}
		parent = parent.parent
	}

	return raceErrors
}

// callerName gives the function name (qualified with a package path)
// for the caller after skip frames (where 0 means the current function).
func callerName(skip int) string {
	var pc [1]uintptr
	n := runtime.Callers(skip+2, pc[:]) // skip + runtime.Callers + callerName
	if n == 0 {
		panic("testing: zero callers found")
	}

	// instead of the caller.
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.helperPCs == nil {
		f.helperPCs = make(map[uintptr]struct{})
	}
	// repeating code from callerName here to save walking a stack frame
	var pc [1]uintptr
	n := runtime.Callers(2, pc[:]) // skip runtime.Callers + Helper
	if n == 0 {
		panic("testing: zero callers found")
	}