CLI cleanups; fix the FreeBSD build

6 files changed, 43 insertions, 63 deletions

diff --git a/nihil.cli/CMakeLists.txt b/nihil.cli/CMakeLists.txt
index 091c34f..859fea5 100644
--- a/nihil.cli/CMakeLists.txt
+++ b/nihil.cli/CMakeLists.txt
@@ -4,6 +4,7 @@ add_library(nihil.cli STATIC)
 target_link_libraries(nihil.cli PRIVATE
 	nihil.std
 	nihil.generator
+	nihil.posix;
 	nihil.util
 )
 target_sources(nihil.cli
@@ -18,7 +19,6 @@ target_sources(nihil.cli
 
 	PRIVATE
 	dispatch_command.cc
-	registry.cc
 )
 
 if(NIHIL_TESTS)
diff --git a/nihil.cli/command.ccm b/nihil.cli/command.ccm
index dc3f29a..ea52bbf 100644
--- a/nihil.cli/command.ccm
+++ b/nihil.cli/command.ccm
@@ -31,15 +31,24 @@ export struct command final
 {
 	using command_handler_t = std::function<int(int, char **)>;
 
-	command(std::string_view const path, std::string_view const usage, command_handler_t handler) noexcept
-		: m_path(path)
+	// Construct a new command with a handler and register it.  Since this is usually invoked
+	// at global scope by static object construction, we handle exception internally.
+	command(std::string_view const path, std::string_view const usage, auto &&handler) noexcept
+	try	: m_path(path)
 		, m_usage(usage)
-		, m_handler(std::move(handler))
+		, m_handler(std::forward<decltype(handler)>(handler))
 	{
 		register_command(this);
+	} catch (std::exception const &exc) {
+		std::println(std::cerr, "register_command(): {}", exc.what());
+		std::quick_exit(1);
+	} catch (...) {
+		std::println(std::cerr, "register_command(): unknown error");
+		std::quick_exit(1);
 	}
 
-	explicit command(std::string_view const path) noexcept
+	// Create a stub command which doesn't have a handler.
+	explicit command(std::string_view const path)
 		: m_path(path)
 	{
 	}
diff --git a/nihil.cli/command_tree.ccm b/nihil.cli/command_tree.ccm
index 7399357..8ed16c7 100644
--- a/nihil.cli/command_tree.ccm
+++ b/nihil.cli/command_tree.ccm
@@ -166,7 +166,7 @@ private:
 {
 	auto tree = command_tree();
 
-	for (auto &&command : get_registered_commands()) {
+	for (auto &&command : get_registry()) {
 		// Throws std::logic_error on duplicates.
 		tree.insert(command);
 	}
diff --git a/nihil.cli/dispatch_command.cc b/nihil.cli/dispatch_command.cc
index 6e3a757..e9bf779 100644
--- a/nihil.cli/dispatch_command.cc
+++ b/nihil.cli/dispatch_command.cc
@@ -9,6 +9,7 @@ module nihil.cli;
 
 import nihil.std;
 import nihil.core;
+import nihil.posix;
 
 namespace nihil {
 
@@ -17,11 +18,11 @@ namespace {
 auto print_commands(command_tree_node const &node) -> void
 {
 	for (auto &&child : node.children())
-		std::print(std::cerr, "  {}\n", child.command().path());
+		std::println(std::cerr, "  {}", child.command().path());
 }
 } // namespace
 
-auto dispatch_command(int argc, char **argv) -> int
+auto dispatch_command(int const argc, char **argv) -> int
 {
 	// Reset getopt(3) for the command, in case main() used it already.
 	optreset = 1;
@@ -35,12 +36,8 @@ auto dispatch_command(int argc, char **argv) -> int
 	// Set the program name to the existing progname plus the full path to the command being
 	// invoked; this makes error messages nicer. Save the old progname so we can restore it
 	// after invoking the command.
-	auto const *old_progname = ::getprogname();
-
-	{
-		auto cprogname = std::format("{} {}", ::getprogname(), command.path());
-		::setprogname(cprogname.c_str());
-	}
+	auto progname_guard =
+		setprogname(std::format("{} {}", getprogname().value_or(""), command.path()));
 
 	// Invoke the command see what it returns.  If it's an exit code, just return it.
 	// Otherwise, handle the error.
@@ -51,7 +48,7 @@ auto dispatch_command(int argc, char **argv) -> int
 	auto ret = command.invoke(nrest, argv + (argc - nrest));
 
 	// Restore the old progname.
-	::setprogname(old_progname);
+	progname_guard.release();
 
 	if (ret)
 		return *ret;
diff --git a/nihil.cli/registry.cc b/nihil.cli/registry.cc
deleted file mode 100644
index a972a65..0000000
--- a/nihil.cli/registry.cc
+++ /dev/null
@@ -1,43 +0,0 @@
-// This source code is released into the public domain.
-module nihil.cli;
-
-import nihil.std;
-
-namespace nihil {
-
-//  Get the registry storage.  Because this is called from global ctors,
-//  it handles exceptions itself.
-auto get_registry() noexcept -> std::vector<std::shared_ptr<command>> &
-try {
-	static auto commands = std::vector<std::shared_ptr<command>>();
-	return commands;
-} catch (std::exception const &exc) {
-	std::println(std::cerr, "{}", exc.what());
-	std::exit(1); // NOLINT
-} catch (...) {
-	std::println(std::cerr, "get_registered_commands(): unknown error\n");
-	std::exit(1); // NOLINT
-}
-
-// Register a new command.
-auto register_command(command *cmd) noexcept -> void
-try {
-	auto null_deleter = [] (command const *) -> void {};
-
-	auto &commands = get_registry();
-	commands.emplace_back(cmd, null_deleter);
-} catch (std::exception const &exc) {
-	std::println(std::cerr, "{}", exc.what());
-	std::exit(1); // NOLINT
-} catch (...) {
-	std::println(std::cerr, "get_registered_commands(): unknown error\n");
-	std::exit(1); // NOLINT
-}
-
-// Get the list of registered commands.
-auto get_registered_commands() -> std::span<std::shared_ptr<command>>
-{
-	return {get_registry()};
-}
-
-} // namespace nihil
diff --git a/nihil.cli/registry.ccm b/nihil.cli/registry.ccm
index e5a7e29..5e31195 100644
--- a/nihil.cli/registry.ccm
+++ b/nihil.cli/registry.ccm
@@ -7,11 +7,28 @@ namespace nihil {
 
 export struct command;
 
-// Register a command.  This is guaranteed not to throw; errors will print
-// a diagnostic and exit.
-auto register_command(command *cmd) noexcept -> void;
+///////////////////////////////////////////////////////////////////////
+// Command registry storage.  This is where command::command() registers
+// itself when the global command objects are constructed at startup.
+//
+// Because we sometimes create stub commands dynamically, the registry
+// storage is a list of shared_ptr<command>.  The "real" commands (which
+// refer to global objects) will be created with a null deleter so they
+// are never deleted.  This allows real and stub commands to mix in the
+// same command_tree.
 
-// Get previously registered commands.
-auto get_registered_commands() -> std::span<std::shared_ptr<command>>;
+//  Get the current registry.
+auto get_registry() -> std::vector<std::shared_ptr<command>> &
+{
+	static auto commands = std::vector<std::shared_ptr<command>>();
+	return commands;
+}
+
+// Register a new command.
+auto register_command(command *cmd) noexcept -> void
+{
+	auto constexpr null_deleter = [] (command const *) -> void {};
+	get_registry().emplace_back(cmd, null_deleter);
+}
 
 } // namespace nihil