Objective - C 内存管理（三）内存布局

(一)iOS程序的内存布局

下面如何验证：

//我们在main函数中，直接添加下面的变量 并将其地址输出
int a = 10;
int b;

int main(int argc, char * argv[]) {
    NSString * appDelegateClassName;
    @autoreleasepool {
        static int c = 20;
        static int d;
        int e;
        int f = 20;
        
        NSString *str = @"123";
        NSObject *obj = [[NSObject alloc]init];
        NSObject *obj2 = [[NSObject alloc]init];
        
        NSLog(@"\n全局已初始化\t\ta = %p\n全局未初始化\t\tb = %p\n静态已初始化变量\tc = %p\n静态未初始化变量\td = %p\n变量未初始化\t\te = %p\n变量已初始化\t\tf = %p\n字符串常量\t  str = %p\n类对象\t\t  obj = %p\n类对象2\t\t  obj = %p\n",&a,&b,&c,&d,&e,&f,str,obj,obj2);//str与obj存放的就是实际地址的指向  自身还是在栈区
        
        
        // Setup code that might create autoreleased objects goes here.
        appDelegateClassName = NSStringFromClass([AppDelegate class]);
    }
    return UIApplicationMain(argc, argv, nil, appDelegateClassName);
}

输出结果，进行比对：

 
 //数据段
 
 //字符串常量区
 str  = 0x108eca198
 
 //已初始化数据区
 &a   = 0x108ecc838
 &c   = 0x108ecc83c
 
 //未初始化数据区
 &d   = 0x108ecc918
 &b   = 0x108ecc91c
 
 //堆 从小到大
 obj  = 0x600000d68040
 obj2 = 0x600000d680a0
 
 //栈 从大到小
 &e   = 0x7ffee6d37d04
 &f   = 0x7ffee6d37d00

即可证明。之后我们通过逆向也可证明，暂不讲述。