Misc fixes for test problems (#2751)

* service/dap: remove deadlock in TestLaunchDebugRequest

Fixes #2746

* terminal: fix TestScopePrefix flakiness

When there are more than 10 frames api.PrintStack will prefix the
output with spaces to right justify the frame number, which confuses
TestScopePrefix.

* _scripts: pass -buildvcs for Go 1.18 and later on TeamCity

Go 1.18 will try to stamp builds with the VCS version, this doesn't
work on TeamCity because the checkout isn't a valid repository (but
looks like it).
Pass -buildvcs=false to disable this feature.

* proc: switch to goroutine stack if first frame's func can not be found

If the first frame on the system stack can not be resolved to a
function switch directly to the goroutine stack.

_scripts/test_linux.sh

@@ -53,4 +53,12 @@ echo "$GOROOT"
 echo "$GOPATH"
 cd delve
 
+# Starting with go1.18 'go build' and 'go run' will try to stamp the build
+# with the current VCS revision, which does not work with TeamCity
+if [ "$version" = "gotip" ]; then
+	export GOFLAGS=-buildvcs=false
+elif [ ${version:4} -gt 17 ]; then
+	export GOFLAGS=-buildvcs=false
+fi
+
 make test

pkg/proc/amd64_arch.go

@@ -131,6 +131,10 @@ const amd64cgocallSPOffsetSaveSlot = 0x28
 
 func amd64SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
 	if it.frame.Current.Fn == nil {
+		if it.systemstack && it.g != nil && it.top {
+			it.switchToGoroutineStack()
+			return true
+		}
 		return false
 	}
 	switch it.frame.Current.Fn.Name {

pkg/proc/arm64_arch.go

@@ -132,6 +132,10 @@ const arm64cgocallSPOffsetSaveSlot = 0x8
 const prevG0schedSPOffsetSaveSlot = 0x10
 
 func arm64SwitchStack(it *stackIterator, callFrameRegs *op.DwarfRegisters) bool {
+	if it.frame.Current.Fn == nil && it.systemstack && it.g != nil && it.top {
+		it.switchToGoroutineStack()
+		return true
+	}
 	if it.frame.Current.Fn != nil {
 		switch it.frame.Current.Fn.Name {
 		case "runtime.asmcgocall", "runtime.cgocallback_gofunc", "runtime.sigpanic", "runtime.cgocallback":

pkg/proc/i386_arch.go

@@ -117,6 +117,10 @@ func i386FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryI
 // SwitchStack will use the current frame to determine if it's time to
 func i386SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
 	if it.frame.Current.Fn == nil {
+		if it.systemstack && it.g != nil && it.top {
+			it.switchToGoroutineStack()
+			return true
+		}
 		return false
 	}
 	switch it.frame.Current.Fn.Name {

pkg/proc/proc_test.go

@@ -5408,7 +5408,7 @@ func TestWatchpointsBasic(t *testing.T) {
 			t.Fatal("breakpoint not set")
 		}
 
-		p.ClearBreakpoint(bp.Addr)
+		assertNoError(p.ClearBreakpoint(bp.Addr), t, "ClearBreakpoint")
 
 		assertNoError(p.Continue(), t, "Continue 2")
 		assertLineNumber(p, t, 21, "Continue 2") // Position 2

pkg/terminal/command_test.go

@@ -402,6 +402,7 @@ func TestScopePrefix(t *testing.T) {
 			stackOut := strings.Split(term.MustExec(fmt.Sprintf("goroutine %d stack", gid)), "\n")
 			fid := -1
 			for _, line := range stackOut {
+				line = strings.TrimLeft(line, " ")
 				space := strings.Index(line, " ")
 				if space < 0 {
 					continue
@@ -417,7 +418,7 @@ func TestScopePrefix(t *testing.T) {
 				}
 			}
 			if fid < 0 {
-				t.Fatalf("Could not find frame for goroutine %d: %v", gid, stackOut)
+				t.Fatalf("Could not find frame for goroutine %d: %q", gid, stackOut)
 			}
 			term.AssertExec(fmt.Sprintf("goroutine     %d    frame     %d     locals", gid, fid), "(no locals)\n")
 			argsOut := strings.Split(term.MustExec(fmt.Sprintf("goroutine %d frame %d args", gid, fid)), "\n")

service/dap/server_test.go

@@ -4734,6 +4734,15 @@ func TestLaunchDebugRequest(t *testing.T) {
 	rescueStderr := os.Stderr
 	r, w, _ := os.Pipe()
 	os.Stderr = w
+	done := make(chan struct{})
+
+	var err []byte
+
+	go func() {
+		err, _ = ioutil.ReadAll(r)
+		t.Log(string(err))
+		close(done)
+	}()
 
 	tmpBin := "__tmpBin"
 	runTest(t, "increment", func(client *daptest.Client, fixture protest.Fixture) {
@@ -4748,8 +4757,7 @@ func TestLaunchDebugRequest(t *testing.T) {
 	time.Sleep(100 * time.Millisecond)
 
 	w.Close()
-	err, _ := ioutil.ReadAll(r)
-	t.Log(string(err))
+	<-done
 	os.Stderr = rescueStderr
 
 	rmErrRe, _ := regexp.Compile(`could not remove .*\n`)