[Bug target/38643] New: Doesn't hide (visibility-wise) vtables and VTTs on ARM EABI

[Bug target/38643] New: Doesn't hide (visibility-wise) vtables and VTTs on ARM EABI

[tbm at cyrius dot com]

[ Forwarded from http://bugs.debian.org/490173 ]

Mike Hommey <mh@glandium.org> reported the following bug to Debian:

GCC doesn't hide (visibility-wise) vtables and VTTs on ARM (EABI).


The problem can be seen on the following code:
-----8<---------
class A {
public:
  int a;
  virtual int v();
};

int A::v() {
  return 2;
}

class B : public A {
public:
  int b;
};

extern "C" __attribute__((visibility("default"))) int test(void) {
  B *b = new B;
  return b->v();
}
-------->8-------

Build with: g++ -fvisibility=hidden -o test.o -c test.cpp
Take a look at symbols with objdump -x test.o

Relevant part:
00000000 g     O .rodata        0000000c _ZTV1A
00000000  w    O .rodata._ZTV1B 0000000c _ZTV1B

These should be marked .hidden.

Resulting shared library (g++ -shared -fvisibility=hidden -o test.so test.cpp)
exports both _ZTV1A and _ZTV1B symbols as a result of this, which is
unexpected.

Proper result is obtained on other architectures (x86 below):
00000000  w    O .rodata._ZTV1A 0000000c .hidden _ZTV1A
00000000  w    O .rodata._ZTV1B 0000000c .hidden _ZTV1B

Note this may be related to the fact that apparently, ARM doesn't have vtables
in .rodata.

This happens with gcc 4.2, 4.3 and trunk.


-- 
           Summary: Doesn't hide (visibility-wise) vtables and VTTs on ARM
                    EABI
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tbm at cyrius dot com
GCC target triplet: arm-linux-gnueabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38643

[Bug target/38643] Doesn't hide (visibility-wise) vtables and VTTs on ARM EABI

[tbm at cyrius dot com]

------- Comment #1 from tbm at cyrius dot com  2008-12-27 17:15 -------
Forgot to say that this only happens with ARM EABI, not with ARM old ABI.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38643

[Bug target/38643] Doesn't hide (visibility-wise) vtables and VTTs on ARM EABI

[laurent at guerby dot net]

------- Comment #2 from laurent at guerby dot net  2009-01-02 12:13 -------
Confirmed on 4.3.2-1 Debian gnueabi

But it looks like it's fixed on trunk rev 142808
00000000 g     O .rodata        0000000c .hidden _ZTV1A
00000000  w    O .rodata._ZTV1B 0000000c .hidden _ZTV1B


-- 

laurent at guerby dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
      Known to fail|                            |4.3.2
      Known to work|                            |4.4.0
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38643

[Bug target/38643] Doesn't hide (visibility-wise) vtables and VTTs on ARM EABI

[tbm at cyrius dot com]

------- Comment #3 from tbm at cyrius dot com  2009-01-03 14:13 -------
You're right that it works with trunk.  I was wrong when I said it still
shows up with trunk.  However, it's not fixed with 4.3 from SVN, so this
bug should be left open.


-- 

tbm at cyrius dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38643

[Bug target/38643] Doesn't hide (visibility-wise) vtables and VTTs on ARM EABI

[ramana at gcc dot gnu dot org]

------- Comment #4 from ramana at gcc dot gnu dot org  2009-05-15 06:28 -------
Doesn't work on 4.3 branch rev. 147478 .Works fine on trunk.


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-05-15 06:28:38
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38643