simple example of BN functionrecognizer

function_reg_test.py

from binaryninja.functionrecognizer import FunctionRecognizer
from binaryninja.enums import MediumLevelILOperation, BranchType
from binaryninja.log import log

class CheckArgRec(FunctionRecognizer):
    def recognize_medium_level_il(self, data, func, il):
        for edge in il.basic_blocks[0].outgoing_edges:
            if edge.type == BranchType.FalseBranch:
                for i in edge.target:
                    if i.operation == MediumLevelILOperation.MLIL_CALL:
                        if len(i.operands) == 3 and len(i.operands[2]) == 2 and i.operands[2][1].value == 0x2f:
                            il.source_function.name = 'validate_args'
                            return True
        return False

CheckArgRec().register_global()