build: allow building without help in meson

meson.build

@@ -12,6 +12,7 @@ apk_libdir = get_option('libdir')
 
 zlib_dep = dependency('zlib')
 openssl_dep = dependency('openssl')
+lua_bin = find_program('lua' + get_option('lua_version'), required: get_option('help'))
 lua_dep = dependency('lua' + get_option('lua_version'), required: get_option('lua'))
 scdoc_dep = dependency('scdoc', version: '>=1.10', required: get_option('docs'))
 

meson_options.txt

@@ -1,3 +1,4 @@
 option('docs', description: 'Build manpages with scdoc', type: 'feature', value: 'auto')
+option('help', description: 'Build help into apk binaries, needs lua and lua-zlib', type: 'feature', value: 'auto')
 option('lua', description: 'Build luaapk (lua bindings)', type: 'feature', value: 'auto')
 option('lua_version', description: 'Lua version to build against', type: 'string', value: '5.3')

src/meson.build

@@ -54,15 +54,24 @@ apk_src = [
     'help.c',
 ]
 
-genhelp_script = find_program('genhelp.lua')
+if lua_bin.found()
+    genhelp_script = find_program('genhelp.lua')
 
-generated_help = custom_target(
-    'help.h',
-    capture: true,
-    output: 'help.h',
-    input: man_files,
-    command: [genhelp_script, '@INPUT@'],
-)
+    generated_help = custom_target(
+        'help.h',
+        capture: true,
+        output: 'help.h',
+        input: man_files,
+        command: [genhelp_script, '@INPUT@'],
+    )
+else
+    generated_help = custom_target(
+        'help.h',
+        capture: true,
+        output: 'help.h',
+        command: ['echo', '#define NO_HELP'],
+    )
+endif
 
 apk_src += [ generated_help ]