Software Development

Have you tried Clang yet? Clang is an open-source compiler, under active development, that aims to replace GCC for compiling C, C++, and Objective-C. Compared to GCC, Clang is faster, while generating comparably fast code, and prints more useful error messages.

Clang is also better for developers who want to compile code programmatically. Unlike GCC, Clang is designed to be both a tool and an API. That makes Clang’s source code easier to understand and reuse. And, for those of us working on projects incompatible with GCC’s GPL license, it’s good to know that Clang is distributed under the BSD license.

Kosada is working on a cool new project that’s built on top of Clang and its underlying framework, LLVM. While using Clang for this project, I’ve been pleased to see how simple it is to write code that builds other code. Simple in retrospect, anyway! The code I wrote turned out to be simple, but it took lots of digging through the Clang source code to figure out what to write. So here’s my first contribution to the Clang community: two examples of using the Clang API to build code programmatically.

Firebug is one of those vital extensions for web developers and designers who use Firefox. I have been faithfully updating it whenever it whines at me to update it, which is usually every minor version, and it pretty much just works. Firebug and I have a romance of debugging HTML, CSS, and more recently the Javascript and JQuery that I use in Select Other, Processing, and some more recent custom development for Slight High.

The honeymoon ended recently…

The IOSurface framework lets you pass a reference to an IOSurface — a kind of pixel buffer — from one process to another. Here’s an example of how to pass an IOSurface through a mach port using the functions IOSurfaceCreateMachPort and IOSurfaceLookupFromMachPort.

Mach ports are a way for processes to communicate in Mac OS X. (Other mechanisms for inter-process communication include distributed objects and sockets.) A mach port is an endpoint of a communication channel. If 2 processes hold endpoints to the same communication channel, then one process can send messages to the other.

Mac OS X provides wrappers around mach ports — NSMachPort and CFMachPort. But sometimes you have to drop down to the native mach_port_t API.

Don’t do this on whim.

• Works on Snow Leopard (with Mail.app running in either 32bit or 64bit).
• After moving a message, automatically selects the following message (instead of selecting nothing).

Mailbundle attached.

Steve Mokris is a developer at Kosada, Inc.

There are a few functions used to zero out memory on most unix variants. memset(), bzero(), and calloc() are all a few such functions. calloc() isn’t very useful for clearing already allocated memory, so it won’t be appearing much more in this article. However, the other two are somewhat more interesting than meets the eye.