Source code for angr.analyses.class_identifier

from ..sim_type import SimCppClass, SimTypeCppFunction
from ..analyses import AnalysesHub
from . import Analysis, CFGFast, VtableFinder


class ClassIdentifier(Analysis):
    """
    This is a class identifier for non stripped or partially stripped binaries, it identifies classes based on the
    demangled function names, and also assigns functions to their respective classes based on their names. It also uses
    the results from the VtableFinder analysis to assign the corresponding vtable to the classes.

     self.classes contains a mapping between class names and SimCppClass objects

     e.g. A::tool() and A::qux() belong to the class A
    """

    def __init__(self):
        if "CFGFast" not in self.project.kb.cfgs:
            self.project.analyses[CFGFast].prep()(cross_references=True)
        self.classes = {}
        vtable_analysis = self.project.analyses[VtableFinder].prep()()
        self.vtables_list = vtable_analysis.vtables_list
        self._analyze()

    def _analyze(self):
        # Assigning function to classes
        for func in self.project.kb.functions.values():
            if func.is_plt:
                continue
            col_ind = func.demangled_name.rfind("::")
            class_name = func.demangled_name[:col_ind]
            if class_name.startswith("non-virtual thunk for "):
                class_name = class_name[len("non-virtual thunk for ") :]
            if col_ind != -1:
                if class_name not in self.classes:
                    ctor = False
                    if func.demangled_name.find("{ctor}"):
                        ctor = True
                    function_members = {func.addr: SimTypeCppFunction([], None, label=func.demangled_name, ctor=ctor)}
                    new_class = SimCppClass(name=class_name, function_members=function_members)
                    self.classes[class_name] = new_class

                else:
                    ctor = False
                    if func.demangled_name.find("{ctor}"):
                        ctor = True
                    cur_class = self.classes[class_name]
                    cur_class.function_members[func.addr] = SimTypeCppFunction(
                        [], None, label=func.demangled_name, ctor=ctor
                    )

        # Assigning a vtable to a class
        for vtable in self.vtables_list:
            for ref in self.project.kb.xrefs.xrefs_by_dst[vtable.vaddr]:
                vtable_calling_func = self.project.kb.functions.floor_func(ref.ins_addr)
                tmp_col_ind = vtable_calling_func.demangled_name.rfind("::")
                possible_constructor_class_name = vtable_calling_func.demangled_name[:tmp_col_ind]
                if "ctor" in vtable_calling_func.demangled_name and possible_constructor_class_name in self.classes:
                    self.classes[possible_constructor_class_name].vtable_ptrs.append(vtable.vaddr)


AnalysesHub.register_default("ClassIdentifier", ClassIdentifier)