Hi All, So—I am trying to use swizzling for my first ever and my goal is to swizzle `alloc`. Why? I want to run a unqiued counter of where my objects are allocated by analyzing the call stack symbols. Sort of like Valgrind so that I can see where my program is leaking data—but I figured since I don't know how to parse Valgrind Objective-C might be an easier way to get something very similar.
Unfortunately when I follow this guide to swizzle the methods—I am getting a segmentation fault. https://newrelic.com/blog/best-practices/right-way-to-swizzle He basically tell me to do: > > id gtkDebugAlloc(id self, SEL cmd) { .... } > > { > Method nsObjectAllocMethod = class_getClassMethod([NSObject > class], @selector(alloc)); > IMP orginalAlloc = > method_setImplementation(nsObjectAllocMethod,(IMP)gtkDebugAlloc); > } Instead of: > @interface GTKDebugObject > @end > @implementation GTKDebugObject > +(id)alloc { id toReturn = [self > allocWithZone:NSDefaultMallocZone()]; if (toReturn { ... } return toReturn; } > @end > > { > > Method nsObjectAllocMethod = class_getClassMethod([NSObject > class], @selector(alloc)); > Method gtkObjectAllocMethod = > class_getClassMethod([GTKDebugObject class], @selector(alloc)); > method_exchangeImplementations(nsObjectAllocMethod, > gtkObjectAllocMethod); > > } Both methods immediatley give me a segmentation fault when I run this. Not really sure where to begin debugging this given it's my first time ever swizzling something. Another approaoch would be to have my own build of `Foundation`. I am probably going to do that next—but this would be a much handier tool if I didn't have to rebuild my system everytime I wanted to debug my mistakes. So far, I don't really know how to tell GNUmake to use another version of Foundation. It seems like I can change my Foundation library for cross-compiling but not the location of Foundation lookup. . /usr/GNUstep/System/Library/Makefiles/GNUstep-reset.sh export LIBRARY_COMBO=ng-gnu-gnu . /usr/GNUstep/System/Library/Makefiles/GNUstep.sh Ref: http://manpages.ubuntu.com/manpages/impish/man7/library-combo.7.html Seeing also: http://www.gnustep.org/resources/documentation/make_1.html#SEC33 Would appreciate the help as I go off and bang my head on this. Might have a very easy solution. Thank for any help in advance, G
