common/variable.go

// Copyright 2015 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 common

import (
	"fmt"
	"reflect"
	"strings"

	"android/soong"

	"github.com/google/blueprint"
	"github.com/google/blueprint/proptools"
)

func init() {
	soong.RegisterEarlyMutator("variable", VariableMutator)
}

type variableProperties struct {
	Product_variables struct {
		Device_uses_dlmalloc struct {
			Cflags []string
			Srcs   []string
		}
		Device_uses_jemalloc struct {
			Cflags            []string
			Srcs              []string
			Whole_static_libs []string
			Include_dirs      []string
		}
		Dlmalloc_alignment struct {
			Cflags []string
		}
	}
}

var zeroProductVariables variableProperties

type productVariables struct {
	Device_uses_jemalloc *bool `json:",omitempty"`
	Device_uses_dlmalloc *bool `json:",omitempty"`
	Dlmalloc_alignment   *int  `json:",omitempty"`
}

func boolPtr(v bool) *bool {
	return &v
}

func (productVariables) DefaultConfig() jsonConfigurable {
	v := productVariables{
		Device_uses_jemalloc: boolPtr(true),
	}
	return v
}

func VariableMutator(mctx blueprint.EarlyMutatorContext) {
	var module AndroidModule
	var ok bool
	if module, ok = mctx.Module().(AndroidModule); !ok {
		return
	}

	// TODO: depend on config variable, create variants, propagate variants up tree
	a := module.base()
	variableValues := reflect.ValueOf(a.variableProperties.Product_variables)
	zeroValues := reflect.ValueOf(zeroProductVariables.Product_variables)

	for i := 0; i < variableValues.NumField(); i++ {
		variableValue := variableValues.Field(i)
		zeroValue := zeroValues.Field(i)
		name := variableValues.Type().Field(i).Name
		property := "product_variables." + proptools.PropertyNameForField(name)

		// Check that the variable was set for the product
		val := reflect.ValueOf(mctx.Config().(Config).ProductVariables).FieldByName(name)
		if !val.IsValid() || val.Kind() != reflect.Ptr || val.IsNil() {
			continue
		}

		val = val.Elem()

		// For bools, check that the value is true
		if val.Kind() == reflect.Bool && val.Bool() == false {
			continue
		}

		// Check if any properties were set for the module
		if reflect.DeepEqual(variableValue.Interface(), zeroValue.Interface()) {
			continue
		}

		a.setVariableProperties(mctx, property, variableValue, val.Interface())
	}
}

func (a *AndroidModuleBase) setVariableProperties(ctx blueprint.EarlyMutatorContext,
	prefix string, productVariablePropertyValue reflect.Value, variableValue interface{}) {

	generalPropertyValues := make([]reflect.Value, len(a.generalProperties))
	for i := range a.generalProperties {
		generalPropertyValues[i] = reflect.ValueOf(a.generalProperties[i]).Elem()
	}

	if variableValue != nil {
		printfIntoProperties(productVariablePropertyValue, variableValue)
	}

	extendProperties(ctx, "", prefix, generalPropertyValues, productVariablePropertyValue, nil)
}

func printfIntoProperties(productVariablePropertyValue reflect.Value, variableValue interface{}) {
	for i := 0; i < productVariablePropertyValue.NumField(); i++ {
		propertyValue := productVariablePropertyValue.Field(i)
		switch propertyValue.Kind() {
		case reflect.String:
			printfIntoProperty(propertyValue, variableValue)
		case reflect.Slice:
			for j := 0; j < propertyValue.Len(); j++ {
				printfIntoProperty(propertyValue.Index(j), variableValue)
			}
		case reflect.Struct:
			printfIntoProperties(propertyValue, variableValue)
		default:
			panic(fmt.Errorf("unsupported field kind %q", propertyValue.Kind()))
		}
	}
}

func printfIntoProperty(propertyValue reflect.Value, variableValue interface{}) {
	s := propertyValue.String()
	// For now, we only support int formats
	var i int
	if strings.Contains(s, "%d") {
		switch v := variableValue.(type) {
		case int:
			i = v
		case bool:
			if v {
				i = 1
			}
		default:
			panic(fmt.Errorf("unsupported type %T", variableValue))
		}
		propertyValue.Set(reflect.ValueOf(fmt.Sprintf(s, i)))
	}
}