— Macro: DBX_OUTPUT_MAIN_SOURCE_FILENAME (stream, name)

A C statement to output DBX debugging information to the stdio stream stream which indicates that file name is the main source file—the file specified as the input file for compilation. This macro is called only once, at the beginning of compilation.

This macro need not be defined if the standard form of output for DBX debugging information is appropriate.

— Macro: DBX_OUTPUT_MAIN_SOURCE_DIRECTORY (stream, name)

A C statement to output DBX debugging information to the stdio stream stream which indicates that the current directory during compilation is named name.

This macro need not be defined if the standard form of output for DBX debugging information is appropriate.

— Macro: DBX_OUTPUT_MAIN_SOURCE_FILE_END (stream, name)

A C statement to output DBX debugging information at the end of compilation of the main source file name.

If you don't define this macro, nothing special is output at the end of compilation, which is correct for most machines.