[Bug fortran/95718] New: Wrong pointer associated status without initialization

[Bug fortran/95718] New: Wrong pointer associated status without initialization

[peng.wang@compiler-dev.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95718

            Bug ID: 95718
           Summary: Wrong pointer associated status without initialization
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: peng.wang@compiler-dev.com
  Target Milestone: ---

consider the code below:

****
program test
integer,pointer::ptr
integer,pointer::ptr1
integer,pointer::ptr2
integer,pointer::ptr3
integer,pointer::ptr4

print*,associated(ptr),'associated(ptr)'
print*,associated(ptr1),'associated(ptr1)'
print*,associated(ptr2),'associated(ptr2)'
print*,associated(ptr3),'associated(ptr3)'
print*,associated(ptr4),'associated(ptr4)'
end program test
****

#gfortran -std=f2008 test.f90 ; ./a.out
 T associated(ptr)
 F associated(ptr1)
 T associated(ptr2)
 F associated(ptr3)
 T associated(ptr4)

the associated status of the pointers is uncertain after the execution above.

according to F2008 draft 16.5.2.7, the associated status of the pointer should
be F in the case above.

this is the options given when GCC was configured:
# gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/gcc/libexec/gcc/x86_64-pc-linux-gnu/10.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix=/usr/local/gcc -enable-checking=release
-enable-languages=c,fortran -disable-bootstrap -disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.1.0 (GCC)

[Bug fortran/95718] [8/9/10/11 Regression] Wrong pointer associated status without initialization

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95718

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |10.1.0, 11.0, 6.5.0, 7.4.0,
                   |                            |8.3.0, 9.2.0
           Priority|P3                          |P4
     Ever confirmed|0                           |1
           Keywords|                            |wrong-code
   Target Milestone|---                         |8.4
   Last reconfirmed|                            |2020-06-17
             Status|UNCONFIRMED                 |NEW
            Summary|Wrong pointer associated    |[8/9/10/11 Regression]
                   |status without              |Wrong pointer associated
                   |initialization              |status without
                   |                            |initialization
      Known to work|                            |5.5.0

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
GCC5.5.0 gives

 F associated(ptr)
 F associated(ptr1)
 F associated(ptr2)
 F associated(ptr3)
 F associated(ptr4)

[Bug fortran/95718] [8/9/10/11 Regression] Wrong pointer associated status without initialization

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95718

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
The change occurred between revisions r226476 (2015-08-02, OK) and r227252
(2015-08-27, wrong). No idea about how this translates to git!-(

[Bug fortran/95718] [8/9/10/11 Regression] Wrong pointer associated status without initialization

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95718

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |INVALID
                 CC|                            |kargl at gcc dot gnu.org

--- Comment #3 from kargl at gcc dot gnu.org ---
   16.5.2.2 Pointer association status

   A pointer may have a pointer association status of associated,
   disassociated, or undefined.  Its association status may change
   during execution of a program.  Unless a pointer is initialized
   (explicitly or by default), it has an initial association status
   of undefined.  A pointer may be initialized to have an association
   status of disassociated or associated.

   13.7.16 ASSOCIATED (POINTER [, TARGET])

   POINTER shall be a pointer.  It may be of any type or may be a
      procedure pointer.  Its pointer association status shall not
      be undefined.

Your program is invalid.

[Bug fortran/95718] [8/9/10/11 Regression] Wrong pointer associated status without initialization

[peng.wang@compiler-dev.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95718

--- Comment #4 from PengWang <peng.wang@compiler-dev.com> ---
(In reply to kargl from comment #3)
>    16.5.2.2 Pointer association status
> 
>    A pointer may have a pointer association status of associated,
>    disassociated, or undefined.  Its association status may change
>    during execution of a program.  Unless a pointer is initialized
>    (explicitly or by default), it has an initial association status
>    of undefined.  A pointer may be initialized to have an association
>    status of disassociated or associated.
> 
>    13.7.16 ASSOCIATED (POINTER [, TARGET])
> 
>    POINTER shall be a pointer.  It may be of any type or may be a
>       procedure pointer.  Its pointer association status shall not
>       be undefined.
> 
> Your program is invalid.

thank you very much! The status of undefined has confused me for a long time,
now I understand it finally, thank you~