[Bug c++/50270] New: Some symbols are exported even when -fvisibility=hidden is used

almeidaraf at gmail dot com gcc-bugzilla@gcc.gnu.org
Thu Sep 1 19:54:00 GMT 2011


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50270

             Bug #: 50270
           Summary: Some symbols are exported even when
                    -fvisibility=hidden is used
    Classification: Unclassified
           Product: gcc
           Version: 4.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: almeidaraf@gmail.com


Created attachment 25169
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25169
Output of gcc -E -fvisibility=hidden -fvisibility-inlines-hidden -fPIC -Wall
-Wextra -shared foo.c

When I compile foo.cc with the following command:

    $gcc -fvisibility=hidden -fvisibility-inlines-hidden -fPIC -Wall -Wextra
-shared foo.cc -olibfoo.so

There are still quite a few exported symbols. For instance:
   
_ZNSt6vectorI3FooSaIS0_EE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPS0_S2_EERKS0_

which should not be exported. This is what objdump -T displays:

    00000000000023b2  w   DF .text  00000000000002d2  Base       
_ZNSt6vectorI3FooSaIS0_EE13_M_insert_auxEN9__gnu_cxx17__normal_iteratorIPS0_S2_EERKS0_

In readelf -s it comes out in .dynsym as:

    62: 00000000000023b2   722 FUNC    WEAK   DEFAULT   12
_ZNSt6vectorI3FooSaIS0_EE

To my understanding my shared library shouldn't be exporting any symbols.

$gcc -v
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.4.3-4ubuntu5'
--with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--enable-multiarch --enable-linker-build-id --with-system-zlib
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.4 --program-suffix=-4.4 --enable-nls
--enable-clocale=gnu --enable-libstdcxx-debug --enable-plugin --enable-objc-gc
--disable-werror --with-arch-32=i486 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)

$lsb_release -a
No LSB modules are available.
Distributor ID:    Ubuntu
Description:    Ubuntu 10.04.3 LTS
Release:    10.04
Codename:    lucid

I could not add more than one attachment, so I added gcc -E output as an
attachment and foo.cc code goes here:

#include <vector>

class __attribute__ ((visibility ("hidden"))) Foo {
 public:
  int m() {
    return 0;
  }
};


int main(void) {
  std::vector<Foo> v;
  v.push_back(Foo());
  return 0;
}



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