C#: Extend pre-SSA consistency tests

hvitved · hvitved · commit 98db3f89c257 · 2018-10-11T13:59:06.000+02:00
diff --git a/csharp/ql/src/semmle/code/csharp/controlflow/ControlFlowGraph.qll b/csharp/ql/src/semmle/code/csharp/controlflow/ControlFlowGraph.qll
@@ -2507,7 +2507,7 @@ module ControlFlow {
       private import PreBasicBlocks
       private import AssignableDefinitions
 
-      private class SimpleLocalScopeVariable extends LocalScopeVariable {
+      class SimpleLocalScopeVariable extends LocalScopeVariable {
         SimpleLocalScopeVariable() {
           not exists(AssignableDefinition def1, AssignableDefinition def2 |
             def1.getTarget() = this and
diff --git a/csharp/ql/test/library-tests/dataflow/ssa/PreSsaConsistency.ql b/csharp/ql/test/library-tests/dataflow/ssa/PreSsaConsistency.ql
@@ -1,28 +1,48 @@
 import csharp
 import ControlFlow::Internal
 
-predicate defReadInconsistency(AssignableRead ar, Expr e) {
-  exists(PreSsa::Definition ssaDef, AssignableDefinition def |
-    e = def.getExpr() and
-    PreSsa::firstReadSameVar(ssaDef, ar) and
-    ssaDef.getDefinition() = def and
-    not exists(Ssa::ExplicitDefinition edef |
+predicate defReadInconsistency(AssignableRead ar, Expr e, boolean b) {
+  exists(AssignableDefinition def |
+    e = def.getExpr() |
+    b = true and
+    exists(PreSsa::Definition ssaDef |
+      PreSsa::firstReadSameVar(ssaDef, ar) and
+      ssaDef.getDefinition() = def and
+      not exists(Ssa::ExplicitDefinition edef |
+        edef.getADefinition() = def and
+        edef.getAFirstRead() = ar
+      )
+    )
+    or
+    b = false and
+    exists(Ssa::ExplicitDefinition edef |
       edef.getADefinition() = def and
-      edef.getARead() = ar
+      edef.getAFirstRead() = ar and
+      def.getTarget() instanceof PreSsa::SimpleLocalScopeVariable and
+      not exists(PreSsa::Definition ssaDef |
+        PreSsa::firstReadSameVar(ssaDef, ar) and
+        ssaDef.getDefinition() = def
+      )
     )
   )
 }
 
-predicate readReadInconsistency(LocalScopeVariableRead read1, LocalScopeVariableRead read2) {
+predicate readReadInconsistency(LocalScopeVariableRead read1, LocalScopeVariableRead read2, boolean b) {
+  b = true and
   PreSsa::adjacentReadPairSameVar(read1, read2) and
   not Ssa::Internal::adjacentReadPairSameVar(read1, read2)
+  or
+  b = false and
+  Ssa::Internal::adjacentReadPairSameVar(read1, read2) and
+  read1.getTarget() instanceof PreSsa::SimpleLocalScopeVariable and
+  not PreSsa::adjacentReadPairSameVar(read1, read2)
 }
 
-from Element e1, Element e2, string s
+from Element e1, Element e2, boolean b, string s
 where
-  defReadInconsistency(e1, e2) and
-  s = "def-read inconsistency"
+  defReadInconsistency(e1, e2, b) and
+  s = "def-read inconsistency (" + b + ")"
   or
-  readReadInconsistency(e1, e2) and
-  s = "read-read inconsistency"
+  readReadInconsistency(e1, e2, b) and
+  s = "read-read inconsistency (" + b + ")"
 select e1, e2, s
