123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168 |
- // Copyright 2019 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 android
- import (
- "fmt"
- "reflect"
- "github.com/google/blueprint/proptools"
- )
- // This file implements support for automatically adding dependencies on any module referenced
- // with the ":module" module reference syntax in a property that is annotated with `android:"path"`.
- // The dependency is used by android.PathForModuleSrc to convert the module reference into the path
- // to the output file of the referenced module.
- func registerPathDepsMutator(ctx RegisterMutatorsContext) {
- ctx.BottomUp("pathdeps", pathDepsMutator).Parallel()
- }
- // The pathDepsMutator automatically adds dependencies on any module that is listed with the
- // ":module" module reference syntax in a property that is tagged with `android:"path"`.
- func pathDepsMutator(ctx BottomUpMutatorContext) {
- props := ctx.Module().base().GetProperties()
- addPathDepsForProps(ctx, props)
- }
- func addPathDepsForProps(ctx BottomUpMutatorContext, props []interface{}) {
- // Iterate through each property struct of the module extracting the contents of all properties
- // tagged with `android:"path"`.
- var pathProperties []string
- for _, ps := range props {
- pathProperties = append(pathProperties, pathPropertiesForPropertyStruct(ps)...)
- }
- // Remove duplicates to avoid multiple dependencies.
- pathProperties = FirstUniqueStrings(pathProperties)
- // Add dependencies to anything that is a module reference.
- for _, s := range pathProperties {
- if m, t := SrcIsModuleWithTag(s); m != "" {
- ctx.AddDependency(ctx.Module(), sourceOrOutputDepTag(m, t), m)
- }
- }
- }
- // pathPropertiesForPropertyStruct uses the indexes of properties that are tagged with
- // android:"path" to extract all their values from a property struct, returning them as a single
- // slice of strings.
- func pathPropertiesForPropertyStruct(ps interface{}) []string {
- v := reflect.ValueOf(ps)
- if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
- panic(fmt.Errorf("type %s is not a pointer to a struct", v.Type()))
- }
- // If the property struct is a nil pointer it can't have any paths set in it.
- if v.IsNil() {
- return nil
- }
- // v is now the reflect.Value for the concrete property struct.
- v = v.Elem()
- // Get or create the list of indexes of properties that are tagged with `android:"path"`.
- pathPropertyIndexes := pathPropertyIndexesForPropertyStruct(ps)
- var ret []string
- for _, i := range pathPropertyIndexes {
- var values []reflect.Value
- fieldsByIndex(v, i, &values)
- for _, sv := range values {
- if !sv.IsValid() {
- // Skip properties inside a nil pointer.
- continue
- }
- // If the field is a non-nil pointer step into it.
- if sv.Kind() == reflect.Ptr {
- if sv.IsNil() {
- continue
- }
- sv = sv.Elem()
- }
- // Collect paths from all strings and slices of strings.
- switch sv.Kind() {
- case reflect.String:
- ret = append(ret, sv.String())
- case reflect.Slice:
- ret = append(ret, sv.Interface().([]string)...)
- default:
- panic(fmt.Errorf(`field %s in type %s has tag android:"path" but is not a string or slice of strings, it is a %s`,
- v.Type().FieldByIndex(i).Name, v.Type(), sv.Type()))
- }
- }
- }
- return ret
- }
- // fieldsByIndex is similar to reflect.Value.FieldByIndex, but is more robust: it doesn't track
- // nil pointers and it returns multiple values when there's slice of struct.
- func fieldsByIndex(v reflect.Value, index []int, values *[]reflect.Value) {
- // leaf case
- if len(index) == 1 {
- if isSliceOfStruct(v) {
- for i := 0; i < v.Len(); i++ {
- *values = append(*values, v.Index(i).Field(index[0]))
- }
- } else {
- // Dereference it if it's a pointer.
- if v.Kind() == reflect.Ptr {
- if v.IsNil() {
- return
- }
- v = v.Elem()
- }
- *values = append(*values, v.Field(index[0]))
- }
- return
- }
- // recursion
- if v.Kind() == reflect.Ptr {
- // don't track nil pointer
- if v.IsNil() {
- return
- }
- v = v.Elem()
- } else if isSliceOfStruct(v) {
- // do the recursion for all elements
- for i := 0; i < v.Len(); i++ {
- fieldsByIndex(v.Index(i).Field(index[0]), index[1:], values)
- }
- return
- }
- fieldsByIndex(v.Field(index[0]), index[1:], values)
- return
- }
- func isSliceOfStruct(v reflect.Value) bool {
- return v.Kind() == reflect.Slice && v.Type().Elem().Kind() == reflect.Struct
- }
- var pathPropertyIndexesCache OncePer
- // pathPropertyIndexesForPropertyStruct returns a list of all of the indexes of properties in
- // property struct type that are tagged with `android:"path"`. Each index is a []int suitable for
- // passing to reflect.Value.FieldByIndex. The value is cached in a global cache by type.
- func pathPropertyIndexesForPropertyStruct(ps interface{}) [][]int {
- key := NewCustomOnceKey(reflect.TypeOf(ps))
- return pathPropertyIndexesCache.Once(key, func() interface{} {
- return proptools.PropertyIndexesWithTag(ps, "android", "path")
- }).([][]int)
- }
|