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 15 package android 16 17 import ( 18 "os" 19 "strings" 20 21 "android/soong/env" 22 23 "github.com/google/blueprint" 24 ) 25 26 // This file supports dependencies on environment variables. During build manifest generation, 27 // any dependency on an environment variable is added to a list. During the singleton phase 28 // a JSON file is written containing the current value of all used environment variables. 29 // The next time the top-level build script is run, it uses the soong_env executable to 30 // compare the contents of the environment variables, rewriting the file if necessary to cause 31 // a manifest regeneration. 32 33 var originalEnv map[string]string 34 35 func init() { 36 originalEnv = make(map[string]string) 37 for _, env := range os.Environ() { 38 idx := strings.IndexRune(env, '=') 39 if idx != -1 { 40 originalEnv[env[:idx]] = env[idx+1:] 41 } 42 } 43 os.Clearenv() 44 } 45 46 func EnvSingleton() blueprint.Singleton { 47 return &envSingleton{} 48 } 49 50 type envSingleton struct{} 51 52 func (c *envSingleton) GenerateBuildActions(ctx blueprint.SingletonContext) { 53 envDeps := ctx.Config().(Config).EnvDeps() 54 55 envFile := PathForOutput(ctx, ".soong.environment") 56 if ctx.Failed() { 57 return 58 } 59 60 err := env.WriteEnvFile(envFile.String(), envDeps) 61 if err != nil { 62 ctx.Errorf(err.Error()) 63 } 64 65 ctx.AddNinjaFileDeps(envFile.String()) 66 } 67
