Undocumented dependency on Cs object in python API about capstone HOT 4 CLOSED

On Mon, Dec 23, 2013 at 4:49 AM, felixwilhelm [email protected]:

Hi,

the python API fails silently when the Cs object goes out of scope. I am
not sure about the best way to fix this. The del method of Cs calls
cs_close which makes a big chunk of the API unusable.
Adding a reference to Cs in each object is an easy fix, but adds an
(inacceptable) overhead to each instruction object. A better way might be
some kind of internal reference counting to ensure that cs_close is only
called when all instruction are out of scope as well.

Example code:

import capstone

def test_disasm():
md = capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_32)
# jmp esp
instr = md.disasm("\xff\xe4",0x10,1)[0]
print instr.reg_name(instr.operands[0].value.reg) # "esp"
return instr

instr2 = test_disasm()
print instr2.reg_name(instr2.operands[0].value.reg) # "None"

If this is the desired behavior, it should be documented more clearly.

This is not a designed behavior. We will work on this, and get back to you
soon.

Thanks.

from capstone.

On Mon, Dec 23, 2013 at 10:20 AM, Nguyen Anh Quynh [email protected] wrote:

On Mon, Dec 23, 2013 at 4:49 AM, felixwilhelm [email protected]:

Hi,

the python API fails silently when the Cs object goes out of scope. I am
not sure about the best way to fix this. The del method of Cs calls
cs_close which makes a big chunk of the API unusable.
Adding a reference to Cs in each object is an easy fix, but adds an
(inacceptable) overhead to each instruction object.

Btw, why adding reference to Cs adds "inacceptable overhead" to CsInsn?

Thanks.

from capstone.

On Mon, Dec 23, 2013 at 11:18 AM, Nguyen Anh Quynh [email protected] wrote:

On Mon, Dec 23, 2013 at 10:20 AM, Nguyen Anh Quynh [email protected]:

On Mon, Dec 23, 2013 at 4:49 AM, felixwilhelm [email protected]:

Hi,

the python API fails silently when the Cs object goes out of scope. I am
not sure about the best way to fix this. The del method of Cs calls
cs_close which makes a big chunk of the API unusable.
Adding a reference to Cs in each object is an easy fix, but adds an
(inacceptable) overhead to each instruction object.

Btw, why adding reference to Cs adds "inacceptable overhead" to CsInsn?

Felix, i just commited a fix for this issue to "next" branch. could you
confirm it works for you?

thanks.

from capstone.

Thanks for the quick fix :). Works like a charm.

from capstone.