[Bug libfortran/34974] New: zero bytes when reverse-tabbing long records (regression vs. g77)

[Bug libfortran/34974] New: zero bytes when reverse-tabbing long records (regression vs. g77)

[tkoenig at gcc dot gnu dot org]

$ cat tab.f
       program main
       write (*,'(t1000000,a,t1,a)') 'b', 'a'
       end
$ gfortran tab.f
$ ./a.out > foo.dat
$ od -a -N32 foo.dat
0000000   a nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul
0000020 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul
0000040


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           Summary: zero bytes when reverse-tabbing long records (regression
                    vs. g77)
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[tkoenig at gcc dot gnu dot org]

------- Comment #1 from tkoenig at gcc dot gnu dot org  2008-01-25 19:35 -------
Actually, it's "null bytes" :-)

This is related to PR 34887.

The problem here is that we tab further than our buffer size,
so we write out garbage.

Ceterum censeo stream I/O esse delendam :-)


-- 

tkoenig at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jvdelisle at gcc dot gnu dot
                   |                            |org
            Summary|zero bytes when reverse-    |null bytes when reverse-
                   |tabbing long records        |tabbing long records
                   |(regression vs. g77)        |(regression vs. g77)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #2 from jvdelisle at gcc dot gnu dot org  2008-01-26 16:22 -------
The problem first occurs at the 8192 boundary at which point we do not write
"b"

       program main
       write (10,'(t8193,a,t1,a)') 'b', 'a'
       end


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #3 from jvdelisle at gcc dot gnu dot org  2008-01-26 16:23 -------
Confirming


-- 

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         |2008-01-26 16:23:08
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[tkoenig at gcc dot gnu dot org]

------- Comment #4 from tkoenig at gcc dot gnu dot org  2008-01-26 19:43 -------
This one is tricky.

The problem occurs because of buffering.  When tabbing to
8193 in Jerry's example, we come to the end of the
buffer and flush it.

When the record is longer than the buffer length, we'll
need to extend the buffer.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #5 from jvdelisle at gcc dot gnu dot org  2008-02-13 05:48 -------
Thomas, I am going to work on this a bit.  Let me know if you have already done
so.


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jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jvdelisle at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-01-26 16:23:08         |2008-02-13 05:48:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #6 from jvdelisle at gcc dot gnu dot org  2008-02-14 06:00 -------
Created an attachment (id=15147)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15147&action=view)
Tentative patch

This patch fixes the test case when writing to an actual file, but not to
stdio.  Stdout is not seekable so this won't work for that case.  We will have
to do some more work on how we handle buffering of pre-connected units to do
better than this, and I don't think its worth the effort.  (Tabbing in formats
is a heck of a way to seek.  :)  Regression testing this now.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #7 from jvdelisle at gcc dot gnu dot org  2008-02-14 06:07 -------
Patch in comment #6 has a regression.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #8 from jvdelisle at gcc dot gnu dot org  2008-02-15 04:18 -------
Created an attachment (id=15154)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15154&action=view)
Revised patch

This patch regression tests OK.  Same issues with stdio.  Will commit for 4.4.


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #15147|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #9 from jvdelisle at gcc dot gnu dot org  2008-02-21 02:27 -------
Subject: Bug 34974

Author: jvdelisle
Date: Thu Feb 21 02:27:07 2008
New Revision: 132512

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=132512
Log:
2008-02-20  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR libfortran/35132
        * io/transfer.c (next_record_w): Truncate after the last record for
        STREAM I/O.

        PR libfortran/34954
        * io/transfer.c (data_transfer_init): Initialize dtp->rec if writing.

        PR libfortran/34974
        * io/transfer.c (formatted_transfer_scalar): Flush the buffer if skips
        is less than zero. (next_record_w): Use sseek to position the file to
        the max position reached.

Modified:
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/io/transfer.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #10 from jvdelisle at gcc dot gnu dot org  2008-02-21 02:34 -------
Subject: Bug 34974

Author: jvdelisle
Date: Thu Feb 21 02:33:17 2008
New Revision: 132513

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=132513
Log:
2008-02-20  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR libfortran/34974
        * gfortran.dg/fmt_t_7.f: New test.

        PR libfortran/35132
        * gfortran.dg/streamio_15.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/fmt_t_7.f
    trunk/gcc/testsuite/gfortran.dg/streamio_15.f90
Modified:
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #11 from jvdelisle at gcc dot gnu dot org  2008-02-21 02:44 -------
Fixed on trunk, Committed as obvious.  Original test case now gives:

$ od -a test.dat 
0000000   a  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp
0000020  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp
*
3641060  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp  sp   b
3641100  nl


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #12 from jvdelisle at gcc dot gnu dot org  2008-05-06 04:01 -------
Reverted patch which caused pr36131. Reopening this one.


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #13 from jvdelisle at gcc dot gnu dot org  2008-05-06 04:35 -------
Janne, see discussion in comment #6


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jb at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #14 from jvdelisle at gcc dot gnu dot org  2008-05-07 02:29 -------
Subject: Bug 34974

Author: jvdelisle
Date: Wed May  7 02:28:45 2008
New Revision: 135017

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=135017
Log:
2008-05-06  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

        PR libfortran/34974
        gfortran.dg/fmt_t_7.f: XFAIL this until we get issue resolved.

Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/fmt_t_7.f


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jb at gcc dot gnu dot org]

------- Comment #15 from jb at gcc dot gnu dot org  2008-05-15 18:33 -------
Subject: Bug 34974

Author: jb
Date: Thu May 15 18:30:29 2008
New Revision: 135388

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=135388
Log:
Remove XFAIL from gfortran.dg/fmt_t_7.f

2008-05-15  Janne Blomqvist  <jb@gcc.gnu.org>

        PR libfortran/34974
        * gfortran.dg/fmt_t_7.f: Remove XFAIL, patch for PR 25561/Part 1 fixes
        this.

Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/fmt_t_7.f


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jb at gcc dot gnu dot org]

------- Comment #16 from jb at gcc dot gnu dot org  2008-05-15 18:35 -------
Closing as fixed, see commit msg above.


-- 

jb at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974

[Bug libfortran/34974] null bytes when reverse-tabbing long records (regression vs. g77)

[jvdelisle at gcc dot gnu dot org]

------- Comment #17 from jvdelisle at gcc dot gnu dot org  2008-05-16 03:12 -------
The test case needs { target fd_truncate }  I will fix it.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34974