Update tests/fuzzer/fuzz_gltf_customjson.cc

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

.gitignore

@@ -1,4 +1,5 @@
 # CMake
+/build/
 CMakeCache.txt
 CMakeFiles
 CMakeScripts
@@ -68,8 +69,22 @@ imgui.ini
 loader_example
 tests/tester
 tests/tester_noexcept
+tests/tester_intensive_customjson
 tests/issue-97.gltf
 tests/issue-261.gltf
+tests/issue-495-external.gltf
+# Test-generated output files (written by tester.cc during test run)
+tests/Cube.gltf
+tests/Cube.bin
+tests/Cube.glb
+tests/Cube_BaseColor.png
+tests/Cube_MetallicRoughness.png
+tests/Cube_with_embedded_images.gltf
+tests/Cube_with_image_files.gltf
+tests/tmp.glb
+tests/ issue-236.gltf
+tests/ issue-236.bin
+tests/ 2x2 image  has multiple      spaces.png
 
 # unignore
 !Makefile

CMakeLists.txt

@@ -18,6 +18,7 @@ option(TINYGLTF_BUILD_TESTS "Build unit tests" OFF)
 option(TINYGLTF_HEADER_ONLY "On: header-only mode. Off: create tinygltf library(No TINYGLTF_IMPLEMENTATION required in your project)" OFF)
 option(TINYGLTF_INSTALL "Install tinygltf files during install step. Usually set to OFF if you include tinygltf through add_subdirectory()" ON)
 option(TINYGLTF_INSTALL_VENDOR "Install vendored nlohmann/json and nothings/stb headers" ON)
+option(TINYGLTF_USE_CUSTOM_JSON "Use the built-in fast JSON parser (tinygltf_json.h) instead of nlohmann/json" OFF)
 
 if (TINYGLTF_BUILD_LOADER_EXAMPLE)
   add_executable(loader_example
@@ -46,6 +47,24 @@ if (TINYGLTF_BUILD_TESTS)
     ${CMAKE_CURRENT_SOURCE_DIR}/tests
   )
   add_test(NAME tester COMMAND tester WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests)
+
+  # Build and run tests with the custom JSON backend enabled to catch regressions
+  add_executable(tester_customjson tests/tester.cc)
+  target_include_directories(tester_customjson PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/tests
+  )
+  target_compile_definitions(tester_customjson PRIVATE TINYGLTF_USE_CUSTOM_JSON)
+  add_test(NAME tester_customjson COMMAND tester_customjson WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests)
+
+  # Intensive parser tests for the custom JSON backend
+  add_executable(tester_intensive_customjson tests/tester_intensive_customjson.cc)
+  target_include_directories(tester_intensive_customjson PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/tests
+  )
+  target_compile_definitions(tester_intensive_customjson PRIVATE TINYGLTF_USE_CUSTOM_JSON)
+  add_test(NAME tester_intensive_customjson COMMAND tester_intensive_customjson WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests)
 endif (TINYGLTF_BUILD_TESTS)
 
 #
@@ -71,6 +90,14 @@ else (TINYGLTF_HEADER_ONLY)
           )
 endif (TINYGLTF_HEADER_ONLY)
 
+if (TINYGLTF_USE_CUSTOM_JSON)
+  if (TINYGLTF_HEADER_ONLY)
+    target_compile_definitions(tinygltf INTERFACE TINYGLTF_USE_CUSTOM_JSON)
+  else ()
+    target_compile_definitions(tinygltf PUBLIC TINYGLTF_USE_CUSTOM_JSON)
+  endif ()
+endif ()
+
 if (TINYGLTF_INSTALL)
   install(TARGETS tinygltf EXPORT tinygltfTargets)
   install(EXPORT tinygltfTargets NAMESPACE tinygltf:: FILE TinyGLTFTargets.cmake DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/tinygltf)
@@ -80,6 +107,7 @@ if (TINYGLTF_INSTALL)
 
   INSTALL ( FILES
     tiny_gltf.h
+    tinygltf_json.h
     ${TINYGLTF_EXTRA_SOUECES}
     DESTINATION
     include

README.md

@@ -26,8 +26,6 @@ Currently TinyGLTF is stable and maintenance mode. No drastic changes and featur
 
 ## Builds
 
-[![Build status](https://ci.appveyor.com/api/projects/status/warngenu9wjjhlm8?svg=true)](https://ci.appveyor.com/project/syoyo/tinygltf)
-
 ![C/C++ CI](https://github.com/syoyo/tinygltf/workflows/C/C++%20CI/badge.svg)
 
 ## Features

appveyor.yml

@@ -1,18 +0,0 @@
-version: 0.9.{build}
-
-image:
-  - Visual Studio 2015
-
-# scripts that runs after repo cloning.
-install:
-  - vcsetup.bat
-
-platform: x64
-configuration: Release
-
-build:
-  parallel: true
-  project: TinyGLTFSolution.sln
-
-after_build:
-  - examples.bat

tests/Makefile

@@ -4,3 +4,4 @@
 all: ../tiny_gltf.h
 	clang++  -I../ $(EXTRA_CXXFLAGS) -std=c++11 -g -O0 -o tester tester.cc
 	clang++ -DTINYGLTF_NOEXCEPTION -I../ $(EXTRA_CXXFLAGS) -std=c++11 -g -O0 -o tester_noexcept tester.cc
+	clang++ -DTINYGLTF_USE_CUSTOM_JSON -I../ $(EXTRA_CXXFLAGS) -std=c++11 -g -O0 -o tester_intensive_customjson tester_intensive_customjson.cc

tests/fuzzer/README.md

@@ -4,9 +4,14 @@ Do fuzzing test for TinyGLTF API.
 
 ## Supported API
 
-* [x] LoadASCIIFromMemory
+* [x] LoadASCIIFromString
 * [ ] LoadBinaryFromMemory
 
+### Custom JSON backend (`tinygltf_json.h`)
+
+* [x] LoadASCIIFromString
+* [x] LoadBinaryFromMemory
+
 ## Requirements
 
 * meson
@@ -36,11 +41,17 @@ $ cd build
 $ ninja
 ```
 
+This builds two fuzzers:
+
+* `fuzz_gltf` – default nlohmann/json backend
+* `fuzz_gltf_customjson` – custom `tinygltf_json.h` backend (tests both ASCII and binary parsing paths)
+
 ## How to run
 
 Increase memory limit. e.g. `-rss_limit_mb=50000`
 
 ```
 $ ./fuzz_gltf -rss_limit_mb=20000 -jobs 4
+$ ./fuzz_gltf_customjson -rss_limit_mb=20000 -jobs 4
 ```
 

tests/fuzzer/fuzz_gltf_customjson.cc

@@ -0,0 +1,76 @@
+/*
+ * LLVM libFuzzer harness for tinygltf with the custom JSON backend
+ * (tinygltf_json.h).
+ *
+ * Exercises:
+ *   1. LoadASCIIFromString  – glTF JSON parsing
+ *   2. LoadBinaryFromMemory – GLB binary parsing
+ *
+ * Build (clang with libFuzzer):
+ *   clang++ -std=c++11 -fsanitize=address,fuzzer \
+ *           -DTINYGLTF_USE_CUSTOM_JSON           \
+ *           -I../../ fuzz_gltf_customjson.cc      \
+ *           -o fuzz_gltf_customjson
+ *
+ * Run:
+ *   ./fuzz_gltf_customjson -rss_limit_mb=20000 -jobs 4
+ */
+
+#include <cstdint>
+#include <cstring>
+
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#define TINYGLTF_IMPLEMENTATION
+#ifndef TINYGLTF_USE_CUSTOM_JSON
+#define TINYGLTF_USE_CUSTOM_JSON
+#endif
+#include "tiny_gltf.h"
+
+/* Fuzz the ASCII (JSON) parser path */
+static void fuzz_ascii(const uint8_t *data, size_t size) {
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  std::string err;
+  std::string warn;
+
+  const char *str = reinterpret_cast<const char *>(data);
+
+  bool ret =
+      ctx.LoadASCIIFromString(&model, &err, &warn, str,
+                              static_cast<unsigned int>(size), /* base_dir */ "");
+  (void)ret;
+}
+
+/* Fuzz the binary (GLB) parser path */
+static void fuzz_binary(const uint8_t *data, size_t size) {
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  std::string err;
+  std::string warn;
+
+  bool ret = ctx.LoadBinaryFromMemory(&model, &err, &warn, data,
+                                      static_cast<unsigned int>(size),
+                                      /* base_dir */ "");
+  (void)ret;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  if (size == 0) return 0;
+
+  /* Use the lowest bit of the first byte to select the parse path.
+   * The remaining bits are left for the fuzzer engine to explore;
+   * additional paths (e.g. LoadASCIIFromFile, check_sections flags)
+   * can be added here in the future using more selector bits. */
+  uint8_t selector = data[0];
+  const uint8_t *payload = data + 1;
+  size_t payload_size = size - 1;
+
+  if (selector & 1) {
+    fuzz_binary(payload, payload_size);
+  } else {
+    fuzz_ascii(payload, payload_size);
+  }
+
+  return 0;
+}

tests/fuzzer/meson.build

@@ -7,3 +7,9 @@ executable('fuzz_gltf',
   cpp_args : '-fsanitize=address,fuzzer',
   link_args : '-fsanitize=address,fuzzer' )
 
+executable('fuzz_gltf_customjson',
+  'fuzz_gltf_customjson.cc',
+  include_directories : incdirs,
+  cpp_args : ['-fsanitize=address,fuzzer', '-DTINYGLTF_USE_CUSTOM_JSON'],
+  link_args : '-fsanitize=address,fuzzer' )
+

tiny_gltf.h

@@ -1711,7 +1711,11 @@ class TinyGLTF {
 #endif  // __GNUC__
 
 #ifndef TINYGLTF_NO_INCLUDE_JSON
-#ifndef TINYGLTF_USE_RAPIDJSON
+#ifdef TINYGLTF_USE_CUSTOM_JSON
+#ifndef TINYGLTF_NO_INCLUDE_CUSTOM_JSON
+#include "tinygltf_json.h"
+#endif
+#elif !defined(TINYGLTF_USE_RAPIDJSON)
 #include "json.hpp"
 #else
 #ifndef TINYGLTF_NO_INCLUDE_RAPIDJSON
@@ -1799,7 +1803,10 @@ class TinyGLTF {
 
 namespace tinygltf {
 namespace detail {
-#ifdef TINYGLTF_USE_RAPIDJSON
+#ifdef TINYGLTF_USE_CUSTOM_JSON
+// Types and JsonParse are provided by tinygltf_json.h (already included above)
+// via 'namespace tinygltf { namespace detail { ... } }' declarations.
+#elif defined(TINYGLTF_USE_RAPIDJSON)
 
 #ifdef TINYGLTF_USE_RAPIDJSON_CRTALLOCATOR
 // This uses the RapidJSON CRTAllocator.  It is thread safe and multiple
@@ -1871,6 +1878,7 @@ using json_const_array_iterator = json_const_iterator;
 using JsonDocument = json;
 #endif
 
+#ifndef TINYGLTF_USE_CUSTOM_JSON
 void JsonParse(JsonDocument &doc, const char *str, size_t length,
                bool throwExc = false) {
 #ifdef TINYGLTF_USE_RAPIDJSON
@@ -1880,6 +1888,7 @@ void JsonParse(JsonDocument &doc, const char *str, size_t length,
   doc = detail::json::parse(str, str + length, nullptr, throwExc);
 #endif
 }
+#endif  // !TINYGLTF_USE_CUSTOM_JSON
 }  // namespace detail
 }  // namespace tinygltf
 
@@ -2451,9 +2460,8 @@ inline unsigned char from_hex(unsigned char ch) {
 }
 
 static const std::string urldecode(const std::string &str) {
-  using namespace std;
-  string result;
-  string::size_type i;
+  std::string result;
+  std::string::size_type i;
   for (i = 0; i < str.size(); ++i) {
     if (str[i] == '+') {
       result += ' ';
@@ -3437,6 +3445,7 @@ bool DecodeDataURI(std::vector<unsigned char> *out, std::string &mime_type,
   return true;
 }
 
+#ifndef TINYGLTF_USE_CUSTOM_JSON
 namespace detail {
 bool GetInt(const detail::json &o, int &val) {
 #ifdef TINYGLTF_USE_RAPIDJSON
@@ -3660,6 +3669,7 @@ std::string JsonToString(const detail::json &o, int spacing = -1) {
 }
 
 }  // namespace detail
+#endif  // !TINYGLTF_USE_CUSTOM_JSON
 
 static bool ParseJsonAsValue(Value *ret, const detail::json &o) {
   Value val{};
@@ -6963,6 +6973,7 @@ bool TinyGLTF::LoadBinaryFromFile(Model *model, std::string *err,
 ///////////////////////
 // GLTF Serialization
 ///////////////////////
+#ifndef TINYGLTF_USE_CUSTOM_JSON
 namespace detail {
 detail::json JsonFromString(const char *s) {
 #ifdef TINYGLTF_USE_RAPIDJSON
@@ -7035,6 +7046,7 @@ void JsonReserveArray(detail::json &o, size_t s) {
   (void)(s);
 }
 }  // namespace detail
+#endif  // !TINYGLTF_USE_CUSTOM_JSON
 
 // typedef std::pair<std::string, detail::json> json_object_pair;