[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[Joost.VandeVondele at pci dot uzh.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #1 from Joost VandeVondele  
2011-06-20 20:04:47 UTC ---
the difference (I think) seems to be in the present check that has become

if (data != 0B && (integer(kind=4)[0:] * restrict) data->data != 0B)

instead of the original

if (data != 0B)

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

Dominique d'Humieres  changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2011.06.20 20:16:50
 Ever Confirmed|0   |1

--- Comment #2 from Dominique d'Humieres  2011-06-20 
20:16:50 UTC ---
Revision 162456 is OK, 163718 is not.

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

Tobias Burnus  changed:

   What|Removed |Added

   Keywords||wrong-code
 CC||burnus at gcc dot gnu.org
   Target Milestone|--- |4.6.2

--- Comment #3 from Tobias Burnus  2011-06-20 
21:39:28 UTC ---
There seems to be a bug in the implementation of Fortran 2008's new feature:

"A null pointer or unallocated allocatable can be used to denote an absent
nonallocatable nonpointer optional argument."

That check has been added in Rev 163263 on 2010-08-15.

However, I am not sure that the bug is in the new code - it could also be a
RESHAPE bug (cf. PR 49324 for another reshape bug). I think gfortran's
convention is - and also TR 29113 require that the addr_expr is not NULL if the
variable is allocated - even if it is zero sized. However, I need to recheck
and maybe also other library functions have this issue.

Workaround: -std=f2003.

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #4 from Tobias Burnus  2011-06-21 
08:58:31 UTC ---
(In reply to comment #3)
> I think gfortran's convention is - and also TR 29113 requires - that the
> addr_expr is not NULL if the variable is allocated - even if it is zero sized.

The TR 29113 draft (Interop ML version) has (5.2.3 CFI_cdesc_t)
ftp://ftp.nag.co.uk/sc22wg5/N1851-N1900/N1854.pdf

"void * base addr; If the object is an unallocated allocatable or a pointer
that is disassociated, the value is NULL. If the object has zero size, the
value is not NULL but is otherwise processor-dependent. Otherwise [...]"


And trans.c has for gfc_call_malloc:
/* Call malloc to allocate size bytes of memory, with special conditions:
  + if size == 0, return a malloced area of size 1,


If one looks at RESHAPE in the library:
 
http://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libgfortran/intrinsics/reshape_generic.c;hb=HEAD
one sees:

  86   if (ret->data == NULL)
  87 {
  88   rs = 1;
  89   for (n = 0; n < rdim; n++)
  90 {
  91   rex = shape_data[n];
  93   GFC_DIMENSION_SET(ret->dim[n],0,rex - 1,rs);
  95   rs *= rex;
  96 }
  98   ret->data = internal_malloc_size ( rs * size );

Thus, if shape_data[n] == 0 -- which is here the case --, "rs" == 0 and thus
one calls malloc with zero size. POSIX states:
"If size is 0, either a null pointer or a unique pointer that can be
successfully passed to free() shall be returned."

Hence, the "rs*size" should be replaced by "MAX(1, rs*size)".

I think other intrinsics will have the same problem.

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #5 from Tobias Burnus  2011-06-21 
09:30:32 UTC ---
Actually, thinking about it: "RESHAPE(allocatable_array, shape)" is *not*
allocatable.

trans-expr.c has:
 147   if (!sym->attr.pointer && !sym->attr.allocatable
 148   && sym->as && sym->as->type == AS_ASSUMED_SHAPE
 149   && (gfc_option.allow_std & GFC_STD_F2008) != 0)

One probably needs to check the actual argument, i.e. gfc_expr_attr(actual)
with allocatable or pointer attribute - or type being C_PTR (including
C_NULL_PTR).

For the latter:
   expr->ts.type == BT_DERIVED && expr->ts.u.derived
&& expr->ts.u.derived->attr.is_iso_c
&& ??? (some check for ISOCBINDING_PTR)

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #6 from Thomas Koenig  2011-06-27 
19:02:12 UTC ---
A patch suggested by comment #4 fixes the failure.

Regression-testing.

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #7 from Thomas Koenig  2011-06-28 
18:59:06 UTC ---
Author: tkoenig
Date: Tue Jun 28 18:59:04 2011
New Revision: 175594

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175594
Log:
2011-06-28  Thomas Koenig  

PR fortran/49479
* m4/reshape.m4: If source allocation is smaller than one, set it
to one.
* intrinsics/reshape_generic.c:  Likewise.
* generated/reshape_r16.c: Regenerated.
* generated/reshape_c4.c: Regenerated.
* generated/reshape_c16.c: Regenerated.
* generated/reshape_c8.c: Regenerated.
* generated/reshape_r4.c: Regenerated.
* generated/reshape_i4.c: Regenerated.
* generated/reshape_r10.c: Regenerated.
* generated/reshape_r8.c: Regenerated.
* generated/reshape_c10.c: Regenerated.
* generated/reshape_i8.c: Regenerated.
* generated/reshape_i16.c: Regenerated.

2011-06-28  Thomas Koenig  

PR fortran/49479
* gfortran.dg/reshape_zerosize_3.f90:  New test.


Added:
trunk/gcc/testsuite/gfortran.dg/reshape_zerosize_3.f90
Modified:
trunk/gcc/testsuite/ChangeLog
trunk/libgfortran/ChangeLog
trunk/libgfortran/generated/reshape_c10.c
trunk/libgfortran/generated/reshape_c16.c
trunk/libgfortran/generated/reshape_c4.c
trunk/libgfortran/generated/reshape_c8.c
trunk/libgfortran/generated/reshape_i16.c
trunk/libgfortran/generated/reshape_i4.c
trunk/libgfortran/generated/reshape_i8.c
trunk/libgfortran/generated/reshape_r10.c
trunk/libgfortran/generated/reshape_r16.c
trunk/libgfortran/generated/reshape_r4.c
trunk/libgfortran/generated/reshape_r8.c
trunk/libgfortran/intrinsics/reshape_generic.c
trunk/libgfortran/m4/reshape.m4

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #8 from Thomas Koenig  2011-07-06 
18:50:50 UTC ---
Author: tkoenig
Date: Wed Jul  6 18:50:46 2011
New Revision: 175929

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175929
Log:
2011-07-06  Thomas Koenig  

Partial backport from trunk:
PR fortran/49479
* runtime/memory.c:  If size is zero, allocate a single byte.
* m4/eoshift1.m4:  Remove double allocation.
* m4/eoshift3.m4:  Likewise.
* generated/eoshift1_4.c:  Regenerated.
* generated/eoshift1_8.c:  Regenerated.
* generated/eoshift1_16.c:  Regenerated.
* generated/eoshift3_4.c:  Regenerated.
* generated/eoshift3_8.c:  Regenerated.
* generated/eoshift3_16.c:  Regenerated.

2011-07-06  Thomas Koenig  

PR fortran/49479
* gfortran.dg/reshape_zerosize_3.f90:  New test case.


Added:
branches/gcc-4_6-branch/gcc/testsuite/gfortran.dg/reshape_zerosize_3.f90
Modified:
branches/gcc-4_6-branch/gcc/testsuite/ChangeLog
branches/gcc-4_6-branch/libgfortran/ChangeLog
branches/gcc-4_6-branch/libgfortran/generated/eoshift1_16.c
branches/gcc-4_6-branch/libgfortran/generated/eoshift1_4.c
branches/gcc-4_6-branch/libgfortran/generated/eoshift1_8.c
branches/gcc-4_6-branch/libgfortran/generated/eoshift3_16.c
branches/gcc-4_6-branch/libgfortran/generated/eoshift3_4.c
branches/gcc-4_6-branch/libgfortran/generated/eoshift3_8.c
branches/gcc-4_6-branch/libgfortran/m4/eoshift1.m4
branches/gcc-4_6-branch/libgfortran/m4/eoshift3.m4
branches/gcc-4_6-branch/libgfortran/runtime/memory.c

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

Thomas Koenig  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution||FIXED

--- Comment #9 from Thomas Koenig  2011-07-06 
18:51:43 UTC ---
Fixed on trunk and 4.6, closing.

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #10 from Thomas Koenig  2011-09-10 
14:07:01 UTC ---
Author: tkoenig
Date: Sat Sep 10 14:06:57 2011
New Revision: 178748

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178748
Log:
2011-09-10  Thomas Koenig  

PR fortran/49479
* generated/m4/ifunction.m4:  Always call internal_malloc_size
even when there is a zero-sized return array.
* generated/generated/maxloc1_16_i16.c: Regenerated.
* generated/generated/maxloc1_16_i1.c: Regenerated.
* generated/generated/maxloc1_16_i2.c: Regenerated.
* generated/generated/maxloc1_16_i4.c: Regenerated.
* generated/generated/maxloc1_16_i8.c: Regenerated.
* generated/generated/maxloc1_16_r10.c: Regenerated.
* generated/generated/maxloc1_16_r16.c: Regenerated.
* generated/generated/maxloc1_16_r4.c: Regenerated.
* generated/generated/maxloc1_16_r8.c: Regenerated.
* generated/generated/maxloc1_4_i16.c: Regenerated.
* generated/generated/maxloc1_4_i1.c: Regenerated.
* generated/generated/maxloc1_4_i2.c: Regenerated.
* generated/generated/maxloc1_4_i4.c: Regenerated.
* generated/generated/maxloc1_4_i8.c: Regenerated.
* generated/generated/maxloc1_4_r10.c: Regenerated.
* generated/generated/maxloc1_4_r16.c: Regenerated.
* generated/generated/maxloc1_4_r4.c: Regenerated.
* generated/generated/maxloc1_4_r8.c: Regenerated.
* generated/generated/maxloc1_8_i16.c: Regenerated.
* generated/generated/maxloc1_8_i1.c: Regenerated.
* generated/generated/maxloc1_8_i2.c: Regenerated.
* generated/generated/maxloc1_8_i4.c: Regenerated.
* generated/generated/maxloc1_8_i8.c: Regenerated.
* generated/generated/maxloc1_8_r10.c: Regenerated.
* generated/generated/maxloc1_8_r16.c: Regenerated.
* generated/generated/maxloc1_8_r4.c: Regenerated.
* generated/generated/maxloc1_8_r8.c: Regenerated.
* generated/generated/maxval_i16.c: Regenerated.
* generated/generated/maxval_i1.c: Regenerated.
* generated/generated/maxval_i2.c: Regenerated.
* generated/generated/maxval_i4.c: Regenerated.
* generated/generated/maxval_i8.c: Regenerated.
* generated/generated/maxval_r10.c: Regenerated.
* generated/generated/maxval_r16.c: Regenerated.
* generated/generated/maxval_r4.c: Regenerated.
* generated/generated/maxval_r8.c: Regenerated.
* generated/generated/minloc1_16_i16.c: Regenerated.
* generated/generated/minloc1_16_i1.c: Regenerated.
* generated/generated/minloc1_16_i2.c: Regenerated.
* generated/generated/minloc1_16_i4.c: Regenerated.
* generated/generated/minloc1_16_i8.c: Regenerated.
* generated/generated/minloc1_16_r10.c: Regenerated.
* generated/generated/minloc1_16_r16.c: Regenerated.
* generated/generated/minloc1_16_r4.c: Regenerated.
* generated/generated/minloc1_16_r8.c: Regenerated.
* generated/generated/minloc1_4_i16.c: Regenerated.
* generated/generated/minloc1_4_i1.c: Regenerated.
* generated/generated/minloc1_4_i2.c: Regenerated.
* generated/generated/minloc1_4_i4.c: Regenerated.
* generated/generated/minloc1_4_i8.c: Regenerated.
* generated/generated/minloc1_4_r10.c: Regenerated.
* generated/generated/minloc1_4_r16.c: Regenerated.
* generated/generated/minloc1_4_r4.c: Regenerated.
* generated/generated/minloc1_4_r8.c: Regenerated.
* generated/generated/minloc1_8_i16.c: Regenerated.
* generated/generated/minloc1_8_i1.c: Regenerated.
* generated/generated/minloc1_8_i2.c: Regenerated.
* generated/generated/minloc1_8_i4.c: Regenerated.
* generated/generated/minloc1_8_i8.c: Regenerated.
* generated/generated/minloc1_8_r10.c: Regenerated.
* generated/generated/minloc1_8_r16.c: Regenerated.
* generated/generated/minloc1_8_r4.c: Regenerated.
* generated/generated/minloc1_8_r8.c: Regenerated.
* generated/generated/minval_i16.c: Regenerated.
* generated/generated/minval_i1.c: Regenerated.
* generated/generated/minval_i2.c: Regenerated.
* generated/generated/minval_i4.c: Regenerated.
* generated/generated/minval_i8.c: Regenerated.
* generated/generated/minval_r10.c: Regenerated.
* generated/generated/minval_r16.c: Regenerated.
* generated/generated/minval_r4.c: Regenerated.
* generated/generated/minval_r8.c: Regenerated.
* generated/generated/product_c10.c: Regenerated.
* generated/generated/product_c16.c: Regenerated.
* generated/generated/product_c4.c: Regenerated.
* generated/generated/product_c8.c: Regenerated.
* generated/generated/product_i16.c: Regenerated.
* generated/generated/product_i1.c: Regenerated.
* generated/generated/product_i2.c: Regenerated.
* generated/generated/product_i4.c: Regenerated.
* generated/generated/product_i8.c: Regenerated.
* generated/generated/product_r10.c: Regenerated.
* generated/generated/product_r16.c: Regenerated.
* generated/generated/product_r4.c: Regen

[Bug fortran/49479] [4.6/4.7 Regression] reshape / optionals / zero sized arrays

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49479

--- Comment #11 from Thomas Koenig  2011-09-11 
09:16:08 UTC ---
Author: tkoenig
Date: Sun Sep 11 09:16:03 2011
New Revision: 178757

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=178757
Log:
2011-09-11  Thomas Koenig  

Backport fron trunk
PR fortran/49479
* generated/m4/ifunction.m4:  Always call internal_malloc_size
even when there is a zero-sized return array.
* generated/generated/maxloc1_16_i16.c: Regenerated.
* generated/generated/maxloc1_16_i1.c: Regenerated.
* generated/generated/maxloc1_16_i2.c: Regenerated.
* generated/generated/maxloc1_16_i4.c: Regenerated.
* generated/generated/maxloc1_16_i8.c: Regenerated.
* generated/generated/maxloc1_16_r10.c: Regenerated.
* generated/generated/maxloc1_16_r16.c: Regenerated.
* generated/generated/maxloc1_16_r4.c: Regenerated.
* generated/generated/maxloc1_16_r8.c: Regenerated.
* generated/generated/maxloc1_4_i16.c: Regenerated.
* generated/generated/maxloc1_4_i1.c: Regenerated.
* generated/generated/maxloc1_4_i2.c: Regenerated.
* generated/generated/maxloc1_4_i4.c: Regenerated.
* generated/generated/maxloc1_4_i8.c: Regenerated.
* generated/generated/maxloc1_4_r10.c: Regenerated.
* generated/generated/maxloc1_4_r16.c: Regenerated.
* generated/generated/maxloc1_4_r4.c: Regenerated.
* generated/generated/maxloc1_4_r8.c: Regenerated.
* generated/generated/maxloc1_8_i16.c: Regenerated.
* generated/generated/maxloc1_8_i1.c: Regenerated.
* generated/generated/maxloc1_8_i2.c: Regenerated.
* generated/generated/maxloc1_8_i4.c: Regenerated.
* generated/generated/maxloc1_8_i8.c: Regenerated.
* generated/generated/maxloc1_8_r10.c: Regenerated.
* generated/generated/maxloc1_8_r16.c: Regenerated.
* generated/generated/maxloc1_8_r4.c: Regenerated.
* generated/generated/maxloc1_8_r8.c: Regenerated.
* generated/generated/maxval_i16.c: Regenerated.
* generated/generated/maxval_i1.c: Regenerated.
* generated/generated/maxval_i2.c: Regenerated.
* generated/generated/maxval_i4.c: Regenerated.
* generated/generated/maxval_i8.c: Regenerated.
* generated/generated/maxval_r10.c: Regenerated.
* generated/generated/maxval_r16.c: Regenerated.
* generated/generated/maxval_r4.c: Regenerated.
* generated/generated/maxval_r8.c: Regenerated.
* generated/generated/minloc1_16_i16.c: Regenerated.
* generated/generated/minloc1_16_i1.c: Regenerated.
* generated/generated/minloc1_16_i2.c: Regenerated.
* generated/generated/minloc1_16_i4.c: Regenerated.
* generated/generated/minloc1_16_i8.c: Regenerated.
* generated/generated/minloc1_16_r10.c: Regenerated.
* generated/generated/minloc1_16_r16.c: Regenerated.
* generated/generated/minloc1_16_r4.c: Regenerated.
* generated/generated/minloc1_16_r8.c: Regenerated.
* generated/generated/minloc1_4_i16.c: Regenerated.
* generated/generated/minloc1_4_i1.c: Regenerated.
* generated/generated/minloc1_4_i2.c: Regenerated.
* generated/generated/minloc1_4_i4.c: Regenerated.
* generated/generated/minloc1_4_i8.c: Regenerated.
* generated/generated/minloc1_4_r10.c: Regenerated.
* generated/generated/minloc1_4_r16.c: Regenerated.
* generated/generated/minloc1_4_r4.c: Regenerated.
* generated/generated/minloc1_4_r8.c: Regenerated.
* generated/generated/minloc1_8_i16.c: Regenerated.
* generated/generated/minloc1_8_i1.c: Regenerated.
* generated/generated/minloc1_8_i2.c: Regenerated.
* generated/generated/minloc1_8_i4.c: Regenerated.
* generated/generated/minloc1_8_i8.c: Regenerated.
* generated/generated/minloc1_8_r10.c: Regenerated.
* generated/generated/minloc1_8_r16.c: Regenerated.
* generated/generated/minloc1_8_r4.c: Regenerated.
* generated/generated/minloc1_8_r8.c: Regenerated.
* generated/generated/minval_i16.c: Regenerated.
* generated/generated/minval_i1.c: Regenerated.
* generated/generated/minval_i2.c: Regenerated.
* generated/generated/minval_i4.c: Regenerated.
* generated/generated/minval_i8.c: Regenerated.
* generated/generated/minval_r10.c: Regenerated.
* generated/generated/minval_r16.c: Regenerated.
* generated/generated/minval_r4.c: Regenerated.
* generated/generated/minval_r8.c: Regenerated.
* generated/generated/product_c10.c: Regenerated.
* generated/generated/product_c16.c: Regenerated.
* generated/generated/product_c4.c: Regenerated.
* generated/generated/product_c8.c: Regenerated.
* generated/generated/product_i16.c: Regenerated.
* generated/generated/product_i1.c: Regenerated.
* generated/generated/product_i2.c: Regenerated.
* generated/generated/product_i4.c: Regenerated.
* generated/generated/product_i8.c: Regenerated.
* generated/generated/product_r10.c: Regenerated.
* generated/generated/product_r16.c: Regenerated.
* generated/gener