[Bug c/54552] New: Cast to pointer to VLA crash the compiler

[Bug c/54552] New: Cast to pointer to VLA crash the compiler

[jens.gustedt at loria dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

             Bug #: 54552
           Summary: Cast to pointer to VLA crash the compiler
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jens.gustedt@loria.fr


Created attachment 28172
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28172
code to reproduce the problem

I stumbled int to a case where a cast (double(*)[n]) crashes the compiler,
whereas first having a typedef for the VLA works ok.

I attach code that reproduces the problem for me. The bug is present as well in
gcc 4.6.3 as in 4.7.0. This is on an ubuntu x86_64, but I don't think that this
should matter.

Jens

[Bug c/54552] Cast to pointer to VLA crash the compiler

[jens.gustedt at loria dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

--- Comment #1 from Jens Gustedt <jens.gustedt at loria dot fr> 2012-09-11 16:11:59 UTC ---
The compiler error is

test-p99-gcc-bug.c:9:6: internal compiler error: in gimplify_expr, at
gimplify.c:7584

[Bug c/54552] [4.6/4.7/4.8 Regression] Cast to pointer to VLA crash the compiler

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-09-11
                 CC|                            |jakub at gcc dot gnu.org
   Target Milestone|---                         |4.6.4
            Summary|Cast to pointer to VLA      |[4.6/4.7/4.8 Regression]
                   |crash the compiler          |Cast to pointer to VLA
                   |                            |crash the compiler
     Ever Confirmed|0                           |1

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-09-11 16:18:17 UTC ---
Fails since http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145254

[Bug c/54552] [4.6/4.7/4.8 Regression] Cast to pointer to VLA crash the compiler

[jsm28 at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

--- Comment #3 from Joseph S. Myers <jsm28 at gcc dot gnu.org> 2012-09-14 21:17:00 UTC ---
Author: jsm28
Date: Fri Sep 14 21:16:56 2012
New Revision: 191313

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=191313
Log:
c:
    PR c/54552
    * c-typeck.c (c_cast_expr): When casting to a type requiring
    C_MAYBE_CONST_EXPR to be created, pass the inner expression to
    c_fully_fold first.

testsuite:
    * gcc.c-torture/compile/pr54552-1.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr54552-1.c
Modified:
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-typeck.c
    trunk/gcc/testsuite/ChangeLog

[Bug c/54552] [4.6/4.7 Regression] Cast to pointer to VLA crash the compiler

[jsm28 at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

Joseph S. Myers <jsm28 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.6/4.7/4.8 Regression]    |[4.6/4.7 Regression] Cast
                   |Cast to pointer to VLA      |to pointer to VLA crash the
                   |crash the compiler          |compiler

--- Comment #4 from Joseph S. Myers <jsm28 at gcc dot gnu.org> 2012-09-14 21:18:35 UTC ---
Fixed so far for trunk, pending testing fix for 4.7 and 4.6.

[Bug c/54552] [4.6/4.7 Regression] Cast to pointer to VLA crash the compiler

[jsm28 at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

--- Comment #5 from Joseph S. Myers <jsm28 at gcc dot gnu.org> 2012-09-15 00:29:31 UTC ---
Author: jsm28
Date: Sat Sep 15 00:29:28 2012
New Revision: 191337

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=191337
Log:
    PR c/54552
    * c-typeck.c (c_cast_expr): When casting to a type requiring
    C_MAYBE_CONST_EXPR to be created, pass the inner expression to
    c_fully_fold first.

testsuite:
    * gcc.c-torture/compile/pr54552-1.c: New test.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/gcc.c-torture/compile/pr54552-1.c
Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/c-typeck.c
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog

[Bug c/54552] [4.6/4.7 Regression] Cast to pointer to VLA crash the compiler

[jsm28 at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

Joseph S. Myers <jsm28 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.4                       |4.7.2

--- Comment #6 from Joseph S. Myers <jsm28 at gcc dot gnu.org> 2012-09-15 00:31:49 UTC ---
Fixed for 4.6.4, 4.7 branch fix to follow after 4.7.2 is released.

[Bug c/54552] [4.6/4.7 Regression] Cast to pointer to VLA crash the compiler

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.7.2                       |4.7.3

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-09-20 10:13:00 UTC ---
GCC 4.7.2 has been released.

[Bug c/54552] [4.6/4.7 Regression] Cast to pointer to VLA crash the compiler

[jsm28 at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

--- Comment #8 from Joseph S. Myers <jsm28 at gcc dot gnu.org> 2012-09-20 20:50:27 UTC ---
Author: jsm28
Date: Thu Sep 20 20:50:17 2012
New Revision: 191591

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=191591
Log:
    PR c/54552
    * c-typeck.c (c_cast_expr): When casting to a type requiring
    C_MAYBE_CONST_EXPR to be created, pass the inner expression to
    c_fully_fold first.

testsuite:
    * gcc.c-torture/compile/pr54552-1.c: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.c-torture/compile/pr54552-1.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/c-typeck.c
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog

[Bug c/54552] [4.6/4.7 Regression] Cast to pointer to VLA crash the compiler

[jsm28 at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54552

Joseph S. Myers <jsm28 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.7.3                       |4.6.4

--- Comment #9 from Joseph S. Myers <jsm28 at gcc dot gnu.org> 2012-09-20 20:55:24 UTC ---
Fixed for 4.6.4, 4.7.3, 4.8.0.