[Bug lto/47889] New: Segmentation fault in lto1

[Bug lto/47889] New: Segmentation fault in lto1

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

           Summary: Segmentation fault in lto1
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: d.g.gorbachev@gmail.com


Testcase in attachment 23461

$ gcc -O -flto -DPR47889 main.c s.c
[...]
main.c:5:5: internal compiler error: Segmentation fault
[...]

[Bug lto/47889] Segmentation fault in lto1

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #1 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> 2011-02-27 19:54:50 UTC ---
Created attachment 23485
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23485
Backtrace

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.6.1

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.06.12 13:00:56
     Ever Confirmed|0                           |1

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-06-12 13:00:56 UTC ---
Confirmed.  We should diagnose this.

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.1                       |4.6.2

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-06-27 12:33:10 UTC ---
GCC 4.6.1 is being released.

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-07-12 21:17:31 UTC ---
(In reply to comment #2)
> Confirmed.  We should diagnose this.
We do:
t.c:1:13: warning: type of ‘s’ does not match original declaration [enabled by
default]
t1.c:1:14: note: previously declared here
--- CUT ---
But we don't error out.

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-07-12 21:20:57 UTC ---
Yeah, well.  There are "legitimate" cases (read: in SPEC2k6), so we can't
error out in general (the cases are mixing float and int for example).

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.2                       |4.6.3

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-10-26 17:13:56 UTC ---
GCC 4.6.2 is being released.

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #7 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> 2011-10-26 19:36:10 UTC ---
Created attachment 25620
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25620
Testcase

Still fails with this testcase.

[Bug lto/47889] [4.6/4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.3                       |4.6.4

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-01 14:39:14 UTC ---
GCC 4.6.3 is being released.

[Bug lto/47889] [4.7/4.8/4.9 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.4                       |4.7.4

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-12 15:17:07 UTC ---
GCC 4.6.4 has been released and the branch has been closed.

[Bug lto/47889] [4.7/4.8/4.9 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[aldyh at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aldyh at gcc dot gnu.org

--- Comment #10 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
Can we remove 4.7, 4.8, and 4.9 from the failing targets?  It seems we diagnose
it just fine and we don't even error out (just a warning).  This is what we get
on 4.8 and 4.9:

reynosa:/dev/shm/trunk/gcc$ ./xgcc -B./ main.c s.c  -flto -O -DPR47889
main.c:1:13: warning: type of 's' does not match original declaration [enabled
by default]
 extern char s[1];
             ^
s.c:1:14: note: previously declared here
 struct S { } s;
              ^

Similarly for 4.7:

reynosa:/build/pristine-4_7/gcc$ ./xgcc -B./ main.c s.c  -flto -O -DPR47889
In file included from :0:0:
main.c:1:13: warning: type of 's' does not match original declaration [enabled
by default]
In file included from main.c:3:0,
                 from :0:
s.c:1:14: note: previously declared here

So I don't see any segfault as reported in the PR.  And I don't see any hard
error (since Richi said we shouldn't error, which we don't...).

The only place where I see an ICE is in 4.6:

reynosa:/build/pristine-4.6/gcc$ ./xgcc -B./ main.c s.c  -flto -O -DPR47889
main.c:1:13: warning: type of 's' does not match original declaration [enabled
by default]
s.c:1:14: note: previously declared here
In file included from :0:0:
main.c: In function 'main':
main.c:5:5: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
lto-wrapper: ./xgcc returned 1 exit status
/usr/bin/ld: lto-wrapper failed
collect2: ld returned 1 exit status

Can we just flag this exclusively as a 4.6 problem?

[Bug lto/47889] [4.7/4.8/4.9 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[aldyh at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING

[Bug lto/47889] [4.7/4.8/4.9 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #11 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> ---
GCC 4.7 still crashes on the testcase from attachment 25620:

$ gcc -r -nostdlib -flto 1.c 2.c
In file included from 1.c:5:0,
                 from :0:
2.c:5:17: warning: type of 's' does not match original declaration [enabled by
default]
In file included from :0:0:
1.c:5:10: note: previously declared here
In file included from 1.c:5:0,
                 from :1:
2.c: In function 'foo':
2.c:10:5: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.

[Bug lto/47889] [4.7/4.8/4.9 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[aldyh at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #12 from Aldy Hernandez <aldyh at redhat dot com> ---
On 01/09/14 15:43, d.g.gorbachev at gmail dot com wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889
>
> --- Comment #11 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> ---
> GCC 4.7 still crashes on the testcase from attachment 25620:
>
> $ gcc -r -nostdlib -flto 1.c 2.c
> In file included from 1.c:5:0,
>                   from :0:
> 2.c:5:17: warning: type of 's' does not match original declaration [enabled by
> default]
> In file included from :0:0:
> 1.c:5:10: note: previously declared here
> In file included from 1.c:5:0,
>                   from :1:
> 2.c: In function 'foo':
> 2.c:10:5: internal compiler error: Segmentation fault
> Please submit a full bug report,
> with preprocessed source if appropriate.
>

Which version of 4.7?

So in essence, 4.8 and 4.9 do not exhibit this behavior.  I will remove 
the 4.8 and 4.9 tags.

[Bug lto/47889] [4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #13 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> ---
It was 4.7.4 20131207 (prerelease).

[Bug lto/47889] [4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[aldyh at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #14 from Aldy Hernandez <aldyh at redhat dot com> ---
On 01/09/14 16:01, d.g.gorbachev at gmail dot com wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889
>
> --- Comment #13 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> ---
> It was 4.7.4 20131207 (prerelease).
>

Can you try the actual release?  4.7.4, not the prerelease?

[Bug lto/47889] [4.7 Regression] Segmentation fault in useless_type_conversion_p, at tree-ssa.c:1228

[d.g.gorbachev at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

--- Comment #16 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> ---
Created attachment 31801
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31801&action=edit
Backtrace from non-checked 4.7.4 build

[Bug lto/47889] [4.7 Regression] Segmentation fault in array_ref_element_size / useless_type_conversion_p

[aldyh at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

Aldy Hernandez <aldyh at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW

[Bug lto/47889] [4.7 Regression] Segmentation fault in array_ref_element_size / useless_type_conversion_p

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47889

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|4.7.4                       |4.8.3
      Known to fail|                            |4.7.4

--- Comment #17 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for 4.8.3.