C++: Add a predicate for getting dataflow nodes whose value has been constant folded #13895
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Consider the following program:
if one writes the expected taint-tracking query to identify flow from the constant
1
to an argument ofsink
:then this won't work because
1
has been constant folded during IR construction into the value of the expression1 | C
. Thus, even though taint-tracking allows flow through bitwise OR, this won't have any result.This PR adds a new predicate on
DataFlow::Node
s calledasFoldedConstant
. The expressionnode.asFoldedConstant()
gives all the constants that has been folded into the node's underlyingIntegerConstantInstruction
. This allows one to find flow in the above example by replacingwith