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Date: Tue, 27 Jul 2010 07:20:00 -0000
Subject: [Bug libstdc++/45093]  New: Different definitions of _Rb_tree::{erase,_M_destroy_node} between C++98 and C++0x
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Using gold for its --detect-odr-violations:

$ cat test.cc
#include <map>
extern void foo();
int main() {
  foo();
  std::map<int, int> m1;
  m1.insert(std::make_pair(1, 2));
  m1.erase(m1.begin());
}
$ cat test2.cc
#include <map>

void foo() {
  std::map<int, int> m1;
  m1.insert(std::make_pair(1, 2));
  m1.erase(m1.begin());
}
$ ~/opensource/gcc/trunk/install/bin/g++-4.6svn -g -c -std=c++98 test.cc
$ ~/opensource/gcc/trunk/install/bin/g++-4.6svn -g -c -std=c++0x test2.cc
$ ~/opensource/gcc/trunk/install/bin/g++-4.6svn -g -std=c++0x test2.o test.o -o
test -Wl,--detect-odr-violations
.../gcc/trunk/install/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/ld:
error: while linking test: symbol 'std::_Rb_tree<int, std::pair<int const,
int>, std::_Select1st<std::pair<int const, int> >, std::less<int>,
std::allocator<std::pair<int const, int> >
>::_M_destroy_node(std::_Rb_tree_node<std::pair<int const, int> >*)' defined in
multiple places (possible ODR violation):
 
.../gcc/trunk/install/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.6.0/../../../../include/c++/4.6.0/bits/stl_tree.h:385
from test.o
 
.../gcc/trunk/install/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.6.0/../../../../include/c++/4.6.0/bits/stl_tree.h:410
from test2.o
.../gcc/trunk/install/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/ld:
error: while linking test: symbol 'std::_Rb_tree<int, std::pair<int const,
int>, std::_Select1st<std::pair<int const, int> >, std::less<int>,
std::allocator<std::pair<int const, int> >
>::erase(std::_Rb_tree_iterator<std::pair<int const, int> >)' defined in
multiple places (possible ODR violation):
 
.../gcc/trunk/install/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.6.0/../../../../include/c++/4.6.0/bits/stl_tree.h:1362
from test2.o
 
.../gcc/trunk/install/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.6.0/../../../../include/c++/4.6.0/bits/stl_tree.h:1398
from test.o
collect2: ld returned 1 exit status
$


_M_destroy_node() appears to only differ in whether some fields with trivial
destructors get destroyed, but erase() is defined with different return types
between the two versions.

So, two questions: Are -std=c++98 and -std=c++0x supposed to be
binary-compatible?
Would you accept a patch to unify the two definitions?


-- 
           Summary: Different definitions of
                    _Rb_tree::{erase,_M_destroy_node} between C++98 and
                    C++0x
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jyasskin at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45093