Data flow: Add stub expectsContent for all languages

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

@@ -198,6 +198,12 @@ predicate clearsContent(Node n, Content c) {
   none() // stub implementation
 }
 
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
 /** Gets the type of `n` used for type pruning. */
 Type getNodeType(Node n) {
   suppressUnusedNode(n) and

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

@@ -279,6 +279,12 @@ predicate clearsContent(Node n, Content c) {
   none() // stub implementation
 }
 
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
 /** Gets the type of `n` used for type pruning. */
 IRType getNodeType(Node n) {
   suppressUnusedNode(n) and

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

@@ -1714,6 +1714,12 @@ predicate clearsContent(Node n, Content c) {
   )
 }
 
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
 /**
  * Holds if the node `n` is unreachable when the call context is `call`.
  */

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

@@ -160,6 +160,12 @@ predicate clearsContent(Node n, Content c) {
   FlowSummaryImpl::Private::Steps::summaryClearsContent(n, c)
 }
 
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
 /**
  * Gets a representative (boxed) type for `t` for the purpose of pruning
  * possible flow. A single type is used for all numeric types to account for

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

@@ -813,6 +813,12 @@ predicate clearsContent(Node n, Content c) {
   attributeClearStep(n, c)
 }
 
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
 /**
  * Holds if values stored inside attribute `c` are cleared at node `n`.
  *

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

@@ -800,6 +800,12 @@ predicate clearsContent(Node n, ContentSet c) {
   FlowSummaryImpl::Private::Steps::summaryClearsContent(n, c)
 }
 
+/**
+ * Holds if the value that is being tracked is expected to be stored inside content `c`
+ * at node `n`.
+ */
+predicate expectsContent(Node n, ContentSet c) { none() }
+
 private newtype TDataFlowType =
   TTodoDataFlowType() or
   TTodoDataFlowType2() // Add a dummy value to prevent bad functionality-induced joins arising from a type of size 1.