Drew Paroski
e7b90fa691
A recent diff called my attention to the logic in enterDebuggerDummyEnv() and exitDebuggerDummyEnv() and I noticed it didn't look quite right. The first time enterDebuggerDummyEnv() is called it creates a frame on an empty call stack, but then exitDebuggerDummyEnv() does not correctly tear down this frame and null out m_fp and m_pc, and this leads to subtle issues. For example, invokeFunc() checks if m_fp is null to decide whether to call enterVM() or reenterVM(). I found a case with the "flow_gen_excep.php" test where invokeFunc was incorrectly calling reenterVM (because m_fp hadn't been nulled out) and it was pushing bogus VM state info into m_nestedVMs. This in turn was causing the logic in CmdNext::onBeginInterrupt() to get confused when comparing the original stack depth with the current stack depth. This diff updates exitDebuggerDummyEnv() to correctly tear down the frame and null out m_fp and m_pc, and it updates enterDebuggerDummyEnv() to assume the callstack is always empty (which should be the case). I've also beefed up the asserts in both of these methods.
HipHop VM for PHP 
HipHop VM (HHVM) is a new open-source virtual machine designed for executing programs written in PHP. HHVM uses a just-in-time compilation approach to achieve superior performance while maintaining the flexibility that PHP developers are accustomed to. HipHop VM (and before it HPHPc) has realized > 5x increase in throughput for Facebook compared with Zend PHP 5.2.
HipHop is most commonly run as a standalone server, replacing both Apache and modphp.
Installing
You can install a prebuilt package or compile from source.
Running
You can run standalone programs just by passing them to hhvm: hhvm my_script.php.
HipHop bundles in a webserver. So if you want to run on port 80 in the current directory:
sudo hhvm -m server
For anything more complicated, you'll want to make a config.hdf and run sudo hhvm -m server -c config.hdf.
Contributing
We'd love to have your help in making HipHop better. If you run into problems, please open an issue, or better yet, fork us and send a pull request. Join us on #hhvm on freenode.
If you want to help but don't know where to start, try fixing some of the Zend tests that don't pass. You can run them with hphp/test/run. When they work, move them to zend/good and send a pull request.
Before changes can be accepted a Contributors Licensing Agreement (pdf - print, sign, scan, link) must be signed.
Licence
HipHop VM is licensed under the PHP and Zend licenses except as otherwise noted.