Try to make code more robust and comment copiously.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@32107 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,8 +1,8 @@
 2011-02-12  Richard Frith-Macdonald <rfm@gnu.org>
 
-	* Source/NSZombie.m: Get zombie class to set up class pointer in
-	+initialize rather than using +class since +class is not implemented
-	and David says support for it is runtime specific.
+	* Source/NSObject.m: Obtain NSZombie class pointer using
+	objc_lookUpClass() to avoid the use of NSString inside the NSObject
+	initialize method. Re-order code for safety. Add lots of comments.
 
 2011-02-12  Richard Frith-Macdonald <rfm@gnu.org>
 
@@ -487,14 +487,16 @@
 2010-12-31 Stefan Bidigaray <stefanbidi@gmail.com>
 
 	* Headers/Foundation/NSCalendar.h:
-	* Source/NSCalendar.m: Added iOS 4.0 and later methods to NSDateComponents.
+	* Source/NSCalendar.m: Added iOS 4.0 and later methods
+	to NSDateComponents.
 
 2010-12-31 Stefan Bidigaray <stefanbidi@gmail.com>
 
 	* Resources/GNUmakefile:
 	* Resources/Languages/Locale.canonical: Added mapping to go from long
 	locale identifiers to the shorter identifiers used by ICU.
-	* Source/NSLocale.m: Implemented -canonical* and -preferredLanaguges methods.
+	* Source/NSLocale.m: Implemented -canonical* and -preferredLanaguges
+	methods.
 
 2010-12-31 14:03  David Chisnall <theraven@gna.org>
 

Source/NSObject.m

@@ -105,7 +105,6 @@ static Class	NSConstantStringClass;
 {
   Class	isa;
 }
-+ (void) initialize;
 - (Class) class;
 - (void) forwardInvocation: (NSInvocation*)anInvocation;
 - (NSMethodSignature*) methodSignatureForSelector: (SEL)aSelector;
@@ -948,31 +947,58 @@ objc_create_block_classes_as_subclasses_of(Class super) __attribute__((weak));
 #  endif
 #endif
 
+
 #ifdef HAVE_LOCALE_H
-      GSSetLocaleC(LC_ALL, "");		// Set up locale from environment.
+      /* Set up locale from environment.
+       * This function should not use any ObjC code since important
+       * classes are not yet initialized.
+       */
+      GSSetLocaleC(LC_ALL, "");
 #endif
 
-      // Create the global lock
+      /* Create the global lock.
+       * NB. Ths is one of the first things we do ... setting up a new lock
+       * must not call any other Objective-C classes and must not involve
+       * any use of the autorelease system.
+       */
       gnustep_global_lock = [NSRecursiveLock new];
 
-      // Behavior debugging
+      /* Behavior debugging ... enable with environment variable if needed.
+       */
       GSObjCBehaviorDebug(GSPrivateEnvironmentFlag("GNUSTEP_BEHAVIOR_DEBUG",
 	GSObjCBehaviorDebug(-1)));
 
-      // Zombie management flags.
-      NSZombieEnabled = GSPrivateEnvironmentFlag("NSZombieEnabled", NO);
-      NSDeallocateZombies = GSPrivateEnvironmentFlag("NSDeallocateZombies", NO);
-      [NSZombie initialize];
-
-      // Set up the autorelease system
+      /* Set up the autorelease system ... we must do this before using any
+       * other class whose +initialize might autorelease something.
+       */
       autorelease_class = [NSAutoreleasePool class];
       autorelease_sel = @selector(addObject:);
       autorelease_imp = [autorelease_class methodForSelector: autorelease_sel];
 
-      // Make sure the constant string class works.
+      /* Make sure the constant string class works and set up well-known
+       * string constants etc.
+       */
       NSConstantStringClass = [NSString constantStringClass];
       GSPrivateBuildStrings();
 
+      /* Determine zombie management flags and set up a map to store
+       * information about zombie objects.
+       */
+      NSZombieEnabled = GSPrivateEnvironmentFlag("NSZombieEnabled", NO);
+      NSDeallocateZombies = GSPrivateEnvironmentFlag("NSDeallocateZombies", NO);
+      zombieMap = NSCreateMapTable(NSNonOwnedPointerMapKeyCallBacks,
+	NSNonOwnedPointerMapValueCallBacks, 0);
+
+      /* We need to cache the zombie class.
+       * We can't call +class because NSZombie doesn't have that method.
+       * We can't use NSClassFromString() because that would use an NSString
+       * object, and that class hasn't been initialized yet ...
+       */
+      zombieClass = objc_lookUpClass("NSZombie");
+
+      /* Now that we have a workign autorelease system and working string
+       * classes we are able to set up notifications.
+       */
       [[NSNotificationCenter defaultCenter]
 	addObserver: self
 	   selector: @selector(_becomeMultiThreaded:)
@@ -2250,15 +2276,6 @@ objc_create_block_classes_as_subclasses_of(Class super) __attribute__((weak));
 
 
 @implementation	NSZombie
-+ (void) initialize
-{
-  if (nil == zombieClass)
-    {
-      zombieMap = NSCreateMapTable(NSNonOwnedPointerMapKeyCallBacks,
-	NSNonOwnedPointerMapValueCallBacks, 0);
-      zombieClass = [NSZombie class];
-    }
-}
 - (Class) class
 {
   return (Class)isa;