test/nonpointerisa.m

   1 // TEST_CFLAGS -framework Foundation
   2 // TEST_CONFIG MEM=mrc
   3
   4 #include "test.h"
   5 #include <dlfcn.h>
   6
   7 #include <objc/objc-gdb.h>
   8 #include <Foundation/Foundation.h>
   9
  10 #define ISA(x) (*((uintptr_t *)(x)))
  11 #define NONPOINTER(x) (ISA(x) & 1)
  12
  13 #if SUPPORT_NONPOINTER_ISA
  14 # if __x86_64__
  15 #   define RC_ONE (1ULL<<56)
  16 # elif __arm64__ && __LP64__
  17 // Quiet the warning about redefining the macro from isa.h.
  18 #   undef RC_ONE
  19 #   define RC_ONE (objc_debug_isa_magic_value == 1 ? 1ULL<<56 : 1ULL<<45)
  20 # elif __ARM_ARCH_7K__ >= 2  ||  (__arm64__ && !__LP64__)
  21 #   define RC_ONE (1ULL<<25)
  22 # else
  23 #   error unknown architecture
  24 # endif
  25 #endif
  26
  27
  28 void check_raw_pointer(id obj, Class cls)
  29 {
  30     testassert(object_getClass(obj) == cls);
  31     testassert(!NONPOINTER(obj));
  32
  33     uintptr_t isa = ISA(obj);
  34     testassertequal(ptrauth_strip((void *)isa, ptrauth_key_process_independent_data), (void *)cls);
  35     testassertequal((Class)(isa & objc_debug_isa_class_mask), cls);
  36     testassertequal(ptrauth_strip((void *)(isa & ~objc_debug_isa_class_mask), ptrauth_key_process_independent_data), 0);
  37
  38     CFRetain(obj);
  39     testassert(ISA(obj) == isa);
  40     testassert([obj retainCount] == 2);
  41     [obj retain];
  42     testassert(ISA(obj) == isa);
  43     testassert([obj retainCount] == 3);
  44     CFRelease(obj);
  45     testassert(ISA(obj) == isa);
  46     testassert([obj retainCount] == 2);
  47     [obj release];
  48     testassert(ISA(obj) == isa);
  49     testassert([obj retainCount] == 1);
  50 }
  51
  52
  53 #if ! SUPPORT_NONPOINTER_ISA
  54
  55 int main()
  56 {
  57 #if OBJC_HAVE_NONPOINTER_ISA  ||  OBJC_HAVE_PACKED_NONPOINTER_ISA  ||  OBJC_HAVE_INDEXED_NONPOINTER_ISA
  58 #   error wrong
  59 #endif
  60
  61     testprintf("Isa with index\n");
  62     id index_o = [NSObject new];
  63     check_raw_pointer(index_o, [NSObject class]);
  64
  65     // These variables DO NOT exist without non-pointer isa support.
  66     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_packed_isa_class_mask"));
  67     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_magic_mask"));
  68     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_magic_value"));
  69     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_index_mask"));
  70     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_index_shift"));
  71
  72     // These variables DO exist even without non-pointer isa support.
  73     testassert(dlsym(RTLD_DEFAULT, "objc_debug_isa_class_mask"));
  74     testassert(dlsym(RTLD_DEFAULT, "objc_debug_isa_magic_mask"));
  75     testassert(dlsym(RTLD_DEFAULT, "objc_debug_isa_magic_value"));
  76
  77     succeed(__FILE__);
  78 }
  79
  80 #else
  81 // SUPPORT_NONPOINTER_ISA
  82
  83 void check_nonpointer(id obj, Class cls)
  84 {
  85     testassertequal(object_getClass(obj), cls);
  86     testassert(NONPOINTER(obj));
  87
  88     uintptr_t isa = ISA(obj);
  89
  90     if (objc_debug_indexed_isa_magic_mask != 0) {
  91         // Indexed isa.
  92         testassertequal((isa & objc_debug_indexed_isa_magic_mask), objc_debug_indexed_isa_magic_value);
  93         testassert((isa & ~objc_debug_indexed_isa_index_mask) != 0);
  94         uintptr_t index = (isa & objc_debug_indexed_isa_index_mask) >> objc_debug_indexed_isa_index_shift;
  95         testassert(index < objc_indexed_classes_count);
  96         testassertequal(objc_indexed_classes[index], cls);
  97     } else {
  98         // Packed isa.
  99         testassertequal((Class)(isa & objc_debug_isa_class_mask), cls);
 100         testassert((Class)(isa & ~objc_debug_isa_class_mask) != 0);
 101         testassertequal((isa & objc_debug_isa_magic_mask), objc_debug_isa_magic_value);
 102     }
 103
 104     CFRetain(obj);
 105     testassertequal(ISA(obj), isa + RC_ONE);
 106     testassertequal([obj retainCount], 2);
 107     [obj retain];
 108     testassertequal(ISA(obj), isa + RC_ONE*2);
 109     testassertequal([obj retainCount], 3);
 110     CFRelease(obj);
 111     testassertequal(ISA(obj), isa + RC_ONE);
 112     testassertequal([obj retainCount], 2);
 113     [obj release];
 114     testassertequal(ISA(obj), isa);
 115     testassertequal([obj retainCount], 1);
 116 }
 117
 118
 119 @interface Fake_OS_object : NSObject {
 120     int refcnt;
 121     int xref_cnt;
 122 }
 123 @end
 124
 125 @implementation Fake_OS_object
 126 +(void)initialize {
 127     static bool initialized;
 128     if (!initialized) {
 129         initialized = true;
 130         testprintf("Nonpointer during +initialize\n");
 131         testassert(!NONPOINTER(self));
 132         id o = [Fake_OS_object new];
 133         check_nonpointer(o, self);
 134         [o release];
 135     }
 136 }
 137 @end
 138
 139 @interface Sub_OS_object : NSObject @end
 140
 141 @implementation Sub_OS_object
 142 @end
 143
 144
 145
 146 int main()
 147 {
 148     Class OS_object = objc_getClass("OS_object");
 149     class_setSuperclass([Sub_OS_object class], OS_object);
 150
 151     uintptr_t isa;
 152
 153 #if SUPPORT_PACKED_ISA
 154 # if !OBJC_HAVE_NONPOINTER_ISA  ||  !OBJC_HAVE_PACKED_NONPOINTER_ISA  ||  OBJC_HAVE_INDEXED_NONPOINTER_ISA
 155 #   error wrong
 156 # endif
 157     void *absoluteMask = (void *)&objc_absolute_packed_isa_class_mask;
 158 #if __has_feature(ptrauth_calls)
 159     absoluteMask = ptrauth_strip(absoluteMask, ptrauth_key_process_independent_data);
 160 #endif
 161     // absoluteMask should "cover" objc_debug_isa_class_mask
 162     testassert((objc_debug_isa_class_mask & (uintptr_t)absoluteMask) == objc_debug_isa_class_mask);
 163     // absoluteMask should only possibly differ in the high bits
 164     testassert((objc_debug_isa_class_mask & 0xffff) == ((uintptr_t)absoluteMask & 0xffff));
 165
 166     // Indexed isa variables DO NOT exist on packed-isa platforms
 167     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_magic_mask"));
 168     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_magic_value"));
 169     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_index_mask"));
 170     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_indexed_isa_index_shift"));
 171
 172 #elif SUPPORT_INDEXED_ISA
 173 # if !OBJC_HAVE_NONPOINTER_ISA  ||  OBJC_HAVE_PACKED_NONPOINTER_ISA  ||  !OBJC_HAVE_INDEXED_NONPOINTER_ISA
 174 #   error wrong
 175 # endif
 176     testassert(objc_debug_indexed_isa_magic_mask == (uintptr_t)&objc_absolute_indexed_isa_magic_mask);
 177     testassert(objc_debug_indexed_isa_magic_value == (uintptr_t)&objc_absolute_indexed_isa_magic_value);
 178     testassert(objc_debug_indexed_isa_index_mask == (uintptr_t)&objc_absolute_indexed_isa_index_mask);
 179     testassert(objc_debug_indexed_isa_index_shift == (uintptr_t)&objc_absolute_indexed_isa_index_shift);
 180
 181     // Packed isa variable DOES NOT exist on indexed-isa platforms.
 182     testassert(!dlsym(RTLD_DEFAULT, "objc_absolute_packed_isa_class_mask"));
 183
 184 #else
 185 #   error unknown nonpointer isa format
 186 #endif
 187
 188     testprintf("Isa with index\n");
 189     id index_o = [Fake_OS_object new];
 190     check_nonpointer(index_o, [Fake_OS_object class]);
 191
 192     testprintf("Weakly referenced\n");
 193     isa = ISA(index_o);
 194     id weak;
 195     objc_storeWeak(&weak, index_o);
 196     testassert(__builtin_popcountl(isa ^ ISA(index_o)) == 1);
 197
 198     testprintf("Has associated references\n");
 199     id assoc = @"thing";
 200     isa = ISA(index_o);
 201     objc_setAssociatedObject(index_o, assoc, assoc, OBJC_ASSOCIATION_ASSIGN);
 202     testassert(__builtin_popcountl(isa ^ ISA(index_o)) == 1);
 203
 204     testprintf("Isa without index\n");
 205     id raw_o = [OS_object alloc];
 206     check_raw_pointer(raw_o, [OS_object class]);
 207
 208
 209     id buf[4];
 210     id bufo = (id)buf;
 211
 212     testprintf("Change isa 0 -> raw pointer\n");
 213     bzero(buf, sizeof(buf));
 214     object_setClass(bufo, [OS_object class]);
 215     check_raw_pointer(bufo, [OS_object class]);
 216
 217     testprintf("Change isa 0 -> nonpointer\n");
 218     bzero(buf, sizeof(buf));
 219     object_setClass(bufo, [NSObject class]);
 220     check_nonpointer(bufo, [NSObject class]);
 221
 222     testprintf("Change isa nonpointer -> nonpointer\n");
 223     testassert(NONPOINTER(bufo));
 224     _objc_rootRetain(bufo);
 225     testassert(_objc_rootRetainCount(bufo) == 2);
 226     object_setClass(bufo, [Fake_OS_object class]);
 227     testassert(_objc_rootRetainCount(bufo) == 2);
 228     _objc_rootRelease(bufo);
 229     testassert(_objc_rootRetainCount(bufo) == 1);
 230     check_nonpointer(bufo, [Fake_OS_object class]);
 231
 232     testprintf("Change isa nonpointer -> raw pointer\n");
 233     // Retain count must be preserved.
 234     // Use root* to avoid OS_object's overrides.
 235     testassert(NONPOINTER(bufo));
 236     _objc_rootRetain(bufo);
 237     testassert(_objc_rootRetainCount(bufo) == 2);
 238     object_setClass(bufo, [OS_object class]);
 239     testassert(_objc_rootRetainCount(bufo) == 2);
 240     _objc_rootRelease(bufo);
 241     testassert(_objc_rootRetainCount(bufo) == 1);
 242     check_raw_pointer(bufo, [OS_object class]);
 243
 244     testprintf("Change isa raw pointer -> nonpointer (doesn't happen)\n");
 245     testassert(!NONPOINTER(bufo));
 246     _objc_rootRetain(bufo);
 247     testassert(_objc_rootRetainCount(bufo) == 2);
 248     object_setClass(bufo, [Fake_OS_object class]);
 249     testassert(_objc_rootRetainCount(bufo) == 2);
 250     _objc_rootRelease(bufo);
 251     testassert(_objc_rootRetainCount(bufo) == 1);
 252     check_raw_pointer(bufo, [Fake_OS_object class]);
 253
 254     testprintf("Change isa raw pointer -> raw pointer\n");
 255     testassert(!NONPOINTER(bufo));
 256     _objc_rootRetain(bufo);
 257     testassert(_objc_rootRetainCount(bufo) == 2);
 258     object_setClass(bufo, [Sub_OS_object class]);
 259     testassert(_objc_rootRetainCount(bufo) == 2);
 260     _objc_rootRelease(bufo);
 261     testassert(_objc_rootRetainCount(bufo) == 1);
 262     check_raw_pointer(bufo, [Sub_OS_object class]);
 263
 264
 265     succeed(__FILE__);
 266 }
 267
 268 // SUPPORT_NONPOINTER_ISA
 269 #endif