* [PATCH] PR fortran/51434 -- ICE in gfc_simplify_transfer
@ 2018-02-26 20:15 Steve Kargl
2018-03-01 20:45 ` Thomas Koenig
0 siblings, 1 reply; 3+ messages in thread
From: Steve Kargl @ 2018-02-26 20:15 UTC (permalink / raw)
To: fortran, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 1085 bytes --]
All,
The attached patch fixes an ICE that occurs in gfc_simplify_tranfer.
The code that causes the problem is
if (!gfc_is_constant_expr (source)
|| (gfc_init_expr_flag && !gfc_is_constant_expr (mold))
|| !gfc_is_constant_expr (size))
return NULL;
in particular gfc_is_constant_expr (mold) leads to segfault. Removing
the 2nd line allows the testcase to compile, but leads to several
regressions. I went down the rabbit with gdb-8.0.1 to see why this
was dying a horrible death, and came away with a large headache.
After conferring with F95 and F2018, I concluded (and I coudl be
wrong) that mold simply needs to available as a scalar or an
array and it's actual value was not needed. So, I decided to
use gfc_reduce_expr (mold) to see if this would fix up some
rogue pointer, and well it worked. So, OK to commit?
2018-02-26 Steven G. Kargl <kargl@gcc.gnu.org>
PF fortran/51434
* simplify.c (gfc_simplify_transfer): Reduce mold.
2018-02-26 Steven G. Kargl <kargl@gcc.gnu.org>
PF fortran/51434
* gfortran.dg/pr51434.f90: New test.
--
Steve
[-- Attachment #2: pr51434.diff --]
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Index: gcc/fortran/simplify.c
===================================================================
--- gcc/fortran/simplify.c (revision 258006)
+++ gcc/fortran/simplify.c (working copy)
@@ -25,6 +25,7 @@ along with GCC; see the file COPYING3. If not see
#include "gfortran.h"
#include "arith.h"
#include "intrinsic.h"
+#include "match.h"
#include "target-memory.h"
#include "constructor.h"
#include "version.h" /* For version_string. */
@@ -7370,10 +7371,12 @@ gfc_simplify_transfer (gfc_expr *source, gfc_expr *mol
unsigned char *buffer;
size_t result_length;
+ if (!gfc_is_constant_expr (source) || !gfc_is_constant_expr (size))
+ return NULL;
- if (!gfc_is_constant_expr (source)
- || (gfc_init_expr_flag && !gfc_is_constant_expr (mold))
- || !gfc_is_constant_expr (size))
+ if (!gfc_resolve_expr (mold))
+ return NULL;
+ if (gfc_init_expr_flag && !gfc_is_constant_expr (mold))
return NULL;
if (!gfc_calculate_transfer_sizes (source, mold, size, &source_size,
Index: gcc/testsuite/gfortran.dg/pr51434.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr51434.f90 (nonexistent)
+++ gcc/testsuite/gfortran.dg/pr51434.f90 (working copy)
@@ -0,0 +1,19 @@
+! { dg-do run }
+! PR fortran/51434
+module foo
+ implicit none
+ integer, parameter :: n = 5
+ character(len=1), parameter :: s(n) = 'a'
+ type :: a
+ integer :: m = n
+ character(len=1):: t(n) = transfer('abcde ', s)
+ end type a
+end module foo
+
+program bar
+ use foo
+ implicit none
+ type(a) c
+ if (c%m /= n) stop 1
+ if (any(c%t /= ['a', 'b', 'c', 'd', 'e'])) stop 2
+end program bar
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] PR fortran/51434 -- ICE in gfc_simplify_transfer
2018-02-26 20:15 [PATCH] PR fortran/51434 -- ICE in gfc_simplify_transfer Steve Kargl
@ 2018-03-01 20:45 ` Thomas Koenig
2018-03-01 21:01 ` Steve Kargl
0 siblings, 1 reply; 3+ messages in thread
From: Thomas Koenig @ 2018-03-01 20:45 UTC (permalink / raw)
To: sgk, fortran, gcc-patches
Hi Steve,
> 2018-02-26 Steven G. Kargl <kargl@gcc.gnu.org>
>
> PF fortran/51434
> * simplify.c (gfc_simplify_transfer): Reduce mold.
I think this should be "Resolve" (at least that is what your
patch shows).
OK for trunk, thanks for the patch!
Regards
Thomas
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] PR fortran/51434 -- ICE in gfc_simplify_transfer
2018-03-01 20:45 ` Thomas Koenig
@ 2018-03-01 21:01 ` Steve Kargl
0 siblings, 0 replies; 3+ messages in thread
From: Steve Kargl @ 2018-03-01 21:01 UTC (permalink / raw)
To: Thomas Koenig; +Cc: fortran, gcc-patches
On Thu, Mar 01, 2018 at 09:44:57PM +0100, Thomas Koenig wrote:
> Hi Steve,
>
> > 2018-02-26 Steven G. Kargl <kargl@gcc.gnu.org>
> >
> > PF fortran/51434
> > * simplify.c (gfc_simplify_transfer): Reduce mold.
>
> I think this should be "Resolve" (at least that is what your
> patch shows).
>
> OK for trunk, thanks for the patch!
>
Yes, I noticed that typo. I tried gfc_reduce_expr and
gfc_simplify_expr, but both gave the ICE. gfc_resolve_expr
works.
--
Steve
^ permalink raw reply [flat|nested] 3+ messages in thread
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