C#: Sign analysis testcase for unsigned right shift.

Author: michaelnebel

csharp/ql/test/library-tests/csharp11/SignAnalysis.cs

@@ -0,0 +1,42 @@
+public class MySignAnalysis
+{
+
+    public void UnsignedRightShiftSign(int x, int y)
+    {
+        int z;
+        if (x == 0)
+        {
+            z = x >>> y;
+        }
+
+        if (y == 0)
+        {
+            z = x >>> y;
+        }
+
+        if (x > 0 && y == 0)
+        {
+            z = x >>> y;
+        }
+
+        if (x > 0 && y > 0)
+        {
+            z = x >>> y;
+        }
+
+        if (x > 0 && y < 0)
+        {
+            z = x >>> y;
+        }
+
+        if (x < 0 && y > 0)
+        {
+            z = x >>> y;
+        }
+
+        if (x < 0 && y < 0)
+        {
+            z = x >>> y;
+        }
+    }
+}

csharp/ql/test/library-tests/csharp11/signAnalysis.expected

@@ -0,0 +1,7 @@
+| SignAnalysis.cs:9:17:9:23 | ... >>> ... | 0 |
+| SignAnalysis.cs:14:17:14:23 | ... >>> ... | + - 0 |
+| SignAnalysis.cs:19:17:19:23 | ... >>> ... | + |
+| SignAnalysis.cs:24:17:24:23 | ... >>> ... | + 0 |
+| SignAnalysis.cs:29:17:29:23 | ... >>> ... | + 0 |
+| SignAnalysis.cs:34:17:34:23 | ... >>> ... | + - |
+| SignAnalysis.cs:39:17:39:23 | ... >>> ... | + - |

csharp/ql/test/library-tests/csharp11/signAnalysis.ql

@@ -0,0 +1,9 @@
+import csharp
+import semmle.code.csharp.dataflow.internal.rangeanalysis.SignAnalysisCommon as Common
+
+from ControlFlow::Nodes::ExprNode e, Expr expr
+where
+  e.getExpr() = expr and
+  expr.getFile().getStem() = "SignAnalysis" and
+  expr instanceof UnsignedRightShiftExpr
+select e, strictconcat(string s | s = Common::exprSign(e).toString() | s, " ")