前言
日常的Xcode开发中，我们时常用【All Exceptions Breakpoint】来定位一些异常情况的断点
但该功能同时也会在@try@catch或者在使用诸如CoreData或Accessibility之类的异常大量框架时，很难追踪到您实际遇到的异常
解决方法
建立脚本
- 采用以下脚本生成ignore_specified_objc_exceptions.py文件
import lldb
import re
import shlex
# This script allows Xcode to selectively ignore Obj-C exceptions
# based on any selector on the NSException instance
def getRegister(target):
if target.triple.startswith('x86_64'):
return "rdi"
elif target.triple.startswith('i386'):
return "eax"
elif target.triple.startswith('arm64'):
return "x0"
else:
return "r0"
def callMethodOnException(frame, register, method):
return frame.EvaluateExpression("(NSString *)[(NSException *)${0} {1}]".format(register, method)).GetObjectDescription()
def filterException(debugger, user_input, result, unused):
target = debugger.GetSelectedTarget()
frame = target.GetProcess().GetSelectedThread().GetFrameAtIndex(0)
if frame.symbol.name != 'objc_exception_throw':
# We can't handle anything except objc_exception_throw
return None
filters = shlex.split(user_input)
register = getRegister(target)
for filter in filters:
method, regexp_str = filter.split(":", 1)
value = callMethodOnException(frame, register, method)
if value is None:
output = "Unable to grab exception from register {0} with method {1}; skipping...".format(register, method)
result.PutCString(output)
result.flush()
continue
regexp = re.compile(regexp_str)
if regexp.match(value):
output = "Skipping exception because exception's {0} ({1}) matches {2}".format(method, value, regexp_str)
result.PutCString(output)
result.flush()
# If we tell the debugger to continue before this script finishes,
# Xcode gets into a weird state where it won't refuse to quit LLDB,
# so we set async so the script terminates and hands control back to Xcode
debugger.SetAsync(True)
debugger.HandleCommand("continue")
return None
return None
def __lldb_init_module(debugger, unused):
debugger.HandleCommand('command script add --function ignore_specified_objc_exceptions.filterException ignore_specified_objc_exceptions')
- 将此脚本放在某处（例如~/Library/lldb/ignore_specified_objc_exceptions.py）
- 在~/.lldbinit中添加以下内容：
command script import ~/Library/lldb/ignore_specified_objc_exceptions.py
~/Library/lldb/ignore_specified_objc_exceptions.py如果您将其保存在其他位置，请替换为正确的路径。
使用方法
- All Exceptions Breakpoint选择Objective-C
- Debugger Command中添加以下语句：
ignore_specified_objc_exceptions className:DTRpcException name: NSAccessibilityException
这样就忽略类名为DTRpcException或者name为NSAccessibilityException的异常
快捷部署方法
一键部署脚本：
mkdir -p ~/Library/lldb
curl -L https://gist.github.com/chendo/6759305/raw/ignore_specified_objc_exceptions.py > ~/Library/lldb/ignore_specified_objc_exceptions.py
echo "command script import ~/Library/lldb/ignore_specified_objc_exceptions.py" >> ~/.lldbinit
参考：这里
