GDB/MI Frame Information (Debugging with GDB)

Response from many MI commands includes an information about stack frame. This information is a tuple that may have the following fields:

level: The level of the stack frame. The innermost frame has the level of zero. This field is always present.
func: The name of the function corresponding to the frame. This field may be absent if GDB is unable to determine the function name.
addr: The code address for the frame. This field is always present.
file: The name of the source files that correspond to the frame’s code address. This field may be absent.
line: The source line corresponding to the frames’ code address. This field may be absent.
from: The name of the binary file (either executable or shared library) the corresponds to the frame’s code address. This field may be absent.