Meson: port dub configurations to Meson options

meson.build

@@ -1,6 +1,6 @@
 project('eventcore', 'd',
-    meson_version: '>=0.50',
-    version: '0.9.13'
+	meson_version: '>=0.53',
+	version: '0.9.13',
 )
 
 project_soversion      = '0'
@@ -10,11 +10,110 @@ project_version_full   = project_version + project_version_suffix
 
 taggedalgebraic_dep = dependency('taggedalgebraic', version: ['>=0.10.12', '<0.12'])
 
+eventcore_build_versions = []
+eventcore_extra_deps = []
+
+default_driver = 'select'
+host_system = host_machine.system()
+
+host_is_posix = false
+host_is_osx = false
+host_is_windows = false
+host_is_bsd = false
+host_is_linux = false
+
+# Determine the default driver if 'driver' was not explicitly set
+if host_system == 'linux'
+	host_is_linux = true
+	host_is_posix = true
+elif host_system == 'windows'
+	host_is_windows = true
+elif host_system == 'dragonfly' or host_system == 'freebsd' or host_system == 'netbsd' or host_system == 'openbsd'
+	host_is_bsd = true
+	host_is_posix = true
+else
+	# What are we running on?
+	default_driver = 'generic'
+endif
+
+if host_is_linux
+	default_driver = 'epoll'
+elif host_is_osx
+	default_driver = 'cfrunloop'
+elif host_is_windows
+	default_driver = 'winapi'
+elif host_is_bsd
+	default_driver = 'kqueue'
+elif host_is_posix
+	default_driver = 'select'
+endif
+
+# Optional dependencies
+libasync_dep = dependency('libasync', version: '~>0.8.2', required: false)
+gaia_dep = dependency('anl', required: get_option('use_gaia'))
+
+# Driver logic
+driver_opt = get_option('driver')
+if driver_opt == 'auto'
+	driver_opt = default_driver
+endif
+
+if driver_opt == 'epoll' 
+	if not host_is_linux
+		error('epoll driver is only supported on Linux')
+	endif
+	eventcore_build_versions += ['EventcoreEpollDriver']
+	if gaia_dep.found()
+		eventcore_extra_deps += [gaia_dep]
+		eventcore_build_versions += ['EventcoreUseGAIA']
+	endif
+elif driver_opt == 'cfrunloop' 
+	if not host_is_osx
+		error('cfrunloop driver is only supported on OSX')
+	endif
+	eventcore_build_versions += ['EventcoreCFRunLoopDriver']
+elif driver_opt == 'kqueue'
+	if not host_is_bsd
+		error('kqueue driver is only supported on BSD variants (including OSX)')
+	endif
+	eventcore_build_versions += ['EventcoreKqueueDriver']
+elif driver_opt == 'winapi'
+	if not host_is_windows
+		error('winapi driver is only supported on Windows')
+	endif
+	eventcore_build_versions += ['EventcoreWinAPIDriver']
+elif driver_opt == 'select' 
+	if not (host_is_posix or host_is_windows)
+		error('select driver is only supported on POSIX-like systems and Windows')
+	endif
+	eventcore_build_versions += ['EventcoreSelectDriver']
+elif driver_opt == 'libasync' 
+	if not libasync_dep.found()
+		error('libasync could not be found, but is required for the libasync driver')
+	endif
+	eventcore_build_versions += ['EventcoreLibasyncDriver']
+	eventcore_extra_deps += [libasync_dep]
+elif driver_opt == 'generic'
+	# Defines eventDriver as the generic EventDriver interface. Setup must be done manually.
+else
+	error('No combination of driver and compatible host machine OS specified')
+endif
+
+summary(
+	{
+		'Chosen driver': driver_opt,
+		'Default driver': default_driver,
+		'Using GAIA': gaia_dep.found()
+	}, 
+	bool_yn: true
+)
+	
+
 source_root = meson.source_root()
 build_root = meson.build_root()
 subdir('source/eventcore')
 
 eventcore_dep = declare_dependency(
-    include_directories: include_directories('source'),
-    link_with: eventcore_lib
+	include_directories: include_directories('source'),
+	link_with: eventcore_lib
 )

meson_options.txt

@@ -0,0 +1,8 @@
+option('driver', 
+    type: 'combo', 
+    choices: ['epoll', 'cfrunloop', 'kqueue', 'winapi', 'select', 'libasync', 'generic', 'auto'], 
+    value: 'auto',
+    description: 'Which async backend driver to use',
+    yield: true
+)
+option('use_gaia', type: 'feature', value: 'auto')

source/eventcore/meson.build

@@ -2,6 +2,7 @@ eventcore_src = [
 	'core.d',
 	'driver.d',
 	'drivers/libasync.d',
+	'drivers/posix/cfrunloop.d',
 	'drivers/posix/dns.d',
 	'drivers/posix/driver.d',
 	'drivers/posix/epoll.d',
@@ -26,11 +27,12 @@ eventcore_src = [
 	'drivers/winapi/sockets.d',
 	'drivers/winapi/watchers.d',
 	'internal/consumablequeue.d',
+	'internal/corefoundation.d',
 	'internal/dlist.d',
+	'internal/ioworker.d',
 	'internal/utils.d',
 	'internal/win32.d',
 	'socket.d',
-
 ]
 
 eventcore_lib = library(
@@ -39,7 +41,8 @@ eventcore_lib = library(
 	version: project_version,
 	install: true,
 	include_directories: include_directories('../'),
-	dependencies: taggedalgebraic_dep,
+	dependencies: [taggedalgebraic_dep, eventcore_extra_deps],
+	d_module_versions: eventcore_build_versions
 )
 
 pkgc = import('pkgconfig')
@@ -47,11 +50,33 @@ pkgc = import('pkgconfig')
 pkgc.generate(
 	eventcore_lib,
 	subdirs: 'd/eventcore',
+	d_module_versions: eventcore_build_versions
 )
 
-install_headers(
-	eventcore_src,
-	subdir: 'd/eventcore/eventcore',
+# This is using install_subdir instead of install_headers, since
+# install_headers flattens the headers directory, it turns
+# ├ ...
+# ├ driver.d
+# ├ drivers
+# │  ├ libasync.d
+# │  ├ ...
+# │  └ winapi
+# │    └ ...
+# ├ ...
+# └ socket.d
+# 
+# into
+# 
+# ├ ...
+# ├ drivers.d
+# ├ libasync.d
+# ├ ...
+# └ socket.d
+# 
+
+install_subdir(
+	'../',
+	install_dir: 'include/d/eventcore/eventcore',
 )
 
 test_exe = executable(
@@ -59,7 +84,8 @@ test_exe = executable(
 	eventcore_src,
 	include_directories: include_directories('../'),
 	d_unittest: true,
-	d_args: '-main',
+	d_args: meson.get_compiler('d').unittest_args(),
+	link_args: '-main',
 	dependencies: taggedalgebraic_dep,
 )