test/run: use correct $PWD to make os.Getwd less expensive
The commands being run are 'go tool this' and 'go tool that',
and the go command will call Getwd during its init.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7336045
diff --git a/test/run.go b/test/run.go
index 36c8b7a..5e167d6 100644
--- a/test/run.go
+++ b/test/run.go
@@ -433,6 +433,7 @@
cmd.Stderr = &buf
if useTmp {
cmd.Dir = t.tempDir
+ cmd.Env = envForDir(cmd.Dir)
}
err := cmd.Run()
if err != nil {
@@ -828,3 +829,20 @@
assertNot(shouldTest("// +build arm 386", "linux", "amd64"))
assert(shouldTest("// This is a test.", "os", "arch"))
}
+
+// envForDir returns a copy of the environment
+// suitable for running in the given directory.
+// The environment is the current process's environment
+// but with an updated $PWD, so that an os.Getwd in the
+// child will be faster.
+func envForDir(dir string) []string {
+ env := os.Environ()
+ for i, kv := range env {
+ if strings.HasPrefix(kv, "PWD=") {
+ env[i] = "PWD=" + dir
+ return env
+ }
+ }
+ env = append(env, "PWD="+dir)
+ return env
+}
