meson: change "cairo" from a boolean to a feature option

We require cairo only to run all tests and thus default it to false.
This usually results in developers not using it when working on changes and
tests depending on cairo then failing in CI.

This changes it to a feature option that defaults to auto, so that devs that
have cairo headers installed will automatically use it.

1 files changed, 19 insertions, 7 deletions

diff --git a/meson.build b/meson.build
index 9025388f..c71d2d84 100644
--- a/meson.build
+++ b/meson.build
@@ -144,19 +144,31 @@ endif
 libffi_dep = dependency('libffi',
   fallback : ['libffi', 'ffi_dep'])
 
-with_cairo = get_option('cairo')
+# cairo
+cairo_option = get_option('cairo')
+if cc.get_id() == 'msvc'
+  if cairo_option.disabled()
+    req = cairo_option
+  else
+    req = false
+  endif
 
-if with_cairo
-  cairo_dep = dependency('cairo', required: cc.get_id() != 'msvc')
-  cairo_gobject_dep = dependency('cairo-gobject', required: cc.get_id() != 'msvc')
+  cairo_dep = dependency('cairo', required: req)
+  cairo_gobject_dep = dependency('cairo-gobject', required: req)
 
-  if cc.get_id() == 'msvc' and (not cairo_gobject_dep.found() or not cairo_dep.found())
+  if not cairo_gobject_dep.found() or not cairo_dep.found()
     if cc.has_header('cairo.h') and cc.has_header ('cairo-gobject.h')
-      cairo_dep = cc.find_library ('cairo')
-      cairo_gobject_dep = cc.find_library ('cairo-gobject')
+      cairo_dep = cc.find_library('cairo', required: cairo_option)
+      cairo_gobject_dep = cc.find_library('cairo-gobject', required: cairo_option)
     endif
   endif
 else
+  cairo_dep = dependency('cairo', required: cairo_option)
+  cairo_gobject_dep = dependency('cairo-gobject', required: cairo_option)
+endif
+cairo_deps_found = cairo_gobject_dep.found() and cairo_dep.found()
+
+if not cairo_deps_found
   warning('Not building with cairo support, not all tests will be run')
 endif