lix/src/libmain/shared.cc
2020-05-03 08:01:25 -06:00

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#include "globals.hh"
#include "shared.hh"
#include "store-api.hh"
#include "util.hh"
#include <algorithm>
#include <cctype>
#include <exception>
#include <iostream>
#include <mutex>
#include <cstdlib>
#include <sys/time.h>
#include <sys/stat.h>
#include <unistd.h>
#include <signal.h>
#include <openssl/crypto.h>
namespace nix {
static bool gcWarning = true;
void printGCWarning()
{
if (!gcWarning) return;
static bool haveWarned = false;
warnOnce(haveWarned,
"you did not specify '--add-root'; "
"the result might be removed by the garbage collector");
}
void printMissing(ref<Store> store, const std::vector<StorePathWithOutputs> & paths, Verbosity lvl)
{
unsigned long long downloadSize, narSize;
StorePathSet willBuild, willSubstitute, unknown;
store->queryMissing(paths, willBuild, willSubstitute, unknown, downloadSize, narSize);
printMissing(store, willBuild, willSubstitute, unknown, downloadSize, narSize, lvl);
}
void printMissing(ref<Store> store, const StorePathSet & willBuild,
const StorePathSet & willSubstitute, const StorePathSet & unknown,
unsigned long long downloadSize, unsigned long long narSize, Verbosity lvl)
{
if (!willBuild.empty()) {
printMsg(lvl, "these derivations will be built:");
auto sorted = store->topoSortPaths(willBuild);
reverse(sorted.begin(), sorted.end());
for (auto & i : sorted)
printMsg(lvl, fmt(" %s", store->printStorePath(i)));
}
if (!willSubstitute.empty()) {
printMsg(lvl, fmt("these paths will be fetched (%.2f MiB download, %.2f MiB unpacked):",
downloadSize / (1024.0 * 1024.0),
narSize / (1024.0 * 1024.0)));
for (auto & i : willSubstitute)
printMsg(lvl, fmt(" %s", store->printStorePath(i)));
}
if (!unknown.empty()) {
printMsg(lvl, fmt("don't know how to build these paths%s:",
(settings.readOnlyMode ? " (may be caused by read-only store access)" : "")));
for (auto & i : unknown)
printMsg(lvl, fmt(" %s", store->printStorePath(i)));
}
}
string getArg(const string & opt,
Strings::iterator & i, const Strings::iterator & end)
{
++i;
if (i == end) throw UsageError("'%1%' requires an argument", opt);
return *i;
}
#if OPENSSL_VERSION_NUMBER < 0x10101000L
/* OpenSSL is not thread-safe by default - it will randomly crash
unless the user supplies a mutex locking function. So let's do
that. */
static std::vector<std::mutex> opensslLocks;
static void opensslLockCallback(int mode, int type, const char * file, int line)
{
if (mode & CRYPTO_LOCK)
opensslLocks[type].lock();
else
opensslLocks[type].unlock();
}
#endif
static void sigHandler(int signo) { }
void initNix()
{
/* Turn on buffering for cerr. */
#if HAVE_PUBSETBUF
static char buf[1024];
std::cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));
#endif
#if OPENSSL_VERSION_NUMBER < 0x10101000L
/* Initialise OpenSSL locking. */
opensslLocks = std::vector<std::mutex>(CRYPTO_num_locks());
CRYPTO_set_locking_callback(opensslLockCallback);
#endif
loadConfFile();
startSignalHandlerThread();
/* Reset SIGCHLD to its default. */
struct sigaction act;
sigemptyset(&act.sa_mask);
act.sa_handler = SIG_DFL;
act.sa_flags = 0;
if (sigaction(SIGCHLD, &act, 0))
throw SysError("resetting SIGCHLD");
/* Install a dummy SIGUSR1 handler for use with pthread_kill(). */
act.sa_handler = sigHandler;
if (sigaction(SIGUSR1, &act, 0)) throw SysError("handling SIGUSR1");
#if __APPLE__
/* HACK: on darwin, we need cant use sigprocmask with SIGWINCH.
* Instead, add a dummy sigaction handler, and signalHandlerThread
* can handle the rest. */
struct sigaction sa;
sa.sa_handler = sigHandler;
if (sigaction(SIGWINCH, &sa, 0)) throw SysError("handling SIGWINCH");
#endif
/* Register a SIGSEGV handler to detect stack overflows. */
detectStackOverflow();
/* There is no privacy in the Nix system ;-) At least not for
now. In particular, store objects should be readable by
everybody. */
umask(0022);
/* Initialise the PRNG. */
struct timeval tv;
gettimeofday(&tv, 0);
srandom(tv.tv_usec);
/* On macOS, don't use the per-session TMPDIR (as set e.g. by
sshd). This breaks build users because they don't have access
to the TMPDIR, in particular in nix-store --serve. */
#if __APPLE__
if (getuid() == 0 && hasPrefix(getEnv("TMPDIR").value_or("/tmp"), "/var/folders/"))
unsetenv("TMPDIR");
#endif
}
LegacyArgs::LegacyArgs(const std::string & programName,
std::function<bool(Strings::iterator & arg, const Strings::iterator & end)> parseArg)
: MixCommonArgs(programName), parseArg(parseArg)
{
mkFlag()
.longName("no-build-output")
.shortName('Q')
.description("do not show build output")
.set(&settings.verboseBuild, false);
mkFlag()
.longName("keep-failed")
.shortName('K')
.description("keep temporary directories of failed builds")
.set(&(bool&) settings.keepFailed, true);
mkFlag()
.longName("keep-going")
.shortName('k')
.description("keep going after a build fails")
.set(&(bool&) settings.keepGoing, true);
mkFlag()
.longName("fallback")
.description("build from source if substitution fails")
.set(&(bool&) settings.tryFallback, true);
auto intSettingAlias = [&](char shortName, const std::string & longName,
const std::string & description, const std::string & dest) {
mkFlag<unsigned int>(shortName, longName, description, [=](unsigned int n) {
settings.set(dest, std::to_string(n));
});
};
intSettingAlias(0, "cores", "maximum number of CPU cores to use inside a build", "cores");
intSettingAlias(0, "max-silent-time", "number of seconds of silence before a build is killed", "max-silent-time");
intSettingAlias(0, "timeout", "number of seconds before a build is killed", "timeout");
mkFlag(0, "readonly-mode", "do not write to the Nix store",
&settings.readOnlyMode);
mkFlag(0, "no-gc-warning", "disable warning about not using '--add-root'",
&gcWarning, false);
mkFlag()
.longName("store")
.label("store-uri")
.description("URI of the Nix store to use")
.dest(&(std::string&) settings.storeUri);
}
bool LegacyArgs::processFlag(Strings::iterator & pos, Strings::iterator end)
{
if (MixCommonArgs::processFlag(pos, end)) return true;
bool res = parseArg(pos, end);
if (res) ++pos;
return res;
}
bool LegacyArgs::processArgs(const Strings & args, bool finish)
{
if (args.empty()) return true;
assert(args.size() == 1);
Strings ss(args);
auto pos = ss.begin();
if (!parseArg(pos, ss.end()))
throw UsageError("unexpected argument '%1%'", args.front());
return true;
}
void parseCmdLine(int argc, char * * argv,
std::function<bool(Strings::iterator & arg, const Strings::iterator & end)> parseArg)
{
parseCmdLine(std::string(baseNameOf(argv[0])), argvToStrings(argc, argv), parseArg);
}
void parseCmdLine(const string & programName, const Strings & args,
std::function<bool(Strings::iterator & arg, const Strings::iterator & end)> parseArg)
{
LegacyArgs(programName, parseArg).parseCmdline(args);
}
void printVersion(const string & programName)
{
std::cout << format("%1% (Nix) %2%") % programName % nixVersion << std::endl;
if (verbosity > lvlInfo) {
Strings cfg;
#if HAVE_BOEHMGC
cfg.push_back("gc");
#endif
#if HAVE_SODIUM
cfg.push_back("signed-caches");
#endif
std::cout << "Features: " << concatStringsSep(", ", cfg) << "\n";
std::cout << "Configuration file: " << settings.nixConfDir + "/nix.conf" << "\n";
std::cout << "Store directory: " << settings.nixStore << "\n";
std::cout << "State directory: " << settings.nixStateDir << "\n";
}
throw Exit();
}
void showManPage(const string & name)
{
restoreSignals();
setenv("MANPATH", settings.nixManDir.c_str(), 1);
execlp("man", "man", name.c_str(), nullptr);
throw SysError("command 'man %1%' failed", name.c_str());
}
int handleExceptions(const string & programName, std::function<void()> fun)
{
ReceiveInterrupts receiveInterrupts; // FIXME: need better place for this
ErrorInfo::programName = programName;
string error = ANSI_RED "error:" ANSI_NORMAL " ";
try {
try {
fun();
} catch (...) {
/* Subtle: we have to make sure that any `interrupted'
condition is discharged before we reach printMsg()
below, since otherwise it will throw an (uncaught)
exception. */
setInterruptThrown();
throw;
}
} catch (Exit & e) {
return e.status;
} catch (UsageError & e) {
// TODO: switch to logError
// logError(e.info());
_printError(
format("%1%\nTry '%2% --help' for more information.")
% e.what() % programName);
return 1;
} catch (BaseError & e) {
// logError(e.info());
_printError("%1%%2%", (settings.showTrace ? e.prefix() : ""), e.msg());
if (e.prefix() != "" && !settings.showTrace)
_printError("(use '--show-trace' to show detailed location information)");
return e.status;
} catch (std::bad_alloc & e) {
_printError(error + "out of memory");
return 1;
} catch (std::exception & e) {
_printError(error + e.what());
return 1;
}
return 0;
}
RunPager::RunPager()
{
if (!isatty(STDOUT_FILENO)) return;
char * pager = getenv("NIX_PAGER");
if (!pager) pager = getenv("PAGER");
if (pager && ((string) pager == "" || (string) pager == "cat")) return;
Pipe toPager;
toPager.create();
pid = startProcess([&]() {
if (dup2(toPager.readSide.get(), STDIN_FILENO) == -1)
throw SysError("dupping stdin");
if (!getenv("LESS"))
setenv("LESS", "FRSXMK", 1);
restoreSignals();
if (pager)
execl("/bin/sh", "sh", "-c", pager, nullptr);
execlp("pager", "pager", nullptr);
execlp("less", "less", nullptr);
execlp("more", "more", nullptr);
throw SysError("executing '%1%'", pager);
});
pid.setKillSignal(SIGINT);
if (dup2(toPager.writeSide.get(), STDOUT_FILENO) == -1)
throw SysError("dupping stdout");
}
RunPager::~RunPager()
{
try {
if (pid != -1) {
std::cout.flush();
close(STDOUT_FILENO);
pid.wait();
}
} catch (...) {
ignoreException();
}
}
string showBytes(unsigned long long bytes)
{
return (format("%.2f MiB") % (bytes / (1024.0 * 1024.0))).str();
}
PrintFreed::~PrintFreed()
{
if (show)
std::cout << format("%1% store paths deleted, %2% freed\n")
% results.paths.size()
% showBytes(results.bytesFreed);
}
Exit::~Exit() { }
}