Revert "cmd/go, misc: rework cwd handling for iOS tests"

This reverts commit 593ea3b3.

Replaced by a improved strategy later in the CL relation chain.

Change-Id: I6963e4d1bf38e7028cf545a953e28054d83548
Change-Id: I6963e4d1bf38e7028cf545a953e28054d8354870
Reviewed-on: https://go-review.googlesource.com/36067Reviewed-by: David Crawshaw <crawshaw@golang.org>

misc/ios/go_darwin_arm_exec.go

@@ -212,11 +212,6 @@ func run(bin string, args []string) (err error) {
 	var opts options
 	opts, args = parseArgs(args)
 
-	// Pass the suffix for the current working directory as the
-	// first argument to the test. For iOS, cmd/go generates
-	// special handling of this argument.
-	args = append([]string{"cwdSuffix=" + pkgpath}, args...)
-
 	// ios-deploy invokes lldb to give us a shell session with the app.
 	s, err := newSession(appdir, args, opts)
 	if err != nil {
@@ -254,6 +249,15 @@ func run(bin string, args []string) (err error) {
 
 	s.doCmd("run", "stop reason = signal SIGUSR2", 20*time.Second)
 
+	// Move the current working directory into the faux gopath.
+	if pkgpath != "src" {
+		s.do(`breakpoint delete 1`)
+		s.do(`expr char* $mem = (char*)malloc(512)`)
+		s.do(`expr $mem = (char*)getwd($mem, 512)`)
+		s.do(`expr $mem = (char*)strcat($mem, "/` + pkgpath + `")`)
+		s.do(`call (void)chdir($mem)`)
+	}
+
 	startTestsLen := s.out.Len()
 	fmt.Fprintln(s.in, `process continue`)
 

src/cmd/go/internal/test/test.go

@@ -1562,28 +1562,12 @@ func coverRegisterFile(fileName string, counter []uint32, pos []uint32, numStmts
 func main() {
 {{if .IsIOS}}
 	// Send a SIGUSR2, which will be intercepted by LLDB to
-	// tell the test harness that installation was successful.
-	// See misc/ios/go_darwin_arm_exec.go.
+	// tell the test harness that installation was successful,
+	// and to give the exec script a chance set the current
+	// working directory. See misc/ios/go_darwin_arm_exec.go.
 	signal.Notify(make(chan os.Signal), syscall.SIGUSR2)
 	syscall.Kill(0, syscall.SIGUSR2)
 	signal.Reset(syscall.SIGUSR2)
-
-	// The first argument supplied to an iOS test is an offset
-	// suffix for the current working directory.
-	// Process it here, and remove it from os.Args.
-	const hdr = "cwdSuffix="
-	if len(os.Args) < 2 || len(os.Args[1]) <= len(hdr) || os.Args[1][:len(hdr)] != hdr {
-		panic("iOS test not passed a working directory suffix")
-	}
-	suffix := os.Args[1][len(hdr):]
-	dir, err := os.Getwd()
-	if err != nil {
-		panic(err)
-	}
-	if err := os.Chdir(dir + "/" + suffix); err != nil {
-		panic(err)
-	}
-	os.Args = append([]string{os.Args[0]}, os.Args[2:]...)
 {{end}}
 
 {{if .CoverEnabled}}