Surface module properties as Bazel BUILD target attributes in the Bazel overlay
This patchset changes bazel_overlay to generate soong_module as a macro,
instead of a rule, and generate module properties in the BUILD files as
kwargs to the soong_module macro.
Here's a sample of the new BUILD files with module properties:
bionic/libdl/BUILD.bazel:
https://paste.googleplex.com/6484466996346880?raw
art/build/apex/BUILD.bazel:
https://paste.googleplex.com/5461276001042432?raw
bionic/apex/BUILD.bazel:
https://paste.googleplex.com/4932795173437440?raw
soong_module is now a macro that conditionally expands to underlying
soong_<module type> rules with statically defined attributes. In this
CL, we are starting with a hardcoded filegroup rule definition to
demonstrate the conditional rule loading within the soong_module macro.
If the module_type matches an existing Bazel rule, soong_module forwards
the entire **kwargs into the rule, which Bazel typechecks.
Non-filegroup module types will be expanded into generic_soong_module,
but with the kwargs dropped.
This approach allows us to:
1) Programmtically generate soong_<module type> rules for all module
types available in Soong, together with the statically defined attribute
types in `attrs`.
2) Incrementally migrate and test individual module types from
generic_soong_module to their module rule shims.
3) Swap out the module rule shims to the actual Bazel rules (e.g
cc_library, java_library) and perform attribute manipulation in Starlark
itself.
Example of querying against the 'srcs' attribute in soong_filegroup:
```
$ bazel cquery 'kind(soong_filegroup, //...)' | wc -l
590
$ bazel cquery --output=build 'attr(srcs, "linker.cpp",
kind(soong_filegroup, //bionic/...))'
INFO: Analyzed 3907 targets (0 packages loaded, 0 targets configured).
INFO: Found 3907 targets...
/usr/local/google/home/jingwen/aosp/out/soong/bazel_overlay/bionic/linker/BUILD.bazel:4144:13
soong_filegroup(
name = "linker_sources",
generator_name = "linker_sources",
generator_function = "soong_module",
generator_location = "bionic/linker/BUILD.bazel:4144:13",
srcs = ["dlfcn.cpp", "linker.cpp", "linker_block_allocator.cpp",
"linker_dlwarning.cpp", "linker_cfi.cpp", "linker_config.cpp",
"linker_debug.cpp", "linker_gdb_support.cpp", "linker_globals.cpp",
"linker_libc_support.c", "linker_libcxx_support.cpp",
"linker_namespaces.cpp", "linker_logger.cpp",
"linker_mapped_file_fragment.cpp", "linker_phdr.cpp",
"linker_relocate.cpp", "linker_sdk_versions.cpp", "linker_soinfo.cpp",
"linker_tls.cpp", "linker_utils.cpp", "rt.cpp"],
deps = [],
)
/usr/local/google/home/jingwen/aosp/out/soong/bazel_overlay/soong_module.bzl:32:23
in <toplevel>
```
This CL is known to be lacking the following features, and will be looked at in follow up CLs:
1) Pretty printing reflect.Interface properties, like arch, multilib and
dists.
2) Generating module Bazel rule shims for all module types, instead of
hardcoding them like `soong_filegroup`.
Bug: 162720644
Test: bazel_overlay_test.go (soong build test)
Test: m bazel_overlay && cd out/soong/bazel_overlay && bazel cquery //...
Signed-off-by: Jingwen Chen <jingwen@google.com>
Change-Id: Ic1e448887eb540ed15a55bc4090cf75a4d832d41
diff --git a/cmd/soong_build/Android.bp b/cmd/soong_build/Android.bp
index 7b8352b..4ebbe68 100644
--- a/cmd/soong_build/Android.bp
+++ b/cmd/soong_build/Android.bp
@@ -28,5 +28,8 @@
"writedocs.go",
"bazel_overlay.go",
],
+ testSrcs: [
+ "bazel_overlay_test.go",
+ ],
primaryBuilder: true,
}
diff --git a/cmd/soong_build/bazel_overlay.go b/cmd/soong_build/bazel_overlay.go
index e37c163..e1d3d41 100644
--- a/cmd/soong_build/bazel_overlay.go
+++ b/cmd/soong_build/bazel_overlay.go
@@ -20,14 +20,17 @@
"io/ioutil"
"os"
"path/filepath"
+ "reflect"
"strings"
"github.com/google/blueprint"
+ "github.com/google/blueprint/proptools"
)
const (
soongModuleLoad = `package(default_visibility = ["//visibility:public"])
load("//:soong_module.bzl", "soong_module")
+
`
// A BUILD file target snippet representing a Soong module
@@ -36,15 +39,11 @@
module_name = "%s",
module_type = "%s",
module_variant = "%s",
- deps = [
- %s
- ],
-)
-`
+ deps = %s,
+%s)`
// The soong_module rule implementation in a .bzl file
- soongModuleBzl = `
-SoongModuleInfo = provider(
+ soongModuleBzl = `SoongModuleInfo = provider(
fields = {
"name": "Name of module",
"type": "Type of module",
@@ -52,7 +51,17 @@
},
)
-def _soong_module_impl(ctx):
+def _merge_dicts(*dicts):
+ """Adds a list of dictionaries into a single dictionary."""
+
+ # If keys are repeated in multiple dictionaries, the latter one "wins".
+ result = {}
+ for d in dicts:
+ result.update(d)
+
+ return result
+
+def _generic_soong_module_impl(ctx):
return [
SoongModuleInfo(
name = ctx.attr.module_name,
@@ -61,21 +70,66 @@
),
]
-soong_module = rule(
- implementation = _soong_module_impl,
- attrs = {
- "module_name": attr.string(mandatory = True),
- "module_type": attr.string(mandatory = True),
- "module_variant": attr.string(),
- "deps": attr.label_list(providers = [SoongModuleInfo]),
- },
+_COMMON_ATTRS = {
+ "module_name": attr.string(mandatory = True),
+ "module_type": attr.string(mandatory = True),
+ "module_variant": attr.string(),
+ "deps": attr.label_list(providers = [SoongModuleInfo]),
+}
+
+
+generic_soong_module = rule(
+ implementation = _generic_soong_module_impl,
+ attrs = _COMMON_ATTRS,
)
+
+# TODO(jingwen): auto generate Soong module shims
+def _soong_filegroup_impl(ctx):
+ return [SoongModuleInfo(),]
+
+soong_filegroup = rule(
+ implementation = _soong_filegroup_impl,
+ # Matches https://cs.android.com/android/platform/superproject/+/master:build/soong/android/filegroup.go;l=25-40;drc=6a6478d49e78703ba22a432c41d819c8df79ef6c
+ attrs = _merge_dicts(_COMMON_ATTRS, {
+ "srcs": attr.string_list(doc = "srcs lists files that will be included in this filegroup"),
+ "exclude_srcs": attr.string_list(),
+ "path": attr.string(doc = "The base path to the files. May be used by other modules to determine which portion of the path to use. For example, when a filegroup is used as data in a cc_test rule, the base path is stripped off the path and the remaining path is used as the installation directory."),
+ "export_to_make_var": attr.string(doc = "Create a make variable with the specified name that contains the list of files in the filegroup, relative to the root of the source tree."),
+ })
+)
+
+soong_module_rule_map = {
+ "filegroup": soong_filegroup,
+}
+
+# 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", ""),
+ deps = kwargs.pop("deps", []),
+ )
+ else:
+ soong_module_rule(
+ name = name,
+ module_type = module_type,
+ **kwargs,
+ )
`
)
func targetNameWithVariant(c *blueprint.Context, 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)
@@ -95,6 +149,153 @@
return filepath.Dir(c.BlueprintFile(logicModule))
}
+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)
+}
+
+// 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 += "\"" + k + "\": "
+ ret += structProps[k]
+ ret += ",\n"
+ }
+ 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
+}
+
+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 field.PkgPath != "" {
+ // Skip unexported fields. Some properties are
+ // internal to Soong only, and these fields do not have PkgPath.
+ continue
+ }
+ if proptools.HasTag(field, "blueprint", "mutated") {
+ 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 isStructPtr(t reflect.Type) bool {
+ return t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct
+}
+
+// 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 createBazelOverlay(ctx *android.Context, bazelOverlayDir string) error {
blueprintCtx := ctx.Context
blueprintCtx.VisitAllModules(func(module blueprint.Module) {
@@ -103,27 +304,7 @@
panic(err)
}
- // 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{}
- blueprintCtx.VisitDirectDeps(module, func(depModule blueprint.Module) {
- depLabels[qualifiedTargetLabel(blueprintCtx, depModule)] = true
- })
-
- var depLabelList string
- for depLabel, _ := range depLabels {
- depLabelList += "\"" + depLabel + "\",\n "
- }
- buildFile.Write([]byte(
- fmt.Sprintf(
- soongModuleTarget,
- targetNameWithVariant(blueprintCtx, module),
- blueprintCtx.ModuleName(module),
- blueprintCtx.ModuleType(module),
- // misleading name, this actually returns the variant.
- blueprintCtx.ModuleSubDir(module),
- depLabelList)))
+ buildFile.Write([]byte(generateSoongModuleTarget(blueprintCtx, module) + "\n\n"))
buildFile.Close()
})
@@ -138,6 +319,70 @@
return writeReadOnlyFile(bazelOverlayDir, "soong_module.bzl", soongModuleBzl)
}
+var ignoredProps map[string]bool = 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.
+}
+
+func shouldGenerateAttribute(prop string) bool {
+ return !ignoredProps[prop]
+}
+
+// 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
+}
+
+// Convert a module and its deps and props into a Bazel macro/rule
+// representation in the BUILD file.
+func generateSoongModuleTarget(
+ blueprintCtx *blueprint.Context,
+ module blueprint.Module) string {
+
+ var props map[string]string
+ if aModule, ok := module.(android.Module); ok {
+ props = extractModuleProperties(aModule)
+ }
+ attributes := propsToAttributes(props)
+
+ // 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{}
+ blueprintCtx.VisitDirectDeps(module, func(depModule blueprint.Module) {
+ depLabels[qualifiedTargetLabel(blueprintCtx, depModule)] = true
+ })
+
+ depLabelList := "[\n"
+ for depLabel, _ := range depLabels {
+ depLabelList += " \""
+ depLabelList += depLabel
+ depLabelList += "\",\n"
+ }
+ depLabelList += " ]"
+
+ return fmt.Sprintf(
+ soongModuleTarget,
+ targetNameWithVariant(blueprintCtx, module),
+ blueprintCtx.ModuleName(module),
+ blueprintCtx.ModuleType(module),
+ blueprintCtx.ModuleSubDir(module),
+ depLabelList,
+ attributes)
+}
+
func buildFileForModule(ctx *blueprint.Context, module blueprint.Module) (*os.File, error) {
// Create nested directories for the BUILD file
dirPath := filepath.Join(bazelOverlayDir, packagePath(ctx, module))
@@ -171,3 +416,34 @@
// 0444 is read-only
return ioutil.WriteFile(workspaceFile, []byte(content), 0444)
}
+
+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
+ }
+}
diff --git a/cmd/soong_build/bazel_overlay_test.go b/cmd/soong_build/bazel_overlay_test.go
new file mode 100644
index 0000000..67599c0
--- /dev/null
+++ b/cmd/soong_build/bazel_overlay_test.go
@@ -0,0 +1,255 @@
+// 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 main
+
+import (
+ "android/soong/android"
+ "io/ioutil"
+ "os"
+ "testing"
+)
+
+var buildDir string
+
+func setUp() {
+ var err error
+ buildDir, err = ioutil.TempDir("", "bazel_overlay_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())
+}
+
+type customModule struct {
+ android.ModuleBase
+}
+
+func (m *customModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+ // nothing for now.
+}
+
+func customModuleFactory() android.Module {
+ module := &customModule{}
+ android.InitAndroidModule(module)
+ return module
+}
+
+func TestGenerateBazelOverlayFromBlueprint(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 = "",
+ deps = [
+ ],
+)`,
+ },
+ {
+ bp: `custom {
+ name: "foo",
+ ramdisk: true,
+}
+ `,
+ expectedBazelTarget: `soong_module(
+ name = "foo",
+ module_name = "foo",
+ module_type = "custom",
+ module_variant = "",
+ 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 = "",
+ 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 = "",
+ deps = [
+ ],
+ required = [
+ "bar",
+ ],
+)`,
+ },
+ {
+ bp: `custom {
+ name: "foo",
+ target_required: ["qux", "bazqux"],
+}
+ `,
+ expectedBazelTarget: `soong_module(
+ name = "foo",
+ module_name = "foo",
+ module_type = "custom",
+ module_variant = "",
+ 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 = "",
+ 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 = "",
+ deps = [
+ ],
+ dists = [
+ {
+ "tag": ".tag",
+ "targets": [
+ "my_goal",
+ ],
+ },
+ ],
+ owner = "custom_owner",
+ ramdisk = True,
+ required = [
+ "bar",
+ ],
+ target_required = [
+ "qux",
+ "bazqux",
+ ],
+)`,
+ },
+ }
+
+ for _, testCase := range testCases {
+ config := android.TestConfig(buildDir, nil, testCase.bp, nil)
+ ctx := android.NewTestContext()
+ ctx.RegisterModuleType("custom", customModuleFactory)
+ ctx.Register(config)
+
+ _, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+ android.FailIfErrored(t, errs)
+ _, errs = ctx.PrepareBuildActions(config)
+ android.FailIfErrored(t, errs)
+
+ module := ctx.ModuleForTests("foo", "").Module().(*customModule)
+ blueprintCtx := ctx.Context.Context
+
+ actualBazelTarget := generateSoongModuleTarget(blueprintCtx, module)
+ if actualBazelTarget != testCase.expectedBazelTarget {
+ t.Errorf(
+ "Expected generated Bazel target to be '%s', got '%s'",
+ testCase.expectedBazelTarget,
+ actualBazelTarget,
+ )
+ }
+ }
+}
