Check whether exceptions are caught

Check whether exceptions are caught

The debugger can now determine whether an exemption will be caught or not.
Committed: https://code.google.com/p/dart/source/detail?r=17167

[hausner, 2013-01-16 20:53:23]

Regis, can you check whether I am using Type and type checks correctly? Thank
you.

[regis, 2013-01-16 21:06:36]

LGTM with comments

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc
File runtime/vm/debugger.cc (right):

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc#new...
runtime/vm/debugger.cc:420: if (type.IsMalformed()) continue;
If the type is malformed, the test at run time will always throw a TypeError. In
other words, this frame handles the exception, even so briefly. Is 'continue'
correct?

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc#new...
runtime/vm/debugger.cc:421: if (exc_obj.IsInstanceOf(type, no_instantiator,
NULL)) {
How about a comment indicating you may get a false positive without
instantiator?
Actually, I see in the parser that you filter out uninstantiated types. Maybe
you could assert that here or write a comment that it is the case.

[srdjan, 2013-01-16 21:12:16]

lgtm

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc
File runtime/vm/debugger.cc (right):

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc#new...
runtime/vm/debugger.cc:415: intptr_t num_types = handled_types.Length();
const

[hausner, 2013-01-16 22:07:25]

Thank you.

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc
File runtime/vm/debugger.cc (right):

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc#new...
runtime/vm/debugger.cc:415: intptr_t num_types = handled_types.Length();
On 2013/01/16 21:12:16, srdjan wrote:
> const

Done.

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc#new...
runtime/vm/debugger.cc:420: if (type.IsMalformed()) continue;
On 2013/01/16 21:06:36, regis wrote:
> If the type is malformed, the test at run time will always throw a TypeError.
In
> other words, this frame handles the exception, even so briefly. Is 'continue'
> correct?

I think 'continue' to the next type check is correct. This type check will not
succeed when the Dart catch clause executes it later. The TypeError that will be
thrown is intercepted again by the debugger.

https://codereview.chromium.org/11946020/diff/5001/runtime/vm/debugger.cc#new...
runtime/vm/debugger.cc:421: if (exc_obj.IsInstanceOf(type, no_instantiator,
NULL)) {
On 2013/01/16 21:06:36, regis wrote:
> How about a comment indicating you may get a false positive without
> instantiator?
> Actually, I see in the parser that you filter out uninstantiated types. Maybe
> you could assert that here or write a comment that it is the case.

Done.