GNU Fortran has various special options that are used for debugging either your program or the GNU Fortran compiler.
Output the internal parse tree after translating the source program into internal representation. Only really useful for debugging the GNU Fortran compiler itself.
Output the parse tree after front-end optimization. Only really useful for debugging the GNU Fortran compiler itself.
Output the internal parse tree after translating the source program
into internal representation. Only really useful for debugging the
GNU Fortran compiler itself. This option is deprecated; use
Specify a list of floating point exception traps to enable. On most
systems, if a floating point exception occurs and the trap for that
exception is enabled, a SIGFPE signal will be sent and the program
being aborted, producing a core file useful for debugging. list
is a (possibly empty) comma-separated list of the following
exceptions: ‘invalid’ (invalid floating point operation, such as
SQRT(-1.0)), ‘zero’ (division by zero), ‘overflow’
(overflow in a floating point operation), ‘underflow’ (underflow
in a floating point operation), ‘inexact’ (loss of precision
during operation), and ‘denormal’ (operation performed on a
denormal value). The first five exceptions correspond to the five
IEEE 754 exceptions, whereas the last one (‘denormal’) is not
part of the IEEE 754 standard but is available on some common
architectures such as x86.
The first three exceptions (‘invalid’, ‘zero’, and ‘overflow’) often indicate serious errors, and unless the program has provisions for dealing with these exceptions, enabling traps for these three exceptions is probably a good idea.
Many, if not most, floating point operations incur loss of precision
due to rounding, and hence the
ffpe-trap=inexact is likely to
be uninteresting in practice.
By default no exception traps are enabled.
Specify a list of floating-point exceptions, whose flag status is printed
ERROR_UNIT when invoking
list can be either ‘none’, ‘all’ or a comma-separated list
of the following exceptions: ‘invalid’, ‘zero’, ‘overflow’,
‘underflow’, ‘inexact’ and ‘denormal’. (See
-ffpe-trap for a description of the exceptions.)
By default, a summary for all exceptions but ‘inexact’ is shown.
When a serious runtime error is encountered or a deadly signal is
emitted (segmentation fault, illegal instruction, bus error,
floating-point exception, and the other POSIX signals that have the
action ‘core’), the Fortran runtime library tries to output a
backtrace of the error.
-fno-backtrace disables the backtrace
generation. This option only has influence for compilation of the
Fortran main program.
See Options for Debugging Your Program or GCC in Using the GNU Compiler Collection (GCC), for more information on debugging options.