Somtimes breakpoints dont get hit.

[michaelc37]

in my case it was not monodevelop was not hitting breakpoints if they were in a constructor (however it works with normal/base gdb plugin).

i tracked it down to DGdbBacktrace.CreateVarObject when called from GdbBacktrace.GetParameters. It might need try catch around the "return Variables.EvaluateVariable (exp);" similarly to the base GdbBacktrace.CreateVarObject ..

either of these worked for me, not sure which is better
1)
try {
return Variables.EvaluateVariable (exp);
} catch {
return base.CreateVarObject (exp);
}

2.      try {
            return Variables.EvaluateVariable (exp);
        } catch {
            return ObjectValue.CreateUnknown (exp);
        }
   

I understand that this does not help fix the true problem of why an exception is occuring in the first place, but at least it does not prevent the breakpoints from being hit.

callstack when i noticed this behavior:
MonoDevelop.Debugger.Gdb.D.DGdbBacktrace.CreateVarObject (exp="this")
MonoDevelop.Debugger.Gdb.GdbBacktrace.GetParameters
MonoDevelop.Debugger.Gdb.D.DGdbBacktrace.GetParameters
Mono.Debugging.Client.StackFrame.GetParameters
MonoDevelop.Debugger.StackTracePad.EvaluateMethodName
MonoDevelop.Debugger.StackTracePad.Update
MonoDevelop.Debugger.StackTracePad.UpdateDisplay

[aBothe]

Hi Michael!

First off - stepping through ctors does work for me(tm) - but well, there might be some D magic circumstances in which my stuff doesn't work.

Could you step to the Variables.EvaluateVariable('this') method and show me the ScopedBlock&Statement of the Resolution ctxt?

[michaelc37]

i tried to capture some screenshots..
it seems after "var typeName = Memory.ReadDynamicObjectTypeString (exp);" is executed,
typeName is an empty string, which later causes "DParser.ParseBasicType (typeName, out optToken);" to return a null object, then StripTemplateTypes fails when it tries to deference that object.

http://i.imgur.com/VrinDaD.png
http://i.imgur.com/EY4tFFl.png

[aBothe]

Okay, but why should it fail to read the object type? Could you research some more about this?

Basically I indeed should null-check the typeName, but this also indeed doesn't solve the main problem..so well, gonna commit a fix

[michaelc37]

Ok, i'll try to dig into why Memory.ReadDynamicObjectTypeString returns that empty string.

[aBothe]

sure :D

[michaelc37]

as screenshot shows it seems gdb fails on the data-read-memory-bytes, however the other arguments seem complex.. is that normal?

http://i.imgur.com/dDOZdpY.png

also, not sure why in that scenario the currenline is on "return lastResult", i tried it a few more times it ends up in "throw new GdbException..."

[aBothe]

What OS architecture do you've got? I guess 64 bit, right?

Yes, those read mem commands are complex indeed - pure pointer manipulation and casting stuff..but it works in the most places :)

[aBothe]

Anyway, why is there a such weird exception message? Which integer is meant to be larger than 8 bytes? Is gdb only trying to read one integer that is 16 bytes large?

[Dato0011-zz]

I have the same exact problem. Is there any way to fix this problem. I really like MonoDevelop and really don't want to switch to DDT :(