| Issue |
136522
|
| Summary |
[Flang] Incorrect execution result of using polymorphic variable in select type construct
|
| Labels |
flang
|
| Assignees |
|
| Reporter |
ohno-fj
|
```
Version of flang : 21.0.0(ebba554a3211b0b98d3ae33ba70f9d6ceaab6ad4)/AArch64
```
In the attached program, `variable (p)` is the return value of `function (ufun)`.
It is `a polymorphic variable` that can be of either `derived type (obj3)` or `integer type (obj)`, but it looks like the wrong behavior in `select type construct`.
`type is (integer) ` in `select type construct` is not executed.
The above program is sngg457k_22.f90.
The result is correct if the return value of `function (ufun)` is specified directly:
- Before modification
```
p=ufun(n)
select type(b=>p)
```
- After modification
```
select type(b=>ufun(n))
```
The above program is sngg457k_23.f90.
The following are the test program, Flang, Gfortran and ifx compilation/execution result.
sngg457k_22.f90:
```fortran
program main
type ty
integer :: ii
end type ty
type ,extends(ty) :: ty1
integer :: jj
end type ty1
type(ty1),target:: obj3
integer,target:: obj
class(*),allocatable::p
do n=0,1
print*,"n=",n
p=ufun(n)
select type(b=>p)
type is (ty1)
write(6,*) "b%ii = ", b%ii, " b%jj = ", b%jj
type is (integer)
write(6,*) "obj = ", obj
end select
end do
print*,"pass"
contains
function ufun(n)
class(*),pointer :: ufun
obj3%ii=1
obj3%jj=10
obj=100
select case(n)
case(0)
ufun=>obj3
case(1)
ufun=>obj
end select
end function ufun
end program main
```
```
$ flang sngg457k_22.f90; ./a.out
n= 0
b%ii = 1 b%jj = 10
n= 1
b%ii = 100 b%jj = 0
pass
$
```
```
$ gfortran sngg457k_22.f90; ./a.out
n= 0
b%ii = 1 b%jj = 10
n= 1
obj = 100
pass
$
```
```
$ ifx sngg457k_22.f90; ./a.out
n= 0
b%ii = 1 b%jj = 10
n= 1
obj = 100
pass
$
```
sngg457k_23.f90:
```fortran
program main
type ty
integer :: ii
end type ty
type ,extends(ty) :: ty1
integer :: jj
end type ty1
type(ty1),target:: obj3
integer,target:: obj
class(*),allocatable::p
do n=0,1
print*,"n=",n
! p=ufun(n)
! select type(b=>p)
select type(b=>ufun(n))
type is (ty1)
write(6,*) "b%ii = ", b%ii, " b%jj = ", b%jj
type is (integer)
write(6,*) "obj = ", obj
end select
end do
print*,"pass"
contains
function ufun(n)
class(*),pointer :: ufun
obj3%ii=1
obj3%jj=10
obj=100
select case(n)
case(0)
ufun=>obj3
case(1)
ufun=>obj
end select
end function ufun
end program main
```
```
$ flang sngg457k_23.f90; ./a.out
n= 0
b%ii = 1 b%jj = 10
n= 1
obj = 100
pass
$
```
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