test/lazyClassName.m

   1 /*
   2 TEST_RUN_OUTPUT
   3 LazyClassName
   4 LazyClassName2
   5 END
   6 */
   7
   8 #include "test.h"
   9 #include "testroot.i"
  10
  11 typedef const char * _Nullable (*objc_hook_lazyClassNamer)(_Nonnull Class);
  12
  13 void objc_setHook_lazyClassNamer(_Nonnull objc_hook_lazyClassNamer newValue,
  14                                   _Nonnull objc_hook_lazyClassNamer * _Nonnull oldOutValue);
  15
  16 #define RW_COPIED_RO          (1<<27)
  17
  18 struct ObjCClass {
  19     struct ObjCClass * __ptrauth_objc_isa_pointer isa;
  20     struct ObjCClass * __ptrauth_objc_super_pointer superclass;
  21     void *cachePtr;
  22     uintptr_t zero;
  23     uintptr_t data;
  24 };
  25
  26 struct ObjCClass_ro {
  27     uint32_t flags;
  28     uint32_t instanceStart;
  29     uint32_t instanceSize;
  30 #ifdef __LP64__
  31     uint32_t reserved;
  32 #endif
  33
  34     union {
  35         const uint8_t * ivarLayout;
  36         struct ObjCClass * nonMetaClass;
  37     };
  38
  39     const char * name;
  40     struct ObjCMethodList * __ptrauth_objc_method_list_pointer baseMethodList;
  41     struct protocol_list_t * baseProtocols;
  42     const struct ivar_list_t * ivars;
  43
  44     const uint8_t * weakIvarLayout;
  45     struct property_list_t *baseProperties;
  46 };
  47
  48 extern struct ObjCClass OBJC_METACLASS_$_NSObject;
  49 extern struct ObjCClass OBJC_CLASS_$_NSObject;
  50
  51 extern struct ObjCClass LazyClassName;
  52 extern struct ObjCClass LazyClassName2;
  53
  54 struct ObjCClass_ro LazyClassNameMetaclass_ro = {
  55     .flags = 1,
  56     .instanceStart = 40,
  57     .instanceSize = 40,
  58     .nonMetaClass = &LazyClassName,
  59 };
  60
  61 struct ObjCClass LazyClassNameMetaclass = {
  62     .isa = &OBJC_METACLASS_$_NSObject,
  63     .superclass = &OBJC_METACLASS_$_NSObject,
  64     .cachePtr = &_objc_empty_cache,
  65     .data = (uintptr_t)&LazyClassNameMetaclass_ro,
  66 };
  67
  68 struct ObjCClass_ro LazyClassName_ro = {
  69     .instanceStart = 8,
  70     .instanceSize = 8,
  71 };
  72
  73 struct ObjCClass LazyClassName = {
  74     .isa = &LazyClassNameMetaclass,
  75     .superclass = &OBJC_CLASS_$_NSObject,
  76     .cachePtr = &_objc_empty_cache,
  77     .data = (uintptr_t)&LazyClassName_ro + 2,
  78 };
  79
  80 struct ObjCClass_ro LazyClassName2Metaclass_ro = {
  81     .flags = 1,
  82     .instanceStart = 40,
  83     .instanceSize = 40,
  84     .nonMetaClass = &LazyClassName2,
  85 };
  86
  87 struct ObjCClass LazyClassName2Metaclass = {
  88     .isa = &OBJC_METACLASS_$_NSObject,
  89     .superclass = &OBJC_METACLASS_$_NSObject,
  90     .cachePtr = &_objc_empty_cache,
  91     .data = (uintptr_t)&LazyClassName2Metaclass_ro,
  92 };
  93
  94 struct ObjCClass_ro LazyClassName2_ro = {
  95     .instanceStart = 8,
  96     .instanceSize = 8,
  97 };
  98
  99 struct ObjCClass LazyClassName2 = {
 100     .isa = &LazyClassName2Metaclass,
 101     .superclass = &OBJC_CLASS_$_NSObject,
 102     .cachePtr = &_objc_empty_cache,
 103     .data = (uintptr_t)&LazyClassName2_ro + 2,
 104 };
 105
 106 static objc_hook_lazyClassNamer OrigNamer;
 107
 108 static const char *ClassNamer(Class cls) {
 109     if (cls == (__bridge Class)&LazyClassName)
 110         return "LazyClassName";
 111     return OrigNamer(cls);
 112 }
 113
 114 static objc_hook_lazyClassNamer OrigNamer2;
 115
 116 static const char *ClassNamer2(Class cls) {
 117     if (cls == (__bridge Class)&LazyClassName2)
 118         return "LazyClassName2";
 119     return OrigNamer2(cls);
 120 }
 121
 122 __attribute__((section("__DATA,__objc_classlist,regular,no_dead_strip")))
 123 struct ObjCClass *LazyClassNamePtr = &LazyClassName;
 124 __attribute__((section("__DATA,__objc_classlist,regular,no_dead_strip")))
 125 struct ObjCClass *LazyClassNamePtr2 = &LazyClassName2;
 126
 127 int main() {
 128 #pragma clang diagnostic push
 129 #pragma clang diagnostic ignored "-Wunguarded-availability"
 130     objc_setHook_lazyClassNamer(ClassNamer, &OrigNamer);
 131     objc_setHook_lazyClassNamer(ClassNamer2, &OrigNamer2);
 132 #pragma clang diagnostic pop
 133
 134     printf("%s\n", class_getName([(__bridge id)&LazyClassName class]));
 135     printf("%s\n", class_getName([(__bridge id)&LazyClassName2 class]));
 136 }