From e493be38440b6858b188a4467b6578aba87ffdfe Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@debian.org>
Date: Wed, 3 Jun 2020 11:03:35 +0100
Subject: [PATCH] scripts: Use special ${LIB} token for
 architecture-independence

On GNU/Linux systems, the literal string '${LIB}' in dynamic linker
paths expands to "lib", a biarch libQUAL directory such as "lib64", or
a Debian-style multiarch directory such as "lib/x86_64-linux-gnu".
If we're installing libraries to such a directory, and we have both
word-sizes' compatibility libraries available, then pw-pulse can
use LD_LIBRARY_PATH='/usr/${LIB}/pipewire-0.3/pulse' to make both
i386 and x86_64 programs load the correct version.

Signed-off-by: Simon McVittie <smcv@debian.org>
---
 meson.build                         | 15 +++++++++++++++
 pipewire-jack/src/meson.build       |  5 ++++-
 pipewire-pulseaudio/src/meson.build |  5 ++++-
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index d758f0185..1301a3f80 100644
--- a/meson.build
+++ b/meson.build
@@ -35,6 +35,21 @@ pipewire_sysconfdir = join_paths(prefix, get_option('sysconfdir'))
 
 pipewire_configdir = join_paths(pipewire_sysconfdir, 'pipewire')
 modules_install_dir = join_paths(pipewire_libdir, pipewire_name)
+
+if host_machine.system() == 'linux'
+  # glibc ld.so interprets ${LIB} in a library loading path with an
+  # appropriate value for the current architecture, typically something
+  # like lib, lib64 or lib/x86_64-linux-gnu.
+  # This allows the same pw-pulse script to work for both 32- and 64-bit
+  # applications on biarch/multiarch distributions, by setting something
+  # like LD_LIBRARY_PATH='/usr/${LIB}/pipewire-0.3/pulse'.
+  # Note that ${LIB} is a special token expanded by the runtime linker,
+  # not an environment variable, and must be passed through literally.
+  modules_install_dir_dlopen = join_paths(prefix, '${LIB}', pipewire_name)
+else
+  modules_install_dir_dlopen = modules_install_dir
+endif
+
 spa_plugindir = join_paths(pipewire_libdir, spa_name)
 
 pipewire_headers_dir = join_paths(pipewire_name, 'pipewire')
diff --git a/pipewire-jack/src/meson.build b/pipewire-jack/src/meson.build
index 23c2d8a22..0ea26143b 100644
--- a/pipewire-jack/src/meson.build
+++ b/pipewire-jack/src/meson.build
@@ -20,10 +20,13 @@ jack_dep = dependency('jack', version : '>= 1.9.10', required : false)
 libjack_path = get_option('libjack-path')
 if libjack_path == ''
   libjack_path = join_paths(modules_install_dir, 'jack')
+  libjack_path_dlopen = join_paths(modules_install_dir_dlopen, 'jack')
+else
+  libjack_path_dlopen = libjack_path
 endif
 
 tools_config = configuration_data()
-tools_config.set('LIBJACK_PATH', libjack_path)
+tools_config.set('LIBJACK_PATH', libjack_path_dlopen)
 
 configure_file(input : 'pw-jack.in',
                output : 'pw-jack',
diff --git a/pipewire-pulseaudio/src/meson.build b/pipewire-pulseaudio/src/meson.build
index d700d2d9b..332824f6d 100644
--- a/pipewire-pulseaudio/src/meson.build
+++ b/pipewire-pulseaudio/src/meson.build
@@ -51,10 +51,13 @@ vflag = '-Wl,--version-script,@0@/@1@'.format(meson.current_source_dir(), mapfil
 libpulse_path = get_option('libpulse-path')
 if libpulse_path == ''
   libpulse_path = join_paths(modules_install_dir, 'pulse')
+  libpulse_path_dlopen = join_paths(modules_install_dir_dlopen, 'pulse')
+else
+  libpulse_path_dlopen = libpulse_path
 endif
 
 tools_config = configuration_data()
-tools_config.set('LIBPULSE_PATH', libpulse_path)
+tools_config.set('LIBPULSE_PATH', libpulse_path_dlopen)
 
 configure_file(input : 'pw-pulse.in',
                output : 'pw-pulse',