/** Definitions related to `java.lang.ThreadLocal`. */

overlay[local?]

module;

import java

private import semmle.code.java.dataflow.DataFlow

private import semmle.code.java.dataflow.FlowSteps

/**

* Holds if `cie` construct a `ThreadLocal` object with an overridden

* `initialValue` method with a return value of `init`, such that `init` is the

* initial value of the `ThreadLocal` object.

*/

private predicate threadLocalInitialValue(ClassInstanceExpr cie, Method initialValue, Expr init) {

exists(RefType t, ReturnStmt ret |

cie.getConstructedType().getSourceDeclaration() = t and

t.getASourceSupertype+().hasQualifiedName("java.lang", "ThreadLocal") and

ret.getExpr() = init and

ret.getEnclosingCallable() = initialValue and

initialValue.hasName("initialValue") and

initialValue.getDeclaringType() = t

)

}

private class ThreadLocalInitialValueStore extends AdditionalStoreStep {

override predicate step(DataFlow::Node node1, DataFlow::Content c, DataFlow::Node node2) {

exists(Method initialValue, Expr init |

threadLocalInitialValue(_, initialValue, init) and

node1.asExpr() = init and

node2.(DataFlow::InstanceParameterNode).getCallable() = initialValue and

c.(DataFlow::SyntheticFieldContent).getField() = "java.lang.ThreadLocal.value"

)

}

}

private class ThreadLocalInitialValueStep extends AdditionalValueStep {

override predicate step(DataFlow::Node node1, DataFlow::Node node2) {

exists(ClassInstanceExpr cie, Method initialValue |

threadLocalInitialValue(cie, initialValue, _) and

node1.(DataFlow::InstanceParameterNode).getCallable() = initialValue and

node2.asExpr() = cie

)

}

}