[cxx-abi-dev] Mangling of calling convention attributes

[Jason Merrill]

ia32 targets support a variety of calling conventions, which correspond 
to various attributes (cdecl, stdcall, regparm, etc.).  Currently these 
are not represented in mangling, which leads to problems with template 
instantiation; I'm thinking about starting to treat them as vendor 
qualifiers, so given

extern "C" void abort();
template <typename F, typename T>
void IndirectExternCall(F f, T t1, T t2) {
   typedef F (*WrapF)(F);
   f (t1, t2);
}

__attribute__((regparm(3), stdcall))
void regparm_func (int i, int j)
{
   if (i != 24 || j != 42)
     abort();
}

void normal_func (int i, int j)
{
   if (i != 24 || j != 42)
     abort();
}

int main()
{
   IndirectExternCall (regparm_func, 24, 42);
   IndirectExternCall (normal_func, 24, 42);
}

the two instantiations of IndirectExternCall would be mangled 
differently.  Currently my prototype mangles stdcall as U7stdcall and 
regparm(3) as U11regparmLi3E, i.e. mangling the attribute argument like 
a template argument.

Any thoughts?

Jason