http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57096
Bug #: 57096
Summary: Polymorphic allocatable variable is not behaved as
expected
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: fg...@hotmail.com
Created attachment 29955
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29955
simple test program with Makefile
The global variable gA and gAp are allocatable and pointer of abstract derived
type A, respectively.
class(A), allocatable :: gA ! polymorphic allocatable variable
class(A), pointer :: gAp ! polymorphic pointer variable
They are allocated with the same type (A1 or A2) extends from type A and
intialized in the same way.
subroutine init(i) bind(c, name="init")
...
if(i == 1) then
allocate(A1::gA)
allocate(A1::gAp)
else
allocate(A2::gA)
allocate(A2::gAp)
end if
call gA%init()
call gAp%init()
...
then
subroutine run() bind(c, name="run")
....
print*, "gA%next():", gA%next()
print*, "gA%next():", gA%next()
print*, "gA%next():", gA%next()
print*
print*, "gAp%next():", gAp%next()
print*, "gAp%next():", gAp%next()
print*, "gAp%next():", gAp%next()
...
When they are called from a C++ program, however, they behave quitely
differently.
extern "C" {
extern void init(int i);
extern void run();
}
int main()
{
init(2);
run();
return 0;
}
The test program output is
% ./test
gA%next(): 0
gA%next(): 0
gA%next(): 0
gAp%next(): 2
gAp%next(): 4
gAp%next(): 6
where only the pointer version behaves as expected.
