[D-runtime] win32 regression in exception handling

[Brad Roberts]

On 1/24/2011 8:00 PM, Brad Roberts wrote:
> Now that the dust of the svn -> git migration has settled some, there's a failure that's stuck with us.  Since this
> druntime change, the win32 dmd test34.d test has failed:
> 
> https://github.com/D-Programming-Language/druntime/commit/559df80b3d9c51272c5804de8df27af75099b977
> 
> http://d.puremagic.com/test-results/test_data.ghtml?dataid=43441
> 
>   Before test 3:
>   object.Error at src\rt\deh.d(631): Access Violation
> 
> I did a test build at the previous commit and the test passes.  So that's definitely the one that introduces the
> problem.  It might well be just exposing a dormant problem, but either way, it stopped working at that point.

Ok.. I finally took some time to dive into this one.  It's failing on a catch (DerivedFromError) situation.

>From test34.d:

class B58
{    long x;
     void set(long i) { writeln("B58::set(long)"); x = i; }
     void set(int i)  { writeln("B58::set(int)"); x = i; }
     long squareIt()  { writeln("B58::squareit()"); return x * x; }
}
class D58 : B58
{
     long square;
     void set(long i) { writeln("D58::set(long)"); B58.set(i); square = x * x; }
     long squareIt()  { writeln("D58::squareit()"); return square; }
}

long foo58(B58 b)
{   int i;
    try
    {
        b.set(3);
    }
    catch (HiddenFuncError o)
    {
        i = 1;
    }
    assert(i == 1);
    return b.squareIt();
}

void test58()
{
    writeln(foo58(new D58));
}

Catching Error derived classes is illegal-ish now, right?  I haven't narrowed it down to exactly where the segv is
coming from (the line number above is the part of the eh mechanism that's constructing the error object in the SEH
receiving code, not the point of the segv.. unless that line of code is segving somehow.

Don, do you have the time to dig a little since you've been all over that part of the code recently?

Thanks,
Brad