Work around GCC PR37804

[mdaniels]

Summary

Using gcc with libc++ is not able to build boost's program_options library.

It looks like this is caused by a bug in gcc[0], and this change attempts to work around a couple cases where it gets hit.

The gcc report also mentions a problem with vector/string but I was not able to reproduce that locally, and believe that specific case was fixed with https://reviews.llvm.org/D7201

[0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37804

[EricWF]

Well that is a shitty GCC bug. Thanks for the workaround.

include/__tree

26

1. This should probably be #if defined(__GNUC__) && !defined(__clang__)
2. Please use the bug URL gcc.gnu.org/PR37804 is the comment instead.

[mdaniels]

Update based on Eric's feedback.

[mdaniels]

Mark done.

[mclow.lists]

I changed the _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS and committed this as revision 351993.

[chandlerc]

Hey Marshall and Michael,

As mentioned in my email to all the lists[1], patches posted to Phabricator before the new license was installed should be confirmed as under the new license before being rebased and applied. Not sure that happened here as the file headers are still the old file headers.

I'll update the file headers anyways, and I think this is fine as Michael is contributing with an @apple.com email address and so all of this is covered by their agreement anyways. But I wanted to mention it in case there are other in-flight patches on Phabricator where this is relevant.

-Chandler

[1]: http://lists.llvm.org/pipermail/llvm-dev/2018-December/128695.html (llvm-dev), http://lists.llvm.org/pipermail/libcxx-dev/2019-January/000140.html (libcxx-dev)

include/__tree

 #include <algorithm>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+#if defined(__GNUC__) /* GCC PR37804 */
+template <class, class, class, class> class _LIBCPP_TYPE_VIS_ONLY map;
+template <class, class, class, class> class _LIBCPP_TYPE_VIS_ONLY multimap;
+template <class, class, class> class _LIBCPP_TYPE_VIS_ONLY set;
+template <class, class, class> class _LIBCPP_TYPE_VIS_ONLY multiset;
+#endif
+
 template <class _Tp, class _Compare, class _Allocator> class __tree;
 template <class _Tp, class _NodePtr, class _DiffType>
     class _LIBCPP_TYPE_VIS_ONLY __tree_iterator;
 template <class _Tp, class _ConstNodePtr, class _DiffType>
     class _LIBCPP_TYPE_VIS_ONLY __tree_const_iterator;
 
 template <class _Pointer> class __tree_end_node;
 template <class _VoidPtr> class __tree_node_base;

test/std/containers/associative/map/gcc_workaround.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// Tests workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37804
+
+#include <map>
+std::map<int,int>::iterator it;
+#include <set>
+using std::set;
+using std::multiset;
+
+int main(void)
+{
+       return 0;
+}

test/std/containers/associative/set/gcc_workaround.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// Tests workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37804
+
+#include <set>
+std::set<int> s;
+#include <map>
+using std::map;
+using std::multimap;
+
+int main(void)
+{
+       return 0;
+}