Merge pull request #3 from quarkslab/fix_weak_ref

Fix circular references and some typos

binexport/__init__.py

@@ -2,5 +2,5 @@
 from .function import FunctionBinExport
 from .basic_block import BasicBlockBinExport
 from .instruction import InstructionBinExport
-from.operand import OperandBinExport
+from .operand import OperandBinExport
 from .expression import ExpressionBinExport

binexport/basic_block.py

@@ -14,7 +14,7 @@ class BasicBlockBinExport(OrderedDict):
     methods to access instructions.
     """
 
-    def __init__(self, program: "ProgramBinExport", function: "FunctionBinExport", pb_bb: "BinExport2.BasicBlock"):
+    def __init__(self, program: weakref.ref["ProgramBinExport"], function: weakref.ref["FunctionBinExport"], pb_bb: "BinExport2.BasicBlock"):
         """
         :param program: Weak reference to the program
         :param function: Weak reference to the function
@@ -29,16 +29,15 @@ def __init__(self, program: "ProgramBinExport", function: "FunctionBinExport", p
         self.bytes = b""  #: bytes of the basic block
 
         # Ranges are in fact the true basic blocks but BinExport
-        # don't have the same basic block semantic and merge multiple basic blocks into one.
+        # doesn't have the same basic block semantic and merge multiple basic blocks into one.
         # For example: BB_1 -- unconditional_jmp --> BB_2
-        # might be merged into a single basic block so lose the edge
+        # might be merged into a single basic block so the edge gets lost.
         for rng in pb_bb.instruction_index:
             for idx in instruction_index_range(rng):
                 pb_inst = self.program.proto.instruction[idx]
                 inst_addr = get_instruction_address(self.program.proto, idx)
 
                 # The first instruction determines the basic block address
-                # Save the first instruction to guess the instruction set
                 if self.addr is None:
                     self.addr = inst_addr
 

binexport/expression.py

@@ -67,18 +67,14 @@ def __init__(self,
         self.is_addr: bool = False  #: whether the value is referring to an address
         self.is_data: bool = False  #: whether the value is a reference to data
 
+        # Expression object in the protobuf structure
+        self.pb_expr = program.proto.expression[self._idx]
+
         self._parse_protobuf(program, function, instruction)
 
     def __hash__(self) -> int:
         return hash(self._idx)
 
-    @property
-    def pb_expr(self) -> BinExport2.Expression:
-        """
-        Returns the operand object in the protobuf structure
-        """
-        return self.program.proto.expression[self._idx]
-
     @property
     def type(self) -> ExpressionType:
         """
@@ -112,46 +108,45 @@ def _parse_protobuf(self,
         """
         Low-level expression parser. It populates self._type and self._value
         """
-        pb_expr = program.proto.expression[self._idx]
-        if pb_expr.type == BinExport2.Expression.SYMBOL:
-            self._value = pb_expr.symbol
+        if self.pb_expr.type == BinExport2.Expression.SYMBOL:
+            self._value = self.pb_expr.symbol
 
-            if pb_expr.symbol in program.fun_names:  # It is a function name
+            if self.pb_expr.symbol in program.fun_names:  # It is a function name
                 self._type = ExpressionType.FUNC_NAME
             else:  # It is a local symbol (ex: var_, arg_)
                 self._type = ExpressionType.VAR_NAME
 
-        elif pb_expr.type == BinExport2.Expression.IMMEDIATE_INT:
+        elif self.pb_expr.type == BinExport2.Expression.IMMEDIATE_INT:
             self._type = ExpressionType.IMMEDIATE_INT
-            self._value = to_signed(pb_expr.immediate, program.mask)
+            self._value = to_signed(self.pb_expr.immediate, program.mask)
 
-            if pb_expr.immediate in instruction.data_refs:  # Data
+            if self.pb_expr.immediate in instruction.data_refs:  # Data
                 self.is_addr = True
                 self.is_data = True
             elif (
-                pb_expr.immediate in program or pb_expr.immediate in function
+                self.pb_expr.immediate in program or self.pb_expr.immediate in function
             ):  # Address
                 self.is_addr = True
 
-        elif pb_expr.type == BinExport2.Expression.IMMEDIATE_FLOAT:
+        elif self.pb_expr.type == BinExport2.Expression.IMMEDIATE_FLOAT:
             self._type = ExpressionType.IMMEDIATE_FLOAT
-            self._value = pb_expr.immediate  # Cast it to float
+            self._value = self.pb_expr.immediate  # Cast it to float
 
-        elif pb_expr.type == BinExport2.Expression.OPERATOR:
+        elif self.pb_expr.type == BinExport2.Expression.OPERATOR:
             self._type = ExpressionType.SYMBOL
-            self._value = pb_expr.symbol
+            self._value = self.pb_expr.symbol
 
-        elif pb_expr.type == BinExport2.Expression.REGISTER:
+        elif self.pb_expr.type == BinExport2.Expression.REGISTER:
             self._type = ExpressionType.REGISTER
-            self._value = pb_expr.symbol
+            self._value = self.pb_expr.symbol
 
-        elif pb_expr.type == BinExport2.Expression.SIZE_PREFIX:
+        elif self.pb_expr.type == BinExport2.Expression.SIZE_PREFIX:
             self._type = ExpressionType.SIZE
-            self._value = self.__sz_lookup[pb_expr.symbol]
+            self._value = self.__sz_lookup[self.pb_expr.symbol]
 
-        elif pb_expr.type == BinExport2.Expression.DEREFERENCE:
+        elif self.pb_expr.type == BinExport2.Expression.DEREFERENCE:
             self._type = ExpressionType.SYMBOL
-            self._value = pb_expr.symbol
+            self._value = self.pb_expr.symbol
 
         else:
-            logging.error(f"Malformed protobuf message. Invalid expression type {pb_expr.type}")
+            logging.error(f"Malformed protobuf message. Invalid expression type {self.pb_expr.type}")

binexport/instruction.py

@@ -1,4 +1,5 @@
 import weakref
+from functools import cached_property
 
 from binexport.operand import OperandBinExport
 from binexport.types import Addr
@@ -10,7 +11,7 @@ class InstructionBinExport:
     Instruction class. It represents an instruction with its operands.
     """
 
-    def __init__(self, program: "ProgramBinExport", function: "FunctionBinExport", addr: Addr, i_idx: int):
+    def __init__(self, program: weakref.ref["ProgramBinExport"], function: weakref.ref["FunctionBinExport"], addr: Addr, i_idx: int):
         """
         :param program: Weak reference to the program
         :param function: Weak reference to the function
@@ -54,10 +55,11 @@ def mnemonic(self) -> str:
         """
         return self.program.proto.mnemonic[self.pb_instr.mnemonic_index].name
 
-    @property
+    @cached_property
     def operands(self) -> List[OperandBinExport]:
         """
         Returns a list of the operands instanciated dynamically on-demand.
+        The list is cached by default, to erase the cache delete the attribute.
         """
         return [
             OperandBinExport(self._program, self._function, weakref.ref(self), op_idx)

binexport/operand.py

@@ -111,6 +111,7 @@ def expressions(self) -> List[ExpressionBinExport]:
         """
         Iterates over all the operand expression in a pre-order manner
         (binary operator first).
+        The list is cached by default, to erase the cache delete the attribute
         """
 
         expr_dict = {}  # {expression protobuf idx : ExpressionBinExport}