if with no code block parenthesis

Whatever, I agree with you, it would be worse in C / C++ code using macros.
Suppose you got a multiline macro like this:

#define some_macro \
    do_something_1(); \
    do_something_2();

And using this macro without parenthesis:

if(...)
    some_macro;

or

for(...)
    some_macro;

Only do_something_1() will be executed internally in those if / for blocks and do_something_2() is treated as an external statement.
So I'm used to add a pair of { } there, and even surround multiline macros with them in C / C++ like:

#define some_macro \
    { \
        do_something_1(); \
        do_something_2(); \
    }

That would be better I think.