The other callables return control flow nodes,
so it is slightly inconsistent for this to return a
data flow node, but it does make models based
on API graphs nicer.
to ensure that the call graph seen by type tracking
does not include summary calls resolved by type tracking.
(I tried inserting a similar test into the Ruby codebase,
and it still compiled)
To get this to compile, I had to move the resolution of summary calls
out of the data flow nodes and into the `viableCallable` predicate.
This means that we now have a potential summary call for each
cfg call node. (I tried using the base class, `DataFlowCall`, for this
but calls to `map` got identified as class calls and would no longer
be associated with a summary.)
It is possible that the "NonLIbrary"-layers the were inserted into the
hierarchy can be removed again.
- still identifying summarized callables by name.
I think ther shoudl perhaps be a `getAUse` next to `getACall`.
- also fix tests, adding a standard taint configuration
Two classes have been inserted into the hierarchies:
- `NonLibraryDataFlowCallable` with a method `getACall2`.
This method implements "get a call, not considering flow summaries".
For `NonLibraryDataFlowCallable`s, `getACall` will defer to `getACall2`.
While you could have a synthesised call to such a callable,
it would not correspond to a `CallNode`.
- `NonLibraryDataFlowSourceCall` with methods
`getArg2` and `getCallable2`. These also refer to a call graph that
does not consider flow summaries.
`getArg2` is used to synthesise pre-update nodes for arguments.
`getCallable2` is used in `connects` to compute argument passing.
This is used to define data flow nodes for overflow arguments.
`getACall2` ensures that `LibraryCallableValue::getACall` is not called
when the charpred of `FunctionCall` is evaluated.
