Actually, forget that.  I do get stack for shell.  Not sure why I'm not 
getting it in my app.  Looking...

On Monday, October 5, 2015 at 4:49:13 PM UTC-7, Jane Chen wrote:
>
> Thanks.  Any tip in debugging this kind of failures?  I don't seem to get 
> a stack even though I'm using debug build both for v8 and my embedding app.
>
> On Monday, October 5, 2015 at 1:59:46 PM UTC-7, Jakob Kummerow wrote:
>>
>> The whole point of a MaybeLocal is that it *may *(or may not) contain a 
>> value. Calling .ToLocalChecked() on it is unsafe, unless you happen to know 
>> that it can't be empty. shell.cc:416 
>> <https://chromium.googlesource.com/v8/v8/+/master/samples/shell.cc#416> 
>> is doing it wrong. d8.cc:883 
>> <https://chromium.googlesource.com/v8/v8/+/master/src/d8.cc#883> is 
>> doing it right.
>>
>> A callback throwing an exception is the canonical example of a function 
>> that possibly returns no value, in which case its MaybeLocal return value 
>> is empty. The reason we've introduced MaybeLocals is so embedders can be 
>> sure they've covered all the places where they have to check for exceptions 
>> being thrown, since they can't accidentally convert from MaybeLocal to 
>> Local without explicitly checking for emptiness.
>>
>>
>> On Mon, Oct 5, 2015 at 9:25 PM, Jane Chen <[email protected]> wrote:
>>
>>> [jchen@jchen-z620 x64.release]$ ./shell
>>> V8 version 4.7.0 (candidate) [sample shell]
>>> > read();
>>> (shell):1: Bad parameters
>>> read();
>>> ^
>>>
>>> #
>>> # Fatal error in v8::ToLocalChecked
>>> # Empty MaybeLocal.
>>> #
>>>
>>> Illegal instruction (core dumped)
>>>
>>> This is with a build made with either:
>>>
>>> make -j8 x64.debug -werror=no GYPFLAGS="-Dv8_use_external_startup_data=0 
>>> -Dcomponent=shared_library"
>>>
>>> or:
>>>
>>> make -j8 x64.release -werror=no 
>>> GYPFLAGS="-Dv8_use_external_startup_data=0 -Dcomponent=shared_library"
>>>
>>> I see this with my embedding application as well as long as I throw an 
>>> exception from a callback.  Am I missing something or should I use a more 
>>> stable branch?  If so, which branch of v8 works with the above?
>>>
>>> Thanks in advance.
>>>
>>> -- 
>>> -- 
>>> v8-users mailing list
>>> [email protected]
>>> http://groups.google.com/group/v8-users
>>> --- 
>>> You received this message because you are subscribed to the Google 
>>> Groups "v8-users" group.
>>> To unsubscribe from this group and stop receiving emails from it, send 
>>> an email to [email protected].
>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>
>>

-- 
-- 
v8-users mailing list
[email protected]
http://groups.google.com/group/v8-users
--- 
You received this message because you are subscribed to the Google Groups 
"v8-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to