------- Comment #2 from kargl at gcc dot gnu dot org 2007-01-12 18:10 -------
The Fortran standard has never mandated pass-by-reference in
either subroutine or function call. A Fortran compiler can
use either pass-by-reference or pass-by-value. In fact, the
Standard does not require a Fortran processor to diagnose
that the programmer may be doing some stupid.
To understand why this is a stupid thing to do, here's the output
from -fdump-tree-original:
laptop:kargl[228] more b.f.003t.original
MAIN__ ()
{
_gfortran_set_std (70, 127, 0);
{
static int4 C.989 = 1;
sub (&C.989);
}
sub (i)
{
*i = *i + 1;
goto __return_sub;
__return_sub:;
The "static int C.989 = 1" is then transformed into this assembly:
.file "b.f"
.section .rodata
.align 4
.LC0:
.long 1
.text
.globl MAIN__
.type MAIN__, @function
MAIN__:
pushl %ebp
movl %esp, %ebp
subl $8, %esp
subl $4, %esp
pushl $0
pushl $127
pushl $70
call _gfortran_set_std
addl $16, %esp
subl $12, %esp
pushl $.LC0
call sub_
Notice you're trying to modify read-only data.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30450
