[Pkg-octave-devel] Bug#427257: Bug#427257: octave2.9: Missing -ff2c compiler flag causes wrong result on amd64

[Thomas Weber]

Hi, 

Am Samstag, 2. Juni 2007 21:14 schrieb Ming Hua:
> First I must apologize for reporting a bug I can't reproduce. 

It's not necessary to reproduce it. Octave's test suite shows it in the build 
logs (this one from AMD64)

	liboctave/CMatrix.cc ................ PASS    5/6    FAIL 1

> The conclusion on upstream mailing list seems to be that Debian package
> is missing the -ff2c flag when using gfortran to compile octave and
> linking to g77-compiled BLAS/ATLAS libraries.

The main problem I have with adding "-ff2c": it just hides the real problem, 
namely the changes between g77 and gfortran. So if all packages start 
using "-ff2c", how can we trigger a transition from g77 to gfortran 
*without* -ff2c later?

From gfortran's manpage:
Caution: It is not a good idea to mix Fortran code compiled with
           "-ff2c" with code compiled with the default "-fno-f2c" calling con‐
           ventions as, calling "COMPLEX" or default "REAL" functions between
           program parts which were compiled with different calling conven‐
           tions will break at execution time.

Caution: This will break code which passes intrinsic functions of
           type default "REAL" or "COMPLEX" as actual arguments, as the
           library implementations use the -fno-f2c calling conventions.


I'll ask on debian-gcc.

	Thomas