[Bug debug/55094] New: [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[Bug debug/55094] New: [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

             Bug #: 55094
           Summary: [4.7/4.8 Regression] ICE in maybe_record_trace_start,
                    at dwarf2cfi.c:2224
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: d.g.gorbachev@gmail.com


GCC 4.8, i686-pc-linux-gnu. Also happens in 4.7 configured with checking.

Compile this with `-g -Os -fomit-frame-pointer -fno-asynchronous-unwind-tables
-mpreferred-stack-boundary=2':

============== 8< ==============
extern int puts(const char *s);

int main(int argc, char **argv)
{
  if (argc) {
    puts(argv[0]);
    __builtin_trap();
  }
  __builtin_trap();
}
============== >8 ==============

1.c: In function 'main':
1.c:10:1: internal compiler error: in maybe_record_trace_start, at
dwarf2cfi.c:2224
 }
 ^
0x82cf181 maybe_record_trace_start
    ../../gcc-4.8/gcc/dwarf2cfi.c:2224
0x82cf56b scan_trace
    ../../gcc-4.8/gcc/dwarf2cfi.c:2401
0x82cf9cd create_cfi_notes
    ../../gcc-4.8/gcc/dwarf2cfi.c:2556
0x82cfcfa execute_dwarf2_frame
    ../../gcc-4.8/gcc/dwarf2cfi.c:2915
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug debug/55094] [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |i686-pc-linux-gnu
   Target Milestone|---                         |4.7.3

[Bug debug/55094] [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-11-13
                 CC|                            |jakub at gcc dot gnu.org,
                   |                            |rth at gcc dot gnu.org,
                   |                            |vmakarov at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-13 14:31:11 UTC ---
Doesn't ICE on the trunk anymore since LRA merge, apparently because LRA
decides for some reason to use frame pointer anyway, despite
-fomit-frame-pointer -Os.
CCing Vlad to see why.  Apparently it happens in:
665          if (ep->from_rtx == XEXP (x, 0)
666              || (ep->to_rtx == XEXP (x, 0)
667              && ep->to_rtx != hard_frame_pointer_rtx))
668            setup_can_eliminate (ep, false);
where ep->from_rtx is (frame), ep->to_rtx is (sp) and x is (pre_dec:SI
(reg/f:SI 7 sp)).
Is that intentional?

Anyway, testcase that also ICEs on 4.7 branch is e.g.
extern int puts (const char *);
int x;

int
main (int argc, char **argv)
{
  if (argc)
    {
      puts (argv[0]);
      x = 1;
      __builtin_unreachable ();
    }
  x = 1;
  __builtin_unreachable ();
}
with the same options - similar reason, crossjumping during jump2 crossjumps
bbs with different ARGS_SIZE final depth.  For noreturn calls we've handled it
by adding REG_ARGS_SIZE note on the noreturn call I think, for unconditional
TRAP_IF we perhaps could do the same, but not sure what we can do for
__builtin_unreachable which expands to nothing..., with no outgoing edge from
the bb at all.

[Bug debug/55094] [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-19 17:37:28 UTC ---
Created attachment 28734
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28734
gcc48-pr55094.patch

Untested fix.

[Bug debug/55094] [4.7/4.8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-20 08:38:22 UTC ---
Author: jakub
Date: Tue Nov 20 08:38:11 2012
New Revision: 193649

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=193649
Log:
    PR middle-end/55094
    * builtins.c (expand_builtin_trap): Add REG_ARGS_SIZE note
    on the trap insn for !ACCUMULATE_OUTGOING_ARGS.
    * cfgcleanup.c (outgoing_edges_match): Don't look at debug insns
    on the first old_insns_match_p call.  For !ACCUMULATE_OUTGOING_ARGS
    fail if the last real insn doesn't have REG_ARGS_SIZE note.

    * gcc.dg/pr55094.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr55094.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/builtins.c
    trunk/gcc/cfgcleanup.c
    trunk/gcc/testsuite/ChangeLog

[Bug debug/55094] [4.7 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.7/4.8 Regression] ICE in |[4.7 Regression] ICE in
                   |maybe_record_trace_start,   |maybe_record_trace_start,
                   |at dwarf2cfi.c:2224         |at dwarf2cfi.c:2224

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-20 08:42:46 UTC ---
Fixed on the trunk so far.

[Bug debug/55094] [4.7 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-checking
           Priority|P3                          |P2

[Bug debug/55094] [4.7 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-01 14:00:19 UTC ---
Author: jakub
Date: Fri Feb  1 14:00:12 2013
New Revision: 195650

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195650
Log:
    Backported from mainline
    2012-11-20  Jakub Jelinek  <jakub@redhat.com>

    PR middle-end/55094
    * builtins.c (expand_builtin_trap): Add REG_ARGS_SIZE note
    on the trap insn for !ACCUMULATE_OUTGOING_ARGS.
    * cfgcleanup.c (outgoing_edges_match): Don't look at debug insns
    on the first old_insns_match_p call.  For !ACCUMULATE_OUTGOING_ARGS
    fail if the last real insn doesn't have REG_ARGS_SIZE note.

    * gcc.dg/pr55094.c: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/pr55094.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/builtins.c
    branches/gcc-4_7-branch/gcc/cfgcleanup.c
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog

[Bug debug/55094] [4.7 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2224

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-01 14:25:07 UTC ---
Fixed.