When building libjava stacktrace.o on i386-pc-mingw32, bootstrap fails with:
./sysdep/backtrace.h: In function '_Unwind_Reason_Code
fallback_backtrace(_Unwind_Reason_Code (*)(_Unwind_Context*, void*),
_Jv_UnwindState*)':
./sysdep/backtrace.h:107: error: ISO C++ forbids taking address of function
'::main'
On mingw32, backtrace.h is a symlink or copy to i386/backtrace.h, which
is what has this problem:
if (ctx.meth_addr == (_Jv_uintptr_t)jv_runmain
|| ctx.meth_addr == (_Jv_uintptr_t)_Jv_ThreadStart
|| (ctx.meth_addr - (_Jv_uintptr_t)main) < 16)
break;
The code needs the address of main to stop the unwind. What is the
proper way to suppress this warning? __extension__ doesn't seem to help.
(I'm actually not sure what has changed to cause this warning to start
happening now.)
