Technical data

22
Chapter 1: Compiling, Linking, and Running Programs
Run-Time Error Handling
When the Fortran run-time system detects an error, the following action
takes place:
• A message describing the error is written to the standard error unit
(unit 0). See Appendix A, “Run-Time Error Messages,” for a list of the
error messages.
• A core file is produced if the f77_dump_flag environment variable is
set, as described in Appendix A, “Run-Time Error Messages.”. You can
use dbx or edge to inspect this file and determine the state of the
program at termination. For more information, see the dbx Reference
Manual and the edge(1) manual page.
To invoke dbx using the core file, enter the following:
% dbx binary-file core
where binary-file is the name of the object file output (the default is
a.out). For more information on dbx, see “Debugging” on page 16.
Trap Handling
The library libfpe.a provides two methods for handling floating point
exceptions: the subroutine handle_sigfpes and the environment variable
TRAP_FPE. Both methods provide mechanisms for handling and
classifying floating point exceptions, and for substituting new values. They
also provide mechanisms to count, trace, exit, or abort on enabled
exceptions. See the handle_sigfpes(3F) manual page for more information.