+		props = extractPropertyDescriptionsFromStruct(t)
+	case reflect.Ptr:
+		return extractPropertyDescriptions(name, t.Elem())
+	case reflect.Interface:
+		// Interfaces are used for for arch, multilib and target properties, which are handled at runtime.
+		// These will need to be handled in a bazel-specific version of the arch mutator.
+		return []property{}
+	}
+
+	prop := property{
+		name:             name,
+		starlarkAttrType: starlarkAttrType,
+		properties:       props,
+	}
+
+	return []property{prop}
+}
+
+func getPropertyDescriptions(props []interface{}) []property {
+	// there may be duplicate properties, e.g. from defaults libraries
+	propertiesByName := make(map[string]property)
+	for _, p := range props {
+		for _, prop := range extractPropertyDescriptionsFromStruct(reflect.ValueOf(p).Elem().Type()) {
+			propertiesByName[prop.name] = prop
+		}
+	}
+
+	properties := make([]property, 0, len(propertiesByName))
+	for _, key := range android.SortedStringKeys(propertiesByName) {
+		properties = append(properties, propertiesByName[key])
+	}
+
+	return properties
+}
+
+func getAttributes(factory android.ModuleFactory) string {
+	attrs := ""
+	for _, p := range getPropertyDescriptions(factory().GetProperties()) {
+		attrs += p.attributeString()
+	}
+	return attrs
+}
diff --git a/bp2build/bzl_conversion_test.go b/bp2build/bzl_conversion_test.go
new file mode 100644
index 000000000..8bea3f6cf
--- /dev/null
+++ b/bp2build/bzl_conversion_test.go
@@ -0,0 +1,208 @@
+// Copyright 2020 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"
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+)
+
+var buildDir string
+
+func setUp() {
+	var err error
+	buildDir, err = ioutil.TempDir("", "bazel_queryview_test")
+	if err != nil {
+		panic(err)
+	}
+}
+
+func tearDown() {
+	os.RemoveAll(buildDir)
+}
+
+func TestMain(m *testing.M) {
+	run := func() int {
+		setUp()
+		defer tearDown()
+
+		return m.Run()
+	}
+
+	os.Exit(run())
+}
+
+func TestGenerateModuleRuleShims(t *testing.T) {
+	moduleTypeFactories := map[string]android.ModuleFactory{
+		"custom":          customModuleFactoryBase,
+		"custom_test":     customTestModuleFactoryBase,
+		"custom_defaults": customDefaultsModuleFactoryBasic,
+	}
+	ruleShims := CreateRuleShims(moduleTypeFactories)
+
+	if len(ruleShims) != 1 {
+		t.Errorf("Expected to generate 1 rule shim, but got %d", len(ruleShims))
+	}
+
+	ruleShim := ruleShims["bp2build"]
+	expectedRules := []string{
+		"custom",
+		"custom_defaults",
+		"custom_test_",
+	}
+
+	if len(ruleShim.rules) != len(expectedRules) {
+		t.Errorf("Expected %d rules, but got %d", len(expectedRules), len(ruleShim.rules))
+	}
+
+	for i, rule := range ruleShim.rules {
+		if rule != expectedRules[i] {
+			t.Errorf("Expected rule shim to contain %s, but got %s", expectedRules[i], rule)
+		}
+	}
+	expectedBzl := `load("//build/bazel/queryview_rules:providers.bzl", "SoongModuleInfo")
+
+def _custom_impl(ctx):
+    return [SoongModuleInfo()]
+
+custom = rule(
+    implementation = _custom_impl,
+    attrs = {
+        "module_name": attr.string(mandatory = True),
+        "module_variant": attr.string(),
+        "module_deps": attr.label_list(providers = [SoongModuleInfo]),
+        "bool_prop": attr.bool(),
+        "bool_ptr_prop": attr.bool(),
+        "int64_ptr_prop": attr.int(),
+        # nested_props start
+#         "nested_prop": attr.string(),
+        # nested_props end
+        # nested_props_ptr start
+#         "nested_prop": attr.string(),
+        # nested_props_ptr end
+        "string_list_prop": attr.string_list(),
+        "string_prop": attr.string(),
+        "string_ptr_prop": attr.string(),
+    },
+)
+
+def _custom_defaults_impl(ctx):
+    return [SoongModuleInfo()]
+
+custom_defaults = rule(
+    implementation = _custom_defaults_impl,
+    attrs = {
+        "module_name": attr.string(mandatory = True),
+        "module_variant": attr.string(),
+        "module_deps": attr.label_list(providers = [SoongModuleInfo]),
+        "bool_prop": attr.bool(),
+        "bool_ptr_prop": attr.bool(),
+        "int64_ptr_prop": attr.int(),
+        # nested_props start
+#         "nested_prop": attr.string(),
+        # nested_props end
+        # nested_props_ptr start
+#         "nested_prop": attr.string(),
+        # nested_props_ptr end
+        "string_list_prop": attr.string_list(),
+        "string_prop": attr.string(),
+        "string_ptr_prop": attr.string(),
+    },
+)
+
+def _custom_test__impl(ctx):
+    return [SoongModuleInfo()]
+
+custom_test_ = rule(
+    implementation = _custom_test__impl,
+    attrs = {
+        "module_name": attr.string(mandatory = True),
+        "module_variant": attr.string(),
+        "module_deps": attr.label_list(providers = [SoongModuleInfo]),
+        "bool_prop": attr.bool(),
+        "bool_ptr_prop": attr.bool(),
+        "int64_ptr_prop": attr.int(),
+        # nested_props start
+#         "nested_prop": attr.string(),
+        # nested_props end
+        # nested_props_ptr start
+#         "nested_prop": attr.string(),
+        # nested_props_ptr end
+        "string_list_prop": attr.string_list(),
+        "string_prop": attr.string(),
+        "string_ptr_prop": attr.string(),
+        # test_prop start
+#         "test_string_prop": attr.string(),
+        # test_prop end
+    },
+)
+`
+
+	if ruleShim.content != expectedBzl {
+		t.Errorf(
+			"Expected the generated rule shim bzl to be:\n%s\nbut got:\n%s",
+			expectedBzl,
+			ruleShim.content)
+	}
+}
+
+func TestGenerateSoongModuleBzl(t *testing.T) {
+	ruleShims := map[string]RuleShim{
+		"file1": RuleShim{
+			rules:   []string{"a", "b"},
+			content: "irrelevant",
+		},
+		"file2": RuleShim{
+			rules:   []string{"c", "d"},
+			content: "irrelevant",
+		},
+	}
+	files := CreateBazelFiles(ruleShims, make(map[string][]BazelTarget))
+
+	var actualSoongModuleBzl BazelFile
+	for _, f := range files {
+		if f.Basename == "soong_module.bzl" {
+			actualSoongModuleBzl = f
+		}
+	}
+
+	expectedLoad := `load("//build/bazel/queryview_rules:file1.bzl", "a", "b")
+load("//build/bazel/queryview_rules:file2.bzl", "c", "d")
+`
+	expectedRuleMap := `soong_module_rule_map = {
+    "a": a,
+    "b": b,
+    "c": c,
+    "d": d,
+}`
+	if !strings.Contains(actualSoongModuleBzl.Contents, expectedLoad) {
+		t.Errorf(
+			"Generated soong_module.bzl:\n\n%s\n\n"+
+				"Could not find the load statement in the generated soong_module.bzl:\n%s",
+			actualSoongModuleBzl.Contents,
+			expectedLoad)
+	}
+
+	if !strings.Contains(actualSoongModuleBzl.Contents, expectedRuleMap) {
+		t.Errorf(
+			"Generated soong_module.bzl:\n\n%s\n\n"+
+				"Could not find the module -> rule map in the generated soong_module.bzl:\n%s",
+			actualSoongModuleBzl.Contents,
+			expectedRuleMap)
+	}
+}
diff --git a/bp2build/conversion.go b/bp2build/conversion.go
new file mode 100644
index 000000000..cdfb38b14
--- /dev/null
+++ b/bp2build/conversion.go
@@ -0,0 +1,118 @@
+package bp2build
+
+import (
+	"android/soong/android"
+	"reflect"
+	"sort"
+	"strings"
+
+	"github.com/google/blueprint/proptools"
+)
+
+type BazelFile struct {
+	Dir      string
+	Basename string
+	Contents string
+}
+
+func CreateBazelFiles(
+	ruleShims map[string]RuleShim,
+	buildToTargets map[string][]BazelTarget) []BazelFile {
+	files := make([]BazelFile, 0, len(ruleShims)+len(buildToTargets)+numAdditionalFiles)
+
+	// Write top level files: WORKSPACE and BUILD. These files are empty.
+	files = append(files, newFile("", "WORKSPACE", ""))
+	// Used to denote that the top level directory is a package.
+	files = append(files, newFile("", "BUILD", ""))
+
+	files = append(files, newFile(bazelRulesSubDir, "BUILD", ""))
+	files = append(files, newFile(bazelRulesSubDir, "providers.bzl", providersBzl))
+
+	for bzlFileName, ruleShim := range ruleShims {
+		files = append(files, newFile(bazelRulesSubDir, bzlFileName+".bzl", ruleShim.content))
+	}
+	files = append(files, newFile(bazelRulesSubDir, "soong_module.bzl", generateSoongModuleBzl(ruleShims)))
+
+	files = append(files, createBuildFiles(buildToTargets)...)
+
+	return files
+}
+
+func createBuildFiles(buildToTargets map[string][]BazelTarget) []BazelFile {
+	files := make([]BazelFile, 0, len(buildToTargets))
+	for _, dir := range android.SortedStringKeys(buildToTargets) {
+		content := soongModuleLoad
+		targets := buildToTargets[dir]
+		sort.Slice(targets, func(i, j int) bool { return targets[i].name < targets[j].name })
+		for _, t := range targets {
+			content += "\n\n"
+			content += t.content
+		}
+		files = append(files, newFile(dir, "BUILD.bazel", content))
+	}
+	return files
+}
+
+func newFile(dir, basename, content string) BazelFile {
+	return BazelFile{
+		Dir:      dir,
+		Basename: basename,
+		Contents: content,
+	}
+}
+
+const (
+	bazelRulesSubDir = "build/bazel/queryview_rules"
+
+	// additional files:
+	//  * workspace file
+	//  * base BUILD file
+	//  * rules BUILD file
+	//  * rules providers.bzl file
+	//  * rules soong_module.bzl file
+	numAdditionalFiles = 5
+)
+
+var (
+	// Certain module property names are blocklisted/ignored here, for the reasons commented.
+	ignoredPropNames = map[string]bool{
+		"name":       true, // redundant, since this is explicitly generated for every target
+		"from":       true, // reserved keyword
+		"in":         true, // reserved keyword
+		"arch":       true, // interface prop type is not supported yet.
+		"multilib":   true, // interface prop type is not supported yet.
+		"target":     true, // interface prop type is not supported yet.
+		"visibility": true, // Bazel has native visibility semantics. Handle later.
+		"features":   true, // There is already a built-in attribute 'features' which cannot be overridden.
+	}
+)
+
+func shouldGenerateAttribute(prop string) bool {
+	return !ignoredPropNames[prop]
+}
+
+func shouldSkipStructField(field reflect.StructField) bool {
+	if field.PkgPath != "" {
+		// Skip unexported fields. Some properties are
+		// 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
+	// but cannot be set in a .bp file
+	if proptools.HasTag(field, "blueprint", "mutated") {
+		return true
+	}
+	return false
+}
+
+// FIXME(b/168089390): In Bazel, rules ending with "_test" needs to be marked as
+// testonly = True, forcing other rules that depend on _test rules to also be
+// marked as testonly = True. This semantic constraint is not present in Soong.
+// To work around, rename "*_test" rules to "*_test_".
+func canonicalizeModuleType(moduleName string) string {
+	if strings.HasSuffix(moduleName, "_test") {
+		return moduleName + "_"
+	}
+
+	return moduleName
+}
diff --git a/bp2build/conversion_test.go b/bp2build/conversion_test.go
new file mode 100644
index 000000000..a38fa6a55
--- /dev/null
+++ b/bp2build/conversion_test.go
@@ -0,0 +1,73 @@
+// Copyright 2020 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 (
+	"sort"
+	"testing"
+)
+
+func TestCreateBazelFiles_AddsTopLevelFiles(t *testing.T) {
+	files := CreateBazelFiles(map[string]RuleShim{}, map[string][]BazelTarget{})
+	expectedFilePaths := []struct {
+		dir      string
+		basename string
+	}{
+		{
+			dir:      "",
+			basename: "BUILD",
+		},
+		{
+			dir:      "",
+			basename: "WORKSPACE",
+		},
+		{
+			dir:      bazelRulesSubDir,
+			basename: "BUILD",
+		},
+		{
+			dir:      bazelRulesSubDir,
+			basename: "providers.bzl",
+		},
+		{
+			dir:      bazelRulesSubDir,
+			basename: "soong_module.bzl",
+		},
+	}
+
+	if g, w := len(files), len(expectedFilePaths); g != w {
+		t.Errorf("Expected %d files, got %d", w, g)
+	}
+
+	sort.Slice(files, func(i, j int) bool {
+		if dir1, dir2 := files[i].Dir, files[j].Dir; dir1 == dir2 {
+			return files[i].Basename < files[j].Basename
+		} else {
+			return dir1 < dir2
+		}
+	})
+
+	for i := range files {
+		if g, w := files[i], expectedFilePaths[i]; g.Dir != w.dir || g.Basename != w.basename {
+			t.Errorf("Did not find expected file %s/%s", g.Dir, g.Basename)
+		} else if g.Basename == "BUILD" || g.Basename == "WORKSPACE" {
+			if g.Contents != "" {
+				t.Errorf("Expected %s to have no content.", g)
+			}
+		} else if g.Contents == "" {
+			t.Errorf("Contents of %s unexpected empty.", g)
+		}
+	}
+}
diff --git a/bp2build/testing.go b/bp2build/testing.go
new file mode 100644
index 000000000..160412de8
--- /dev/null
+++ b/bp2build/testing.go
@@ -0,0 +1,136 @@
+package bp2build
+
+import (
+	"android/soong/android"
+
+	"github.com/google/blueprint"
+)
+
+type nestedProps struct {
+	Nested_prop string
+}
+
+type customProps struct {
+	Bool_prop     bool
+	Bool_ptr_prop *bool
+	// Ensure that properties tagged `blueprint:mutated` are omitted
+	Int_prop         int `blueprint:"mutated"`
+	Int64_ptr_prop   *int64
+	String_prop      string
+	String_ptr_prop  *string
+	String_list_prop []string
+
+	Nested_props     nestedProps
+	Nested_props_ptr *nestedProps
+}
+
+type customModule struct {
+	android.ModuleBase
+
+	props customProps
+}
+
+// OutputFiles is needed because some instances of this module use dist with a
+// tag property which requires the module implements OutputFileProducer.
+func (m *customModule) OutputFiles(tag string) (android.Paths, error) {
+	return android.PathsForTesting("path" + tag), nil
+}
+
+func (m *customModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	// nothing for now.
+}
+
+func customModuleFactoryBase() android.Module {
+	module := &customModule{}
+	module.AddProperties(&module.props)
+	return module
+}
+
+func customModuleFactory() android.Module {
+	m := customModuleFactoryBase()
+	android.InitAndroidModule(m)
+	return m
+}
+
+type testProps struct {
+	Test_prop struct {
+		Test_string_prop string
+	}
+}
+
+type customTestModule struct {
+	android.ModuleBase
+
+	props      customProps
+	test_props testProps
+}
+
+func (m *customTestModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	// nothing for now.
+}
+
+func customTestModuleFactoryBase() android.Module {
+	m := &customTestModule{}
+	m.AddProperties(&m.props)
+	m.AddProperties(&m.test_props)
+	return m
+}
+
+func customTestModuleFactory() android.Module {
+	m := customTestModuleFactoryBase()
+	android.InitAndroidModule(m)
+	return m
+}
+
+type customDefaultsModule struct {
+	android.ModuleBase
+	android.DefaultsModuleBase
+}
+
+func customDefaultsModuleFactoryBase() android.DefaultsModule {
+	module := &customDefaultsModule{}
+	module.AddProperties(&customProps{})
+	return module
+}
+
+func customDefaultsModuleFactoryBasic() android.Module {
+	return customDefaultsModuleFactoryBase()
+}
+
+func customDefaultsModuleFactory() android.Module {
+	m := customDefaultsModuleFactoryBase()
+	android.InitDefaultsModule(m)
+	return m
+}
+
+type bp2buildBlueprintWrapContext struct {
+	bpCtx *blueprint.Context
+}
+
+func (ctx *bp2buildBlueprintWrapContext) ModuleName(module blueprint.Module) string {
+	return ctx.bpCtx.ModuleName(module)
+}
+
+func (ctx *bp2buildBlueprintWrapContext) ModuleDir(module blueprint.Module) string {
+	return ctx.bpCtx.ModuleDir(module)
+}
+
+func (ctx *bp2buildBlueprintWrapContext) ModuleSubDir(module blueprint.Module) string {
+	return ctx.bpCtx.ModuleSubDir(module)
+}
+
+func (ctx *bp2buildBlueprintWrapContext) ModuleType(module blueprint.Module) string {
+	return ctx.bpCtx.ModuleType(module)
+}
+
+func (ctx *bp2buildBlueprintWrapContext) VisitAllModulesBlueprint(visit func(blueprint.Module)) {
+	ctx.bpCtx.VisitAllModules(visit)
+}
+
+func (ctx *bp2buildBlueprintWrapContext) VisitDirectDeps(module android.Module, visit func(android.Module)) {
+	ctx.bpCtx.VisitDirectDeps(module, func(m blueprint.Module) {
+		if aModule, ok := m.(android.Module); ok {
+			visit(aModule)
+		}
+	})
+}