Sandbox soong_build by changing to root directory

Store the current working directory and then change to the root
directory so that all file accesses must go through helpers in
the android package that properly track dependencies.

Fixes: 146437378
Test: m checkbuild
Change-Id: I12a0f907753fefd1997ab8b4ea2ac331234093cf

1 files changed, 3 insertions, 8 deletions

diff --git a/env/env.go b/env/env.go
index bf58a991..a98e1f6a 100644
--- a/env/env.go
+++ b/env/env.go
@@ -27,7 +27,7 @@ import (
 type envFileEntry struct{ Key, Value string }
 type envFileData []envFileEntry
 
-func WriteEnvFile(filename string, envDeps map[string]string) error {
+func EnvFileContents(envDeps map[string]string) ([]byte, error) {
 	contents := make(envFileData, 0, len(envDeps))
 	for key, value := range envDeps {
 		contents = append(contents, envFileEntry{key, value})
@@ -37,17 +37,12 @@ func WriteEnvFile(filename string, envDeps map[string]string) error {
 
 	data, err := json.MarshalIndent(contents, "", "    ")
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	data = append(data, '\n')
 
-	err = ioutil.WriteFile(filename, data, 0664)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return data, nil
 }
 
 func StaleEnvFile(filename string) (bool, error) {