{"id":845,"date":"2019-06-28T23:20:34","date_gmt":"2019-06-28T15:20:34","guid":{"rendered":"https:\/\/flandre-scarlet.moe\/blog\/?p=845"},"modified":"2020-08-15T19:42:47","modified_gmt":"2020-08-15T11:42:47","slug":"c-%e7%a8%8b%e5%ba%8f%e7%9a%84%e9%80%86%e5%90%91%e5%88%86%e6%9e%90%e4%bb%a5%e5%8f%8a-rtti-%e4%bf%a1%e6%81%af%e6%a3%80%e7%b4%a2","status":"publish","type":"post","link":"https:\/\/flandre-scarlet.moe\/blog\/845\/","title":{"rendered":"C++ \u7a0b\u5e8f\u7684\u9006\u5411\u5206\u6790\u4ee5\u53ca RTTI \u4fe1\u606f\u68c0\u7d22"},"content":{"rendered":"

\u5206\u6790 C++ \u7a0b\u5e8f\u65f6\uff0c\u8981\u662f\u80fd\u4ece\u4e00\u4e2a\u4e8c\u8fdb\u5236\u6587\u4ef6\u4e2d\u8bc6\u522b\u51fa C++ \u7a0b\u5e8f\u7684\u7ed3\u6784\uff0c\u5e76\u4e14\u80fd\u6807\u8bc6\u51fa\u4e00\u4e9b\u4e3b\u8981\u7684\u7c7b\u548c\u5b83\u4eec\u7684\u5173\u7cfb\u662f\u975e\u5e38\u6709\u5e2e\u52a9\u7684\u3002\u800c\u5176\u4e2d\u4e3a\u4e86\u5b9e\u73b0\u8fd0\u884c\u65f6\u7c7b\u578b\u8bc6\u522b\u800c\u751f\u6210\u7684\u8fd0\u884c\u65f6\u7c7b\u578b\u4fe1\u606f\uff08Runtime type information\uff0cRTTI\uff09\u4e5f\u80fd\u5728\u7a0b\u5e8f\u5206\u6790\u4e0a\u63d0\u4f9b\u65b9\u4fbf\u3002<\/p>\n

\u6ce8\u610f\uff0c\u6587\u4e2d\u8ba8\u8bba\u7684 C++ \u53ef\u6267\u884c\u6587\u4ef6\u4ec5\u9650\u4e8e\u4f7f\u7528 MSVC \u7f16\u8bd1\u5668\u7f16\u8bd1\u51fa\u7684 C++ \u53ef\u6267\u884c\u6587\u4ef6\u3002<\/p>\n

\u25cf\u8bc6\u522b\u7c7b\u53ca\u5176\u6784\u9020\u51fd\u6570<\/h1>\n

<\/p>\n

    \n
  1. \u51fd\u6570\u4e2d\u591a\u5904\u4f7f\u7528 ecx \u5bc4\u5b58\u5668\u76f8\u5bf9\u5bfb\u5740\uff08this \u6307\u9488\uff0c\u4e5f\u53ef\u80fd\u4f1a\u6709\u5c06 ecx \u5b58\u81f3 ebx \u7b49\u5176\u4ed6\u5bc4\u5b58\u5668\u540e\u518d\u5f15\u7528\u7684\uff0c\u89c6\u5177\u4f53\u60c5\u51b5\uff09\uff0c\u53ef\u80fd\u662f\u5728\u8bfb\u5199\u7c7b\u7684\u6210\u5458\u53d8\u91cf\uff0c\u4e0d\u8fc7\u8fd9\u4e00\u70b9\u5e76\u4e0d\u662f\u7279\u522b\u51c6\u786e\uff0c\u7279\u522b\u5f53\u8bfb\u5199\u6808\u4e0a\u7684\u5c40\u90e8\u7c7b\u5b9e\u4f8b\u65f6\uff0c\u7ecf\u8fc7\u4f18\u5316\u7684\u4ee3\u7801\u4e0d\u592a\u5bb9\u6613\u76f4\u63a5\u770b\u51fa\u51e0\u4e2a\u5185\u5b58\u53d8\u91cf\u4e4b\u95f4\u7684\u76f8\u5173\u6027\u3002<\/li>\n
  2. \u901a\u8fc7 thiscall \u7684\u8c03\u7528\u7ea6\u5b9a\u3002thiscall \u4f7f\u7528 ecx \u4f20\u9012 this \u6307\u9488\uff0c\u56e0\u6b64\u78b0\u5230\u6709\u4e3a ecx \u8d4b\u503c\u540e\u7d27\u63a5\u7740\u8c03\u7528\u51fd\u6570\u7684\u60c5\u51b5\uff0c\u57fa\u672c\u786e\u5b9a\u662f\u5728\u8c03\u7528\u67d0\u4e2a\u7c7b\u6210\u5458\u51fd\u6570\uff0c\u5f53\u7136\u4e5f\u6709\u53ef\u80fd\u662f\u4e2a fastcall \u7684\u51fd\u6570\uff1b\u7279\u522b\u7684\uff0c\u5982\u679c\u53d1\u73b0 ecx \u5f15\u7528\u4e86\u4e00\u4e2a\u672a\u521d\u59cb\u5316\u8fc7\u7684\u5730\u5740\uff0c\u6bd4\u5982\u8bf4\u6808\u4e0a\u7684\uff0c\u90a3\u8c03\u7528\u7684\u5f88\u6709\u53ef\u80fd\u5c31\u662f\u5c40\u90e8\u7c7b\u53d8\u91cf\u7684\u6784\u9020\u51fd\u6570\u3002\u540c\u6837\uff0cnew \u8fd4\u56de\u540e\u7684 eax \u76f4\u63a5\u6254\u7ed9 ecx \u518d\u8c03\u7528\u51fd\u6570\uff0c\u4e5f\u6781\u6709\u53ef\u80fd\u662f\u5728\u8c03\u7528\u6784\u9020\u51fd\u6570\u3002<\/li>\n
  3. \u901a\u8fc7\u95f4\u63a5\u51fd\u6570\u8c03\u7528\uff0c\u9047\u5230\u5f62\u5982\n
    \r\n    mov  eax,dword ptr [ecx]\r\n    mov  eax,dword ptr [eax+18h]\r\n    call eax<\/pre>\n
    \u4e09\u8fde\u7684\u8bdd\u57fa\u672c\u4e5f\u53ef\u4ee5\u786e\u5b9a\u662f\u5728\u8c03\u7528\u7c7b\u7684\u865a\u51fd\u6570\u3002\u9047\u5230\u865a\u51fd\u6570\u7684\u8bdd\uff0c\u53ea\u80fd\u901a\u8fc7 this \u6307\u9488\u627e\u5230\u865a\u8868\u7136\u540e\u786e\u5b9a\u5b9e\u9645\u8c03\u7528\u7684\u51fd\u6570\u4e86\uff0c\u663e\u7136\u65e0\u6cd5\u8fdb\u884c\u9759\u6001\u5206\u6790\u3002<\/li>\n
  4. \u591a\u6001\u7c7b\u5728\u8c03\u7528\u4e86\u57fa\u7c7b\u7684\u6784\u9020\u51fd\u6570\u540e\uff0c\u6267\u884c\u540e\u7eed\u4ee3\u7801\u524d\u4f1a\u8bbe\u7f6e\u8be5\u7c7b\u81ea\u5df1\u7684\u865a\u8868\uff0c\u5373\u5f15\u7528\u4e00\u4e2a\u4f4d\u4e8e .rdata \u6bb5\u91cc\u7684\u5168\u5c40\u5730\u5740\uff0c\u5e38\u4f1a\u6709\u5f62\u5982\n
    mov dword ptr [eax], offset 72C20C<\/pre>\n
    \u8fd9\u6837\u7684\u4ee3\u7801\u51fa\u73b0\uff0c\u540e\u8005\u662f\u4e00\u4e2a\u53ea\u8bfb\u7684\u5730\u5740\uff0c\u5c31\u53ef\u80fd\u662f\u5728\u8bbe\u7f6e\u865a\u8868\u3002\u5f53\u7136\uff0c\u67e5\u770b\u8be5\u5730\u5740\u4e2d\u7684\u6bcf\u4e2a\u6307\u9488\u5e94\u5f53\u90fd\u662f\u6307\u5411\u5230\u4ee3\u7801\u6bb5\u4e2d\u7684\u3002\u6790\u6784\u51fd\u6570\u4e2d\u4e5f\u4f1a\u51fa\u73b0\u7c7b\u4f3c\u64cd\u4f5c\u3002<\/li>\n<\/ol>\n
    \u25cf\u7c7b\u7684\u5185\u5b58\u5e03\u5c40<\/h1>\n
    \u5173\u4e8e\u7c7b\u7ee7\u627f\u5e03\u5c40\u5728\u6211\u4e4b\u524d\u7684\u4e00\u7bc7\u6587\u7ae0<\/a>\u91cc\u4e5f\u63d0\u5230\u8fc7\u3002<\/p>\n
    \u719f\u6089\u5e03\u5c40\u540e\u53ef\u4ee5\u65b9\u4fbf\u6211\u4eec\u786e\u5b9a\u7c7b\u4e0e\u7c7b\u95f4\u7684\u5173\u7cfb\u548c\u7c7b\u91cc\u7684\u6210\u5458\uff0c\u4f7f\u7528 MSVC \u7684 -d1reportSingleClassLayoutXXX<\/i> \u6216 -d1reportAllClassLayout \u547d\u4ee4\u53c2\u6570\u53ef\u4ee5\u663e\u793a\u4ee3\u7801\u4e2d\u5355\u4e2a\u6216\u6240\u6709\u7c7b\u7684\u5e03\u5c40\uff08\u5c06 XXX \u66ff\u6362\u6210\u7c7b\u540d\uff0c\u4e0d\u63d2\u5165\u7a7a\u683c\uff0c\u7f16\u8bd1\u5668\u4f1a\u663e\u793a\u51fa\u5305\u542b\u5173\u952e\u5b57 XXX \u7684\u6240\u6709\u7c7b\uff09\u3002\u5b9e\u9645\u9879\u76ee\u4e2d\u865a\u7ee7\u627f\u6211\u60f3\u5e94\u8be5\u4e0d\u4f1a\u592a\u591a\uff08\u4e5f\u53ef\u80fd\u53ea\u662f\u6211\u89c1\u7684\u5c11\u2026\u2026\uff09\uff0c\u4f46\u662f\u63a5\u53e3\u591a\u7ee7\u627f\u8fd8\u662f\u5f88\u5e38\u89c1\u7684\u3002\u8d34\u51e0\u4e2a\u4e0d\u540c\u7c7b\u578b\u7684\u7c7b\u5e03\u5c40\u4fe1\u606f\u3002<\/p>\n
    class Animal_01\r\n{\r\npublic:\r\n    virtual void fff01() {}\r\n};\r\nclass Animal_02\r\n{\r\npublic:\r\n    virtual void fff02() {}\r\n};\r\nclass Animal_11\r\n{\r\npublic:\r\n    virtual void fff11() {}\r\n};\r\nclass Animal_0 : public Animal_01, public Animal_02\r\n{\r\npublic:\r\n    virtual ~Animal_0() {}\r\n};\r\nclass Animal_1 : public Animal_11\r\n{\r\npublic:\r\n    virtual void A1() {}\r\n};\r\nclass Animal : virtual public Animal_1, virtual public Animal_0\r\n{\r\npublic:\r\n    virtual ~Animal(void) {}\r\n};<\/pre>\n
    \u5355\u7ee7\u627f<\/h3>\n
    class Animal_1 : public Animal_11<\/pre>\n
     class Animal_1\tsize(4):\r\n\t+---\r\n 0\t| +--- (base class Animal_11)\r\n 0\t| | {vfptr}\r\n\t| +---\r\n\t+---\r\n\r\nAnimal_1::$vftable@:\r\n\t| &Animal_1_meta\r\n\t|  0\r\n 0\t| &Animal_11::fff11\r\n 1\t| &Animal_1::A1<\/pre>\n
    \u591a\u7ee7\u627f<\/h3>\n
    class Animal_0 : public Animal_01, public Animal_02<\/pre>\n
     class Animal_0\tsize(8):\r\n\t+---\r\n 0\t| +--- (base class Animal_01)\r\n 0\t| | {vfptr}\r\n\t| +---\r\n 4\t| +--- (base class Animal_02)\r\n 4\t| | {vfptr}\r\n\t| +---\r\n\t+---\r\n\r\nAnimal_0::$vftable@Animal_01@:\r\n\t| &Animal_0_meta\r\n\t|  0\r\n 0\t| &Animal_01::fff01\r\n 1\t| &Animal_0::{dtor}\r\n\r\nAnimal_0::$vftable@Animal_02@:\r\n\t| -4\r\n 0\t| &Animal_02::fff02<\/pre>\n
    \u865a\u7ee7\u627f<\/h3>\n
    class Animal : virtual public Animal_1, virtual public Animal_0<\/pre>\n
     class Animal\tsize(16):\r\n\t+---\r\n 0\t| {vbptr}\r\n\t+---\r\n\t+--- (virtual base Animal_1)\r\n 4\t| +--- (base class Animal_11)\r\n 4\t| | {vfptr}\r\n\t| +---\r\n\t+---\r\n\t+--- (virtual base Animal_0)\r\n 8\t| +--- (base class Animal_01)\r\n 8\t| | {vfptr}\r\n\t| +---\r\n12\t| +--- (base class Animal_02)\r\n12\t| | {vfptr}\r\n\t| +---\r\n\t+---\r\n\r\nAnimal::$vbtable@:\r\n 0\t| 0\r\n 1\t| 4 (Animald(Animal+0)Animal_1)\r\n 2\t| 8 (Animald(Animal+0)Animal_0)\r\n\r\nAnimal::$vftable@:\r\n\t| -4\r\n 0\t| &Animal_11::fff11\r\n 1\t| &Animal_1::A1\r\n\r\nAnimal::$vftable@Animal_01@:\r\n\t| -8\r\n 0\t| &Animal_01::fff01\r\n 1\t| &Animal::{dtor}\r\n\r\nAnimal::$vftable@Animal_02@:\r\n\t| -12\r\n 0\t| &Animal_02::fff02<\/pre>\n
    \u25cf\u5229\u7528 RTTI \u4fe1\u606f\u8bc6\u522b C++ \u7c7b<\/h1>\n
    RTTI \u5bf9\u4e8e\u8bc6\u522b\u591a\u6001\u7c7b\u80fd\u63d0\u4f9b\u5f88\u591a\u5e2e\u52a9\uff0c\u53ef\u4ee5\u4e86\u89e3\u5230\u7c7b\u540d\u3001\u7c7b\u7684\u7ee7\u627f\u5173\u7cfb\u7b49\u4fe1\u606f\uff0c\u5f53\u7136\u975e\u591a\u6001\u7684\u7c7b\u662f\u6ca1\u6709\u8fd9\u4e1c\u897f\u7684\u3002VS \u7f16\u8bd1 C++ \u4ee3\u7801\u65f6\u9ed8\u8ba4\u542f\u7528 RTTI\uff0c\u5176\u8bbe\u7f6e\u9879\u5728\u201c\u9879\u76ee\u5c5e\u6027-C++-\u8bed\u8a00-\u542f\u7528\u8fd0\u884c\u65f6\u7c7b\u578b\u8bc6\u522b\u201d\u9009\u9879\u4e2d\uff0c\u5c06\u5176\u5173\u95ed\u540e\u4e5f\u5c31\u65e0\u6cd5\u518d\u4f7f\u7528 typeid \u548c dynamic_cast \u4e86\u3002<\/p>\n
    \u4e0b\u9762\u4ecb\u7ecd\u4e00\u4e0b\u76f8\u5173\u7684\u7ed3\u6784\u3002<\/p>\n
      \n
    1. RTTICompleteObjectLocator
      \n    \u8be5\u7ed3\u6784\u662f\u4ece this \u6307\u9488\u627e\u5230\u7684\u7b2c\u4e00\u4e2a\u7ed3\u6784\uff0c\u540e\u7eed\u7684\u7ed3\u6784\u5747\u53ef\u4ece\u5b83\u5f15\u51fa\u3002\u5185\u90e8\u5305\u542b\u4e86\u4e24\u4e2a\u6307\u9488\uff0c\u5206\u522b\u6307\u5411\u81ea\u8eab\u7684\u7c7b\u4fe1\u606f\u548c\u7c7b\u7684\u7ee7\u627f\u4fe1\u606f\u3002<\/p>\n
      \r\n+0  unsigned long                 signature;       \/\/ \u4f3c\u4e4e\u90fd\u662f 0\r\n+4  unsigned long                 offset;          \/\/ \u865a\u8868\u504f\u79fb\r\n+8  unsigned long                 cdOffset;        \/\/ ?\r\n+c  TypeDescriptor*               pTypeDescriptor; \/\/ \u81ea\u8eab\u7c7b\u4fe1\u606f\r\n+10 RTTIClassHierarchyDescriptor* pClassHierarchyDescriptor; \/\/ \u7c7b\u7684\u7ee7\u627f\u4fe1\u606f<\/pre>\n
          \u67e5\u627e\u7684\u65f6\u5019\u5148\u901a\u8fc7 this \u6307\u9488\u627e\u5230\u865a\u8868\uff0c\u7136\u540e\u865a\u8868\u5f80\u524d\u79fb\u52a8\u4e00\u4e2a uint32_t \u5c31\u662f\u6307\u5411\u8be5\u7ed3\u6784\u7684\u6307\u9488\u4e86\u3002\u5373\uff1a<\/p>\n
      RTTICompleteObjectLocator* ptr = (RTTICompleteObjectLocator*)(*(uint32_t**)this)[-1];<\/pre>\n
          \u4f46\u662f\u5728\u590d\u6742\u7ee7\u627f\u60c5\u51b5\u4e0b\u8be5\u8868\u8fbe\u5f0f\u4e2d\u7684 this \u9700\u8981\u7ecf\u8fc7\u8c03\u6574\u540e\u624d\u80fd\u6b63\u5e38\u5de5\u4f5c\uff0c\u6bd4\u5982\u540c\u65f6\u865a\u7ee7\u627f\u4e86\u4e24\u4e2a\u7c7b\uff0c\u90a3\u4e48\u6b64\u65f6 this \u6307\u5411\u7684\u7b2c\u4e00\u4e2a uint32_t \u662f\u865a\u57fa\u7c7b\u8868\u6307\u9488\u3002<\/li>\n
    2. TypeDescriptor
      \n    \u8be5\u7ed3\u6784\u5305\u542b\u4e86\u7c7b\u81ea\u8eab\u7684\u4fe1\u606f\uff0c\u6700\u4e3b\u8981\u5c31\u662f\u91cc\u9762\u7684\u5b57\u7b26\u4e32\u7c7b\u540d\u79f0<\/p>\n
      \r\n+0  void*           pVFTable;   \/\/ \u6307\u5411 type_info \u7684\u865a\u8868\r\n+4  unsigned long   spare;      \/\/ \u4fdd\u7559\r\n+8  char[1]         name;       \/\/ \u7c7b\u540d<\/pre>\n<\/li>\n
    3. RTTIClassHierarchyDescriptor
      \n    \u8be5\u7ed3\u6784\u4e3a\u7c7b\u7684\u7ee7\u627f\u4fe1\u606f\uff0c\u91cc\u9762\u542b\u6709\u4ece\u5f53\u524d\u7c7b\u5f00\u59cb\u7684\u5176\u6240\u6709\u7236\u7c7b<\/p>\n
      \r\n+0  unsigned long       signature;       \/\/ \u4f3c\u4e4e\u90fd\u662f 0\r\n+4  unsigned long       attributes;      \/\/ \u7b2c0\u4f4d\u7f6e1\u8868\u793a\u591a\u7ee7\u627f\uff0c\r\n                                         \/\/ \u7b2c1\u4f4d\u7f6e1\u8868\u793a\u865a\u7ee7\u627f\r\n+8  unsigned long       numBaseClasses;  \/\/ \u7236\u7c7b\u6570\u91cf\uff0c\u5305\u62ec\u81ea\u5df1\u5728\u5185\uff0c\u6240\u4ee5\u6570\u91cf\u52a01\r\n+c  RTTIBaseClassArray* pBaseClassArray; \/\/ \u7236\u7c7b\u7684\u6570\u7ec4<\/pre>\n
          \u8fd9\u4e2a\u6570\u7ec4\u4e2d\u591a\u7ee7\u627f\u7684\u7c7b\u4e5f\u4f1a\u4e00\u5e76\u5217\u51fa\uff0c\u9879\u7684\u987a\u5e8f\u662f\u6309\u7ee7\u627f\u6811\u4ee5\u6df1\u5ea6\u4f18\u5148\u7684\u65b9\u5f0f\u5c55\u793a\uff0c\u5982 C \u540c\u65f6\u7ee7\u627f\u4e86 A \u548c B\uff0cAB \u53c8\u5206\u522b\u7ee7\u627f\u81ea A1\u3001A2\u3001B1\u3001B2\uff0c\u90a3\u4e48\u6570\u7ec4\u4e2d\u5c31\u4f1a\u6709 EAA1A2BB1B2 \u4e03\u9879\uff0c\u540e\u9762\u7684\u4f8b\u5b50\u4e2d\u4e5f\u80fd\u770b\u5230\u3002
      \nRTTIBaseClassArray \u8fd9\u4e2a\u7ed3\u6784\u91cc\u9762\u662f\u5355\u7eaf\u7684\u5305\u542b\u4e00\u4e2a RTTIBaseClassDescriptor* \u6570\u7ec4<\/p>\n
      +0 RTTIBaseClassDescriptor* arrayOfBaseClassDescriptors[]<\/pre>\n<\/li>\n
    4. RTTIBaseClassDescriptor
      \n    \u8be5\u7ed3\u6784\u8bb0\u5f55\u4e86\u76f8\u5e94\u7236\u7c7b\u7684\u4fe1\u606f<\/p>\n
      \r\n+0  TypeDescriptor *pTypeDescriptor; \/\/ \u7236\u7c7b\u81ea\u8eab\u7684\u4fe1\u606f\r\n+4  unsigned long numContainedBases; \/\/ \u7236\u7c7b\u7684\u7236\u7c7b\u6570\u91cf\r\n+8  PMD where;\r\n    +0  unsigned long mdisp;         \/\/ \u6210\u5458\u504f\u79fb\r\n    +4  unsigned long pdisp;         \/\/ \u865a\u57fa\u7c7b\u8868\u5728\u7c7b\u4e2d\u7684\u504f\u79fb\uff0c\r\n                                     \/\/ \u5982\u679c\u662f -1 \u8bf4\u660e\u8be5\u7c7b\u4e0d\u662f\u5176\u865a\u57fa\u7c7b\r\n    +8  unsigned long vdisp;         \/\/ \u57fa\u7c7b\u5728\u865a\u57fa\u7c7b\u8868\u4e2d\u7684\u504f\u79fb\r\n+14 unsigned long attributes;        \/\/ \r\n+18 RTTIClassHierarchyDescriptor* pClassDescriptor; \/\/ \u7236\u7c7b\u7684\u7ee7\u627f\u4fe1\u606f<\/pre>\n
          PMD \u4e2d\u51e0\u4e2a\u503c\u4e3b\u8981\u7528\u4e8e\u8ba1\u7b97\u8be5\u7236\u7c7b\u5728\u5176\u5b50\u7c7b\u4e2d\u7684\u504f\u79fb\u4f4d\u7f6e\uff0c\u8ba1\u7b97\u65b9\u5f0f\u5982\u4e0b\uff1a<\/p>\n
          size_t offset = 0;\r\n    if (pmd.pdisp >= 0) {       \/\/ \u4e3a -1 \u5219\u8df3\u8fc7\r\n        offset = pmd.pdisp;\r\n        offset += *(__int32*)((char*)*(size_t*)((char*)pThis + offset)\r\n            + pmd.vdisp);    \/\/ \u5728\u865a\u57fa\u7c7b\u8868\u4e2d\u627e\u5230 vdisp \u504f\u79fb\u503c\r\n    }\r\n    offset += pmd.mdisp;<\/pre>\n<\/li>\n<\/ol>\n
          \u4e3e\u4e2a\u4f8b\u5b50\uff0c\u6bd4\u5982\u524d\u9762\u7684<\/p>\n
      class Animal : virtual public Animal1, virtual public Animal2 <\/pre>\n
      \u7684\u7ee7\u627f\u5e03\u5c40\uff0c\u540c\u65f6\u5f97\u5230 Animal1 \u7684 PMD \u4e3a { mdisp:0, pdisp:0, vdisp:4 }\uff0c\u90a3\u4e48\u901a\u8fc7 Animal \u7c7b\u7684 this \u5f97\u5230 Animal1 \u7684\u6b65\u9aa4\u4e3a<\/p>\n
        \n
      1. (size_t)this + pdisp \u5f97\u5230\u865a\u57fa\u7c7b\u8868\u5730\u5740 vbt<\/li>\n
      2. *(size_t*)(*(size_t*)vbt + vdisp) \u518d\u83b7\u5f97\u865a\u57fa\u7c7b\u8868\u4e2d\u7b2c\u4e8c\u9879 Animal1 \u7684\u504f\u79fb offset<\/li>\n
      3. \u6700\u540e (size_t)this + offset<\/li>\n<\/ol>\n
        \u5f97\u5230\u6700\u7ec8 offset \u7684\u503c\u4e3a 4\u3002\u4e0b\u9762\u7684\u5e03\u5c40\u548c\u524d\u9762\u5c55\u793a\u7684\u865a\u7ee7\u627f\u5e03\u5c40\u662f\u4e00\u6837\u7684\uff0c\u8fd9\u91cc\u91cd\u65b0\u8d34\u4e00\u4efd\u3002<\/p>\n
        \r\nclass Animal\tsize(16):\r\n    +---\r\n 0  | {vbptr}\r\n    +---\r\n    +--- (virtual base Animal_1)\r\n 4  | +--- (base class Animal_11)\r\n 4  | | {vfptr}\r\n    | +---\r\n    +---\r\n    +--- (virtual base Animal_0)\r\n 8  | +--- (base class Animal_01)\r\n 8  | | {vfptr}\r\n    | +---\r\n12  | +--- (base class Animal_02)\r\n12  | | {vfptr}\r\n    | +---\r\n    +---\r\n\r\nAnimal::$vbtable@:\r\n 0  | 0\r\n 1  | 4 (Animald(Animal+0)Animal_1)\r\n 2  | 8 (Animald(Animal+0)Animal_0)\r\n<\/pre>\n
        \u25cf\u4ece\u53ef\u6267\u884c\u6587\u4ef6\u4e2d\u63d0\u53d6 RTTI \u4fe1\u606f<\/h1>\n
        \u901a\u8fc7\u4ee5\u4e0a\u7684 RTTI \u89e3\u6790\uff0c\u6211\u5199\u4e86\u4e2a\u53ef\u4ee5\u627e\u51fa exe \u4e2d\u591a\u6001\u7c7b\u4fe1\u606f\u7684\u7a0b\u5e8f\uff0c\u7b80\u5355\u5217\u51fa\u4e86\u7c7b\u540d\u3001\u7ee7\u627f\u5173\u7cfb\u4ee5\u53ca\u5728\u6784\u9020\u51fd\u6570\u4e2d\u88ab\u5f15\u7528\u7684 RVA \u5730\u5740\u3002\u7a0b\u5e8f\u4e3b\u8981\u901a\u8fc7\u5339\u914d\u5b57\u7b26\u4e32 “.?AV” \u6765\u627e\u5230\u7c7b\u540d\uff0c\u5e76\u8bc6\u522b\u51fa\u76f8\u5e94\u7684 RTTI \u4fe1\u606f\uff0c\u6700\u540e\u5b9a\u4f4d\u51fa\u5f15\u7528\u4e86\u5bf9\u5e94\u865a\u8868\u7684\u51fd\u6570\u7684 RVA \u5730\u5740\u3002\u4ee3\u7801\u653e\u5728\u8fd9\u91cc<\/a>\u3002
        \n\u8d34\u4e00\u90e8\u5206\u8f93\u51fa\u7ed3\u679c\uff08\u540c\u6837\u4f7f\u7528\u4e0a\u9762\u7684 Animal* \u7ee7\u627f\u7ed3\u6784\uff09<\/p>\n
        ---------------------------------\r\n.?AVAnimal_11@@: \r\nbase classes: .?AVAnimal_11@@, \r\n\r\nreference in ctors(next instruction): 13c9c, \r\n\r\n---------------------------------\r\n.?AVAnimal_0@@: \r\nbase classes: .?AVAnimal_0@@, .?AVAnimal_01@@, .?AVAnimal_02@@, \r\n\r\nreference in ctors(next instruction): 13c2f, 1436c, 13c39, 14376, \r\n\r\n---------------------------------\r\n.?AVAnimal_1@@: \r\nbase classes: .?AVAnimal_1@@, .?AVAnimal_11@@, \r\n\r\nreference in ctors(next instruction): 13cf4, \r\n\r\n---------------------------------\r\n.?AVAnimal@@: \r\nbase classes: .?AVAnimal@@, .?AVAnimal_1@@, .?AVAnimal_11@@, .?AVAnimal_0@@, .?AVAnimal_01@@, .?AVAnimal_02@@, \r\n\r\nreference in ctors(next instruction): 13adb, 142f7, 13aed, 1430b, 13b00, 1431f, \r\n<\/pre>\n
        \u770b\u5230 Animal \u7c7b\u7684\u865a\u8868\u6709 6 \u5904\u5f15\u7528\uff0c\u800c Animal \u4e2d\u56e0\u4e3a\u7ee7\u627f\u5173\u7cfb\u542b\u6709 3 \u4e2a\u865a\u8868\uff0c\u6240\u4ee5\u5206\u522b\u5c31\u662f\u6784\u9020\u3001\u6790\u6784\u51fd\u6570\u5404\u5f15\u7528\u4e86 3 \u6b21\u3002\u800c Animal_11 \u548c Animal_1 \u7c7b\u6ca1\u6709\u5b9a\u4e49\u865a\u57fa\u7c7b\uff0c\u6240\u4ee5\u53ea\u6709\u6784\u9020\u51fd\u6570\u4e2d\u5f15\u7528\u7684 1 \u6b21\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
        \u5206\u6790 C++ \u7a0b\u5e8f\u65f6\uff0c\u8981\u662f\u80fd\u4ece\u4e00\u4e2a\u4e8c\u8fdb\u5236\u6587\u4ef6\u4e2d\u8bc6\u522b\u51fa C++ \u7a0b\u5e8f\u7684\u7ed3\u6784\uff0c\u5e76\u4e14\u80fd\u6807\u8bc6\u51fa\u4e00\u4e9b\u4e3b\u8981\u7684\u7c7b\u548c\u5b83\u4eec\u7684\u5173\u7cfb… <\/p>\n
        \u9605\u8bfb\u66f4\u591a<\/i><\/a><\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[7,118,117,37],"class_list":["post-845","post","type-post","status-publish","format-standard","hentry","category-reverse-engineering","tag-c","tag-msvc","tag-rtti","tag-windows"],"_links":{"self":[{"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/posts\/845","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/comments?post=845"}],"version-history":[{"count":1,"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/posts\/845\/revisions"}],"predecessor-version":[{"id":1395,"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/posts\/845\/revisions\/1395"}],"wp:attachment":[{"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/media?parent=845"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/categories?post=845"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/flandre-scarlet.moe\/blog\/wp-json\/wp\/v2\/tags?post=845"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}