bug#3441: 23.0.94; *compilation* long lines painfully slow

[joakim]

Chong Yidong <cyd@stupidchicken.com> writes:

>> Create a Makefile with the contents:
>>
>> all:
>>      @echo [insert 5000 chars]
>>
>> Run emacs -Q and do Tools > Compile... RET and I see Emacs create the
>> *compilation* window and insert chunks of the echo output.  23.0.94
>> takes 20+ seconds to complete it and is pretty much unusable during that
>> time.  22.3 takes 1 second.  Looking back at earlier pretests, this also
>> applies to 23.0.91.
>
> This is due to the following in compilation-error-regexp-alist-alist:
>
>   (maven
>    ;; Maven is a popular build tool for Java.  Maven is Free Software.
>    "\\(.*?\\):\\[\\([0-9]+\\),\\([0-9]+\\)\\]" 1 2 3)
>
> which was added here:
>
> 2007-07-25  Joakim Verona  <joakim@verona.se>  (tiny change)
>
>       * progmodes/compile.el (compilation-error-regexp-alist-alist):
>       Add support for the Maden build tool.
>
> This regexp is pathologically slow on long lines.  Since the performance
> impact is quite serious, and this bug has affected more than one user, I
> went ahead and commented out this line in compile.el.
>
> Joakim, could try to come up with a faster regexp?

Ok, I will give it a shot.

-- 
Joakim Verona