tidy - cppcoreguidelines-macro-usage — Extra Clang Tools 22.0.0git documentation (original) (raw)

Finds macro usage that is considered problematic because better language constructs exist for the task.

The relevant sections in the C++ Core Guidelines areES.31, andES.32.

Examples:

#define C 0 #define F1(x, y) ((a) > (b) ? (a) : (b)) #define F2(...) (VA_ARGS) #define F3(x, y) x##y #define COMMA , #define NORETURN [[noreturn]] #define DEPRECATED attribute((deprecated)) #if LIB_EXPORTS #define DLLEXPORTS __declspec(dllexport) #else #define DLLEXPORTS __declspec(dllimport) #endif

results in the following warnings:

4 warnings generated. test.cpp:1:9: warning: macro 'C' used to declare a constant; consider using a 'constexpr' constant [cppcoreguidelines-macro-usage] #define C 0 ^ test.cpp:2:9: warning: function-like macro 'F1' used; consider a 'constexpr' template function [cppcoreguidelines-macro-usage] #define F1(x, y) ((a) > (b) ? (a) : (b)) ^ test.cpp:3:9: warning: variadic macro 'F2' used; consider using a 'constexpr' variadic template function [cppcoreguidelines-macro-usage] #define F2(...) (VA_ARGS) ^

Options¶

AllowedRegexp¶

A regular expression to filter allowed macros. For exampleDEBUG*|LIBTORRENT*|TORRENT*|UNI* could be applied to filter libtorrent. Default value is ^DEBUG_*.

CheckCapsOnly¶

Boolean flag to warn on all macros except those with CAPS_ONLY names. This option is intended to ease introduction of this check into older code bases. Default value is false.

IgnoreCommandLineMacros¶

Boolean flag to toggle ignoring command-line-defined macros. Default value is true.