Dataflow: Add language specific predicates.

Author: aschackmull

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowPrivate.qll

@@ -3,6 +3,12 @@ private import DataFlowUtil
 private import DataFlowDispatch
 private import FlowVar
 
+/** Gets the callable in which this node occurs. */
+DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
+
+/** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+
 /** Gets the instance argument of a non-static call. */
 private Node getInstanceArgument(Call call) {
   result.asExpr() = call.getQualifier()

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -3,6 +3,12 @@ private import DataFlowUtil
 private import semmle.code.cpp.ir.IR
 private import DataFlowDispatch
 
+/** Gets the callable in which this node occurs. */
+DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
+
+/** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+
 /**
  * A data flow node that occurs as the argument of a call and is passed as-is
  * to the callable. Instance arguments (`this` pointer) and read side effects

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -18,6 +18,12 @@ private import semmle.code.csharp.frameworks.NHibernate
 private import semmle.code.csharp.frameworks.system.Collections
 private import semmle.code.csharp.frameworks.system.threading.Tasks
 
+/** Gets the callable in which this node occurs. */
+DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
+
+/** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+
 abstract class NodeImpl extends Node {
   /** Do not call: use `getEnclosingCallable()` instead. */
   abstract DataFlowCallable getEnclosingCallableImpl();

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPrivate.qll

@@ -3,6 +3,12 @@ private import DataFlowPublic
 import semmle.python.SpecialMethods
 private import semmle.python.essa.SsaCompute
 
+/** Gets the callable in which this node occurs. */
+DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
+
+/** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+
 //--------
 // Data flow graph
 //--------

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll

@@ -6,6 +6,12 @@ private import DataFlowDispatch
 private import SsaImpl as SsaImpl
 private import FlowSummaryImpl as FlowSummaryImpl
 
+/** Gets the callable in which this node occurs. */
+DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
+
+/** Holds if `p` is a `ParameterNode` of `c` with position `pos`. */
+predicate isParameterNode(ParameterNode p, DataFlowCallable c, int pos) { p.isParameterOf(c, pos) }
+
 abstract class NodeImpl extends Node {
   /** Do not call: use `getEnclosingCallable()` instead. */
   abstract CfgScope getCfgScope();