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pauldreiklemire
pauldreik
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lemire
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add basic fuzzers (simdjson#348)
* add basic fuzzing using libFuzzer * let cmake respect cflags, otherwise the fuzzer flags go unnoticed also, integrates badly with oss-fuzz * add new fuzzer for minification, simplify the old one * add fuzzer for the dump example * clang format
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6 files changed

Lines changed: 134 additions & 2 deletions

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‎CMakeLists.txt‎

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@@ -48,6 +48,12 @@ add_subdirectory(tools)
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add_subdirectory(tests)
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add_subdirectory(benchmark)
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# for fuzzing, read the comments in the fuzz/CMakeLists.txt file
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option(ENABLE_FUZZING "enable fuzzing (experimental, requires clang)" OFF)
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if(ENABLE_FUZZING)
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add_subdirectory(fuzz)
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endif()
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set(CPACK_PACKAGE_VENDOR "Daniel Lemire")
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set(CPACK_PACKAGE_CONTACT "lemire@gmail.com")
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set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "Parsing gigabytes of JSON per second")
@@ -62,3 +68,5 @@ set(CPACK_RPM_PACKAGE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/LICENSE")
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set(CPACK_SOURCE_GENERATOR "TGZ;ZIP")
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include(CPack)
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‎fuzz/CMakeLists.txt‎

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# First attempt at a fuzzer, using libFuzzer.
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#
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# compile like this:
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# mkdir build-fuzzer
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# cd build-fuzzer
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# export LDFLAGS="-fsanitize=address,undefined"
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# export CXXFLAGS="-fsanitize=fuzzer-no-link,address,undefined"
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# export CFLAGS="-fsanitize=fuzzer-no-link,address,undefined"
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# export CXX=clang++
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# export CC=clang++
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# cmake .. -GNinja -DCMAKE_BUILD_TYPE=Debug -DENABLE_FUZZING=On
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# ninja
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if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
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add_executable(fuzz_parser fuzz_parser.cpp)
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target_link_libraries(fuzz_parser PRIVATE ${SIMDJSON_LIB_NAME} )
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target_link_libraries(fuzz_parser PRIVATE "-fsanitize=fuzzer")
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add_executable(fuzz_minify fuzz_minify.cpp)
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target_link_libraries(fuzz_minify PRIVATE ${SIMDJSON_LIB_NAME} )
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target_link_libraries(fuzz_minify PRIVATE "-fsanitize=fuzzer")
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add_executable(fuzz_dump fuzz_dump.cpp)
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target_link_libraries(fuzz_dump PRIVATE ${SIMDJSON_LIB_NAME} )
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target_link_libraries(fuzz_dump PRIVATE "-fsanitize=fuzzer")
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endif()
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‎fuzz/fuzz_dump.cpp‎

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#include "simdjson/jsonparser.h"
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#include <cstddef>
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#include <cstdint>
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#include <iostream>
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#include <string>
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// from https://stackoverflow.com/a/8244052
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class NulStreambuf : public std::streambuf {
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char dummyBuffer[64];
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protected:
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virtual int overflow(int c) {
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setp(dummyBuffer, dummyBuffer + sizeof(dummyBuffer));
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return (c == traits_type::eof()) ? '\0' : c;
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}
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};
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class NulOStream : private NulStreambuf, public std::ostream {
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public:
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NulOStream() : std::ostream(this) {}
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NulStreambuf *rdbuf() { return this; }
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};
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// from the README on the front page
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void compute_dump(simdjson::ParsedJson::Iterator &pjh) {
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NulOStream os;
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if (pjh.is_object()) {
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os << "{";
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if (pjh.down()) {
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pjh.print(os); // must be a string
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os << ":";
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pjh.next();
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compute_dump(pjh); // let us recurse
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while (pjh.next()) {
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os << ",";
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pjh.print(os);
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os << ":";
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pjh.next();
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compute_dump(pjh); // let us recurse
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}
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pjh.up();
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}
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os << "}";
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} else if (pjh.is_array()) {
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os << "[";
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if (pjh.down()) {
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compute_dump(pjh); // let us recurse
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while (pjh.next()) {
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os << ",";
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compute_dump(pjh); // let us recurse
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}
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pjh.up();
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}
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os << "]";
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} else {
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pjh.print(os); // just print the lone value
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}
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}
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
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try {
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auto pj = simdjson::build_parsed_json(Data, Size);
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simdjson::ParsedJson::Iterator pjh(pj);
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if (pjh.is_ok()) {
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compute_dump(pjh);
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}
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} catch (...) {
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}
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return 0;
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}

‎fuzz/fuzz_minify.cpp‎

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#include "simdjson/jsonminifier.h"
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#include "simdjson/jsonparser.h"
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#include <cstddef>
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#include <cstdint>
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#include <string>
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
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auto begin = (const char *)Data;
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auto end = begin + Size;
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std::string str(begin, end);
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simdjson::json_minify(str.data(), str.size(), str.data());
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return 0;
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}

‎fuzz/fuzz_parser.cpp‎

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#include "simdjson/jsonparser.h"
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#include <cstddef>
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#include <cstdint>
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#include <string>
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
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auto ignored = simdjson::build_parsed_json(Data, Size);
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return 0;
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}

‎tools/cmake/FindOptions.cmake‎

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@@ -46,13 +46,13 @@ set(CMAKE_C_FLAGS_DEBUG "-ggdb")
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set(CMAKE_C_FLAGS_RELEASE "-O3")
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endif()
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set(CMAKE_C_FLAGS "${STD_FLAGS} ${OPT_FLAGS} ${INCLUDE_FLAGS} ${WARNING_FLAGS} ${SIMDJSON_SANITIZE_FLAGS} ")
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set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${STD_FLAGS} ${OPT_FLAGS} ${INCLUDE_FLAGS} ${WARNING_FLAGS} ${SIMDJSON_SANITIZE_FLAGS} ")
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if(NOT MSVC)
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set(CMAKE_CXX_FLAGS_DEBUG "-ggdb")
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set(CMAKE_CXX_FLAGS_RELEASE "-O3")
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endif()
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set(CMAKE_CXX_FLAGS "${CXXSTD_FLAGS} ${OPT_FLAGS} ${INCLUDE_FLAGS} ${WARNING_FLAGS} ${SIMDJSON_SANITIZE_FLAGS} ")
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set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CXXSTD_FLAGS} ${OPT_FLAGS} ${INCLUDE_FLAGS} ${WARNING_FLAGS} ${SIMDJSON_SANITIZE_FLAGS} ")
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if(MSVC)
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add_definitions( "${OPT_FLAGS} /W3 /D_CRT_SECURE_NO_WARNINGS /wd4005 /wd4996 /wd4267 /wd4244 /wd4113 /nologo")

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