[lldb-dev] GetSymbolContext(lldb.eSymbolContextEverything)

[Kamenee Arumugam via lldb-dev]

Thanks a lot Greg for your input. I have tried the 2nd option  to parse the
out of image lookup command and it works perfectly fine for me.

Regards,
Kamenee

On Tue, Jun 21, 2016 at 2:21 PM, Greg Clayton <gclayton at apple.com> wrote:

> We currently don't expose this information through the API, though we
> could. You could add a new method to SBValue:
>
> namespace lldb
> {
>   class SBValue
>   {
>     SBData GetDWARFLocation();
>   }
> };
>
> This could return the DWARF location as a SBData object. Then you could
> consume the data by parsing the DWARF DW_OP enumerations. Otherwise you can
> parse the textual output of the "image lookup -va 0x123" command:
>
> result = lldb.SBCommandReturnObject()
> ci = debugger.GetCommandInterpreter()
> ci.HandleCommand("image lookup -va %#x" % (frame.GetPC()), result, False)
>
> # Now all output from the above command is in "result"
> output = result.GetOutput()
>
> # Parse "output" for variable locations
>
>
>
>
> > On Jun 21, 2016, at 9:07 AM, Kamenee Arumugam <kamenee at seas.upenn.edu>
> wrote:
> >
> > Hi Greg,
> >
> > Thanks for your reply. I did try the method you mention above but
> variable.GetLocation() only provide me the memory address of the variable.
> What exactly I am looking for was  the register offset that stores variable
> i here. Example, I am looking for method able to output the one highlighted
> in yellow:
> >
> > Variable: id = {0x000000a2}, name = "i", type= "int", location =
> DW_OP_fbreg(-564), decl = ivm_demo.c:6
> >
> >
> > Basically, I am working on  a binary instrumentation research tool, that
> will inject code to check changes on selected variable. Therefore, using
> register offset, I am able to inject check for instruction using this
> register with this offset.
> > Please let me know if you have any better method to grab register offset
> for particular variable.
> >
> > Thanks,
> > Kamenee
> >
> > On Mon, Jun 20, 2016 at 7:15 PM, Greg Clayton <gclayton at apple.com>
> wrote:
> > The variables are available through the frame in your symbol context.
> You have a line of code commented out in your script:
> >
> >                     #variable = frame.GetVariables(target,True,True,True)
> >
> > Change it to:
> >
> > get_arguments = True # Get argument variables
> > get_locals = True # Get local variables
> > get_statics = True # Get globals and static variables
> > get_in_scope_only = True # only get variables that are in scope
> > use_dynamic = lldb.eDynamicDontRunTarget # Get dynamic types for
> variables
> > variables = frame.GetVariables (get_arguments, get_locals, get_statics,
> get_in_scope_only, use_dynamic)
> > print variables
> >
> > This output will look different from the output in "image lookup
> --address 0x... --verbose" because we have an actual frame here so we can
> dump the variable value itself because we have a stack frame that allows us
> to have variable values. If you want the location of the variable you can
> also print that in a for loop using "variables" from above:
> >
> > for variable in variables:
> >     print str(variable)
> >     print "Location = %s" % (variable.GetLocation())
> >
> >
> > Each "variable" object is a lldb.SBValue type. There are many API calls
> on these that you can call manually depending on what you want. Let me know
> if you have any questions.
> >
> > Greg Clayton
> >
> >
> >
> >
> > > On Jun 17, 2016, at 11:34 AM, Kamenee Arumugam via lldb-dev <
> lldb-dev at lists.llvm.org> wrote:
> > >
> > > Hi,
> > >
> > > I am trying program using Lldb Python API to get an output exactly
> same when I run this command "image lookup --address 0x0000000405a6
> --verbose". But when I print return value of
> GetSymbolContext(lldb.eSymbolContextEverything), it doesnt contain the
> decoding of local variables which the above commands can print out local
> variables.
> > >
> > > I have attached a simple script.py that I have developed. It is not
> possible to print out local variables using the APIs or I am missing
> something out?
> > >
> > > I am looking forward to hear from you soon.
> > >
> > > Thanks,
> > > kmn
> > > <script.txt>_______________________________________________
> > > lldb-dev mailing list
> > > lldb-dev at lists.llvm.org
> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> >
> >
>
>
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