dbx might not be able to find your C source files or C++ source files in the following circumstances:
If your source files are not in the same location as they were when you compiled them
If you compiled your source files on a different system than the one on which you are running dbx and the compile directory does not have the same path name
In such cases, use the pathmap command (see pathmap Command) to map one path name to another so that dbx can find your files.