build: Add meson build system files

meson.build

@@ -0,0 +1,62 @@
+project('iio-sensor-proxy', [ 'c' ],
+        version: '2.5',
+        license: 'GPLv2+',
+        default_options: [
+          'buildtype=debugoptimized',
+          'warning_level=1',
+          'c_std=c99',
+        ],
+        meson_version: '>= 0.54.0')
+
+cc = meson.get_compiler('c')
+
+common_cflags = cc.get_supported_arguments([
+    '-fgnu89-inline',
+    '-fvisibility=hidden',
+    '-std=gnu99',
+    '-Wall',
+    '-Wundef',
+    '-Wunused',
+    '-Wstrict-prototypes',
+    '-Werror-implicit-function-declaration',
+    '-Wno-pointer-sign',
+    '-Wshadow'
+])
+
+sbindir = get_option('sbindir')
+bindir = get_option('bindir')
+dbusconfdir = get_option('sysconfdir') / 'dbus-1' / 'system.d'
+
+mathlib_dep = cc.find_library('m', required: false)
+udev_rules_dir = get_option('udevrulesdir')
+if udev_rules_dir == 'auto'
+    udev_dep = dependency('udev')
+    udev_rules_dir = udev_dep.get_pkgconfig_variable('udevdir') + '/rules.d'
+endif
+systemd_system_unit_dir = get_option('systemdsystemunitdir')
+if systemd_system_unit_dir == 'auto'
+    systemd_dep = dependency('systemd')
+    systemd_system_unit_dir = systemd_dep.get_pkgconfig_variable('systemdsystemunitdir')
+endif
+if get_option('gtk-tests')
+    gtk_dep = dependency('gtk+-3.0', required: false)
+endif
+gio_dep = dependency('gio-2.0')
+gudev_dep = dependency('gudev-1.0', version: '>= 232')
+
+gnome = import('gnome')
+
+add_global_arguments('-D_GNU_SOURCE=1', language: 'c')
+
+subdir('src')
+subdir('data')
+
+if get_option('gtk_doc')
+  # Make like license available in the build root for docs
+  configure_file(
+    input: 'COPYING',
+    output: 'COPYING',
+    copy: true,
+  )
+  subdir('docs')
+endif