github.com/westcoastroms/westcoastroms-build@v0.0.0-20190928114312-2350e5a73030/build/soong/android/env.go (about)

     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  
    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  
    31  var originalEnv map[string]string
    32  
    33  func 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  
    44  func EnvSingleton() Singleton {
    45  	return &envSingleton{}
    46  }
    47  
    48  type envSingleton struct{}
    49  
    50  func (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  }