C#: Add CIL attribute tests

csharp/ql/test/library-tests/cil/attributes/Test.cs

@@ -0,0 +1,7 @@
+// semmle-extractor-options: --cil
+
+using System;
+
+class Test
+{
+}

csharp/ql/test/library-tests/cil/attributes/attribute.ql

@@ -0,0 +1,32 @@
+import semmle.code.cil.Attribute
+import semmle.code.cil.Declaration
+
+query predicate attrNoArg(string dec, string attr) {
+  exists(Declaration d, Attribute a |
+    a.getDeclaration() = d and
+    not exists(a.getAnArgument())
+  |
+    dec = d.toStringWithTypes() and
+    attr = a.toStringWithTypes()
+  )
+}
+
+query predicate attrArgNamed(string dec, string attr, string name, string value) {
+  exists(Declaration d, Attribute a |
+    a.getDeclaration() = d and
+    a.getNamedArgument(name) = value
+  |
+    dec = d.toStringWithTypes() and
+    attr = a.toStringWithTypes()
+  )
+}
+
+query predicate attrArgPositional(string dec, string attr, int index, string value) {
+  exists(Declaration d, Attribute a |
+    a.getDeclaration() = d and
+    a.getArgument(index) = value
+  |
+    dec = d.toStringWithTypes() and
+    attr = a.toStringWithTypes()
+  )
+}