gdb / lldb调用一个函数并打断它 [英] gdb/lldb call a function and break in it

问题描述

  int test（）
 {
 int a = 12; 
 int c = 10; 
 printf（a =％d，a）; 
 a + = c; 
 printf（a =％d，a）; 
返回a; 
} 
  

我调试程序并中断，然后发出以下命令：

 （lldb）call test（）
a = 12a = 22（int）$ 0 = 22 
（lldb）
  

我希望它在 test（）方法在每次按下 call test（）之后的每一行，而不仅仅是立即返回结果。任何人都知道如何做到这一点？

----------------------------------- - 下面的答案------------------------------------

@Jason Molenda的答案是正确的答案，使用 expr -i0 - test（）而不是 call test（）：

 （lldb）b测试
断点1：4个位置。 
（lldb）expr -i0  -  test（）
错误：执行中断，原因：断点1.1。 
该进程已经被中断，使用线程返回-x返回表达式评估之前的状态。 
（lldb）
  

现在在 test（），但会引发错误！如何避免错误？

解决方案

表达式 call 是表达式的别名）需要十几个选项，其中之一是lldb是否应该停止执行表达式时的断点， - ignore-breakpoints false 或 -i false 或 -i 0 。

 （lldb）br s -n printf 
断点2 ：where = libsystem_c.dylib`printf，address = 0x00007fff89ee7930 
（lldb）expr  - （void）printf（hi\\\
）
 hi 
（lldb）expr -i0  -  - （void）printf（hi\\\
）
错误：执行中断，原因：断点2.1。 
该进程已经被中断，使用线程返回-x返回表达式评估之前的状态。 
进程15259停止
 *线程＃1：tid = 0xf0daf，0x00007fff89ee7930 libsystem_c.dylib`printf，queue ='com.apple.main-thread'，stop reason = breakpoint 2.1 
＃0 ：0x00007fff89ee7930 libsystem_c.dylib`printf 
 libsystem_c.dylib`printf：
  - > 0x7fff89ee7930：pushq％rbp 
 0x7fff89ee7931：movq％rsp，％rbp 
 0x7fff89ee7934：pushq％r15 
 0x7fff89ee7936：pushq％r14 
（lldb）
  

对默认行为有一些想法（是否停止在断点上），这似乎是大多数人的行为期望。

正如我所说的，调用命令只是表达式的别名。如果你想改变它的行为，你可以用你自己的别名覆盖别名。例如命令别名调用expr -i false - 会执行该操作。你可以把它放在〜/ .lldbinit 文件中，你就可以设置。

I have a global function in a long run program :

int test()
{
    int a = 12;
    int c = 10;
    printf("a=%d",a);
    a += c ;
    printf("a=%d", a);
    return a;
}

I debug the program and break, then issue the following command:

(lldb) call test()
a=12a=22(int) $0 = 22
(lldb)

I want it to break in test() method every line after I hit call test(), not just return the result immediately. Anyone knows how to do it ?

------------------------------------ Answer Below ------------------------------------

@Jason Molenda 's answer is the right answer,use expr -i0 -- test() instead of call test():

(lldb) b test
Breakpoint 1: 4 locations.
(lldb) expr -i0 -- test()
error: Execution was interrupted, reason: breakpoint 1.1.
The process has been left at the point where it was interrupted, use "thread return -x" to return to the state before expression evaluation.
(lldb) 

Now it break in test(), but raise an error!!! How to avoid the error ?

解决方案

The expression command in lldb (call is an alias for expression) takes a dozen or so options, one of them being whether lldb should stop on a breakpoint while executing the expression, --ignore-breakpoints false, or -i false, or -i 0.

(lldb) br s -n printf
Breakpoint 2: where = libsystem_c.dylib`printf, address = 0x00007fff89ee7930
(lldb) expr -- (void)printf("hi\n")
hi
(lldb) expr -i0 -- (void)printf("hi\n")
error: Execution was interrupted, reason: breakpoint 2.1.
The process has been left at the point where it was interrupted, use "thread return -x" to return to the state before expression evaluation.
Process 15259 stopped
* thread #1: tid = 0xf0daf, 0x00007fff89ee7930 libsystem_c.dylib`printf, queue = 'com.apple.main-thread', stop reason = breakpoint 2.1
    #0: 0x00007fff89ee7930 libsystem_c.dylib`printf
libsystem_c.dylib`printf:
-> 0x7fff89ee7930:  pushq  %rbp
   0x7fff89ee7931:  movq   %rsp, %rbp
   0x7fff89ee7934:  pushq  %r15
   0x7fff89ee7936:  pushq  %r14
(lldb)  

There was some thought put in to the default behavior (whether to stop on a breakpoint or not), and this seemed the behavior most people would expect.

As I said, the call command is just an alias for expression. If you want to change the behavior of it, you can overwrite the alias with one of your own. e.g. command alias call expr -i false -- will do the trick. You can put this in your ~/.lldbinit file and you'll be set.

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