A bit of modernising

Circle/Circle-Info.plist

@@ -9,7 +9,7 @@
 	<key>CFBundleIconFile</key>
 	<string></string>
 	<key>CFBundleIdentifier</key>
-	<string>com.mikeash.${PRODUCT_NAME:rfc1034identifier}</string>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleName</key>

Circle/CircleIVarLayout.m

@@ -50,8 +50,25 @@
 
 
 // Dictionarys to cache the layout and classification of a class.
-static CFMutableDictionaryRef gLayoutCache;
-static CFMutableDictionaryRef gClassificationCache;
+
+static CFMutableDictionaryRef getClassificationCache() {
+    static CFMutableDictionaryRef gClassificationCache;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        // When the layout cache doesn't exist, create it now. We'll be adding an entry.
+        gClassificationCache = CFDictionaryCreateMutable(NULL, 0, NULL, NULL);
+    });
+    return gClassificationCache;
+}
+static CFMutableDictionaryRef getLayoutCache() {
+    static dispatch_once_t onceToken;
+    static CFMutableDictionaryRef gLayoutCache;
+    dispatch_once(&onceToken, ^{
+        // If the classification cache doesn't exist, create it.
+        gLayoutCache = CFDictionaryCreateMutable(NULL, 0, NULL, &kCFTypeDictionaryValueCallBacks);
+    });
+    return gLayoutCache;
+}
 
 
 // This class detects releases sent to it and makes that information available to
@@ -170,10 +187,17 @@ static BOOL IsBlock(void *obj)
 {
     // Fetch the selector for the ARC destructor.
     SEL destructorSEL = sel_getUid(".cxx_destruct");
+
+  // `@selector(doNotImplementThisItDoesNotExistReally)` doesn't exist, obviously. Let clang know we
+  // don't care so we don't get a warning.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wundeclared-selector"
 
     // Fetch the IMP for the destructor. Also fetch the IMP for a known unimplemented selector.
     void (*Destruct)(void *, SEL) = (__typeof__(Destruct))class_getMethodImplementation(c, destructorSEL);
     void (*Forward)(void *, SEL) = (__typeof__(Forward))class_getMethodImplementation([NSObject class], @selector(doNotImplementThisItDoesNotExistReally));
+
+#pragma clang diagnostic pop
 
     // If the ARC destructor is not implemented (IMP equals that of an unimplemented selector)
     // then the class contains no strong references. We can just bail out now.
@@ -202,13 +226,12 @@ static BOOL IsBlock(void *obj)
 // Fetch the strong ivar layout for a class, pulling from the cache when possible.
 static NSIndexSet *GetClassStrongLayout(Class c)
 {
-    // If the layout cache doesn't exist, create it now. We'll be adding an entry.
-    if(!gLayoutCache)
-        gLayoutCache = CFDictionaryCreateMutable(NULL, 0, NULL, &kCFTypeDictionaryValueCallBacks);
-
+
+    CFMutableDictionaryRef gLayoutCache = getLayoutCache();
+
     // Fetch the layout from the cache.
     NSIndexSet *layout = (__bridge NSIndexSet *)CFDictionaryGetValue(gLayoutCache, (__bridge void *)c);
-    
+
     // If the layout doesn't exist in the cache, then compute it and cache it.
     if(!layout)
     {
@@ -238,15 +261,13 @@ static BOOL IsBlock(void *obj)
 
     void (*dispose_helper)(void *src) = descriptor->rest[1];
 
-    // If the layout cache doesn't exist, create it now. We'll add an entry to it.
-    if(!gLayoutCache)
-        gLayoutCache = CFDictionaryCreateMutable(NULL, 0, NULL, NULL);
-
+  CFMutableDictionaryRef gLayoutCache = getLayoutCache();
+
     // See if the layout already exists. We can't use the block isa as a key, since different
     // blocks can share an isa. Instead, we use the address of the destructor function as the
     // key, since that destructor will always result in the same layout.
     NSIndexSet *layout = (__bridge NSIndexSet *)CFDictionaryGetValue(gLayoutCache, dispose_helper);
-    
+
     // If the layout doesn't exist in the cache, calculate it using this block's isa, the block's
     // size as pulled from its descriptor, and a destructor that just calls the block destructor.
     if(!layout)
@@ -263,9 +284,7 @@ static BOOL IsBlock(void *obj)
 // Classify an object into one of the listed classifications.
 static enum Classification Classify(void *obj)
 {
-    // If the classification cache doesn't exist, create it.
-    if(!gClassificationCache)
-        gClassificationCache = CFDictionaryCreateMutable(NULL, 0, NULL, NULL);
+    CFMutableDictionaryRef gClassificationCache = getClassificationCache();
 
     // Key classifications off the object's class.
     void *key = (__bridge void *)object_getClass((__bridge id)obj);

CircleTests/CircleTests.h

@@ -6,8 +6,8 @@
 //  Copyright (c) 2012 Michael Ash. All rights reserved.
 //
 
-#import <SenTestingKit/SenTestingKit.h>
+#import <XCTest/XCTest.h>
 
-@interface CircleTests : SenTestCase
+@interface CircleTests : XCTestCase
 
 @end

CircleTests/CircleTests.m

@@ -48,10 +48,10 @@ - (void)testSimpleCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)testSingleObjectCycle
@@ -68,10 +68,10 @@ - (void)testSingleObjectCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)testBlockCycle
@@ -89,10 +89,10 @@ - (void)testBlockCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)testComplexCycle
@@ -118,10 +118,10 @@ - (void)testComplexCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)testReachableCycle
@@ -142,10 +142,10 @@ - (void)testReachableCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNotNil(weakObj, @"Collector collected a referenced cycle");
+    XCTAssertNotNil(weakObj, @"Collector collected a referenced cycle");
 }
 
 - (void)testNSObject
@@ -190,7 +190,7 @@ - (void)testManyCollections
 
     @autoreleasepool {
         for(int i = 0; i < COUNT; i++)
-            STAssertNotNil(weakObjs[i], @"Weak pointer to cycle should not be nil before running the collector");
+            XCTAssertNotNil(weakObjs[i], @"Weak pointer to cycle should not be nil before running the collector");
     }
 
     for(int i = 0; i < COUNT; i++)
@@ -202,7 +202,7 @@ - (void)testManyCollections
     }
 
     for(int i = 0; i < COUNT; i++)
-        STAssertNil(weakObjs[i], @"Collector failed to collect a cycle");
+        XCTAssertNil(weakObjs[i], @"Collector failed to collect a cycle");
 }
 
 - (void)testArrayCycle
@@ -220,10 +220,10 @@ - (void)testArrayCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)testSetCycle
@@ -241,10 +241,10 @@ - (void)testSetCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)testDictionaryCycle
@@ -262,10 +262,10 @@ - (void)testDictionaryCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 - (void)test__blockReference
@@ -295,10 +295,10 @@ - (void)testSimpleSubclassCycle
     }
 
     @autoreleasepool {
-        STAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
+        XCTAssertNotNil(weakObj, @"Weak pointer to cycle should not be nil before running the collector");
     }
     [collector collect];
-    STAssertNil(weakObj, @"Collector didn't collect a cycle");
+    XCTAssertNil(weakObj, @"Collector didn't collect a cycle");
 }
 
 @end

CircleTests/CircleTests-Info.plist → CircleTests/Info.plist

@@ -3,19 +3,19 @@
 <plist version="1.0">
 <dict>
 	<key>CFBundleDevelopmentRegion</key>
-	<string>en</string>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
 	<key>CFBundleExecutable</key>
-	<string>${EXECUTABLE_NAME}</string>
+	<string>$(EXECUTABLE_NAME)</string>
 	<key>CFBundleIdentifier</key>
-	<string>com.mikeash.${PRODUCT_NAME:rfc1034identifier}</string>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
 	<key>CFBundlePackageType</key>
 	<string>BNDL</string>
 	<key>CFBundleShortVersionString</key>
 	<string>1.0</string>
-	<key>CFBundleSignature</key>
-	<string>????</string>
 	<key>CFBundleVersion</key>
 	<string>1</string>
 </dict>