68f55102da
Ninja can't depend on environment variables, so modifying build behavior based on environment variables requires coordinating between the soong script that invokes ninja and the soong_build manifest generator. Allow any module to call Config.Getenv to get the contents of an environment variable while registering a dependency on it. After all modules have been processed write out the state of all used environment variables to a JSON file called .soong.environment. During the next build the soong script will use the soong_env tool to compare the contents of .soong.environment to the current environment, and force a build manifest regeneration by deleting the .soong.environment file if any variables have changed. Change-Id: Id0d81933a857bc2fc1cd7a393a3c6cec73dc4824
97 lines
2.1 KiB
Go
97 lines
2.1 KiB
Go
// Copyright 2015 Google Inc. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// env implements the environment JSON file handling for the soong_env command line tool run before
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// the builder and for the env writer in the builder.
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package env
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import (
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"encoding/json"
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"fmt"
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"io/ioutil"
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"os"
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"sort"
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)
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type envFileEntry struct{ Key, Value string }
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type envFileData []envFileEntry
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func WriteEnvFile(filename string, envDeps map[string]string) error {
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contents := make(envFileData, 0, len(envDeps))
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for key, value := range envDeps {
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contents = append(contents, envFileEntry{key, value})
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}
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sort.Sort(contents)
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data, err := json.MarshalIndent(contents, "", " ")
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if err != nil {
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return err
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}
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data = append(data, '\n')
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err = ioutil.WriteFile(filename, data, 0664)
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if err != nil {
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return err
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}
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return nil
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}
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func StaleEnvFile(filename string) (bool, error) {
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data, err := ioutil.ReadFile(filename)
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if err != nil {
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return true, err
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}
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var contents envFileData
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err = json.Unmarshal(data, &contents)
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if err != nil {
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return true, err
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}
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var changed []string
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for _, entry := range contents {
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key := entry.Key
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old := entry.Value
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cur := os.Getenv(key)
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if old != cur {
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changed = append(changed, fmt.Sprintf("%s (%q -> %q)", key, old, cur))
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}
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}
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if len(changed) > 0 {
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fmt.Printf("environment variables changed value:\n")
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for _, s := range changed {
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fmt.Printf(" %s\n", s)
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}
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return true, nil
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}
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return false, nil
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}
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func (e envFileData) Len() int {
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return len(e)
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}
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func (e envFileData) Less(i, j int) bool {
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return e[i].Key < e[j].Key
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}
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func (e envFileData) Swap(i, j int) {
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e[i], e[j] = e[j], e[i]
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}
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