Add PropertyCustomizer
Allow any module factory to insert a PropertyCustomizer on the module,
which will be called before any other mutators. The PropertyCustomizer
can append or prepend to any properties, allowing module types to extend
other module types by modifying the public, stable interface provided by
the properties.
Change-Id: Idff02be80d939a70df1c6bbccffdd1f04ff975d2
diff --git a/android/customizer.go b/android/customizer.go
new file mode 100644
index 0000000..056880d
--- /dev/null
+++ b/android/customizer.go
@@ -0,0 +1,77 @@
+// Copyright 2016 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 "github.com/google/blueprint/proptools"
+
+type CustomizePropertiesContext interface {
+ BaseContext
+ AppendProperties(...interface{})
+ PrependProperties(...interface{})
+}
+
+type customizePropertiesContext struct {
+ BaseContext
+
+ module *ModuleBase
+}
+
+type PropertyCustomizer interface {
+ CustomizeProperties(CustomizePropertiesContext)
+}
+
+func customizerMutator(ctx TopDownMutatorContext) {
+ if m, ok := ctx.Module().(Module); ok {
+ a := m.base()
+ if len(a.customizers) > 0 {
+ mctx := &customizePropertiesContext{
+ BaseContext: ctx,
+ module: a,
+ }
+ for _, c := range a.customizers {
+ c.CustomizeProperties(mctx)
+ if mctx.Failed() {
+ return
+ }
+ }
+ }
+ }
+}
+
+func (ctx *customizePropertiesContext) AppendProperties(props ...interface{}) {
+ for _, p := range props {
+ err := proptools.AppendMatchingProperties(ctx.module.customizableProperties, p, nil)
+ if err != nil {
+ if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok {
+ ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error())
+ } else {
+ panic(err)
+ }
+ }
+ }
+}
+
+func (ctx *customizePropertiesContext) PrependProperties(props ...interface{}) {
+ for _, p := range props {
+ err := proptools.PrependMatchingProperties(ctx.module.customizableProperties, p, nil)
+ if err != nil {
+ if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok {
+ ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error())
+ } else {
+ panic(err)
+ }
+ }
+ }
+}