Nat!'s Web Journal

Well lemme check:

-rw-r--r-- 1 nat 100 6140 31 Dec 1999 /Volumes/Source/srcM/PPCReassembly/PPCReassembler/OS.subproj/MachO.subproj/MachOTransformer.m

why, it's right there.

I can't remember having so many problems with XCode 1.1. Maybe I need to reinstall. Apple's installer... hate.... loathe.

I had hoped that developing on my G5 with XCode would be fun, but truth be told I prefer a more reliable workhorse like Visual Studio. VS is not really doing anything fancy, it just has a real nice editor, a very fast compiler and a debugger that just works. The very few bugs and inefficiencies of VS do not prevent me from getting the majority of my work done quickly, which happens to be edit, compile and debug.

XCode on the other hand, neither edits, compiles nor debugs well. The user interface is obscure and clumsy. Make still runs in circles around XCode when compiling. The debugging is broken. - Eclipse on Mac OS X (not on windows) is no real winner either.

Here's a quote off an article from "MacDevCenter" Ten Things I Dig About Xcode:

Der letzte Blick eines Mullopfers.
Der blutdürstige Räuber im Anflug.

In Spiegel Online hat der auf einer journalistischen Stufe mit Bela Rethy stehende Frank Patalong, mal wieder eine seiner Schülerzeitungsartikel eingestellt. Während man den Text, wie üblich, völlig vergessen kann, enthält ein kleiner Kasten ein paar aktuelle und interessante Links.

Ich gehe mal stark davon aus, daß dieser von Spiegel Online angezettelte Minihype schnell wieder abstirbt. :P

Aden:/Volumes/Source/src/Ruby/rubycocoa-0.4.0 nat$ ruby install.rb setup
/Volumes/Source/src/Ruby/rubycocoa-0.4.0/metaconfig:7: warning: don't put space before argument parentheses
/Volumes/Source/src/Ruby/rubycocoa-0.4.0/metaconfig:9: warning: don't put space before argument parentheses
install.rb: entering setup phase...
---> framework
pbxbuild
setup failed
'system pbxbuild' failed
try 'ruby install.rb --help' for usage

CompileC /Library/Developer/BuildArea/RubyCocoa.build/RubyCocoa.build/Objects-normal/ppc/rb_NSGraphicsContext.o
/usr/bin/gcc-3.3 -c -F/Volumes/Source/src/Ruby/rubycocoa-0.4.0/framework/build -I/Volumes/Source/src/Ruby/rubycocoa-0.4.0/framework/build/include -I/usr/local/lib/ruby/1.8/powerpc-darwin -Isrc/objc/cocoa -arch ppc -fno-common -fpascal-strings -Os -Wmost -Wno-four-char-constants -Wno-unknown-pragmas -pipe "-fmessage-length=0" -g -Wp,-header-mapfile,/Library/Developer/BuildArea/RubyCocoa.build/RubyCocoa.build/RubyCocoa.hmap "-fno-common" src/objc/cocoa/rb_NSGraphicsContext.m -o /Library/Developer/BuildArea/RubyCocoa.build/RubyCocoa.build/Objects-normal/ppc/rb_NSGraphicsContext.o
src/objc/cocoa/rb_NSGraphics.m: In function `init_NSGraphics': src/objc/cocoa/rb_NSGraphics.m:1483: error: `NSAlphaEqualToData' undeclared (first use in this function)
src/objc/cocoa/rb_NSGraphics.m:1483: error: (Each undeclared identifier is reported only once
src/objc/cocoa/rb_NSGraphics.m:1483: error: for each function it appears in.)
src/objc/cocoa/rb_NSGraphics.m:1484: error: `NSAlphaAlwaysOne' undeclared (first use in this function)
/System/Library/Frameworks/AppKit.framework/Headers/NSEvent.h: At top level:
src/objc/cocoa/rb_NSGraphics.m:8: warning: `VA_MAX' defined but not used
...failed CompileC /Library/Developer/BuildArea/RubyCocoa.build/RubyCocoa.build/Objects-normal/ppc/rb_NSGraphics.o ...
** BUILD FAILED **
setup failed

Chances are just too good that more problems will appear around the corner.

This function in ImageAndTextCell.m is wrong:

- copyWithZone:(NSZone *)zone {
    ImageAndTextCell *cell = (ImageAndTextCell *)[super copyWithZone:zone];
    cell->image = [image retain];
    return cell;
}

Hint 1: This is also defined in ImageAndTextCell a subclass of NSTextFieldCell:

- (void)setImage:(NSImage *)anImage {
    if (anImage != image) {
        [image release];
        image = [anImage retain];
    }
}

- (NSImage *)image {
    return image;
}

Hint 3: The superclass calls setImage: during copyWithZone:

Hint 4: NSCopyObjectdoes a memcpy of the source object into the copy.

The solution

@interface ImageAndTextCell : NSTextFieldCell {
@private
    NSImage	*image;
}

Notice the clever use of @private there.

NSTextFieldCell subclasses eventually from NSCell. NSCell implements setImage: but has it's own instance variable _support which it uses for setImage: (amongst others).

Now NSCopyObject, which is apparently used, copies both instance variables over to the new cell. When -[NSCell copyWithZone:] calls setImage: to copy over the information (yet again) it calls -[ImageAndTextCell setImage:] with an argument of nil because _support isn't set. This will now release our image and of course that is no good.