PHPStan is currently in development. First stable version together with documentation will be released in Q1 2016.

Once it's released, it will perform the following checks on your codebase:

• Existence of classes used in instanceof, catch, typehints and other language constructs. PHP does not do this and just stays silent instead.
• Existence and visibility of called methods and functions.
• Existence and visibility of accessed properties.
• Correct number and types of parameters passed to constructors, methods and functions.
• Correct number of parameters passed to sprintf/printf calls based on format strings.
• Existence of variables while respecting scopes of branches and loops.
• Lossless type casts