C Preprocessor val##LL

[cybernerdsx2]

hi all,

I am not sure if this is the right group to post this question but I
don't want to cross post this message over to other groups as well. So
that's why I choose the closest match to post this question.

Okay, I was looking at the Apache HTTP Server source code and found an
interesting type as following:

#define APR_TIME_C(val) APR_INT64_C(val)

Can anyone tell me is the "val" a C compiler preprocessor?


Rgds,

FJ

 

[Keith Thompson]

I am not sure if this is the right group to post this question but I
don't want to cross post this message over to other groups as well. So
that's why I choose the closest match to post this question.

Okay, I was looking at the Apache HTTP Server source code and found an
interesting type as following:

#define APR_TIME_C(val) APR_INT64_C(val)

Can anyone tell me is the "val" a C compiler preprocessor?

'val' is simply the name of the macro parameter. It could just as
easily have been 'x', or 'arg', or 'foobar'. The definition means
that any occurrence of
APR_TIME_C(42)
will be replaced by
APR_INT64_C(42)
and likewise for any other argument. (Probably APR_INT64_C is another
macro.)

Any decent C textbook should explain this.

If that doesn't answer your question, please rephrase it; the question
you asked doesn't really make any sense. Probably you just left out a
word, but I can't guess what it was.