I may be clearly misunderstanding what you are trying to say here, but my expectation is that given
T *ptr = nullptr; the way to check if "ptr" is a nullptr would be sbvalueForPtr.GetValueAsUnsigned() == 0 given that sbvalueForPtr.GetType().IsPointerType() is true As for the special case of a shared_ptr<>, that is a class that has an instance variable of pointer type. To check for NULL-ness, you're gonna have to retrieve the child. That requires you to have some knowledge of the internals of your standard C++ library. An alternative would be (and I am not sure if that is plugged in at the moment - if not feel free to ask for it, or provide a patch to that effect) to use the recently added ability for synthetic children to provide a numeric value. One could imagine wiring things up so that the shared_ptr<>'s value is the underlying pointer value. Then no child fetching would be required. Sent from my iPhone > On Feb 15, 2015, at 11:23 PM, Spundun Bhatt <spun...@gmail.com> wrote: > > (Using OSX 10.10.1, XCode 6.1.1 6A2008a, lldb-320.4.156, Apple LLVM version > 6.0 (clang-600.0.56) (based on LLVM 3.5svn) ) > > Hi all, > I have just started using LLDB and its Python scripting interface. > > I may have stumbled upon a deep bug related to null pointer treatment. > > http://lldb.llvm.org/scripting.html I tried to follow this scripting tutorial. > > http://pastebin.com/S0RhVG3s This is the output of my interaction with the > lldb and the python script. (I haven't modified any part of the example code > there) > > It seems like `if left_child_ptr.GetValue() == None:` expression (and other > similar expressions) doesn't evaluate to true for null pointers > > I was able to cook up a python check for null pointer: > > def IsNullPtr(ptr): > > ptr_string = str(ptr.GetValue()) > > if re.search('[1-9a-fA-F]', ptr_string): > > return False; > > else: > > return True; > > I discussed this on the irc channel and zturner thought it looked like a bug > and that I should post it here. > > Hope this helps. > Please let me know if there is a standard way to do null pointer check > through the python API. Especially a check for nullptr shared_ptrs. > > _______________________________________________ > lldb-dev mailing list > lldb-dev@cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
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