Breakpoint not working in Lua Glider 1.7.2

duneunit · January 11, 2013, 2:48pm

Hey–

I think I know what is going on. On one of my projects, I started using “middleclass.lua” for a standardized class-creation system. It appears that this fouls up the debugging system in Lua Glider. This is a nice, clean library, so it would suck if Glider and middleclass didn’t play nice with each other.

@nmichaud - are you using the middleclass.lua library by chance?

[import]uid: 10818 topic_id: 34851 reply_id: 138528[/import]

treb.stewart · January 11, 2013, 3:36pm

Breakpoints are working for me in Glider 1.7.2, I’m on the stable release 971 of Corona , tried on both Win 7 machine and Mac (I think 10.6 but might be higher).

Also the variables don’t appear automatically when a breakpoint is hit, but they’re there if you click on Variables in the bottom left.

-Treb [import]uid: 181948 topic_id: 34851 reply_id: 138540[/import]

duneunit · January 11, 2013, 4:03pm

@Treb-

Thanks. I just rolled back to 972. Breakpoints work as expected, but they fail if you use the middleclass.lua library for your class structure definitions. I’m not sure if middleclass is doing something a little hinky, or if Lua Glider just doesn’t know how to handle it’s clever methodology for class creation.

-duneunit [import]uid: 10818 topic_id: 34851 reply_id: 138541[/import]

duneunit · January 11, 2013, 7:47pm

@nmichaud, @M.Y.Developers -

Okay! I figured this out! So I was using middleclass.lua for my class structures, and I “enhanced” it with my own special __tostring and __concat functionality. It worked fine when Glider’s debugger was not activated, but as soon as the debugger kicked in, I think it sent it into a loop. Particularly in regards to how the metatable was set for the class prototype.

THIS CAUSED THE DEBUGGER TO BREAK… Here’s how I was doing it:

created prototype table
when I created an instance, the instance’s metatable __index is set to be the prototype
Next the the prototype’s metatable functions like __tostring, __add, __concat, etc. are defined.
finally, set the prototype’s metatable to be the prototype table

The instance’s metatable and the prototype metatable are the same. This works fine and I think should be fine from a coding standpoint. (Not 100% certain about this cuz I’m just digging into the metatable stuff in more depth now.) But it breaks the debugger.

SO THIS IS WHAT WORKS INSTEAD:

create your prototype table
create a special “instance_mt” metatable for instances of this class
when you create an instance, set the instance’s metatable __index to be the “instance_mt” metatable
Next, create the prototype’s metatable functions like __tostring, __add, __concat, etc. Call that table “proto_mt” or something.
finally, set the prototype’s metatable to be “proto_mt”

I don’t know if there is something wrong with my original method or not. It ran fine. If it’s okay, I’m wondering if Glider can adjust their debugger to allow for such things. If not, well… I would love some insight into my misguided ways.
[import]uid: 10818 topic_id: 34851 reply_id: 138546[/import]

M.Y.developers · January 12, 2013, 1:55pm

@duneunit,

Thanks for investigating this for us! We are looking into the issue and will get an update for you soon.

Regards,
M.Y. Developers
[import]uid: 55057 topic_id: 34851 reply_id: 138635[/import]

M.Y.developers · January 13, 2013, 1:04am

@duneunit,

Although we weren’t able to replicate the bug using the recipe given, the problem probably lies in the __tostring. For future reference there is no such thing as rawget(tab, “__tostring”) so once the __tostring metamethod is set, there is no way to get the unique id (address) back. The workaround we came up with is in the patched CiderDebugger.lua but if anyone needs it:

local rawtostring = function(tab)  
 local mtTostring = tab.\_\_tostring  
 tab.\_\_tostring = nil  
 local result = tostring(tab)  
 tab.\_\_tostring = mtTostring   
 return result  
end

We have patched the CiderDebugger.lua, you can download it here

www.mydevelopersgames.com/site/Cider/v1/v160Beta/test/CiderDebugger.lua

To apply the new patch for windows you just have to navigate to your install directory->luaglider
On our machine the path is:
C:\Program Files (x86)\Lua Glider\luaglider\CiderDebugger.lua
And just replace the old one with the one in the link.

For mac you have to right click->show package contents->resources->luaglider and replace CiderDebugger.lua

In the future, this type of update would occur using the autoupdate but we can’t use that just yet.

Please let us know if this works. If it does not then please provide a code snippet for each of the two scenarios.

Regards,
M.Y. Developers
[import]uid: 55057 topic_id: 34851 reply_id: 138641[/import]

duneunit · January 13, 2013, 11:06am

@MYDevelopers-

Thanks- I really appreciate that you looked into this. So far, the patch doesn’t appear to change anything… BUT, I will try to investigate more in a day or two. The good news is that if I implement my __tostring differently, that seems to eliminate any problems and Glider and all else is working as desired. Because of this, I am starting to think the problem might be predominantly on my end… What really threw me off was having someone else report the identical issue at the same time I encountered it. I’ll update you when I figure it out, tho.

Thanks again!
[import]uid: 10818 topic_id: 34851 reply_id: 138713[/import]

M.Y.developers · January 27, 2013, 3:40pm

@duneunit,

Please let us know if you find anything.

Regards,
M.Y. Developers
[import]uid: 55057 topic_id: 34851 reply_id: 140572[/import]

duneunit · January 29, 2013, 1:29pm

@MYdevs-

I think you guys are clear. I think it was my implementation of __tostring in my metatable for object structure/class definitions. Everything is working fine now on my end, so you can probably call this a user error on my part. Thanks for checkin’ in!

[import]uid: 10818 topic_id: 34851 reply_id: 140817[/import]

M.Y.developers · January 27, 2013, 3:40pm

@duneunit,

Please let us know if you find anything.

Regards,
M.Y. Developers
[import]uid: 55057 topic_id: 34851 reply_id: 140572[/import]

duneunit · January 29, 2013, 1:29pm

@MYdevs-

I think you guys are clear. I think it was my implementation of __tostring in my metatable for object structure/class definitions. Everything is working fine now on my end, so you can probably call this a user error on my part. Thanks for checkin’ in!

[import]uid: 10818 topic_id: 34851 reply_id: 140817[/import]