[Cpp] Mapping dataflow nodes to their basic blocks.

[jackfromeast]

I'm trying to map Dataflow::Node instances to their corresponding BasicBlock in C++.

My initial approach was to convert nodes using node.asExpr().getBasicBlock(), node.asParameter().getBasicBlock(), or node.asDefiningArgument().getBasicBlock(), but many dataflow nodes return none for node.asExpr() (>85%), making this unreliable as I would loss a lot of unmapped nodes.

I then discovered that Dataflow::Node from semmle/code/cpp/ir/IR.qll has a getBasicBlock() predicate returning an IRBlock, which works for most nodes except function parameters. However, I'm now stuck on how to convert an IRBlock to a BasicBlock, as other information is more accessible from the BasicBlock.

Overall, I am wondering is there a better approach to reliably map all dataflow nodes to their corresponding basic blocks?