Pedantic error on address-of main breaks libjava bootstrap

[Andrew Haley]

Aaron W. LaFramboise wrote:
> 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.)

Please send the command line that led to this.

Thanks,
Andrew.