Fix envDeps initialization and locking

If Config.GetEnv was called when envDeps was uninitialized (for
example in a test) it would panic, which if recovered (for example in
a test) would cause it to continue without unlocking the mutex, and
could later deadlock.  Fix the initialization by initializing in
GetEnv if necessary, and use defer to avoid holding the mutex after
a panic.

Test: soong tests
Change-Id: I453522faaf47ff6fbc4702345cfe177100bdc522

1 files changed, 5 insertions, 3 deletions

diff --git a/android/config.go b/android/config.go
index 36034775..76635b39 100644
--- a/android/config.go
+++ b/android/config.go
@@ -177,7 +177,6 @@ func NewConfig(srcDir, buildDir string) (Config, error) {
 
 		srcDir:   srcDir,
 		buildDir: buildDir,
-		envDeps:  make(map[string]string),
 
 		deviceConfig: &deviceConfig{},
 	}
@@ -281,6 +280,10 @@ func (c *config) Getenv(key string) string {
 	var val string
 	var exists bool
 	c.envLock.Lock()
+	defer c.envLock.Unlock()
+	if c.envDeps == nil {
+		c.envDeps = make(map[string]string)
+	}
 	if val, exists = c.envDeps[key]; !exists {
 		if c.envFrozen {
 			panic("Cannot access new environment variables after envdeps are frozen")
@@ -288,7 +291,6 @@ func (c *config) Getenv(key string) string {
 		val = os.Getenv(key)
 		c.envDeps[key] = val
 	}
-	c.envLock.Unlock()
 	return val
 }
 
@@ -312,8 +314,8 @@ func (c *config) IsEnvFalse(key string) bool {
 
 func (c *config) EnvDeps() map[string]string {
 	c.envLock.Lock()
+	defer c.envLock.Unlock()
 	c.envFrozen = true
-	c.envLock.Unlock()
 	return c.envDeps
 }