[Bug middle-end/64937] New: [5 Regression] compare debug failure with -fsanitize=address

[Bug middle-end/64937] New: [5 Regression] compare debug failure with -fsanitize=address

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

            Bug ID: 64937
           Summary: [5 Regression] compare debug failure with
                    -fsanitize=address
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org

Split-off from PR64935, which shows the same message but is caused by a
different revision.

The attached test case fails for me with
  GCC_COMPARE_DEBUG=yes g++ test.ii -fsanitize=address
with the same message:
  g++: error: test.ii: -fcompare-debug failure (length)

Test case is attachment 34664

Works with current 4.9 branch, fails with today's trunk and also with r220315
(the other PR, PR64935, works with that revision).

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |5.0

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> ---
That's with x86-64-gnu-linux. It already failed with r218247; I currently don't
plan to bisect it further.

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

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

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

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I'll have a look tomorrow.

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-02-05
     Ever confirmed|0                           |1

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r212564.

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

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

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

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I think the problem is that cgraph etc. uses the DECL_ABSTRACT_P flag, which is
set in two different places:
1) in the C++ FE
2) in dwarf2out
In the latter, it does:
  was_abstract = DECL_ABSTRACT_P (decl);
  set_decl_abstract_flags (decl, 1);
  dwarf2out_decl (decl);
  if (! was_abstract)
    set_decl_abstract_flags (decl, 0);
So, if the decl was already abstract, it doesn't reset anything.  But,
unfortunately, the set_decl_abstract_flags call is recursive, and not all the
vars in there necessary have DECL_ABSTRACT_P flag already set.
Thus, I think either we should make sure that when the C++ FE sets
DECL_ABSTRACT_P flag on something, it is always set on all the contained decls
too (but how to ensure this if we e.g. further decls are added in various
passes to those functions?), or we should change dwarf2out.c to reset it always
to the previous state, rather than sometimes clearing it (despite it might be
set already before) and sometimes setting it and not clearing it afterwards.
For the latter, guess we could just add a vec<tree> into which we'd push the
decls on which we set the flag, and reversion would be performed by walking the
vector and clearing DECL_ABSTRACT_P flags.  I guess I'll try to implement the
dwarf2out.c change.

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

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

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

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Fri Feb  6 18:26:59 2015
New Revision: 220483

URL: https://gcc.gnu.org/viewcvs?rev=220483&root=gcc&view=rev
Log:
    PR middle-end/64937
    * dwarf2out.c (set_block_abstract_flags, set_decl_abstract_flags):
    Replace setting argument with abstract_vec, always set BLOCK_ABSTRACT
    or DECL_ABSTRACT_P flags to 1 rather than to setting, and if it wasn't
    1 before, push it to abstract_vec.
    (dwarf2out_abstract_function): Adjust caller.  Don't call
    set_decl_abstract_flags second time, instead clear BLOCK_ABSTRACT or
    DECL_ABSTRACT_P flags for all abstract_vec elts.

    * g++.dg/asan/pr64937.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/asan/pr64937.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dwarf2out.c
    trunk/gcc/testsuite/ChangeLog

[Bug middle-end/64937] [5 Regression] compare debug failure with -fsanitize=address

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64937

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> ---
Fixed.