Dataflow: Minor perf fix for single config wrapper.

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/experimental/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

go/ql/lib/semmle/go/dataflow/internal/DataFlowImplForStringsNewReplacer.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl3.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl4.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl5.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl6.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl3.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl4.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl2.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

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

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImpl1.qll

@@ -264,6 +264,8 @@ private Configuration getConfig(TConfigState state) { state = TMkConfigState(res
 
 private FlowState getState(TConfigState state) { state = TMkConfigState(_, result) }
 
+private predicate singleConfiguration() { 1 = strictcount(Configuration c) }
+
 private module Config implements FullStateConfigSig {
   class FlowState = TConfigState;
 
@@ -292,13 +294,18 @@ private module Config implements FullStateConfigSig {
 
   predicate isBarrierOut(Node node) { any(Configuration config).isBarrierOut(node) }
 
-  predicate isAdditionalFlowStep(Node node1, Node node2) { none() }
+  predicate isAdditionalFlowStep(Node node1, Node node2) {
+    singleConfiguration() and
+    any(Configuration config).isAdditionalFlowStep(node1, node2)
+  }
 
   predicate isAdditionalFlowStep(Node node1, FlowState state1, Node node2, FlowState state2) {
     getConfig(state1).isAdditionalFlowStep(node1, getState(state1), node2, getState(state2)) and
     getConfig(state2) = getConfig(state1)
     or
-    getConfig(state1).isAdditionalFlowStep(node1, node2) and state2 = state1
+    not singleConfiguration() and
+    getConfig(state1).isAdditionalFlowStep(node1, node2) and
+    state2 = state1
   }
 
   predicate allowImplicitRead(Node node, ContentSet c) {