Swift: Add FieldDecl.hasQualifiedName.

Author: geoffw0

swift/ql/lib/codeql/swift/elements/decl/VarDecl.qll

@@ -9,8 +9,32 @@ class VarDecl extends Generated::VarDecl {
 }
 
 /**
- * A field declaration.
+ * A field declaration. That is, a variable declaration that is a member of a
+ * class, struct, enum or protocol.
  */
 class FieldDecl extends VarDecl {
   FieldDecl() { this = any(Decl ctx).getAMember() }
+
+  /**
+   * Holds if this field is called `fieldName` and is a member of a
+   * class, struct, extension, enum or protocol called `typeName`.
+   */
+  cached
+  predicate hasQualifiedName(string typeName, string fieldName) {
+    this.getName() = fieldName and
+    exists(Decl d |
+      d.asNominalTypeDecl().getFullName() = typeName and
+      d.getAMember() = this
+    )
+  }
+
+  /**
+   * Holds if this field is called `fieldName` and is a member of a
+   * class, struct, extension, enum or protocol called `typeName` in a module
+   * called `moduleName`.
+   */
+  predicate hasQualifiedName(string moduleName, string typeName, string fieldName) {
+    this.hasQualifiedName(typeName, fieldName) and
+    this.getModule().getFullName() = moduleName
+  }
 }