These are hooks for DBX format.
A C statement to output DBX debugging information before code for line number line of the current source file to the stdio stream stream. counter is the number of time the macro was invoked, including the current invocation; it is intended to generate unique labels in the assembly output.
This macro should not be defined if the default output is correct, or if it can be made correct by defining
DBX_LINES_FUNCTION_RELATIVE
.