------- Comment #7 from mattias at virtutech dot se 2009-03-20 17:16 ------- The proposed patch works for plain C code, but also affects C++. Since libstdc++ contains code that returns aggregates or calls code that does, -mms-aggregate-return will make the generated code incompatible with the C++ library. This makes it impossible to write C++ code that links (as a DLL) to code compiled with Microsoft or Intel compilers, even if the interface is in plain C.
We are exactly in this situation. We will have to build libstdc++ with -mms-aggregate-return, but that option would then become mandatory for all C++ code. Things would be easier if the option were on by default - we can do this for our build locally, of course, but we'd rather not diverge too much from the standard behaviour. An alternative would be to make the option only affect C (including extern "C" in C++), as other languages are not subject to compatibility with MS compilers. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36834
