Merge pull request github#13070 from michaelnebel/csharp/refactorfollowup

C#: Re-factor CIL data flow test to use the new API.

Author: michaelnebel

csharp/ql/src/experimental/Security Features/CWE-759/HashWithoutSalt.ql

@@ -10,8 +10,6 @@
  */
 
 import csharp
-import semmle.code.csharp.dataflow.DataFlow2
-import semmle.code.csharp.dataflow.TaintTracking2
 import HashWithoutSalt::PathGraph
 
 /** The C# class `Windows.Security.Cryptography.Core.HashAlgorithmProvider`. */
@@ -77,7 +75,7 @@ predicate isHashCall(MethodCall mc) {
 
 /** Holds if there is another hashing method call. */
 predicate hasAnotherHashCall(MethodCall mc) {
-  exists(MethodCall mc2, DataFlow2::Node src, DataFlow2::Node sink |
+  exists(MethodCall mc2, DataFlow::Node src, DataFlow::Node sink |
     isHashCall(mc2) and
     mc2 != mc and
     (

csharp/ql/test/library-tests/cil/dataflow/DataFlow.ql

@@ -3,45 +3,47 @@
  */
 
 import csharp
-import DataFlow
+import Flow::PathGraph
 
-private predicate relevantPathNode(PathNode n) {
+private predicate relevantPathNode(Flow::PathNode n) {
   exists(File f | f = n.getNode().getLocation().getFile() |
     f.fromSource()
     or
     f.getBaseName() = "DataFlow.dll"
   )
 }
 
-query predicate edges(PathNode a, PathNode b) {
-  PathGraph::edges(a, b) and
+query predicate edges(Flow::PathNode a, Flow::PathNode b) {
+  Flow::PathGraph::edges(a, b) and
   relevantPathNode(a) and
   relevantPathNode(b)
 }
 
-query predicate nodes(PathNode n, string key, string val) {
-  PathGraph::nodes(n, key, val) and
+query predicate nodes(Flow::PathNode n, string key, string val) {
+  Flow::PathGraph::nodes(n, key, val) and
   relevantPathNode(n)
 }
 
-query predicate subpaths(PathNode arg, PathNode par, PathNode ret, PathNode out) {
-  PathGraph::subpaths(arg, par, ret, out) and
+query predicate subpaths(
+  Flow::PathNode arg, Flow::PathNode par, Flow::PathNode ret, Flow::PathNode out
+) {
+  Flow::PathGraph::subpaths(arg, par, ret, out) and
   relevantPathNode(arg) and
   relevantPathNode(par) and
   relevantPathNode(ret) and
   relevantPathNode(out)
 }
 
-class FlowConfig extends Configuration {
-  FlowConfig() { this = "FlowConfig" }
+module FlowConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source.asExpr() instanceof Literal }
 
-  override predicate isSource(Node source) { source.asExpr() instanceof Literal }
-
-  override predicate isSink(Node sink) {
+  predicate isSink(DataFlow::Node sink) {
     exists(LocalVariable decl | sink.asExpr() = decl.getInitializer())
   }
 }
 
-from PathNode source, PathNode sink, FlowConfig config
-where config.hasFlowPath(source, sink)
+module Flow = DataFlow::Global<FlowConfig>;
+
+from Flow::PathNode source, Flow::PathNode sink
+where Flow::flowPath(source, sink)
 select source, sink, sink, "$@", sink, sink.toString()