[Bug fortran/31618] New: backspace intrinsic is not working on an unformatted file

[Bug fortran/31618] New: backspace intrinsic is not working on an unformatted file

[Patrick dot Begou at hmg dot inpg dot fr]

Using backspace when reading an unformatted file after a read error does not
work except if it is on the first record.

The code below show the problem. This code write 3 couples of integer values in
an unformatted file called 'foo' and close it.
File is reopen for read.
Then it reads the first couple of values. It's OK.
Then it try to read 3 values and detects the error (only 2 values in the
record).
The code use backspace to go back at the begining of this record and try to
read again this record, but with only 2 values.
The values obtained are wrong.

Trying to read 3 values at the begining of the file, using backspace and
reading again only 2 values works. 

Code:

      PROGRAM gfort
      IMPLICIT NONE

      INTEGER :: x, z, count
      INTEGER :: nx, nz,LocalTimeStep 


      OPEN (21,FILE='foo',form='UNFORMATTED',err=101)
      REWIND(21)
      x=140
      z=170
      WRITE(21) x,z
      WRITE(6,*)'writing x (',x,') and z(',z,') in foo'
      x=14
      z=17
      WRITE(21) x,z
      WRITE(6,*)'writing x (',x,') and z(',z,') in foo'
      x=1400
      z=1700
      WRITE(21) x,z
      WRITE(6,*)'writing x (',x,') and z(',z,') in foo'
      CLOSE(21)


      OPEN (21,FILE='foo',form='UNFORMATTED',status='OLD',err=101)
      REWIND(21)
      WRITE(6,*)'reading first x, z in foo'
      x=-1
      z=-1
      READ(21,err=103,end=103) x,z
      WRITE(6,*)'x (',x,') and z(',z,')'

      WRITE(6,*)'reading x, z and LocalTimeStep in foo'
      nx=-1
      nz=-1
      READ(21,iostat=count) nx,nz,LocalTimeStep
      WRITE(6,*)'x (',nx,') and z(',nz,') and LocalTimeStep(',
     + LocalTimeStep,')'
         IF (count.NE.0) THEN
            WRITE(6,*)'reading again x and z in foo'
            BACKSPACE(21)
            nx=-1
            nz=-1
            READ(21,err=103,end=103) nx,nz
            LocalTimeStep=0.0
      WRITE(6,*)'x (',nx,') and z(',nz,') and LocalTimeStep(',
     + LocalTimeStep,')'
         ENDIF
      CLOSE(21)
      STOP 'OK'

101   WRITE(6,*) 'foo n''a pas ete trouve.'
      STOP 'FAILED'
103   WRITE(6,*) 'Erreur de lecture'
      CLOSE(21)
      STOP 'FAILED'
      END PROGRAM gfort



NORMAL RESULT:
 ./a.out
 writing x (         140 ) and z(         170 ) in foo
 writing x (          14 ) and z(          17 ) in foo
 writing x (        1400 ) and z(        1700 ) in foo
 reading first x, z in foo
 x (         140 ) and z(         170 )
 reading x, z and LocalTimeStep in foo
 x (          14 ) and z(          17 ) and LocalTimeStep(           0 )
 reading again x and z in foo
 x (          14 ) and z(          17 ) and LocalTimeStep(           0 )
OK

Gfortran RESULT (WRONG) :
./a.out
 writing x (         140 ) and z(         170 ) in foo
 writing x (          14 ) and z(          17 ) in foo
 writing x (        1400 ) and z(        1700 ) in foo
 reading first x, z in foo
 x (         140 ) and z(         170 )
 reading x, z and LocalTimeStep in foo
 x (          14 ) and z(          17 ) and LocalTimeStep(          17 )
 reading again x and z in foo
 x (          17 ) and z(           8 ) and LocalTimeStep(           0 )
STOP OK


-- 
           Summary: backspace intrinsic is not working on an unformatted
                    file
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Patrick dot Begou at hmg dot inpg dot fr
 GCC build triplet: gcc version 4.3.0 20070418 (experimental)
GCC target triplet: i386-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[jvdelisle at gcc dot gnu dot org]

------- Comment #1 from jvdelisle at gcc dot gnu dot org  2007-04-18 15:01 -------
hmm, I will investigate.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[jvdelisle at gcc dot gnu dot org]

------- Comment #2 from jvdelisle at gcc dot gnu dot org  2007-04-19 03:47 -------
Confirming.  g77 does not do it right either.  :)


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-19 03:47:49
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #3 from tkoenig at gcc dot gnu dot org  2007-04-19 21:35 -------
(In reply to comment #2)
> Confirming.  g77 does not do it right either.  :)

gfortran 4.1 doesn't get this right either, so at least
this isn't a regression.  Uff :-)


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tkoenig at gcc dot gnu dot
                   |                            |org
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #4 from tkoenig at gcc dot gnu dot org  2007-04-20 22:29 -------
Strictly speaking, this is not a violation of the
Fortran standard, as there are no guarantees of what happens
after an error.

Nonetheless, we should fix it.

I'm investigating.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #5 from tkoenig at gcc dot gnu dot org  2007-04-21 23:12 -------
Created an attachment (id=13402)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13402&action=view)
proposed patch

This could work.  Let's see if this passes regression.


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |tkoenig at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[jvdelisle at gcc dot gnu dot org]

------- Comment #6 from jvdelisle at gcc dot gnu dot org  2007-04-21 23:47 -------
Thats an interesting approach.  I am curious for the results.  I also like the
adjustments to errors you have made.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[patchapp at dberlin dot org]

------- Comment #7 from patchapp at dberlin dot org  2007-04-22 22:10 -------
Subject: Bug number PR 31618

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-04/msg01432.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #8 from tkoenig at gcc dot gnu dot org  2007-04-23 20:44 -------
Subject: Bug 31618

Author: tkoenig
Date: Mon Apr 23 20:43:54 2007
New Revision: 124079

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124079
Log:
2007-04-23  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/31618
        * io/transfer.c (read_block_direct):  Instead of calling us_read,
        set dtp->u.p.current_unit->current_record = 0 so that pre_position
        will read the record marker.
        (data_transfer_init):  For different error conditions, call
        generate_error, then return.

2007-04-23  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/31618
        * gfortran.dg/backspace_8.f:  New test case.


Added:
    trunk/gcc/testsuite/gfortran.dg/backspace_8.f
Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/io/transfer.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] [4.2, 4.1 only] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #9 from tkoenig at gcc dot gnu dot org  2007-04-23 20:46 -------
Fixed on trunk.

Maybe we should backport this once 4.2.1 is open.


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.2.0 4.1.2
      Known to work|                            |4.3.0
            Summary|backspace intrinsic is not  |[4.2, 4.1 only] backspace
                   |working on an unformatted   |intrinsic is not working on
                   |file                        |an unformatted file


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] [4.2, 4.1 only] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #10 from tkoenig at gcc dot gnu dot org  2007-05-20 22:09 -------
Subject: Bug 31618

Author: tkoenig
Date: Sun May 20 21:07:14 2007
New Revision: 124878

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124878
Log:
2007-05-20  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/31618
        Backport from trunk.
        * io/transfer.c (read_block_direct):  Instead of calling us_read,
        set dtp->u.p.current_unit->current_record = 0 so that pre_position
        will read the record marker.
        (data_transfer_init):  For different error conditions, call
        generate_error, then return.

2007-05-20  Thomas Koenig  <tkoenig@gcc.gnu.org>

        PR fortran/31618
        Backport from trunk.
        * gfortran.dg/backspace_8.f:  New test case.


Added:
    branches/gcc-4_2-branch/gcc/testsuite/gfortran.dg/backspace_8.f
Modified:
    branches/gcc-4_2-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_2-branch/libgfortran/ChangeLog
    branches/gcc-4_2-branch/libgfortran/io/transfer.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] [4.2, 4.1 only] backspace intrinsic is not working on an unformatted file

[tkoenig at gcc dot gnu dot org]

------- Comment #11 from tkoenig at gcc dot gnu dot org  2007-05-20 22:11 -------
Now also fixed on 4.2.1 (revision 124878).  Won't backport to 4.1.

Closing.


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|4.3.0                       |4.3.0 4.2.1
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618

[Bug fortran/31618] [4.2, 4.1 only] backspace intrinsic is not working on an unformatted file

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.2.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31618