[Bug fortran/32987] New: GFortran FORMAT statement error

[Bug fortran/32987] New: GFortran FORMAT statement error

[satyaakam at yahoo dot co dot in]

GFortarn has runtime error when FORMAT has TAB char between parameters (see
testcase)

10     format ('Hello ',        'bug!')
                         ^^^

> ./a.out
At line 2 of file format_with_tab.f
Fortran runtime error: Unexpected element in format
('Hello ',      'bug!')
           ^

This bug is reproduced in 4.1.2


-- 
           Summary: GFortran FORMAT statement error
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: satyaakam at yahoo dot co dot in


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] GFortran FORMAT statement error

[satyaakam at yahoo dot co dot in]

------- Comment #1 from satyaakam at yahoo dot co dot in  2007-08-04 13:56 -------
Created an attachment (id=14021)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14021&action=view)
testcase


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] GFortran FORMAT statement error

[kargl at gcc dot gnu dot org]

------- Comment #2 from kargl at gcc dot gnu dot org  2007-08-04 15:56 -------
Fix your code.  A tab is not a legal substitution for a space
character.


-- 

kargl at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] GFortran FORMAT statement error

[kargl at gcc dot gnu dot org]

------- Comment #3 from kargl at gcc dot gnu dot org  2007-08-04 16:26 -------
Here's a patch that permits gfortran to accept your INVALID code.
Your code should be fixed, and I will activity oppose application
of this patch by others.


Index: format.c
===================================================================
--- format.c    (revision 127165)
+++ format.c    (working copy)
@@ -92,7 +92,7 @@
       fmt->format_string_len--;
       c = toupper (*fmt->format_string++);
     }
-  while (c == ' ' && !literal);
+  while ((c == ' ' || c == '\t') && !literal);

   return c;
 }


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[burnus at gcc dot gnu dot org]

------- Comment #4 from burnus at gcc dot gnu dot org  2007-08-04 16:53 -------
I just checked: ifort, sunf95, openf95, g95 and even the picky NAG f95 accept
it. None of the compilers gives a warning except of "ifort" when passing the
option "-stand 95":

fortcom: Warning: format_with_tab.f, line 3: Extension to FORTRAN-90: tab
formatting
 10     format ('Hello ',       'bug!')
------------------------^

I therefore suggest:
- Silently accept the tab in libgfortran
- Give a warning or an error with -std=f95/f2003.

Index: gcc/fortran/io.c
===================================================================
--- gcc/fortran/io.c    (revision 127204)
+++ gcc/fortran/io.c    (working copy)
@@ -183,0 +184,2 @@ next_char_not_space (void)
+      if (c == '\t' && !(gfc_option.allow_std & GFC_STD_GNU))
+       gfc_warning ("Extension: Tab character in format at %C");
Index: libgfortran/io/format.c
===================================================================
--- libgfortran/io/format.c     (revision 127204)
+++ libgfortran/io/format.c     (working copy)
@@ -95 +95 @@ next_char (format_data *fmt, int literal
-  while (c == ' ' && !literal);
+  while ((c == ' ' || c == '\t') && !literal);


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu dot
                   |                            |org
             Status|RESOLVED                    |UNCONFIRMED
           Keywords|                            |diagnostic
         Resolution|FIXED                       |
            Summary|GFortran FORMAT statement   |TAB in FORMAT: accept
                   |error                       |extension, warn with -std=f*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[sgk at troutmask dot apl dot washington dot edu]

------- Comment #5 from sgk at troutmask dot apl dot washington dot edu  2007-08-04 17:00 -------
Subject: Re:  TAB in FORMAT: accept extension, warn with -std=f*

On Sat, Aug 04, 2007 at 04:53:33PM -0000, burnus at gcc dot gnu dot org wrote:
> 
> 
> I therefore suggest:
> - Silently accept the tab in libgfortran

I disagree on this point.  gfortran has been around for a long
time now and this is the first report of the tab-in-format
runtime error.  gfortran should complain loudly that the 
code is invalid.

> - Give a warning or an error with -std=f95/f2003.

What about -std=f66, f77, or f90?  Yes, I know gfortran doesn't
have these levels, but the tab violates all fortran standards.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[burnus at gcc dot gnu dot org]

------- Comment #6 from burnus at gcc dot gnu dot org  2007-08-04 17:37 -------
> > - Silently accept the tab in libgfortran
> I disagree on this point.

Discussion -> fortran@gcc list; starts here:
http://gcc.gnu.org/ml/fortran/2007-08/msg00097.html

> > - Give a warning or an error with -std=f95/f2003.
> What about -std=f66, f77, or f90?
I meant: Give a warning for all -std=* except of -std=gnu/legacy; as gfortran
has no fIV, f66, f77, f90, f2008, F (yet?) the two statements are the same.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[patchapp at dberlin dot org]

------- Comment #7 from patchapp at dberlin dot org  2007-08-04 17:40 -------
Subject: Bug number PR32987

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/2007-08/msg00246.html


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[burnus at gcc dot gnu dot org]

------- Comment #8 from burnus at gcc dot gnu dot org  2007-08-09 22:03 -------
Subject: Bug 32987

Author: burnus
Date: Thu Aug  9 22:02:32 2007
New Revision: 127324

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=127324
Log:
2007-08-09  Tobias Burnus  <burnus@net-b.de>

        PR fortran/32987
        * io.c (format_token): Add FMT_ERROR.
        (next_char_not_space): Print error/warning when
        '\t' are used in format specifications.
        (format_lex): Propagate error.
        (check_format): Ditto.

2007-08-09  Tobias Burnus  <burnus@net-b.de>

        PR fortran/32987
        * io/format.c (next_char): Treat '\t' as ' ' in format specification.

2007-08-09  Tobias Burnus  <burnus@net-b.de>

        PR fortran/32987
        * gfortran.dg/fmt_tab_1.f90: New.
        * gfortran.dg/fmt_tab_2.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/fmt_tab_1.f90
    trunk/gcc/testsuite/gfortran.dg/fmt_tab_2.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/io.c
    trunk/gcc/testsuite/ChangeLog
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/io/format.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[burnus at gcc dot gnu dot org]

------- Comment #9 from burnus at gcc dot gnu dot org  2007-08-09 22:08 -------
FIXED for gfortran 4.3.0; gfortran now accepts the tab; it checks also at
compile time for the tab character and gives either a warning (-std=gnu/legacy)
or an error (-std=f95/f2003) if a tab has been found.


-- 

burnus at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[satyaakam at yahoo dot co dot in]

------- Comment #10 from satyaakam at yahoo dot co dot in  2007-08-10 03:27 -------
Hi ,
    Any plans to backport.

regards
Satya 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[sgk at troutmask dot apl dot washington dot edu]

------- Comment #11 from sgk at troutmask dot apl dot washington dot edu  2007-08-10 03:50 -------
Subject: Re:  TAB in FORMAT: accept extension, warn with -std=f*

On Fri, Aug 10, 2007 at 03:27:33AM -0000, satyaakam at yahoo dot co dot in
wrote:
> 
>     Any plans to backport.
> 

No. 

Please fix your BROKEN code so gfortran doesn't need to 
grow any further questionable extension.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[fago at caltech dot edu]

------- Comment #12 from fago at caltech dot edu  2007-08-30 21:52 -------
A stupid question: why cannot gfortran detect this invalid code at compile
time? I was quite surprised by a runtime error.

BTW, I was compiling some legacy code with 4.2.1 and just hit this ...


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987

[Bug fortran/32987] TAB in FORMAT: accept extension, warn with -std=f*

[sgk at troutmask dot apl dot washington dot edu]

------- Comment #13 from sgk at troutmask dot apl dot washington dot edu  2007-08-30 22:24 -------
Subject: Re:  TAB in FORMAT: accept extension, warn with -std=f*

On Thu, Aug 30, 2007 at 09:52:56PM -0000, fago at caltech dot edu wrote:
> 
> ------- Comment #12 from fago at caltech dot edu  2007-08-30 21:52 -------
> A stupid question: why cannot gfortran detect this invalid code at compile
> time? I was quite surprised by a runtime error.
> 

See comment #9 in bugzilla.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32987