From 0db9e6cd1af299f7d65e0b99019f0ccdbb1aaf3f Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Tue, 9 Feb 2016 21:07:48 +0100 Subject: New command line parsing infrastructure --- src/libmain/common-args.cc | 37 ++++++++++ src/libmain/common-args.hh | 22 ++++++ src/libmain/shared.cc | 148 ++++++++++++++++++------------------- src/libmain/shared.hh | 3 +- src/libutil/args.cc | 179 +++++++++++++++++++++++++++++++++++++++++++++ src/libutil/args.hh | 160 ++++++++++++++++++++++++++++++++++++++++ 6 files changed, 470 insertions(+), 79 deletions(-) create mode 100644 src/libmain/common-args.cc create mode 100644 src/libmain/common-args.hh create mode 100644 src/libutil/args.cc create mode 100644 src/libutil/args.hh diff --git a/src/libmain/common-args.cc b/src/libmain/common-args.cc new file mode 100644 index 000000000000..54dbb1da3ca8 --- /dev/null +++ b/src/libmain/common-args.cc @@ -0,0 +1,37 @@ +#include "common-args.hh" +#include "globals.hh" + +namespace nix { + +MixCommonArgs::MixCommonArgs(const string & programName) +{ + mkFlag('v', "verbose", "increase verbosity level", []() { + verbosity = (Verbosity) (verbosity + 1); + }); + + mkFlag(0, "quiet", "decrease verbosity level", []() { + verbosity = verbosity > lvlError ? (Verbosity) (verbosity - 1) : lvlError; + }); + + mkFlag(0, "debug", "enable debug output", []() { + verbosity = lvlDebug; + }); + + mkFlag1(0, "log-type", "type", "set logging format ('pretty', 'flat', 'systemd')", + [](std::string s) { + if (s == "pretty") logType = ltPretty; + else if (s == "escapes") logType = ltEscapes; + else if (s == "flat") logType = ltFlat; + else if (s == "systemd") logType = ltSystemd; + else throw UsageError("unknown log type"); + }); + + mkFlag(0, "option", {"name", "value"}, "set a Nix configuration option (overriding nix.conf)", 2, + [](Strings ss) { + auto name = ss.front(); ss.pop_front(); + auto value = ss.front(); + settings.set(name, value); + }); +} + +} diff --git a/src/libmain/common-args.hh b/src/libmain/common-args.hh new file mode 100644 index 000000000000..62657e0d0218 --- /dev/null +++ b/src/libmain/common-args.hh @@ -0,0 +1,22 @@ +#pragma once + +#include "args.hh" + +namespace nix { + +struct MixCommonArgs : virtual Args +{ + MixCommonArgs(const string & programName); +}; + +struct MixDryRun : virtual Args +{ + bool dryRun; + + MixDryRun() + { + mkFlag(0, "dry-run", "show what this command would do without doing it", &dryRun); + } +}; + +} diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index 88ed52497fb9..bf6bf5b712e7 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -1,7 +1,8 @@ #include "config.h" -#include "shared.hh" +#include "common-args.hh" #include "globals.hh" +#include "shared.hh" #include "store-api.hh" #include "util.hh" @@ -84,16 +85,6 @@ void printMissing(ref store, const PathSet & willBuild, } -static void setLogType(string lt) -{ - if (lt == "pretty") logType = ltPretty; - else if (lt == "escapes") logType = ltEscapes; - else if (lt == "flat") logType = ltFlat; - else if (lt == "systemd") logType = ltSystemd; - else throw UsageError("unknown log type"); -} - - string getArg(const string & opt, Strings::iterator & i, const Strings::iterator & end) { @@ -164,77 +155,80 @@ void initNix() } -void parseCmdLine(int argc, char * * argv, - std::function parseArg) +struct LegacyArgs : public MixCommonArgs { - /* Put the arguments in a vector. */ - Strings args; - argc--; argv++; - while (argc--) args.push_back(*argv++); - - /* Process default options. */ - for (Strings::iterator i = args.begin(); i != args.end(); ++i) { - string arg = *i; - - /* Expand compound dash options (i.e., `-qlf' -> `-q -l -f'). */ - if (arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && isalpha(arg[1])) { - *i = (string) "-" + arg[1]; - auto next = i; ++next; - for (unsigned int j = 2; j < arg.length(); j++) - if (isalpha(arg[j])) - args.insert(next, (string) "-" + arg[j]); - else { - args.insert(next, string(arg, j)); - break; - } - arg = *i; - } + std::function parseArg; - if (arg == "--verbose" || arg == "-v") verbosity = (Verbosity) (verbosity + 1); - else if (arg == "--quiet") verbosity = verbosity > lvlError ? (Verbosity) (verbosity - 1) : lvlError; - else if (arg == "--log-type") { - string s = getArg(arg, i, args.end()); - setLogType(s); - } - else if (arg == "--no-build-output" || arg == "-Q") - settings.buildVerbosity = lvlVomit; - else if (arg == "--print-build-trace") - settings.printBuildTrace = true; - else if (arg == "--keep-failed" || arg == "-K") - settings.keepFailed = true; - else if (arg == "--keep-going" || arg == "-k") - settings.keepGoing = true; - else if (arg == "--fallback") + LegacyArgs(const std::string & programName, + std::function parseArg) + : MixCommonArgs(programName), parseArg(parseArg) + { + mkFlag('Q', "no-build-output", "do not show build output", + &settings.buildVerbosity, lvlVomit); + + mkFlag(0, "print-build-trace", "emit special build trace message", + &settings.printBuildTrace); + + mkFlag('K', "keep-failed", "keep temporary directories of failed builds", + &settings.keepFailed); + + mkFlag('k', "keep-going", "keep going after a build fails", + &settings.keepGoing); + + mkFlag(0, "fallback", "build from source if substitution fails", []() { settings.set("build-fallback", "true"); - else if (arg == "--max-jobs" || arg == "-j") - settings.set("build-max-jobs", getArg(arg, i, args.end())); - else if (arg == "--cores") - settings.set("build-cores", getArg(arg, i, args.end())); - else if (arg == "--readonly-mode") - settings.readOnlyMode = true; - else if (arg == "--max-silent-time") - settings.set("build-max-silent-time", getArg(arg, i, args.end())); - else if (arg == "--timeout") - settings.set("build-timeout", getArg(arg, i, args.end())); - else if (arg == "--no-build-hook") - settings.useBuildHook = false; - else if (arg == "--show-trace") - settings.showTrace = true; - else if (arg == "--no-gc-warning") - gcWarning = false; - else if (arg == "--option") { - ++i; if (i == args.end()) throw UsageError("‘--option’ requires two arguments"); - string name = *i; - ++i; if (i == args.end()) throw UsageError("‘--option’ requires two arguments"); - string value = *i; - settings.set(name, value); - } - else { - if (!parseArg(i, args.end())) - throw UsageError(format("unrecognised option ‘%1%’") % *i); - } + }); + + auto intSettingAlias = [&](char shortName, const std::string & longName, + const std::string & description, const std::string & dest) { + mkFlag(shortName, longName, description, [=](unsigned int n) { + settings.set(dest, std::to_string(n)); + }); + }; + + intSettingAlias('j', "max-jobs", "maximum number of parallel builds", "build-max-jobs"); + intSettingAlias(0, "cores", "maximum number of CPU cores to use inside a build", "build-cores"); + intSettingAlias(0, "max-silent-time", "number of seconds of silence before a build is killed", "build-max-silent-time"); + intSettingAlias(0, "timeout", "number of seconds before a build is killed", "build-timeout"); + + mkFlag(0, "readonly-mode", "do not write to the Nix store", + &settings.readOnlyMode); + + mkFlag(0, "no-build-hook", "disable use of the build hook mechanism", + &settings.useBuildHook, false); + + mkFlag(0, "show-trace", "show Nix expression stack trace in evaluation errors", + &settings.showTrace); + + mkFlag(0, "no-gc-warning", "disable warning about not using ‘--add-root’", + &gcWarning, false); } + bool processFlag(Strings::iterator & pos, Strings::iterator end) override + { + if (MixCommonArgs::processFlag(pos, end)) return true; + bool res = parseArg(pos, end); + if (res) ++pos; + return res; + } + + bool processArgs(const Strings & args, bool finish) override + { + if (args.empty()) return true; + assert(args.size() == 1); + Strings ss(args); + auto pos = ss.begin(); + if (!parseArg(pos, ss.end())) + throw UsageError(format("unexpected argument ‘%1%’") % args.front()); + return true; + } +}; + + +void parseCmdLine(int argc, char * * argv, + std::function parseArg) +{ + LegacyArgs(baseNameOf(argv[0]), parseArg).parseCmdline(argvToStrings(argc, argv)); settings.update(); } diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh index e4b984f067e4..20744be0ab9b 100644 --- a/src/libmain/shared.hh +++ b/src/libmain/shared.hh @@ -1,6 +1,7 @@ #pragma once #include "util.hh" +#include "args.hh" #include @@ -9,8 +10,6 @@ namespace nix { -MakeError(UsageError, nix::Error); - class Exit : public std::exception { public: diff --git a/src/libutil/args.cc b/src/libutil/args.cc new file mode 100644 index 000000000000..6e4b82a279ce --- /dev/null +++ b/src/libutil/args.cc @@ -0,0 +1,179 @@ +#include "args.hh" +#include "hash.hh" + +namespace nix { + +void Args::parseCmdline(const Strings & _cmdline) +{ + Strings pendingArgs; + bool dashDash = false; + + Strings cmdline(_cmdline); + + for (auto pos = cmdline.begin(); pos != cmdline.end(); ) { + + auto arg = *pos; + + /* Expand compound dash options (i.e., `-qlf' -> `-q -l -f', + `-j3` -> `-j 3`). */ + if (!dashDash && arg.length() > 2 && arg[0] == '-' && arg[1] != '-' && isalpha(arg[1])) { + *pos = (string) "-" + arg[1]; + auto next = pos; ++next; + for (unsigned int j = 2; j < arg.length(); j++) + if (isalpha(arg[j])) + cmdline.insert(next, (string) "-" + arg[j]); + else { + cmdline.insert(next, string(arg, j)); + break; + } + arg = *pos; + } + + if (!dashDash && arg == "--") { + dashDash = true; + ++pos; + } + else if (!dashDash && std::string(arg, 0, 1) == "-") { + if (!processFlag(pos, cmdline.end())) + throw UsageError(format("unrecognised flag ‘%1%’") % arg); + } + else { + pendingArgs.push_back(*pos++); + if (processArgs(pendingArgs, false)) + pendingArgs.clear(); + } + } + + processArgs(pendingArgs, true); +} + +void Args::printHelp(const string & programName, std::ostream & out) +{ + std::cout << "Usage: " << programName << " ..."; + for (auto & exp : expectedArgs) { + std::cout << renderLabels({exp.label}); + // FIXME: handle arity > 1 + if (exp.arity == 0) std::cout << "..."; + } + std::cout << "\n"; + + auto s = description(); + if (s != "") + std::cout << "\nSummary: " << s << ".\n"; + + if (longFlags.size()) { + std::cout << "\n"; + std::cout << "Flags:\n"; + printFlags(out); + } +} + +void Args::printFlags(std::ostream & out) +{ + Table2 table; + for (auto & flags : longFlags) + table.push_back(std::make_pair( + "--" + flags.first + renderLabels(flags.second.labels), + flags.second.description)); + printTable(out, table); +} + +bool Args::processFlag(Strings::iterator & pos, Strings::iterator end) +{ + assert(pos != end); + + auto process = [&](const std::string & name, const Flag & flag) -> bool { + ++pos; + Strings args; + for (size_t n = 0 ; n < flag.arity; ++n) { + if (pos == end) + throw UsageError(format("flag ‘%1%’ requires %2% argument(s)") + % name % flag.arity); + args.push_back(*pos++); + } + flag.handler(args); + return true; + }; + + if (string(*pos, 0, 2) == "--") { + auto i = longFlags.find(string(*pos, 2)); + if (i == longFlags.end()) return false; + return process("--" + i->first, i->second); + } + + if (string(*pos, 0, 1) == "-" && pos->size() == 2) { + auto c = (*pos)[1]; + auto i = shortFlags.find(c); + if (i == shortFlags.end()) return false; + return process(std::string("-") + c, i->second); + } + + return false; +} + +bool Args::processArgs(const Strings & args, bool finish) +{ + if (expectedArgs.empty()) { + if (!args.empty()) + throw UsageError(format("unexpected argument ‘%1%’") % args.front()); + return true; + } + + auto & exp = expectedArgs.front(); + + bool res = false; + + if ((exp.arity == 0 && finish) || + (exp.arity > 0 && args.size() == exp.arity)) + { + exp.handler(args); + expectedArgs.pop_front(); + res = true; + } + + if (finish && !expectedArgs.empty()) + throw UsageError("more arguments are required"); + + return res; +} + +void Args::mkHashTypeFlag(const std::string & name, HashType * ht) +{ + mkFlag1(0, name, "TYPE", "hash algorithm (‘md5’, ‘sha1’, ‘sha256’, or ‘sha512’)", [=](std::string s) { + *ht = parseHashType(s); + if (*ht == htUnknown) + throw UsageError(format("unknown hash type ‘%1%’") % s); + }); +} + +Strings argvToStrings(int argc, char * * argv) +{ + Strings args; + argc--; argv++; + while (argc--) args.push_back(*argv++); + return args; +} + +std::string renderLabels(const Strings & labels) +{ + std::string res; + for (auto label : labels) { + for (auto & c : label) c = std::toupper(c); + res += " <" + label + ">"; + } + return res; +} + +void printTable(std::ostream & out, const Table2 & table) +{ + size_t max = 0; + for (auto & row : table) + max = std::max(max, row.first.size()); + for (auto & row : table) { + out << " " << row.first + << std::string(max - row.first.size() + 2, ' ') + << row.second << "\n"; + } +} + +} diff --git a/src/libutil/args.hh b/src/libutil/args.hh new file mode 100644 index 000000000000..c61a2b02a7ac --- /dev/null +++ b/src/libutil/args.hh @@ -0,0 +1,160 @@ +#pragma once + +#include +#include +#include + +#include "util.hh" + +namespace nix { + +MakeError(UsageError, nix::Error); + +enum HashType : char; + +class Args +{ +public: + + /* Parse the command line, throwing a UsageError if something goes + wrong. */ + void parseCmdline(const Strings & cmdline); + + virtual void printHelp(const string & programName, std::ostream & out); + + virtual std::string description() { return ""; } + +protected: + + /* Flags. */ + struct Flag + { + std::string description; + Strings labels; + size_t arity; + std::function handler; + }; + + std::map longFlags; + std::map shortFlags; + + virtual bool processFlag(Strings::iterator & pos, Strings::iterator end); + + void printFlags(std::ostream & out); + + /* Positional arguments. */ + struct ExpectedArg + { + std::string label; + size_t arity; // 0 = any + std::function handler; + }; + + std::list expectedArgs; + + virtual bool processArgs(const Strings & args, bool finish); + +public: + + /* Helper functions for constructing flags / positional + arguments. */ + + void mkFlag(char shortName, const std::string & longName, + const Strings & labels, const std::string & description, + size_t arity, std::function handler) + { + auto flag = Flag{description, labels, arity, handler}; + if (shortName) shortFlags[shortName] = flag; + longFlags[longName] = flag; + } + + void mkFlag(char shortName, const std::string & longName, + const std::string & description, std::function fun) + { + mkFlag(shortName, longName, {}, description, 0, std::bind(fun)); + } + + void mkFlag1(char shortName, const std::string & longName, + const std::string & label, const std::string & description, + std::function fun) + { + mkFlag(shortName, longName, {label}, description, 1, [=](Strings ss) { + fun(ss.front()); + }); + } + + void mkFlag(char shortName, const std::string & name, + const std::string & description, bool * dest) + { + mkFlag(0, name, description, dest, true); + } + + void mkFlag(char shortName, const std::string & longName, + const std::string & label, const std::string & description, + string * dest) + { + mkFlag1(shortName, longName, label, description, [=](std::string s) { + *dest = s; + }); + } + + void mkHashTypeFlag(const std::string & name, HashType * ht); + + template + void mkFlag(char shortName, const std::string & longName, const std::string & description, + T * dest, const T & value) + { + mkFlag(shortName, longName, {}, description, 0, [=](Strings ss) { + *dest = value; + }); + } + + template + void mkIntFlag(char shortName, const std::string & longName, + const std::string & description, I * dest) + { + mkFlag(shortName, longName, description, [=](I n) { + *dest = n; + }); + } + + template + void mkFlag(char shortName, const std::string & longName, + const std::string & description, std::function fun) + { + mkFlag(shortName, longName, {"N"}, description, 1, [=](Strings ss) { + I n; + if (!string2Int(ss.front(), n)) + throw UsageError(format("flag ‘--%1%’ requires a integer argument") % longName); + fun(n); + }); + } + + /* Expect a string argument. */ + void expectArg(const std::string & label, string * dest) + { + expectedArgs.push_back(ExpectedArg{label, 1, [=](Strings ss) { + *dest = ss.front(); + }}); + } + + /* Expect 0 or more arguments. */ + void expectArgs(const std::string & label, Strings * dest) + { + expectedArgs.push_back(ExpectedArg{label, 0, [=](Strings ss) { + *dest = ss; + }}); + } +}; + +Strings argvToStrings(int argc, char * * argv); + +/* Helper function for rendering argument labels. */ +std::string renderLabels(const Strings & labels); + +/* Helper function for printing 2-column tables. */ +typedef std::vector> Table2; + +void printTable(std::ostream & out, const Table2 & table); + +} -- cgit 1.4.1