Re: Fix vector C++11 allocator bug

[Jonathan Wakely <jwakely dot gcc at gmail dot com>]

On 7 March 2013 21:28, François Dumont wrote:
> Hi
>
>     While working on unordered containers C++11 allocator integration I used
> forward_list tests you have done Jon. It reported some problems that should
> have been seen on forward_list or vector allocator tests too if those tests
> were indeed manipulating memory. But there weren't because no element was
> ever injected in the containers.
>
>     So I have started injecting elements and the propagating_allocator issue
> shown up like in my unordered container tests. The problem is that there is
> an assertion in the allocator to check that memory is returned to the
> correct allocator instance thanks to the personality. But when forward_list
> or vector instances with non propagating allocators are swapped personnality
> is not swapped and the issue. So I have introduced a bool template parameter
> to disable all assertions regarding personality so that the allocator can
> still be used to check that personality hasn't been exchanged.
>
>     Additional, making the vector tests more functional revealed a bug in
> vector implementation.

Good catch, thanks.

Instead of making uneq_allocator more complicated how about just doing
std::swap(v1, v2) again after the tests comparing get_personality?

So we don't touch uneq_allocator, keep the operator== overloads in the
test, and the diff for forward_list/allocator/swap.cc just becomes

diff --git a/libstdc++-v3/testsuite/23_containers/forward_list/allocator/swap.cc
b/libstdc++-v3/testsuite/23_containers/forward_list/allocator/swap.cc
index a2e70b7..b5b4480 100644
--- a/libstdc++-v3/testsuite/23_containers/forward_list/allocator/swap.cc
+++ b/libstdc++-v3/testsuite/23_containers/forward_list/allocator/swap.cc
@@ -48,10 +48,14 @@ void test01()
   typedef propagating_allocator<T, false> alloc_type;
   typedef std::forward_list<T, alloc_type> test_type;
   test_type v1(alloc_type(1));
+  v1.push_front(T());
   test_type v2(alloc_type(2));
+  v2.push_front(T());
   std::swap(v1, v2);
   VERIFY(1 == v1.get_allocator().get_personality());
   VERIFY(2 == v2.get_allocator().get_personality());
+  // swap back so assertions in uneq_allocator::deallocate don't fail
+  std::swap(v1, v2);
 }

 void test02()
@@ -60,7 +64,9 @@ void test02()
   typedef propagating_allocator<T, true> alloc_type;
   typedef std::forward_list<T, alloc_type> test_type;
   test_type v1(alloc_type(1));
+  v1.push_front(T());
   test_type v2(alloc_type(2));
+  v2.push_front(T());
   std::swap(v1, v2);
   VERIFY(2 == v1.get_allocator().get_personality());
   VERIFY(1 == v2.get_allocator().get_personality());


That fixes the forward_list failure.  I'm just testing teh vector parts now ...