def run()

in commands/FBDebugCommands.py [0:0]

• 31 lines of code
• 14 McCabe index (conditional complexity)

    def run(self, arguments, options):
        # This command is like `expression --synthetic-type false`,
        # except only showing nested heap references.
        var = self.context.frame.var(arguments[0])
        if not var or not var.IsValid():
            self.result.SetError('No variable named "{}"'.format(arguments[0]))
            return

        # Use the actual underlying structure of the variable,
        # not the human friendly (synthetic) one.
        root = var.GetNonSyntheticValue()

        # Traversal of SBValue tree to get leaf nodes, which is where heap
        # pointers will be.
        leafs = []
        queue = [root]
        while queue:
            node = queue.pop(0)
            if node.num_children == 0:
                leafs.append(node)
            else:
                queue += [node.GetChildAtIndex(i) for i in range(node.num_children)]

        pointers = {}
        for node in leafs:
            # Assumption: an addr that has no value means a pointer.
            if node.addr and not node.value:
                pointers[node.load_addr] = node.path

        options = lldb.SBExpressionOptions()
        options.SetLanguage(lldb.eLanguageTypeC)

        def isHeap(addr):
            lookup = "(int)malloc_size({})".format(addr)
            return self.context.frame.EvaluateExpression(lookup, options).unsigned != 0

        allocations = (addr for addr in pointers if isHeap(addr))
        for addr in allocations:
            print(
                "0x{addr:x} {path}".format(addr=addr, path=pointers[addr]),
                file=self.result,
            )
        if not allocations:
            print("No heap addresses found", file=self.result)