- add `getCallable`, `getArg` and `getNode`
- these are `none` for summary calls
- revert "external" uses (they had been changed to `DataFlowSourceCall`)
This is partly motivated by the MaD tests which looks much better now in
my opinion.
I also wanted this for testing argument passing. In Python we're
adopting the same argument positions as Ruby has
[here](4f3751dfea/ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowDispatch.qll (L508-L540))
So it would be nice if `arg[keyword foo]=...` was allowed, without
having to transform the `toString()` result of an argument position into
something without a space.
- 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.
- Branch predicates are made simple. In particular, they do not try to detect library calls.
- All branches based on `CallNode`s are gathered into one.
- That branch has been given a class `NonSpecialCall`, which is the new parent of call classes based on `CallNode`s. (Those classes now have more involved charpreds.)
- A new such class, 'LambdaCall` has been split out from `FunctionCall` to allow the latter to replace its
general `CallNode` field with a specific `FunctionValue` one.
- `NonSpecialCall` is not an abstract class, but it has some abstract overrides. Therefor, it is not
considered a resolved call in the test `UnresolvedCalls.qll`.
