C#: Re-factor LambdaDataFlow to use the new API.

Author: michaelnebel

csharp/ql/src/Language Abuse/ForeachCapture.ql

@@ -37,19 +37,19 @@ predicate inForeachStmtBody(ForeachStmt loop, Element e) {
   )
 }
 
-class LambdaDataFlowConfiguration extends DataFlow::Configuration {
-  LambdaDataFlowConfiguration() { this = "LambdaDataFlowConfiguration" }
+module LambdaDataFlowConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { lambdaCapturesLoopVariable(source.asExpr(), _, _) }
 
-  override predicate isSource(DataFlow::Node source) {
-    lambdaCapturesLoopVariable(source.asExpr(), _, _)
-  }
+  predicate isSink(DataFlow::Node sink) { exists(getAssignmentTarget(sink.asExpr())) }
+}
 
-  override predicate isSink(DataFlow::Node sink) { exists(getAssignmentTarget(sink.asExpr())) }
+module LambdaDataFlow {
+  private import DataFlow::Global<LambdaDataFlowConfig>
 
   predicate capturesLoopVarAndIsStoredIn(
     AnonymousFunctionExpr lambda, Variable loopVar, Element storage
   ) {
-    exists(DataFlow::Node sink | this.hasFlow(DataFlow::exprNode(lambda), sink) |
+    exists(DataFlow::Node sink | flow(DataFlow::exprNode(lambda), sink) |
       storage = getAssignmentTarget(sink.asExpr())
     ) and
     exists(ForeachStmt loop | lambdaCapturesLoopVariable(lambda, loop, loopVar) |
@@ -109,7 +109,7 @@ predicate declaredInsideLoop(ForeachStmt loop, LocalVariable v) {
   )
 }
 
-from LambdaDataFlowConfiguration c, AnonymousFunctionExpr lambda, Variable loopVar, Element storage
-where c.capturesLoopVarAndIsStoredIn(lambda, loopVar, storage)
+from AnonymousFunctionExpr lambda, Variable loopVar, Element storage
+where LambdaDataFlow::capturesLoopVarAndIsStoredIn(lambda, loopVar, storage)
 select lambda, "Function which may be stored in $@ captures variable $@.", storage,
   storage.toString(), loopVar, loopVar.getName()