terrynini/IDAmetrics

IDA plugin for software complexity metrics assessment

IDAMetrics-static.py

This repo forked from https://github.com/mxmssh/IDAmetrics, go to check the original README for more information.

What I did is porting IDAMetrics_static.py from IDA 5.5.0 (32 bit) to IDA 7.5.200519 (32 bit).

Bug fix

GetInstructionType function was erroneous, inaccuracy and hard to extend to x86_64.

The erroneous result of GetInstructionType

The implementation of GetInstructionType function was based on string matching which is erroneous and inaccuracy, e.g. the leave instruction would be counted as ASSIGNMENT_INSTRUCTION just because the startswith("lea") of leave is apparently True:

for assign_instr_mnem in assign_instructions_general:
        if instr_mnem.startswith(assign_instr_mnem):
            return inType.ASSIGNMENT_INSTRUCTION

The root cause of inaccuracy of GetInstructionType

Also, because the string matching need someone manually build a list. There may be omissions from the list. For example, setnz should be included in assign_instructions_general.

assign_instructions_general = [
    "mov", "cmov", "xchg", "bswap", "xadd", "ad", "sub", "sbb", "imul", "mul",
    "idiv", "div", "inc", "dec", "neg", "da", "aa", "and", "or", "xor", "not",
    "sar", "shr", "sal", "shl", "shrd", "shld", "ror", "rol", "rcr", "rcl",
    "lod", "sto", "lea"
]

How to fix

This kind of information should has been gained by IDA during the analyzing. Using APIs in module ida_idp should solve some problems.