Clang Flag: -Wc++14-extensions / -Wno-c++14-extensions

The Clang compiler flags -Wc++14-extensions and -Wno-c++14-extensions are used to control warnings related to C++14 language extensions. When compiling C++ code, developers might encounter language features that are specific to C++14. These flags offer a mechanism to either enable or suppress warnings for these features, aiding developers in maintaining compatibility with the C++14 standard. The -Wc++14-extensions flag, when explicitly enabled, activates warnings for certain C++14 extensions that are not activated by default. This flag is useful for developers who aim to write portable code that adheres strictly to the C++14 standard without utilizing certain extensions that Clang allows by default. Currently, this includes features like binary integer literals and the use of certain C++14-specific attributes. Conversely, the -Wno-c++14-extensions flag deactivates warnings for a broader range of C++14 extensions that are activated by default. This is beneficial for developers who are leveraging C++14 extensions knowingly and wish to suppress related warnings to focus on more relevant issues within their codebase. The default active warnings encompass features such as multiple return statements in constexpr functions, variable templates, and initialized lambda captures among others. By deactivating these warnings, developers can write code that takes full advantage of C++14 extensions without being encumbered by compiler warnings for doing so. Both flags serve distinct purposes with -Wc++14-extensions being geared towards enforcing strict adherence to the C++14 standard by highlighting extensions, while -Wno-c++14-extensions allows developers the freedom to use C++14 specific features without compiler interference. These flags are part of the broader ecosystem of compiler options that assist in writing, debugging, and optimizing C++ code.

AI Generated

Supergroups

• -Wc++1y-extensions (9 elements)

Subroups

• -Wc++14-binary-literal (1 element)
• -Wc++14-attribute-extensions (1 element)

Warnings/Remarks

Default Active (Deactivate with -Wno-c++14-extensions)

ext_constexpr_body_invalid_stmt	warning: use of this statement in a constexpr function constructor is a C++14 extension
ext_constexpr_body_multiple_return	warning: multiple return statements in constexpr function is a C++14 extension
ext_constexpr_local_var	warning: variable declaration in a constexpr function constructor is a C++14 extension
ext_constexpr_type_definition	warning: type definition in a constexpr function constructor is a C++14 extension
ext_decltype_auto_type_specifier	warning: 'decltype(auto)' type specifier is a C++14 extension
ext_init_capture	warning: initialized lambda captures are a C++14 extension
ext_variable_template	warning: variable templates are a C++14 extension

Default Inactive (Activate with -Wc++14-extensions)

ext_binary_literal_cxx14	warning: binary integer literals are a C++14 extension
ext_cxx14_attr	warning: use of the A attribute is a C++14 extension