Fuzztest clean-ups

.github/workflows/ci-fuzztest.yml

@@ -35,10 +35,6 @@ jobs:
           codec-dav1d: "LOCAL"
           libxml2: "LOCAL"
           libyuv: ${{ matrix.libyuv }}
-      - name: Build fuzztest
-        if: steps.setup.outputs.ext-cache-hit != 'true'
-        working-directory: ./ext
-        run: bash -e fuzztest.cmd
 
       - name: Prepare libavif (cmake)
         run: >
@@ -52,7 +48,6 @@ jobs:
           -DAVIF_ENABLE_EXPERIMENTAL_YCGCO_R=ON
           -DAVIF_ENABLE_EXPERIMENTAL_MINI=ON
           -DAVIF_ENABLE_EXPERIMENTAL_SAMPLE_TRANSFORM=ON
-          -DAVIF_ENABLE_FUZZTEST=ON
           -DAVIF_LOCAL_FUZZTEST=ON
           -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
           -DAVIF_ENABLE_WERROR=ON

CMakeLists.txt

@@ -142,9 +142,6 @@ option(
     "Build tests that compare encoding outputs to golden files. Needs AVIF_BUILD_APPS=ON and AVIF_BUILD_TESTS=ON, and depends on MP4box which can be built with ext/mp4box.sh"
     OFF
 )
-option(AVIF_ENABLE_FUZZTEST "Build avif fuzztest targets. Requires Google FuzzTest. Has no effect unless AVIF_BUILD_TESTS is ON."
-       OFF
-)
 option(
     AVIF_LOCAL_FUZZTEST
     "Build the Google FuzzTest framework by providing your own copy of the repo in ext/fuzztest (see Local Builds in README). CMake must be at least 3.25."
@@ -570,7 +567,7 @@ if(NOT AVIF_CODEC_AOM_ENABLED
     message(WARNING "libavif: No decoding library is enabled.")
 endif()
 
-if(AVIF_LIB_USE_CXX OR AVIF_BUILD_APPS OR (AVIF_BUILD_TESTS AND (AVIF_ENABLE_FUZZTEST OR AVIF_GTEST)))
+if(AVIF_LIB_USE_CXX OR AVIF_BUILD_APPS OR (AVIF_BUILD_TESTS AND (AVIF_LOCAL_FUZZTEST OR AVIF_GTEST)))
     enable_language(CXX)
     if(AVIF_ENABLE_NODISCARD)
         # [[nodiscard]] requires C++17.
@@ -647,7 +644,7 @@ if(NOT SKIP_INSTALL_ALL)
     include(GNUInstallDirs)
 endif()
 
-if(AVIF_BUILD_APPS OR (AVIF_BUILD_TESTS AND (AVIF_ENABLE_FUZZTEST OR AVIF_GTEST)))
+if(AVIF_BUILD_APPS OR (AVIF_BUILD_TESTS AND (AVIF_LOCAL_FUZZTEST OR AVIF_GTEST)))
     if(AVIF_ZLIBPNG STREQUAL "OFF")
         message(FATAL_ERROR "libavif: AVIF_ZLIBPNG cannot be OFF when AVIF_BUILD_APPS or AVIF_BUILD_TESTS is ON")
     elseif(AVIF_ZLIBPNG STREQUAL "SYSTEM")

cmake/Modules/LocalFuzztest.cmake

@@ -0,0 +1,32 @@
+set(AVIF_LOCAL_FUZZTEST_TAG "078ea0871cc96d3a69bad406577f176a4fa14ae9")
+
+set(FUZZTEST_SOURCE_DIR "${AVIF_SOURCE_DIR}/ext/fuzztest")
+
+if(EXISTS "${FUZZTEST_SOURCE_DIR}")
+    message(STATUS "libavif(AVIF_LOCAL_FUZZTEST=ON): folder found at ${FUZZTEST_SOURCE_DIR}")
+    set(FUZZTEST_BINARY_DIR "${FUZZTEST_SOURCE_DIR}/build.libavif")
+else()
+    message(STATUS "libavif(AVIF_LIBYUV=LOCAL): compiled library not found at ${LIB_FILENAME}; using FetchContent")
+
+    message(CHECK_START "libavif(AVIF_LOCAL_FUZZTEST=ON): configuring fuzztest")
+
+    set(FUZZTEST_SOURCE_DIR "${FETCHCONTENT_BASE_DIR}/fuzztest-src")
+    set(FUZZTEST_BINARY_DIR "${FETCHCONTENT_BASE_DIR}/fuzztest-build")
+    FetchContent_Declare(
+        fuzztest
+        GIT_REPOSITORY "https://github.com/google/fuzztest.git"
+        BINARY_DIR "${FUZZTEST_BINARY_DIR}"
+        GIT_TAG "${AVIF_LOCAL_FUZZTEST_TAG}"
+        # Fixes for https://github.com/google/fuzztest/issues/1124
+        PATCH_COMMAND
+            sed -i.bak -e "s/-fsanitize=address//g" cmake/FuzzTestFlagSetup.cmake && sed -i.bak -e "s/-DADDRESS_SANITIZER//g"
+            cmake/FuzzTestFlagSetup.cmake &&
+            # Fixes for https://github.com/google/fuzztest/issues/1125
+            sed -i.bak -e "s/if (IsEnginePlaceholderInput(data))/if (data.size() == 0)/" fuzztest/internal/compatibility_mode.cc
+            && sed -i.bak -e "s/set(GTEST_HAS_ABSL ON)/set(GTEST_HAS_ABSL OFF)/" cmake/BuildDependencies.cmake
+    )
+
+    message(CHECK_PASS "complete")
+endif()
+
+avif_fetchcontent_populate_cmake(fuzztest)

ext/fuzztest.cmd

@@ -15,8 +15,8 @@ git checkout 078ea0871cc96d3a69bad406577f176a4fa14ae9
 sed -i 's/-fsanitize=address//g' ./cmake/FuzzTestFlagSetup.cmake
 sed -i 's/-DADDRESS_SANITIZER//g' ./cmake/FuzzTestFlagSetup.cmake
 : # Fixes for https://github.com/google/fuzztest/issues/1125
-sed -i 's/if (IsEnginePlaceholderInput(data)) return;/if (data.size() == 0) return;/g' ./fuzztest/internal/compatibility_mode.cc
-sed -i 's/set(GTEST_HAS_ABSL ON)/set(GTEST_HAS_ABSL OFF)/g' ./cmake/BuildDependencies.cmake
+sed -i 's/if (IsEnginePlaceholderInput(data))/if (data.size() == 0)/' ./fuzztest/internal/compatibility_mode.cc
+sed -i 's/set(GTEST_HAS_ABSL ON)/set(GTEST_HAS_ABSL OFF)/' ./cmake/BuildDependencies.cmake
 
 : # fuzztest is built by the main CMake project through add_subdirectory as recommended at:
 : # https://github.com/google/fuzztest/blob/main/doc/quickstart-cmake.md

tests/CMakeLists.txt

@@ -43,7 +43,7 @@ foreach(AVIFYUV_MODE limited rgb) # Modes drift and premultiply take more than 2
     add_test(NAME avifyuv_${AVIFYUV_MODE} COMMAND avifyuv -m ${AVIFYUV_MODE})
 endforeach()
 
-if(AVIF_ENABLE_FUZZTEST OR AVIF_GTEST OR AVIF_BUILD_APPS)
+if(AVIF_LOCAL_FUZZTEST OR AVIF_GTEST OR AVIF_BUILD_APPS)
     add_library(aviftest_helpers OBJECT gtest/aviftest_helpers.cc)
     target_link_libraries(aviftest_helpers PUBLIC avif_apps avif)
     target_link_libraries(aviftest_helpers PRIVATE avif_enable_warnings)
@@ -169,42 +169,35 @@ endif()
 ################################################################################
 # Experimental FuzzTest support (Linux only)
 
-if(AVIF_ENABLE_FUZZTEST)
+if(AVIF_LOCAL_FUZZTEST)
     # Adds a fuzztest from file TEST_NAME.cc located in the gtest folder. Extra arguments
     # are considered as extra source files.
     macro(add_avif_fuzztest TEST_NAME)
         add_executable(${TEST_NAME} gtest/${TEST_NAME}.cc ${ARGN})
         # FuzzTest bundles GoogleTest so no need to link to gtest librairies.
-        target_link_libraries(${TEST_NAME} PRIVATE avif_fuzztest_helpers aviftest_helpers_internal avif_enable_warnings)
+        target_link_libraries(${TEST_NAME} PRIVATE avif_fuzztest_helpers aviftest_helpers_internal)
         link_fuzztest(${TEST_NAME})
         add_test(NAME ${TEST_NAME} COMMAND ${TEST_NAME} --stack_limit_kb=512)
         set_property(TEST ${TEST_NAME} PROPERTY ENVIRONMENT "TEST_DATA_DIRS=${CMAKE_CURRENT_SOURCE_DIR}/data/")
     endmacro()
 
-    if(AVIF_LOCAL_FUZZTEST)
-        # Run ext/fuzztest.cmd first.
-        # Recommended top-level CMake options:
-        #   -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DAVIF_CODEC_DAV1D=ON -DAVIF_ENABLE_WERROR=OFF
-        # Reproducing a failure can be done by setting the environment variable
-        #   FUZZTEST_REPLAY=/path/to/repro_file.test
-        # and running one of the targets below.
-        # See https://github.com/google/fuzztest/blob/main/doc/quickstart-cmake.md
-        # Note: There are compiler warnings in the FuzzTest headers. Add the
-        # ext/fuzztest subdirectory with the SYSTEM directory property set to
-        # true so that warnings in its headers are suppressed.
-        if(CMAKE_VERSION VERSION_LESS 3.25.0)
-            message(FATAL_ERROR "CMake must be at least 3.25 to pass the SYSTEM argument to add_subdirectory(), bailing out")
-        endif()
-        # Add the fuzztest project. Note this may add some tests which may not be built because of EXCLUDE_FROM_ALL and will
-        # therefore fail. They can be ignored by adding them to CTestCustom.cmake
-        # See https://gitlab.kitware.com/cmake/cmake/-/issues/20212
-        add_subdirectory(${AVIF_SOURCE_DIR}/ext/fuzztest ${AVIF_SOURCE_DIR}/ext/fuzztest/build.libavif EXCLUDE_FROM_ALL SYSTEM)
-    else()
-        message(
-            FATAL_ERROR
-                "fuzztest: Installed FuzzTest is not supported, please set AVIF_LOCAL_FUZZTEST=ON or AVIF_ENABLE_FUZZTEST=OFF"
-        )
+    # Recommended top-level CMake options:
+    #   -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DAVIF_CODEC_DAV1D=ON -DAVIF_ENABLE_WERROR=OFF
+    # Reproducing a failure can be done by setting the environment variable
+    #   FUZZTEST_REPLAY=/path/to/repro_file.test
+    # and running one of the targets below.
+    # See https://github.com/google/fuzztest/blob/main/doc/quickstart-cmake.md
+    # Note: There are compiler warnings in the FuzzTest headers. Add the
+    # ext/fuzztest subdirectory with the SYSTEM directory property set to
+    # true so that warnings in its headers are suppressed.
+    if(CMAKE_VERSION VERSION_LESS 3.25.0)
+        message(FATAL_ERROR "CMake must be at least 3.25 to pass the SYSTEM argument to add_subdirectory(), bailing out")
     endif()
+    # Add the fuzztest project. Note this may add some tests which may not be built because of EXCLUDE_FROM_ALL and will
+    # therefore fail. They can be ignored by adding them to CTestCustom.cmake
+    # See https://gitlab.kitware.com/cmake/cmake/-/issues/20212
+    include(LocalFuzztest)
+
     fuzztest_setup_fuzzing_flags()
 
     # Create a library with avif_fuzztest_helpers.cc to compile it only once.
@@ -220,7 +213,7 @@ if(AVIF_ENABLE_FUZZTEST)
     add_avif_fuzztest(avif_fuzztest_read_image)
     add_avif_fuzztest(avif_fuzztest_yuvrgb)
 else()
-    message(STATUS "FuzzTest targets are disabled because AVIF_ENABLE_FUZZTEST is OFF.")
+    message(STATUS "FuzzTest targets are disabled because AVIF_LOCAL_FUZZTEST is OFF.")
 endif()
 
 ################################################################################

tests/CTestCustom.cmake

@@ -1,4 +1,4 @@
 set(CTEST_CUSTOM_TESTS_IGNORE
-    # Ignore failing tests brought by `add_subdirectory(${AVIF_SOURCE_DIR}/ext/fuzztest)` when AVIF_ENABLE_FUZZTEST is ON
+    # Ignore failing tests brought by `add_subdirectory(${AVIF_SOURCE_DIR}/ext/fuzztest)` when AVIF_LOCAL_FUZZTEST is ON
     antlr4_tests_NOT_BUILT
 )

tests/oss-fuzz/README.md

@@ -7,7 +7,7 @@ This document provides links and knowledge about fuzzing libavif on oss-fuzz.
 You need to build with the following CMake flags:
 
 ```sh
--DAVIF_CODEC_AOM=LOCAL -DAVIF_CODEC_AOM_DECODE=ON -DAVIF_CODEC_AOM_ENCODE=ON -DAVIF_CODEC_DAV1D=LOCAL -DAVIF_LIBYUV=LOCAL -DAVIF_LIBSHARPYUV=LOCAL -DAVIF_BUILD_TESTS=ON -DAVIF_ENABLE_GTEST=ON -DAVIF_GTEST=LOCAL -DAVIF_LOCAL_FUZZTEST=ON -DAVIF_ENABLE_FUZZTEST=ON -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DAVIF_ENABLE_WERROR=OFF
+-DAVIF_CODEC_AOM=LOCAL -DAVIF_CODEC_AOM_DECODE=ON -DAVIF_CODEC_AOM_ENCODE=ON -DAVIF_CODEC_DAV1D=LOCAL -DAVIF_LIBYUV=LOCAL -DAVIF_LIBSHARPYUV=LOCAL -DAVIF_BUILD_TESTS=ON -DAVIF_ENABLE_GTEST=ON -DAVIF_GTEST=LOCAL -DAVIF_LOCAL_FUZZTEST=ON -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DAVIF_ENABLE_WERROR=OFF
 ```
 
 You can then run your tests as normal:

tests/oss-fuzz/build.sh

@@ -71,7 +71,7 @@ cd build
 EXTRA_CMAKE_FLAGS=""
 if [[ "$FUZZING_ENGINE" == "libfuzzer" ]]; then
   CXXFLAGS="${CXXFLAGS} -DFUZZTEST_COMPATIBILITY_MODE"
-  EXTRA_CMAKE_FLAGS="${EXTRA_CMAKE_FLAGS} -DAVIF_ENABLE_FUZZTEST=ON -DFUZZTEST_COMPATIBILITY_MODE=libfuzzer"
+  EXTRA_CMAKE_FLAGS="${EXTRA_CMAKE_FLAGS} -DFUZZTEST_COMPATIBILITY_MODE=libfuzzer"
 fi
 cmake .. -G Ninja -DBUILD_SHARED_LIBS=OFF -DAVIF_CODEC_AOM=LOCAL -DAVIF_CODEC_DAV1D=LOCAL \
       -DAVIF_CODEC_AOM_DECODE=ON -DAVIF_CODEC_AOM_ENCODE=ON \