On Fri, Jul 10, 2015 at 06:20:47PM +0200, Mikael Morin wrote:
>
> I'm not completely convinced by the standard excerpts that have been
> quoted about this topic, as they don't have any explicit mention of
> allocatable variables/expressions.
I did not quote 12.3.3 about "characteristics of function results",
which mentions the allocatable attribute. But, that is not
necessarily relevant. The pieces I quoted explicitly states
"On completion of execution of the function, the value returned
is that of its function result. ... If the function result is
not a pointer, its value shall be defined by the function."
The function not only needs to allocate memory, it needs to
assign it a value. In the following, if i <= 0, the function
result is not defined.
module foo
contains
function bar(i)
integer, allocatable :: bar
integer, intent(in) :: i
if (i > 0) bar = i
end function bar
end module foo
program test
use foo
integer j
j = bar( 3); print *, j
j = bar(-3); print *, j
end if
end program test
Even if Andre developed a patch to allocate memory in
bar() for the i <= 0 case to prevent the segfault, the
function must return a value. What should that value be?
I suppose one could argue that gfortran should issue
a run-time error if it can detect the undefined function
result. But may lead to a run-time penalty.
--
Steve
