[libdazzle: 1/2] build: set PLATFORM_OSX on macOS

[Christian Hergert <chergert src gnome org>]

commit 62eb186757b525c20d3c029392bf3ebf04406b85
Author: Tom Schoonjans <Tom Schoonjans rfi ac uk>
Date:   Thu Jun 10 08:59:27 2021 +0100

    build: set PLATFORM_OSX on macOS
    
    Since this will add some objective-c code to the build, compilation must
    then occur with the -xobjective-c flag.

 meson.build     | 6 ++++++
 src/meson.build | 4 ++++
 2 files changed, 10 insertions(+)
---
diff --git a/meson.build b/meson.build
index 3296ad5..9a2c157 100644
--- a/meson.build
+++ b/meson.build
@@ -39,6 +39,12 @@ add_project_arguments([
   '-DDAZZLE_COMPILATION',
 ], language: 'c')
 
+if host_machine.system() == 'darwin'
+  add_project_arguments([
+    '-DPLATFORM_OSX',
+  ], language: 'c')
+endif
+
 root_inc = include_directories('.')
 src_inc = include_directories('src')
 
diff --git a/src/meson.build b/src/meson.build
index b7e298d..eeb20c5 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -97,6 +97,10 @@ if get_option('enable_rdtscp')
   libdazzle_args += '-DDZL_HAVE_RDTSCP'
 endif
 
+if host_machine.system() == 'darwin'
+  libdazzle_args += '-xobjective-c'
+endif
+
 libdazzle = shared_library(
   'dazzle-' + apiversion,
   libdazzle_sources,