C++: Data flow through & and *#1778
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The data flow library conflates pointers and objects enough for the `definitionByReference` predicate to be too strict in some cases. It was too permissive in other cases that are now (or will be) handled better by field flow. See also the change note entry.
This means that the pre-update node for the `DefinitionByReferenceNode` in `f(&x)` is now `x` rather than `&x`. That has little effect on the test results apart from removing some false flow around `memcpy`.
The data flow library conflates pointers and their objects in some places but not others. It might be ideal to avoid that conflation, but that's not realistic without using the IR. We've had good experience in the taint tracking library with conflating pointers and objects, and it improves results for field flow, so perhaps it's time to try it out for all data flow.
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Superseded by #1884. |
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(the first two commits are from #1777).
The data flow library conflates pointers and their objects in some places but not others. It might be ideal to avoid that conflation, but that's not realistic without using the IR.
We've had good experience in the taint tracking library with conflating pointers and objects, and it improves results for field flow, so perhaps it's time to try it out for all data flow.
To do: performance testing, change note, and discussing whether this is a good idea at all.