https://gcc.gnu.org/onlinedocs/cpp/Macros.html#Macros

• Object-like Macros

• Function-like Macros

• Macro Arguments

• Stringification

• Concatenation

• Variadic Macros

• Predefined Macros

• Undefining and Redefining Macros

• Directives Within Macro Arguments

• Macro Pitfalls

C语言宏怎么玩儿得更好？