In a new post to his blog Sebastian Bergmann takes a quick look at using a static analyzer, clang and scan-build, to analyze the PHP interpreter (specifically during the compile process).
I have been tinkering with CLANG's static analyzer lately. This post summarizes how I installed LLVM and CLANG and performed the analysis of a build of the PHP interpreter.
He includes all the commands (unix-based) to get the clang tools/libraries installed in the correct places as well as what to add to your $PATH to get the "scan-build" command to work with the make and make install parts of the PHP compile process.