XL Fortran Enterprise Edition for AIX : User's Guide - IBM

Input/Output Errors
If the error detected is an input/output error and you have specified IOSTAT on
the input/output statement in error, the IOSTAT variable is assigned a value
according to Conditions and IOSTAT Values in the XL Fortran Enterprise Edition for
AIX Language Reference.
If you have installed the XL Fortran run-time message catalog on the system on
which the program is executing, a message number and message text are issued to
the terminal (standard error) for certain I/O errors. If you have specified IOMSG
on the input/output statement, the IOMSG variable is assigned the error message
text if an error is detected, or the content of IOMSG variable is not changed. If this
catalog is not installed on the system, only the message number appears. Some of
the settings in “Setting Run-Time Options” on page 51 allow you to turn some of
these error messages on and off.
If a program fails while writing a large data file, you may need to increase the
maximum file size limit for your user ID. You can do this through a shell
command, such as ulimit in ksh, or through the smit command.
Tracebacks and Core Dumps
If a run-time exception occurs and an appropriate exception handler is installed, a
message and a traceback listing are displayed. Depending on the handler, a core
file might be produced as well. You can then use a debugger to examine the
location of the exception.
To produce a traceback listing without ending the program, call the xl__trbk
procedure:
IF (X .GT. Y) THEN ! X > Y indicates that something is wrong.
PRINT *, ’Error - X should not be greater than Y’
CALL XL__TRBK ! Generate a traceback listing.
X = 0
! The program continues.
END IF
See “Installing an Exception Handler” on page 298 for instructions about exception
handlers and “XL Fortran Run-Time Exceptions” on page 66 for information about
the causes of run-time exceptions.
Debugging a Fortran 90 or Fortran 95 Program
XL Fortran includes a technology preview of the IBM Distributed Debugger, a
client-server debugger, which you can use to help debug your programs. The
Distributed Debugger can debug programs running on systems accessible through
a network connection as well as debug programs running on your workstation.
For instructions on using your chosen debugger, consult the online help within the
debugger or its documentation.
Always specify the -g option when compiling programs for debugging.
Related information: See “Options for Error Checking and Debugging” on page
75.
376 XL Fortran Enterprise Edition for AIX : User’s Guide