[Bug c++/54883] New: Name mangling of types in an unnamed namespace

[Bug c++/54883] New: Name mangling of types in an unnamed namespace

[wolfgang.roehrl@gi-de.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

             Bug #: 54883
           Summary: Name mangling of types in an unnamed namespace
    Classification: Unclassified
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: wolfgang.roehrl@gi-de.com


Hi all,

I would like to post a bug report for the GNU C/C++ compiler
version 4.5.2 (powerpc-rtems4.11).

We use the compiler to generate code for a PowerPC processor.

The compiler is invoked with the following options:

ccppc -c -x c++ -ansi -Wall -Werror -g -mcpu=8540 -fverbose-asm -mbig
      -mfloat-gprs=double -mspe -mabi=spe -meabi -msdata -fno-common
      -mmultiple -mno-string -misel -mstrict-align -fgcse-sm
      -fno-rename-registers -fno-section-anchors -G 8 -Os
      -fno-exceptions -fno-rtti
      -I<some include paths>
      -D<some #define's>
      TEST1.CPP -oTEST1.O


// file TEST1.CPP

namespace { enum E { E1, E2, E3 }; }   // unnamed namespace

int func (E e) { return e; }


// file TEST2.CPP

namespace { enum E { E1, E2, E3 }; }   // unnamed namespace

int func (E e) { return e; }


The compiler translates in both files the name of func() to the decorated
name "_Z4funcN12_GLOBAL__N_11EE". This is wrong because the enums E are
different types due to the unnamed namespaces.

In our system the functions func() are template functions und therefore the
linker merges them into one function in the object file which leads to a wrong
program behavior.

BTW, our compiler version 4.3.2 shows this error too, whereas our compiler
version 3.3 seems to perform a correct name mangling.

With kind regards
W. Roehrl

[Bug c++/54883] Name mangling of types in an unnamed namespace

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal

[Bug c++/54883] Name mangling of types in an unnamed namespace

[sebastian.huber@embedded-brains.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

Sebastian Huber <sebastian.huber@embedded-brains.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sebastian.huber@embedded-br
                   |                            |ains.de

--- Comment #1 from Sebastian Huber <sebastian.huber@embedded-brains.de> 2012-10-26 13:49:23 UTC ---
This bug is also present in x86-64 in GCC 4.6, 4.7, and 4.8.

echo "namespace { enum E { E1 }; } void f(E e) { }" | tee a.c b.c > /dev/null
g++ -c a.c -o a.o
g++ -c b.c -o b.o
objdump --syms a.o

a.o:     file format elf64-x86-64

SYMBOL TABLE:
0000000000000000 l    df *ABS*  0000000000000000 a.c
0000000000000000 l    d  .text  0000000000000000 .text
0000000000000000 l    d  .data  0000000000000000 .data
0000000000000000 l    d  .bss   0000000000000000 .bss
0000000000000000 l    d  .comment.SUSE.OPTs     0000000000000000
.comment.SUSE.OPTs
0000000000000000 l    d  .note.GNU-stack        0000000000000000
.note.GNU-stack
0000000000000000 l    d  .eh_frame      0000000000000000 .eh_frame
0000000000000000 l    d  .comment       0000000000000000 .comment
0000000000000000 g     F .text  0000000000000009 _Z1fN12_GLOBAL__N_11EE


objdump --syms b.o

b.o:     file format elf64-x86-64

SYMBOL TABLE:
0000000000000000 l    df *ABS*  0000000000000000 b.c
0000000000000000 l    d  .text  0000000000000000 .text
0000000000000000 l    d  .data  0000000000000000 .data
0000000000000000 l    d  .bss   0000000000000000 .bss
0000000000000000 l    d  .comment.SUSE.OPTs     0000000000000000
.comment.SUSE.OPTs
0000000000000000 l    d  .note.GNU-stack        0000000000000000
.note.GNU-stack
0000000000000000 l    d  .eh_frame      0000000000000000 .eh_frame
0000000000000000 l    d  .comment       0000000000000000 .comment
0000000000000000 g     F .text  0000000000000009 _Z1fN12_GLOBAL__N_11EE

[Bug c++/54883] Name mangling of types in an unnamed namespace

[sebastian.huber@embedded-brains.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

--- Comment #2 from Sebastian Huber <sebastian.huber@embedded-brains.de> 2012-10-30 14:16:05 UTC ---
Known to work GCC 4.0.4, 4.1.2, and 4.2.4:

echo "namespace { enum E { E1 }; } void f(E e) { }" | tee a.c b.c
namespace { enum E { E1 }; } void f(E e) { }
/scratch/install-gcc-4.2.4/bin/g++ -c a.c -o a.o
/scratch/install-gcc-4.2.4/bin/g++ -c b.c -o b.o
nm a.o b.o

a.o:
0000000000000000 T _Z1fN32_GLOBAL__N_a.c_00000000_287815161EE
                 U __gxx_personality_v0

b.o:
0000000000000000 T _Z1fN32_GLOBAL__N_b.c_00000000_BE213B141EE
                 U __gxx_personality_v0

Known to fail 4.3.6, 4.4.7, 4.5.4, 4.6.3, 4.7.2, and 4.8.0.

Is this a bug or a feature?

In the GCC 4.3 release notes there is nothing about namespaces
(http://gcc.gnu.org/gcc-4.3/changes.html).

It would be nice if someone can point out the future direction of this PR, e.g.
NEW or RESOLVED/WONTFIX.

[Bug c++/54883] [4.6/4.7/4.8 Regression] Name mangling of types in an unnamed namespace

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ABI
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-12-09
      Known to work|                            |4.2.4
   Target Milestone|---                         |4.6.4
            Summary|Name mangling of types in   |[4.6/4.7/4.8 Regression]
                   |an unnamed namespace        |Name mangling of types in
                   |                            |an unnamed namespace
     Ever Confirmed|0                           |1

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-12-09 02:50:00 UTC ---
Confirmed.
Simple linktime testcase:
echo "namespace { enum E { E1 }; } void f(E e) { }" | tee a.c b.c > /dev/null
echo "int main(void){}"> c.c
g++ a.c b.c c.c

[Bug c++/54883] [4.6/4.7/4.8 Regression] Name mangling of types in an unnamed namespace

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |jason at gcc dot gnu.org
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |

[Bug c++/54883] [4.6/4.7/4.8 Regression] Name mangling of types in an unnamed namespace

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2012-12-11 22:46:16 UTC ---
Author: jason
Date: Tue Dec 11 22:46:08 2012
New Revision: 194430

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=194430
Log:
    PR c++/54883
    * decl2.c (min_vis_r): Handle anon visibility for enums.

Added:
    trunk/gcc/testsuite/g++.dg/abi/anon1.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl2.c

[Bug c++/54883] [4.6/4.7/4.8 Regression] Name mangling of types in an unnamed namespace

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> 2012-12-11 22:46:51 UTC ---
Author: jason
Date: Tue Dec 11 22:46:37 2012
New Revision: 194432

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=194432
Log:
    PR c++/54883
    * decl2.c (min_vis_r): Handle anon visibility for enums.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/g++.dg/abi/anon1.C
Modified:
    branches/gcc-4_6-branch/gcc/cp/ChangeLog
    branches/gcc-4_6-branch/gcc/cp/decl2.c

[Bug c++/54883] [4.6/4.7/4.8 Regression] Name mangling of types in an unnamed namespace

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> 2012-12-11 22:46:29 UTC ---
Author: jason
Date: Tue Dec 11 22:46:22 2012
New Revision: 194431

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=194431
Log:
    PR c++/54883
    * decl2.c (min_vis_r): Handle anon visibility for enums.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/g++.dg/abi/anon1.C
Modified:
    branches/gcc-4_7-branch/gcc/cp/ChangeLog
    branches/gcc-4_7-branch/gcc/cp/decl2.c

[Bug c++/54883] [4.6/4.7/4.8 Regression] Name mangling of types in an unnamed namespace

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54883

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

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

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> 2012-12-11 22:47:52 UTC ---
Fixed for 4.6.4, 4.7.3 and 4.8.