LLDB调试器

我们常用的p、po究竟是什么？

help

使用help命令查看LLDB的帮助文档，哪里不会查哪里

expression（简写e、expr）
首先我们来看看帮助文档怎么说（太长了，就不完全粘贴下来了）：

(lldb) help expression
     Evaluate an expression on the current thread.  Displays any returned value
     with LLDB's default formatting.  Expects 'raw' input (see 'help
     raw-input'.)

Syntax:

Command Options Usage:
......

Timeouts:
......

User defined variables:
......

Continuing evaluation after a breakpoint:
......

Examples:

    expr my_struct->a = my_array[3]
    expr -f bin -- (index * 8) + 5
    expr unsigned int $foo = 5
    expr char c[] = \"foo\"; c[0]
     
     Important Note: Because this command takes 'raw' input, if you use any
     command options you must use ' -- ' between the end of the command options
     and the beginning of the raw input.

归纳一下就是：

print（简写p）

简单来讲：'print' is an abbreviation for 'expression --'

验证一下：

(lldb) expression @"123"
(NSTaggedPointerString *) $0 = 0xa000000003332313 @"123"
(lldb) print @"123"
(NSTaggedPointerString *) $1 = 0xa000000003332313 @"123"

po

(lldb) help po
    Evaluate an expression on the current thread.  Displays any returned value
    with formatting controlled by the type's author. 
    'po' is an abbreviation for 'expression -O --'

经常打断点的你，如何更优雅的使用断点呢？

如何根据打印出来的堆栈信息，快速定位问题？