[Mesa-dev] [PATCH 2/2] fixup! dri3: allow building against older xcb (v3)

[Rob Clark]

---
I'm a bit unsure about the xcb-present version dependency, as that was
added in a different commit.  OTOH I guess Dave is building vulkan with
his patch so it is perhaps not a built-time dependency.

 meson.build | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/meson.build b/meson.build
index c201644c372..30f1919e6f5 100644
--- a/meson.build
+++ b/meson.build
@@ -1235,9 +1235,14 @@ if with_platform_x11
     dep_xcb_dri2 = dependency('xcb-dri2', version : '>= 1.8')
 
     if with_dri3
-      pre_args += ['-DHAVE_DRI3', '-DHAVE_DRI3_MODIFIERS']
-      dep_xcb_dri3 = dependency('xcb-dri3', version : '>= 1.13')
-      dep_xcb_present = dependency('xcb-present', version: '>= 1.13')
+      pre_args += '-DHAVE_DRI3'
+      dep_xcb_dri3 = dependency('xcb-dri3')
+      dep_xcb_present = dependency('xcb-present')
+      # until xcb-dri3 has been around long enough to make a hard-dependency:
+      dep_xcb_dri3_modifiers = dependency('xcb-dri3', version : '>= 1.13', required : false)
+      if dep_xcb_dri3_modifiers.found()
+        pre_args += '-DHAVE_DRI3_MODIFIERS'
+      endif
       dep_xcb_sync = dependency('xcb-sync')
       dep_xshmfence = dependency('xshmfence', version : '>= 1.1')
     endif
-- 
2.14.3