nix build: Use Nix search path

That is, unless --file is specified, the Nix search path is
synthesized into an attribute set. Thus you can say

  $ nix build nixpkgs.hello

assuming $NIX_PATH contains an entry of the form "nixpkgs=...". This
is more verbose than

  $ nix build hello

but is less ambiguous.
This commit is contained in:
Eelco Dolstra 2016-08-23 17:11:19 +02:00
parent 22d6e31fc6
commit d74236d1f2
5 changed files with 57 additions and 13 deletions

View file

@ -379,9 +379,9 @@ void EvalState::addPrimOp(const string & name,
}
void EvalState::getBuiltin(const string & name, Value & v)
Value & EvalState::getBuiltin(const string & name)
{
v = *baseEnv.values[0]->attrs->find(symbols.create(name))->value;
return *baseEnv.values[0]->attrs->find(symbols.create(name))->value;
}
@ -462,7 +462,7 @@ void mkString(Value & v, const char * s)
}
void mkString(Value & v, const string & s, const PathSet & context)
Value & mkString(Value & v, const string & s, const PathSet & context)
{
mkString(v, s.c_str());
if (!context.empty()) {
@ -473,6 +473,7 @@ void mkString(Value & v, const string & s, const PathSet & context)
v.string.context[n++] = dupString(i.c_str());
v.string.context[n] = 0;
}
return v;
}

View file

@ -43,7 +43,7 @@ struct Env
};
void mkString(Value & v, const string & s, const PathSet & context = PathSet());
Value & mkString(Value & v, const string & s, const PathSet & context = PathSet());
void copyContext(const Value & v, PathSet & context);
@ -108,6 +108,8 @@ public:
void addToSearchPath(const string & s);
SearchPath getSearchPath() { return searchPath; }
Path checkSourcePath(const Path & path);
/* Parse a Nix expression from the specified file. */
@ -204,7 +206,7 @@ private:
public:
void getBuiltin(const string & name, Value & v);
Value & getBuiltin(const string & name);
private:

View file

@ -128,9 +128,8 @@ static void getAllExprs(EvalState & state,
}
attrs.insert(attrName);
/* Load the expression on demand. */
Value & vFun(*state.allocValue());
Value & vFun = state.getBuiltin("import");
Value & vArg(*state.allocValue());
state.getBuiltin("import", vFun);
mkString(vArg, path2);
if (v.attrs->size() == v.attrs->capacity())
throw Error(format("too many Nix expressions in directory %1%") % path);

View file

@ -9,6 +9,41 @@
namespace nix {
Value * MixInstallables::buildSourceExpr(EvalState & state)
{
Value * vRoot = state.allocValue();
if (file != "") {
Expr * e = state.parseExprFromFile(resolveExprPath(lookupFileArg(state, file)));
state.eval(e, *vRoot);
}
else {
/* Construct the installation source from $NIX_PATH. */
auto searchPath = state.getSearchPath();
state.mkAttrs(*vRoot, searchPath.size());
std::unordered_set<std::string> seen;
for (auto & i : searchPath) {
if (i.first == "") continue;
if (seen.count(i.first)) continue;
seen.insert(i.first);
if (!pathExists(i.second)) continue;
mkApp(*state.allocAttr(*vRoot, state.symbols.create(i.first)),
state.getBuiltin("import"),
mkString(*state.allocValue(), i.second));
}
vRoot->attrs->sort();
}
return vRoot;
}
UserEnvElems MixInstallables::evalInstallables(ref<Store> store)
{
UserEnvElems res;
@ -46,15 +81,12 @@ UserEnvElems MixInstallables::evalInstallables(ref<Store> store)
EvalState state({}, store);
Expr * e = state.parseExprFromFile(resolveExprPath(lookupFileArg(state, file)));
Value vRoot;
state.eval(e, vRoot);
auto vRoot = buildSourceExpr(state);
std::map<string, string> autoArgs_;
Bindings & autoArgs(*evalAutoArgs(state, autoArgs_));
Value & v(*findAlongAttrPath(state, installable, autoArgs, vRoot));
Value & v(*findAlongAttrPath(state, installable, autoArgs, *vRoot));
state.forceValue(v);
DrvInfos drvs;

View file

@ -21,10 +21,13 @@ struct UserEnvElem
typedef std::vector<UserEnvElem> UserEnvElems;
struct Value;
class EvalState;
struct MixInstallables : virtual Args
{
Strings installables;
Path file = "<nixpkgs>";
Path file;
MixInstallables()
{
@ -33,6 +36,13 @@ struct MixInstallables : virtual Args
}
UserEnvElems evalInstallables(ref<Store> store);
/* Return a value representing the Nix expression from which we
are installing. This is either the file specified by --file,
or an attribute set constructed from $NIX_PATH, e.g. { nixpkgs
= import ...; bla = import ...; }. */
Value * buildSourceExpr(EvalState & state);
};
}