Shared: Move shared logic into FlowSummaryImpl.qll

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

@@ -731,11 +731,9 @@ module LocalFlow {
     or
     node2 = node1.(LocalFunctionCreationNode).getAnAccess(true)
     or
-    node1 =
-      unique(FlowSummaryNode n1 |
-        FlowSummaryImpl::Private::Steps::summaryLocalStep(n1.getSummaryNode(),
-          node2.(FlowSummaryNode).getSummaryNode(), true, _)
-      )
+    FlowSummaryImpl::Private::Steps::summaryLocalMustFlowStep(node1
+          .(FlowSummaryNode)
+          .getSummaryNode(), node2.(FlowSummaryNode).getSummaryNode())
   }
 }
 

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

@@ -160,11 +160,8 @@ predicate localMustFlowStep(Node node1, Node node2) {
   or
   node2.asExpr().(AssignExpr).getSource() = node1.asExpr()
   or
-  node1 =
-    unique(FlowSummaryNode n1 |
-      FlowSummaryImpl::Private::Steps::summaryLocalStep(n1.getSummaryNode(),
-        node2.(FlowSummaryNode).getSummaryNode(), true, _)
-    )
+  FlowSummaryImpl::Private::Steps::summaryLocalMustFlowStep(node1.(FlowSummaryNode).getSummaryNode(),
+    node2.(FlowSummaryNode).getSummaryNode())
 }
 
 import Cached

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

@@ -175,11 +175,9 @@ module LocalFlow {
     or
     node1 = node2.(ImplicitBlockArgumentNode).getParameterNode(true)
     or
-    node1 =
-      unique(FlowSummaryNode n1 |
-        FlowSummaryImpl::Private::Steps::summaryLocalStep(n1.getSummaryNode(),
-          node2.(FlowSummaryNode).getSummaryNode(), true, _)
-      )
+    FlowSummaryImpl::Private::Steps::summaryLocalMustFlowStep(node1
+          .(FlowSummaryNode)
+          .getSummaryNode(), node2.(FlowSummaryNode).getSummaryNode())
   }
 }
 

rust/ql/lib/codeql/rust/dataflow/internal/DataFlowImpl.qll

@@ -1030,11 +1030,9 @@ module RustDataFlow implements InputSig<Location> {
   predicate localMustFlowStep(Node node1, Node node2) {
     SsaFlow::localMustFlowStep(_, node1, node2)
     or
-    node1 =
-      unique(Node::FlowSummaryNode n1 |
-        FlowSummaryImpl::Private::Steps::summaryLocalStep(n1.getSummaryNode(),
-          node2.(Node::FlowSummaryNode).getSummaryNode(), true, _)
-      )
+    FlowSummaryImpl::Private::Steps::summaryLocalMustFlowStep(node1
+          .(Node::FlowSummaryNode)
+          .getSummaryNode(), node2.(Node::FlowSummaryNode).getSummaryNode())
   }
 
   class LambdaCallKind = Void;

shared/dataflow/codeql/dataflow/internal/FlowSummaryImpl.qll

@@ -1207,6 +1207,11 @@ module Make<
         )
       }
 
+      /** Holds if the value of `succ` is uniquely determined by the value of `pred`. */
+      predicate summaryLocalMustFlowStep(SummaryNode pred, SummaryNode succ) {
+        pred = unique(SummaryNode n1 | summaryLocalStep(n1, succ, true, _))
+      }
+
       /**
        * Holds if there is a read step of content `c` from `pred` to `succ`, which
        * is synthesized from a flow summary.