[Bug debug/55257] New: [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[Bug debug/55257] New: [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

             Bug #: 55257
           Summary: [4.8 Regression]:
                    g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler
                    thunk.C:30
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: wrong-debug
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hp@gcc.gnu.org
                CC: jakub@gcc.gnu.org
              Host: x86_64-unknown-linux-gnu
            Target: cris-axis-elf


Created attachment 28649
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28649
non-virtual-thunk.s

This test previously passed, now it fails.
A patch in the revision range (last_known_working:first_known_failing)
193333:193342 exposed or caused this regression.  Since then it fails as
follows:

Running /tmp/hpautotest-gcc0/gcc/gcc/testsuite/g++.dg/debug/dwarf2/dwarf2.exp
...
FAIL: g++.dg/debug/dwarf2/non-virtual-thunk.C -std=gnu++98  scan-assembler
thunk.C:30
FAIL: g++.dg/debug/dwarf2/non-virtual-thunk.C -std=gnu++11  scan-assembler
thunk.C:30

No extra clue in g++.log.
Executing on host:
/tmp/hpautotest-gcc0/cris-elf/gccobj/gcc/testsuite/g++/../../g++
-B/tmp/hpautotest-gcc0/cris-elf/gccobj/gcc/testsuite/g++/../../
/tmp/hpautotest-gcc0/gcc/gcc/testsuite/g++.dg/debug/dwarf2/non-virtual-thunk.C 
-fno-diagnostics-show-caret  -nostdinc++
-I/tmp/hpautotest-gcc0/cris-elf/gccobj/cris-elf/libstdc++-v3/include/cris-elf
-I/tmp/hpautotest-gcc0/cris-elf/gccobj/cris-elf/libstdc++-v3/include
-I/tmp/hpautotest-gcc0/gcc/libstdc++-v3/libsupc++
-I/tmp/hpautotest-gcc0/gcc/libstdc++-v3/include/backward
-I/tmp/hpautotest-gcc0/gcc/libstdc++-v3/testsuite/util -fmessage-length=0
-std=gnu++98 -g2 -dA -ffat-lto-objects  -S   -isystem
/tmp/hpautotest-gcc0/cris-elf/gccobj/cris-elf/./newlib/targ-include -isystem
/tmp/hpautotest-gcc0/gcc/newlib/libc/include  -o non-virtual-thunk.s   
(timeout = 300)
PASS: g++.dg/debug/dwarf2/non-virtual-thunk.C -std=gnu++98 (test for excess
errors)
FAIL: g++.dg/debug/dwarf2/non-virtual-thunk.C -std=gnu++98  scan-assembler
thunk.C:30

(same for -std=gnu++11)

There's no "thunk.C:30" in the assembly file, just lots of:
"<TAB>;#
/tmp/hpautotest-gcc0/gcc/gcc/testsuite/g++.dg/debug/dwarf2/non-virtual-thunk.C:33"

See the attached non-virtual-thunk.s.

Author of suspect patch in revision range CC:ed.

[Bug debug/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-12 07:51:26 UTC ---
If the target doesn't call final_start_function and final_end_function in
output_mi_thunk targhook (or equivalent), it is a target bug.

[Bug debug/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-11-12
         AssignedTo|unassigned at gcc dot       |hp at gcc dot gnu.org
                   |gnu.org                     |
   Target Milestone|---                         |4.8.0
     Ever Confirmed|0                           |1

--- Comment #2 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-11-12 17:08:12 UTC ---
(In reply to comment #1)
> If the target doesn't call final_start_function and final_end_function in
> output_mi_thunk targhook (or equivalent), it is a target bug.

I see.  I either missed this requirement when I implemented those bits for CRIS
or it wasn't a requirement at the time.  BTW, I see several ports are missing
those calls.  I guess in the general case it can't be left to middle-end to
call those functions at the right time, so I'll just update the port and
hopefully the documentation, but no promises.  Assigning the PR to myself while
verifying that this is the cause.

[Bug debug/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-12 17:14:41 UTC ---
It is a requirement if you want proper debug info or unwind info for the thunk,
without that (or without calling the corresponding functions yourself, which is
harder to maintain) you don't get proper debug info.  It can't be called from
the middle end, because some targets need to perform various things before
final_start_function (or perhaps after final_end_function).

[Bug debug/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

--- Comment #4 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-11-12 17:21:57 UTC ---
(In reply to comment #3)
> It can't be called from
> the middle end, because some targets need to perform various things before
> final_start_function (or perhaps after final_end_function).

Yes, that's what I meant, so let's just document the requirement.

[Bug target/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|debug                       |target

--- Comment #5 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-11-13 06:14:18 UTC ---
Patch verified, changing component to target prior to commit.

[Bug target/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

--- Comment #6 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-11-13 06:15:59 UTC ---
Author: hp
Date: Tue Nov 13 06:15:53 2012
New Revision: 193467

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=193467
Log:
    PR target/55257
    * config/cris/cris.c (cris_asm_output_mi_thunk): Call
    final_start_function and final_end_function.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/cris/cris.c

[Bug target/55257] [4.8 Regression]: g++.dg/debug/dwarf2/non-virtual-thunk.C scan-assembler thunk.C:30

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55257

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

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

--- Comment #7 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-11-13 06:39:34 UTC ---
.