[Bug c++/42317] New: [4.5 Regression] Issues with comdat virtual dtors

[Bug c++/42317] New: [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

cat > T.C <<\EOF
// { dg-do link }
// { dg-options "-O0" }
// { dg-additional-sources "T-aux.cc" }

#include "T.h"

D::D (int x) : C (x) {}

int
main ()
{
}
EOF
cat > T.h <<\EOF
struct A
{
  A ();
  ~A ();
};

struct B
{
  A b;
  virtual void mb ();
  B (int);
  virtual ~B ();
};

struct C : public B
{
  virtual void mc ();
  C (int);
  ~C ();
};

inline C::~C () {}

struct D : public C
{
  A d;
  D (int);
  ~D ();
};
EOF
cat > T-aux.cc <<\EOF
#include "T.h"

A::A () {}
A::~A () {}

void B::mb () {}
B::B (int) {}
B::~B () {}

void C::mc () {}
C::C (int x) : B (x) {}

D::~D () {}
EOF
g++ -o T T.c T-aux.cc
fails on powerpc64-linux with:
`C::~C()' referenced in section `.data.rel.ro._ZTV1C[vtable for C]' of
/tmp/ccnVbxT3.o: defined in discarded section `_ZN1CD5Ev' of /tmp/ccnVbxT3.o

While this doesn't fail to link on e.g. x86_64-linux, even there it is buggy:
grep ZN1CD.*comdat T.s; echo $?; grep ZN1CD.*comdat T-aux.s
.section.text._ZN1CD2Ev,"axG",@progbits,_ZN1CD5Ev,comdat
0
.section.text._ZN1CD2Ev,"axG",@progbits,_ZN1CD5Ev,comdat
.section.text._ZN1CD0Ev,"axG",@progbits,_ZN1CD5Ev,comdat

Deleting dtor wasn't emitted in T.s (no vtable is emitted there either).

So I'm afraid we either need to add further restrictions on when we actually do
optimize same body dtors (but have no idea at this point what that restriction
would be, appart from disabling the optimization for virtual destructors,
Jason, any ideas?), or would need to accept some bloat from time to time and
change cgraph to force in also the deleting dtor if samebody complete/base dtor
aliases are emitted in the D5 group.


-- 
           Summary: [4.5 Regression] Issues with comdat virtual dtors
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
GCC target triplet: powerpc64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu dot
                   |                            |org
           Priority|P1                          |P3
   Target Milestone|4.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2009-12-07 12:55 -------
Created an attachment (id=19248)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19248&action=view)
gcc45-pr42317.patch

Untested patch to implement the (admittedly ugly) cgraph changes to force
D0 to be output together with D[12] aliases in D5 comdat groups and accepts
some limited bloat in rare cases (in exchange of often saving space because
more dtors can be same body optimized).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[debian-gcc at lists dot debian dot org]

------- Comment #2 from debian-gcc at lists dot debian dot org  2009-12-08 08:56 -------
with the proposed patch applied, the build fails now with:

virtual __gnu_cxx::stdio_sync_filebuf<wchar_t>::~stdio_sync_filebuf()/243(191)
@0x4093abd0 availability:available 22 time, 11 benefit (
24 after inlining) 4 size, 2 benefit (6 after inlining) reachable body
externally_visible finalized inlinable
  called by: 
  calls: void operator delete(void*)/317 (1.00 per call)
__gnu_cxx::stdio_sync_filebuf<wchar_t>::~stdio_sync_filebuf()/113 (inlined) (1
.00 per call) 
../../../../src/libstdc++-v3/src/ios_init.cc:199:1: internal compiler error:
failed to reclaim unneeded function
Please submit a full bug report,
with preprocessed source if appropriate.

the file ios_init.ii builds with -O0, but not with -O1 or higher

  Matthias


-- 

debian-gcc at lists dot debian dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |debian-gcc at lists dot
                   |                            |debian dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[debian-gcc at lists dot debian dot org]

------- Comment #3 from debian-gcc at lists dot debian dot org  2009-12-08 08:58 -------
Created an attachment (id=19256)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19256&action=view)
preprocessed source


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2009-12-08 09:03 -------
You were testing the patch attached here (i.e. version before
bootstrap/regtest) instead of the one posted to gcc-patches (tested), right?
http://gcc.gnu.org/ml/gcc-patches/2009-12/msg00385.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[doko at ubuntu dot com]

------- Comment #5 from doko at ubuntu dot com  2009-12-08 12:36 -------
yes, re-testing with the version from the ML. currently passed the libstdc++
build.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[debian-gcc at lists dot debian dot org]

------- Comment #6 from debian-gcc at lists dot debian dot org  2009-12-08 12:37 -------
*** Bug 42323 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[jakub at gcc dot gnu dot org]

------- Comment #7 from jakub at gcc dot gnu dot org  2009-12-10 21:59 -------
Subject: Bug 42317

Author: jakub
Date: Thu Dec 10 21:58:49 2009
New Revision: 155143

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155143
Log:
        PR c++/42317
        * cgraph.h (struct cgraph_node): Add same_comdat_group field.
        * cgraph.c (cgraph_remove_node): Unchain node from same_comdat_group
        circular list.
        (cgraph_node_can_be_local_p): Return false for DECL_COMDAT with
        node->same_comdat_group.
        * ipa.c (cgraph_remove_unreachable_nodes): For any reachable node
        mark all its same_comdat_group nodes as also reachable.
        (cgraph_externally_visible_p): Return true even if any of
        same_comdat_group nodes has address taken.
        * lto-cgraph.c (lto_output_node): Stream out same_comdat_group.
        (output_cgraph): Ensure other same_comdat_group nodes are also
        included.
        (input_node): Stream in same_comdat_group.
        (input_cgraph_1): Fix up same_comdat_group fields from references
        to pointers.
        * cgraphunit.c (cgraph_analyze_functions): Mark all other
        same_comdat_group nodes as reachable.
        (cgraph_mark_functions_to_output): For each node->process process
        also other same_comdat_group nodes.
        * ipa-inline.c (cgraph_clone_inlined_nodes): Don't reuse nodes
        with same_comdat_group non-NULL.
        (cgraph_mark_inline_edge): Likewise.

        * decl2.c (cp_write_global_declarations): Clear DECL_EXTERNAL
        also on all other functions in the same comdat group.
        * optimize.c (maybe_clone_body): Also optimize virtual implicit
        dtors.  For virtual comdat dtors tell cgraph that base and deleting
        dtor are in the same comdat group.

        * config/abi/pre/gnu.ver: Don't export certain base dtors that
        weren't previously exported.

        * g++.dg/opt/dtor2.C: New test.
        * g++.dg/opt/dtor2.h: New file.
        * g++.dg/opt/dtor2-aux.cc: New file.

Added:
    trunk/gcc/testsuite/g++.dg/opt/dtor2-aux.cc
    trunk/gcc/testsuite/g++.dg/opt/dtor2.C
    trunk/gcc/testsuite/g++.dg/opt/dtor2.h
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/cgraph.c
    trunk/gcc/cgraph.h
    trunk/gcc/cgraphunit.c
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl2.c
    trunk/gcc/cp/optimize.c
    trunk/gcc/ipa-inline.c
    trunk/gcc/ipa.c
    trunk/gcc/lto-cgraph.c
    trunk/gcc/testsuite/ChangeLog
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/config/abi/pre/gnu.ver


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[hjl at gcc dot gnu dot org]

------- Comment #8 from hjl at gcc dot gnu dot org  2009-12-11 23:38 -------
Subject: Bug 42317

Author: hjl
Date: Fri Dec 11 23:36:24 2009
New Revision: 155184

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155184
Log:
Backport testcases from trunk.

2009-12-11  H.J. Lu  <hongjiu.lu@intel.com>

        Backport from mainline:
        2009-12-11  Dodji Seketeli  <dodji@redhat.com>

        PR c++/42225
        * g++.dg/template/typedef24.C: New test.
        * g++.dg/template/typedef25.C: New test.

        2009-12-11  Dodji Seketeli  <dodji@redhat.com>

        PR c++/42251
        * g++.dg/template/const3.C: New test.

        2009-12-10  Jakub Jelinek  <jakub@redhat.com>

        PR c++/42317
        * g++.dg/opt/dtor2.C: New test.
        * g++.dg/opt/dtor2.h: New file.
        * g++.dg/opt/dtor2-aux.cc: New file.

        2009-12-10  Jan Hubicka  <jh@suse.cz>

        PR middle-end/42110
        * g++.dg/torture/pr42110.C: new file.

        2009-12-07  Jakub Jelinek  <jakub@redhat.com>

        PR debug/42244
        * gcc.dg/debug/pr42244.c: New test.

        2009-12-04  David Daney  <ddaney@caviumnetworks.com>

        PR rtl-optimization/42164
        * gcc.c-torture/compile/pr42164.c: New test.

        2009-12-03  Jason Merrill  <jason@redhat.com>

        PR c++/41611
        * g++.dg/abi/guard2.C: New.

        2009-12-03  Dodji Seketeli  <dodji@redhat.com>

        PR c++/42217
        * g++.dg/other/bitfield4.C: New test.

        2009-12-03  Jakub Jelinek  <jakub@redhat.com>

        PR c++/42256
        * g++.dg/inherit/thunk11.C: New test.
        * g++.dg/inherit/thunk11.h: New file.
        * g++.dg/inherit/thunk11-aux.cc: New file.

        2009-12-01  Martin Jambor  <mjambor@suse.cz>

        PR tree-optimization/42237
        * gcc.c-torture/compile/pr42237.c: New test.

        2009-12-01  Paolo Carlini  <paolo.carlini@oracle.com>

        PR c++/42057
        * g++.dg/parse/crash54.C: New.

        2009-11-30  Martin Jambor  <mjambor@suse.cz>

        PR middle-end/42196
        * gcc.c-torture/compile/pr42196-1.c: New test.
        * gcc.c-torture/compile/pr42196-2.c: New test.
        * gcc.c-torture/compile/pr42196-3.c: New test.

        2009-11-30  Dodji Seketeli  <dodji@redhat.com>

        PR c++/42069
        * g++.dg/template/typedef23.C: New test.

        2009-11-29  H.J. Lu  <hongjiu.lu@intel.com>

        PR tree-optimization/41961
        * g++.dg/tree-ssa/pr41961.C: New.

        2009-11-29  Ira Rosen  <irar@il.ibm.com>

        PR tree-optimization/42193
        * gcc.dg/vect/pr42193.c: New test.

        2009-11-28  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/42183
        * g++.dg/torture/pr42183.C: New testcase.

        2009-11-27  Martin Jambor  <mjambor@suse.cz>

        PR middle-end/42006
        * gcc.c-torture/execute/pr42006.c: New test.

        2009-11-27  Michael Matz  <matz@suse.de>

        PR rtl-optimization/42084
        * gcc.dg/pr42084.c: New test.

        2009-11-27  Michael Matz  <matz@suse.de>

        PR c++/41906
        * g++.dg/tree-ssa/pr41906.C: New testcase.

        2009-11-26  Michael Matz  <matz@suse.de>

        PR tree-optimization/41905
        * g++.dg/tree-ssa/pr41905.C: New testcase.

        2009-11-24  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/42142
        * gcc.c-torture/execute/pr42142.c: New testcase.

        2009-11-24  Martin Jambor  <mjambor@suse.cz>

        PR tree-optimization/42154
        * gcc.c-torture/execute/pr42154.c: New test.

        2009-11-21  Martin Jambor  <mjambor@suse.cz>

        PR middle-end/42025
        * gcc.c-torture/compile/pr42025-1.c: New test.
        * gcc.c-torture/compile/pr42025-2.c: New test.

        2009-11-21  Jakub Jelinek  <jakub@redhat.com>

        PR tree-optimization/42078
        * gcc.dg/pr42078.c: New test.

Added:
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/abi/guard2.C
      - copied unchanged from r155170, trunk/gcc/testsuite/g++.dg/abi/guard2.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/inherit/thunk11-aux.cc
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/inherit/thunk11-aux.cc
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/inherit/thunk11.C
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/inherit/thunk11.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/inherit/thunk11.h
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/inherit/thunk11.h
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/opt/dtor2-aux.cc
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/opt/dtor2-aux.cc
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/opt/dtor2.C
      - copied unchanged from r155170, trunk/gcc/testsuite/g++.dg/opt/dtor2.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/opt/dtor2.h
      - copied unchanged from r155170, trunk/gcc/testsuite/g++.dg/opt/dtor2.h
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/other/bitfield4.C
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/other/bitfield4.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/parse/crash54.C
      - copied unchanged from r155172,
trunk/gcc/testsuite/g++.dg/parse/crash54.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/const3.C
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/template/const3.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/typedef23.C
      - copied unchanged from r155181,
trunk/gcc/testsuite/g++.dg/template/typedef23.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/typedef24.C
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/template/typedef24.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/typedef25.C
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/template/typedef25.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/torture/pr42110.C
      - copied unchanged from r155170,
trunk/gcc/testsuite/g++.dg/torture/pr42110.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/torture/pr42183.C
      - copied unchanged from r155181,
trunk/gcc/testsuite/g++.dg/torture/pr42183.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/tree-ssa/pr41905.C
      - copied unchanged from r155182,
trunk/gcc/testsuite/g++.dg/tree-ssa/pr41905.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/tree-ssa/pr41906.C
      - copied unchanged from r155182,
trunk/gcc/testsuite/g++.dg/tree-ssa/pr41906.C
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/tree-ssa/pr41961.C
      - copied unchanged from r155181,
trunk/gcc/testsuite/g++.dg/tree-ssa/pr41961.C
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42025-1.c
      - copied unchanged from r155182,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42025-1.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42025-2.c
      - copied unchanged from r155182,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42025-2.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42164.c
      - copied unchanged from r155170,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42164.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42196-1.c
      - copied unchanged from r155181,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42196-1.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42196-2.c
      - copied unchanged from r155181,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42196-2.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42196-3.c
      - copied unchanged from r155181,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42196-3.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/compile/pr42237.c
      - copied unchanged from r155171,
trunk/gcc/testsuite/gcc.c-torture/compile/pr42237.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/execute/pr42006.c
      - copied unchanged from r155181,
trunk/gcc/testsuite/gcc.c-torture/execute/pr42006.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/execute/pr42142.c
      - copied unchanged from r155182,
trunk/gcc/testsuite/gcc.c-torture/execute/pr42142.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.c-torture/execute/pr42154.c
      - copied unchanged from r155182,
trunk/gcc/testsuite/gcc.c-torture/execute/pr42154.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/debug/pr42244.c
      - copied unchanged from r155170,
trunk/gcc/testsuite/gcc.dg/debug/pr42244.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/pr42078.c
      - copied unchanged from r155182, trunk/gcc/testsuite/gcc.dg/pr42078.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/pr42084.c
      - copied unchanged from r155182, trunk/gcc/testsuite/gcc.dg/pr42084.c
    branches/gcc-4_4-branch/gcc/testsuite/gcc.dg/vect/pr42193.c
      - copied unchanged from r155181,
trunk/gcc/testsuite/gcc.dg/vect/pr42193.c
Modified:
    branches/gcc-4_4-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317

[Bug c++/42317] [4.5 Regression] Issues with comdat virtual dtors

[paolo dot carlini at oracle dot com]

------- Comment #9 from paolo dot carlini at oracle dot com  2009-12-26 11:03 -------
I understand can be closed as fixed now.


-- 

paolo dot carlini at oracle dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42317