Previously, `AllConfigurations.qll` would pull in (almost) all taint
tracking configurations, which has started causing OOMEs during
compilation.
I've pruned it down to only the most interesting configurations. Since
flow summaries are experimental at this point and require a bit of manual
configuration anyway, this shouldn't be much of an issue in practice.
My recent changes to suppress FPs in `ReturnStackAllocatedMemory.ql`
caused us to lose all results where there was a `Conversion` at the
initial address escape. We cannot handle conversions in general, but
this commit restores the good results for the trivial types of
conversion that we can handle.
The main source of slowness in `BrokenCryptoAlgorithm.ql` was that the
regexp on function (macro) names was evaluated once per call
(invocation) instead of once per name. Factoring out separate predicates
for the problematic functions (macros) fixes this.
On https://github.com/ericniebler/range-v3, this change reduces the run
time of the two slowest predicates from
BrokenCryptoAlgorithm::InsecureMacroSpec#class#f .... 35.1s
BrokenCryptoAlgorithm::InsecureFunctionCall#class#f . 12.8s
to
BrokenCryptoAlgorithm::getAnInsecureFunction#f . 1.2s
BrokenCryptoAlgorithm::getAnInsecureMacro#f .... 12ms
Instead of `algorithmBlacklistRegex` having 2 * 5 results, it now has
only one result, which is a single regex that represents the union of
the previous 2 * 5 regexes. This means that `BrokenCryptoAlgorithm.ql`
has much less regex matching to do.
On https://github.com/ericniebler/range-v3, this change reduces the run
time of the two slowest predicates from
BrokenCryptoAlgorithm::InsecureMacroSpec#class#f .... 2m21s
BrokenCryptoAlgorithm::InsecureFunctionCall#class#f . 54.5s
to
BrokenCryptoAlgorithm::InsecureMacroSpec#class#f .... 35.1s
BrokenCryptoAlgorithm::InsecureFunctionCall#class#f . 12.8s
Since we cannot track data flow from a fully-converted expression but
only the unconverted expression, we should check whether the address
initially escapes into the unconverted expression, not the
fully-converted one.
This fixes most of the false positives observed on lgtm.com.
