static 在C的用法理解_ebx 存储 static-优快云博客

本文链接：https://blog.youkuaiyun.com/zhangmiaoping23/article/details/3423567

本文通过一个具体的C++示例，详细解析了静态变量的概念及其在函数中的行为特点，并通过汇编代码进一步说明静态变量的存储机制。

static variable in a function

1.Allocated once at a fixed address,that is , the object is created in a special static data area rather than on the stack each time a function is called.This is the concept of static storage.

#include <iostream>
using namespace std;

int test(int a)
{
static int i=3;//第一次调用函数时,初始化.第二次调用函数时,此句不执行

i++;
return i;
}
int main()
{
cout<<test(3)<<endl;
cout<<test(3)<<endl;
}

输出结果:4 5

--- F:/1/file1.cpp  ------------------------------------------------------------------------------------------------------
1:    #include <iostream>
2:    using namespace std;
3:
4:    int test(int a)
5:    {
00401030   push        ebp
00401031   mov         ebp,esp
00401033   sub         esp,40h
00401036   push        ebx
00401037   push        esi
00401038   push        edi
00401039   lea         edi,[ebp-40h]
0040103C   mov         ecx,10h
00401041   mov         eax,0CCCCCCCCh
00401046   rep stos    dword ptr [edi]
6:        static int i=3;//注意这句没相应的汇编,变量存在静态存储区 
7:
8:        i++;
00401048   mov         eax,[___xt_z+110h (00434dc0)]
//内存跟踪   00434DC0  03 00 00 00 
0040104D   add         eax,1
00401050   mov         [___xt_z+110h (00434dc0)],eax
9:        return i;
00401055   mov         eax,[___xt_z+110h (00434dc0)]
10:   }
0040105A   pop         edi
0040105B   pop         esi
0040105C   pop         ebx
0040105D   mov         esp,ebp
0040105F   pop         ebp
00401060   ret
--- F:/1/file1.cpp  ------------------------------------------------------------------------------------------------------
11:   int main()
12:   {
00401070   push        ebp
00401071   mov         ebp,esp
00401073   sub         esp,40h
00401076   push        ebx
00401077   push        esi
00401078   push        edi
00401079   lea         edi,[ebp-40h]
0040107C   mov         ecx,10h
00401081   mov         eax,0CCCCCCCCh
00401086   rep stos    dword ptr [edi]
13:       test(3);
00401088   push        3
0040108A   call        @ILT+0(test) (00401005)
0040108F   add         esp,4   //由push   3这条指令引起,堆栈平衡 
14:       test(3);
00401092   push        3
00401094   call        @ILT+0(test) (00401005)
00401099   add         esp,4
15:   }
0040109C   pop         edi
0040109D   pop         esi
0040109E   pop         ebx
0040109F   add         esp,40h
004010A2   cmp         ebp,esp//?这两句的作用是? 
004010A4   call        __chkesp (00408190)//? 
004010A9   mov         esp,ebp
004010AB   pop         ebp
004010AC   ret

2.File static

Local to a particular translation unit (and local to a class scope in C++,as you will see later),Here ,static controls the visibility of a name.So the name can not be seen outside the translation unit or class.This also describes the concept of linkage,which determines what names the linker will see.

这个我无法从汇编中看出区别.希望高手赐教.

网上找到的call _chkesp(******)的资料

调试版才会有，检查栈是否被破坏了.这样就能及时在你出错的地方停下了告诉你.发行版自动消除这些代码(调试产生的).有时候也可以手工加入这些调试检查代码，用于检查并确定错误所在位置。

关闭/GZ开关,可以去掉