[libcxx] r309474 - [libc++] Hoist extern template above first use

[Shoaib Meenai via cfe-commits]

Author: smeenai
Date: Fri Jul 28 19:54:41 2017
New Revision: 309474

URL: http://llvm.org/viewvc/llvm-project?rev=309474&view=rev
Log:
[libc++] Hoist extern template above first use

This function template is referenced inside class basic_string as a
friend function. The extern template declaration needs to be above that
friend declaration to actually take effect.

This is important because this function was marked as exported in
r307966, so without the extern template taking effect, it can leak into
other DSOs as a visible symbol.

Modified:
    libcxx/trunk/include/string

Modified: libcxx/trunk/include/string
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/string?rev=309474&r1=309473&r2=309474&view=diff
==============================================================================
--- libcxx/trunk/include/string (original)
+++ libcxx/trunk/include/string Fri Jul 28 19:54:41 2017
@@ -556,6 +556,8 @@ template<class _CharT, class _Traits, cl
 basic_string<_CharT, _Traits, _Allocator>
 operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, _CharT __y);
 
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS string operator+<char, char_traits<char>, allocator<char> >(char const*, string const&))
+
 template <bool>
 class _LIBCPP_TEMPLATE_VIS __basic_string_common
 {
@@ -3999,7 +4001,6 @@ basic_string<_CharT, _Traits, _Allocator
 
 _LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_string<char>)
 _LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_string<wchar_t>)
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS string operator+<char, char_traits<char>, allocator<char> >(char const*, string const&))
 
 #if _LIBCPP_STD_VER > 11 
 // Literal suffixes for basic_string [basic.string.literals]