diff --git a/src/libutil/args.cc b/src/libutil/args.cc index 35686a8aa..fc009592c 100644 --- a/src/libutil/args.cc +++ b/src/libutil/args.cc @@ -52,7 +52,7 @@ std::shared_ptr completions; std::string completionMarker = "___COMPLETE___"; -std::optional needsCompletion(std::string_view s) +static std::optional needsCompletion(std::string_view s) { if (!completions) return {}; auto i = s.find(completionMarker); @@ -120,6 +120,12 @@ void Args::parseCmdline(const Strings & _cmdline) if (!argsSeen) initialFlagsProcessed(); + + /* Now that we are done parsing, make sure that any experimental + * feature required by the flags is enabled */ + for (auto & f : flagExperimentalFeatures) + experimentalFeatureSettings.require(f); + } bool Args::processFlag(Strings::iterator & pos, Strings::iterator end) @@ -128,12 +134,18 @@ bool Args::processFlag(Strings::iterator & pos, Strings::iterator end) auto process = [&](const std::string & name, const Flag & flag) -> bool { ++pos; + + if (auto & f = flag.experimentalFeature) + flagExperimentalFeatures.insert(*f); + std::vector args; bool anyCompleted = false; for (size_t n = 0 ; n < flag.handler.arity; ++n) { if (pos == end) { if (flag.handler.arity == ArityAny || anyCompleted) break; - throw UsageError("flag '%s' requires %d argument(s)", name, flag.handler.arity); + throw UsageError( + "flag '%s' requires %d argument(s), but only %d were given", + name, flag.handler.arity, n); } if (auto prefix = needsCompletion(*pos)) { anyCompleted = true; @@ -152,7 +164,11 @@ bool Args::processFlag(Strings::iterator & pos, Strings::iterator end) for (auto & [name, flag] : longFlags) { if (!hiddenCategories.count(flag->category) && hasPrefix(name, std::string(*prefix, 2))) + { + if (auto & f = flag->experimentalFeature) + flagExperimentalFeatures.insert(*f); completions->add("--" + name, flag->description); + } } return false; } @@ -172,7 +188,8 @@ bool Args::processFlag(Strings::iterator & pos, Strings::iterator end) if (prefix == "-") { completions->add("--"); for (auto & [flagName, flag] : shortFlags) - completions->add(std::string("-") + flagName, flag->description); + if (experimentalFeatureSettings.isEnabled(flag->experimentalFeature)) + completions->add(std::string("-") + flagName, flag->description); } } @@ -219,6 +236,8 @@ nlohmann::json Args::toJSON() auto flags = nlohmann::json::object(); for (auto & [name, flag] : longFlags) { + /* Skip experimental flags when listing flags. */ + if (!experimentalFeatureSettings.isEnabled(flag->experimentalFeature)) continue; auto j = nlohmann::json::object(); if (flag->aliases.count(name)) continue; if (flag->shortName) diff --git a/src/libutil/args.hh b/src/libutil/args.hh index 7211ee307..2969806dd 100644 --- a/src/libutil/args.hh +++ b/src/libutil/args.hh @@ -117,6 +117,8 @@ protected: Handler handler; std::function completer; + std::optional experimentalFeature; + static Flag mkHashTypeFlag(std::string && longName, HashType * ht); static Flag mkHashTypeOptFlag(std::string && longName, std::optional * oht); }; @@ -188,6 +190,16 @@ public: friend class MultiCommand; MultiCommand * parent = nullptr; + +private: + + /** + * Experimental features needed when parsing args. These are checked + * after flag parsing is completed in order to support enabling + * experimental features coming after the flag that needs the + * experimental feature. + */ + std::set flagExperimentalFeatures; }; /* A command is an argument parser that can be executed by calling its @@ -253,8 +265,6 @@ enum CompletionType { }; extern CompletionType completionType; -std::optional needsCompletion(std::string_view s); - void completePath(size_t, std::string_view prefix); void completeDir(size_t, std::string_view prefix); diff --git a/src/libutil/config.cc b/src/libutil/config.cc index 0dbb4de81..8d63536d6 100644 --- a/src/libutil/config.cc +++ b/src/libutil/config.cc @@ -170,9 +170,13 @@ std::string Config::toKeyValue() void Config::convertToArgs(Args & args, const std::string & category) { - for (auto & s : _settings) - if (applicable(s.second)) + for (auto & s : _settings) { + /* We do include args for settings gated on disabled + experimental-features. The args themselves however will also be + gated on any experimental feature the underlying setting is. */ + if (!s.second.isAlias) s.second.setting->convertToArg(args, category); + } } AbstractSetting::AbstractSetting( @@ -219,6 +223,7 @@ void BaseSetting::convertToArg(Args & args, const std::string & category) .category = category, .labels = {"value"}, .handler = {[this](std::string s) { overridden = true; set(s); }}, + .experimentalFeature = experimentalFeature, }); if (isAppendable()) @@ -228,6 +233,7 @@ void BaseSetting::convertToArg(Args & args, const std::string & category) .category = category, .labels = {"value"}, .handler = {[this](std::string s) { overridden = true; set(s, true); }}, + .experimentalFeature = experimentalFeature, }); } @@ -279,13 +285,15 @@ template<> void BaseSetting::convertToArg(Args & args, const std::string & .longName = name, .description = fmt("Enable the `%s` setting.", name), .category = category, - .handler = {[this]() { override(true); }} + .handler = {[this]() { override(true); }}, + .experimentalFeature = experimentalFeature, }); args.addFlag({ .longName = "no-" + name, .description = fmt("Disable the `%s` setting.", name), .category = category, - .handler = {[this]() { override(false); }} + .handler = {[this]() { override(false); }}, + .experimentalFeature = experimentalFeature, }); } diff --git a/src/libutil/util.hh b/src/libutil/util.hh index 52ca36fd1..c4ea6c34b 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -450,7 +450,6 @@ template Strings quoteStrings(const C & c) return res; } - /* Remove trailing whitespace from a string. FIXME: return std::string_view. */ std::string chomp(std::string_view s); diff --git a/src/nix/main.cc b/src/nix/main.cc index da920615f..c79d39459 100644 --- a/src/nix/main.cc +++ b/src/nix/main.cc @@ -54,12 +54,11 @@ static bool haveInternet() std::string programPath; -struct HelpRequested { }; - struct NixArgs : virtual MultiCommand, virtual MixCommonArgs { bool useNet = true; bool refresh = false; + bool helpRequested = false; bool showVersion = false; NixArgs() : MultiCommand(RegisterCommand::getCommandsFor({})), MixCommonArgs("nix") @@ -74,7 +73,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs .longName = "help", .description = "Show usage information.", .category = miscCategory, - .handler = {[&]() { throw HelpRequested(); }}, + .handler = {[this]() { this->helpRequested = true; }}, }); addFlag({ @@ -337,7 +336,11 @@ void mainWrapped(int argc, char * * argv) try { args.parseCmdline(argvToStrings(argc, argv)); - } catch (HelpRequested &) { + } catch (UsageError &) { + if (!args.helpRequested && !completions) throw; + } + + if (args.helpRequested) { std::vector subcommand; MultiCommand * command = &args; while (command) { @@ -349,8 +352,6 @@ void mainWrapped(int argc, char * * argv) } showHelp(subcommand, args); return; - } catch (UsageError &) { - if (!completions) throw; } if (completions) {