[swift-evolution] [Pitch] Introducing #fileName debug identifier

[Dmitri Gribenko]

On Sat, Mar 12, 2016 at 7:04 PM, Erica Sadun via swift-evolution
<swift-evolution at swift.org> wrote:
> Here is a small one as pitches go, but I think it embraces the spirit of the
> Groff (http://bit.ly/1pn47Yr).
>
> Of all the possible expansions brought up in the SE-0028  discussion on
> modernizing
> debug identifiers, I would get a lot of use out of `#fileName`  for my debug
> logging.
> A simple websearch for `__FILE__ lastPathComponent` yields page after page
> of results
> across both Swift and Objective-C.
>
> My idea is that a `#fileName` debug identifier would return the file name
> and not the entire
> path for logging.

It should be OK to have multiple files with the same name in the
project.  For example, in the Swift compiler we have Decl.cpp in both
Clang and Swift.  It is important to distinguish these in the
assertion messages.

Thus, I'd suggest to consider instead passing the project directory to
the compiler, so that the compiler can provide a file name relative to
the project root.

You can even go as far as replacing the project root with the
project-version string.  For example:

#relativeFileName could expand to
"<MyStringExtras-1.0>/String+KnuthMorrisPrattSearch.swift"

Dmitri

-- 
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/