what does the with-layout=gnu option do?

Question

I am compiling PHP 5.3.6 and the compile configure command I am using as a reference uses the --with-layout=GNU option. I have done some research but I can't seem to find a detail answer. Can someone please explain this option to me in detail and why one would use it? Thanks!

Answer 1

In the latest version of PHP's configure.in at the time of this answer, --with-layout is defined as:

PHP_ARG_WITH(layout, layout of installed files,
[  --with-layout=TYPE      Set how installed files will be laid out.  Type can
                          be either PHP or GNU [PHP]], PHP, no)

case $PHP_LAYOUT in
  GNU)
    oldstyleextdir=no
    ;;
  *)
    oldstyleextdir=yes
    ;;
esac

So if you choose GNU, it sets oldstyleextdir=no, otherwise yes. That helped me to find this mail to php-dev in Dec 2005, which says in part:

With that said, old style is:

$libdir/extensions/$extbasedir

while new style [GNU] is:

$libdir/$extbasedir

Essentially, this option decides the location of the extensions directory (EXTENSION_DIR). Unfortunately, as the author of that mail notes, there isn't a lot of explanation about why the option was implemented – even in the commit log entry – though I speculate it was to keep PHP in line with other "GNU/Linux" standards.