Table of Contents
Previous: -f77
Option: f90
-f90=list
This setting provides detailed control
over the warnings about supported extensions to the Fortran 77 Standard
that were not adopted as part of the Fortran 90 Standard. Note that ftnchek
does not support the full Fortran 90 language. However, it does support
some common extensions to Fortran 77 that were prevalent before Fortran
90 was defined. Some of these extensions became part of the Fortran 90
Standard, but others did not. The -f90 setting warns only about the latter.
That is, this flag covers things that are neither legal Fortran 77 nor
legal Fortran 90. Therefore, the warnings controlled by this flag are
basically a subset of the warnings controlled by -f77 . The are a few case,
described below, where the circumstances in which the warning is given
are slightly different for the two flags.
The list consists of keywords
separated by commas or colons. There are three special keywords: all to
turn on all the warnings about nonstandard extensions, none to turn them
all off, and help to print the list of all the keywords with a brief
explanation of each. If list is omitted, -f90 is equivalent to -f90=all
, and -nof90 is equivalent to -f90=none .
The following keywords have identical
meanings for -f90 as for -f77 . The reader is referred to the explanations
under -f77 .
accept-type | double-complex | param-noparen |
backslash
| format-dollarsign | pointer |
byte | format-edit-descr | quad-constant
|
cpp | function-noparen | type-size |
d-comment | name-dollarsign | variable-format
|
dec-tab | param-implicit-type | vms-io |
The keywords which differ somewhat
from the corresponding -f77 keywords are as follows.
- intrinsic:
- This is
the same as for -f77 except for the intrinsic functions defined in MIL-STD
1753, which are all included in Fortran 90, and so are not warned about.
(See -intrinsic for a list.)
- long-line:
- Although the Fortran 90 Standard
allows lines longer than 72 characters in free source form, the restriction
still applies to fixed source form, which is the only form accepted by
ftnchek .
- mixed-expr:
- This is the same as for -f77 except for expressions
mixing extended precision real with complex data types, which are permitted
in Fortran 90.
- statement-order:
- This is similar to the corresponding -f77
warning, but applies the somewhat looser restrictions on statement order
of the Fortran 90 Standard. In particular, Fortran 90 allows DATA statements
and statement-function definitions to be intermixed with specification
statements.
- typeless-constant:
- In Fortran 90, binary, octal, and hexadecimal
constants of the form B'ddd' , O'ddd' , and Z'ddd' , respectively, are permitted.
Here 'ddd' represents a string of digits. ftnchek recognizes these forms,
as well as a variant of the form X'ddd' for a hexadecimal constant, and
other variants in which the base indicator B , O , Z , or X follows the
digit string. These variants were not adopted in Fortran 90, so only they
are warned about when this flag is turned on.
See also: -f77 , -f95 , -portability
, -pretty , -wordsize .
Next: -f95