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authorLudovic Courtès <ludo@gnu.org>2014-12-17 23:00:42 +0100
committerLudovic Courtès <ludo@gnu.org>2014-12-19 22:47:37 +0100
commit36457566f9917dc7c0c348d012816a2ca333ef1b (patch)
tree6f1d22a195ea2483b9ce539227d65e8e2a9c137d /nix/libstore/build.cc
parent2c7ee1672029aa43afb509af5b5f7261244fa2d1 (diff)
downloadguix-36457566f9917dc7c0c348d012816a2ca333ef1b.tar
guix-36457566f9917dc7c0c348d012816a2ca333ef1b.tar.gz
Merge branch 'nix' into 'master'.
Diffstat (limited to 'nix/libstore/build.cc')
-rw-r--r--nix/libstore/build.cc3351
1 files changed, 3351 insertions, 0 deletions
diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
new file mode 100644
index 0000000000..2e2f92fadf
--- /dev/null
+++ b/nix/libstore/build.cc
@@ -0,0 +1,3351 @@
+#include "config.h"
+
+#include "references.hh"
+#include "pathlocks.hh"
+#include "misc.hh"
+#include "globals.hh"
+#include "local-store.hh"
+#include "util.hh"
+#include "archive.hh"
+#include "affinity.hh"
+
+#include <map>
+#include <sstream>
+#include <algorithm>
+
+#include <time.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <cstring>
+
+#include <pwd.h>
+#include <grp.h>
+
+#include <bzlib.h>
+
+/* Includes required for chroot support. */
+#if HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+#if HAVE_SYS_MOUNT_H
+#include <sys/mount.h>
+#endif
+#if HAVE_SCHED_H
+#include <sched.h>
+#endif
+
+/* In GNU libc 2.11, <sys/mount.h> does not define `MS_PRIVATE', but
+ <linux/fs.h> does. */
+#if !defined MS_PRIVATE && defined HAVE_LINUX_FS_H
+#include <linux/fs.h>
+#endif
+
+#define CHROOT_ENABLED HAVE_CHROOT && HAVE_UNSHARE && HAVE_SYS_MOUNT_H && defined(MS_BIND) && defined(MS_PRIVATE) && defined(CLONE_NEWNS)
+
+#if CHROOT_ENABLED
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <netinet/ip.h>
+#endif
+
+#if HAVE_SYS_PERSONALITY_H
+#include <sys/personality.h>
+#define CAN_DO_LINUX32_BUILDS
+#endif
+
+#if HAVE_STATVFS
+#include <sys/statvfs.h>
+#endif
+
+
+namespace nix {
+
+using std::map;
+
+
+static string pathNullDevice = "/dev/null";
+
+
+/* Forward definition. */
+class Worker;
+struct HookInstance;
+
+
+/* A pointer to a goal. */
+class Goal;
+typedef std::shared_ptr<Goal> GoalPtr;
+typedef std::weak_ptr<Goal> WeakGoalPtr;
+
+/* Set of goals. */
+typedef set<GoalPtr> Goals;
+typedef list<WeakGoalPtr> WeakGoals;
+
+/* A map of paths to goals (and the other way around). */
+typedef map<Path, WeakGoalPtr> WeakGoalMap;
+
+
+
+class Goal : public std::enable_shared_from_this<Goal>
+{
+public:
+ typedef enum {ecBusy, ecSuccess, ecFailed, ecNoSubstituters, ecIncompleteClosure} ExitCode;
+
+protected:
+
+ /* Backlink to the worker. */
+ Worker & worker;
+
+ /* Goals that this goal is waiting for. */
+ Goals waitees;
+
+ /* Goals waiting for this one to finish. Must use weak pointers
+ here to prevent cycles. */
+ WeakGoals waiters;
+
+ /* Number of goals we are/were waiting for that have failed. */
+ unsigned int nrFailed;
+
+ /* Number of substitution goals we are/were waiting for that
+ failed because there are no substituters. */
+ unsigned int nrNoSubstituters;
+
+ /* Number of substitution goals we are/were waiting for that
+ failed because othey had unsubstitutable references. */
+ unsigned int nrIncompleteClosure;
+
+ /* Name of this goal for debugging purposes. */
+ string name;
+
+ /* Whether the goal is finished. */
+ ExitCode exitCode;
+
+ Goal(Worker & worker) : worker(worker)
+ {
+ nrFailed = nrNoSubstituters = nrIncompleteClosure = 0;
+ exitCode = ecBusy;
+ }
+
+ virtual ~Goal()
+ {
+ trace("goal destroyed");
+ }
+
+public:
+ virtual void work() = 0;
+
+ void addWaitee(GoalPtr waitee);
+
+ virtual void waiteeDone(GoalPtr waitee, ExitCode result);
+
+ virtual void handleChildOutput(int fd, const string & data)
+ {
+ abort();
+ }
+
+ virtual void handleEOF(int fd)
+ {
+ abort();
+ }
+
+ void trace(const format & f);
+
+ string getName()
+ {
+ return name;
+ }
+
+ ExitCode getExitCode()
+ {
+ return exitCode;
+ }
+
+ /* Cancel the goal. It should wake up its waiters, get rid of any
+ running child processes that are being monitored by the worker
+ (important!), etc. */
+ virtual void cancel(bool timeout) = 0;
+
+protected:
+ void amDone(ExitCode result);
+};
+
+
+/* A mapping used to remember for each child process to what goal it
+ belongs, and file descriptors for receiving log data and output
+ path creation commands. */
+struct Child
+{
+ WeakGoalPtr goal;
+ set<int> fds;
+ bool respectTimeouts;
+ bool inBuildSlot;
+ time_t lastOutput; /* time we last got output on stdout/stderr */
+ time_t timeStarted;
+};
+
+typedef map<pid_t, Child> Children;
+
+
+/* The worker class. */
+class Worker
+{
+private:
+
+ /* Note: the worker should only have strong pointers to the
+ top-level goals. */
+
+ /* The top-level goals of the worker. */
+ Goals topGoals;
+
+ /* Goals that are ready to do some work. */
+ WeakGoals awake;
+
+ /* Goals waiting for a build slot. */
+ WeakGoals wantingToBuild;
+
+ /* Child processes currently running. */
+ Children children;
+
+ /* Number of build slots occupied. This includes local builds and
+ substitutions but not remote builds via the build hook. */
+ unsigned int nrLocalBuilds;
+
+ /* Maps used to prevent multiple instantiations of a goal for the
+ same derivation / path. */
+ WeakGoalMap derivationGoals;
+ WeakGoalMap substitutionGoals;
+
+ /* Goals waiting for busy paths to be unlocked. */
+ WeakGoals waitingForAnyGoal;
+
+ /* Goals sleeping for a few seconds (polling a lock). */
+ WeakGoals waitingForAWhile;
+
+ /* Last time the goals in `waitingForAWhile' where woken up. */
+ time_t lastWokenUp;
+
+public:
+
+ /* Set if at least one derivation had a BuildError (i.e. permanent
+ failure). */
+ bool permanentFailure;
+
+ LocalStore & store;
+
+ std::shared_ptr<HookInstance> hook;
+
+ Worker(LocalStore & store);
+ ~Worker();
+
+ /* Make a goal (with caching). */
+ GoalPtr makeDerivationGoal(const Path & drvPath, const StringSet & wantedOutputs, BuildMode buildMode = bmNormal);
+ GoalPtr makeSubstitutionGoal(const Path & storePath, bool repair = false);
+
+ /* Remove a dead goal. */
+ void removeGoal(GoalPtr goal);
+
+ /* Wake up a goal (i.e., there is something for it to do). */
+ void wakeUp(GoalPtr goal);
+
+ /* Return the number of local build and substitution processes
+ currently running (but not remote builds via the build
+ hook). */
+ unsigned int getNrLocalBuilds();
+
+ /* Registers a running child process. `inBuildSlot' means that
+ the process counts towards the jobs limit. */
+ void childStarted(GoalPtr goal, pid_t pid,
+ const set<int> & fds, bool inBuildSlot, bool respectTimeouts);
+
+ /* Unregisters a running child process. `wakeSleepers' should be
+ false if there is no sense in waking up goals that are sleeping
+ because they can't run yet (e.g., there is no free build slot,
+ or the hook would still say `postpone'). */
+ void childTerminated(pid_t pid, bool wakeSleepers = true);
+
+ /* Put `goal' to sleep until a build slot becomes available (which
+ might be right away). */
+ void waitForBuildSlot(GoalPtr goal);
+
+ /* Wait for any goal to finish. Pretty indiscriminate way to
+ wait for some resource that some other goal is holding. */
+ void waitForAnyGoal(GoalPtr goal);
+
+ /* Wait for a few seconds and then retry this goal. Used when
+ waiting for a lock held by another process. This kind of
+ polling is inefficient, but POSIX doesn't really provide a way
+ to wait for multiple locks in the main select() loop. */
+ void waitForAWhile(GoalPtr goal);
+
+ /* Loop until the specified top-level goals have finished. */
+ void run(const Goals & topGoals);
+
+ /* Wait for input to become available. */
+ void waitForInput();
+
+ unsigned int exitStatus();
+};
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+void addToWeakGoals(WeakGoals & goals, GoalPtr p)
+{
+ // FIXME: necessary?
+ foreach (WeakGoals::iterator, i, goals)
+ if (i->lock() == p) return;
+ goals.push_back(p);
+}
+
+
+void Goal::addWaitee(GoalPtr waitee)
+{
+ waitees.insert(waitee);
+ addToWeakGoals(waitee->waiters, shared_from_this());
+}
+
+
+void Goal::waiteeDone(GoalPtr waitee, ExitCode result)
+{
+ assert(waitees.find(waitee) != waitees.end());
+ waitees.erase(waitee);
+
+ trace(format("waitee `%1%' done; %2% left") %
+ waitee->name % waitees.size());
+
+ if (result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure) ++nrFailed;
+
+ if (result == ecNoSubstituters) ++nrNoSubstituters;
+
+ if (result == ecIncompleteClosure) ++nrIncompleteClosure;
+
+ if (waitees.empty() || (result == ecFailed && !settings.keepGoing)) {
+
+ /* If we failed and keepGoing is not set, we remove all
+ remaining waitees. */
+ foreach (Goals::iterator, i, waitees) {
+ GoalPtr goal = *i;
+ WeakGoals waiters2;
+ foreach (WeakGoals::iterator, j, goal->waiters)
+ if (j->lock() != shared_from_this()) waiters2.push_back(*j);
+ goal->waiters = waiters2;
+ }
+ waitees.clear();
+
+ worker.wakeUp(shared_from_this());
+ }
+}
+
+
+void Goal::amDone(ExitCode result)
+{
+ trace("done");
+ assert(exitCode == ecBusy);
+ assert(result == ecSuccess || result == ecFailed || result == ecNoSubstituters || result == ecIncompleteClosure);
+ exitCode = result;
+ foreach (WeakGoals::iterator, i, waiters) {
+ GoalPtr goal = i->lock();
+ if (goal) goal->waiteeDone(shared_from_this(), result);
+ }
+ waiters.clear();
+ worker.removeGoal(shared_from_this());
+}
+
+
+void Goal::trace(const format & f)
+{
+ debug(format("%1%: %2%") % name % f);
+}
+
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+/* Common initialisation performed in child processes. */
+static void commonChildInit(Pipe & logPipe)
+{
+ restoreAffinity();
+
+ /* Put the child in a separate session (and thus a separate
+ process group) so that it has no controlling terminal (meaning
+ that e.g. ssh cannot open /dev/tty) and it doesn't receive
+ terminal signals. */
+ if (setsid() == -1)
+ throw SysError(format("creating a new session"));
+
+ /* Dup the write side of the logger pipe into stderr. */
+ if (dup2(logPipe.writeSide, STDERR_FILENO) == -1)
+ throw SysError("cannot pipe standard error into log file");
+
+ /* Dup stderr to stdout. */
+ if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
+ throw SysError("cannot dup stderr into stdout");
+
+ /* Reroute stdin to /dev/null. */
+ int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
+ if (fdDevNull == -1)
+ throw SysError(format("cannot open `%1%'") % pathNullDevice);
+ if (dup2(fdDevNull, STDIN_FILENO) == -1)
+ throw SysError("cannot dup null device into stdin");
+ close(fdDevNull);
+}
+
+
+/* Convert a string list to an array of char pointers. Careful: the
+ string list should outlive the array. */
+const char * * strings2CharPtrs(const Strings & ss)
+{
+ const char * * arr = new const char * [ss.size() + 1];
+ const char * * p = arr;
+ foreach (Strings::const_iterator, i, ss) *p++ = i->c_str();
+ *p = 0;
+ return arr;
+}
+
+
+/* Restore default handling of SIGPIPE, otherwise some programs will
+ randomly say "Broken pipe". */
+static void restoreSIGPIPE()
+{
+ struct sigaction act, oact;
+ act.sa_handler = SIG_DFL;
+ act.sa_flags = 0;
+ sigemptyset(&act.sa_mask);
+ if (sigaction(SIGPIPE, &act, &oact)) throw SysError("resetting SIGPIPE");
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+class UserLock
+{
+private:
+ /* POSIX locks suck. If we have a lock on a file, and we open and
+ close that file again (without closing the original file
+ descriptor), we lose the lock. So we have to be *very* careful
+ not to open a lock file on which we are holding a lock. */
+ static PathSet lockedPaths; /* !!! not thread-safe */
+
+ Path fnUserLock;
+ AutoCloseFD fdUserLock;
+
+ string user;
+ uid_t uid;
+ gid_t gid;
+
+public:
+ UserLock();
+ ~UserLock();
+
+ void acquire();
+ void release();
+
+ void kill();
+
+ string getUser() { return user; }
+ uid_t getUID() { return uid; }
+ uid_t getGID() { return gid; }
+
+ bool enabled() { return uid != 0; }
+
+};
+
+
+PathSet UserLock::lockedPaths;
+
+
+UserLock::UserLock()
+{
+ uid = gid = 0;
+}
+
+
+UserLock::~UserLock()
+{
+ release();
+}
+
+
+void UserLock::acquire()
+{
+ assert(uid == 0);
+
+ assert(settings.buildUsersGroup != "");
+
+ /* Get the members of the build-users-group. */
+ struct group * gr = getgrnam(settings.buildUsersGroup.c_str());
+ if (!gr)
+ throw Error(format("the group `%1%' specified in `build-users-group' does not exist")
+ % settings.buildUsersGroup);
+ gid = gr->gr_gid;
+
+ /* Copy the result of getgrnam. */
+ Strings users;
+ for (char * * p = gr->gr_mem; *p; ++p) {
+ debug(format("found build user `%1%'") % *p);
+ users.push_back(*p);
+ }
+
+ if (users.empty())
+ throw Error(format("the build users group `%1%' has no members")
+ % settings.buildUsersGroup);
+
+ /* Find a user account that isn't currently in use for another
+ build. */
+ foreach (Strings::iterator, i, users) {
+ debug(format("trying user `%1%'") % *i);
+
+ struct passwd * pw = getpwnam(i->c_str());
+ if (!pw)
+ throw Error(format("the user `%1%' in the group `%2%' does not exist")
+ % *i % settings.buildUsersGroup);
+
+ createDirs(settings.nixStateDir + "/userpool");
+
+ fnUserLock = (format("%1%/userpool/%2%") % settings.nixStateDir % pw->pw_uid).str();
+
+ if (lockedPaths.find(fnUserLock) != lockedPaths.end())
+ /* We already have a lock on this one. */
+ continue;
+
+ AutoCloseFD fd = open(fnUserLock.c_str(), O_RDWR | O_CREAT, 0600);
+ if (fd == -1)
+ throw SysError(format("opening user lock `%1%'") % fnUserLock);
+ closeOnExec(fd);
+
+ if (lockFile(fd, ltWrite, false)) {
+ fdUserLock = fd.borrow();
+ lockedPaths.insert(fnUserLock);
+ user = *i;
+ uid = pw->pw_uid;
+
+ /* Sanity check... */
+ if (uid == getuid() || uid == geteuid())
+ throw Error(format("the Nix user should not be a member of `%1%'")
+ % settings.buildUsersGroup);
+
+ return;
+ }
+ }
+
+ throw Error(format("all build users are currently in use; "
+ "consider creating additional users and adding them to the `%1%' group")
+ % settings.buildUsersGroup);
+}
+
+
+void UserLock::release()
+{
+ if (uid == 0) return;
+ fdUserLock.close(); /* releases lock */
+ assert(lockedPaths.find(fnUserLock) != lockedPaths.end());
+ lockedPaths.erase(fnUserLock);
+ fnUserLock = "";
+ uid = 0;
+}
+
+
+void UserLock::kill()
+{
+ assert(enabled());
+ killUser(uid);
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+struct HookInstance
+{
+ /* Pipes for talking to the build hook. */
+ Pipe toHook;
+
+ /* Pipe for the hook's standard output/error. */
+ Pipe fromHook;
+
+ /* Pipe for the builder's standard output/error. */
+ Pipe builderOut;
+
+ /* The process ID of the hook. */
+ Pid pid;
+
+ HookInstance();
+
+ ~HookInstance();
+};
+
+
+HookInstance::HookInstance()
+{
+ debug("starting build hook");
+
+ Path buildHook = absPath(getEnv("NIX_BUILD_HOOK"));
+
+ /* Create a pipe to get the output of the child. */
+ fromHook.create();
+
+ /* Create the communication pipes. */
+ toHook.create();
+
+ /* Create a pipe to get the output of the builder. */
+ builderOut.create();
+
+ /* Fork the hook. */
+ pid = maybeVfork();
+ switch (pid) {
+
+ case -1:
+ throw SysError("unable to fork");
+
+ case 0:
+ try { /* child */
+
+ commonChildInit(fromHook);
+
+ if (chdir("/") == -1) throw SysError("changing into `/");
+
+ /* Dup the communication pipes. */
+ if (dup2(toHook.readSide, STDIN_FILENO) == -1)
+ throw SysError("dupping to-hook read side");
+
+ /* Use fd 4 for the builder's stdout/stderr. */
+ if (dup2(builderOut.writeSide, 4) == -1)
+ throw SysError("dupping builder's stdout/stderr");
+
+ execl(buildHook.c_str(), buildHook.c_str(), settings.thisSystem.c_str(),
+ (format("%1%") % settings.maxSilentTime).str().c_str(),
+ (format("%1%") % settings.printBuildTrace).str().c_str(),
+ (format("%1%") % settings.buildTimeout).str().c_str(),
+ NULL);
+
+ throw SysError(format("executing `%1%'") % buildHook);
+
+ } catch (std::exception & e) {
+ writeToStderr("build hook error: " + string(e.what()) + "\n");
+ }
+ _exit(1);
+ }
+
+ /* parent */
+ pid.setSeparatePG(true);
+ pid.setKillSignal(SIGTERM);
+ fromHook.writeSide.close();
+ toHook.readSide.close();
+}
+
+
+HookInstance::~HookInstance()
+{
+ try {
+ pid.kill();
+ } catch (...) {
+ ignoreException();
+ }
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+typedef map<string, string> HashRewrites;
+
+
+string rewriteHashes(string s, const HashRewrites & rewrites)
+{
+ foreach (HashRewrites::const_iterator, i, rewrites) {
+ assert(i->first.size() == i->second.size());
+ size_t j = 0;
+ while ((j = s.find(i->first, j)) != string::npos) {
+ debug(format("rewriting @ %1%") % j);
+ s.replace(j, i->second.size(), i->second);
+ }
+ }
+ return s;
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+typedef enum {rpAccept, rpDecline, rpPostpone} HookReply;
+
+class SubstitutionGoal;
+
+class DerivationGoal : public Goal
+{
+private:
+ /* The path of the derivation. */
+ Path drvPath;
+
+ /* The specific outputs that we need to build. Empty means all of
+ them. */
+ StringSet wantedOutputs;
+
+ /* Whether additional wanted outputs have been added. */
+ bool needRestart;
+
+ /* Whether to retry substituting the outputs after building the
+ inputs. */
+ bool retrySubstitution;
+
+ /* The derivation stored at drvPath. */
+ Derivation drv;
+
+ /* The remainder is state held during the build. */
+
+ /* Locks on the output paths. */
+ PathLocks outputLocks;
+
+ /* All input paths (that is, the union of FS closures of the
+ immediate input paths). */
+ PathSet inputPaths;
+
+ /* Referenceable paths (i.e., input and output paths). */
+ PathSet allPaths;
+
+ /* Outputs that are already valid. If we're repairing, these are
+ the outputs that are valid *and* not corrupt. */
+ PathSet validPaths;
+
+ /* Outputs that are corrupt or not valid. */
+ PathSet missingPaths;
+
+ /* User selected for running the builder. */
+ UserLock buildUser;
+
+ /* The process ID of the builder. */
+ Pid pid;
+
+ /* The temporary directory. */
+ Path tmpDir;
+
+ /* File descriptor for the log file. */
+ FILE * fLogFile;
+ BZFILE * bzLogFile;
+ AutoCloseFD fdLogFile;
+
+ /* Number of bytes received from the builder's stdout/stderr. */
+ unsigned long logSize;
+
+ /* Pipe for the builder's standard output/error. */
+ Pipe builderOut;
+
+ /* The build hook. */
+ std::shared_ptr<HookInstance> hook;
+
+ /* Whether we're currently doing a chroot build. */
+ bool useChroot;
+
+ Path chrootRootDir;
+
+ /* RAII object to delete the chroot directory. */
+ std::shared_ptr<AutoDelete> autoDelChroot;
+
+ /* All inputs that are regular files. */
+ PathSet regularInputPaths;
+
+ /* Whether this is a fixed-output derivation. */
+ bool fixedOutput;
+
+ typedef void (DerivationGoal::*GoalState)();
+ GoalState state;
+
+ /* Stuff we need to pass to initChild(). */
+ typedef map<Path, Path> DirsInChroot; // maps target path to source path
+ DirsInChroot dirsInChroot;
+ typedef map<string, string> Environment;
+ Environment env;
+
+ /* Hash rewriting. */
+ HashRewrites rewritesToTmp, rewritesFromTmp;
+ typedef map<Path, Path> RedirectedOutputs;
+ RedirectedOutputs redirectedOutputs;
+
+ BuildMode buildMode;
+
+ /* If we're repairing without a chroot, there may be outputs that
+ are valid but corrupt. So we redirect these outputs to
+ temporary paths. */
+ PathSet redirectedBadOutputs;
+
+ /* Set of inodes seen during calls to canonicalisePathMetaData()
+ for this build's outputs. This needs to be shared between
+ outputs to allow hard links between outputs. */
+ InodesSeen inodesSeen;
+
+ /* Magic exit code denoting that setting up the child environment
+ failed. (It's possible that the child actually returns the
+ exit code, but ah well.) */
+ const static int childSetupFailed = 189;
+
+public:
+ DerivationGoal(const Path & drvPath, const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode = bmNormal);
+ ~DerivationGoal();
+
+ void cancel(bool timeout);
+
+ void work();
+
+ Path getDrvPath()
+ {
+ return drvPath;
+ }
+
+ /* Add wanted outputs to an already existing derivation goal. */
+ void addWantedOutputs(const StringSet & outputs);
+
+private:
+ /* The states. */
+ void init();
+ void haveDerivation();
+ void outputsSubstituted();
+ void closureRepaired();
+ void inputsRealised();
+ void tryToBuild();
+ void buildDone();
+
+ /* Is the build hook willing to perform the build? */
+ HookReply tryBuildHook();
+
+ /* Start building a derivation. */
+ void startBuilder();
+
+ /* Initialise the builder's process. */
+ void initChild();
+
+ friend int childEntry(void *);
+
+ /* Check that the derivation outputs all exist and register them
+ as valid. */
+ void registerOutputs();
+
+ /* Open a log file and a pipe to it. */
+ Path openLogFile();
+
+ /* Close the log file. */
+ void closeLogFile();
+
+ /* Delete the temporary directory, if we have one. */
+ void deleteTmpDir(bool force);
+
+ /* Callback used by the worker to write to the log. */
+ void handleChildOutput(int fd, const string & data);
+ void handleEOF(int fd);
+
+ /* Return the set of (in)valid paths. */
+ PathSet checkPathValidity(bool returnValid, bool checkHash);
+
+ /* Abort the goal if `path' failed to build. */
+ bool pathFailed(const Path & path);
+
+ /* Forcibly kill the child process, if any. */
+ void killChild();
+
+ Path addHashRewrite(const Path & path);
+
+ void repairClosure();
+};
+
+
+DerivationGoal::DerivationGoal(const Path & drvPath, const StringSet & wantedOutputs, Worker & worker, BuildMode buildMode)
+ : Goal(worker)
+ , wantedOutputs(wantedOutputs)
+ , needRestart(false)
+ , retrySubstitution(false)
+ , fLogFile(0)
+ , bzLogFile(0)
+ , useChroot(false)
+ , buildMode(buildMode)
+{
+ this->drvPath = drvPath;
+ state = &DerivationGoal::init;
+ name = (format("building of `%1%'") % drvPath).str();
+ trace("created");
+}
+
+
+DerivationGoal::~DerivationGoal()
+{
+ /* Careful: we should never ever throw an exception from a
+ destructor. */
+ try {
+ killChild();
+ deleteTmpDir(false);
+ closeLogFile();
+ } catch (...) {
+ ignoreException();
+ }
+}
+
+
+void DerivationGoal::killChild()
+{
+ if (pid != -1) {
+ worker.childTerminated(pid);
+
+ if (buildUser.enabled()) {
+ /* If we're using a build user, then there is a tricky
+ race condition: if we kill the build user before the
+ child has done its setuid() to the build user uid, then
+ it won't be killed, and we'll potentially lock up in
+ pid.wait(). So also send a conventional kill to the
+ child. */
+ ::kill(-pid, SIGKILL); /* ignore the result */
+ buildUser.kill();
+ pid.wait(true);
+ } else
+ pid.kill();
+
+ assert(pid == -1);
+ }
+
+ hook.reset();
+}
+
+
+void DerivationGoal::cancel(bool timeout)
+{
+ if (settings.printBuildTrace && timeout)
+ printMsg(lvlError, format("@ build-failed %1% - timeout") % drvPath);
+ killChild();
+ amDone(ecFailed);
+}
+
+
+void DerivationGoal::work()
+{
+ (this->*state)();
+}
+
+
+void DerivationGoal::addWantedOutputs(const StringSet & outputs)
+{
+ /* If we already want all outputs, there is nothing to do. */
+ if (wantedOutputs.empty()) return;
+
+ if (outputs.empty()) {
+ wantedOutputs.clear();
+ needRestart = true;
+ } else
+ foreach (StringSet::const_iterator, i, outputs)
+ if (wantedOutputs.find(*i) == wantedOutputs.end()) {
+ wantedOutputs.insert(*i);
+ needRestart = true;
+ }
+}
+
+
+void DerivationGoal::init()
+{
+ trace("init");
+
+ if (settings.readOnlyMode)
+ throw Error(format("cannot build derivation `%1%' - no write access to the Nix store") % drvPath);
+
+ /* The first thing to do is to make sure that the derivation
+ exists. If it doesn't, it may be created through a
+ substitute. */
+ addWaitee(worker.makeSubstitutionGoal(drvPath));
+
+ state = &DerivationGoal::haveDerivation;
+}
+
+
+void DerivationGoal::haveDerivation()
+{
+ trace("loading derivation");
+
+ if (nrFailed != 0) {
+ printMsg(lvlError, format("cannot build missing derivation `%1%'") % drvPath);
+ amDone(ecFailed);
+ return;
+ }
+
+ /* `drvPath' should already be a root, but let's be on the safe
+ side: if the user forgot to make it a root, we wouldn't want
+ things being garbage collected while we're busy. */
+ worker.store.addTempRoot(drvPath);
+
+ assert(worker.store.isValidPath(drvPath));
+
+ /* Get the derivation. */
+ drv = derivationFromPath(worker.store, drvPath);
+
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ worker.store.addTempRoot(i->second.path);
+
+ /* Check what outputs paths are not already valid. */
+ PathSet invalidOutputs = checkPathValidity(false, buildMode == bmRepair);
+
+ /* If they are all valid, then we're done. */
+ if (invalidOutputs.size() == 0 && buildMode == bmNormal) {
+ amDone(ecSuccess);
+ return;
+ }
+
+ /* Check whether any output previously failed to build. If so,
+ don't bother. */
+ foreach (PathSet::iterator, i, invalidOutputs)
+ if (pathFailed(*i)) return;
+
+ /* We are first going to try to create the invalid output paths
+ through substitutes. If that doesn't work, we'll build
+ them. */
+ if (settings.useSubstitutes && !willBuildLocally(drv))
+ foreach (PathSet::iterator, i, invalidOutputs)
+ addWaitee(worker.makeSubstitutionGoal(*i, buildMode == bmRepair));
+
+ if (waitees.empty()) /* to prevent hang (no wake-up event) */
+ outputsSubstituted();
+ else
+ state = &DerivationGoal::outputsSubstituted;
+}
+
+
+void DerivationGoal::outputsSubstituted()
+{
+ trace("all outputs substituted (maybe)");
+
+ if (nrFailed > 0 && nrFailed > nrNoSubstituters + nrIncompleteClosure && !settings.tryFallback)
+ throw Error(format("some substitutes for the outputs of derivation `%1%' failed (usually happens due to networking issues); try `--fallback' to build derivation from source ") % drvPath);
+
+ /* If the substitutes form an incomplete closure, then we should
+ build the dependencies of this derivation, but after that, we
+ can still use the substitutes for this derivation itself. */
+ if (nrIncompleteClosure > 0 && !retrySubstitution) retrySubstitution = true;
+
+ nrFailed = nrNoSubstituters = nrIncompleteClosure = 0;
+
+ if (needRestart) {
+ needRestart = false;
+ haveDerivation();
+ return;
+ }
+
+ unsigned int nrInvalid = checkPathValidity(false, buildMode == bmRepair).size();
+ if (buildMode == bmNormal && nrInvalid == 0) {
+ amDone(ecSuccess);
+ return;
+ }
+ if (buildMode == bmRepair && nrInvalid == 0) {
+ repairClosure();
+ return;
+ }
+ if (buildMode == bmCheck && nrInvalid > 0)
+ throw Error(format("some outputs of `%1%' are not valid, so checking is not possible") % drvPath);
+
+ /* Otherwise, at least one of the output paths could not be
+ produced using a substitute. So we have to build instead. */
+
+ /* Make sure checkPathValidity() from now on checks all
+ outputs. */
+ wantedOutputs = PathSet();
+
+ /* The inputs must be built before we can build this goal. */
+ foreach (DerivationInputs::iterator, i, drv.inputDrvs)
+ addWaitee(worker.makeDerivationGoal(i->first, i->second, buildMode == bmRepair ? bmRepair : bmNormal));
+
+ foreach (PathSet::iterator, i, drv.inputSrcs)
+ addWaitee(worker.makeSubstitutionGoal(*i));
+
+ if (waitees.empty()) /* to prevent hang (no wake-up event) */
+ inputsRealised();
+ else
+ state = &DerivationGoal::inputsRealised;
+}
+
+
+void DerivationGoal::repairClosure()
+{
+ /* If we're repairing, we now know that our own outputs are valid.
+ Now check whether the other paths in the outputs closure are
+ good. If not, then start derivation goals for the derivations
+ that produced those outputs. */
+
+ /* Get the output closure. */
+ PathSet outputClosure;
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ computeFSClosure(worker.store, i->second.path, outputClosure);
+
+ /* Filter out our own outputs (which we have already checked). */
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ outputClosure.erase(i->second.path);
+
+ /* Get all dependencies of this derivation so that we know which
+ derivation is responsible for which path in the output
+ closure. */
+ PathSet inputClosure;
+ computeFSClosure(worker.store, drvPath, inputClosure);
+ std::map<Path, Path> outputsToDrv;
+ foreach (PathSet::iterator, i, inputClosure)
+ if (isDerivation(*i)) {
+ Derivation drv = derivationFromPath(worker.store, *i);
+ foreach (DerivationOutputs::iterator, j, drv.outputs)
+ outputsToDrv[j->second.path] = *i;
+ }
+
+ /* Check each path (slow!). */
+ PathSet broken;
+ foreach (PathSet::iterator, i, outputClosure) {
+ if (worker.store.pathContentsGood(*i)) continue;
+ printMsg(lvlError, format("found corrupted or missing path `%1%' in the output closure of `%2%'") % *i % drvPath);
+ Path drvPath2 = outputsToDrv[*i];
+ if (drvPath2 == "")
+ addWaitee(worker.makeSubstitutionGoal(*i, true));
+ else
+ addWaitee(worker.makeDerivationGoal(drvPath2, PathSet(), bmRepair));
+ }
+
+ if (waitees.empty()) {
+ amDone(ecSuccess);
+ return;
+ }
+
+ state = &DerivationGoal::closureRepaired;
+}
+
+
+void DerivationGoal::closureRepaired()
+{
+ trace("closure repaired");
+ if (nrFailed > 0)
+ throw Error(format("some paths in the output closure of derivation `%1%' could not be repaired") % drvPath);
+ amDone(ecSuccess);
+}
+
+
+void DerivationGoal::inputsRealised()
+{
+ trace("all inputs realised");
+
+ if (nrFailed != 0) {
+ printMsg(lvlError,
+ format("cannot build derivation `%1%': %2% dependencies couldn't be built")
+ % drvPath % nrFailed);
+ amDone(ecFailed);
+ return;
+ }
+
+ if (retrySubstitution) {
+ haveDerivation();
+ return;
+ }
+
+ /* Gather information necessary for computing the closure and/or
+ running the build hook. */
+
+ /* The outputs are referenceable paths. */
+ foreach (DerivationOutputs::iterator, i, drv.outputs) {
+ debug(format("building path `%1%'") % i->second.path);
+ allPaths.insert(i->second.path);
+ }
+
+ /* Determine the full set of input paths. */
+
+ /* First, the input derivations. */
+ foreach (DerivationInputs::iterator, i, drv.inputDrvs) {
+ /* Add the relevant output closures of the input derivation
+ `*i' as input paths. Only add the closures of output paths
+ that are specified as inputs. */
+ assert(worker.store.isValidPath(i->first));
+ Derivation inDrv = derivationFromPath(worker.store, i->first);
+ foreach (StringSet::iterator, j, i->second)
+ if (inDrv.outputs.find(*j) != inDrv.outputs.end())
+ computeFSClosure(worker.store, inDrv.outputs[*j].path, inputPaths);
+ else
+ throw Error(
+ format("derivation `%1%' requires non-existent output `%2%' from input derivation `%3%'")
+ % drvPath % *j % i->first);
+ }
+
+ /* Second, the input sources. */
+ foreach (PathSet::iterator, i, drv.inputSrcs)
+ computeFSClosure(worker.store, *i, inputPaths);
+
+ debug(format("added input paths %1%") % showPaths(inputPaths));
+
+ allPaths.insert(inputPaths.begin(), inputPaths.end());
+
+ /* Is this a fixed-output derivation? */
+ fixedOutput = true;
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ if (i->second.hash == "") fixedOutput = false;
+
+ /* Okay, try to build. Note that here we don't wait for a build
+ slot to become available, since we don't need one if there is a
+ build hook. */
+ state = &DerivationGoal::tryToBuild;
+ worker.wakeUp(shared_from_this());
+}
+
+
+PathSet outputPaths(const DerivationOutputs & outputs)
+{
+ PathSet paths;
+ foreach (DerivationOutputs::const_iterator, i, outputs)
+ paths.insert(i->second.path);
+ return paths;
+}
+
+
+static string get(const StringPairs & map, const string & key)
+{
+ StringPairs::const_iterator i = map.find(key);
+ return i == map.end() ? (string) "" : i->second;
+}
+
+
+static bool canBuildLocally(const string & platform)
+{
+ return platform == settings.thisSystem
+#ifdef CAN_DO_LINUX32_BUILDS
+ || (platform == "i686-linux" && settings.thisSystem == "x86_64-linux")
+#endif
+ ;
+}
+
+
+bool willBuildLocally(const Derivation & drv)
+{
+ return get(drv.env, "preferLocalBuild") == "1" && canBuildLocally(drv.platform);
+}
+
+
+void DerivationGoal::tryToBuild()
+{
+ trace("trying to build");
+
+ /* Check for the possibility that some other goal in this process
+ has locked the output since we checked in haveDerivation().
+ (It can't happen between here and the lockPaths() call below
+ because we're not allowing multi-threading.) If so, put this
+ goal to sleep until another goal finishes, then try again. */
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ if (pathIsLockedByMe(i->second.path)) {
+ debug(format("putting derivation `%1%' to sleep because `%2%' is locked by another goal")
+ % drvPath % i->second.path);
+ worker.waitForAnyGoal(shared_from_this());
+ return;
+ }
+
+ /* Obtain locks on all output paths. The locks are automatically
+ released when we exit this function or Nix crashes. If we
+ can't acquire the lock, then continue; hopefully some other
+ goal can start a build, and if not, the main loop will sleep a
+ few seconds and then retry this goal. */
+ if (!outputLocks.lockPaths(outputPaths(drv.outputs), "", false)) {
+ worker.waitForAWhile(shared_from_this());
+ return;
+ }
+
+ /* Now check again whether the outputs are valid. This is because
+ another process may have started building in parallel. After
+ it has finished and released the locks, we can (and should)
+ reuse its results. (Strictly speaking the first check can be
+ omitted, but that would be less efficient.) Note that since we
+ now hold the locks on the output paths, no other process can
+ build this derivation, so no further checks are necessary. */
+ validPaths = checkPathValidity(true, buildMode == bmRepair);
+ assert(buildMode != bmCheck || validPaths.size() == drv.outputs.size());
+ if (buildMode != bmCheck && validPaths.size() == drv.outputs.size()) {
+ debug(format("skipping build of derivation `%1%', someone beat us to it") % drvPath);
+ outputLocks.setDeletion(true);
+ amDone(ecSuccess);
+ return;
+ }
+
+ missingPaths = outputPaths(drv.outputs);
+ if (buildMode != bmCheck)
+ foreach (PathSet::iterator, i, validPaths) missingPaths.erase(*i);
+
+ /* If any of the outputs already exist but are not valid, delete
+ them. */
+ foreach (DerivationOutputs::iterator, i, drv.outputs) {
+ Path path = i->second.path;
+ if (worker.store.isValidPath(path)) continue;
+ if (!pathExists(path)) continue;
+ debug(format("removing invalid path `%1%'") % path);
+ deletePath(path);
+ }
+
+ /* Check again whether any output previously failed to build,
+ because some other process may have tried and failed before we
+ acquired the lock. */
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ if (pathFailed(i->second.path)) return;
+
+ /* Don't do a remote build if the derivation has the attribute
+ `preferLocalBuild' set. Also, check and repair modes are only
+ supported for local builds. */
+ bool buildLocally = buildMode != bmNormal || willBuildLocally(drv);
+
+ /* Is the build hook willing to accept this job? */
+ if (!buildLocally) {
+ switch (tryBuildHook()) {
+ case rpAccept:
+ /* Yes, it has started doing so. Wait until we get
+ EOF from the hook. */
+ state = &DerivationGoal::buildDone;
+ return;
+ case rpPostpone:
+ /* Not now; wait until at least one child finishes or
+ the wake-up timeout expires. */
+ worker.waitForAWhile(shared_from_this());
+ outputLocks.unlock();
+ return;
+ case rpDecline:
+ /* We should do it ourselves. */
+ break;
+ }
+ }
+
+ /* Make sure that we are allowed to start a build. If this
+ derivation prefers to be done locally, do it even if
+ maxBuildJobs is 0. */
+ unsigned int curBuilds = worker.getNrLocalBuilds();
+ if (curBuilds >= settings.maxBuildJobs && !(buildLocally && curBuilds == 0)) {
+ worker.waitForBuildSlot(shared_from_this());
+ outputLocks.unlock();
+ return;
+ }
+
+ try {
+
+ /* Okay, we have to build. */
+ startBuilder();
+
+ } catch (BuildError & e) {
+ printMsg(lvlError, e.msg());
+ outputLocks.unlock();
+ buildUser.release();
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ build-failed %1% - %2% %3%")
+ % drvPath % 0 % e.msg());
+ worker.permanentFailure = true;
+ amDone(ecFailed);
+ return;
+ }
+
+ /* This state will be reached when we get EOF on the child's
+ log pipe. */
+ state = &DerivationGoal::buildDone;
+}
+
+
+void replaceValidPath(const Path & storePath, const Path tmpPath)
+{
+ /* We can't atomically replace storePath (the original) with
+ tmpPath (the replacement), so we have to move it out of the
+ way first. We'd better not be interrupted here, because if
+ we're repairing (say) Glibc, we end up with a broken system. */
+ Path oldPath = (format("%1%.old-%2%-%3%") % storePath % getpid() % rand()).str();
+ if (pathExists(storePath))
+ rename(storePath.c_str(), oldPath.c_str());
+ if (rename(tmpPath.c_str(), storePath.c_str()) == -1)
+ throw SysError(format("moving `%1%' to `%2%'") % tmpPath % storePath);
+ if (pathExists(oldPath))
+ deletePath(oldPath);
+}
+
+
+void DerivationGoal::buildDone()
+{
+ trace("build done");
+
+ /* Since we got an EOF on the logger pipe, the builder is presumed
+ to have terminated. In fact, the builder could also have
+ simply have closed its end of the pipe --- just don't do that
+ :-) */
+ int status;
+ pid_t savedPid;
+ if (hook) {
+ savedPid = hook->pid;
+ status = hook->pid.wait(true);
+ } else {
+ /* !!! this could block! security problem! solution: kill the
+ child */
+ savedPid = pid;
+ status = pid.wait(true);
+ }
+
+ debug(format("builder process for `%1%' finished") % drvPath);
+
+ /* So the child is gone now. */
+ worker.childTerminated(savedPid);
+
+ /* Close the read side of the logger pipe. */
+ if (hook) {
+ hook->builderOut.readSide.close();
+ hook->fromHook.readSide.close();
+ }
+ else builderOut.readSide.close();
+
+ /* Close the log file. */
+ closeLogFile();
+
+ /* When running under a build user, make sure that all processes
+ running under that uid are gone. This is to prevent a
+ malicious user from leaving behind a process that keeps files
+ open and modifies them after they have been chown'ed to
+ root. */
+ if (buildUser.enabled()) buildUser.kill();
+
+ bool diskFull = false;
+
+ try {
+
+ /* Check the exit status. */
+ if (!statusOk(status)) {
+
+ /* Heuristically check whether the build failure may have
+ been caused by a disk full condition. We have no way
+ of knowing whether the build actually got an ENOSPC.
+ So instead, check if the disk is (nearly) full now. If
+ so, we don't mark this build as a permanent failure. */
+#if HAVE_STATVFS
+ unsigned long long required = 8ULL * 1024 * 1024; // FIXME: make configurable
+ struct statvfs st;
+ if (statvfs(settings.nixStore.c_str(), &st) == 0 &&
+ (unsigned long long) st.f_bavail * st.f_bsize < required)
+ diskFull = true;
+ if (statvfs(tmpDir.c_str(), &st) == 0 &&
+ (unsigned long long) st.f_bavail * st.f_bsize < required)
+ diskFull = true;
+#endif
+
+ deleteTmpDir(false);
+
+ /* Move paths out of the chroot for easier debugging of
+ build failures. */
+ if (useChroot && buildMode == bmNormal)
+ foreach (PathSet::iterator, i, missingPaths)
+ if (pathExists(chrootRootDir + *i))
+ rename((chrootRootDir + *i).c_str(), i->c_str());
+
+ if (WIFEXITED(status) && WEXITSTATUS(status) == childSetupFailed)
+ throw Error(format("failed to set up the build environment for `%1%'") % drvPath);
+
+ if (diskFull)
+ printMsg(lvlError, "note: build failure may have been caused by lack of free disk space");
+
+ throw BuildError(format("builder for `%1%' %2%")
+ % drvPath % statusToString(status));
+ }
+
+ /* Compute the FS closure of the outputs and register them as
+ being valid. */
+ registerOutputs();
+
+ if (buildMode == bmCheck) {
+ amDone(ecSuccess);
+ return;
+ }
+
+ /* Delete unused redirected outputs (when doing hash rewriting). */
+ foreach (RedirectedOutputs::iterator, i, redirectedOutputs)
+ if (pathExists(i->second)) deletePath(i->second);
+
+ /* Delete the chroot (if we were using one). */
+ autoDelChroot.reset(); /* this runs the destructor */
+
+ deleteTmpDir(true);
+
+ /* It is now safe to delete the lock files, since all future
+ lockers will see that the output paths are valid; they will
+ not create new lock files with the same names as the old
+ (unlinked) lock files. */
+ outputLocks.setDeletion(true);
+ outputLocks.unlock();
+
+ } catch (BuildError & e) {
+ printMsg(lvlError, e.msg());
+ outputLocks.unlock();
+ buildUser.release();
+
+ /* When using a build hook, the hook will return a remote
+ build failure using exit code 100. Anything else is a hook
+ problem. */
+ bool hookError = hook &&
+ (!WIFEXITED(status) || WEXITSTATUS(status) != 100);
+
+ if (settings.printBuildTrace) {
+ if (hook && hookError)
+ printMsg(lvlError, format("@ hook-failed %1% - %2% %3%")
+ % drvPath % status % e.msg());
+ else
+ printMsg(lvlError, format("@ build-failed %1% - %2% %3%")
+ % drvPath % 1 % e.msg());
+ }
+
+ /* Register the outputs of this build as "failed" so we won't
+ try to build them again (negative caching). However, don't
+ do this for fixed-output derivations, since they're likely
+ to fail for transient reasons (e.g., fetchurl not being
+ able to access the network). Hook errors (like
+ communication problems with the remote machine) shouldn't
+ be cached either. */
+ if (settings.cacheFailure && !hookError && !fixedOutput)
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ worker.store.registerFailedPath(i->second.path);
+
+ worker.permanentFailure = !hookError && !fixedOutput && !diskFull;
+ amDone(ecFailed);
+ return;
+ }
+
+ /* Release the build user, if applicable. */
+ buildUser.release();
+
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ build-succeeded %1% -") % drvPath);
+
+ amDone(ecSuccess);
+}
+
+
+HookReply DerivationGoal::tryBuildHook()
+{
+ if (!settings.useBuildHook || getEnv("NIX_BUILD_HOOK") == "") return rpDecline;
+
+ if (!worker.hook)
+ worker.hook = std::shared_ptr<HookInstance>(new HookInstance);
+
+ /* Tell the hook about system features (beyond the system type)
+ required from the build machine. (The hook could parse the
+ drv file itself, but this is easier.) */
+ Strings features = tokenizeString<Strings>(get(drv.env, "requiredSystemFeatures"));
+ foreach (Strings::iterator, i, features) checkStoreName(*i); /* !!! abuse */
+
+ /* Send the request to the hook. */
+ writeLine(worker.hook->toHook.writeSide, (format("%1% %2% %3% %4%")
+ % (worker.getNrLocalBuilds() < settings.maxBuildJobs ? "1" : "0")
+ % drv.platform % drvPath % concatStringsSep(",", features)).str());
+
+ /* Read the first line of input, which should be a word indicating
+ whether the hook wishes to perform the build. */
+ string reply;
+ while (true) {
+ string s = readLine(worker.hook->fromHook.readSide);
+ if (string(s, 0, 2) == "# ") {
+ reply = string(s, 2);
+ break;
+ }
+ s += "\n";
+ writeToStderr(s);
+ }
+
+ debug(format("hook reply is `%1%'") % reply);
+
+ if (reply == "decline" || reply == "postpone")
+ return reply == "decline" ? rpDecline : rpPostpone;
+ else if (reply != "accept")
+ throw Error(format("bad hook reply `%1%'") % reply);
+
+ printMsg(lvlTalkative, format("using hook to build path(s) %1%") % showPaths(missingPaths));
+
+ hook = worker.hook;
+ worker.hook.reset();
+
+ /* Tell the hook all the inputs that have to be copied to the
+ remote system. This unfortunately has to contain the entire
+ derivation closure to ensure that the validity invariant holds
+ on the remote system. (I.e., it's unfortunate that we have to
+ list it since the remote system *probably* already has it.) */
+ PathSet allInputs;
+ allInputs.insert(inputPaths.begin(), inputPaths.end());
+ computeFSClosure(worker.store, drvPath, allInputs);
+
+ string s;
+ foreach (PathSet::iterator, i, allInputs) { s += *i; s += ' '; }
+ writeLine(hook->toHook.writeSide, s);
+
+ /* Tell the hooks the missing outputs that have to be copied back
+ from the remote system. */
+ s = "";
+ foreach (PathSet::iterator, i, missingPaths) { s += *i; s += ' '; }
+ writeLine(hook->toHook.writeSide, s);
+
+ hook->toHook.writeSide.close();
+
+ /* Create the log file and pipe. */
+ Path logFile = openLogFile();
+
+ set<int> fds;
+ fds.insert(hook->fromHook.readSide);
+ fds.insert(hook->builderOut.readSide);
+ worker.childStarted(shared_from_this(), hook->pid, fds, false, false);
+
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ build-started %1% - %2% %3%")
+ % drvPath % drv.platform % logFile);
+
+ return rpAccept;
+}
+
+
+void chmod_(const Path & path, mode_t mode)
+{
+ if (chmod(path.c_str(), mode) == -1)
+ throw SysError(format("setting permissions on `%1%'") % path);
+}
+
+
+int childEntry(void * arg)
+{
+ ((DerivationGoal *) arg)->initChild();
+ return 1;
+}
+
+
+void DerivationGoal::startBuilder()
+{
+ startNest(nest, lvlInfo, format(
+ buildMode == bmRepair ? "repairing path(s) %1%" :
+ buildMode == bmCheck ? "checking path(s) %1%" :
+ "building path(s) %1%") % showPaths(missingPaths));
+
+ /* Right platform? */
+ if (!canBuildLocally(drv.platform)) {
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ unsupported-platform %1% %2%") % drvPath % drv.platform);
+ throw Error(
+ format("a `%1%' is required to build `%3%', but I am a `%2%'")
+ % drv.platform % settings.thisSystem % drvPath);
+ }
+
+ /* Construct the environment passed to the builder. */
+
+ /* Most shells initialise PATH to some default (/bin:/usr/bin:...) when
+ PATH is not set. We don't want this, so we fill it in with some dummy
+ value. */
+ env["PATH"] = "/path-not-set";
+
+ /* Set HOME to a non-existing path to prevent certain programs from using
+ /etc/passwd (or NIS, or whatever) to locate the home directory (for
+ example, wget looks for ~/.wgetrc). I.e., these tools use /etc/passwd
+ if HOME is not set, but they will just assume that the settings file
+ they are looking for does not exist if HOME is set but points to some
+ non-existing path. */
+ Path homeDir = "/homeless-shelter";
+ env["HOME"] = homeDir;
+
+ /* Tell the builder where the Nix store is. Usually they
+ shouldn't care, but this is useful for purity checking (e.g.,
+ the compiler or linker might only want to accept paths to files
+ in the store or in the build directory). */
+ env["NIX_STORE"] = settings.nixStore;
+
+ /* The maximum number of cores to utilize for parallel building. */
+ env["NIX_BUILD_CORES"] = (format("%d") % settings.buildCores).str();
+
+ /* Add all bindings specified in the derivation. */
+ foreach (StringPairs::iterator, i, drv.env)
+ env[i->first] = i->second;
+
+ /* Create a temporary directory where the build will take
+ place. */
+ tmpDir = createTempDir("", "nix-build-" + storePathToName(drvPath), false, false, 0700);
+
+ /* For convenience, set an environment pointing to the top build
+ directory. */
+ env["NIX_BUILD_TOP"] = tmpDir;
+
+ /* Also set TMPDIR and variants to point to this directory. */
+ env["TMPDIR"] = env["TEMPDIR"] = env["TMP"] = env["TEMP"] = tmpDir;
+
+ /* Explicitly set PWD to prevent problems with chroot builds. In
+ particular, dietlibc cannot figure out the cwd because the
+ inode of the current directory doesn't appear in .. (because
+ getdents returns the inode of the mount point). */
+ env["PWD"] = tmpDir;
+
+ /* Compatibility hack with Nix <= 0.7: if this is a fixed-output
+ derivation, tell the builder, so that for instance `fetchurl'
+ can skip checking the output. On older Nixes, this environment
+ variable won't be set, so `fetchurl' will do the check. */
+ if (fixedOutput) env["NIX_OUTPUT_CHECKED"] = "1";
+
+ /* *Only* if this is a fixed-output derivation, propagate the
+ values of the environment variables specified in the
+ `impureEnvVars' attribute to the builder. This allows for
+ instance environment variables for proxy configuration such as
+ `http_proxy' to be easily passed to downloaders like
+ `fetchurl'. Passing such environment variables from the caller
+ to the builder is generally impure, but the output of
+ fixed-output derivations is by definition pure (since we
+ already know the cryptographic hash of the output). */
+ if (fixedOutput) {
+ Strings varNames = tokenizeString<Strings>(get(drv.env, "impureEnvVars"));
+ foreach (Strings::iterator, i, varNames) env[*i] = getEnv(*i);
+ }
+
+ /* The `exportReferencesGraph' feature allows the references graph
+ to be passed to a builder. This attribute should be a list of
+ pairs [name1 path1 name2 path2 ...]. The references graph of
+ each `pathN' will be stored in a text file `nameN' in the
+ temporary build directory. The text files have the format used
+ by `nix-store --register-validity'. However, the deriver
+ fields are left empty. */
+ string s = get(drv.env, "exportReferencesGraph");
+ Strings ss = tokenizeString<Strings>(s);
+ if (ss.size() % 2 != 0)
+ throw BuildError(format("odd number of tokens in `exportReferencesGraph': `%1%'") % s);
+ for (Strings::iterator i = ss.begin(); i != ss.end(); ) {
+ string fileName = *i++;
+ checkStoreName(fileName); /* !!! abuse of this function */
+
+ /* Check that the store path is valid. */
+ Path storePath = *i++;
+ if (!isInStore(storePath))
+ throw BuildError(format("`exportReferencesGraph' contains a non-store path `%1%'")
+ % storePath);
+ storePath = toStorePath(storePath);
+ if (!worker.store.isValidPath(storePath))
+ throw BuildError(format("`exportReferencesGraph' contains an invalid path `%1%'")
+ % storePath);
+
+ /* If there are derivations in the graph, then include their
+ outputs as well. This is useful if you want to do things
+ like passing all build-time dependencies of some path to a
+ derivation that builds a NixOS DVD image. */
+ PathSet paths, paths2;
+ computeFSClosure(worker.store, storePath, paths);
+ paths2 = paths;
+
+ foreach (PathSet::iterator, j, paths2) {
+ if (isDerivation(*j)) {
+ Derivation drv = derivationFromPath(worker.store, *j);
+ foreach (DerivationOutputs::iterator, k, drv.outputs)
+ computeFSClosure(worker.store, k->second.path, paths);
+ }
+ }
+
+ /* Write closure info to `fileName'. */
+ writeFile(tmpDir + "/" + fileName,
+ worker.store.makeValidityRegistration(paths, false, false));
+ }
+
+
+ /* If `build-users-group' is not empty, then we have to build as
+ one of the members of that group. */
+ if (settings.buildUsersGroup != "") {
+ buildUser.acquire();
+ assert(buildUser.getUID() != 0);
+ assert(buildUser.getGID() != 0);
+
+ /* Make sure that no other processes are executing under this
+ uid. */
+ buildUser.kill();
+
+ /* Change ownership of the temporary build directory. */
+ if (chown(tmpDir.c_str(), buildUser.getUID(), buildUser.getGID()) == -1)
+ throw SysError(format("cannot change ownership of `%1%'") % tmpDir);
+
+ /* Check that the Nix store has the appropriate permissions,
+ i.e., owned by root and mode 1775 (sticky bit on so that
+ the builder can create its output but not mess with the
+ outputs of other processes). */
+ struct stat st;
+ if (stat(settings.nixStore.c_str(), &st) == -1)
+ throw SysError(format("cannot stat `%1%'") % settings.nixStore);
+ if (!(st.st_mode & S_ISVTX) ||
+ ((st.st_mode & S_IRWXG) != S_IRWXG) ||
+ (st.st_gid != buildUser.getGID()))
+ throw Error(format(
+ "builder does not have write permission to `%2%'; "
+ "try `chgrp %1% %2%; chmod 1775 %2%'")
+ % buildUser.getGID() % settings.nixStore);
+ }
+
+
+ /* Are we doing a chroot build? Note that fixed-output
+ derivations are never done in a chroot, mainly so that
+ functions like fetchurl (which needs a proper /etc/resolv.conf)
+ work properly. Purity checking for fixed-output derivations
+ is somewhat pointless anyway. */
+ useChroot = settings.useChroot;
+
+ if (fixedOutput) useChroot = false;
+
+ /* Hack to allow derivations to disable chroot builds. */
+ if (get(drv.env, "__noChroot") == "1") useChroot = false;
+
+ if (useChroot) {
+#if CHROOT_ENABLED
+ /* Create a temporary directory in which we set up the chroot
+ environment using bind-mounts. We put it in the Nix store
+ to ensure that we can create hard-links to non-directory
+ inputs in the fake Nix store in the chroot (see below). */
+ chrootRootDir = drvPath + ".chroot";
+ if (pathExists(chrootRootDir)) deletePath(chrootRootDir);
+
+ /* Clean up the chroot directory automatically. */
+ autoDelChroot = std::shared_ptr<AutoDelete>(new AutoDelete(chrootRootDir));
+
+ printMsg(lvlChatty, format("setting up chroot environment in `%1%'") % chrootRootDir);
+
+ /* Create a writable /tmp in the chroot. Many builders need
+ this. (Of course they should really respect $TMPDIR
+ instead.) */
+ Path chrootTmpDir = chrootRootDir + "/tmp";
+ createDirs(chrootTmpDir);
+ chmod_(chrootTmpDir, 01777);
+
+ /* Create a /etc/passwd with entries for the build user and the
+ nobody account. The latter is kind of a hack to support
+ Samba-in-QEMU. */
+ createDirs(chrootRootDir + "/etc");
+
+ writeFile(chrootRootDir + "/etc/passwd",
+ (format(
+ "nixbld:x:%1%:%2%:Nix build user:/:/noshell\n"
+ "nobody:x:65534:65534:Nobody:/:/noshell\n")
+ % (buildUser.enabled() ? buildUser.getUID() : getuid())
+ % (buildUser.enabled() ? buildUser.getGID() : getgid())).str());
+
+ /* Declare the build user's group so that programs get a consistent
+ view of the system (e.g., "id -gn"). */
+ writeFile(chrootRootDir + "/etc/group",
+ (format("nixbld:!:%1%:\n")
+ % (buildUser.enabled() ? buildUser.getGID() : getgid())).str());
+
+ /* Create /etc/hosts with localhost entry. */
+ writeFile(chrootRootDir + "/etc/hosts", "127.0.0.1 localhost\n");
+
+ /* Bind-mount a user-configurable set of directories from the
+ host file system. */
+ foreach (StringSet::iterator, i, settings.dirsInChroot) {
+ size_t p = i->find('=');
+ if (p == string::npos)
+ dirsInChroot[*i] = *i;
+ else
+ dirsInChroot[string(*i, 0, p)] = string(*i, p + 1);
+ }
+ dirsInChroot[tmpDir] = tmpDir;
+
+ /* Make the closure of the inputs available in the chroot,
+ rather than the whole Nix store. This prevents any access
+ to undeclared dependencies. Directories are bind-mounted,
+ while other inputs are hard-linked (since only directories
+ can be bind-mounted). !!! As an extra security
+ precaution, make the fake Nix store only writable by the
+ build user. */
+ createDirs(chrootRootDir + settings.nixStore);
+ chmod_(chrootRootDir + settings.nixStore, 01777);
+
+ foreach (PathSet::iterator, i, inputPaths) {
+ struct stat st;
+ if (lstat(i->c_str(), &st))
+ throw SysError(format("getting attributes of path `%1%'") % *i);
+ if (S_ISDIR(st.st_mode))
+ dirsInChroot[*i] = *i;
+ else {
+ Path p = chrootRootDir + *i;
+ if (link(i->c_str(), p.c_str()) == -1) {
+ /* Hard-linking fails if we exceed the maximum
+ link count on a file (e.g. 32000 of ext3),
+ which is quite possible after a `nix-store
+ --optimise'. */
+ if (errno != EMLINK)
+ throw SysError(format("linking `%1%' to `%2%'") % p % *i);
+ StringSink sink;
+ dumpPath(*i, sink);
+ StringSource source(sink.s);
+ restorePath(p, source);
+ }
+
+ regularInputPaths.insert(*i);
+ }
+ }
+
+ /* If we're repairing or checking, it's possible that we're
+ rebuilding a path that is in settings.dirsInChroot
+ (typically the dependencies of /bin/sh). Throw them
+ out. */
+ if (buildMode != bmNormal)
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ dirsInChroot.erase(i->second.path);
+
+#else
+ throw Error("chroot builds are not supported on this platform");
+#endif
+ }
+
+ else {
+
+ if (pathExists(homeDir))
+ throw Error(format("directory `%1%' exists; please remove it") % homeDir);
+
+ /* We're not doing a chroot build, but we have some valid
+ output paths. Since we can't just overwrite or delete
+ them, we have to do hash rewriting: i.e. in the
+ environment/arguments passed to the build, we replace the
+ hashes of the valid outputs with unique dummy strings;
+ after the build, we discard the redirected outputs
+ corresponding to the valid outputs, and rewrite the
+ contents of the new outputs to replace the dummy strings
+ with the actual hashes. */
+ if (validPaths.size() > 0)
+ foreach (PathSet::iterator, i, validPaths)
+ addHashRewrite(*i);
+
+ /* If we're repairing, then we don't want to delete the
+ corrupt outputs in advance. So rewrite them as well. */
+ if (buildMode == bmRepair)
+ foreach (PathSet::iterator, i, missingPaths)
+ if (worker.store.isValidPath(*i) && pathExists(*i)) {
+ addHashRewrite(*i);
+ redirectedBadOutputs.insert(*i);
+ }
+ }
+
+
+ /* Run the builder. */
+ printMsg(lvlChatty, format("executing builder `%1%'") % drv.builder);
+
+ /* Create the log file. */
+ Path logFile = openLogFile();
+
+ /* Create a pipe to get the output of the builder. */
+ builderOut.create();
+
+ /* Fork a child to build the package. Note that while we
+ currently use forks to run and wait for the children, it
+ shouldn't be hard to use threads for this on systems where
+ fork() is unavailable or inefficient.
+
+ If we're building in a chroot, then also set up private
+ namespaces for the build:
+
+ - The PID namespace causes the build to start as PID 1.
+ Processes outside of the chroot are not visible to those on
+ the inside, but processes inside the chroot are visible from
+ the outside (though with different PIDs).
+
+ - The private mount namespace ensures that all the bind mounts
+ we do will only show up in this process and its children, and
+ will disappear automatically when we're done.
+
+ - The private network namespace ensures that the builder cannot
+ talk to the outside world (or vice versa). It only has a
+ private loopback interface.
+
+ - The IPC namespace prevents the builder from communicating
+ with outside processes using SysV IPC mechanisms (shared
+ memory, message queues, semaphores). It also ensures that
+ all IPC objects are destroyed when the builder exits.
+
+ - The UTS namespace ensures that builders see a hostname of
+ localhost rather than the actual hostname.
+ */
+#if CHROOT_ENABLED
+ if (useChroot) {
+ char stack[32 * 1024];
+ pid = clone(childEntry, stack + sizeof(stack) - 8,
+ CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWNET | CLONE_NEWIPC | CLONE_NEWUTS | SIGCHLD, this);
+ } else
+#endif
+ {
+ pid = fork();
+ if (pid == 0) initChild();
+ }
+
+ if (pid == -1) throw SysError("unable to fork");
+
+ /* parent */
+ pid.setSeparatePG(true);
+ builderOut.writeSide.close();
+ worker.childStarted(shared_from_this(), pid,
+ singleton<set<int> >(builderOut.readSide), true, true);
+
+ if (settings.printBuildTrace) {
+ printMsg(lvlError, format("@ build-started %1% - %2% %3%")
+ % drvPath % drv.platform % logFile);
+ }
+}
+
+
+void DerivationGoal::initChild()
+{
+ /* Warning: in the child we should absolutely not make any SQLite
+ calls! */
+
+ bool inSetup = true;
+
+ try { /* child */
+
+#if CHROOT_ENABLED
+ if (useChroot) {
+ /* Initialise the loopback interface. */
+ AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP));
+ if (fd == -1) throw SysError("cannot open IP socket");
+
+ struct ifreq ifr;
+ strcpy(ifr.ifr_name, "lo");
+ ifr.ifr_flags = IFF_UP | IFF_LOOPBACK | IFF_RUNNING;
+ if (ioctl(fd, SIOCSIFFLAGS, &ifr) == -1)
+ throw SysError("cannot set loopback interface flags");
+
+ fd.close();
+
+ /* Set the hostname etc. to fixed values. */
+ char hostname[] = "localhost";
+ sethostname(hostname, sizeof(hostname));
+ char domainname[] = "(none)"; // kernel default
+ setdomainname(domainname, sizeof(domainname));
+
+ /* Make all filesystems private. This is necessary
+ because subtrees may have been mounted as "shared"
+ (MS_SHARED). (Systemd does this, for instance.) Even
+ though we have a private mount namespace, mounting
+ filesystems on top of a shared subtree still propagates
+ outside of the namespace. Making a subtree private is
+ local to the namespace, though, so setting MS_PRIVATE
+ does not affect the outside world. */
+ Strings mounts = tokenizeString<Strings>(readFile("/proc/self/mountinfo", true), "\n");
+ foreach (Strings::iterator, i, mounts) {
+ vector<string> fields = tokenizeString<vector<string> >(*i, " ");
+ string fs = decodeOctalEscaped(fields.at(4));
+ if (mount(0, fs.c_str(), 0, MS_PRIVATE, 0) == -1)
+ throw SysError(format("unable to make filesystem `%1%' private") % fs);
+ }
+
+ /* Set up a nearly empty /dev, unless the user asked to
+ bind-mount the host /dev. */
+ if (dirsInChroot.find("/dev") == dirsInChroot.end()) {
+ createDirs(chrootRootDir + "/dev/shm");
+ createDirs(chrootRootDir + "/dev/pts");
+ Strings ss;
+ ss.push_back("/dev/full");
+#ifdef __linux__
+ if (pathExists("/dev/kvm"))
+ ss.push_back("/dev/kvm");
+#endif
+ ss.push_back("/dev/null");
+ ss.push_back("/dev/random");
+ ss.push_back("/dev/tty");
+ ss.push_back("/dev/urandom");
+ ss.push_back("/dev/zero");
+ foreach (Strings::iterator, i, ss) dirsInChroot[*i] = *i;
+ createSymlink("/proc/self/fd", chrootRootDir + "/dev/fd");
+ createSymlink("/proc/self/fd/0", chrootRootDir + "/dev/stdin");
+ createSymlink("/proc/self/fd/1", chrootRootDir + "/dev/stdout");
+ createSymlink("/proc/self/fd/2", chrootRootDir + "/dev/stderr");
+ }
+
+ /* Bind-mount all the directories from the "host"
+ filesystem that we want in the chroot
+ environment. */
+ foreach (DirsInChroot::iterator, i, dirsInChroot) {
+ struct stat st;
+ Path source = i->second;
+ Path target = chrootRootDir + i->first;
+ if (source == "/proc") continue; // backwards compatibility
+ debug(format("bind mounting `%1%' to `%2%'") % source % target);
+ if (stat(source.c_str(), &st) == -1)
+ throw SysError(format("getting attributes of path `%1%'") % source);
+ if (S_ISDIR(st.st_mode))
+ createDirs(target);
+ else {
+ createDirs(dirOf(target));
+ writeFile(target, "");
+ }
+ if (mount(source.c_str(), target.c_str(), "", MS_BIND, 0) == -1)
+ throw SysError(format("bind mount from `%1%' to `%2%' failed") % source % target);
+ }
+
+ /* Bind a new instance of procfs on /proc to reflect our
+ private PID namespace. */
+ createDirs(chrootRootDir + "/proc");
+ if (mount("none", (chrootRootDir + "/proc").c_str(), "proc", 0, 0) == -1)
+ throw SysError("mounting /proc");
+
+ /* Mount a new tmpfs on /dev/shm to ensure that whatever
+ the builder puts in /dev/shm is cleaned up automatically. */
+ if (pathExists("/dev/shm") && mount("none", (chrootRootDir + "/dev/shm").c_str(), "tmpfs", 0, 0) == -1)
+ throw SysError("mounting /dev/shm");
+
+ /* Mount a new devpts on /dev/pts. Note that this
+ requires the kernel to be compiled with
+ CONFIG_DEVPTS_MULTIPLE_INSTANCES=y (which is the case
+ if /dev/ptx/ptmx exists). */
+ if (pathExists("/dev/pts/ptmx") &&
+ !pathExists(chrootRootDir + "/dev/ptmx")
+ && dirsInChroot.find("/dev/pts") == dirsInChroot.end())
+ {
+ if (mount("none", (chrootRootDir + "/dev/pts").c_str(), "devpts", 0, "newinstance,mode=0620") == -1)
+ throw SysError("mounting /dev/pts");
+ createSymlink("/dev/pts/ptmx", chrootRootDir + "/dev/ptmx");
+
+ /* Make sure /dev/pts/ptmx is world-writable. With some
+ Linux versions, it is created with permissions 0. */
+ chmod_(chrootRootDir + "/dev/pts/ptmx", 0666);
+ }
+
+ /* Do the chroot(). Below we do a chdir() to the
+ temporary build directory to make sure the current
+ directory is in the chroot. (Actually the order
+ doesn't matter, since due to the bind mount tmpDir and
+ tmpRootDit/tmpDir are the same directories.) */
+ if (chroot(chrootRootDir.c_str()) == -1)
+ throw SysError(format("cannot change root directory to `%1%'") % chrootRootDir);
+ }
+#endif
+
+ commonChildInit(builderOut);
+
+ if (chdir(tmpDir.c_str()) == -1)
+ throw SysError(format("changing into `%1%'") % tmpDir);
+
+ /* Close all other file descriptors. */
+ closeMostFDs(set<int>());
+
+#ifdef CAN_DO_LINUX32_BUILDS
+ /* Change the personality to 32-bit if we're doing an
+ i686-linux build on an x86_64-linux machine. */
+ struct utsname utsbuf;
+ uname(&utsbuf);
+ if (drv.platform == "i686-linux" &&
+ (settings.thisSystem == "x86_64-linux" ||
+ (!strcmp(utsbuf.sysname, "Linux") && !strcmp(utsbuf.machine, "x86_64")))) {
+ if (personality(0x0008 | 0x8000000 /* == PER_LINUX32_3GB */) == -1)
+ throw SysError("cannot set i686-linux personality");
+ }
+
+ /* Impersonate a Linux 2.6 machine to get some determinism in
+ builds that depend on the kernel version. */
+ if ((drv.platform == "i686-linux" || drv.platform == "x86_64-linux") && settings.impersonateLinux26) {
+ int cur = personality(0xffffffff);
+ if (cur != -1) personality(cur | 0x0020000 /* == UNAME26 */);
+ }
+#endif
+
+ /* Fill in the environment. */
+ Strings envStrs;
+ foreach (Environment::const_iterator, i, env)
+ envStrs.push_back(rewriteHashes(i->first + "=" + i->second, rewritesToTmp));
+ const char * * envArr = strings2CharPtrs(envStrs);
+
+ Path program = drv.builder.c_str();
+ std::vector<const char *> args; /* careful with c_str()! */
+ string user; /* must be here for its c_str()! */
+
+ /* If we are running in `build-users' mode, then switch to the
+ user we allocated above. Make sure that we drop all root
+ privileges. Note that above we have closed all file
+ descriptors except std*, so that's safe. Also note that
+ setuid() when run as root sets the real, effective and
+ saved UIDs. */
+ if (buildUser.enabled()) {
+ printMsg(lvlChatty, format("switching to user `%1%'") % buildUser.getUser());
+
+ if (setgroups(0, 0) == -1)
+ throw SysError("cannot clear the set of supplementary groups");
+
+ if (setgid(buildUser.getGID()) == -1 ||
+ getgid() != buildUser.getGID() ||
+ getegid() != buildUser.getGID())
+ throw SysError("setgid failed");
+
+ if (setuid(buildUser.getUID()) == -1 ||
+ getuid() != buildUser.getUID() ||
+ geteuid() != buildUser.getUID())
+ throw SysError("setuid failed");
+ }
+
+ /* Fill in the arguments. */
+ string builderBasename = baseNameOf(drv.builder);
+ args.push_back(builderBasename.c_str());
+ foreach (Strings::iterator, i, drv.args)
+ args.push_back(rewriteHashes(*i, rewritesToTmp).c_str());
+ args.push_back(0);
+
+ restoreSIGPIPE();
+
+ /* Execute the program. This should not return. */
+ inSetup = false;
+ execve(program.c_str(), (char * *) &args[0], (char * *) envArr);
+
+ throw SysError(format("executing `%1%'") % drv.builder);
+
+ } catch (std::exception & e) {
+ writeToStderr("build error: " + string(e.what()) + "\n");
+ _exit(inSetup ? childSetupFailed : 1);
+ }
+
+ abort(); /* never reached */
+}
+
+
+/* Parse a list of reference specifiers. Each element must either be
+ a store path, or the symbolic name of the output of the derivation
+ (such as `out'). */
+PathSet parseReferenceSpecifiers(const Derivation & drv, string attr)
+{
+ PathSet result;
+ Paths paths = tokenizeString<Paths>(attr);
+ foreach (Strings::iterator, i, paths) {
+ if (isStorePath(*i))
+ result.insert(*i);
+ else if (drv.outputs.find(*i) != drv.outputs.end())
+ result.insert(drv.outputs.find(*i)->second.path);
+ else throw BuildError(
+ format("derivation contains an illegal reference specifier `%1%'")
+ % *i);
+ }
+ return result;
+}
+
+
+void DerivationGoal::registerOutputs()
+{
+ /* When using a build hook, the build hook can register the output
+ as valid (by doing `nix-store --import'). If so we don't have
+ to do anything here. */
+ if (hook) {
+ bool allValid = true;
+ foreach (DerivationOutputs::iterator, i, drv.outputs)
+ if (!worker.store.isValidPath(i->second.path)) allValid = false;
+ if (allValid) return;
+ }
+
+ ValidPathInfos infos;
+
+ /* Check whether the output paths were created, and grep each
+ output path to determine what other paths it references. Also make all
+ output paths read-only. */
+ foreach (DerivationOutputs::iterator, i, drv.outputs) {
+ Path path = i->second.path;
+ if (missingPaths.find(path) == missingPaths.end()) continue;
+
+ Path actualPath = path;
+ if (useChroot) {
+ actualPath = chrootRootDir + path;
+ if (pathExists(actualPath)) {
+ /* Move output paths from the chroot to the Nix store. */
+ if (buildMode == bmRepair)
+ replaceValidPath(path, actualPath);
+ else
+ if (buildMode != bmCheck && rename(actualPath.c_str(), path.c_str()) == -1)
+ throw SysError(format("moving build output `%1%' from the chroot to the Nix store") % path);
+ }
+ if (buildMode != bmCheck) actualPath = path;
+ } else {
+ Path redirected = redirectedOutputs[path];
+ if (buildMode == bmRepair
+ && redirectedBadOutputs.find(path) != redirectedBadOutputs.end()
+ && pathExists(redirected))
+ replaceValidPath(path, redirected);
+ if (buildMode == bmCheck)
+ actualPath = redirected;
+ }
+
+ struct stat st;
+ if (lstat(actualPath.c_str(), &st) == -1) {
+ if (errno == ENOENT)
+ throw BuildError(
+ format("builder for `%1%' failed to produce output path `%2%'")
+ % drvPath % path);
+ throw SysError(format("getting attributes of path `%1%'") % actualPath);
+ }
+
+#ifndef __CYGWIN__
+ /* Check that the output is not group or world writable, as
+ that means that someone else can have interfered with the
+ build. Also, the output should be owned by the build
+ user. */
+ if ((!S_ISLNK(st.st_mode) && (st.st_mode & (S_IWGRP | S_IWOTH))) ||
+ (buildUser.enabled() && st.st_uid != buildUser.getUID()))
+ throw BuildError(format("suspicious ownership or permission on `%1%'; rejecting this build output") % path);
+#endif
+
+ /* Apply hash rewriting if necessary. */
+ bool rewritten = false;
+ if (!rewritesFromTmp.empty()) {
+ printMsg(lvlError, format("warning: rewriting hashes in `%1%'; cross fingers") % path);
+
+ /* Canonicalise first. This ensures that the path we're
+ rewriting doesn't contain a hard link to /etc/shadow or
+ something like that. */
+ canonicalisePathMetaData(actualPath, buildUser.enabled() ? buildUser.getUID() : -1, inodesSeen);
+
+ /* FIXME: this is in-memory. */
+ StringSink sink;
+ dumpPath(actualPath, sink);
+ deletePath(actualPath);
+ sink.s = rewriteHashes(sink.s, rewritesFromTmp);
+ StringSource source(sink.s);
+ restorePath(actualPath, source);
+
+ rewritten = true;
+ }
+
+ startNest(nest, lvlTalkative,
+ format("scanning for references inside `%1%'") % path);
+
+ /* Check that fixed-output derivations produced the right
+ outputs (i.e., the content hash should match the specified
+ hash). */
+ if (i->second.hash != "") {
+
+ bool recursive; HashType ht; Hash h;
+ i->second.parseHashInfo(recursive, ht, h);
+
+ if (!recursive) {
+ /* The output path should be a regular file without
+ execute permission. */
+ if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0)
+ throw BuildError(
+ format("output path `%1% should be a non-executable regular file") % path);
+ }
+
+ /* Check the hash. */
+ Hash h2 = recursive ? hashPath(ht, actualPath).first : hashFile(ht, actualPath);
+ if (h != h2)
+ throw BuildError(
+ format("output path `%1%' should have %2% hash `%3%', instead has `%4%'")
+ % path % i->second.hashAlgo % printHash16or32(h) % printHash16or32(h2));
+ }
+
+ /* Get rid of all weird permissions. This also checks that
+ all files are owned by the build user, if applicable. */
+ canonicalisePathMetaData(actualPath,
+ buildUser.enabled() && !rewritten ? buildUser.getUID() : -1, inodesSeen);
+
+ /* For this output path, find the references to other paths
+ contained in it. Compute the SHA-256 NAR hash at the same
+ time. The hash is stored in the database so that we can
+ verify later on whether nobody has messed with the store. */
+ HashResult hash;
+ PathSet references = scanForReferences(actualPath, allPaths, hash);
+
+ if (buildMode == bmCheck) {
+ ValidPathInfo info = worker.store.queryPathInfo(path);
+ if (hash.first != info.hash)
+ throw Error(format("derivation `%2%' may not be deterministic: hash mismatch in output `%1%'") % drvPath % path);
+ continue;
+ }
+
+ /* For debugging, print out the referenced and unreferenced
+ paths. */
+ foreach (PathSet::iterator, i, inputPaths) {
+ PathSet::iterator j = references.find(*i);
+ if (j == references.end())
+ debug(format("unreferenced input: `%1%'") % *i);
+ else
+ debug(format("referenced input: `%1%'") % *i);
+ }
+
+ /* If the derivation specifies an `allowedReferences'
+ attribute (containing a list of paths that the output may
+ refer to), check that all references are in that list. !!!
+ allowedReferences should really be per-output. */
+ if (drv.env.find("allowedReferences") != drv.env.end()) {
+ PathSet allowed = parseReferenceSpecifiers(drv, get(drv.env, "allowedReferences"));
+ foreach (PathSet::iterator, i, references)
+ if (allowed.find(*i) == allowed.end())
+ throw BuildError(format("output is not allowed to refer to path `%1%'") % *i);
+ }
+
+ worker.store.optimisePath(path); // FIXME: combine with scanForReferences()
+
+ worker.store.markContentsGood(path);
+
+ ValidPathInfo info;
+ info.path = path;
+ info.hash = hash.first;
+ info.narSize = hash.second;
+ info.references = references;
+ info.deriver = drvPath;
+ infos.push_back(info);
+ }
+
+ if (buildMode == bmCheck) return;
+
+ /* Register each output path as valid, and register the sets of
+ paths referenced by each of them. If there are cycles in the
+ outputs, this will fail. */
+ worker.store.registerValidPaths(infos);
+}
+
+
+string drvsLogDir = "drvs";
+
+
+Path DerivationGoal::openLogFile()
+{
+ logSize = 0;
+
+ if (!settings.keepLog) return "";
+
+ string baseName = baseNameOf(drvPath);
+
+ /* Create a log file. */
+ Path dir = (format("%1%/%2%/%3%/") % settings.nixLogDir % drvsLogDir % string(baseName, 0, 2)).str();
+ createDirs(dir);
+
+ if (settings.compressLog) {
+
+ Path logFileName = (format("%1%/%2%.bz2") % dir % string(baseName, 2)).str();
+ AutoCloseFD fd = open(logFileName.c_str(), O_CREAT | O_WRONLY | O_TRUNC, 0666);
+ if (fd == -1) throw SysError(format("creating log file `%1%'") % logFileName);
+ closeOnExec(fd);
+
+ if (!(fLogFile = fdopen(fd.borrow(), "w")))
+ throw SysError(format("opening file `%1%'") % logFileName);
+
+ int err;
+ if (!(bzLogFile = BZ2_bzWriteOpen(&err, fLogFile, 9, 0, 0)))
+ throw Error(format("cannot open compressed log file `%1%'") % logFileName);
+
+ return logFileName;
+
+ } else {
+ Path logFileName = (format("%1%/%2%") % dir % string(baseName, 2)).str();
+ fdLogFile = open(logFileName.c_str(), O_CREAT | O_WRONLY | O_TRUNC, 0666);
+ if (fdLogFile == -1) throw SysError(format("creating log file `%1%'") % logFileName);
+ closeOnExec(fdLogFile);
+ return logFileName;
+ }
+}
+
+
+void DerivationGoal::closeLogFile()
+{
+ if (bzLogFile) {
+ int err;
+ BZ2_bzWriteClose(&err, bzLogFile, 0, 0, 0);
+ bzLogFile = 0;
+ if (err != BZ_OK) throw Error(format("cannot close compressed log file (BZip2 error = %1%)") % err);
+ }
+
+ if (fLogFile) {
+ fclose(fLogFile);
+ fLogFile = 0;
+ }
+
+ fdLogFile.close();
+}
+
+
+void DerivationGoal::deleteTmpDir(bool force)
+{
+ if (tmpDir != "") {
+ if (settings.keepFailed && !force) {
+ printMsg(lvlError,
+ format("note: keeping build directory `%2%'")
+ % drvPath % tmpDir);
+ chmod(tmpDir.c_str(), 0755);
+ }
+ else
+ deletePath(tmpDir);
+ tmpDir = "";
+ }
+}
+
+
+void DerivationGoal::handleChildOutput(int fd, const string & data)
+{
+ if ((hook && fd == hook->builderOut.readSide) ||
+ (!hook && fd == builderOut.readSide))
+ {
+ logSize += data.size();
+ if (settings.maxLogSize && logSize > settings.maxLogSize) {
+ printMsg(lvlError,
+ format("%1% killed after writing more than %2% bytes of log output")
+ % getName() % settings.maxLogSize);
+ cancel(true); // not really a timeout, but close enough
+ return;
+ }
+ if (verbosity >= settings.buildVerbosity)
+ writeToStderr(data);
+ if (bzLogFile) {
+ int err;
+ BZ2_bzWrite(&err, bzLogFile, (unsigned char *) data.data(), data.size());
+ if (err != BZ_OK) throw Error(format("cannot write to compressed log file (BZip2 error = %1%)") % err);
+ } else if (fdLogFile != -1)
+ writeFull(fdLogFile, (unsigned char *) data.data(), data.size());
+ }
+
+ if (hook && fd == hook->fromHook.readSide)
+ writeToStderr(data);
+}
+
+
+void DerivationGoal::handleEOF(int fd)
+{
+ worker.wakeUp(shared_from_this());
+}
+
+
+PathSet DerivationGoal::checkPathValidity(bool returnValid, bool checkHash)
+{
+ PathSet result;
+ foreach (DerivationOutputs::iterator, i, drv.outputs) {
+ if (!wantOutput(i->first, wantedOutputs)) continue;
+ bool good =
+ worker.store.isValidPath(i->second.path) &&
+ (!checkHash || worker.store.pathContentsGood(i->second.path));
+ if (good == returnValid) result.insert(i->second.path);
+ }
+ return result;
+}
+
+
+bool DerivationGoal::pathFailed(const Path & path)
+{
+ if (!settings.cacheFailure) return false;
+
+ if (!worker.store.hasPathFailed(path)) return false;
+
+ printMsg(lvlError, format("builder for `%1%' failed previously (cached)") % path);
+
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ build-failed %1% - cached") % drvPath);
+
+ worker.permanentFailure = true;
+ amDone(ecFailed);
+
+ return true;
+}
+
+
+Path DerivationGoal::addHashRewrite(const Path & path)
+{
+ string h1 = string(path, settings.nixStore.size() + 1, 32);
+ string h2 = string(printHash32(hashString(htSHA256, "rewrite:" + drvPath + ":" + path)), 0, 32);
+ Path p = settings.nixStore + "/" + h2 + string(path, settings.nixStore.size() + 33);
+ if (pathExists(p)) deletePath(p);
+ assert(path.size() == p.size());
+ rewritesToTmp[h1] = h2;
+ rewritesFromTmp[h2] = h1;
+ redirectedOutputs[path] = p;
+ return p;
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+class SubstitutionGoal : public Goal
+{
+ friend class Worker;
+
+private:
+ /* The store path that should be realised through a substitute. */
+ Path storePath;
+
+ /* The remaining substituters. */
+ Paths subs;
+
+ /* The current substituter. */
+ Path sub;
+
+ /* Whether any substituter can realise this path */
+ bool hasSubstitute;
+
+ /* Path info returned by the substituter's query info operation. */
+ SubstitutablePathInfo info;
+
+ /* Pipe for the substituter's standard output. */
+ Pipe outPipe;
+
+ /* Pipe for the substituter's standard error. */
+ Pipe logPipe;
+
+ /* The process ID of the builder. */
+ Pid pid;
+
+ /* Lock on the store path. */
+ std::shared_ptr<PathLocks> outputLock;
+
+ /* Whether to try to repair a valid path. */
+ bool repair;
+
+ /* Location where we're downloading the substitute. Differs from
+ storePath when doing a repair. */
+ Path destPath;
+
+ typedef void (SubstitutionGoal::*GoalState)();
+ GoalState state;
+
+public:
+ SubstitutionGoal(const Path & storePath, Worker & worker, bool repair = false);
+ ~SubstitutionGoal();
+
+ void cancel(bool timeout);
+
+ void work();
+
+ /* The states. */
+ void init();
+ void tryNext();
+ void gotInfo();
+ void referencesValid();
+ void tryToRun();
+ void finished();
+
+ /* Callback used by the worker to write to the log. */
+ void handleChildOutput(int fd, const string & data);
+ void handleEOF(int fd);
+
+ Path getStorePath() { return storePath; }
+};
+
+
+SubstitutionGoal::SubstitutionGoal(const Path & storePath, Worker & worker, bool repair)
+ : Goal(worker)
+ , hasSubstitute(false)
+ , repair(repair)
+{
+ this->storePath = storePath;
+ state = &SubstitutionGoal::init;
+ name = (format("substitution of `%1%'") % storePath).str();
+ trace("created");
+}
+
+
+SubstitutionGoal::~SubstitutionGoal()
+{
+ if (pid != -1) worker.childTerminated(pid);
+}
+
+
+void SubstitutionGoal::cancel(bool timeout)
+{
+ if (settings.printBuildTrace && timeout)
+ printMsg(lvlError, format("@ substituter-failed %1% timeout") % storePath);
+ if (pid != -1) {
+ pid_t savedPid = pid;
+ pid.kill();
+ worker.childTerminated(savedPid);
+ }
+ amDone(ecFailed);
+}
+
+
+void SubstitutionGoal::work()
+{
+ (this->*state)();
+}
+
+
+void SubstitutionGoal::init()
+{
+ trace("init");
+
+ worker.store.addTempRoot(storePath);
+
+ /* If the path already exists we're done. */
+ if (!repair && worker.store.isValidPath(storePath)) {
+ amDone(ecSuccess);
+ return;
+ }
+
+ if (settings.readOnlyMode)
+ throw Error(format("cannot substitute path `%1%' - no write access to the Nix store") % storePath);
+
+ subs = settings.substituters;
+
+ tryNext();
+}
+
+
+void SubstitutionGoal::tryNext()
+{
+ trace("trying next substituter");
+
+ if (subs.size() == 0) {
+ /* None left. Terminate this goal and let someone else deal
+ with it. */
+ debug(format("path `%1%' is required, but there is no substituter that can build it") % storePath);
+ /* Hack: don't indicate failure if there were no substituters.
+ In that case the calling derivation should just do a
+ build. */
+ amDone(hasSubstitute ? ecFailed : ecNoSubstituters);
+ return;
+ }
+
+ sub = subs.front();
+ subs.pop_front();
+
+ SubstitutablePathInfos infos;
+ PathSet dummy(singleton<PathSet>(storePath));
+ worker.store.querySubstitutablePathInfos(sub, dummy, infos);
+ SubstitutablePathInfos::iterator k = infos.find(storePath);
+ if (k == infos.end()) { tryNext(); return; }
+ info = k->second;
+ hasSubstitute = true;
+
+ /* To maintain the closure invariant, we first have to realise the
+ paths referenced by this one. */
+ foreach (PathSet::iterator, i, info.references)
+ if (*i != storePath) /* ignore self-references */
+ addWaitee(worker.makeSubstitutionGoal(*i));
+
+ if (waitees.empty()) /* to prevent hang (no wake-up event) */
+ referencesValid();
+ else
+ state = &SubstitutionGoal::referencesValid;
+}
+
+
+void SubstitutionGoal::referencesValid()
+{
+ trace("all references realised");
+
+ if (nrFailed > 0) {
+ debug(format("some references of path `%1%' could not be realised") % storePath);
+ amDone(nrNoSubstituters > 0 || nrIncompleteClosure > 0 ? ecIncompleteClosure : ecFailed);
+ return;
+ }
+
+ foreach (PathSet::iterator, i, info.references)
+ if (*i != storePath) /* ignore self-references */
+ assert(worker.store.isValidPath(*i));
+
+ state = &SubstitutionGoal::tryToRun;
+ worker.wakeUp(shared_from_this());
+}
+
+
+void SubstitutionGoal::tryToRun()
+{
+ trace("trying to run");
+
+ /* Make sure that we are allowed to start a build. Note that even
+ is maxBuildJobs == 0 (no local builds allowed), we still allow
+ a substituter to run. This is because substitutions cannot be
+ distributed to another machine via the build hook. */
+ if (worker.getNrLocalBuilds() >= (settings.maxBuildJobs == 0 ? 1 : settings.maxBuildJobs)) {
+ worker.waitForBuildSlot(shared_from_this());
+ return;
+ }
+
+ /* Maybe a derivation goal has already locked this path
+ (exceedingly unlikely, since it should have used a substitute
+ first, but let's be defensive). */
+ outputLock.reset(); // make sure this goal's lock is gone
+ if (pathIsLockedByMe(storePath)) {
+ debug(format("restarting substitution of `%1%' because it's locked by another goal")
+ % storePath);
+ worker.waitForAnyGoal(shared_from_this());
+ return; /* restart in the tryToRun() state when another goal finishes */
+ }
+
+ /* Acquire a lock on the output path. */
+ outputLock = std::shared_ptr<PathLocks>(new PathLocks);
+ if (!outputLock->lockPaths(singleton<PathSet>(storePath), "", false)) {
+ worker.waitForAWhile(shared_from_this());
+ return;
+ }
+
+ /* Check again whether the path is invalid. */
+ if (!repair && worker.store.isValidPath(storePath)) {
+ debug(format("store path `%1%' has become valid") % storePath);
+ outputLock->setDeletion(true);
+ amDone(ecSuccess);
+ return;
+ }
+
+ printMsg(lvlInfo, format("fetching path `%1%'...") % storePath);
+
+ outPipe.create();
+ logPipe.create();
+
+ destPath = repair ? storePath + ".tmp" : storePath;
+
+ /* Remove the (stale) output path if it exists. */
+ if (pathExists(destPath))
+ deletePath(destPath);
+
+ worker.store.setSubstituterEnv();
+
+ /* Fill in the arguments. */
+ Strings args;
+ args.push_back(baseNameOf(sub));
+ args.push_back("--substitute");
+ args.push_back(storePath);
+ args.push_back(destPath);
+ const char * * argArr = strings2CharPtrs(args);
+
+ /* Fork the substitute program. */
+ pid = maybeVfork();
+
+ switch (pid) {
+
+ case -1:
+ throw SysError("unable to fork");
+
+ case 0:
+ try { /* child */
+
+ commonChildInit(logPipe);
+
+ if (dup2(outPipe.writeSide, STDOUT_FILENO) == -1)
+ throw SysError("cannot dup output pipe into stdout");
+
+ execv(sub.c_str(), (char * *) argArr);
+
+ throw SysError(format("executing `%1%'") % sub);
+
+ } catch (std::exception & e) {
+ writeToStderr("substitute error: " + string(e.what()) + "\n");
+ }
+ _exit(1);
+ }
+
+ /* parent */
+ pid.setSeparatePG(true);
+ pid.setKillSignal(SIGTERM);
+ outPipe.writeSide.close();
+ logPipe.writeSide.close();
+ worker.childStarted(shared_from_this(),
+ pid, singleton<set<int> >(logPipe.readSide), true, true);
+
+ state = &SubstitutionGoal::finished;
+
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ substituter-started %1% %2%") % storePath % sub);
+}
+
+
+void SubstitutionGoal::finished()
+{
+ trace("substitute finished");
+
+ /* Since we got an EOF on the logger pipe, the substitute is
+ presumed to have terminated. */
+ pid_t savedPid = pid;
+ int status = pid.wait(true);
+
+ /* So the child is gone now. */
+ worker.childTerminated(savedPid);
+
+ /* Close the read side of the logger pipe. */
+ logPipe.readSide.close();
+
+ /* Get the hash info from stdout. */
+ string dummy = readLine(outPipe.readSide);
+ string expectedHashStr = statusOk(status) ? readLine(outPipe.readSide) : "";
+ outPipe.readSide.close();
+
+ /* Check the exit status and the build result. */
+ HashResult hash;
+ try {
+
+ if (!statusOk(status))
+ throw SubstError(format("fetching path `%1%' %2%")
+ % storePath % statusToString(status));
+
+ if (!pathExists(destPath))
+ throw SubstError(format("substitute did not produce path `%1%'") % destPath);
+
+ hash = hashPath(htSHA256, destPath);
+
+ /* Verify the expected hash we got from the substituer. */
+ if (expectedHashStr != "") {
+ size_t n = expectedHashStr.find(':');
+ if (n == string::npos)
+ throw Error(format("bad hash from substituter: %1%") % expectedHashStr);
+ HashType hashType = parseHashType(string(expectedHashStr, 0, n));
+ if (hashType == htUnknown)
+ throw Error(format("unknown hash algorithm in `%1%'") % expectedHashStr);
+ Hash expectedHash = parseHash16or32(hashType, string(expectedHashStr, n + 1));
+ Hash actualHash = hashType == htSHA256 ? hash.first : hashPath(hashType, destPath).first;
+ if (expectedHash != actualHash)
+ throw SubstError(format("hash mismatch in downloaded path `%1%': expected %2%, got %3%")
+ % storePath % printHash(expectedHash) % printHash(actualHash));
+ }
+
+ } catch (SubstError & e) {
+
+ printMsg(lvlInfo, e.msg());
+
+ if (settings.printBuildTrace) {
+ printMsg(lvlError, format("@ substituter-failed %1% %2% %3%")
+ % storePath % status % e.msg());
+ }
+
+ /* Try the next substitute. */
+ state = &SubstitutionGoal::tryNext;
+ worker.wakeUp(shared_from_this());
+ return;
+ }
+
+ if (repair) replaceValidPath(storePath, destPath);
+
+ canonicalisePathMetaData(storePath, -1);
+
+ worker.store.optimisePath(storePath); // FIXME: combine with hashPath()
+
+ ValidPathInfo info2;
+ info2.path = storePath;
+ info2.hash = hash.first;
+ info2.narSize = hash.second;
+ info2.references = info.references;
+ info2.deriver = info.deriver;
+ worker.store.registerValidPath(info2);
+
+ outputLock->setDeletion(true);
+ outputLock.reset();
+
+ worker.store.markContentsGood(storePath);
+
+ printMsg(lvlChatty,
+ format("substitution of path `%1%' succeeded") % storePath);
+
+ if (settings.printBuildTrace)
+ printMsg(lvlError, format("@ substituter-succeeded %1%") % storePath);
+
+ amDone(ecSuccess);
+}
+
+
+void SubstitutionGoal::handleChildOutput(int fd, const string & data)
+{
+ assert(fd == logPipe.readSide);
+ if (verbosity >= settings.buildVerbosity) writeToStderr(data);
+ /* Don't write substitution output to a log file for now. We
+ probably should, though. */
+}
+
+
+void SubstitutionGoal::handleEOF(int fd)
+{
+ if (fd == logPipe.readSide) worker.wakeUp(shared_from_this());
+}
+
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+static bool working = false;
+
+
+Worker::Worker(LocalStore & store)
+ : store(store)
+{
+ /* Debugging: prevent recursive workers. */
+ if (working) abort();
+ working = true;
+ nrLocalBuilds = 0;
+ lastWokenUp = 0;
+ permanentFailure = false;
+}
+
+
+Worker::~Worker()
+{
+ working = false;
+
+ /* Explicitly get rid of all strong pointers now. After this all
+ goals that refer to this worker should be gone. (Otherwise we
+ are in trouble, since goals may call childTerminated() etc. in
+ their destructors). */
+ topGoals.clear();
+}
+
+
+GoalPtr Worker::makeDerivationGoal(const Path & path, const StringSet & wantedOutputs, BuildMode buildMode)
+{
+ GoalPtr goal = derivationGoals[path].lock();
+ if (!goal) {
+ goal = GoalPtr(new DerivationGoal(path, wantedOutputs, *this, buildMode));
+ derivationGoals[path] = goal;
+ wakeUp(goal);
+ } else
+ (dynamic_cast<DerivationGoal *>(goal.get()))->addWantedOutputs(wantedOutputs);
+ return goal;
+}
+
+
+GoalPtr Worker::makeSubstitutionGoal(const Path & path, bool repair)
+{
+ GoalPtr goal = substitutionGoals[path].lock();
+ if (!goal) {
+ goal = GoalPtr(new SubstitutionGoal(path, *this, repair));
+ substitutionGoals[path] = goal;
+ wakeUp(goal);
+ }
+ return goal;
+}
+
+
+static void removeGoal(GoalPtr goal, WeakGoalMap & goalMap)
+{
+ /* !!! inefficient */
+ for (WeakGoalMap::iterator i = goalMap.begin();
+ i != goalMap.end(); )
+ if (i->second.lock() == goal) {
+ WeakGoalMap::iterator j = i; ++j;
+ goalMap.erase(i);
+ i = j;
+ }
+ else ++i;
+}
+
+
+void Worker::removeGoal(GoalPtr goal)
+{
+ nix::removeGoal(goal, derivationGoals);
+ nix::removeGoal(goal, substitutionGoals);
+ if (topGoals.find(goal) != topGoals.end()) {
+ topGoals.erase(goal);
+ /* If a top-level goal failed, then kill all other goals
+ (unless keepGoing was set). */
+ if (goal->getExitCode() == Goal::ecFailed && !settings.keepGoing)
+ topGoals.clear();
+ }
+
+ /* Wake up goals waiting for any goal to finish. */
+ foreach (WeakGoals::iterator, i, waitingForAnyGoal) {
+ GoalPtr goal = i->lock();
+ if (goal) wakeUp(goal);
+ }
+
+ waitingForAnyGoal.clear();
+}
+
+
+void Worker::wakeUp(GoalPtr goal)
+{
+ goal->trace("woken up");
+ addToWeakGoals(awake, goal);
+}
+
+
+unsigned Worker::getNrLocalBuilds()
+{
+ return nrLocalBuilds;
+}
+
+
+void Worker::childStarted(GoalPtr goal,
+ pid_t pid, const set<int> & fds, bool inBuildSlot,
+ bool respectTimeouts)
+{
+ Child child;
+ child.goal = goal;
+ child.fds = fds;
+ child.timeStarted = child.lastOutput = time(0);
+ child.inBuildSlot = inBuildSlot;
+ child.respectTimeouts = respectTimeouts;
+ children[pid] = child;
+ if (inBuildSlot) nrLocalBuilds++;
+}
+
+
+void Worker::childTerminated(pid_t pid, bool wakeSleepers)
+{
+ assert(pid != -1); /* common mistake */
+
+ Children::iterator i = children.find(pid);
+ assert(i != children.end());
+
+ if (i->second.inBuildSlot) {
+ assert(nrLocalBuilds > 0);
+ nrLocalBuilds--;
+ }
+
+ children.erase(pid);
+
+ if (wakeSleepers) {
+
+ /* Wake up goals waiting for a build slot. */
+ foreach (WeakGoals::iterator, i, wantingToBuild) {
+ GoalPtr goal = i->lock();
+ if (goal) wakeUp(goal);
+ }
+
+ wantingToBuild.clear();
+ }
+}
+
+
+void Worker::waitForBuildSlot(GoalPtr goal)
+{
+ debug("wait for build slot");
+ if (getNrLocalBuilds() < settings.maxBuildJobs)
+ wakeUp(goal); /* we can do it right away */
+ else
+ addToWeakGoals(wantingToBuild, goal);
+}
+
+
+void Worker::waitForAnyGoal(GoalPtr goal)
+{
+ debug("wait for any goal");
+ addToWeakGoals(waitingForAnyGoal, goal);
+}
+
+
+void Worker::waitForAWhile(GoalPtr goal)
+{
+ debug("wait for a while");
+ addToWeakGoals(waitingForAWhile, goal);
+}
+
+
+void Worker::run(const Goals & _topGoals)
+{
+ foreach (Goals::iterator, i, _topGoals) topGoals.insert(*i);
+
+ startNest(nest, lvlDebug, format("entered goal loop"));
+
+ while (1) {
+
+ checkInterrupt();
+
+ /* Call every wake goal. */
+ while (!awake.empty() && !topGoals.empty()) {
+ WeakGoals awake2(awake);
+ awake.clear();
+ foreach (WeakGoals::iterator, i, awake2) {
+ checkInterrupt();
+ GoalPtr goal = i->lock();
+ if (goal) goal->work();
+ if (topGoals.empty()) break;
+ }
+ }
+
+ if (topGoals.empty()) break;
+
+ /* Wait for input. */
+ if (!children.empty() || !waitingForAWhile.empty())
+ waitForInput();
+ else {
+ if (awake.empty() && settings.maxBuildJobs == 0) throw Error(
+ "unable to start any build; either increase `--max-jobs' "
+ "or enable distributed builds");
+ assert(!awake.empty());
+ }
+ }
+
+ /* If --keep-going is not set, it's possible that the main goal
+ exited while some of its subgoals were still active. But if
+ --keep-going *is* set, then they must all be finished now. */
+ assert(!settings.keepGoing || awake.empty());
+ assert(!settings.keepGoing || wantingToBuild.empty());
+ assert(!settings.keepGoing || children.empty());
+}
+
+
+void Worker::waitForInput()
+{
+ printMsg(lvlVomit, "waiting for children");
+
+ /* Process output from the file descriptors attached to the
+ children, namely log output and output path creation commands.
+ We also use this to detect child termination: if we get EOF on
+ the logger pipe of a build, we assume that the builder has
+ terminated. */
+
+ bool useTimeout = false;
+ struct timeval timeout;
+ timeout.tv_usec = 0;
+ time_t before = time(0);
+
+ /* If we're monitoring for silence on stdout/stderr, or if there
+ is a build timeout, then wait for input until the first
+ deadline for any child. */
+ assert(sizeof(time_t) >= sizeof(long));
+ time_t nearest = LONG_MAX; // nearest deadline
+ foreach (Children::iterator, i, children) {
+ if (!i->second.respectTimeouts) continue;
+ if (settings.maxSilentTime != 0)
+ nearest = std::min(nearest, i->second.lastOutput + settings.maxSilentTime);
+ if (settings.buildTimeout != 0)
+ nearest = std::min(nearest, i->second.timeStarted + settings.buildTimeout);
+ }
+ if (nearest != LONG_MAX) {
+ timeout.tv_sec = std::max((time_t) 1, nearest - before);
+ useTimeout = true;
+ printMsg(lvlVomit, format("sleeping %1% seconds") % timeout.tv_sec);
+ }
+
+ /* If we are polling goals that are waiting for a lock, then wake
+ up after a few seconds at most. */
+ if (!waitingForAWhile.empty()) {
+ useTimeout = true;
+ if (lastWokenUp == 0)
+ printMsg(lvlError, "waiting for locks or build slots...");
+ if (lastWokenUp == 0 || lastWokenUp > before) lastWokenUp = before;
+ timeout.tv_sec = std::max((time_t) 1, (time_t) (lastWokenUp + settings.pollInterval - before));
+ } else lastWokenUp = 0;
+
+ using namespace std;
+ /* Use select() to wait for the input side of any logger pipe to
+ become `available'. Note that `available' (i.e., non-blocking)
+ includes EOF. */
+ fd_set fds;
+ FD_ZERO(&fds);
+ int fdMax = 0;
+ foreach (Children::iterator, i, children) {
+ foreach (set<int>::iterator, j, i->second.fds) {
+ FD_SET(*j, &fds);
+ if (*j >= fdMax) fdMax = *j + 1;
+ }
+ }
+
+ if (select(fdMax, &fds, 0, 0, useTimeout ? &timeout : 0) == -1) {
+ if (errno == EINTR) return;
+ throw SysError("waiting for input");
+ }
+
+ time_t after = time(0);
+
+ /* Process all available file descriptors. */
+
+ /* Since goals may be canceled from inside the loop below (causing
+ them go be erased from the `children' map), we have to be
+ careful that we don't keep iterators alive across calls to
+ cancel(). */
+ set<pid_t> pids;
+ foreach (Children::iterator, i, children) pids.insert(i->first);
+
+ foreach (set<pid_t>::iterator, i, pids) {
+ checkInterrupt();
+ Children::iterator j = children.find(*i);
+ if (j == children.end()) continue; // child destroyed
+ GoalPtr goal = j->second.goal.lock();
+ assert(goal);
+
+ set<int> fds2(j->second.fds);
+ foreach (set<int>::iterator, k, fds2) {
+ if (FD_ISSET(*k, &fds)) {
+ unsigned char buffer[4096];
+ ssize_t rd = read(*k, buffer, sizeof(buffer));
+ if (rd == -1) {
+ if (errno != EINTR)
+ throw SysError(format("reading from %1%")
+ % goal->getName());
+ } else if (rd == 0) {
+ debug(format("%1%: got EOF") % goal->getName());
+ goal->handleEOF(*k);
+ j->second.fds.erase(*k);
+ } else {
+ printMsg(lvlVomit, format("%1%: read %2% bytes")
+ % goal->getName() % rd);
+ string data((char *) buffer, rd);
+ j->second.lastOutput = after;
+ goal->handleChildOutput(*k, data);
+ }
+ }
+ }
+
+ if (goal->getExitCode() == Goal::ecBusy &&
+ settings.maxSilentTime != 0 &&
+ j->second.respectTimeouts &&
+ after - j->second.lastOutput >= (time_t) settings.maxSilentTime)
+ {
+ printMsg(lvlError,
+ format("%1% timed out after %2% seconds of silence")
+ % goal->getName() % settings.maxSilentTime);
+ goal->cancel(true);
+ }
+
+ else if (goal->getExitCode() == Goal::ecBusy &&
+ settings.buildTimeout != 0 &&
+ j->second.respectTimeouts &&
+ after - j->second.timeStarted >= (time_t) settings.buildTimeout)
+ {
+ printMsg(lvlError,
+ format("%1% timed out after %2% seconds")
+ % goal->getName() % settings.buildTimeout);
+ goal->cancel(true);
+ }
+ }
+
+ if (!waitingForAWhile.empty() && lastWokenUp + settings.pollInterval <= after) {
+ lastWokenUp = after;
+ foreach (WeakGoals::iterator, i, waitingForAWhile) {
+ GoalPtr goal = i->lock();
+ if (goal) wakeUp(goal);
+ }
+ waitingForAWhile.clear();
+ }
+}
+
+
+unsigned int Worker::exitStatus()
+{
+ return permanentFailure ? 100 : 1;
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+void LocalStore::buildPaths(const PathSet & drvPaths, BuildMode buildMode)
+{
+ startNest(nest, lvlDebug,
+ format("building %1%") % showPaths(drvPaths));
+
+ Worker worker(*this);
+
+ Goals goals;
+ foreach (PathSet::const_iterator, i, drvPaths) {
+ DrvPathWithOutputs i2 = parseDrvPathWithOutputs(*i);
+ if (isDerivation(i2.first))
+ goals.insert(worker.makeDerivationGoal(i2.first, i2.second, buildMode));
+ else
+ goals.insert(worker.makeSubstitutionGoal(*i, buildMode));
+ }
+
+ worker.run(goals);
+
+ PathSet failed;
+ foreach (Goals::iterator, i, goals)
+ if ((*i)->getExitCode() == Goal::ecFailed) {
+ DerivationGoal * i2 = dynamic_cast<DerivationGoal *>(i->get());
+ if (i2) failed.insert(i2->getDrvPath());
+ else failed.insert(dynamic_cast<SubstitutionGoal *>(i->get())->getStorePath());
+ }
+
+ if (!failed.empty())
+ throw Error(format("build of %1% failed") % showPaths(failed), worker.exitStatus());
+}
+
+
+void LocalStore::ensurePath(const Path & path)
+{
+ /* If the path is already valid, we're done. */
+ if (isValidPath(path)) return;
+
+ Worker worker(*this);
+ GoalPtr goal = worker.makeSubstitutionGoal(path);
+ Goals goals = singleton<Goals>(goal);
+
+ worker.run(goals);
+
+ if (goal->getExitCode() != Goal::ecSuccess)
+ throw Error(format("path `%1%' does not exist and cannot be created") % path, worker.exitStatus());
+}
+
+
+void LocalStore::repairPath(const Path & path)
+{
+ Worker worker(*this);
+ GoalPtr goal = worker.makeSubstitutionGoal(path, true);
+ Goals goals = singleton<Goals>(goal);
+
+ worker.run(goals);
+
+ if (goal->getExitCode() != Goal::ecSuccess)
+ throw Error(format("cannot repair path `%1%'") % path, worker.exitStatus());
+}
+
+
+}