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#include "get-drvs.hh"
#include "nixexpr-ast.hh"
string DrvInfo::queryDrvPath(EvalState & state) const
{
if (drvPath == "") {
Expr a = attrs->get(toATerm("drvPath"));
(string &) drvPath = a ? evalPath(state, a) : "";
}
return drvPath;
}
string DrvInfo::queryOutPath(EvalState & state) const
{
if (outPath == "") {
Expr a = attrs->get(toATerm("outPath"));
if (!a) throw TypeError("output path missing");
(string &) outPath = evalPath(state, a);
}
return outPath;
}
MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
{
MetaInfo meta;
Expr a = attrs->get(toATerm("meta"));
if (!a) return meta; /* fine, empty meta information */
ATermMap attrs2(16); /* !!! */
queryAllAttrs(evalExpr(state, a), attrs2);
for (ATermMap::const_iterator i = attrs2.begin(); i != attrs2.end(); ++i) {
ATerm s = coerceToString(evalExpr(state, i->value));
if (s)
meta[aterm2String(i->key)] = aterm2String(s);
/* For future compatibility, ignore attribute values that are
not strings. */
}
return meta;
}
/* Cache for already evaluated derivations. Usually putting ATerms in
a STL container is unsafe (they're not scanning for GC roots), but
here it doesn't matter; everything in this set is reachable from
the stack as well. */
typedef set<Expr> Exprs;
/* Evaluate expression `e'. If it evaluates to an attribute set of
type `derivation', then put information about it in `drvs' (unless
it's already in `doneExprs'). The result boolean indicates whether
it makes sense for the caller to recursively search for derivations
in `e'. */
static bool getDerivation(EvalState & state, Expr e,
DrvInfos & drvs, Exprs & doneExprs, string attributeName)
{
try {
ATermList es;
e = evalExpr(state, e);
if (!matchAttrs(e, es)) return true;
shared_ptr<ATermMap> attrs(new ATermMap(32)); /* !!! */
queryAllAttrs(e, *attrs, false);
Expr a = attrs->get(toATerm("type"));
if (!a || evalString(state, a) != "derivation") return true;
/* Remove spurious duplicates (e.g., an attribute set like
`rec { x = derivation {...}; y = x;}'. */
if (doneExprs.find(e) != doneExprs.end()) return false;
doneExprs.insert(e);
DrvInfo drv;
a = attrs->get(toATerm("name"));
/* !!! We really would like to have a decent back trace here. */
if (!a) throw TypeError("derivation name missing");
drv.name = evalString(state, a);
a = attrs->get(toATerm("system"));
if (!a)
drv.system = "unknown";
else
drv.system = evalString(state, a);
drv.attrs = attrs;
drv.attrPath = attributeName;
drvs.push_back(drv);
return false;
} catch (AssertionError & e) {
return false;
}
}
bool getDerivation(EvalState & state, Expr e, DrvInfo & drv)
{
Exprs doneExprs;
DrvInfos drvs;
getDerivation(state, e, drvs, doneExprs, "");
if (drvs.size() != 1) return false;
drv = drvs.front();
return true;
}
static string addToPath(const string & s1, const string & s2)
{
return s1.empty() ? s2 : s1 + "." + s2;
}
static void getDerivations(EvalState & state, Expr e,
DrvInfos & drvs, Exprs & doneExprs, const string & attrPath,
const string & pathTaken)
{
/* Automatically call functions for which each argument has a
default value. */
ATermList formals;
ATerm body, pos;
if (matchFunction(e, formals, body, pos)) {
for (ATermIterator i(formals); i; ++i) {
Expr name, def; ATerm values, def2;
if (!matchFormal(*i, name, values, def2)) abort();
if (!matchDefaultValue(def2, def))
throw TypeError(format("cannot auto-call a function that has an argument without a default value (`%1%')")
% aterm2String(name));
}
getDerivations(state,
makeCall(e, makeAttrs(ATermMap(0))),
drvs, doneExprs, attrPath, pathTaken);
return;
}
/* Parse the start of attrPath. */
enum { apNone, apAttr, apIndex } apType;
string attrPathRest;
string attr;
int attrIndex;
Error attrError =
Error(format("attribute selection path `%1%' does not match expression") % attrPath);
if (attrPath.empty())
apType = apNone;
else {
string::size_type dot = attrPath.find(".");
if (dot == string::npos) {
attrPathRest = "";
attr = attrPath;
} else {
attrPathRest = string(attrPath, dot + 1);
attr = string(attrPath, 0, dot);
}
apType = apAttr;
if (string2Int(attr, attrIndex)) apType = apIndex;
}
/* Process the expression. */
ATermList es;
DrvInfo drv;
if (!getDerivation(state, e, drvs, doneExprs, pathTaken)) {
if (apType != apNone) throw attrError;
return;
}
e = evalExpr(state, e);
if (matchAttrs(e, es)) {
if (apType != apNone && apType != apAttr) throw attrError;
ATermMap drvMap(ATgetLength(es));
queryAllAttrs(e, drvMap);
if (apType == apNone) {
for (ATermMap::const_iterator i = drvMap.begin(); i != drvMap.end(); ++i) {
startNest(nest, lvlDebug,
format("evaluating attribute `%1%'") % aterm2String(i->key));
string pathTaken2 = addToPath(pathTaken, aterm2String(i->key));
if (getDerivation(state, i->value, drvs, doneExprs, pathTaken2)) {
/* If the value of this attribute is itself an
attribute set, should we recurse into it?
=> Only if it has a `recurseForDerivations = true'
attribute. */
ATermList es;
Expr e = evalExpr(state, i->value);
if (matchAttrs(e, es)) {
ATermMap attrs(ATgetLength(es));
queryAllAttrs(e, attrs, false);
Expr e2 = attrs.get(toATerm("recurseForDerivations"));
if (e2 && evalBool(state, e2))
getDerivations(state, e, drvs, doneExprs, attrPathRest, pathTaken2);
}
}
}
} else {
Expr e2 = drvMap.get(toATerm(attr));
if (!e2) throw Error(format("attribute `%1%' in selection path not found") % attr);
startNest(nest, lvlDebug,
format("evaluating attribute `%1%'") % attr);
string pathTaken2 = addToPath(pathTaken, attr);
getDerivation(state, e2, drvs, doneExprs, pathTaken2);
if (!attrPath.empty())
getDerivations(state, e2, drvs, doneExprs, attrPathRest, pathTaken2);
}
return;
}
if (matchList(e, es)) {
if (apType != apNone && apType != apIndex) throw attrError;
if (apType == apNone) {
int n = 0;
for (ATermIterator i(es); i; ++i, ++n) {
startNest(nest, lvlDebug,
format("evaluating list element"));
string pathTaken2 = addToPath(pathTaken, (format("%1%") % n).str());
if (getDerivation(state, *i, drvs, doneExprs, pathTaken2))
getDerivations(state, *i, drvs, doneExprs, attrPathRest, pathTaken2);
}
} else {
Expr e2 = ATelementAt(es, attrIndex);
if (!e2) throw Error(format("list index %1% in selection path not found") % attrIndex);
startNest(nest, lvlDebug,
format("evaluating list element"));
string pathTaken2 = addToPath(pathTaken, (format("%1%") % attrIndex).str());
if (getDerivation(state, e2, drvs, doneExprs, pathTaken2))
getDerivations(state, e2, drvs, doneExprs, attrPathRest, pathTaken2);
}
return;
}
throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
}
void getDerivations(EvalState & state, Expr e, DrvInfos & drvs,
const string & attrPath)
{
Exprs doneExprs;
getDerivations(state, e, drvs, doneExprs, attrPath, "");
}
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