nix-super/src/libstore/globals.hh
Shea Levy 4d652875bd Add the pre-build hook.
This hook can be used to set system-specific per-derivation build
settings that don't fit into the derivation model and are too complex or
volatile to be hard-coded into nix. Currently, the pre-build hook can
only add chroot dirs/files through the interface, but it also has full
access to the chroot root.

The specific use case for this is systems where the operating system ABI
is more complex than just the kernel-support system calls. For example,
on OS X there is a set of system-provided frameworks that can reliably
be accessed by any program linked to them, no matter the version the
program is running on. Unfortunately, those frameworks do not
necessarily live in the same locations on each version of OS X, nor do
their dependencies, and thus nix needs to know the specific version of
OS X currently running in order to make those frameworks available. The
pre-build hook is a perfect mechanism for doing just that.
2015-04-18 16:56:02 -04:00

231 lines
6.3 KiB
C++

#pragma once
#include "types.hh"
#include <map>
#include <sys/types.h>
namespace nix {
struct Settings {
typedef std::map<string, string> SettingsMap;
Settings();
void processEnvironment();
void loadConfFile();
void set(const string & name, const string & value);
string get(const string & name, const string & def);
Strings get(const string & name, const Strings & def);
bool get(const string & name, bool def);
int get(const string & name, int def);
void update();
string pack();
void unpack(const string & pack);
SettingsMap getOverrides();
/* The directory where we store sources and derived files. */
Path nixStore;
Path nixDataDir; /* !!! fix */
Path nixPrefix;
/* The directory where we log various operations. */
Path nixLogDir;
/* The directory where state is stored. */
Path nixStateDir;
/* The directory where we keep the SQLite database. */
Path nixDBPath;
/* The directory where configuration files are stored. */
Path nixConfDir;
/* The directory where internal helper programs are stored. */
Path nixLibexecDir;
/* The directory where the main programs are stored. */
Path nixBinDir;
/* File name of the socket the daemon listens to. */
Path nixDaemonSocketFile;
/* Whether to keep temporary directories of failed builds. */
bool keepFailed;
/* Whether to keep building subgoals when a sibling (another
subgoal of the same goal) fails. */
bool keepGoing;
/* Whether, if we cannot realise the known closure corresponding
to a derivation, we should try to normalise the derivation
instead. */
bool tryFallback;
/* Verbosity level for build output. */
Verbosity buildVerbosity;
/* Maximum number of parallel build jobs. 0 means unlimited. */
unsigned int maxBuildJobs;
/* Number of CPU cores to utilize in parallel within a build,
i.e. by passing this number to Make via '-j'. 0 means that the
number of actual CPU cores on the local host ought to be
auto-detected. */
unsigned int buildCores;
/* Read-only mode. Don't copy stuff to the store, don't change
the database. */
bool readOnlyMode;
/* The canonical system name, as returned by config.guess. */
string thisSystem;
/* The maximum time in seconds that a builer can go without
producing any output on stdout/stderr before it is killed. 0
means infinity. */
time_t maxSilentTime;
/* The maximum duration in seconds that a builder can run. 0
means infinity. */
time_t buildTimeout;
/* The substituters. There are programs that can somehow realise
a store path without building, e.g., by downloading it or
copying it from a CD. */
Paths substituters;
/* Whether to use build hooks (for distributed builds). Sometimes
users want to disable this from the command-line. */
bool useBuildHook;
/* Whether buildDerivations() should print out lines on stderr in
a fixed format to allow its progress to be monitored. Each
line starts with a "@". The following are defined:
@ build-started <drvpath> <outpath> <system> <logfile>
@ build-failed <drvpath> <outpath> <exitcode> <error text>
@ build-succeeded <drvpath> <outpath>
@ substituter-started <outpath> <substituter>
@ substituter-failed <outpath> <exitcode> <error text>
@ substituter-succeeded <outpath>
Best combined with --no-build-output, otherwise stderr might
conceivably contain lines in this format printed by the
builders. */
bool printBuildTrace;
/* Amount of reserved space for the garbage collector
(/nix/var/nix/db/reserved). */
off_t reservedSize;
/* Whether SQLite should use fsync. */
bool fsyncMetadata;
/* Whether SQLite should use WAL mode. */
bool useSQLiteWAL;
/* Whether to call sync() before registering a path as valid. */
bool syncBeforeRegistering;
/* Whether to use substitutes. */
bool useSubstitutes;
/* The Unix group that contains the build users. */
string buildUsersGroup;
/* Set of ssh connection strings for the ssh substituter */
Strings sshSubstituterHosts;
/* Whether to use the ssh substituter at all */
bool useSshSubstituter;
/* Whether to impersonate a Linux 2.6 machine on newer kernels. */
bool impersonateLinux26;
/* Whether to store build logs. */
bool keepLog;
/* Whether to compress logs. */
bool compressLog;
/* Maximum number of bytes a builder can write to stdout/stderr
before being killed (0 means no limit). */
unsigned long maxLogSize;
/* Whether to cache build failures. */
bool cacheFailure;
/* How often (in seconds) to poll for locks. */
unsigned int pollInterval;
/* Whether to check if new GC roots can in fact be found by the
garbage collector. */
bool checkRootReachability;
/* Whether the garbage collector should keep outputs of live
derivations. */
bool gcKeepOutputs;
/* Whether the garbage collector should keep derivers of live
paths. */
bool gcKeepDerivations;
/* Whether to automatically replace files with identical contents
with hard links. */
bool autoOptimiseStore;
/* Whether to add derivations as a dependency of user environments
(to prevent them from being GCed). */
bool envKeepDerivations;
/* Whether to lock the Nix client and worker to the same CPU. */
bool lockCPU;
/* Whether to show a stack trace if Nix evaluation fails. */
bool showTrace;
/* A list of URL prefixes that can return Nix build logs. */
Strings logServers;
/* Whether the importNative primop should be enabled */
bool enableImportNative;
/* The hook to run just before a build to set derivation-specific
build settings */
Path preBuildHook;
private:
SettingsMap settings, overrides;
void _get(string & res, const string & name);
void _get(bool & res, const string & name);
void _get(StringSet & res, const string & name);
void _get(Strings & res, const string & name);
template<class N> void _get(N & res, const string & name);
};
// FIXME: don't use a global variable.
extern Settings settings;
extern const string nixVersion;
}