内存地址上的监视点 [英] Watch points on memory address

问题描述

随着从gdb到lldb的新变化，我找不到一种在某些内存地址上设置监视点的方法.

With the new change from gdb to lldb , I can't find a way how to set watch points on some memory addresses .

在gdb中，我使用了

watch -location *0x123456

在lldb中做同样的事情

Doing the same in lldb

w s e *0x123456

不是为我工作. 那我可以用什么来在lldb中运行相同的命令?

Isn't working for me . So what can I use to run the same command in lldb ?

推荐答案

在lldb中设置监视点时，请省略取消引用运算符" *，只需传递地址即可:

Omit the "dereferencing operator" * when setting the watch point in lldb, just pass the address:

watchpoint set expression -- 0x123456
# short form:
w s e -- 0x123456

在存储位置0x123456上设置观察点. (可选)您可以设置要使用--size观看的字节数.简短示例:

sets a watchpoint at the memory location 0x123456. Optionally you can set the number of bytes to watch with --size. Example in short form:

w s e -s 2 -- 0x123456

您还可以在变量上设置观察点:

You can also set a watchpoint on a variable:

watchpoint set variable <variable>
# short form:
w s v <variable>

示例:在第二行中设置了以下代码和断点:

Example: With the following code and a breakpoint set at the second line:

int x = 2;
x = 5;

我是在Xcode调试器控制台中完成的:

I did this in the Xcode debugger console:

(lldb) p &x
(int *) $0 = 0xbfffcbd8
(lldb) w s e -- 0xbfffcbd8
Watchpoint created: Watchpoint 1: addr = 0xbfffcbd8 size = 4 state = enabled type = w
    new value: 2
(lldb) n

Watchpoint 1 hit:
old value: 2
new value: 5
(lldb)

更简单地说，我可以通过以下方式设置观察点

More simply, I could have set the watchpoint with

(lldb) w s v x
Watchpoint created: Watchpoint 1: addr = 0x7fff5fbff7dc size = 4 state = enabled type = w
    declare @ '/Users/martin/Documents/tmpprojects/watcher/watcher/main.c:16'
    watchpoint spec = 'x'

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