Reminder: Illegal Package-Private Accesses in libgcj

[Bryce McKinlay]

On Nov 4, 2003, at 11:01 AM, Andrew Haley wrote:

> Bryce McKinlay writes:
>>
>> On Nov 4, 2003, at 12:25 AM, Andrew Haley wrote:
>>
>>> Bryce McKinlay writes:
>>>>
>>>> If there are targets that will never support the unwinder (are
>>>> there?), then it might make sense to allow platforms to define some
>>>> platform-specific unwinding functions, but ideally, by far the
>>>> cleanest and most efficient solution is to get the libgcc DWARF2
>>>> unwinder working.
>>>
>>> Efficient?  I don't think so.  The glibc backtrace() function simply
>>> walks a linked list, and there's no more efficient way to do it than
>>> that.  The DWARF unwinder is a couple of orders of magnitude slower.
>>
>> OK, but how do you get the java.lang.Class object from the IP value
>> which backtrace() gives you?
>
> We look it up in a hash table.  We sure don't call external programs!

But you can't map a backtrace IP directly to a Class in the hashtable, 
you have to find the function entry point first. I don't know of a way 
to do that apart from using _Unwind_FindEnclosingFunction.

Regards

Bryce.