There is no reason for them to be all-uppercase. I hate it when people use uppercase for functions, including macro functions. All-uppercase is a convention for symbolic constants, not functions.
It seems that we've decided sometime back that all macro-fns should be declared in ucase. Now, we can debate that issue again, but if someone could pull up a reference to that thread in the archives it would be most cool.
I'm pro-ucase only in one situation, in general I'm agnostic. The macro arg that is used twice or more within the macro body becomes some serious buggy garbage. MACRO_FN(foo++) is a much easier bug to notice than macro_fn(foo++). Only one of these macros in my experimental binary usec implementation will actually trigger this;
+#define APR_TIME_FROM_USEC(usec) ((((apr_time_t)(usec) / APR_TIME_C(1000000)) \
+ * APR_BUSEC_PER_SEC) \
+ + (((apr_time_t)(usec) % APR_TIME_C(1000000)) \
+ * APR_BUSEC_PER_SEC) \
+ / APR_TIME_C(1000000))
Where we must split the math to avoid serious underflow conditions, with a loss of precision down to 2^21 for seconds (less than 25 days!!!) Although I don't see where we will convert usec time to binary usec time very often (most inputs will be in seconds + usec, on Win32 it's sec + 100ns units) this is just a good example of how a macro arg can break coders assumptions.
