LLVM projects you may not be aware of

All Mac and iPhone OS developers must by now be familiar with LLVM, the Low-Level Virtual Machine compiler that Apple has backed in preference to GCC (presumably at least partially because because GCC 4.5 is now a GPLv3 project, in addition to technical problems with improving the older compiler). You'll also be familiar with Clang, the modular C/ObjC/C++ lexer/parser that can be used as an LLVM front-end, or as a library for providing static analysis, refactoring and other code comprehension facilities. And of course MacRuby uses LLVM's optimisation libraries.

The LLVM umbrella also covers a number of other projects that Mac/iPhone developers may not yet have heard about, but which nonetheless are pretty cool. This post is just a little tour of some of those. There are other projects that have made use of LLVM code, but which aren't part of the compiler project - they are not the subject of this post.

LibC++ is a C++ library, targeting 100% compatibility with the C++0x (draft) standard.

KLEE looks very cool. It's a "symbolic execution tool", capable of automatically generating unit tests for software with high degrees of coverage (well over 90%). Additionally, given information about an application's constraints and requirements it can automatically discover bugs, generating failing tests to demonstrate the bug and become part of the test suite. There's a paper describing KLEE including a walkthrough of discovering a bug in tr, and tutorials in its use.

vmkit is a substrate layer for running bytecode. It takes high-level bytecode (currently JVM bytecode or IL, the bytecode of the .Net runtime) and translates it to IR, the LLVM intermediate representation. In doing so it can make use of LLVM's optimisations and make better decisions regarding garbage collection.

How to hire Graham Lee

There are few people who can say that when it comes to Cocoa application security, they wrote the book. In fact, I can think of only one: me. I've just put the final draft together for Professional Cocoa Application Security and it will hit the shops in June: click the link to purchase through my Amazon affiliate programme.

Now that the book's more-or-less complete, I can turn my attention to other interesting projects: by which I mean yours! If your application could benefit from a developer with plenty of security experience and knowledge to share in a pragmatic fashion, or a software engineer who led development of a complex Cocoa application from its legacy PowerPlant origins through Snow Leopard readiness, or a programmer who has worked on performance enhancement in networking systems and low-level daemon code on Darwin and other UNIX platforms, then your project will benefit from an infusion of the Graham Lee magic. Even if you have some NeXTSTEP or OPENSTEP code that needs maintaining, I can help you out: I've been using Cocoa for about as long as Apple has.

Send an email to iamleeg <at> securemacprogramming <dot> com and let's talk about your project. The good news is that for the moment I am available, you probably can afford me[*], and I really want to help make your product better. Want to find out more about my expertise? Check out my section on the MDN show, and the MDN security column.

[*] It came up at NSConference that a number of devs thought I carry a premium due to the conference appearances, podcasts and other material I produce. Because I believe that honesty is the best policy, I want to come out and say that I don't charge any such premium. My rates are consistent with other contractors with my level of experience, and I even provide a discounted rate for NGOs and academic institutions.

I may have not been correct

When I said Apple should buy Sun, whether that was a good idea or not, it seems to have failed to occur. Instead, we find that Oracle have done the necessary. Well, there goes my already-outdated SUNW tag. Presumably they'll keep Java (the licensing revenue is actually pretty good), MySQL (I've heard that Oracle make databases), the OS and a subset of the hardware gear. Then they'll become the all-in-one IT industry in a box vendors that Cisco have yet to organise, with (presumably x86) servers running the Solaris-Glassfish-Oracle-Java app stack in some insanely fast fashion. I wonder how many of the recent leftfield hardware projects they'll just jettison, and who will end up running the Santa Clara business unit...

Solaris iPhone Edition

Apple's one new feature in Snow Leopard is support for Exchange, which if not squarely an Enterprise lure is certainly bait for medium businesses. But here we hit Apple's perennial problem; they want to sell more into businesses (because that's where at least 2/3 of all PC money is to be made) but they want to design their systems for home users. When a system is designed to cover every possible potential use for a computer we end up with Windows, which is the kind of "few things to all people" solution that Apple are - rightly - keen to avoid. But as Tim Cook's "state of the Mac" segment in the recent laptop event showed, one of Apple's biggest growth areas is education which is organised along enterprisey lines.

Their solution thus far has been a partial one; we get Mac OS X which is basically a consumer OS, and then we get Mac OS X server which is the same OS with a few configuration changes and extra apps to support being used as a workgroup server. This is less distinct than the changes between Mac OS X and iPhone OS X, but the principle is the same; the same technology is used in different ways, so we get different interfaces to it. Note that these aren't really very divergent products - a UNIX expert could set up an Open Directory Master on a standard Mac OS X box were they so inclined. We get the Mac Pro and the XServe as nods to the existence of more powerful hardware than the iMac. While Apple do have a network of business development managers, enterprise sales people, sales engineers and so on who can support larger customers, their capabilities and freedom are restricted by working on a consumer product in a consumer organisation.

Assuming that Apple aren't going to retreat and consolidate all of their effort on the consumer/prosumer, the logical plan seems to be "the same only more so"; carry on the scheme of applying a common technology base to multiple markets, but with the product interfaces and configurations being specific to the role in which they'll be used. Empower those enterprise sales, support and development teams to make the changes required in both the shared technology base and the domain-specific parts in order to advance their own cause. Allow them to do so in such a way that the consumer focus of the standard products is not diluted. To do all this, what Apple would need is to clearly delineate their Core OS, Consumer OS and Server OS engineering groups, while adding staff, expertise and intellectual property to their Server OS, Server Hardware and Enterprise Support groups.

The bit about "adding staff, expertise and intellectual property to their Server OS, Server Hardware and Enterprise Support groups" can be easily achieved by using the Blue Peter principle. Here's one I prepared earlier. And no, I'm not going mad. Sun have plenty of experience in supporting larger customers and what marketing people like to call vertical markets, and have some good technology: hardware, operating systems software, enterprise services and applications. Their only problem is that they can't make any money on it. On the other hand with Apple it seems that the money is there to be made, and the problem is stepping up to that plate without compromising the consumer products. Consolidating Mac OS X [+ Server] and Solaris 10 would not be trivial but is not beyond the realms of fantasy. NeXTSTEP ran on SPARC hardware, and as we know that Mac OS X runs on PPC, two different Intel architectures and ARM it's likely that the effort to port Mac OS X to SPARC would not be great. But perhaps more useful in the short term is that OpenStep ran on Solaris before, and could do again. Even though Sun have switched Solaris to a SYSV-derived platform, due to Apple's recent push for standardisation with Leopard the two OS are likely more source-code compatible than NeXTSTEP and SunOS 4 ever were. Getting Cocoa up on Solaris would mean that application portability (for the sorts of apps that server admins will want - including Apple's own server admin tools, not for OmniDazzle) becomes viable while the combined company (Snapple?) concentrate on integrating the core tech. They could even get Jonathan Schwartz to do the coding.

Another factor in this proposition is that JAVA is cheap. Apple currently have about $20B in cash and Sun's shares are worth $3.6B, but taking into account that Sun have lost 98% of their dot-com-boom value without slowing their R&D projects, the value for money when you want them for their tech, smarts and goodwill rather than their user base is astounding.

Oh, and speaking of JAVA, what about Java? Java currently represents Sun's main income due to the licensing scheme, but Apple's investment in the platform has declined over time from the Rhapsody days of "everything is Java"; currently the available Java on Mac OS X lags behind Sun's version and isn't ppc64 compatible. The WebObjects team (and hence the Apple store and iTunes) have a heavy Java investment, while other teams have dropped Java (Cocoa) and still others eschew it completely. The iPhone has a very busy developer ecosystem - and absolutely no Java. Where the hypothetical Snapple would leave Java is entirely open, but the option of packaging up the combined company's Java assets and re-selling them would seem unnecessary, unless you thought that even $3.6B was too much to pay.

Don't go there

From the title linky: " Mobility is only available for Windows and Linux." Good job no-one bases their mobile appliances on Mac OS X ;-)

Why Java is so damned lame, part exp(I*M_PI)

Gah. Back when I used to work for Oxford University, I had to do the occasional bit of Java programming for a WebObjects app. Being quite a bit more familiar with ObjC than with Java, I always found this a bit of a headache...partly the way Java Foundation is semi-bridged with the "real" Java API meant I was constantly referring to my Tiger book (Java in a Nutshell, not Mac OS X Tiger), and partly because ironically Java required a lot more mystical casting voodoo than ObjC...seriously, if I never see the phrase Session session=(Session)session() again, I'll be a happy man.

Today's "gah, why can't Java be as easy as ObjC" moment came courtesy of an algorithmic problem I was attacking at TopCoder, just for the hell of it. Problem is, to get to their problem definitions you have to use their applet thingy, and while I'm there I decided that I may as well type the code into their thingy after all Java's not that bad is it? [They also accept VB, C# and C++ but my recollection of the C++ class syntax is slim and my knowledge of the STL is slimmer...I do know enough to try and avoid it though] So I think their problem definitions are proprietary, but suffice to say I wanted the ability to compare two strings, returning equal if the strings could be made the same by popping any arbitrary number of characters off the front and shifting them onto the back (i.e. treating them like rings of characters).

Well, that's simple isn't it? In ObjC I'd subclass NSString, override isEqual: and Robert is your parent's sibling. I even know how to do that in Java:

class CircularString extends String {
  public boolean equals(Object otherObj) {
    //....
  }
}

Only...no. You're not allowed to do that, because for some unfathomable reason Gosling and the boys at Oak decided to inflict on us another voodoo keyword...final. This seems to have one purpose in existence: to stop me from subclassing the String class. In the words of Points of View, Why oh why oh why oh why?