Tool ## KRISTEN SHAKER ## Agenda • Who Am I • Refactoring Tooling Use Cases • Clang Crash Course • Writing a Clang Tidy Check Live • Special Thanks & Questions ## 01 ## Who Am I ## C++ Core Libraries & other Bugs 03 ## Clang Tidies! ## What is a Clang Tidy  Existing Clang Tidies ## Existing Clang Tidies   ## Existing Clang Tidies

compiler and any version. There are default definitions for the most popular ones: gcc, cl.exe, clang, apple-clang, intel, with different configurations of versions, runtimes, C++ standard library, etc. This contain: Listing 1: clang_3.5 [settings] os=Macos arch=x86_64 compiler=clang compiler.version=3.5 compiler.libcxx=libstdc++11 build_type=Release [env] CC=/usr/bin/clang-3.5 CXX=/usr/bin/clang++-3.5 A profile file as a command line argument as shown in the example below: $ conan create . demo/testing -pr=clang_3.5 Continuing with the example of Poco, instead of passing in a long list of command line arguments

编译分享 程义 - 存储计算部 2022年11月11日 ## 更新内容 1 升级 bazel 到 4.2.2 2 支持 Debian9、Debian10、Debian11 3 支持 gcc clang ## 1 ## 编译 Debian11-Dockerfile .bazelrc bazel 版本：4.2.2 ( bazelisk) docker run -v $(pwd):/curve -config=gcc7-later ... # use '-faligned-new' to enable C++17 over-aligned new support # 使用 clang 编译 CC=clang CXX=clang++ bazel build ... ## 2 ## 制作镜像 docker run -v $(pwd):/curve -v /root/.cache/bazel:/root/ ian11 ## 3 ## 修改 & 单元测试 curvefs/test/tools/curvefs_version_tool_test.cpp # 使用 clang 编译 CC=clang CXX=clang++ bazel build curvefs/... ## THANK YOU 網易 NETEASE

VIRTUAL ## 2020 : The Year of Sanitizers? Victor Ciura Principal Engineer CAPHYON ## Abstract Clang-tidy is the go-to assistant for most C++ programmers looking to improve their code, whether to modernize smart tools, you have to try dynamic/runtime analysis. After years of improvements and successes for Clang and GCC users, LLVM AddressSanitizer (ASan) is finally available on Windows, in the latest Visual under active development 3.5 million lines of C++ code a few brave nerds... or “How we manage to clang-tidy our whole code base, while maintaining our monthly release cycle” https://www.youtube.com/watch

To use C++20 modules with CMake, you'll need to use a compiler that supports them, such as Clang 12 or later, or GCC 11 or later. You'll also need to specify the language standard and module B; export void b() {} ## Built Module Interface (BMI) MSVC - .ifc file • G++ - .gcm file • Clang - .pcm P1838R0: Modules User-Facing Lexicon and File Extensions ISO/IEC JTC1 SC22/WG21 - Programming Ben Boeckel ben.boeckel at kitware.com Fri Feb 8 16:55:20 CET 2019 • Previous message: [Tooling] Clang Modules and build system requirements • Next message: [Tooling] Fwd: [D1483] How CMake supports Fortran

code without user/business value ## Evolving styleguides ....with clang-format Improving with static analysis • Always provide a clang-format file - git-hooks to automatically apply formatting to changes 0_3.jpg) ## Static analysis and handling deprecations ...with clang-tidy • clang-tidy-diff lets you run only on changed lines - clang-compilation database may need modifications - replace PCH with namespace solutions • Different error handling strategies • Different code styles ### Please provide a .clang-format ## Dynamic library sharing ...with TestableDSP (TDSP) ![Image](/uploads/documents/9/2/4/5

c6/p27_1.jpg) ## Static analysis tools • Compiler errors and warnings ## • Lifetime safety • Clang experimental -Wlifetime ## Lifetime safety std::string get_string(); void dangling_string_view() (always_false()) foo(); } ## Data Flow Analysis ## CLion: • Local DFA since 1.x • Local DFA on Clang since 2020.1 Global (TU) DFA since 2021.1 • Lifetimes in 2021.2 ## PVS-Studio: • Value Range Analysis Analysis Data Flow Analysis: CTU ## Cross Translation Unit (CTU) Analysis: ##### https://clang.llvm.org/docs/analyzer/user-docs/CrossTranslationUnit.html CodeChecker https://github.com/Ericsson/ codechecker

sanitizers #include int main() { auto v = std::vector(16); return v[16]; } > clang -fsanitize=address main.cpp >=98481==ERROR: AddressSanitizer: heap-buffer-overflow on address ## Using RealtimeSanitizer (RTSan) float process(float x) [[clang::nonblocking]] { auto const y = std::vector(16); } > clang++ -fsanitize=realtime main.cpp ==86660==ERROR: RealtimeSanitizer: main+0x1c /app/example.cpp:12:5 ## Two steps 1. Attribute real-time functions with [[clang::nonblocking]] 2. Compile and link with -fsanitize=realtime ## How RealtimeSanitizer works RealtimeSanitizer

C++ CLING • RUNTIME COMPILED C++ / EASY-JIT • [[CLANG::JIT]] - P1609R1 ## EXISTING SOLUTIONS - C++ CLING • RUNTIME COMPILED C++ / EASY-JIT • [[CLANG::JIT]] - P1609R1 • D MIXIN** * WITH CUSTOM MODIFICATIONS EASY-JIT • [[CLANG::JIT]] - P1609R1 • D MIXIN** • OTHERS ## * WITH CUSTOM MODIFICATIONS ** COMPILE-TIME ## CLING ## [[CLANG::JIT]] ## CLING * PRIMARY A READ-EVAL-PRINT LOOP (REPL) ## [[CLANG::JIT]] ## (ATTRIBUTE) ## CLING ## * PRIMARY A READ-EVAL-PRINT LOOP (REPL) * ALWAYS JIT COMPILES THE WHOLE PROGRAM [[CLANG::JIT]] * C++ LANGUAGE EXTENSION (ATTRIBUTE) * ALLOWS JIT COMPILATION OF SPECIFICALLY-ANNOTATED FUNCTIONS

std::endl; } ## Or like that? x as Type; ## Available now! If you have C++20 compiler (GCC 10+, Clang 12+, MSVC 16.30+) ## FILIP SAJDAK Head of Engineering I am helping teams build HMI for premium cars Subsumption rules are not easy to grasp at first – CE gives fast feedbacks ## x is Type g++-10 Clang-12 MSVC v19.29 template constexpr auto is( X const& ) -> nullptr; } ## x is Type g++-10 Clang-12 MSVC v19.29 template< typename C, typename X> constexpr auto is( X const& ) -> std::false_type