A preprocessor "trick" not mentioned in the article is the use of GNU statement expressions.

The article describes the do {} while(0) trick to make macros look like statements. They can then basically be used like inline void function calls. But what if you want to write a macro to replace an inline function that returns a result?

Statement expressions [1] solve that problem. Now you can finally do this:

    int _foo(int x) { return 2 * x; }

    #ifdef __DEBUG__
    #   define foo(x) \({                     \
            int r = _foo(x);                  \
            printf(                           \
                "foo returned: %d (%s:%d)\n", \
                r, __FILE__, __LINE__         \
            );                                \
            r;                                \
        })
    #else
    #   define foo _foo
    #endif

They are supported by most popular compilers which are not made by Microsoft (including GCC and clang).

[1] https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html