[lldb-dev] OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'

[Greg Clayton via lldb-dev]

If you want to send your fabdbg.py we can try it out and see if we see anything wrong.

> On Sep 19, 2016, at 9:12 AM, Greg Clayton <gclayton at apple.com> wrote:
> 
> Try printing the type of the value you are passing in the line:
> 
>    vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr-8, error)
> 
> print type(vtableAddr)
> print type(vtableAddr-8)
> 
> It seems like it thinks vtableAddr doesn't fit into a lldb::addr_t which is a uint64_t
> 
> 
> 
>> On Sep 16, 2016, at 7:39 PM, Lei Kong via lldb-dev <lldb-dev at lists.llvm.org> wrote:
>> 
>> I tried printing error.descryption, but it didn't work, because when the error happens, it seems ReadPointerFromMemory never returned to my code.
>> 
>> 
>> read from address 0000000001223f68
>> Traceback (most recent call last):
>>  File "<input>", line 1, in <module>
>>  File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 289, in findall
>>    findtypes(pattern,ignorePureVirtualType)
>>  File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 246, in findtypes
>>    if ignorePureVirtualType and has_pure_virtual(vtableAddr, pureVirtualFuncs) :
>>  File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 190, in has_pure_virtual
>>    vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr-8, error)
>>  File "/home/leikong/bin/lldb/lib/python2.7/site-packages/lldb/__init__.py", line 9418, in ReadPointerFromMemory
>>    return _lldb.SBProcess_ReadPointerFromMemory(self, addr, error)
>> OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'
>> 
>> 
>>> Subject: Re: [lldb-dev] OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'
>>> From: jingham at apple.com
>>> Date: Fri, 16 Sep 2016 17:12:24 -0700
>>> CC: lldb-dev at lists.llvm.org
>>> To: leikong at msn.com
>>> 
>>> You passed an error into ReadPointerFromMemory. In the cases where you aren't getting what you expect, what does that error say?
>>> 
>>> Jim
>>> 
>>>> On Sep 16, 2016, at 5:06 PM, Lei Kong via lldb-dev <lldb-dev at lists.llvm.org> wrote:
>>>> 
>>>> I ran into the error in the subject when running a python script with "script myfile.myscript()".
>>>> 
>>>> The value addr_t parameter used is 0x0000000001223f68, the following works fine:
>>>> 
>>>> (lldb) scr
>>>> Python Interactive Interpreter. To exit, type 'quit()', 'exit()' or Ctrl-D.
>>>>>>> e = lldb.SBError()
>>>>>>> ptr = lldb.process.ReadPointerFromMemory(0x0000000001223f68, e)
>>>>>>> print ptr
>>>> 0
>>>>>>> 
>>>> 
>>>> Any suggestion how to further investigate? Thanks.
>>>> 
>>>> myfile.myscript() calls the following function in a loop (iterate through all vtable symbols), which contains the call ReadPointerFromMemory.
>>>> 
>>>> def dump_vtbl(vtableAddr) :
>>>> error = lldb.SBError()
>>>> vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr+8, error)
>>>> if not error.success :
>>>> return False
>>>> print "vtable: [%0.16x, %0.16x)" % (vtableAddr, vtableEndAddr)
>>>> for addr in range(vtableAddr, vtableEndAddr, 8) :
>>>> print "read from address %.016x" % addr
>>>> try:
>>>> funcAddr = lldb.process.ReadPointerFromMemory(addr, error)
>>>> except:
>>>> sys.exc_clear()
>>>> continue
>>>> if not error.success :
>>>> continue
>>>> 
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>>> 
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