To speed up the taint analysis in `NonConstantFormat.ql` and to remove
FPs that were due to taint spreading from `i` to `a[i]`, this commit
stops the taint tracking in `NonConstantFormat.ql` at every node that
could not possibly contain a string.
I tested performance on Wireshark, and it's fine. Pulling out the
`isSanitizerNode` prevented `isSanitizer` from turning into four
half-slow RA predicates due to both CPE and `#antijoin_rhs`
transformations happening.
This query is supposed to look for constructors that unintentionally qualify as copy constructors due to default arguments. There are quite a few real-world projects that define such constructors intentionally. I've reduced the severity to "warning" and the precision to "low" due to the high false positive rate.
Querying for overlap type wasn't possible when this library was first
written. This change fixes FPs in `RedundantNullCheckSimple.ql` on
Wireshark and other real-world projects.
IR construction was missing support for C++ 11 range-based `for` loops. The extractor generates ASTs for the compiler-generated implementation already, so I had enough information to generate IR. I've expanded on some of the predicates in `RangeBasedForStmt` to access the desugared information.
One complication was that the `DeclStmt`s for the compiler-generated variables seem to have results for `getDeclaration()` but not for `getDeclarationEntry()`. This required handling these slightly differently than we do for other `DeclStmt`s.
The flow for range-based `for` is actually easier than for a regular `for`, because all three components (init, condition, and update) are always present.
It turns out we didn't have to move the `getName` implementation into
the mirror classes in `QualifiedName`. Doing so only made it harder for
the optimiser to specialize calls to `getName` on various kinds of
`Declaration`.
