is log variable possible be null ?I've double checked that but still confused
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I'm having an error on my Job when I do adding of BigDecimal on my tMap.
this is my code.
Var.var1.add(Var.var2).add(Var.var3).add(Var.var4)
all of my variables are BigDecimal.
my error is 'NullPointerException'.
I already checked data on my Database and all have values. I also checked Nullable on my tMap.
Thank You.
This error is happening because you are calling uninitialized variables.
Maybe you are writing this sentence inside the Var box in the tMap?
If not, are you able to output all the Var.varN BigDecimals independently without errors?
I've written some code that dumps all ivars of a class into a dictionary in Objective C. This uses valueForKey: to get the data from the class. Sometimes, KVC throws an internal exception that is also captured properly - but this disrupts lldb's feature and all I get is:
error: Execution was interrupted, reason: internal ObjC exception breakpoint(-3)..
The process has been returned to the state before expression evaluation.
There are no breakpoints set. I even tried with -itrue -ufalse as expression options, but it doesn't make a difference. This totally defeats for what I want to use lldb for, and it seems like such a tiny issue. How can I bring clang to simply ignore if there are internal, captured ObjC exceptions while calling a method?
I tried this both from within Xcode, and directly via calling clang from the terminal and connecting to a remote debug server - no difference.
I ran into the same issue. My solution was to wrap a try/catch around it (I only use this code for debugging). See: DALIntrospection.m line #848
NSDictionary *DALPropertyNamesAndValuesMemoryAddressesForObject(NSObject *instance)
Or, if you're running on iOS 7, the private instance method _ivarDescription will print all the ivars for you (similar instance methods are _methodDescription and _shortMethodDescription).
I met the same problem.
My solution is simply alloc init the property before assigning it to the value which caused the crash.
Myself and coworkers ran into this today, and we eventually found a workaround using lldb's python API. The manual way is to run script, and enter:
options = lldb.SBExpressionOptions()
options.SetTrapExceptions(False)
print lldb.frame.EvaluateExpression('ThisThrowsAndCatches()', options).value
This could be packaged into its own command via command script add.
error: Execution was interrupted, reason: internal ObjC exception breakpoint(-3).. The process has been returned to the state before expression evaluation.
Note that lldb specifically points to the internal breakpoint -3 that caused the interruption.
To see the list of all internal breakpoints, run:
(lldb) breakpoint list --internal
...
Kind: ObjC exception
-3: Exception breakpoint (catch: off throw: on) using: name = 'objc_exception_throw', module = libobjc.A.dylib, locations = 1
-3.1: where = libobjc.A.dylib`objc_exception_throw, address = 0x00007ff81bd27be3, unresolved, hit count = 4
Internal breakpoints can be disabled like regular ones:
(lldb) breakpoint disable -3
1 breakpoints disabled.
In case lldb continues getting interrupted you might also need to disable the conditions of the breakpoint:
(lldb) breakpoint disable -3.*
1 breakpoints disabled.
In my particular case there were multiple exception breakpoints I had to disable before I finally got the expected result:
(lldb) breakpoint disable -4 -4.* -5 -5.*
6 breakpoints disabled.
I'm trying to integrate CocoaLumberjack into a project that I inherited. I've seen it work fine in the past with other projects, but for some reason, I'm getting several errors in CocoaLumberjack's code. Examples include:
Suddenly I'm getting "Assigning to 'void *' from incompatible type 'const char [1]'" compile errors on struct properties when passing in a C string.
I'm getting warnings on C arrays of C strings saying "Conversion from string literal to 'char *' is depreciated.
"class" has suddenly become a keyword (the lowercase version)
Has anyone ever seen anything similar to this? The build settings on the project have definitely been changed a bit, but I'm not sure what was done.
Any chance you're accidentally compiling the code as C++/Obj-C++? The third point there with class becoming a keyword makes that sound plausible.
i have had this happen in vs, where the errors show up from newest to oldest as the compiler runs through the source code.Try to if your doing something like this always remember to trace to the first error and go from there. I have had some pretty crazy results by putting a semicolon (;) after an include statment
ie
<string>;
<vector>;
will throw a crazy set of errors if it is in the wrong place.
I'm getting the following analyzer warning on this line...
if ([datStartDate compare:now] == NSOrderedDescending) {
Receiver in message expression is an uninitialized value
The line of code occurs in the middle of an IBAction.
What am I doing wrong?
If you expand the disclosure triangle next to the error (in the error navigator on the left side), it'll show you the exact code path that leads to a situation where the value is not initialized.
You may think "But, analyzer, really, that can never happen.". While that may be true, you are creating an assumption in your code that may not hold true in the future due to bug or intentional change. That increases the fragility of your codebase and will lead to maintenance headaches.
Fix the code such that it is explicit and remove the assumption.
There is at least one code path that can lead to this line with datStartDate still being uninitialized. That means you have never assigned an object to datStartDate, not even nil.
Today I discovered that something I had assumed about VB.NET for many years was not true (worrying!). I assumed that a variable declared within a loop had a lifetime of the iteration it was declared in, but in fact it seems it has a lifetime of the whole procedure.
For example:
For i As Integer = 0 To 1
Dim var1 As Boolean
Console.WriteLine(var1.ToString())
var1 = True
Console.WriteLine(var1.ToString())
Next
Console.ReadKey()
I had assumed an output of False, True, False, True but instead it is actually False, True, True, True.
In C# the equivalent code would not compile as you would get a compile time error of Error "Use of unassigned local variable 'var1'".
I realise there are many ways to fix this and that best practice would be to declare the variable outside of the loop and reset it at the beginning of every loop through.
I find this behaviour so counter-intuitive to me that I would like at least a compile time warning in VB.NET when/if I do this. (I could also then set this on any projects I already have and get warning that would allow me to check that my assumptions aren't causing errors).
Does anyone know how/if I can get this to generate a compile time warning in VB.NET? Am I the only one that finds this counter-intuitive?
We'll have to work on fixing your intuition because getting an error out of the compiler is not an option. It is partially implemented, you can get this warning:
error BC42104: Variable 'mumble' is used before it has been assigned a value. A null reference exception could result at runtime.
And elevate it from a warning to an error with Project + Properties, Compile tab. However, as the warning message indicates, this is only supported for reference type references, it won't budge for a variable of a value type.
Okay, intuition. If the runtime would implement your desired behavior then it would have to allocate a new variable for each iteration of the loop. Which implies that the number of local variables is bounded only by the number of iterations. This is very wasteful and a very easy trigger for StackOverflowException. The JIT compiler doesn't do this, it re-uses the variable. This happens in C# as well, minus the option of letting you not initialize the value explicitly of course.
Fwiw: I very much agree with you that this is unhelpful behavior. You'll probably find receptive ears at connect.microsoft.com, post your feature request there and the VB.NET team will see it. There has been strong backing from customers as well as within MSFT to make VB.NET and C# feature comparable. If you post a link to your feedback report then I'll be happy to vote it up.