Why GDB "bounces" when debugging using c source codes

Question

I am debugging the android kernel of goldfish (version 3.4) with kernel sources.

Now I found that gdb sometimes skips between lines, for example, consider the source code c as follows:

char *XXX;
int a;
...

if (...)
{

}

When I have reached the sentence if, enter nand return to the part int a. Why is this?

If I run this command again, it will go into brackets in if.

If possible, I want to avoid this part, and directly type if (of course, if the condition matches)

Answer 1

When I reach the if clause, I type n and it will return to the int part. Why is this?

, ( ) , "" ( ( ) , ).

gcc-4.8 , -Og. , . .