[gentoo-alt] readline->libncursesw.so?

[Gregory M. Turner]

This is pretty much off-topic, but:

o It's kind-of off-topic everywhere
o I've only tested this on prefix
o I've posted too many low-content posts on -dev lately :)

The "inspiration" for this comes from the readline cygport.  I had a 
similar patch in my overlay tree, where, frankly, I tend to slavishly 
imitate cygports, at least until I manage to understand it and can 
intelligently gentoo-ize their changes.

Anyhow, it occurred to me that there might be nothing cygwin-specific 
about this particular patch, so I tested it on an x86-linux overlay and 
"it works" (so far).  If there's any interest I could test more 
environments.

I guess I should say what I'm talking about.  The following patches the 
readline ebuild so that libreadline will depend on libncursesw instead 
of libncurses (if and only if the unicode use-flag is enabled).  From 
what I can glean from the interweb, some distros do this and some don't. 
  As for what the actual advantages or disadvantages might be,
I really have no clue.

I have heard some buzz that loading ncurses and ncursesw into the same 
process space can cause problems, so there is, purportedly, at least, 
some potential for this to trigger a reverse-dependency cascade forcing 
ncursesw down the throat of a bunch of different ebuilds (if the unicode 
use-flag is set)

Whether that's a bad or a good thing is open for debate.

I'm skeptical, insofar as it fixes something that doesn't seem broken, 
but thought I should document, somewhere, that it "works for me," and 
see if maybe someone who knows and/or cares more about this than I has 
any input.

diff -u a/sys-libs/readline/readline-6.2_p1-r1.ebuild 
b/sys-libs/readline/readline-6.2_p1-r1.ebuild
--- a/sys-libs/readline/readline-6.2_p1-r1.ebuild       2012-05-26 
07:44:24.000000000 -0700
+++ b/sys-libs/readline/readline-6.2_p1-r1.ebuild   2012-08-17 
16:12:39.704843218 -0700
@@ -2,6 +2,7 @@
  # Distributed under the terms of the GNU General Public License v2
  # $Header: 
/var/cvsroot/gentoo-x86/sys-libs/readline/readline-6.2_p1-r1.ebuild,v 
1.4 2012/04/30 01:36:43 vapier Exp $

+EAPI=2
  inherit eutils multilib toolchain-funcs flag-o-matic

  # Official patches
@@ -33,9 +34,9 @@
  LICENSE="GPL-3"
  SLOT="0"
  KEYWORDS="~ppc-aix ~x64-freebsd ~x86-freebsd ~hppa-hpux ~ia64-hpux 
~x86-interix ~amd64-linux ~ia64-linux ~x86-linux ~ppc-macos ~x64-macos 
~x86-macos ~m68k-mint ~sparc-solaris ~sparc64-solaris ~x64-solaris 
~x86-solaris"
-IUSE="static-libs"
+IUSE="static-libs unicode"

-RDEPEND=">=sys-libs/ncurses-5.2-r2"
+RDEPEND=">=sys-libs/ncurses-5.2-r2[unicode=]"
  DEPEND="${RDEPEND}"

  S=${WORKDIR}/${MY_P}
@@ -45,6 +46,9 @@

         cd "${S}"
         [[ ${PLEVEL} -gt 0 ]] && epatch $(patches -s)
+}
+
+src_prepare() {

         epatch "${FILESDIR}"/${PN}-5.0-no_rpath.patch
         epatch "${FILESDIR}"/${PN}-5.2-no-ignore-shlib-errors.patch #216952
@@ -60,8 +64,11 @@
         epatch "${FILESDIR}"/${PN}-6.1-aix-expfull.patch
         epatch "${FILESDIR}"/${PN}-6.1-aix-soname.patch

+       ncursesw=
+       use unicode && ncursesw=w
+
         # force ncurses linking #71420
-       sed -i -e 's:^SHLIB_LIBS=:SHLIB_LIBS=-lncurses:' 
support/shobj-conf || die "sed"
+       sed -i -e "s:^SHLIB_LIBS=:SHLIB_LIBS=-lncurses${ncursesw}:" 
support/shobj-conf || die "sed"

         # fix building under Gentoo/FreeBSD; upstream FreeBSD deprecated
         # objformat for years, so we don't want to rely on that.
@@ -73,12 +80,14 @@
         ln -s ../.. examples/rlfe/readline # for local readline headers
  }

-src_compile() {
+src_configure() {
         # fix implicit decls with widechar funcs
         append-cppflags -D_GNU_SOURCE
         # 
http://lists.gnu.org/archive/html/bug-readline/2010-07/msg00013.html
         append-cppflags -Dxrealloc=_rl_realloc -Dxmalloc=_rl_malloc 
-Dxfree=_rl_free

+       use unicode && append-cppflags -I/usr/include/ncursesw
+
         # This is for rlfe, but we need to make sure LDFLAGS doesn't change
         # so we can re-use the config cache file between the two.
         append-ldflags -L.
@@ -86,6 +95,15 @@
                 --cache-file="${S}"/config.cache \
                 --with-curses \
                 $(use_enable static-libs static)
+       if ! tc-is-cross-compiler ; then
+               # code is full of AC_TRY_RUN()
+               cd examples/rlfe
+               econf --cache-file="${S}"/config.cache
+       fi
+}
+
+src_compile() {
+       cd "${S}"
         emake || die

         if ! tc-is-cross-compiler ; then
@@ -96,7 +114,6 @@
                         ln -s ../../shlib/lib${l}*$(get_libname)* 
lib${l}$(get_libname)
                         ln -sf ../../lib${l}.a lib${l}.a
                 done
-               econf --cache-file="${S}"/config.cache
                 emake || die
         fi
  }
------------------------
-gmt