From 88dda89329330119bcb97788e84a30b2bf1cb23a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20L=C3=B6hning?= <robert.loehning@qt.io>
Date: Thu, 13 Jan 2022 21:14:23 +0100
Subject: [PATCH] Fuzzing: Add fuzzer for QJsonDocument::fromJson

Task-number: QTBUG-99799
Change-Id: If997b661da2fce04b84f94b9e66de19c9946a914
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
---
 .../qjsondocument/fromjson/CMakeLists.txt     | 27 +++++++++++++++
 .../qjsondocument/fromjson/main.cpp           | 34 +++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/CMakeLists.txt
 create mode 100644 tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/main.cpp

diff --git a/tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/CMakeLists.txt b/tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/CMakeLists.txt
new file mode 100644
index 0000000000..f79774c8d4
--- /dev/null
+++ b/tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/CMakeLists.txt
@@ -0,0 +1,27 @@
+cmake_minimum_required(VERSION 3.16)
+project(fromjson LANGUAGES CXX)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+find_package(Qt6 REQUIRED COMPONENTS Core)
+
+qt_add_executable(fromjson
+    main.cpp
+)
+
+target_link_libraries(fromjson PUBLIC
+    Qt::Core
+)
+if(DEFINED ENV{LIB_FUZZING_ENGINE})
+    target_link_libraries(fromjson PRIVATE
+        $ENV{LIB_FUZZING_ENGINE}
+    )
+else()
+    target_link_libraries(fromjson PRIVATE
+        -fsanitize=fuzzer
+    )
+endif()
diff --git a/tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/main.cpp b/tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/main.cpp
new file mode 100644
index 0000000000..df9090a551
--- /dev/null
+++ b/tests/libfuzzer/corelib/serialization/qjsondocument/fromjson/main.cpp
@@ -0,0 +1,34 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QJsonDocument>
+
+extern "C" int LLVMFuzzerTestOneInput(const char *Data, size_t Size) {
+    QJsonDocument::fromJson(QByteArray::fromRawData(Data, Size));
+    return 0;
+}