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The following options control the details of the Fortran dialect accepted by the compiler:
-ffree-form
-ffixed-form
-fall-intrinsics
EXTERNAL
.
-fd-lines-as-code
-fd-lines-as-comments
d
or D
in fixed form sources. If the -fd-lines-as-code option is
given they are treated as if the first column contained a blank. If the
-fd-lines-as-comments option is given, they are treated as
comment lines.
-fdefault-double-8
DOUBLE PRECISION
type to an 8 byte wide type. If
-fdefault-real-8 is given, DOUBLE PRECISION
would
instead be promoted to 16 bytes if possible, and -fdefault-double-8
can be used to prevent this. The kind of real constants like 1.d0
will
not be changed by -fdefault-real-8 though, so also
-fdefault-double-8 does not affect it.
-fdefault-integer-8
42
.
-fdefault-real-8
1.0
, and does promote
the default width of DOUBLE PRECISION
to 16 bytes if possible, unless
-fdefault-double-8
is given, too.
-fdollar-ok
IMPLICIT
statements is also rejected.
-fbackslash
\a
, \b
, \f
, \n
,
\r
, \t
, \v
, \\
, and \0
to the ASCII
characters alert, backspace, form feed, newline, carriage return,
horizontal tab, vertical tab, backslash, and NUL, respectively.
Additionally, \x
nn, \u
nnnn and
\U
nnnnnnnn (where each n is a hexadecimal digit) are
translated into the Unicode characters corresponding to the specified code
points. All other combinations of a character preceded by \ are
unexpanded.
-fmodule-private
PRIVATE
.
Use-associated entities will not be accessible unless they are explicitly
declared as PUBLIC
.
-ffixed-line-length-
nPopular values for n include 72 (the
standard and the default), 80 (card image), and 132 (corresponding
to “extended-source” options in some popular compilers).
n may also be `none', meaning that the entire line is meaningful
and that continued character constants never have implicit spaces appended
to them to fill out the line.
-ffixed-line-length-0 means the same thing as
-ffixed-line-length-none.
-ffree-line-length-
n-fmax-identifier-length=
n-fimplicit-none
IMPLICIT
statements. This is the equivalent of adding
implicit none
to the start of every procedure.
-fcray-pointer
-fopenmp
!$omp
directives
in free form
and c$omp
, *$omp
and !$omp
directives in fixed form,
!$
conditional compilation sentinels in free form
and c$
, *$
and !$
sentinels in fixed form,
and when linking arranges for the OpenMP runtime library to be linked
in. The option -fopenmp implies -frecursive.
-fno-range-check
a = 1. / 0
.
With this option, no error will be given and a
will be assigned
the value +Infinity
. If an expression evaluates to a value
outside of the relevant range of [-HUGE()
:HUGE()
],
then the expression will be replaced by -Inf
or +Inf
as appropriate.
Similarly, DATA i/Z'FFFFFFFF'/
will result in an integer overflow
on most systems, but with -fno-range-check the value will
“wrap around” and i
will be initialized to -1 instead.
-std=
std