Intro

A clang-tidy plugin for personal checks. These checks are too optionated such that not suitable to be contributed to clang-tidy.

NOTE:

The plugin must be used with clang-tidy and cannot be used along. And I assume you already knows how to use clang-tidy.

Usage

Build

MacOS + Local LLVM

# Configuration
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DLOCAL_CLANG=$(brew --prefix llvm@17)

# Build
cmake --build build -j

You will get a libcppsafe-tidy.so file after build, put it somewhere.

Test

cd tests
bash run-tests.sh

Use

Make sure clang-tidy is installed.

clang-tidy --checks='cppsafe*' --load xxxx/libcppsafe-tidy.so your-code.cpp

Checks

cppsafe-unused-return-value

The opposite of bugprone-unused-return-value. Code is almost copied from it.

Check all return values by default with the following exceptions:

• functions
  • ::sleep
  • ::usleep
  • memcpy
  • memset
  • memmove
  • printf
  • fprintf
  • sprintf
  • snprintf
  • strcpy
  • strncpy
  • signal
  • fputs
  • ::std::copy
  • ::std::copy_if
  • ::std::copy_n
  • ::std::copy_backward
  • ::std::transform
  • erase
  • erase_if
  • emplace_back
  • fetch_add
  • fetch_sub
  • ::fmt::format_to
• functions returns T&
• functions named insert and emplace but returns an iterator
• member functions of std::atomic

You can mark a function as [[clang::annotate("cppsafe::may_discard")]] to ignore its return values.

struct FileHandle
{
    int Open();
    [[clang::annotate("cppsafe::may_discard")]] int Close();
};

FileHandle f;
f.Open();  // warning
f.Close();  // no warning

There are also options to ignore it.

• IgnoredFunctions: ; separated names
• IgnoreFunctionRegex: a regex, functions matched are ignored
• AllowCastToVoid: default true