LF95 Linux User's Guide - Lahey Computer Systems

4 Command-LineDebugging with fdbfdb is a command-line symbolic source-level debugger for Fortran 95, and assemblyprograms.Before debugging your program you must compile it using the -g option (see“Compiler andLinker Options” on page 16). The -g option creates additional symbolic debugging informationwithin the executable code.fdb is not compatible with the debug information generated by gcc, the GNU C compiler. Itis, however, possible to debug LF64 programs using gdb (GNU debugger), subject to the followingrestrictions:Fortran 90/95 specifications are not supported in gdb.The contents of COMMON can only be examined in gdb by examining memory andinterpreting the values there.Fortran procedures must be specified as lowercase with trailing underscore (_). Youcan step through module procedures but you cannot set a breakpoint or examine thevalues of variables or parameters.Fortran variables must be specified in capital letters.Starting fdbTo start fdb type:fdb [exefile] [corefile]Where: exefile is the name of an executable file compiled with the -g option, and corefile isthe name of the core file (if any) produced by abnormal termination of the executable. Ifexefile is not supplied, then fdb will assume the executable file is a.out. If corefile is notsupplied, then fdb will assume the core dump file is core.Lahey/Fujitsu Linux64 Fortran User’s Guide 65