cppcoreguidelines-macro-usage¶
Finds macro usage that is considered problematic because better language constructs exist for the task.
The relevant sections in the C++ Core Guidelines are ES.31, and ES.32.
Examples:
#define C 0
#define F1(x, y) ((a) > (b) ? (a) : (b))
#define F2(...) (__VA_ARGS__)
#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 example DEBUG*|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.