[Bug debug/28834] New: [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[Bug debug/28834] New: [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

Testcase that crashes at -O3 -g:
struct S { short x; };
typedef struct S __attribute__((__may_alias__)) test;

int f() {
  int a=10;
  test *p=(test *)&a;
  p->x = 1;
  return a;
}

int main() {
  if (f() == 10)
    __builtin_abort();
  return 0;
}

---------------------
mayalias-2.c:2: internal compiler error: in splice_child_die, at
dwarf2out.c:5513
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when
                    using may_alias and structs
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2006-08-24 11:06 -------
This worked in 3.4.0 so this is a regression.  Note this is the testcase for
28807 which I was using for testing so the testcase might be added to the
testsuite by the time someone gets around to looking into the bug.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.0.0 4.1.0 4.2.0
      Known to work|                            |3.4.0
   Target Milestone|---                         |4.0.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-08-24 15:50 -------
Janis,
  Could you run a regression hunt on this bug?


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |janis at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[janis at gcc dot gnu dot org]

------- Comment #3 from janis at gcc dot gnu dot org  2006-08-24 23:35 -------
A regression hunt on powerpc-linux identified this patch:

    http://gcc.gnu.org/viewcvs?view=rev&rev=87036

    r87036 | dpatel | 2004-09-03 17:10:40 +0000 (Fri, 03 Sep 2004)


-- 

janis at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dpatel at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2006-08-25 01:20 -------
Confirmed by Janis.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
 GCC target triplet|i686-pc-linux-gnu           |dwarf2
   Last reconfirmed|0000-00-00 00:00:00         |2006-08-25 01:20:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2006-08-25 10:39 -------
We now have gcc.c-torture/execute/mayalias-2.c which crashes this way on x86_64
at  -O3 -g.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[danglin at gcc dot gnu dot org]

------- Comment #6 from danglin at gcc dot gnu dot org  2006-08-26 23:39 -------
Also fails on PA with -O3 -g.


-- 

danglin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |danglin at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2006-08-29 04:41 -------
*** Bug 28880 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |geoffk at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[geoffk at gcc dot gnu dot org]

------- Comment #8 from geoffk at gcc dot gnu dot org  2006-08-29 04:48 -------
In the duplicate I explain:

The problem is that the front-end is calling the DWARF output code with two
shallow copies of the same structure, 'S'.  The DWARF code detects that two
different structures have the same members and aborts.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #9 from pinskia at gcc dot gnu dot org  2006-08-30 03:28 -------
Devang,
  Why did you remove your self, you caused this regression.
Yes you might not work on GCC any more for Apple but that does not take you
away from fixing the regression you caused.  I am a bit upset at this behavior
of going away and not going to fix a regression you caused.

-- Pinski

dpatel@apple.com        2006-08-29 17:46:15     CC      dpatel@gcc.gnu.org


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dpatel at apple dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[dpatel at apple dot com]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 752 bytes --]



------- Comment #10 from dpatel at apple dot com  2006-08-30 07:47 -------
Pinski,

Please do not reinsert my email address in CC list, again (and learn to not
jump to conclusion based on biased views)

May be it is not a good idea to ask dwarf generator to handle a case where two
shallow copy of same struct refers same field ? May
be equate_decl_number_to_die() should handle it properly ? May be it is
appropriate to have one field be a member of multiple structures ?


-- 

dpatel at apple dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|dpatel at apple dot com     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[mmitchel at gcc dot gnu dot org]

------- Comment #11 from mmitchel at gcc dot gnu dot org  2006-09-01 21:53 -------
Yet another problem showing problems with attributes on typedefs for structure
types...


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #12 from pinskia at gcc dot gnu dot org  2006-09-02 00:02 -------
(In reply to comment #11)
> Yet another problem showing problems with attributes on typedefs for structure
> types...
Except this is with C and not C++ unlike the other ones.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[geoffk at geoffk dot org]

------- Comment #13 from geoffk at geoffk dot org  2006-09-02 05:31 -------
Subject: Re:  [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using
may_alias and structs


On 01/09/2006, at 2:53 PM, mmitchel at gcc dot gnu dot org wrote:

> ------- Comment #11 from mmitchel at gcc dot gnu dot org   
> 2006-09-01 21:53 -------
> Yet another problem showing problems with attributes on typedefs  
> for structure
> types...

The question I asked is "why doesn't this happen for 'const'"?  That  
turned out to be a good question, because it leads to the better  
question of "what debugging output did you expect for this code,  
anyway"?

It seems to me that __noalias__ is an interesting attribute that  
should be somehow reflected in the DWARF.  That would require a GNU  
extension, of course.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[rsandifo at gcc dot gnu dot org]

------- Comment #14 from rsandifo at gcc dot gnu dot org  2006-10-07 12:56 -------
The mayalias-2.c failure shows up on MIPS too.


-- 

rsandifo at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2 Regression] -O3 -g crashes sometimes when using may_alias and structs

[ebotcazou at gcc dot gnu dot org]

------- Comment #15 from ebotcazou at gcc dot gnu dot org  2006-10-15 11:38 -------
Also fails on SPARC with -O3 -g.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #16 from pinskia at gcc dot gnu dot org  2006-11-20 00:49 -------
*** Bug 29903 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[acahalan at gmail dot com]

------- Comment #17 from acahalan at gmail dot com  2006-11-24 00:11 -------
(In reply to comment #13)

> The question I asked is "why doesn't this happen for 'const'"?  That  
> turned out to be a good question, because it leads to the better  
> question of "what debugging output did you expect for this code,  
> anyway"?
> 
> It seems to me that __noalias__ is an interesting attribute that  
> should be somehow reflected in the DWARF.  That would require a GNU  
> extension, of course.

Rather than comparing this with "const", compare it with "restrict".
This deserves representation in DWARF if and only if restrict deserves it.
(and that I can't answer, but my gut feeling is that such representation
should be only for things that C++ would put into name mangling)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #18 from pinskia at gcc dot gnu dot org  2007-02-01 08:49 -------
*** Bug 30661 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |brooks at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[gdr at gcc dot gnu dot org]

------- Comment #19 from gdr at gcc dot gnu dot org  2007-02-03 19:35 -------
won't fix in GCC-4.0.x.  Adjusting milestone.


-- 

gdr at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.4                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.3                       |4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[hp at gcc dot gnu dot org]

------- Comment #20 from hp at gcc dot gnu dot org  2007-02-05 13:51 -------
I see this for cris-elf (r121581) and mmix-knuth-mmixware (r121569) too, both
mayalias-2 and -3 both at "-O3 -g" like for x86_64.
As we have this PR, I intend to XFAIL it for these ports with those options;
IIRC that's protocol.


-- 

hp at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hp at gcc dot gnu dot org
   Last reconfirmed|2006-10-26 08:10:02         |2007-02-05 13:51:52
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #21 from pinskia at gcc dot gnu dot org  2007-02-10 19:23 -------
*** Bug 30758 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Jean-pierre dot vial at
                   |                            |wanadoo dot fr


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.1.2                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[rguenth at gcc dot gnu dot org]

------- Comment #22 from rguenth at gcc dot gnu dot org  2007-02-20 21:49 -------
*** Bug 30894 has been marked as a duplicate of this bug. ***


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |timj at gtk dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -O3 -g crashes sometimes when using may_alias and structs

[pinskia at gcc dot gnu dot org]

------- Comment #23 from pinskia at gcc dot gnu dot org  2007-02-27 21:48 -------
*** Bug 30986 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |schwab at suse dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs

[schwab at suse dot de]

------- Comment #24 from schwab at suse dot de  2007-02-27 21:54 -------
ICE's with every optimization level.


-- 

schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.0/4.1/4.2/4.3 Regression]|[4.0/4.1/4.2/4.3 Regression]
                   |-O3 -g crashes sometimes    |-g crashes sometimes when
                   |when using may_alias and    |using may_alias and structs
                   |structs                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[pinskia at gcc dot gnu dot org]

------- Comment #25 from pinskia at gcc dot gnu dot org  2007-06-20 14:30 -------
*** Bug 32426 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kazu at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[pinskia at gcc dot gnu dot org]

------- Comment #26 from pinskia at gcc dot gnu dot org  2007-07-17 12:51 -------
*** Bug 32793 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rosana07a at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[tprince at computer dot org]

------- Comment #27 from tprince at computer dot org  2007-07-29 18:00 -------
same failure for gcc-4.3 mainline on i686-pc-cygwin


-- 

tprince at computer dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tprince at computer dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[jason at gcc dot gnu dot org]

-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jason at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-02-05 13:51:52         |2007-10-24 19:59:54
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[pinskia at gcc dot gnu dot org]

------- Comment #28 from pinskia at gcc dot gnu dot org  2007-11-09 18:21 -------
*** Bug 34041 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[jason at gcc dot gnu dot org]

------- Comment #29 from jason at gcc dot gnu dot org  2007-11-19 21:24 -------
*** Bug 29436 has been marked as a duplicate of this bug. ***


-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |acahalan at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[jason at gcc dot gnu dot org]

------- Comment #30 from jason at gcc dot gnu dot org  2007-11-19 22:32 -------
Subject: Bug 28834

Author: jason
Date: Mon Nov 19 22:32:30 2007
New Revision: 130298

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130298
Log:
note PR 28834

Modified:
    trunk/gcc/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[jason at gcc dot gnu dot org]

------- Comment #31 from jason at gcc dot gnu dot org  2007-11-19 22:34 -------
The crash is fixed by ignoring the attribute on the typedef.  If you want to
apply may_alias to a struct type, you need to specify it in the type
definition, either as

struct __attribute ((may_alias)) name { ... };

or

struct name { ... } __attribute ((may_alias));


-- 

jason at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834

[Bug debug/28834] [4.0/4.1/4.2/4.3 Regression] -g crashes sometimes when using may_alias and structs (ICE in splice_child_die)

[ghazi at gcc dot gnu dot org]

------- Comment #32 from ghazi at gcc dot gnu dot org  2008-02-07 19:14 -------
Jason - Should the fix for PR28834 (AKA PR29436) be backported to 4.2/4.1?

I still see errors from mayalias-2.c on 4.2.  (4.1 doesn't have the testcase,
but I suspect it still has the bug.)


-- 

ghazi at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ghazi at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28834