[Bug libfortran/27784] New: Comparison of strings with char(0)

[Bug libfortran/27784] New: Comparison of strings with char(0)

[tkoenig at gcc dot gnu dot org]

$ cat string_null_compare_1.f
      program main
      character*3 str1, str2
      call setval(str1, str2)
      if (str1 == str2) print *,'Should be unqual'
      end

      subroutine setval(str1, str2)
      character*3 str1, str2
      str1 = 'a' // CHAR(0) // 'a'
      str2 = 'a' // CHAR(0) // 'c'
      end
$ gfortran string_null_compare_1.f
$ ./a.out
 Should be unqual
$ g77 string_null_compare_1.f
$ ./a.out
$


-- 
           Summary: Comparison of strings with char(0)
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tkoenig at gcc dot gnu dot org
OtherBugsDependingO 19292
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] Comparison of strings with char(0)

[tkoenig at gcc dot gnu dot org]

-- 

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|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-05-28 14:04:28
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] Comparison of strings with char(0)

[fxcoudert at gcc dot gnu dot org]

------- Comment #1 from fxcoudert at gcc dot gnu dot org  2006-05-28 15:49 -------
What about simply doing:

Index: intrinsics/string_intrinsics.c
===================================================================
--- intrinsics/string_intrinsics.c      (revision 113849)
+++ intrinsics/string_intrinsics.c      (working copy)
@@ -109,7 +109,7 @@
   const char *s;
   int len;

-  res = strncmp (s1, s2, (len1 < len2) ? len1 : len2);
+  res = memcmp (s1, s2, (len1 < len2) ? len1 : len2);
   if (res != 0)
     return res;


I was told that using memcmp is safe without checking it in configury, because
it is present in libiberty if not in the system.


-- 

fxcoudert at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] Comparison of strings with char(0)

[tkoenig at gcc dot gnu dot org]

------- Comment #2 from tkoenig at gcc dot gnu dot org  2006-05-28 16:05 -------
(In reply to comment #1)
> What about simply doing:
> 
> Index: intrinsics/string_intrinsics.c
> ===================================================================
> --- intrinsics/string_intrinsics.c      (revision 113849)
> +++ intrinsics/string_intrinsics.c      (working copy)
> @@ -109,7 +109,7 @@
>    const char *s;
>    int len;
> 
> -  res = strncmp (s1, s2, (len1 < len2) ? len1 : len2);
> +  res = memcmp (s1, s2, (len1 < len2) ? len1 : len2);
>    if (res != 0)
>      return res;

Yes, this works.  I actually regtested and submitted this,
but somehow E-Mail to the fortran mailing list has been
broken for me.  Mabe the E-Mail will appear a bit later.

In the meantime, this patch is approved :-)

Thomas


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] Comparison of strings with char(0)

[fxcoudert at gcc dot gnu dot org]

------- Comment #3 from fxcoudert at gcc dot gnu dot org  2006-05-28 16:28 -------
(In reply to comment #2)
> In the meantime, this patch is approved :-)

No, your patch is approved! Please go ahead and commit :)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] [4.1 only] Comparison of strings with char(0)

[fxcoudert at gcc dot gnu dot org]

------- Comment #4 from fxcoudert at gcc dot gnu dot org  2006-06-19 22:16 -------
This was fixed on mainline by:

r114175 | tkoenig | 2006-05-28 22:25:15 +0200 (Sun, 28 May 2006) | 11 lines

2006-05-28  Thomas Koenig  <Thomas.Koenig@online.de>

        * intrinsics/string_intrinsics.c (compare_string):
        Use memcmp instead of strncmp to avoid tripping over
        CHAR(0) in a string.

2006-05-28  Thomas Koenig  <Thomas.Koenig@online.de>

        * gfortran.dg/string_null_compare_1.f:  New test case.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch
      Known to fail|                            |4.1.2
      Known to work|                            |4.2.0
            Summary|Comparison of strings with  |[4.1 only] Comparison of
                   |char(0)                     |strings with char(0)
   Target Milestone|---                         |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] [4.1 only] Comparison of strings with char(0)

[fxcoudert at gcc dot gnu dot org]

------- Comment #5 from fxcoudert at gcc dot gnu dot org  2006-06-20 06:04 -------
Subject: Bug 27784

Author: fxcoudert
Date: Tue Jun 20 06:04:14 2006
New Revision: 114803

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=114803
Log:
2006-06-20  Francois-Xavier Coudert  <coudert@clipper.ens.fr>

        PR fortran/27958
        * trans-expr.c (gfc_conv_substring): If the substring start is
        greater than its end, the length of the substring is zero, and
        not negative.
        (gfc_trans_string_copy): Don't generate a call to
        _gfortran_copy_string when destination length is zero.

2006-06-20  Francois-Xavier Coudert  <coudert@clipper.ens.fr>

        PR libfortran/27895
        * resolve.c (compute_last_value_for_triplet): New function.
        (check_dimension): Correctly handle zero-sized array sections.
        Add checking on last element of array sections.

2006-06-20  Francois-Xavier Coudert  <coudert@clipper.ens.fr>

        * trans.c (gfc_msg_bounds, gfc_msg_fault, gfc_msg_wrong_return):
        Add strings for common runtime error messages.
        (gfc_trans_runtime_check): Add a locus argument, use a string
        and not a string tree for the message.
        * trans.h (gfc_trans_runtime_check): Change prototype accordingly.
        (gfc_msg_bounds, gfc_msg_fault, gfc_msg_wrong_return): Add proto.
        * trans-const.c (gfc_strconst_bounds, gfc_strconst_fault,
        gfc_strconst_wrong_return, gfc_strconst_current_filename): Remove.
        (gfc_init_constants): Likewise.
        * trans-const.h: Likewise.
        * trans-decl.c (gfc_build_builtin_function_decls): Call to
        _gfortran_runtime_error has only one argument, the message string.
        * trans-array.h (gfc_conv_array_ref): Add a symbol argument and a
        locus.
        * trans-array.c (gfc_trans_array_bound_check): Build precise
        error messages.
        (gfc_conv_array_ref): Use the new symbol argument and the locus
        to build more precise error messages.
        (gfc_conv_ss_startstride): More precise error messages.
        * trans-expr.c (gfc_conv_variable): Give symbol reference and
        locus to gfc_conv_array_ref.
        (gfc_conv_function_call): Use the new prototype for
        gfc_trans_runtime_check.
        * trans-stmt.c (gfc_trans_goto): Build more precise error message.
        * trans-io.c (set_string): Likewise.
        * trans-intrinsic.c (gfc_conv_intrinsic_bound): Use new prototype
        for gfc_trans_runtime_check.

2006-06-20  Thomas Koenig  <Thomas.Koenig@online.de>

        PR fortran/27715
        * arith.c:  Cast the characters from the strings to unsigned
        char to avoid values less than 0 for extended ASCII.

2006-06-20  Thomas Koenig  <Thomas.Koenig@online.de>

        PR libfortran/27784
        * intrinsics/string_intrinsics.c (compare_string):
        Use memcmp instead of strncmp to avoid tripping over
        CHAR(0) in a string.

2006-06-20  Francois-Xavier Coudert  <coudert@clipper.ens.fr>

        PR fortran/27958
        * gcc/testsuite/gfortran.dg/substr_2.f: New test.

2006-06-20  Francois-Xavier Coudert  <coudert@clipper.ens.fr>

        PR libfortran/27895
        * gfortran.dg/bounds_check_3.f90: New test.

2006-06-20  Thomas Koenig  <Thomas.Koenig@online.de>

        PR fortran/27715
        * gfortran.dg/extended_char_comparison_1.f:  New test.

2006-06-20  Thomas Koenig  <Thomas.Koenig@online.de>

        PR fortran/27784
        * gfortran.dg/string_null_compare_1.f:  New test case.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/bounds_check_3.f90
      - copied unchanged from r114414,
trunk/gcc/testsuite/gfortran.dg/bounds_check_3.f90
   
branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/extended_char_comparison_1.f
      - copied unchanged from r114317,
trunk/gcc/testsuite/gfortran.dg/extended_char_comparison_1.f
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/string_null_compare_1.f
      - copied unchanged from r114175,
trunk/gcc/testsuite/gfortran.dg/string_null_compare_1.f
    branches/gcc-4_1-branch/gcc/testsuite/gfortran.dg/substr_2.f
      - copied unchanged from r114496,
trunk/gcc/testsuite/gfortran.dg/substr_2.f
Modified:
    branches/gcc-4_1-branch/gcc/fortran/ChangeLog
    branches/gcc-4_1-branch/gcc/fortran/arith.c
    branches/gcc-4_1-branch/gcc/fortran/resolve.c
    branches/gcc-4_1-branch/gcc/fortran/trans-array.c
    branches/gcc-4_1-branch/gcc/fortran/trans-array.h
    branches/gcc-4_1-branch/gcc/fortran/trans-const.c
    branches/gcc-4_1-branch/gcc/fortran/trans-const.h
    branches/gcc-4_1-branch/gcc/fortran/trans-decl.c
    branches/gcc-4_1-branch/gcc/fortran/trans-expr.c
    branches/gcc-4_1-branch/gcc/fortran/trans-intrinsic.c
    branches/gcc-4_1-branch/gcc/fortran/trans-io.c
    branches/gcc-4_1-branch/gcc/fortran/trans-stmt.c
    branches/gcc-4_1-branch/gcc/fortran/trans.c
    branches/gcc-4_1-branch/gcc/fortran/trans.h
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_1-branch/libgfortran/ChangeLog
    branches/gcc-4_1-branch/libgfortran/intrinsics/string_intrinsics.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784

[Bug libfortran/27784] Comparison of strings with char(0)

[fxcoudert at gcc dot gnu dot org]

------- Comment #6 from fxcoudert at gcc dot gnu dot org  2006-06-20 06:13 -------
Fixed.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to fail|4.1.2                       |
      Known to work|4.2.0                       |4.2.0 4.1.2
         Resolution|                            |FIXED
            Summary|[4.1 only] Comparison of    |Comparison of strings with
                   |strings with char(0)        |char(0)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27784