On 16/10/2022 20.28, Ramon Fried wrote:
On Fri, Oct 14, 2022 at 8:44 PM Rasmus Villemoes rasmus.villemoes@prevas.dk wrote:
Nothing inside this block depends on NET_TFTP_VARS to be set to parse correctly. Switch to C if() in preparation for adding code before this (to avoid a declaration-after-statement warning).
What's the motivation here ? The #ifdef is supposed to allow smaller code size if feature is not used.
And as always with these types of conversions, nothing changes in that regard - an "if (0)" is optimized out by the compiler just fine.
The motivation is in the commit message: The following patch will need to add a bit of logic at the very beginning of the function, so if I left the #ifdef block as-is, the declaration of the ep variable would lead to a declaration-after-statement warning; lifting the declaration to the top would either require repeating the ugly ifdeffery, or give a "variable not used" warning.
It's also in general the preferred method, because it means the contained code gets checked for syntactic correctness regardless of .config - but that very same thing is also why it cannot be applied universally, if the contained code e.g. refers to struct fields that are only defined with certain CONFIG_FOO set [and this also was alluded to in the commit message].
Rasmus