meson.build: install symbolic links instead of compiling multiple times

Currently, among others, the `pipewire-pulse` executable is an
exact copy of the `pipewire` executable. Use meson's
`install_symlink()` to avoid the need for compiling the same thing
multiple times. Also use `custom_target()` so that the aliases
are available in an uninstalled environment.

Do the same for `pw-cat`. The benefit is that all aliases
of `pw-cat` are now available in an uninstalled environment.

This commit increasese the minimum meson version to 0.61.1
as that is needed for `install_symlink()`.

The reason for using 0.61.1 instead of 0.61.0 is the following bug:
https://github.com/mesonbuild/meson/issues/9820

meson.build

@@ -1,7 +1,7 @@
 project('pipewire', ['c' ],
   version : '0.3.67',
   license : [ 'MIT', 'LGPL-2.1-or-later', 'GPL-2.0-only' ],
-  meson_version : '>= 0.59.0',
+  meson_version : '>= 0.61.1',
   default_options : [ 'warning_level=3',
                       'c_std=gnu11',
                       'cpp_std=c++17',

src/daemon/meson.build

@@ -89,30 +89,7 @@ configure_file(input : 'pipewire.conf.in',
 pipewire_exec = executable('pipewire',
   pipewire_daemon_sources,
   install: true,
-  c_args : pipewire_c_args,
-  include_directories : [ configinc ],
-  dependencies : [ spa_dep, pipewire_dep, ],
-)
-
-executable('pipewire-pulse',
-  pipewire_daemon_sources,
-  install: true,
-  c_args : pipewire_c_args,
-  include_directories : [ configinc ],
-  dependencies : [ spa_dep, pipewire_dep, ],
-)
-
-executable('pipewire-avb',
-  pipewire_daemon_sources,
-  install: true,
-  c_args : pipewire_c_args,
-  include_directories : [ configinc ],
-  dependencies : [ spa_dep, pipewire_dep, ],
-)
-
-executable('pipewire-aes67',
-  pipewire_daemon_sources,
-  install: true,
+  install_dir: pipewire_bindir,
   c_args : pipewire_c_args,
   include_directories : [ configinc ],
   dependencies : [ spa_dep, pipewire_dep, ],
@@ -120,6 +97,22 @@ executable('pipewire-aes67',
 
 ln = find_program('ln')
 
+foreach alias : ['pipewire-pulse', 'pipewire-avb', 'pipewire-aes67']
+  custom_target(
+    alias,
+    build_by_default: true,
+    install: false,
+    command: [ln, '-sf', meson.project_build_root() + '/@INPUT@', '@OUTPUT@'],
+    input: pipewire_exec,
+    output: alias,
+  )
+  install_symlink(
+    alias,
+    pointing_to: pipewire_exec.name(),
+    install_dir: pipewire_bindir,
+  )
+endforeach
+
 custom_target('pipewire-uninstalled',
   build_by_default: true,
   install: false,

src/tools/meson.build

@@ -58,16 +58,26 @@ if get_option('pw-cat').allowed() and sndfile_dep.found()
     'pw-encplay',
   ]
 
-  executable('pw-cat',
+  pw_cat = executable('pw-cat',
     pwcat_sources,
     install: true,
     dependencies : [pwcat_deps, pipewire_dep, mathlib],
   )
 
   foreach alias : pwcat_aliases
-    dst = pipewire_bindir / alias
-    cmd = 'ln -fs @0@ $DESTDIR@1@'.format('pw-cat', dst)
-    meson.add_install_script('sh', '-c', cmd)
+    custom_target(
+      alias,
+      build_by_default: true,
+      install: false,
+      command: [ln, '-sf', meson.project_build_root() + '/@INPUT@', '@OUTPUT@'],
+      input: pw_cat,
+      output: alias,
+    )
+    install_symlink(
+      alias,
+      pointing_to: pw_cat.name(),
+      install_dir: pipewire_bindir,
+    )
   endforeach
 elif not sndfile_dep.found() and get_option('pw-cat').enabled()
   error('pw-cat is enabled but required dependency `sndfile` was not found.')