Feature: command line parser enabled var

impl/command_line/meson.build

@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: BSD-3-Clause
-libSubstrateSrcs += files(
+libSubstrateCommandLineSrcs = files(
 	'tokeniser.cxx', 'arguments.cxx', 'options.cxx'
 )

impl/meson.build

@@ -3,9 +3,12 @@ libSubstrateSrcs = [
 	'socket.cxx', 'console.cxx', 'affinity.cxx', 'thread.cxx',
 	'utility.cxx', 'hash.cxx',
 ]
+subdir('command_line')
 
 deps = []
 libSubstrateArgs = []
+# Clone the sources list for the native build if it's required.
+libSubstrateNativeSrcs = [] + libSubstrateSrcs
 
 if target_machine.system() == 'windows'
 	deps += cxx.find_library('ws2_32', required: true)
@@ -125,11 +128,13 @@ if cxxVersion.version_compare('>=201703')
 		name: 'accepts nullptr as part of CTAD with pointer type values (GCC #85977)'
 	)
 
-	if friendTypenameTemplate and stdVariantGCC and stdFilesystemPath and initializerList
+	substrateCommandLineEnabled = friendTypenameTemplate and stdVariantGCC and stdFilesystemPath and initializerList
+	if substrateCommandLineEnabled
 		deps += [libstdcppFS]
-
-		subdir('command_line')
+		libSubstrateSrcs += libSubstrateCommandLineSrcs
 	endif
+else
+	substrateCommandLineEnabled = false
 endif
 
 # This is by far not a complete set of conditions, however..
@@ -203,49 +208,62 @@ endif
 
 # In a cross-build scenario, always build a version of the library for the host too.
 if meson.is_cross_build()
-	hostCXX = meson.get_compiler('cpp', native: true)
+	buildCXX = meson.get_compiler('cpp', native: true)
+
+	depsNative = []
+
+	if build_machine.system() == 'windows'
+		depsNative += buildCXX.find_library('ws2_32', required: true)
+		depsNative += buildCXX.find_library('dbghelp', required: true)
+	else
+		libSubstrateNativeSrcs += 'pty.cxx'
+	endif
 
-	if hostCXX.get_define('__cplusplus').substring(0, -1).version_compare('>=201703')
+	depsNative += dependency('threads', native: true)
+
+	if buildCXX.get_define('__cplusplus').substring(0, -1).version_compare('>=201703')
 		# Re-check if we should or can enable the command line handling stuff by checking
 		# everything again against the host compiler
-		friendTypenameTemplate = hostCXX.compiles(
+		friendTypenameTemplate = buildCXX.compiles(
 			friendTypenameTest,
 			name: 'accepts friend declarations for auto functions (LLVM #31852, #33222)'
 		)
 
-		stdVariantGCC = hostCXX.compiles(
+		stdVariantGCC = buildCXX.compiles(
 			stdVariantGCCTest,
 			name: 'has a working std::variant implementation (GCC #80165)'
 		)
 
 		# GCC < 9.1 splits the filesystem module into a separate library
-		libstdcppFS = hostCXX.find_library('stdc++fs', required: false)
+		libstdcppFS = buildCXX.find_library('stdc++fs', required: false)
 
-		stdFilesystemPath = hostCXX.links(
+		stdFilesystemPath = buildCXX.links(
 			stdFilesystemPathTest,
 			name: 'has a working std::filesystem::path implementation (GCC >= 8 in macOS pre 10.15)',
 			dependencies: libstdcppFS,
 		)
 
-		initializerList = hostCXX.compiles(
+		initializerList = buildCXX.compiles(
 			initializerListTest,
 			name: 'accepts nullptr as part of CTAD with pointer type values (GCC #85977)'
 		)
 
-		if friendTypenameTemplate and stdVariantGCC and stdFilesystemPath and initializerList
-			deps += [libstdcppFS]
-
-			subdir('command_line')
+		substrateNativeCommandLineEnabled = friendTypenameTemplate and stdVariantGCC and stdFilesystemPath and initializerList
+		if substrateNativeCommandLineEnabled
+			depsNative += [libstdcppFS]
+			libSubstrateNativeSrcs += libSubstrateCommandLineSrcs
 		endif
+	else
+		substrateNativeCommandLineEnabled = false
 	endif
 
 	libSubstrateNative = library(
 		'substrateNative',
-		libSubstrateSrcs,
+		libSubstrateNativeSrcs,
 		c_args: ['-DSUBSTRATE_BUILD_INTERNAL'] + libSubstrateArgs,
 		cpp_args: ['-DSUBSTRATE_BUILD_INTERNAL'] + libSubstrateArgs,
 		include_directories: include_directories('..'),
-		dependencies: deps,
+		dependencies: depsNative,
 		gnu_symbol_visibility: 'inlineshidden',
 		implicit_include_directories: false,
 		pic: true,

meson.build

@@ -145,6 +145,9 @@ if not meson.is_subproject() and get_option('build_library')
 		libraries: [libSubstrate, deps],
 		version: meson.project_version(),
 		extra_cflags: libSubstrateArgs,
+		variables: [
+			'command_line_enabled=@0@'.format(substrateCommandLineEnabled),
+		],
 		description: 'A collection of headers containing useful tools and gadgets for building C++ programs'
 	)
 endif
@@ -155,6 +158,7 @@ variablesCompileArgs = [
 
 variables = {
 	'compile_args': ' '.join(variablesCompileArgs),
+	'command_line_enabled': substrateCommandLineEnabled.to_string(),
 }
 
 nativeDeps = deps
@@ -187,13 +191,14 @@ endif
 if meson.is_cross_build()
 	substrateNativeArgs = ' '.join(['-I@0@'.format(meson.current_source_dir())] + libSubstrateArgs)
 	substrateNative_dep = declare_dependency(
-		dependencies: deps,
+		dependencies: depsNative,
 		include_directories: include_directories('.'),
 		compile_args: substrateNativeArgs,
 		link_with: libSubstrateNative,
 		variables: {
 			'compile_args': substrateNativeArgs,
-			'link_args': libSubstrateNative.full_path()
+			'link_args': libSubstrateNative.full_path(),
+			'command_line_enabled': substrateNativeCommandLineEnabled.to_string(),
 		},
 		version: meson.project_version()
 	)