lix/src/nix/main.cc
Eelco Dolstra 737ed88f35
Modularize config settings
Allow global config settings to be defined in multiple Config
classes. For example, this means that libutil can have settings and
evaluator settings can be moved out of libstore. The Config classes
are registered in a new GlobalConfig class to which config files
etc. are applied.

Relevant to https://github.com/NixOS/nix/issues/2009 in that it
removes the need for ad hoc handling of useCaseHack, which was the
underlying cause of that issue.
2018-05-30 13:28:01 +02:00

116 lines
2.9 KiB
C++

#include <algorithm>
#include "command.hh"
#include "common-args.hh"
#include "eval.hh"
#include "globals.hh"
#include "legacy.hh"
#include "shared.hh"
#include "store-api.hh"
#include "progress-bar.hh"
#include "finally.hh"
extern std::string chrootHelperName;
void chrootHelper(int argc, char * * argv);
namespace nix {
std::string programPath;
struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
{
NixArgs() : MultiCommand(*RegisterCommand::commands), MixCommonArgs("nix")
{
mkFlag()
.longName("help")
.shortName('h')
.description("show usage information")
.handler([&]() { showHelpAndExit(); });
mkFlag()
.longName("help-config")
.description("show configuration options")
.handler([&]() {
std::cout << "The following configuration options are available:\n\n";
Table2 tbl;
std::map<std::string, Config::SettingInfo> settings;
globalConfig.getSettings(settings);
for (const auto & s : settings)
tbl.emplace_back(s.first, s.second.description);
printTable(std::cout, tbl);
throw Exit();
});
mkFlag()
.longName("version")
.description("show version information")
.handler([&]() { printVersion(programName); });
}
void printFlags(std::ostream & out) override
{
Args::printFlags(out);
std::cout <<
"\n"
"In addition, most configuration settings can be overriden using '--<name> <value>'.\n"
"Boolean settings can be overriden using '--<name>' or '--no-<name>'. See 'nix\n"
"--help-config' for a list of configuration settings.\n";
}
void showHelpAndExit()
{
printHelp(programName, std::cout);
std::cout << "\nNote: this program is EXPERIMENTAL and subject to change.\n";
throw Exit();
}
};
void mainWrapped(int argc, char * * argv)
{
verbosity = lvlError;
settings.verboseBuild = false;
/* The chroot helper needs to be run before any threads have been
started. */
if (argc > 0 && argv[0] == chrootHelperName) {
chrootHelper(argc, argv);
return;
}
initNix();
initGC();
programPath = argv[0];
string programName = baseNameOf(programPath);
{
auto legacy = (*RegisterLegacyCommand::commands)[programName];
if (legacy) return legacy(argc, argv);
}
NixArgs args;
args.parseCmdline(argvToStrings(argc, argv));
initPlugins();
if (!args.command) args.showHelpAndExit();
Finally f([]() { stopProgressBar(); });
if (isatty(STDERR_FILENO))
startProgressBar();
args.command->prepare();
args.command->run();
}
}
int main(int argc, char * * argv)
{
return nix::handleExceptions(argv[0], [&]() {
nix::mainWrapped(argc, argv);
});
}