『iOS』各种不同情况下block相关的源码表现

这篇文章主要记录下，block在不同情况下的源码表现，目的在于加深自己对于block理解

相关命令

xcrun  -sdk  iphoneos  clang  -arch  arm64  -rewrite-objc  OC源文件  -o  输出的CPP文件
__weak无法生成源码的问题
clang -rewrite-objc -fobjc-arc -fobjc-runtime=macosx-10.14 main.m -o main1.cpp

1.

void (^block)(void);

void test()
{
    int age = 10;
    static int height = 10;
    
    block = ^{
        // age的值捕获进来（capture）
        NSLog(@"age is %d, height is %d", age, height);
    };
    
    age = 20;
    height = 20;
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        test();
        block();
    }
    return 0;
}

源码

void (*block)(void);


struct __test_block_impl_0 {
  struct __block_impl impl;
  struct __test_block_desc_0* Desc;
  int age;
  int *height;
  __test_block_impl_0(void *fp, struct __test_block_desc_0 *desc, int _age, int *_height, int flags=0) : age(_age), height(_height) {
    impl.isa = &_NSConcreteStackBlock;
    impl.Flags = flags;
    impl.FuncPtr = fp;
    Desc = desc;
  }
};
static void __test_block_func_0(struct __test_block_impl_0 *__cself) {
  int age = __cself->age; // bound by copy
  int *height = __cself->height; // bound by copy


        NSLog((NSString *)&__NSConstantStringImpl__var_folders_2r__m13fp2x2n9dvlr8d68yry500000gn_T_main_d2875b_mi_0, age, (*height));
    }

static struct __test_block_desc_0 {
  size_t reserved;
  size_t Block_size;
} __test_block_desc_0_DATA = { 0, sizeof(struct __test_block_impl_0)};
void test()
{
    int age = 10;
    static int height = 10;

    block = ((void (*)())&__test_block_impl_0((void *)__test_block_func_0, &__test_block_desc_0_DATA, age, &height));

    age = 20;
    height = 20;
}

int main(int argc, const char * argv[]) {
    /* @autoreleasepool */ { __AtAutoreleasePool __autoreleasepool; 
        test();
        ((void (*)(__block_impl *))((__block_impl *)block)->FuncPtr)((__block_impl *)block);
    }
    return 0;
}

2.

void (^block)(void);

int main(int argc, const char * argv[]) {
    @autoreleasepool {

        void (^block)(void) = ^{
            NSLog(@"Hello, World!");
        };

        block();
    }
    return 0;
}

源码

struct __block_impl {
    void *isa;
    int Flags;
    int Reserved;
    void *FuncPtr;
};

struct __main_block_impl_0 {
  struct __block_impl impl;
  struct __main_block_desc_0* Desc;
  // 构造函数（类似于OC的init方法），返回结构体对象
  __main_block_impl_0(void *fp, struct __main_block_desc_0 *desc, int flags=0) {
    impl.isa = &_NSConcreteStackBlock;
    impl.Flags = flags;
    impl.FuncPtr = fp;
    Desc = desc;
  }
};

// 封装了block执行逻辑的函数
static void __main_block_func_0(struct __main_block_impl_0 *__cself) {

            NSLog((NSString *)&__NSConstantStringImpl__var_folders_2r__m13fp2x2n9dvlr8d68yry500000gn_T_main_c60393_mi_0);
        }

static struct __main_block_desc_0 {
  size_t reserved;
  size_t Block_size;
} __main_block_desc_0_DATA = { 0, sizeof(struct __main_block_impl_0)};
int main(int argc, const char * argv[]) {
    /* @autoreleasepool */ { __AtAutoreleasePool __autoreleasepool;
        // 定义block变量
        void (*block)(void) = &__main_block_impl_0(
                                                   __main_block_func_0,
                                                   &__main_block_desc_0_DATA
                                                   );

        // 执行block内部的代码
        block->FuncPtr(block);
    }
    return 0;
}

3.

@implementation Person

int age_ = 10;

- (void)test
{
    void (^block)(void) = ^{
        NSLog(@"-------%d", [self name]);
    };
    block();
}

- (instancetype)initWithName:(NSString *)name
{
    if (self = [super init]) {
        self.name = name;
    }
    return self;
}

@end

源码

struct __MJPerson__test_block_impl_0 {
  struct __block_impl impl;
  struct __MJPerson__test_block_desc_0* Desc;
  MJPerson *self;
  __MJPerson__test_block_impl_0(void *fp, struct __MJPerson__test_block_desc_0 *desc, MJPerson *_self, int flags=0) : self(_self) {
    impl.isa = &_NSConcreteStackBlock;
    impl.Flags = flags;
    impl.FuncPtr = fp;
    Desc = desc;
  }
};
static void __MJPerson__test_block_func_0(struct __MJPerson__test_block_impl_0 *__cself) {
  MJPerson *self = __cself->self; // bound by copy

        NSLog((NSString *)&__NSConstantStringImpl__var_folders_2r__m13fp2x2n9dvlr8d68yry500000gn_T_MJPerson_1027e6_mi_0, ((NSString *(*)(id, SEL))(void *)objc_msgSend)((id)self, sel_registerName("name")));
    }
static void __MJPerson__test_block_copy_0(struct __MJPerson__test_block_impl_0*dst, struct __MJPerson__test_block_impl_0*src) {_Block_object_assign((void*)&dst->self, (void*)src->self, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static void __MJPerson__test_block_dispose_0(struct __MJPerson__test_block_impl_0*src) {_Block_object_dispose((void*)src->self, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static struct __MJPerson__test_block_desc_0 {
  size_t reserved;
  size_t Block_size;
  void (*copy)(struct __MJPerson__test_block_impl_0*, struct __MJPerson__test_block_impl_0*);
  void (*dispose)(struct __MJPerson__test_block_impl_0*);
} __MJPerson__test_block_desc_0_DATA = { 0, sizeof(struct __MJPerson__test_block_impl_0), __MJPerson__test_block_copy_0, __MJPerson__test_block_dispose_0};

static void _I_MJPerson_test(MJPerson * self, SEL _cmd) {
    void (*block)(void) = ((void (*)())&__MJPerson__test_block_impl_0((void *)__MJPerson__test_block_func_0, &__MJPerson__test_block_desc_0_DATA, self, 570425344));
    ((void (*)(__block_impl *))((__block_impl *)block)->FuncPtr)((__block_impl *)block);
}


static instancetype _I_MJPerson_initWithName_(MJPerson * self, SEL _cmd, NSString *name) {
    if (self = ((MJPerson *(*)(__rw_objc_super *, SEL))(void *)objc_msgSendSuper)((__rw_objc_super){(id)self, (id)class_getSuperclass(objc_getClass("MJPerson"))}, sel_registerName("init"))) {
        ((void (*)(id, SEL, NSString *))(void *)objc_msgSend)((id)self, sel_registerName("setName:"), (NSString *)name);
    }
    return self;
}

4.


typedef void (^MJBlock)(void);

int main(int argc, const char * argv[]) {
    @autoreleasepool {

        MJBlock block;

        {
            MJPerson *person = [[MJPerson alloc] init];
            person.age = 10;
            int age = 10;
            block = ^{
                NSLog(@"---------%d", person.age);
            };
        }

        NSLog(@"------");
    }
    return 0;
}

源码


typedef void (*MJBlock)(void);


struct __main_block_impl_0 {
  struct __block_impl impl;
  struct __main_block_desc_0* Desc;
  MJPerson *__strong person;
  __main_block_impl_0(void *fp, struct __main_block_desc_0 *desc, MJPerson *__strong _person, int flags=0) : person(_person) {
    impl.isa = &_NSConcreteStackBlock;
    impl.Flags = flags;
    impl.FuncPtr = fp;
    Desc = desc;
  }
};
static void __main_block_func_0(struct __main_block_impl_0 *__cself) {
  MJPerson *__strong person = __cself->person; // bound by copy

                NSLog((NSString *)&__NSConstantStringImpl__var_folders_mm_hfgvs481081__0wdsw776zfh0000gn_T_main_13ee9c_mi_0, ((int (*)(id, SEL))(void *)objc_msgSend)((id)person, sel_registerName("age")));
            }
static void __main_block_copy_0(struct __main_block_impl_0*dst, struct __main_block_impl_0*src) {_Block_object_assign((void*)&dst->person, (void*)src->person, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static void __main_block_dispose_0(struct __main_block_impl_0*src) {_Block_object_dispose((void*)src->person, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static struct __main_block_desc_0 {
  size_t reserved;
  size_t Block_size;
  void (*copy)(struct __main_block_impl_0*, struct __main_block_impl_0*);
  void (*dispose)(struct __main_block_impl_0*);
} __main_block_desc_0_DATA = { 0, sizeof(struct __main_block_impl_0), __main_block_copy_0, __main_block_dispose_0};
int main(int argc, const char * argv[]) {
    /* @autoreleasepool */ { __AtAutoreleasePool __autoreleasepool; 
        MJBlock block;

        {
            MJPerson *person = ((MJPerson *(*)(id, SEL))(void *)objc_msgSend)((id)((MJPerson *(*)(id, SEL))(void *)objc_msgSend)((id)objc_getClass("MJPerson"), sel_registerName("alloc")), sel_registerName("init"));
            ((void (*)(id, SEL, int))(void *)objc_msgSend)((id)person, sel_registerName("setAge:"), 10);


            int age = 10;
            block = ((void (*)())&__main_block_impl_0((void *)__main_block_func_0, &__main_block_desc_0_DATA, person, 570425344));
        }

        NSLog((NSString *)&__NSConstantStringImpl__var_folders_mm_hfgvs481081__0wdsw776zfh0000gn_T_main_13ee9c_mi_1);
    }
    return 0;
}

5.

typedef void (^MJBlock)(void);

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        MJBlock block;

        {
            MJPerson *person = [[MJPerson alloc] init];
            person.age = 10;

            __weak MJPerson *weakPerson = person;
            int age = 10;
            block = ^{
                NSLog(@"---------%d", weakPerson.age);
            };
        }

        NSLog(@"------");
    }
    return 0;
}

源码

typedef void (*MJBlock)(void);


struct __main_block_impl_0 {
  struct __block_impl impl;
  struct __main_block_desc_0* Desc;
  MJPerson *__weak weakPerson;
  __main_block_impl_0(void *fp, struct __main_block_desc_0 *desc, MJPerson *__weak _weakPerson, int flags=0) : weakPerson(_weakPerson) {
    impl.isa = &_NSConcreteStackBlock;
    impl.Flags = flags;
    impl.FuncPtr = fp;
    Desc = desc;
  }
};
static void __main_block_func_0(struct __main_block_impl_0 *__cself) {
  MJPerson *__weak weakPerson = __cself->weakPerson; // bound by copy

                NSLog((NSString *)&__NSConstantStringImpl__var_folders_mm_hfgvs481081__0wdsw776zfh0000gn_T_main_1cad2d_mi_0, ((int (*)(id, SEL))(void *)objc_msgSend)((id)weakPerson, sel_registerName("age")));
            }
static void __main_block_copy_0(struct __main_block_impl_0*dst, struct __main_block_impl_0*src) {_Block_object_assign((void*)&dst->weakPerson, (void*)src->weakPerson, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static void __main_block_dispose_0(struct __main_block_impl_0*src) {_Block_object_dispose((void*)src->weakPerson, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static struct __main_block_desc_0 {
  size_t reserved;
  size_t Block_size;
  void (*copy)(struct __main_block_impl_0*, struct __main_block_impl_0*);
  void (*dispose)(struct __main_block_impl_0*);
} __main_block_desc_0_DATA = { 0, sizeof(struct __main_block_impl_0), __main_block_copy_0, __main_block_dispose_0};
int main(int argc, const char * argv[]) {
    /* @autoreleasepool */ { __AtAutoreleasePool __autoreleasepool; 
        MJBlock block;

        {
            MJPerson *person = ((MJPerson *(*)(id, SEL))(void *)objc_msgSend)((id)((MJPerson *(*)(id, SEL))(void *)objc_msgSend)((id)objc_getClass("MJPerson"), sel_registerName("alloc")), sel_registerName("init"));
            ((void (*)(id, SEL, int))(void *)objc_msgSend)((id)person, sel_registerName("setAge:"), 10);

            __attribute__((objc_ownership(weak))) MJPerson *weakPerson = person;
            int age = 10;
            block = ((void (*)())&__main_block_impl_0((void *)__main_block_func_0, &__main_block_desc_0_DATA, weakPerson, 570425344));
        }

        NSLog((NSString *)&__NSConstantStringImpl__var_folders_mm_hfgvs481081__0wdsw776zfh0000gn_T_main_1cad2d_mi_1);
    }
    return 0;
}

6.


typedef void (^MJBlock)(void);

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        MJBlock block;

        {
            MJPerson *person = [[MJPerson alloc] init];
            person.age = 10;

            __weak MJPerson *weakPerson = person;
            block = ^{
                __strong MJPerson *strongPerson =weakPerson;
                NSLog(@"---------%d", strongPerson.age);
            };
        }

        NSLog(@"------");
    }
    return 0;
}

源码

typedef void (*MJBlock)(void);


struct __main_block_impl_0 {
  struct __block_impl impl;
  struct __main_block_desc_0* Desc;
  MJPerson *__weak weakPerson;
  __main_block_impl_0(void *fp, struct __main_block_desc_0 *desc, MJPerson *__weak _weakPerson, int flags=0) : weakPerson(_weakPerson) {
    impl.isa = &_NSConcreteStackBlock;
    impl.Flags = flags;
    impl.FuncPtr = fp;
    Desc = desc;
  }
};
static void __main_block_func_0(struct __main_block_impl_0 *__cself) {
  MJPerson *__weak weakPerson = __cself->weakPerson; // bound by copy

                __attribute__((objc_ownership(strong))) MJPerson *strongPerson =weakPerson;
                NSLog((NSString *)&__NSConstantStringImpl__var_folders_mm_hfgvs481081__0wdsw776zfh0000gn_T_main_47b66f_mi_0, ((int (*)(id, SEL))(void *)objc_msgSend)((id)strongPerson, sel_registerName("age")));
            }
static void __main_block_copy_0(struct __main_block_impl_0*dst, struct __main_block_impl_0*src) {_Block_object_assign((void*)&dst->weakPerson, (void*)src->weakPerson, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static void __main_block_dispose_0(struct __main_block_impl_0*src) {_Block_object_dispose((void*)src->weakPerson, 3/*BLOCK_FIELD_IS_OBJECT*/);}

static struct __main_block_desc_0 {
  size_t reserved;
  size_t Block_size;
  void (*copy)(struct __main_block_impl_0*, struct __main_block_impl_0*);
  void (*dispose)(struct __main_block_impl_0*);
} __main_block_desc_0_DATA = { 0, sizeof(struct __main_block_impl_0), __main_block_copy_0, __main_block_dispose_0};
int main(int argc, const char * argv[]) {
    /* @autoreleasepool */ { __AtAutoreleasePool __autoreleasepool; 
        MJBlock block;

        {
            MJPerson *person = ((MJPerson *(*)(id, SEL))(void *)objc_msgSend)((id)((MJPerson *(*)(id, SEL))(void *)objc_msgSend)((id)objc_getClass("MJPerson"), sel_registerName("alloc")), sel_registerName("init"));
            ((void (*)(id, SEL, int))(void *)objc_msgSend)((id)person, sel_registerName("setAge:"), 10);

            __attribute__((objc_ownership(weak))) MJPerson *weakPerson = person;
            block = ((void (*)())&__main_block_impl_0((void *)__main_block_func_0, &__main_block_desc_0_DATA, weakPerson, 570425344));
        }

        NSLog((NSString *)&__NSConstantStringImpl__var_folders_mm_hfgvs481081__0wdsw776zfh0000gn_T_main_47b66f_mi_1);
    }
    return 0;
}

7.
©著作权归作者所有,转载或内容合作请联系作者
  • 人面猴
    序言：七十年代末，一起剥皮案震惊了整个滨河市，随后出现的几起案子，更是在滨河造成了极大的恐慌，老刑警刘岩，带你破解...
    沈念sama阅读 206,839评论 6赞 482
  • 死咒
    序言：滨河连续发生了三起死亡事件，死亡现场离奇诡异，居然都是意外死亡，警方通过查阅死者的电脑和手机，发现死者居然都...
    沈念sama阅读 88,543评论 2赞 382
  • 救了他两次的神仙让他今天三更去死
    文/潘晓璐 我一进店门，熙熙楼的掌柜王于贵愁眉苦脸地迎上来，“玉大人，你说我怎么就摊上这事。” “怎么了？”我有些...
    开封第一讲书人阅读 153,116评论 0赞 344
  • 道士缉凶录：失踪的卖姜人
    文/不坏的土叔 我叫张陵，是天一观的道长。 经常有香客问我，道长，这世上最难降的妖魔是什么？ 我笑而不...
    开封第一讲书人阅读 55,371评论 1赞 279
  • 港岛之恋（遗憾婚礼）
    正文 为了忘掉前任，我火速办了婚礼，结果婚礼上，老公的妹妹穿的比我还像新娘。我一直安慰自己，他们只是感情好，可当我...
    茶点故事阅读 64,384评论 5赞 374
  • 恶毒庶女顶嫁案：这布局不是一般人想出来的
    文/花漫 我一把揭开白布。 她就那样静静地躺着，像睡着了一般。 火红的嫁衣衬着肌肤如雪。 梳的纹丝不乱的头发上，一...
    开封第一讲书人阅读 49,111评论 1赞 285
  • 城市分裂传说
    那天，我揣着相机与录音，去河边找鬼。 笑死，一个胖子当着我的面吹牛，可吹牛的内容都是我干的。 我是一名探鬼主播，决...
    沈念sama阅读 38,416评论 3赞 400
  • 双鸳鸯连环套：你想象不到人心有多黑
    文/苍兰香墨 我猛地睁开眼，长吁一口气：“原来是场噩梦啊……” “哼！你这毒妇竟也来了？” 一声冷哼从身侧响起，我...
    开封第一讲书人阅读 37,053评论 0赞 259
  • 万荣杀人案实录
    序言：老挝万荣一对情侣失踪，失踪者是张志新（化名）和其女友刘颖，没想到半个月后，有当地人在树林里发现了一具尸体，经...
    沈念sama阅读 43,558评论 1赞 300
  • 护林员之死
    正文 独居荒郊野岭守林人离奇死亡，尸身上长有42处带血的脓包…… 初始之章·张勋 以下内容为张勋视角 年9月15日...
    茶点故事阅读 36,007评论 2赞 325
  • 白月光启示录
    正文 我和宋清朗相恋三年，在试婚纱的时候发现自己被绿了。 大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
    茶点故事阅读 38,117评论 1赞 334
  • 活死人
    序言：一个原本活蹦乱跳的男人离奇死亡，死状恐怖，灵堂内的尸体忽然破棺而出，到底是诈尸还是另有隐情，我是刑警宁泽，带...
    沈念sama阅读 33,756评论 4赞 324
  • 日本核电站爆炸内幕
    正文 年R本政府宣布，位于F岛的核电站，受9级特大地震影响，放射性物质发生泄漏。R本人自食恶果不足惜，却给世界环境...
    茶点故事阅读 39,324评论 3赞 307
  • 男人毒药：我在死后第九天来索命
    文/蒙蒙 一、第九天 我趴在偏房一处隐蔽的房顶上张望。 院中可真热闹，春花似锦、人声如沸。这庄子的主人今日做“春日...
    开封第一讲书人阅读 30,315评论 0赞 19
  • 一桩弑父案，背后竟有这般阴谋
    文/苍兰香墨 我抬头看了看天上的太阳。三九已至，却和暖如春，着一层夹袄步出监牢的瞬间，已是汗流浃背。 一阵脚步声响...
    开封第一讲书人阅读 31,539评论 1赞 262
  • 情欲美人皮
    我被黑心中介骗来泰国打工， 没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留，地道东北人。 一个月前我还...
    沈念sama阅读 45,578评论 2赞 355
  • 代替公主和亲
    正文 我出身青楼，却偏偏与公主长得像，于是被迫代替她去往敌国和亲。 传闻我的和亲对象是个残疾皇子，可洞房花烛夜当晚...
    茶点故事阅读 42,877评论 2赞 345

推荐阅读更多精彩内容