[clang-tidy] Check request: bugprone-avoid-inline-constexpr-in-implementations

[denzor200]

C++17 suggests us the possibility to use inline on constexpr variables, but when identical inline constexpr variables are defined in different translation units with different values, this violates the One Definition Rule (ODR) which manifests unpredictably (e.g., different values in different TUs).
Need a check to get rid from inline keyword on constexpr variables in source files.

BEFORE:

// foo.cpp
inline constexpr int MAX_SIZE = 1024;

AFTER:

// foo.cpp
constexpr int MAX_SIZE = 1024;

Scope

• Applies only to sources (.cpp, .cxx, etc.), ignoring .h files.

Why bugprone-?

• Runtime behaviour potentially affected due to unexpected constant's value selected in link time.

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Denis Mikhailov (denzor200)

C++17 suggests us the possibility to use `inline` on `constexpr` variables, but when identical `inline constexpr` variables are defined in different translation units with different values, this violates the One Definition Rule (ODR) which manifests unpredictably (e.g., different values in different TUs). Need a check to get rid from `inline` keyword on `constexpr` variables in source files.

BEFORE:

// foo.cpp
inline constexpr int MAX_SIZE = 1024;

AFTER:

// foo.cpp
constexpr int MAX_SIZE = 1024;

Scope

• Applies only to sources (.cpp, .cxx, etc.), ignoring .h files.

Why bugprone-?

• Runtime behaviour potentially affected due to unexpected constant's value selected in link time.

[denzor200]

@vbvictor could you please add C++17 label here? Since the bug described in this issue only possible to reproduce with C++17 and newer

[llvmbot]

@llvm/issue-subscribers-c-17

Author: Denis Mikhailov (denzor200)

C++17 suggests us the possibility to use `inline` on `constexpr` variables, but when identical `inline constexpr` variables are defined in different translation units with different values, this violates the One Definition Rule (ODR) which manifests unpredictably (e.g., different values in different TUs). Need a check to get rid from `inline` keyword on `constexpr` variables in source files.

BEFORE:

// foo.cpp
inline constexpr int MAX_SIZE = 1024;

AFTER:

// foo.cpp
constexpr int MAX_SIZE = 1024;

Scope

• Applies only to sources (.cpp, .cxx, etc.), ignoring .h files.

Why bugprone-?

• Runtime behaviour potentially affected due to unexpected constant's value selected in link time.