[Bug libfortran/31001] New: PACK crashes on zero-sized arrays

[Bug libfortran/31001] New: PACK crashes on zero-sized arrays

[anlauf at gmx dot de]

Hi,

the following legal program crashes with a segfault at runtime:

program gfcbug60
  implicit none

  integer :: i, j
  integer, allocatable :: mm(:)
  logical, allocatable :: mask(:)

  do i = 1, 0, -1
     print *, "i =", j
     allocate (mm(i), mask(i))
     mm(:) = 1
     mask(:) = (mm == 0)
     j = count (mask)
     print *, "j =", j
     print *, "mm =", mm
     print *, "mask =", mask
     ! gfortran runtime crash for i=j=0: bug in pack for 0-sized arrays!
     print *, "pack (mm, mask) =", pack (mm, mask)
     deallocate (mm, mask)
     print *
  end do
end program gfcbug60

% gfc gfcbug60.f90 && ./a.out
 i =           0
 j =           0
 mm =           1
 mask = F
 pack (mm, mask) =

 i =           0
 j =           0
 mm =
 mask =
Segmentation fault (core dumped)


-- 
           Summary: PACK crashes on zero-sized arrays
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: anlauf at gmx dot de
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] PACK crashes on zero-sized arrays

[fxcoudert at gcc dot gnu dot org]

------- Comment #1 from fxcoudert at gcc dot gnu dot org  2007-03-03 10:38 -------
Confirmed. I thought I had fixed it, though. Backtrace is

(gdb) back
#0  pack_internal (ret=0xbfab6628, array=Variable "array" is not available.
)
    at
/home/fxcoudert/gfortran_nightbuild/trunk/libgfortran/intrinsics/pack_generic.c:162
#1  0x08048c21 in MAIN__ () at pack.f90:18
#2  0x08048d78 in main (argc=Cannot access memory at address 0x4
)
    at /home/fxcoudert/gfortran_nightbuild/trunk/libgfortran/fmain.c:18

and I'll give it a look.


-- 

fxcoudert 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         |2007-03-03 10:38:13
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] PACK crashes on zero-sized arrays

[fxcoudert at gcc dot gnu dot org]

------- Comment #2 from fxcoudert at gcc dot gnu dot org  2007-03-03 14:24 -------
Patch below, currently regtesting.


Index: libgfortran/intrinsics/pack_generic.c
===================================================================
--- libgfortran/intrinsics/pack_generic.c       (revision 122504)
+++ libgfortran/intrinsics/pack_generic.c       (working copy)
@@ -93,15 +93,19 @@

   index_type count[GFC_MAX_DIMENSIONS];
   index_type extent[GFC_MAX_DIMENSIONS];
+  int zero_sized;
   index_type n;
   index_type dim;
   index_type nelem;

   dim = GFC_DESCRIPTOR_RANK (array);
+  zero_sized = 0;
   for (n = 0; n < dim; n++)
     {
       count[n] = 0;
       extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
+      if (extent[n] <= 0)
+       zero_sized = 1;
       sstride[n] = array->dim[n].stride * size;
       mstride[n] = mask->dim[n].stride;
     }
@@ -154,6 +158,8 @@
          const GFC_LOGICAL_4 *m = mptr;

          total = 0;
+         if (zero_sized)
+           m = NULL;

          while (m)
            {


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org
   GCC host triplet|i686-pc-linux-gnu           |
           Keywords|                            |patch, wrong-code
      Known to fail|                            |4.1.2 4.2.0 4.3.0
   Last reconfirmed|2007-03-03 10:38:13         |2007-03-03 14:24:04
               date|                            |
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] PACK crashes on zero-sized arrays

[fxcoudert at gcc dot gnu dot org]

------- Comment #3 from fxcoudert at gcc dot gnu dot org  2007-03-03 16:38 -------
Subject: Bug 31001

Author: fxcoudert
Date: Sat Mar  3 16:37:54 2007
New Revision: 122507

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122507
Log:
        PR libfortran/31001

        * intrinsics/pack_generic.c (pack_internal): Add special checks
        for zero-sized arrays.

        * gfortran.dg/zero_sized_3.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/zero_sized_3.f90
Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/intrinsics/pack_generic.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] [4.1/4.2 only] PACK crashes on zero-sized arrays

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |fxcoudert at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
      Known to fail|4.1.2 4.2.0 4.3.0           |4.1.2 4.2.0
      Known to work|                            |4.3.0
   Last reconfirmed|2007-03-03 14:24:04         |2007-03-04 07:20:24
               date|                            |
            Summary|PACK crashes on zero-sized  |[4.1/4.2 only] PACK crashes
                   |arrays                      |on zero-sized arrays


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] [4.1/4.2 only] PACK crashes on zero-sized arrays

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] [4.1/4.2 only] PACK crashes on zero-sized arrays

[fxcoudert at gcc dot gnu dot org]

------- Comment #4 from fxcoudert at gcc dot gnu dot org  2007-03-08 12:35 -------
Subject: Bug 31001

Author: fxcoudert
Date: Thu Mar  8 12:34:59 2007
New Revision: 122697

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122697
Log:
        PR target/30406
        * config/rs6000/rs6000.c (rs6000_function_value): Look at bit size
        instead of precision.
        * gfortran.dg/logical_3.f90: New test.

        PR libfortran/31001
        * intrinsics/pack_generic.c (pack_internal): Add special checks
        for zero-sized arrays.
        * gfortran.dg/zero_sized_3.f90: New test.

Added:
    branches/gcc-4_2-branch/gcc/testsuite/gfortran.dg/logical_3.f90
      - copied unchanged from r122523,
trunk/gcc/testsuite/gfortran.dg/logical_3.f90
    branches/gcc-4_2-branch/gcc/testsuite/gfortran.dg/zero_sized_3.f90
      - copied unchanged from r122507,
trunk/gcc/testsuite/gfortran.dg/zero_sized_3.f90
Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/config/rs6000/rs6000.c
    branches/gcc-4_2-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_2-branch/libgfortran/ChangeLog
    branches/gcc-4_2-branch/libgfortran/intrinsics/pack_generic.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001

[Bug libfortran/31001] [4.1 only] PACK crashes on zero-sized arrays

[fxcoudert at gcc dot gnu dot org]

------- Comment #5 from fxcoudert at gcc dot gnu dot org  2007-03-14 10:49 -------
Fixed on 4.2 and 4.3.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to fail|4.1.2 4.2.0                 |4.1.2
      Known to work|4.3.0                       |4.3.0 4.2.0
         Resolution|                            |FIXED
            Summary|[4.1/4.2 only] PACK crashes |[4.1 only] PACK crashes on
                   |on zero-sized arrays        |zero-sized arrays


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31001