[PATCH][fortran] Rework allocator library interface

[Tobias Burnus]

Hi all,

Richard Guenther wrote:
>> The patch is OK for trunk and 4.2.  Please wait a week or so before
>> committing to 4.2, to catch regressions that might still occur.
>>     
> Committed to trunk.  I have omitted the hunk bumping the shared library
> version as this will be not necessary if we backport to 4.2.
>   

I only want to point out that this change breaks the AMD Core Math
Library 3.6.
That library contains:

/opt/acml3.6.0/gfortran64/lib/libacml_mv.so
/opt/acml3.6.0/gfortran64/lib/libacml.so

/opt/acml3.6.0/gfortran64_mp/lib/libacml_mp.so
/opt/acml3.6.0/gfortran64_mp/lib/libacml_mv.so

The first two are the serial version, compiled with gfortran 4.1.0;
the second pair is the OpenMP version, compiled with "4.2.0 20061114".

Due to the allocate change, gfortran 4.3 programs linked to the OpenMP
version of ACML crash with:

#0  allocate_size (size=<value optimized out>, stat=0x500010) at /gcc/libgfortran/runtime/memory.c:187
187               *stat = 1;
#0  allocate_size (size=<value optimized out>, stat=0x500010) at /gcc/libgfortran/runtime/memory.c:187
#1  0x00002ba64ed18acd in zungtr8z_ () from /opt/acml3.6.0/gfortran64_mp/lib/libacml_mp.so


That their is no link-time error but a crash is rather bad :-(

Solutions:

- Simply wait - there will be surely a new ACML libraries and for
non-vendor libraries one can recompile oneself
(if one has figured out that the crash is due to the compiler update and
too old libraries.)

- Bump the library version number (we did this already recently in the
4.2-experimental version, which also broke the ACML. Upon request, one
could then get a semi-official version compiled with a newer 4.2 compiler.)

- Use other names for the new functions (= manual symbol versioning)

- Use (real) symbol versioning (unlikely to happen before 4.2.0 is released)


In any case, coredumps reported in the next weeks could be due to this
change.

Tobias