Class FlowVar

A conceptual variable that is assigned only once, like an SSA variable. This class is used for tracking data flow through variables, where the desired semantics is sometimes different from what the SSA library provides. Unlike SSA, there are no phi nodes; instead, each VariableAccess may be associated with more than one FlowVar.

Each instance of this class corresponds to a modification or an initial value of a variable. A FlowVar has exactly one result for either definedByExpr or definedByInitialValue. The documentation on those two member predicates explains how a FlowVar relates to syntactic constructs of the language.

Import path

import semmle.code.cpp.dataflow.internal.FlowVar

Direct supertypes

TFlowVar

Known direct subtypes

Predicates

definedByExpr	Holds if this `FlowVar` corresponds to a modification occurring when `node` is evaluated, receiving a value best described by `e`. The following is an exhaustive list of cases where this may happen.
definedByInitialValue	Holds if this `FlowVar` corresponds to the initial value of `v`. The following is an exhaustive list of cases where this may happen.
definedPartiallyAt	Holds if this `FlowVar` is a `PartialDefinition` whose outer defined expression is `e`. For example, in `f(&x)`, the outer defined expression is `&x`.
getAnAccess	Gets a `VariableAccess` that may take its value from `this`. Consider the following snippet.
getLocation	Gets the location of this element.
reachesRefParameter	Holds if this `FlowVar` is a definition of a reference parameter `p` that persists until the function returns.
toString	Gets a textual representation of this element.