lix/src/libexpr/get-drvs.cc

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#include "get-drvs.hh"
#include "nixexpr-ast.hh"
typedef set<Expr> Exprs;
static bool getDerivation(EvalState & state, Expr e,
DrvInfos & drvs, Exprs & doneExprs)
{
ATermList es;
e = evalExpr(state, e);
if (!matchAttrs(e, es)) return false;
ATermMap attrs;
queryAllAttrs(e, attrs, false);
Expr a = attrs.get("type");
if (!a || evalString(state, a) != "derivation") return false;
/* Remove spurious duplicates (e.g., an attribute set like `rec {
x = derivation {...}; y = x;}'. */
if (doneExprs.find(e) != doneExprs.end()) return true;
doneExprs.insert(e);
DrvInfo drv;
a = attrs.get("name");
if (!a) throw badTerm("derivation name missing", e);
drv.name = evalString(state, a);
a = attrs.get("system");
if (!a)
drv.system = "unknown";
else
drv.system = evalString(state, a);
drv.attrs = attrs;
drvs.push_back(drv);
return true;
}
bool getDerivation(EvalState & state, Expr e, DrvInfo & drv)
{
Exprs doneExprs;
DrvInfos drvs;
bool result = getDerivation(state, e, drvs, doneExprs);
if (result) drv = drvs.front();
return result;
}
static void getDerivations(EvalState & state, Expr e,
DrvInfos & drvs, Exprs & doneExprs)
{
ATermList es;
DrvInfo drv;
e = evalExpr(state, e);
if (getDerivation(state, e, drv)) {
drvs.push_back(drv);
return;
}
if (matchAttrs(e, es)) {
ATermMap drvMap;
queryAllAttrs(e, drvMap);
for (ATermIterator i(drvMap.keys()); i; ++i) {
debug(format("evaluating attribute `%1%'") % aterm2String(*i));
getDerivation(state, drvMap.get(*i), drvs, doneExprs);
}
return;
}
if (matchList(e, es)) {
for (ATermIterator i(es); i; ++i) {
debug(format("evaluating list element"));
if (!getDerivation(state, *i, drvs, doneExprs))
getDerivations(state, *i, drvs, doneExprs);
}
return;
}
ATermList formals;
ATerm body, pos;
if (matchFunction(e, formals, body, pos)) {
for (ATermIterator i(formals); i; ++i) {
Expr name, def;
if (matchNoDefFormal(*i, name))
throw Error(format("expression evaluates to a function with no-default arguments (`%1%')")
% aterm2String(name));
else if (!matchDefFormal(*i, name, def))
abort(); /* can't happen */
}
getDerivations(state, makeCall(e, makeAttrs(ATermMap())), drvs, doneExprs);
return;
}
throw Error("expression does not evaluate to a derivation (or a set or list of those)");
}
void getDerivations(EvalState & state, Expr e, DrvInfos & drvs)
{
Exprs doneExprs;
getDerivations(state, e, drvs, doneExprs);
}