test/accessors.m

   1 #import <Foundation/Foundation.h>
   2 #import <objc/runtime.h>
   3 #include "test.h"
   4
   5 extern id objc_getProperty(id self, SEL _cmd, ptrdiff_t offset, BOOL atomic);
   6 extern void objc_setProperty(id self, SEL _cmd, ptrdiff_t offset, id newValue, BOOL atomic, BOOL shouldCopy);
   7
   8 @interface Test : NSObject {
   9     NSString *_value;
  10     // _object is at the last optimized property offset
  11     id _object __attribute__((aligned(64)));
  12 }
  13 @property(readonly) Class class;
  14 @property(copy) NSString *value;
  15 @property(assign) id object;
  16 @end
  17
  18 typedef struct {
  19     id isa;
  20     NSString *_value;
  21     // _object is at the last optimized property offset
  22     id _object __attribute__((aligned(64)));
  23 } TestDefs;
  24
  25 @implementation Test
  26
  27 // Question:  why can't this code be automatically generated?
  28
  29 - (void)dealloc {
  30     self.value = nil;
  31     self.object = nil;
  32     [super dealloc];
  33 }
  34
  35 - (Class)class { return objc_getProperty(self, _cmd, 0, YES); }
  36
  37 - (NSString*)value { return (NSString*) objc_getProperty(self, _cmd, offsetof(TestDefs, _value), YES); }
  38 - (void)setValue:(NSString*)inValue { objc_setProperty(self, _cmd, offsetof(TestDefs, _value), inValue, YES, YES); }
  39
  40 - (id)object { return objc_getProperty(self, _cmd, offsetof(TestDefs, _object), YES); }
  41 - (void)setObject:(id)inObject { objc_setProperty(self, _cmd, offsetof(TestDefs, _object), inObject, YES, NO); }
  42
  43 - (NSString *)description {
  44     return [NSString stringWithFormat:@"value = %@, object = %@", self.value, self.object];
  45 }
  46
  47 @end
  48
  49 int main() {
  50     NSAutoreleasePool *pool = [NSAutoreleasePool new];
  51
  52     NSMutableString *value = [NSMutableString stringWithUTF8String:"test"];
  53     id object = [NSNumber numberWithInt:11];
  54     Test *t = [[Test new] autorelease];
  55     t.value = value;
  56     [value setString:@"yuck"];      // mutate the string.
  57     testassert(t.value != value);   // must copy, since it was mutable.
  58     testassert([t.value isEqualToString:@"test"]);
  59
  60     Class testClass = [Test class];
  61     Class cls = t.class;
  62     testassert(testClass == cls);
  63     cls = t.class;
  64     testassert(testClass == cls);
  65
  66     t.object = object;
  67     t.object = object;
  68
  69     // NSLog(@"t.object = %@, t.value = %@", t.object, t.value);
  70     // NSLog(@"t.object = %@, t.value = %@", t.object, t.value); // second call will optimized getters.
  71
  72     [pool drain];
  73
  74     succeed(__FILE__);
  75
  76     return 0;
  77 }