Re: Following renames

[Jakub Narebski <jnareb@gmail.com>]

Linus Torvalds wrote:

> On Sun, 26 Mar 2006, Jakub Narebski wrote:
>>
>> I wonder what is the most common case in Linux kernel or git.
>> 
>> 1.) renaming the file in the same directory, old-file.c to new-file.c?
>> 2.) moving file to other directory (project reorganization), 
>>     old-dir/file.c to new-dir/file.c?
> The kernel uses subdirectories extensively, and a lot of renames (most of
> them, I'd say) is because of that subdirectory structure.
> 
> So the same-directory case is the unusual one, I'd say.

If (2) is common enough then discussed improvements to rename detection, 
namely comparing basenames as a base for candidate selection is a good idea.
I wonder how common is (2) compared to (1)+(2) i.e. move to other dir 
and rename, old-dir/old-file.c to new-dir/new-subdir/new-file.c

>> 3.) splitting file into modules, huge-file.c to file1.c, file2.c?
>> 4.) copying fragment of one file to other?
>> 5.) moving fragment of code from one file to other?
> 
> I'd say that (5) is very common. And (4) happens a lot under certain
> circumstances (new driver, new architecture, new filesystem..).
> 
> Doing (3) happens, but probably less often that it should ;/

Detecting (4) and (5) fast (i.e. for merges) without auxilary (helper) 
information would probably be hard. For interrogation/porcellanish commands
(like pickaxe) would probably be easier.

-- 
Jakub Narebski
Warsaw, Poland