reason for both --libdir and --libsubdir ?

[Duncan Coutts]

On Wed, 2007-08-08 at 12:06 +0100, Duncan Coutts wrote:
> On Wed, 2007-08-08 at 09:22 +0100, Simon Marlow wrote:
> > Duncan Coutts wrote:
> > > I am trying to understand the reason we have so many --dir flags to
> > > configure. I'd prefer to remove what appear to be duplicates and add
> > > some more dir overrides for specific file types (like docs).
> > > 
> > > We currently have:
> > > 
> > > --libdir= and --libsubdir=
> > > --datadir= and --datasubdir=
> 
> > Hmm, I remember going through several iterations of the design here before 
> > ending up with --libsubdir.  I can't remember all the rationale now (darn, 
> > wish I'd written it down somehwere).  Did you check the mailing list archives?
> 
> Yes, looking back at some patch descriptions and the thread on the
> libraries list from Oct 2005 titled: "Cabal: bindir/libdir/datadir" the
> rationale becomes clearer.
> 
> So the split between dir and subdir is for compatibility with autoconf,
> that is it allows users to say just --libdir=/usr/lib64 like they would
> with autoconf and end up with /usr/lib64/$pkgid/$compiler.

Just for reference here's autoconf's full list (it's big):


  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                          [PREFIX]

  --bindir=DIR           user executables [EPREFIX/bin]
  --sbindir=DIR          system admin executables [EPREFIX/sbin]
  --libexecdir=DIR       program executables [EPREFIX/libexec]
  --sysconfdir=DIR       read-only single-machine data [PREFIX/etc]
  --sharedstatedir=DIR   modifiable architecture-independent data [PREFIX/com]
  --localstatedir=DIR    modifiable single-machine data [PREFIX/var]
  --libdir=DIR           object code libraries [EPREFIX/lib]
  --includedir=DIR       C header files [PREFIX/include]
  --oldincludedir=DIR    C header files for non-gcc [/usr/include]
  --datarootdir=DIR      read-only arch.-independent data root [PREFIX/share]
  --datadir=DIR          read-only architecture-independent data [DATAROOTDIR]
  --infodir=DIR          info documentation [DATAROOTDIR/info]
  --localedir=DIR        locale-dependent data [DATAROOTDIR/locale]
  --mandir=DIR           man documentation [DATAROOTDIR/man]
  --docdir=DIR           documentation root [DATAROOTDIR/doc/gtk2hs]
  --htmldir=DIR          html documentation [DOCDIR]
  --dvidir=DIR           dvi documentation [DOCDIR]
  --pdfdir=DIR           pdf documentation [DOCDIR]
  --psdir=DIR            ps documentation [DOCDIR]

See also:
http://www.gnu.org/software/autoconf/manual/html_node/Installation-Directory-Variables.html#Installation-Directory-Variables
http://www.gnu.org/software/autoconf/manual/standards/Directory-Variables.html#Directory-Variables

They have some historical cruft we can ignore, like the --datarootdir
and --oldincludedir.

Note that the default autoconf docdir includes the package name.

Additionally, automake supports installing files into any of these with
an additional packagename subdir.