Question

我在长期计划中有一个全局功能：

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

我希望在我点击test()之后每行都在call test()方法中断，而不是立即返回结果。谁知道怎么做？

------------------------------------以下答案--------- ---------------------------

@Jason Molenda的回答是正确答案，请使用expr -i0 -- test()代替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)

现在它突破了test()，但引发了错误！如何避免错误？

Answer 1

lldb中的expression命令（call是expression的别名）需要十几个选项，其中一个是lldb是否应该在执行表达式时在断点处停止，--ignore-breakpoints false或-i false或-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)

有一些想法投入到默认行为（是否在断点处停止），这似乎是大多数人所期望的行为。

正如我所说，call命令只是expression的别名。如果要更改其行为，可以使用自己的别名覆盖别名。例如command alias call expr -i false --会做到这一点。您可以将其放在~/.lldbinit文件中，然后设置即可。

Answer 2

这不是开玩笑吗？只需检查标准断点即可：

(gdb) b test
Breakpoint 2 at 0x400671: file t.c, line 6.
(gdb) call test()

Breakpoint 2, test () at t.c:6
6       printf("a\n");

gdb / lldb调用一个函数并中断它

2 个答案: