build: consolidate lcms2 dependencies

It's bad form to set the same variable in multiple places, and not all
of them were even equivalent.

Move lcms2 finding to the root level build file only. It is still an
optional dependency like before, and the if-not-found checks are still
in place where actually needed.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

compositor/meson.build

@@ -97,18 +97,17 @@ if get_option('screenshare')
 endif
 
 if get_option('color-management-lcms')
-	config_h.set('HAVE_LCMS', '1')
-
 	srcs_lcms = [
 		'cms-static.c',
 		'cms-helper.c',
 	]
 
-	dep_lcms2 = dependency('lcms2', required: false)
 	if not dep_lcms2.found()
 		error('cms-static requires lcms2 which was not found. Or, you can use \'-Dcolor-management-lcms=false\'.')
 	endif
 
+	config_h.set('HAVE_LCMS', '1')
+
 	plugin_lcms = shared_library(
 		'cms-static',
 		srcs_lcms,

libweston/color-lcms/meson.build

@@ -2,7 +2,6 @@ if not get_option('color-management-lcms')
 	subdir_done()
 endif
 
-dep_lcms2 = dependency('lcms2', version: '>= 2.9', required: false)
 if not dep_lcms2.found()
 	error('color-lcms plugin requires lcms2 which was not found. Or, you can use \'-Dcolor-management-lcms=false\'.')
 endif

meson.build

@@ -158,6 +158,8 @@ if dep_libdrm_version.version_compare('>=2.4.107')
   config_h.set('HAVE_HUMAN_FORMAT_MODIFIER', '1')
 endif
 
+dep_lcms2 = dependency('lcms2', version: '>= 2.9', required: false)
+
 prog_python = import('python').find_installation('python3')
 files_xxd_py = files('tools/xxd.py')
 cmd_xxd = [ prog_python, files_xxd_py, '@INPUT@', '@OUTPUT@' ]

tests/meson.build

@@ -239,7 +239,6 @@ if get_option('renderer-gl')
 endif
 
 if get_option('color-management-lcms')
-	dep_lcms2 = dependency('lcms2', version: '>= 2.9', required: false)
 	if not dep_lcms2.found()
 		error('color-management-lcms tests require lcms2 which was not found. Or, you can use \'-Dcolor-management-lcms=false\'.')
 	endif