1// Copyright 2015 Google Inc. All rights reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package android 16 17import ( 18 "os" 19 "strings" 20 21 "android/soong/env" 22) 23 24// This file supports dependencies on environment variables. During build manifest generation, 25// any dependency on an environment variable is added to a list. During the singleton phase 26// a JSON file is written containing the current value of all used environment variables. 27// The next time the top-level build script is run, it uses the soong_env executable to 28// compare the contents of the environment variables, rewriting the file if necessary to cause 29// a manifest regeneration. 30 31var originalEnv map[string]string 32 33func init() { 34 originalEnv = make(map[string]string) 35 for _, env := range os.Environ() { 36 idx := strings.IndexRune(env, '=') 37 if idx != -1 { 38 originalEnv[env[:idx]] = env[idx+1:] 39 } 40 } 41 os.Clearenv() 42} 43 44func EnvSingleton() Singleton { 45 return &envSingleton{} 46} 47 48type envSingleton struct{} 49 50func (c *envSingleton) GenerateBuildActions(ctx SingletonContext) { 51 envDeps := ctx.Config().EnvDeps() 52 53 envFile := PathForOutput(ctx, ".soong.environment") 54 if ctx.Failed() { 55 return 56 } 57 58 err := env.WriteEnvFile(envFile.String(), envDeps) 59 if err != nil { 60 ctx.Errorf(err.Error()) 61 } 62 63 ctx.AddNinjaFileDeps(envFile.String()) 64} 65