Bison/YACC generated files result in a very large number of (presumably) false positives from the analyzer.
These false positives are "true" in a sense of the information analyzer sees: assuming that the lexer can return any token at any point a number of uninitialized reads does occur.
(naturally, the analyzer can not capture a complex invariant that certain tokens can only occur under certain conditions).
Current fix simply stops analysis on those files.
I have examined a very large number of such auto-generated files, and they do all start with such a comment.
Conversely, user code is very unlikely to contain such a comment.
rdar://33608161
Could we use Buffer->getBuffer().startswith(...) instead?