[Bug c++/22488] [4.3/4.4/4.5/4.6 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[Bug c++/22488] [4.3/4.4/4.5/4.6 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.5                       |4.4.6

[Bug c++/22488] [4.3/4.4/4.5/4.6/4.7 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.6                       |4.4.7

[Bug c++/22488] [4.5/4.6/4.7/4.8 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.7                       |4.5.4

--- Comment #54 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-13 12:45:48 UTC ---
4.4 branch is being closed, moving to 4.5.4 target.

[Bug c++/22488] [4.6/4.7/4.8 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.5.4                       |4.6.4

[Bug c++/22488] [4.6/4.7/4.8 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

Steven Bosscher <steven at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |alias
             Status|ASSIGNED                    |WAITING
                 CC|dberlin at gcc dot gnu.org, |
                   |gcc-bugs at gcc dot         |
                   |gnu.org, mark at            |
                   |codesourcery dot com        |

--- Comment #55 from Steven Bosscher <steven at gcc dot gnu.org> 2012-11-09 22:37:34 UTC ---
-ENOPROGRESS

What is the status of this bug, Jason?

[Bug c++/22488] [4.6/4.7/4.8/4.9 Regression] push_fields_onto_fieldstack calculates offset incorrectly

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P5                          |P2
             Status|WAITING                     |NEW
         AssignedTo|jason at gcc dot gnu.org    |unassigned at gcc dot
                   |                            |gnu.org

--- Comment #56 from Jason Merrill <jason at gcc dot gnu.org> 2013-03-30 00:30:38 UTC ---
I still hope to get to this, but I don't anticipate it being a high priority
for me any time soon, so I'm going to unassign myself for now.  I'm also going
to bump up the priority again.

[Bug c++/22488] C++ frontend generates RECORD_TYPEs with overlapping FIELD_DECLs

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.4                       |---
            Summary|[4.6/4.7/4.8/4.9            |C++ frontend generates
                   |Regression]                 |RECORD_TYPEs with
                   |push_fields_onto_fieldstack |overlapping FIELD_DECLs
                   |calculates offset           |
                   |incorrectly                 |

--- Comment #57 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-02 08:04:05 UTC ---
Re-confirmed and summary adjusted.  The code in tree-ssa-structalias.c is
still there:

      /* We can't sort them if we have a field with a variable sized type,
         which will make notokay = true.  In that case, we are going to return
         without creating varinfos for the fields anyway, so sorting them is a
         waste to boot.  */
      if (!notokay)
        {
          sort_fieldstack (fieldstack);
          /* Due to some C++ FE issues, like PR 22488, we might end up
             what appear to be overlapping fields even though they,
             in reality, do not overlap.  Until the C++ FE is fixed,
             we will simply disable field-sensitivity for these cases.  */
          notokay = check_for_overlaps (fieldstack);

I am not aware of other code in the middle-end that might be confused
about this issue (well, SRA maybe, but it handles overlaps well as it
also handles accesses to unions).

I believe that the C++ frontend issue might not be a regression after all,
the tree-ssa-structalias.c "regression" was fixed by the above kludge.

The C++ frontend issue makes it impossible to implement a GENERIC verifier
for RECORD_TYPEs (verify FIELD_DECLs are sorted after offset and not
overlapping).

[Bug c++/22488] C++ frontend generates RECORD_TYPEs with overlapping FIELD_DECLs

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22488

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

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

--- Comment #58 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2013-04-02 14:37:43 UTC ---
> The C++ frontend issue makes it impossible to implement a GENERIC verifier
> for RECORD_TYPEs (verify FIELD_DECLs are sorted after offset and not
> overlapping).

To be fair, I think that the Ada front-end still has the same issue.  We fixed
the biggest source (constrained subtypes of record types with variant part) a
few releases ago, but there is still one problematic case (record type with
variant part and partial representation clause).