http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53398
Bug #: 53398 Summary: feature request: option for overloaded methods order in vtable compatibility with msc Classification: Unclassified Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: enhancement Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: sweetrom...@gmail.com The target of this topic is about mingw and ms compiler incompatibility. GCC places overloaded virtual functions in order they appear in class declaration. In opposite msc reverts them. Assuming we have a dll compiled in msc and such header for using the dll: class A { virutal void overl(void) = 0; virutal void fun1(void) = 0; virutal void overl(int i) = 0; virutal void overl(double d) = 0; virutal void fun2(void) = 0; virutal void overl(char *c) = 0; }; to use it with mingw compiler we need to change it to class A { virutal void overl(char *c) = 0; virutal void fun1(void) = 0; virutal void overl(double d) = 0; virutal void overl(int i) = 0; virutal void fun2(void) = 0; virutal void overl(void) = 0; }; or to portable version, which removes overloading (behave gcc ordering) class A { virutal void overlC(char *c) = 0; virutal void fun1(void) = 0; virutal void overlD(double d) = 0; virutal void overlI(int i) = 0; virutal void fun2(void) = 0; virutal void overlV(void) = 0; }; It would be nice to have some option to just say the compiler to use different order. We could have an option added to a compiler like -fvisibility-ms-compat or -fabi-version=n. Or maybe better by something like pragma pack push, so we can do: #pragma vtorder(push, reverted) #include "dll_header.h" #pragma vtorder(pop)