Wireshark · Ethereal-dev: Re: [Ethereal-dev] README.developer - if (tree)

[Guy Harris <guy@xxxxxxxxxxxx>]

On Dec 16, 2003, at 2:12 PM, Devin Heitmueller wrote:

> How about this -- can we replace the function proto_tree_add_X() with a
> macro that checks to see if the first argument is non-null?

Yes, as long as "proto_tree_add_X" doesn't take a variable number of 
arguments.  (C89 doesn't support macros that take a variable number of 
arguments.)

Unfortunately, if "X" is "text" or includes the word "format", 
"proto_tree_add_X" *does* take a variable number of arguments.

> This would
> eliminate the need for the developer to add the "if (tree)" before 
> every
> call.  We would get the benefits of not having to do the stack loading,
> but also not have to clutter the code with the if statements.

If all you're doing is

	...

	if (tree)
		proto_XXX_add_YYY(...)

	...

rather than

	if (tree) {
		proto_XXX_add_YYY(...);
		proto_ZZZ_add_WWW(...);

			...
	}

then the only advantage of the "if (tree) is that you skip a procedure 
call.

The idea is to use "if (tree)" to surround a large *block* of code, so 
you can skip it all.