[flang] DTIO SIGABRT when the input item is namelist.

[DanielCChen]

Consider the following code:

module m
   type base
      integer :: i = 999
   end type

   type, extends(base) :: child
      integer :: i1 = 999
   end type

   type(child) :: b1(2,2)
   type(child) :: b2(3,3)

end module

module m1
   use m
   interface read(formatted)
      subroutine readformatted(dtv, unit, iotype, v_list, iostat, iomsg )
         import base
         class(base), intent(inout) :: dtv
         integer,  intent(in) :: unit
         character(*), intent(in) :: iotype
         integer, intent(in)     :: v_list(:)
         integer,  intent(out) :: iostat
         character(*),  intent(inout) :: iomsg
      end subroutine
   end interface
end module

program array101a
   use m1

   integer :: stat = 0
   character(200) :: msg = ''
   namelist /nml1/ b1, b2

   open (1, file = 'array101a.1', form='formatted', access='stream' )

   read (1,NML=nml1, iostat=stat, iomsg=msg)

end program


subroutine readformatted (dtv, unit, iotype, v_list, iostat, iomsg)
   use m, only: base, child

   class(base), intent(inout) :: dtv
   integer, intent(in) :: unit
   character(*), intent(in) :: iotype
   integer, intent(in)     :: v_list(:)
   integer, intent(out) :: iostat
   character(*), intent(inout) :: iomsg

end subroutine

array101a.1 has

&NML1
 B1(1,1)= 101 102 , B1(2,1:2)= 103 104 105 106 , B2(3:1:-1,1)= 205 206 203 204 201 202 ,
 B2(1:2,2)= 207 208 209 210,
 /
 &NML2
 B3(2,2)= 999 , B3(1:2,1:2)= 301 302 303 304 ,
 /
 &NML3
 B4= 401 402 403 404 /
 /                !<- not enough data supplied
 B5(3:1:-2,1)= 501 502 503 504 ,
 B5(3:1:-2,2)= 506 507 508 509
 /

Flang failed at:

> a.out

fatal Fortran runtime error(t.f:39): DescriptorIO: bad type code (0) in descriptor
IOT/Abort trap(coredump)

[llvmbot]

@llvm/issue-subscribers-flang-runtime

Author: Daniel Chen (DanielCChen)

Consider the following code: ``` module m type base integer :: i = 999 end type

type, extends(base) :: child
integer :: i1 = 999
end type

type(child) :: b1(2,2)
type(child) :: b2(3,3)

end module

module m1
use m
interface read(formatted)
subroutine readformatted(dtv, unit, iotype, v_list, iostat, iomsg )
import base
class(base), intent(inout) :: dtv
integer, intent(in) :: unit
character(), intent(in) :: iotype
integer, intent(in) :: v_list(:)
integer, intent(out) :: iostat
character(), intent(inout) :: iomsg
end subroutine
end interface
end module

program array101a
use m1

integer :: stat = 0
character(200) :: msg = ''
namelist /nml1/ b1, b2

open (1, file = 'array101a.1', form='formatted', access='stream' )

read (1,NML=nml1, iostat=stat, iomsg=msg)

end program

subroutine readformatted (dtv, unit, iotype, v_list, iostat, iomsg)
use m, only: base, child

class(base), intent(inout) :: dtv
integer, intent(in) :: unit
character(), intent(in) :: iotype
integer, intent(in) :: v_list(:)
integer, intent(out) :: iostat
character(), intent(inout) :: iomsg

end subroutine

`array101a.1` has

&NML1
B1(1,1)= 101 102 , B1(2,1:2)= 103 104 105 106 , B2(3:1:-1,1)= 205 206 203 204 201 202 ,
B2(1:2,2)= 207 208 209 210,
/
&NML2
B3(2,2)= 999 , B3(1:2,1:2)= 301 302 303 304 ,
/
&NML3
B4= 401 402 403 404 /
/ !<- not enough data supplied
B5(3:1:-2,1)= 501 502 503 504 ,
B5(3:1:-2,2)= 506 507 508 509
/

Flang failed at:

> a.out

fatal Fortran runtime error(t.f:39): DescriptorIO: bad type code (0) in descriptor
IOT/Abort trap(coredump)

</details>

[DanielCChen]

@klausler
PR #151571 fixed the reducer in this issue. However, the full test case still fails when verifying the run result of b5 (no longer crash with runtime error).
The following is another reducer.

module m
   type base
      integer :: i = 999
   end type

   type, extends(base) :: child
      integer :: i1 = 999
   end type

   type(child), allocatable   :: b4(:,:)
   class(child), pointer      :: b5(:,:)

end module

module m1
   use m
   interface read(formatted)
      subroutine readformatted(dtv, unit, iotype, v_list, iostat, iomsg )
         import base
         class(base), intent(inout) :: dtv
         integer,  intent(in) :: unit
         character(*), intent(in) :: iotype
         integer, intent(in)     :: v_list(:)
         integer,  intent(out) :: iostat
         character(*),  intent(inout) :: iomsg
      end subroutine
   end interface
end module

program array101a
   use m1

   integer :: stat = 0
   character(200) :: msg = 'original'
   namelist /nml3/ b4, b5

   open (1, file = 'array101a.1', form='formatted', access='stream' )
   allocate(b4(2,2), b5(3,3))

   read (1,NML=nml3, iostat=stat, iomsg=msg)

   if ( ( b5(1,1)%i /= 503 ) .or. ( b5(1,1)%i1 /= 504 ) .or. &
        ( b5(3,3)%i /= 999 ) .or. ( b5(3,3)%i1 /= 999 ))            ERROR STOP 8

end program


subroutine readformatted (dtv, unit, iotype, v_list, iostat, iomsg)
   use m, only: base, child

   class(base), intent(inout) :: dtv
   integer, intent(in) :: unit
   character(*), intent(in) :: iotype
   integer, intent(in)     :: v_list(:)
   integer, intent(out) :: iostat
   character(*), intent(inout) :: iomsg

   if ( iotype /= "NAMELIST" ) ERROR STOP 9
   if ( size(v_list, 1) /= 0 ) ERROR STOP 10
   select type (dtv)
      type is (base)
         read (unit, *, iostat=iostat )      dtv%i
      type is (child)
         read (unit, *, iostat=iostat )      dtv%i, dtv%i1
   end select
   iomsg = 'dtioread'

end subroutine

[klausler]

Your input file has two / characters after the input to B4 that terminate the namelist input before it reaches the input into B5.

[DanielCChen]

Right, that is part of the testing. It seems gfortran also supports it.

[klausler]

Supports what, exactly? What is the extension here?

[klausler]

A slash encountered as a value separator during the execution of a namelist input statement causes termination
of execution of that input statement after transference of the previous value. If there are additional items in the
namelist group object being transferred, the effect is as if null values had been supplied for them.
4 Successive namelist records are read by namelist input until a slash is encountered; the remainder of the record
is ignored.
5 A namelist comment may appear after any value separator except a slash (which terminates namelist input). A
namelist comment is also permitted to start in the first nonblank position of an input record except within a
character literal constant.

If the extension is to ignore a pair of / characters (on the same line or on adjacent lines?), then it probably falls outside the scope of extensions for flang-new, since it would be ambiguous for conceivable conforming programs that want to perform non-list-directed input after the namelist and expect to encounter a '/' character.

[DanielCChen]

Yeah. That sounds fair. Let me investigate a bit more on that exactly the reason is for the extension.