The prefix area of the Source window is the leftmost column in the main area of the window. In a source view, the values in the prefix area correspond to the line numbers in the current source file. In a disassembly view, they correspond to the hexadecimal addresses of machine language instructions. In a mixed view, both line numbers and hex addresses are shown.
You can use the prefix area in the following ways:
Breakpoints are indicated in the prefix area by reverse red highlighting.