'assert' is not a keyword. Even if it were, they overrode it with a function that has the exact same signature and general runtime behaviour. Hardly anything to be surprised about.
Also, invoking the principle of least surprise on a C codebase is just ludicrous.
I didn't say it was a keyword. It's a standard function-like macro (not a function, as I wrote).
I would think it just as bad an idea to overload `NULL` with something non-standard.
The standard things in the language are something to be learned, and they should remain constant and not change per-project just because someone can do it differently. Do it however you like, but don't clobber the standard names, is all I'm saying.
The "principle of least surprise" would say that of course asserts are turned off with -NDEBUG. From assert(3) on osx:
"""The assert() macro may be removed at compile time with the cc(1) option -DNDEBUG."""
In general I would agree with you—it sucks to override a standard function with weird, local, non-standard functionality. However, in this case, it's an extremely common practice to override assert() so that it only aborts or warns during testing or when some DEBUG macro is defined. To attack that is to ignore long-standing, wide-spread idioms.
I believe it violates the principle of least surprise, which I generally would consider a good principle.
As a new reader of the code, you'd be quite sane to expect "assert" to mean assert(), not "our local assert(), which is something different".
There should be a --disallow-keyword-redefinitions flag to the preprocessor, or something. Grumble.