bp2build: add configurable attribute (select) support.
This CL adds a basic framework to support configurable string_list
attributes, selecting on the Arch variant (x86, x86_64, arm, arm64).
It offers fine-grained controls to map individual configurable
properties (arch_variant) to configurable Bazel attributes, starting
with the string_list type for the copts property for cc_object.
This design is primarily motivated to have minimal boilerplate in
bp2build mutators, allowing anyone to opt-in configurable attributes,
and modify intermediate states before passing them on into the
CreateBazelTargetModule instantiator.
Fixes: 178130668
Test: go tests
Test: build/bazel/scripts/milestone-2/demo.sh
Change-Id: Id6f04d7c560312a93e193d7ca4e1b7ceb6062260
diff --git a/android/arch.go b/android/arch.go
index f719ddc..20b4ab0 100644
--- a/android/arch.go
+++ b/android/arch.go
@@ -1615,3 +1615,97 @@
return buildTargets, nil
}
+
+// GetArchProperties returns a map of architectures to the values of the
+// properties of the 'dst' struct that are specific to that architecture.
+//
+// For example, passing a struct { Foo bool, Bar string } will return an
+// interface{} that can be type asserted back into the same struct, containing
+// the arch specific property value specified by the module if defined.
+func (m *ModuleBase) GetArchProperties(dst interface{}) map[ArchType]interface{} {
+ // Return value of the arch types to the prop values for that arch.
+ archToProp := map[ArchType]interface{}{}
+
+ // Nothing to do for non-arch-specific modules.
+ if !m.ArchSpecific() {
+ return archToProp
+ }
+
+ // archProperties has the type of [][]interface{}. Looks complicated, so let's
+ // explain this step by step.
+ //
+ // Loop over the outer index, which determines the property struct that
+ // contains a matching set of properties in dst that we're interested in.
+ // For example, BaseCompilerProperties or BaseLinkerProperties.
+ for i := range m.archProperties {
+ if m.archProperties[i] == nil {
+ // Skip over nil arch props
+ continue
+ }
+
+ // Non-nil arch prop, let's see if the props match up.
+ for _, arch := range ArchTypeList() {
+ // e.g X86, Arm
+ field := arch.Field
+
+ // If it's not nil, loop over the inner index, which determines the arch variant
+ // of the prop type. In an Android.bp file, this is like looping over:
+ //
+ // arch: { arm: { key: value, ... }, x86: { key: value, ... } }
+ for _, archProperties := range m.archProperties[i] {
+ archPropValues := reflect.ValueOf(archProperties).Elem()
+
+ // This is the archPropRoot struct. Traverse into the Arch nested struct.
+ src := archPropValues.FieldByName("Arch").Elem()
+
+ // Step into non-nil pointers to structs in the src value.
+ if src.Kind() == reflect.Ptr {
+ if src.IsNil() {
+ // Ignore nil pointers.
+ continue
+ }
+ src = src.Elem()
+ }
+
+ // Find the requested field (e.g. x86, x86_64) in the src struct.
+ src = src.FieldByName(field)
+ if !src.IsValid() {
+ continue
+ }
+
+ // We only care about structs. These are not the droids you are looking for.
+ if src.Kind() != reflect.Struct {
+ continue
+ }
+
+ // If the value of the field is a struct then step into the
+ // BlueprintEmbed field. The special "BlueprintEmbed" name is
+ // used by createArchPropTypeDesc to embed the arch properties
+ // in the parent struct, so the src arch prop should be in this
+ // field.
+ //
+ // See createArchPropTypeDesc for more details on how Arch-specific
+ // module properties are processed from the nested props and written
+ // into the module's archProperties.
+ src = src.FieldByName("BlueprintEmbed")
+
+ // Clone the destination prop, since we want a unique prop struct per arch.
+ dstClone := reflect.New(reflect.ValueOf(dst).Elem().Type()).Interface()
+
+ // Copy the located property struct into the cloned destination property struct.
+ err := proptools.ExtendMatchingProperties([]interface{}{dstClone}, src.Interface(), nil, proptools.OrderReplace)
+ if err != nil {
+ // This is fine, it just means the src struct doesn't match.
+ continue
+ }
+
+ // Found the prop for the arch, you have.
+ archToProp[arch] = dstClone
+
+ // Go to the next prop.
+ break
+ }
+ }
+ }
+ return archToProp
+}
diff --git a/android/module.go b/android/module.go
index 5342246..1936d3c 100644
--- a/android/module.go
+++ b/android/module.go
@@ -1123,8 +1123,15 @@
variableProperties interface{}
hostAndDeviceProperties hostAndDeviceProperties
generalProperties []interface{}
- archProperties [][]interface{}
- customizableProperties []interface{}
+
+ // Arch specific versions of structs in generalProperties. The outer index
+ // has the same order as generalProperties as initialized in
+ // InitAndroidArchModule, and the inner index chooses the props specific to
+ // the architecture. The interface{} value is an archPropRoot that is
+ // filled with arch specific values by the arch mutator.
+ archProperties [][]interface{}
+
+ customizableProperties []interface{}
// Properties specific to the Blueprint to BUILD migration.
bazelTargetModuleProperties bazel.BazelTargetModuleProperties
diff --git a/bazel/properties.go b/bazel/properties.go
index a4df4bc..a5ffa55 100644
--- a/bazel/properties.go
+++ b/bazel/properties.go
@@ -14,6 +14,8 @@
package bazel
+import "fmt"
+
type bazelModuleProperties struct {
// The label of the Bazel target replacing this Soong module.
Label string
@@ -63,3 +65,72 @@
ll.Excludes = append(other.Excludes, other.Excludes...)
}
}
+
+// StringListAttribute corresponds to the string_list Bazel attribute type with
+// support for additional metadata, like configurations.
+type StringListAttribute struct {
+ // The base value of the string list attribute.
+ Value []string
+
+ // Optional additive set of list values to the base value.
+ ArchValues stringListArchValues
+}
+
+// Arch-specific string_list typed Bazel attribute values. This should correspond
+// to the types of architectures supported for compilation in arch.go.
+type stringListArchValues struct {
+ X86 []string
+ X86_64 []string
+ Arm []string
+ Arm64 []string
+ Default []string
+ // TODO(b/181299724): this is currently missing the "common" arch, which
+ // doesn't have an equivalent platform() definition yet.
+}
+
+// HasArchSpecificValues returns true if the attribute contains
+// architecture-specific string_list values.
+func (attrs *StringListAttribute) HasArchSpecificValues() bool {
+ for _, arch := range []string{"x86", "x86_64", "arm", "arm64", "default"} {
+ if len(attrs.GetValueForArch(arch)) > 0 {
+ return true
+ }
+ }
+ return false
+}
+
+// GetValueForArch returns the string_list attribute value for an architecture.
+func (attrs *StringListAttribute) GetValueForArch(arch string) []string {
+ switch arch {
+ case "x86":
+ return attrs.ArchValues.X86
+ case "x86_64":
+ return attrs.ArchValues.X86_64
+ case "arm":
+ return attrs.ArchValues.Arm
+ case "arm64":
+ return attrs.ArchValues.Arm64
+ case "default":
+ return attrs.ArchValues.Default
+ default:
+ panic(fmt.Errorf("Unknown arch: %s", arch))
+ }
+}
+
+// SetValueForArch sets the string_list attribute value for an architecture.
+func (attrs *StringListAttribute) SetValueForArch(arch string, value []string) {
+ switch arch {
+ case "x86":
+ attrs.ArchValues.X86 = value
+ case "x86_64":
+ attrs.ArchValues.X86_64 = value
+ case "arm":
+ attrs.ArchValues.Arm = value
+ case "arm64":
+ attrs.ArchValues.Arm64 = value
+ case "default":
+ attrs.ArchValues.Default = value
+ default:
+ panic(fmt.Errorf("Unknown arch: %s", arch))
+ }
+}
diff --git a/bp2build/Android.bp b/bp2build/Android.bp
index 7d748ec..8deb5a2 100644
--- a/bp2build/Android.bp
+++ b/bp2build/Android.bp
@@ -10,6 +10,7 @@
"bp2build.go",
"build_conversion.go",
"bzl_conversion.go",
+ "configurability.go",
"conversion.go",
"metrics.go",
],
diff --git a/bp2build/build_conversion.go b/bp2build/build_conversion.go
index a4c4a0d..7fa4996 100644
--- a/bp2build/build_conversion.go
+++ b/bp2build/build_conversion.go
@@ -354,11 +354,42 @@
ret += makeIndent(indent)
ret += "]"
case reflect.Struct:
+ // Special cases where the bp2build sends additional information to the codegenerator
+ // by wrapping the attributes in a custom struct type.
if labels, ok := propertyValue.Interface().(bazel.LabelList); ok {
// TODO(b/165114590): convert glob syntax
return prettyPrint(reflect.ValueOf(labels.Includes), indent)
} else if label, ok := propertyValue.Interface().(bazel.Label); ok {
return fmt.Sprintf("%q", label.Label), nil
+ } else if stringList, ok := propertyValue.Interface().(bazel.StringListAttribute); ok {
+ // A Bazel string_list attribute that may contain a select statement.
+ ret, err := prettyPrint(reflect.ValueOf(stringList.Value), indent)
+ if err != nil {
+ return ret, err
+ }
+
+ if !stringList.HasArchSpecificValues() {
+ // Select statement not needed.
+ return ret, nil
+ }
+
+ ret += " + " + "select({\n"
+ for _, arch := range android.ArchTypeList() {
+ value := stringList.GetValueForArch(arch.Name)
+ if len(value) > 0 {
+ ret += makeIndent(indent + 1)
+ list, _ := prettyPrint(reflect.ValueOf(value), indent+1)
+ ret += fmt.Sprintf("\"%s\": %s,\n", platformArchMap[arch], list)
+ }
+ }
+
+ ret += makeIndent(indent + 1)
+ list, _ := prettyPrint(reflect.ValueOf(stringList.GetValueForArch("default")), indent+1)
+ ret += fmt.Sprintf("\"%s\": %s,\n", "//conditions:default", list)
+
+ ret += makeIndent(indent)
+ ret += "})"
+ return ret, err
}
ret = "{\n"
diff --git a/bp2build/cc_object_conversion_test.go b/bp2build/cc_object_conversion_test.go
index f655842..1d4e322 100644
--- a/bp2build/cc_object_conversion_test.go
+++ b/bp2build/cc_object_conversion_test.go
@@ -99,15 +99,6 @@
cc_defaults {
name: "foo_defaults",
defaults: ["foo_bar_defaults"],
- // TODO(b/178130668): handle configurable attributes that depend on the platform
- arch: {
- x86: {
- cflags: ["-fPIC"],
- },
- x86_64: {
- cflags: ["-fPIC"],
- },
- },
}
cc_defaults {
@@ -233,3 +224,137 @@
}
}
}
+
+func TestCcObjectConfigurableAttributesBp2Build(t *testing.T) {
+ testCases := []struct {
+ description string
+ moduleTypeUnderTest string
+ moduleTypeUnderTestFactory android.ModuleFactory
+ moduleTypeUnderTestBp2BuildMutator func(android.TopDownMutatorContext)
+ blueprint string
+ expectedBazelTargets []string
+ filesystem map[string]string
+ }{
+ {
+ description: "cc_object setting cflags for one arch",
+ moduleTypeUnderTest: "cc_object",
+ moduleTypeUnderTestFactory: cc.ObjectFactory,
+ moduleTypeUnderTestBp2BuildMutator: cc.ObjectBp2Build,
+ blueprint: `cc_object {
+ name: "foo",
+ arch: {
+ x86: {
+ cflags: ["-fPIC"],
+ },
+ },
+ bazel_module: { bp2build_available: true },
+}
+`,
+ expectedBazelTargets: []string{
+ `cc_object(
+ name = "foo",
+ copts = [
+ "-fno-addrsig",
+ ] + select({
+ "@bazel_tools//platforms:x86_32": [
+ "-fPIC",
+ ],
+ "//conditions:default": [
+ ],
+ }),
+)`,
+ },
+ },
+ {
+ description: "cc_object setting cflags for 4 architectures",
+ moduleTypeUnderTest: "cc_object",
+ moduleTypeUnderTestFactory: cc.ObjectFactory,
+ moduleTypeUnderTestBp2BuildMutator: cc.ObjectBp2Build,
+ blueprint: `cc_object {
+ name: "foo",
+ arch: {
+ x86: {
+ cflags: ["-fPIC"],
+ },
+ x86_64: {
+ cflags: ["-fPIC"],
+ },
+ arm: {
+ cflags: ["-Wall"],
+ },
+ arm64: {
+ cflags: ["-Wall"],
+ },
+ },
+ bazel_module: { bp2build_available: true },
+}
+`,
+ expectedBazelTargets: []string{
+ `cc_object(
+ name = "foo",
+ copts = [
+ "-fno-addrsig",
+ ] + select({
+ "@bazel_tools//platforms:arm": [
+ "-Wall",
+ ],
+ "@bazel_tools//platforms:aarch64": [
+ "-Wall",
+ ],
+ "@bazel_tools//platforms:x86_32": [
+ "-fPIC",
+ ],
+ "@bazel_tools//platforms:x86_64": [
+ "-fPIC",
+ ],
+ "//conditions:default": [
+ ],
+ }),
+)`,
+ },
+ },
+ }
+
+ dir := "."
+ for _, testCase := range testCases {
+ filesystem := make(map[string][]byte)
+ toParse := []string{
+ "Android.bp",
+ }
+ config := android.TestConfig(buildDir, nil, testCase.blueprint, filesystem)
+ ctx := android.NewTestContext(config)
+ // Always register cc_defaults module factory
+ ctx.RegisterModuleType("cc_defaults", func() android.Module { return cc.DefaultsFactory() })
+
+ ctx.RegisterModuleType(testCase.moduleTypeUnderTest, testCase.moduleTypeUnderTestFactory)
+ ctx.RegisterBp2BuildMutator(testCase.moduleTypeUnderTest, testCase.moduleTypeUnderTestBp2BuildMutator)
+ ctx.RegisterForBazelConversion()
+
+ _, errs := ctx.ParseFileList(dir, toParse)
+ if Errored(t, testCase.description, errs) {
+ continue
+ }
+ _, errs = ctx.ResolveDependencies(config)
+ if Errored(t, testCase.description, errs) {
+ continue
+ }
+
+ codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
+ bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+ if actualCount, expectedCount := len(bazelTargets), len(testCase.expectedBazelTargets); actualCount != expectedCount {
+ fmt.Println(bazelTargets)
+ t.Errorf("%s: Expected %d bazel target, got %d", testCase.description, expectedCount, actualCount)
+ } else {
+ for i, target := range bazelTargets {
+ if w, g := testCase.expectedBazelTargets[i], target.content; w != g {
+ t.Errorf(
+ "%s: Expected generated Bazel target to be '%s', got '%s'",
+ testCase.description,
+ w,
+ g,
+ )
+ }
+ }
+ }
+ }
+}
diff --git a/bp2build/configurability.go b/bp2build/configurability.go
new file mode 100644
index 0000000..47cf3c6
--- /dev/null
+++ b/bp2build/configurability.go
@@ -0,0 +1,15 @@
+package bp2build
+
+import "android/soong/android"
+
+// Configurability support for bp2build.
+
+var (
+ // A map of architectures to the Bazel label of the constraint_value.
+ platformArchMap = map[android.ArchType]string{
+ android.Arm: "@bazel_tools//platforms:arm",
+ android.Arm64: "@bazel_tools//platforms:aarch64",
+ android.X86: "@bazel_tools//platforms:x86_32",
+ android.X86_64: "@bazel_tools//platforms:x86_64",
+ }
+)
diff --git a/cc/object.go b/cc/object.go
index 140a066..32347b8 100644
--- a/cc/object.go
+++ b/cc/object.go
@@ -93,7 +93,7 @@
type bazelObjectAttributes struct {
Srcs bazel.LabelList
Deps bazel.LabelList
- Copts []string
+ Copts bazel.StringListAttribute
Local_include_dirs []string
}
@@ -133,13 +133,14 @@
ctx.ModuleErrorf("compiler must not be nil for a cc_object module")
}
- var copts []string
+ // Set arch-specific configurable attributes
+ var copts bazel.StringListAttribute
var srcs []string
var excludeSrcs []string
var localIncludeDirs []string
for _, props := range m.compiler.compilerProps() {
if baseCompilerProps, ok := props.(*BaseCompilerProperties); ok {
- copts = baseCompilerProps.Cflags
+ copts.Value = baseCompilerProps.Cflags
srcs = baseCompilerProps.Srcs
excludeSrcs = baseCompilerProps.Exclude_srcs
localIncludeDirs = baseCompilerProps.Local_include_dirs
@@ -154,6 +155,13 @@
}
}
+ for arch, p := range m.GetArchProperties(&BaseCompilerProperties{}) {
+ if cProps, ok := p.(*BaseCompilerProperties); ok {
+ copts.SetValueForArch(arch.Name, cProps.Cflags)
+ }
+ }
+ copts.SetValueForArch("default", []string{})
+
attrs := &bazelObjectAttributes{
Srcs: android.BazelLabelForModuleSrcExcludes(ctx, srcs, excludeSrcs),
Deps: deps,