Well, it is defined as okay in my copy of the fortran 95 handbook
(complete
iso/ansi reference). I have not even looked at the 2003 stuff for fear of
backward compatibility issues, even though there is lots of stuff I would
love to see fixed. As far as what actually works, I have pointers in a
derived type in my code, and it compiles everywhere and works - everywhere
here includes an old sgi f90 compiler and the dozen or so other platforms
I
support (probably only a half dozen or so compilers currently, but I will
add gfortran/g95 prior to release). I remember agonizing over correct
initialization of the pointers to null ( =>null()). This is a f95
feature,
and I use it. Here's the thing. The standard f90 definition is broken in
not allowing this; it is plain dangerous, and fortunately every compiler I
have encountered supports the f95 extension here. Overall, if you think
about it, not having null initialization, and also not allowing pointers
in
user-defined types would be just plain dumb. One of the primary uses of
pointers is in user-defined types that make reference to other data
structures (lists, trees, etc.).
Regards - Bob
----- Original Message -----
From: "darden" <darden.gamera.niehs.nih.gov>
To: <amber-developers.scripps.edu>
Cc: <kfwong.hec.utah.edu>
Sent: Wednesday, November 09, 2005 9:18 AM
Subject: Re: amber-developers: Compile AMBER9 on SGI
>i though using pointers in place of allocatable arrays in types was ok
for
>f90? not true??
> tom d
> On Tue, 8 Nov 2005, David A. Case wrote:
>
>> On Tue, Nov 08, 2005, Wu, Xiongwu (NIH/NHLBI) [E] wrote:
>>>
>>> I am trying to compile amber9 on SGI but failed. Is this a problem of
>>> f90 of SGI? e.g. evb_vars.f produces compiling problems.
>>>
>>
>> Kim:
>>
>> This is a real problem: having allocatable arrays as a part of defined
>> types
>> is *not* standard Fortran 95 -- it is a part of Fortran 2003 that
>> happens to
>> be supported by ifort and g95. But major compilers, including SGI and
>> gfortran, do not allow these extensions.
>>
>> I am pretty reluctant to require a Fortran 2003-compliant compiler for
>> Amber 9. Is there any easy way to not have to use allocatable arrays
>> inside
>> user-defined types?
>>
>> Xiongwu:
>>
>> You could try to download the IRIX-MIPS version of g95 from
>> www.g95.org. G95 works on other platforms, so one hopes it could work
>> there as well. (I can't try this right now since we have no web
>> access).
>>
>> Otherwise, you will have to move to a non-SGI platform until we can get
>> this
>> sorted out.
>>
>> ...thanks...dac
>>
>
Received on Wed Apr 05 2006 - 23:49:50 PDT
