[Bug libfortran/113897] New: Consecutive tab edits in format are not processed correctly.

[Bug libfortran/113897] New: Consecutive tab edits in format are not processed correctly.

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113897

            Bug ID: 113897
           Summary: Consecutive tab edits in format are not processed
                    correctly.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jvdelisle at gcc dot gnu.org
  Target Milestone: ---

This issue found while working on pr109358.

program tabs
  implicit none
  integer :: fd
  open(newunit=fd, file="test.txt", form="formatted")
  write(fd, "(a)") "12345678901234567890123456789"
  write(fd, "(i4, t25, t2, i4.4)") 1234, 0123
  close(fd)
end program tabs

With gfortran gcc 10.4.1 20230121 (GCC)

$ gfc10 -static -o tabs.x tabs.f90
$ ./tabs.x 
$ cat test.txt 
12345678901234567890123456789
1234                0123

It seems to me this should be:

10123

Even though it is nonsensical to do this, it probably is valid. I will check
the standards.

[Bug libfortran/113897] Consecutive tab edits in format are not processed correctly.

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113897

Jerry DeLisle <jvdelisle at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-02-13
           Assignee|unassigned at gcc dot gnu.org      |jvdelisle at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
Adding to my list, but I do not see any priority needed for it.

[Bug libfortran/113897] Consecutive tab edits in format are not processed correctly.

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113897

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |anlauf at gcc dot gnu.org

--- Comment #2 from anlauf at gcc dot gnu.org ---
(In reply to Jerry DeLisle from comment #1)
> Adding to my list, but I do not see any priority needed for it.

I've just reopened pr109358, as it is not only tabs, but also nX.

> Even though it is nonsensical to do this,

Format strings could be machine generated, like other program text.
Some of the changes (like line-length, statement length) of F2023
seem to be made to support such stuff, so let's expect the worst...

[Bug libfortran/113897] Consecutive tab and/or nX edits in format are not processed correctly.

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113897

Jerry DeLisle <jvdelisle at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |urbanjost at comcast dot net

--- Comment #3 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
*** Bug 114618 has been marked as a duplicate of this bug. ***