# Copyright 2017 the V8 project authors. All rights reserved. # Use of this source code is governed by a BSD-style license that can be # found in the LICENSE file. # Load this file by adding this to your ~/.lldbinit: # command script import <this_dir>/lldb_commands.py # for py2/py3 compatibility from __future__ import print_function import lldb import re ##################### # Helper functions. # ##################### def current_thread(debugger): return debugger.GetSelectedTarget().GetProcess().GetSelectedThread() def current_frame(debugger): return current_thread(debugger).GetSelectedFrame() def no_arg_cmd(debugger, cmd): evaluate_result = current_frame(debugger).EvaluateExpression(cmd) # When a void function is called the return value type is 0x1001 which # is specified in http://tiny.cc/bigskz. This does not indicate # an error so we check for that value below. kNoResult = 0x1001 error = evaluate_result.GetError() if error.fail and error.value != kNoResult: print("Failed to evaluate command {} :".format(cmd)) print(error.description) else: print("") def ptr_arg_cmd(debugger, name, param, cmd): if not param: print("'{}' requires an argument".format(name)) return param = '(void*)({})'.format(param) no_arg_cmd(debugger, cmd.format(param)) ##################### # lldb commands. # ##################### def job(debugger, param, *args): """Print a v8 heap object""" ptr_arg_cmd(debugger, 'job', param, "_v8_internal_Print_Object({})") def jlh(debugger, param, *args): """Print v8::Local handle value""" ptr_arg_cmd(debugger, 'jlh', param, "_v8_internal_Print_Object(*(v8::internal::Object**)({}.val_))") def jco(debugger, param, *args): """Print the code object at the given pc (default: current pc)""" if not param: param = str(current_frame(debugger).FindRegister("pc").value) ptr_arg_cmd(debugger, 'jco', param, "_v8_internal_Print_Code({})") def jtt(debugger, param, *args): """Print the transition tree of a v8 Map""" ptr_arg_cmd(debugger, 'jtt', param, "_v8_internal_Print_TransitionTree({})") def jst(debugger, *args): """Print the current JavaScript stack trace""" no_arg_cmd(debugger, "_v8_internal_Print_StackTrace()") def jss(debugger, *args): """Skip the jitted stack on x64 to where we entered JS last""" frame = current_frame(debugger) js_entry_sp = frame.EvaluateExpression( "v8::internal::Isolate::Current()->thread_local_top()->js_entry_sp_;") \ .GetValue() sizeof_void = frame.EvaluateExpression("sizeof(void*)").GetValue() rbp = frame.FindRegister("rbp") rsp = frame.FindRegister("rsp") pc = frame.FindRegister("pc") rbp = js_entry_sp rsp = js_entry_sp + 2 *sizeof_void pc.value = js_entry_sp + sizeof_void def bta(debugger, *args): """Print stack trace with assertion scopes""" func_name_re = re.compile("([^(<]+)(?:\(.+\))?") assert_re = re.compile( "^v8::internal::Per\w+AssertType::(\w+)_ASSERT, (false|true)>") thread = current_thread(debugger) for frame in thread: functionSignature = frame.GetDisplayFunctionName() if functionSignature is None: continue functionName = func_name_re.match(functionSignature) line = frame.GetLineEntry().GetLine() sourceFile = frame.GetLineEntry().GetFileSpec().GetFilename() if line: sourceFile = sourceFile + ":" + str(line) if sourceFile is None: sourceFile = "" print("[%-2s] %-60s %-40s" % (frame.GetFrameID(), functionName.group(1), sourceFile)) match = assert_re.match(str(functionSignature)) if match: if match.group(3) == "false": prefix = "Disallow" color = "\033[91m" else: prefix = "Allow" color = "\033[92m" print("%s -> %s %s (%s)\033[0m" % ( color, prefix, match.group(2), match.group(1))) def __lldb_init_module(debugger, dict): debugger.HandleCommand('settings set target.x86-disassembly-flavor intel') for cmd in ('job', 'jlh', 'jco', 'jld', 'jtt', 'jst', 'jss', 'bta'): debugger.HandleCommand( 'command script add -f lldb_commands.{} {}'.format(cmd, cmd))