Rebased From b693feda0148eb421e1f59d468caceb6f3183a82 Mon Sep 17 00:00:00 2001
From: Mart Raudsepp <mart@leio.tech>
Date: Mon, 16 Mar 2020 23:43:12 +0200
Subject: [PATCH] build: Handle lua as needed by Gentoo

Gentoo currently uses unversioned lua:0 - lua.pc instad of lua5.1.pc,
/usr/bin/lua instead of /usr/bin/lua5.1
Additionally lua and luajit can be installed in parallel, but only one
should be chosen - so add explicit meson options to choose between them.
This is currently in a hacky un-upstreamable way: working correctly only
if both options are disabled, or only one is enabled and the other
disabled, but having logic issues if any is "auto" or both enabled; this
is because feature option is mainly used to handle explicit choice
between them more easily in a Gentoo-specific patch without having to
add various conditional branches thanks to the feature being disabled
acting as a full disabler, so the other option is automatically not
checked.
--- a/meson.build
+++ b/meson.build
@@ -144,18 +144,12 @@ if not python3_dep.found() or python_path != ''
 endif
 
 pygobject_dep = dependency('pygobject-3.0', version: pygobject_req, required: false)
-lua51_dep = dependency('lua51', version: lua_req, required: false)
-if not lua51_dep.found()
-  lua51_dep = dependency('lua-5.1', version: lua_req, required: false)
-endif
-luajit_dep = dependency('luajit', version: luajit_req, required: false)
+lua51_dep = dependency('lua', version: lua_req, required: get_option('lua51'))
+luajit_dep = dependency('luajit', version: luajit_req, required: get_option('luajit'))
 lua_lgi_found = false
 lua_lgi_ver = 'not found'
-lua51_prg = find_program('lua5.1', required: false)
-if not lua51_prg.found()
-  lua51_prg = find_program('lua51', required: false)
-endif
-luajit_prg = find_program('luajit', required: false)
+lua51_prg = find_program('lua', required: get_option('lua51'))
+luajit_prg = find_program('luajit', required: get_option('luajit'))
 xmllint_prg = find_program('xmllint', required: false)
 generate_vapi = get_option('vapi')
 vapigen_prg = find_program('vapigen', required: generate_vapi)
@@ -217,6 +211,8 @@ if lua_found
             lua51_lgi_dep = declare_dependency(version: lua_lgi_ver)
             lua_lgi_found = true
         endif
+    else
+        error('lua support requested but lua-lgi not found')
     endif
     message('lua-lgi version: ' + lua_lgi_ver)
 endif
@@ -402,11 +398,7 @@ endif
 
 build_gjs_loader = get_option('gjs')
 
-build_lua51_loader = get_option('lua51')
-lua51_found = (luajit_dep.found() or lua51_dep.found()) and lua_lgi_found
-if build_lua51_loader and not lua51_found
-  error('Lua51 requested but failed to locate suitable Lua51 and LGI support')
-endif
+build_lua51_loader = (luajit_dep.found() or lua51_dep.found()) and lua_lgi_found
 
 build_python3_loader = get_option('python3')
 python3_found = python3_dep.found() and pygobject_dep.found()
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -3,8 +3,11 @@ option('gjs',
        description: 'Enable GJS support (requires gjs-1.0)')
 
 option('lua51',
-       type: 'boolean', value: true,
+       type: 'feature', value: 'enabled',
        description: 'Enable Lua 5.1 support (requires lua-lgi)')
+option('luajit',
+       type: 'feature', value: 'disabled',
+       description: 'Use LuaJIT for Lua 5.1 support (requires lua-lgi)')
 
 option('python3',
        type: 'boolean', value: true,