https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63650
--- Comment #6 from Richard PALO <richard at netbsd dot org> --- For that matter, the following is sufficient to reproduce the problem, the rest is mostly to simulate the xulrunner environment that is failing to build. --------------->8------------------------------ #ifndef CDECL #define CDECL __attribute__((regparm(0),cdecl)) #endif class A { virtual int CDECL foo( void *nok) = 0; }; class B : public A { int foo(void *nok); /* implicitly virtual */ }; --------------->8------------------------------ I should perhaps mention that this is on SunOS 5.11 (illumos) i386.