Merge pull request github#4623 from tamasvajk/feature/csharp9-type-param-nullability

C#: Add type parameter ref/value type tests

Author: tamasvajk

csharp/ql/test/library-tests/csharp9/PrintAst.expected

@@ -105,3 +105,106 @@ NativeInt.cs:
 #   25|               0: [CastExpr] (...) ...
 #   25|                 1: [LocalVariableAccess] access to local variable x
 #   25|               1: [LocalVariableAccess] access to local variable v
+TypeParameterNullability.cs:
+#    1| [Interface] I1
+#    3| [Class] A2
+#    5|   5: [Method] F1
+#    5|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#    5|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#    5|       0: [Parameter] t
+#    5|     4: [BlockStmt] {...}
+#    6|   6: [Method] F2
+#    6|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#    6|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#    6|       0: [Parameter] t
+#    6|         -1: [TypeMention] T?
+#    6|           1: [TypeMention] T
+#    6|     4: [BlockStmt] {...}
+#    7|   7: [Method] F3
+#    7|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#    7|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#    7|       0: [Parameter] t
+#    7|     4: [BlockStmt] {...}
+#    8|   8: [Method] F4
+#    8|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#    8|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#    8|       0: [Parameter] t
+#    8|     4: [BlockStmt] {...}
+#    9|   9: [Method] F5
+#    9|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#    9|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#    9|       0: [Parameter] t
+#    9|     4: [BlockStmt] {...}
+#   10|   10: [Method] F6
+#   10|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   10|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   10|       0: [Parameter] t
+#   10|         -1: [TypeMention] T?
+#   10|           1: [TypeMention] T
+#   10|     4: [BlockStmt] {...}
+#   13| [Class] B2
+#-----|   3: (Base types)
+#   13|     0: [TypeMention] A2
+#   15|   5: [Method] F1
+#   15|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   15|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   15|       0: [Parameter] t
+#   15|     4: [BlockStmt] {...}
+#   16|   6: [Method] F2
+#   16|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   16|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   16|       0: [Parameter] t
+#   16|         -1: [TypeMention] T?
+#   16|           1: [TypeMention] T
+#   16|     4: [BlockStmt] {...}
+#   17|   7: [Method] F3
+#   17|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   17|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   17|       0: [Parameter] t
+#   17|     4: [BlockStmt] {...}
+#   18|   8: [Method] F4
+#   18|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   18|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   18|       0: [Parameter] t
+#   18|     4: [BlockStmt] {...}
+#   19|   9: [Method] F6
+#   19|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   19|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   19|       0: [Parameter] t
+#   19|         -1: [TypeMention] T?
+#   19|           1: [TypeMention] T
+#   19|     4: [BlockStmt] {...}
+#   22| [Class] B3
+#-----|   3: (Base types)
+#   22|     0: [TypeMention] A2
+#   24|   5: [Method] F2
+#   24|     -1: [TypeMention] Void
+#-----|     1: (Type parameters)
+#   24|       0: [TypeParameter] T
+#-----|     2: (Parameters)
+#   24|       0: [Parameter] t
+#   24|         -1: [TypeMention] T?
+#   24|           1: [TypeMention] T
+#   24|     4: [BlockStmt] {...}

csharp/ql/test/library-tests/csharp9/TypeParameterNullability.cs

@@ -0,0 +1,25 @@
+interface I1 {}
+
+class A2
+{
+    public virtual void F1<T>(T? t) { }                 // value or ref type
+    public virtual void F2<T>(T? t) where T: struct { } // value type
+    public virtual void F3<T>(T? t) where T: class { }  // ref type
+    public virtual void F4<T>(T? t) where T: A2 { }     // A2, ref type
+    public virtual void F5<T>(T? t) where T: I1 { }     // I1, value or ref type
+    public virtual void F6<T>(T? t) where T: struct, I1 { }  // I1, value type
+}
+
+class B2 : A2
+{
+    public override void F1<T>(T? t) where T: default { } // value or ref type
+    public override void F2<T>(T? t) { }                  // value type
+    public override void F3<T>(T? t) where T: class { }   // ref type
+    public override void F4<T>(T? t) where T: class { }   // A2, ref type
+    public override void F6<T>(T? t) { }                  // I1, value type
+}
+
+class B3 : A2
+{
+    public override void F2<T>(T? t) where T: struct { }  // value type
+}

csharp/ql/test/library-tests/csharp9/typeParameterNullability.expected

@@ -0,0 +1,15 @@
+refType
+| TypeParameterNullability.cs:7:28:7:28 | T |
+| TypeParameterNullability.cs:8:28:8:28 | T |
+| TypeParameterNullability.cs:17:29:17:29 | T |
+| TypeParameterNullability.cs:18:29:18:29 | T |
+valueType
+| TypeParameterNullability.cs:6:28:6:28 | T |
+| TypeParameterNullability.cs:10:28:10:28 | T |
+| TypeParameterNullability.cs:16:29:16:29 | T |
+| TypeParameterNullability.cs:19:29:19:29 | T |
+| TypeParameterNullability.cs:24:29:24:29 | T |
+valueOrRefType
+| TypeParameterNullability.cs:5:28:5:28 | T |
+| TypeParameterNullability.cs:9:28:9:28 | T |
+| TypeParameterNullability.cs:15:29:15:29 | T |

csharp/ql/test/library-tests/csharp9/typeParameterNullability.ql

@@ -0,0 +1,17 @@
+import csharp
+
+query predicate refType(TypeParameter tp) {
+  tp.fromSource() and
+  tp.isRefType()
+}
+
+query predicate valueType(TypeParameter tp) {
+  tp.fromSource() and
+  tp.isValueType()
+}
+
+query predicate valueOrRefType(TypeParameter tp) {
+  tp.fromSource() and
+  not tp.isRefType() and
+  not tp.isValueType()
+}