Data flow: Fix bad join order in getReturnPosition()

hvitved · hvitved · commit b3af3ad12f7d · 2020-02-06T19:06:40.000+01:00
Joining on the enclosing callable before the kind is crucial, as witnessed by this pipeline:

```
[2020-02-06 17:58:21] (1086s) Starting to evaluate predicate DataFlowImplCommon::getReturnPosition#ff/2@83c546
[2020-02-06 18:53:16] (4382s) Tuple counts for DataFlowImplCommon::getReturnPosition#ff:
                      385478      ~1%     {3} r1 = SCAN DataFlowImplCommon::Cached::TReturnPosition0#fff@staged_ext AS I OUTPUT I.&lt;2&gt;, I.&lt;0&gt;, I.&lt;1&gt;
                      385478      ~2%     {3} r2 = JOIN r1 WITH DataFlowImplCommon::Cached::TReturnPosition0#fff_2#join_rhs AS R ON FIRST 1 OUTPUT r1.&lt;2&gt;, r1.&lt;1&gt;, r1.&lt;0&gt;
                      58638116860 ~0%     {3} r3 = JOIN r2 WITH DataFlowImplCommon::ReturnNodeExt::getKind_dispred#ff_10#join_rhs AS R ON FIRST 1 OUTPUT R.&lt;1&gt;, r2.&lt;1&gt;, r2.&lt;2&gt;
                      914049      ~0%     {2} r4 = JOIN r3 WITH DataFlowImplCommon::returnNodeGetEnclosingCallable#ff AS R ON FIRST 2 OUTPUT r3.&lt;0&gt;, r3.&lt;2&gt;
                                          return r4
```
diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll
@@ -753,9 +753,15 @@ private DataFlowCallable returnNodeGetEnclosingCallable(ReturnNodeExt ret) {
   result = ret.getEnclosingCallable()
 }
 
+pragma[noinline]
+private ReturnPosition getReturnPosition0(ReturnNodeExt ret, ReturnKindExt kind) {
+  result.getCallable() = returnNodeGetEnclosingCallable(ret) and
+  kind = result.getKind()
+}
+
 pragma[noinline]
 ReturnPosition getReturnPosition(ReturnNodeExt ret) {
-  result = TReturnPosition0(returnNodeGetEnclosingCallable(ret), ret.getKind())
+  result = getReturnPosition0(ret, ret.getKind())
 }
 
 bindingset[cc, callable]
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll
@@ -753,9 +753,15 @@ private DataFlowCallable returnNodeGetEnclosingCallable(ReturnNodeExt ret) {
   result = ret.getEnclosingCallable()
 }
 
+pragma[noinline]
+private ReturnPosition getReturnPosition0(ReturnNodeExt ret, ReturnKindExt kind) {
+  result.getCallable() = returnNodeGetEnclosingCallable(ret) and
+  kind = result.getKind()
+}
+
 pragma[noinline]
 ReturnPosition getReturnPosition(ReturnNodeExt ret) {
-  result = TReturnPosition0(returnNodeGetEnclosingCallable(ret), ret.getKind())
+  result = getReturnPosition0(ret, ret.getKind())
 }
 
 bindingset[cc, callable]
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll
@@ -753,9 +753,15 @@ private DataFlowCallable returnNodeGetEnclosingCallable(ReturnNodeExt ret) {
   result = ret.getEnclosingCallable()
 }
 
+pragma[noinline]
+private ReturnPosition getReturnPosition0(ReturnNodeExt ret, ReturnKindExt kind) {
+  result.getCallable() = returnNodeGetEnclosingCallable(ret) and
+  kind = result.getKind()
+}
+
 pragma[noinline]
 ReturnPosition getReturnPosition(ReturnNodeExt ret) {
-  result = TReturnPosition0(returnNodeGetEnclosingCallable(ret), ret.getKind())
+  result = getReturnPosition0(ret, ret.getKind())
 }
 
 bindingset[cc, callable]
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll
@@ -753,9 +753,15 @@ private DataFlowCallable returnNodeGetEnclosingCallable(ReturnNodeExt ret) {
   result = ret.getEnclosingCallable()
 }
 
+pragma[noinline]
+private ReturnPosition getReturnPosition0(ReturnNodeExt ret, ReturnKindExt kind) {
+  result.getCallable() = returnNodeGetEnclosingCallable(ret) and
+  kind = result.getKind()
+}
+
 pragma[noinline]
 ReturnPosition getReturnPosition(ReturnNodeExt ret) {
-  result = TReturnPosition0(returnNodeGetEnclosingCallable(ret), ret.getKind())
+  result = getReturnPosition0(ret, ret.getKind())
 }
 
 bindingset[cc, callable]
