linking files compiled with older gfortran

[Tobias Burnus]

kamaraju kusumanchi wrote:
>> Note of warning: GCC 4.5 is a developer release and there are plans to
>> restructure the array descriptor (dope vector) during the 4.5 cycle
> Thanks for the comprehensive explanation. I appreciate it. I hope
> gfortran becomes stable enough soon.
>   
Well, to a certain extent it will never happen. It is simply impossible
to envision what a new Fortran standard will bring and what is needed to
accommodate for it. The current array descriptor was created several
years ago - back then no one knew at that point which features Fortran
2008 will contain and no one has thought about how to implement them.
With commercial compilers, ABI breakages are also not rare.

If your library does not use any I/O and does not use array intrinsic
procedures, which are in the library, the ABI changes would even go
unnoticed. (Except that the library version number will be bumped.)

It is clear that any ABI breakage causes inconveniences, especially if
binary-only software is involved. Thus the goal is to keep the ABI as
long as possible and implement everything such that new features can be
added without ABI changes, but sometimes the burden of keeping the old
ABI (either by not changing anything or by having the old ABI
additionally) is simply too large.

Tobias