wp-uninstalled: build this script with the meson dirs filled in

./builddir/wp-uninstalled.sh can now be called without a -b argument,
it'll automatically set the full paths. This is useful when building as
a subproject.

meson has a limitation: the configure_file() object is just a file
wrapper object. Wrap this into a custom_target() whose return value has
a full_path() method. This way, pipewire can use
wireplumber_uninstalled.full_path() without having to build the
directory structure itself.

meson.build

@@ -118,3 +118,21 @@ subdir('src')
 if get_option('tests')
   subdir('tests')
 endif
+
+conf_uninstalled = configuration_data()
+conf_uninstalled.set('MESON', '')
+conf_uninstalled.set('MESON_SOURCE_ROOT', meson.project_source_root())
+conf_uninstalled.set('MESON_BUILD_ROOT', meson.project_build_root())
+
+wp_uninstalled = configure_file(
+  input : 'wp-uninstalled.sh',
+  output : 'wp-uninstalled.sh.in',
+  configuration : conf_uninstalled,
+)
+
+wireplumber_uninstalled = custom_target('wp-uninstalled',
+  output : 'wp-uninstalled.sh',
+  input : wp_uninstalled,
+  build_by_default : true,
+  command : ['cp', '@INPUT@', '@OUTPUT@'],
+)

wp-uninstalled.sh

@@ -2,8 +2,14 @@
 
 set -e
 
-SOURCEDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
-BUILDDIR=${SOURCEDIR}/build
+# This is unset by meson
+if [ -z "@MESON@" ]; then
+  SOURCEDIR="@MESON_SOURCE_ROOT@"
+  BUILDDIR="@MESON_BUILD_ROOT@"
+else
+  SOURCEDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+  BUILDDIR=${SOURCEDIR}/build
+fi
 CONFIGDIR=config
 
 while getopts ":b:c:" opt; do