lix/src/nix-env/main.cc

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#include "globals.hh"
#include "normalise.hh"
#include "shared.hh"
#include "parser.hh"
#include "eval.hh"
typedef void (* Operation) (EvalState & state,
Strings opFlags, Strings opArgs);
struct DrvInfo
{
string name;
Path drvPath;
Path outPath;
};
typedef map<string, DrvInfo> DrvInfos;
bool parseDerivation(EvalState & state, Expr e, DrvInfo & drv)
{
ATMatcher m;
e = evalExpr(state, e);
if (!(atMatch(m, e) >> "Attrs")) return false;
Expr a = queryAttr(e, "type");
if (!a || evalString(state, a) != "derivation") return false;
a = queryAttr(e, "name");
if (!a) throw badTerm("derivation name missing", e);
drv.name = evalString(state, a);
a = queryAttr(e, "drvPath");
if (!a) throw badTerm("derivation path missing", e);
drv.drvPath = evalPath(state, a);
a = queryAttr(e, "outPath");
if (!a) throw badTerm("output path missing", e);
drv.outPath = evalPath(state, a);
return true;
}
bool parseDerivations(EvalState & state, Expr e, DrvInfos & drvs)
{
e = evalExpr(state, e);
ATermMap drvMap;
queryAllAttrs(e, drvMap);
for (ATermIterator i(drvMap.keys()); i; ++i) {
DrvInfo drv;
debug(format("evaluating attribute `%1%'") % *i);
if (parseDerivation(state, drvMap.get(*i), drv))
drvs[drv.name] = drv;
}
return true;
}
void loadDerivations(EvalState & state, Path nePath, DrvInfos & drvs)
{
Expr e = parseExprFromFile(absPath(nePath));
if (!parseDerivations(state, e, drvs))
throw badTerm("expected set of derivations", e);
}
static Path getLinksDir()
{
return canonPath(nixStateDir + "/links");
}
Path createLink(Path outPath, Path drvPath)
{
Path linksDir = getLinksDir();
unsigned int num = 0;
Strings names = readDirectory(linksDir);
for (Strings::iterator i = names.begin(); i != names.end(); ++i) {
istringstream s(*i);
unsigned int n;
if (s >> n && s.eof() && n > num) num = n + 1;
}
Path linkPath = (format("%1%/%2%") % linksDir % num).str();
if (symlink(outPath.c_str(), linkPath.c_str()) != 0)
throw SysError(format("creating symlink `%1%'") % linkPath);
return linkPath;
}
void installDerivations(EvalState & state,
Path nePath, Strings drvNames)
{
debug(format("installing derivations from `%1%'") % nePath);
/* Fetch all derivations from the input file. */
DrvInfos availDrvs;
loadDerivations(state, nePath, availDrvs);
/* Filter out the ones we're not interested in. */
DrvInfos selectedDrvs;
for (Strings::iterator i = drvNames.begin();
i != drvNames.end(); ++i)
{
DrvInfos::iterator j = availDrvs.find(*i);
if (j == availDrvs.end())
throw Error(format("unknown derivation `%1%'") % *i);
else
selectedDrvs[j->first] = j->second;
}
/* Get the environment builder expression. */
Expr envBuilder = parseExprFromFile("/home/eelco/nix/corepkgs/buildenv"); /* !!! */
/* Construct the whole top level derivation. */
ATermList inputs = ATempty;
for (DrvInfos::iterator i = selectedDrvs.begin();
i != selectedDrvs.end(); ++i)
{
ATerm t = ATmake(
"Attrs(["
"Bind(\"type\", Str(\"derivation\")), "
"Bind(\"name\", Str(<str>)), "
"Bind(\"drvPath\", Path(<str>)), "
"Bind(\"outPath\", Path(<str>))"
"])",
i->second.name.c_str(),
i->second.drvPath.c_str(),
i->second.outPath.c_str());
inputs = ATinsert(inputs, t);
}
ATerm inputs2 = ATmake("List(<term>)", ATreverse(inputs));
/* Also write a copy of the list of inputs to the store; we need
it for future modifications of the environment. */
Path inputsFile = writeTerm(inputs2, "-env-inputs");
Expr topLevel = ATmake(
"Call(<term>, Attrs(["
"Bind(\"system\", Str(<str>)), "
"Bind(\"derivations\", <term>), " // !!! redundant
"Bind(\"manifest\", Path(<str>))"
"]))",
envBuilder, thisSystem.c_str(), inputs2, inputsFile.c_str());
/* Instantiate it. */
debug(format("evaluating builder expression `%1%'") % topLevel);
DrvInfo topLevelDrv;
if (!parseDerivation(state, topLevel, topLevelDrv))
abort();
/* Realise the resulting store expression. */
debug(format("realising user environment"));
Path nfPath = normaliseStoreExpr(topLevelDrv.drvPath);
realiseClosure(nfPath);
/* Switch the current user environment to the output path. */
debug(format("switching to new user environment"));
Path linkPath = createLink(topLevelDrv.outPath, topLevelDrv.drvPath);
// switchLink(current"), link);
}
static void opInstall(EvalState & state,
Strings opFlags, Strings opArgs)
{
if (opArgs.size() < 1) throw UsageError("Nix expression expected");
Path nePath = opArgs.front();
opArgs.pop_front();
installDerivations(state, nePath,
Strings(opArgs.begin(), opArgs.end()));
}
static void opQuery(EvalState & state,
Strings opFlags, Strings opArgs)
{
enum { qName } query = qName;
enum { sInstalled, sAvailable } source = sInstalled;
for (Strings::iterator i = opFlags.begin();
i != opFlags.end(); ++i)
if (*i == "--name") query = qName;
else if (*i == "--installed") source = sInstalled;
else if (*i == "--available" || *i == "-f") source = sAvailable;
else throw UsageError(format("unknown flag `%1%'") % *i);
/* Obtain derivation information from the specified source. */
DrvInfos drvs;
switch (source) {
case sInstalled:
break;
case sAvailable: {
Path nePath = opArgs.front();
opArgs.pop_front();
loadDerivations(state, nePath, drvs);
break;
}
default: abort();
}
/* Perform the specified query on the derivations. */
switch (query) {
case qName: {
if (opArgs.size() != 0) throw UsageError("no arguments expected");
for (DrvInfos::iterator i = drvs.begin(); i != drvs.end(); ++i)
cout << format("%1%\n") % i->second.name;
break;
}
default: abort();
}
}
void run(Strings args)
{
EvalState state;
Strings opFlags, opArgs;
Operation op = 0;
for (Strings::iterator i = args.begin(); i != args.end(); ++i) {
string arg = *i;
Operation oldOp = op;
if (arg == "--install" || arg == "-i")
op = opInstall;
if (arg == "--query" || arg == "-q")
op = opQuery;
else if (arg == "--verbose" || arg == "-v")
verbosity = (Verbosity) ((int) verbosity + 1);
else if (arg[0] == '-')
opFlags.push_back(arg);
else
opArgs.push_back(arg);
if (oldOp && oldOp != op)
throw UsageError("only one operation may be specified");
}
if (!op) throw UsageError("no operation specified");
openDB();
op(state, opFlags, opArgs);
printEvalStats(state);
}
string programId = "nix-env";