From 0e376b32d2968382730cdfd9af1affee5b0984c8 Mon Sep 17 00:00:00 2001
From: Anders Schack-Mulligen <aschackmull@github.com>
Date: Tue, 13 Sep 2022 13:14:22 +0200
Subject: [PATCH] Java: extend typeflow tests to cover union types.

---
 .../library-tests/typeflow/UnionTypes.java    | 54 +++++++++++++++++++
 .../library-tests/typeflow/typeflow.expected  |  1 +
 .../typeflow/uniontypeflow.expected           | 24 +++++++++
 .../library-tests/typeflow/uniontypeflow.ql   | 10 ++++
 4 files changed, 89 insertions(+)
 create mode 100644 java/ql/test/library-tests/typeflow/UnionTypes.java
 create mode 100644 java/ql/test/library-tests/typeflow/uniontypeflow.expected
 create mode 100644 java/ql/test/library-tests/typeflow/uniontypeflow.ql

diff --git a/java/ql/test/library-tests/typeflow/UnionTypes.java b/java/ql/test/library-tests/typeflow/UnionTypes.java
new file mode 100644
index 00000000000..a82b3828d2f
--- /dev/null
+++ b/java/ql/test/library-tests/typeflow/UnionTypes.java
@@ -0,0 +1,54 @@
+import java.util.*;
+import java.util.concurrent.*;
+
+public class UnionTypes {
+  public void m1() {
+    m1_map_put(new LinkedHashMap<>(), "k", "v");
+    m1_map_put(new ConcurrentHashMap<>(), "k", "v");
+  }
+
+  private void m1_map_put(Map<String, String> m, String k, String v) {
+    m.put(k, v);
+  }
+
+  static class Sup { }
+  interface Inter { }
+
+  static class A1 extends Sup implements Inter { }
+  static class A2 extends Sup implements Inter { }
+  static class A3 extends Sup { }
+  static class A4 extends Sup implements Inter { }
+  static class A2sub extends A2 { }
+
+  private void m2(boolean b) {
+    scc1(new A1(), 10);
+    Sup x = b ? new A2() : new A3();
+    scc2(x, 10);
+  }
+
+  private void scc1(Sup x1, int i) {
+    scc2(x1, i);
+  }
+
+  private void scc2(Sup x2, int i) {
+    scc3(x2, i);
+  }
+
+  private void scc3(Sup x3, int i) {
+    next(x3);
+    if (i > 0)
+      scc1(x3, --i);
+  }
+
+  private void next(Sup x) {
+    if (x instanceof Inter) {
+      x.hashCode();
+    }
+  }
+
+  void m3(Object d) {
+    if (d instanceof A1 || d instanceof A2 || d instanceof A3) {
+      d.hashCode();
+    }
+  }
+}
diff --git a/java/ql/test/library-tests/typeflow/typeflow.expected b/java/ql/test/library-tests/typeflow/typeflow.expected
index 1f879fe37ea..021d04b55d3 100644
--- a/java/ql/test/library-tests/typeflow/typeflow.expected
+++ b/java/ql/test/library-tests/typeflow/typeflow.expected
@@ -13,3 +13,4 @@
 | A.java:67:22:67:22 | x | Integer | false |
 | A.java:70:23:70:24 | x2 | Integer | false |
 | A.java:92:18:92:18 | n | Integer | false |
+| UnionTypes.java:45:7:45:7 | x | Inter | false |
diff --git a/java/ql/test/library-tests/typeflow/uniontypeflow.expected b/java/ql/test/library-tests/typeflow/uniontypeflow.expected
new file mode 100644
index 00000000000..7c595175301
--- /dev/null
+++ b/java/ql/test/library-tests/typeflow/uniontypeflow.expected
@@ -0,0 +1,24 @@
+| UnionTypes.java:11:5:11:5 | m | 2 | ConcurrentHashMap<String,String> | false |
+| UnionTypes.java:11:5:11:5 | m | 2 | LinkedHashMap<String,String> | false |
+| UnionTypes.java:26:10:26:10 | x | 2 | A2 | true |
+| UnionTypes.java:26:10:26:10 | x | 2 | A3 | false |
+| UnionTypes.java:30:10:30:11 | x1 | 3 | A1 | false |
+| UnionTypes.java:30:10:30:11 | x1 | 3 | A2 | true |
+| UnionTypes.java:30:10:30:11 | x1 | 3 | A3 | false |
+| UnionTypes.java:34:10:34:11 | x2 | 3 | A1 | false |
+| UnionTypes.java:34:10:34:11 | x2 | 3 | A2 | true |
+| UnionTypes.java:34:10:34:11 | x2 | 3 | A3 | false |
+| UnionTypes.java:38:10:38:11 | x3 | 3 | A1 | false |
+| UnionTypes.java:38:10:38:11 | x3 | 3 | A2 | true |
+| UnionTypes.java:38:10:38:11 | x3 | 3 | A3 | false |
+| UnionTypes.java:40:12:40:13 | x3 | 3 | A1 | false |
+| UnionTypes.java:40:12:40:13 | x3 | 3 | A2 | true |
+| UnionTypes.java:40:12:40:13 | x3 | 3 | A3 | false |
+| UnionTypes.java:44:9:44:9 | x | 3 | A1 | false |
+| UnionTypes.java:44:9:44:9 | x | 3 | A2 | true |
+| UnionTypes.java:44:9:44:9 | x | 3 | A3 | false |
+| UnionTypes.java:45:7:45:7 | x | 2 | A1 | false |
+| UnionTypes.java:45:7:45:7 | x | 2 | A2 | true |
+| UnionTypes.java:51:7:51:7 | d | 3 | A1 | false |
+| UnionTypes.java:51:7:51:7 | d | 3 | A2 | false |
+| UnionTypes.java:51:7:51:7 | d | 3 | A3 | false |
diff --git a/java/ql/test/library-tests/typeflow/uniontypeflow.ql b/java/ql/test/library-tests/typeflow/uniontypeflow.ql
new file mode 100644
index 00000000000..769ac89172c
--- /dev/null
+++ b/java/ql/test/library-tests/typeflow/uniontypeflow.ql
@@ -0,0 +1,10 @@
+import java
+import semmle.code.java.dataflow.TypeFlow
+
+int countUnionTypes(Expr e) {
+  result = strictcount(RefType t, boolean exact | exprUnionTypeFlow(e, t, exact))
+}
+
+from RValue e, RefType t, boolean exact
+where exprUnionTypeFlow(e, t, exact)
+select e, countUnionTypes(e), t.toString(), exact