KeychainAPI checker: Generate an error on double allocation. Pull out getAsPointeeMemoryRegion so that it could be reused.

llvm-svn: 136952

KeychainAPI checker: Track additional pair of SecKeychain APIs. Also, keep exploring the transition on which a call to allocator function failed (to be able to find errors in examples like ErrorCodesFromDifferentAPISDoNotInterfere).

llvm-svn: 136930

KeychainAPI checker: Refactor to make it easier to add more allocator/deallocator API pairs. Add the allocator function ID to the checker state. Better comments.

llvm-svn: 136889

llvm-svn: 136852

KeychainAPI checker: Add basic diagnostics. Track MemoryRegion istead of SymbolicRef since the address might not be a symbolic value in some cases, for example in fooOnlyFree() test.

llvm-svn: 136851

KeychainAPI checker: only check the paths on which the allocator function returned noErr. (+ minor cleanup)

llvm-svn: 136694

Add a skeleton for the Keychain Services API Checker. Register it as OSX experimental for now. Note, the checker still does not handle tracking of escaped values, taking into account the return value of the allocator functions, nor the actual bug reporting.. 

llvm-svn: 136659