lix/src/libexpr/get-drvs.cc
Eelco Dolstra 4661282fde * `nix-instantiate ... --arg NAME VALUE': allow arguments to be passed
to functions from the command line.
* nix-build: started removing backticks.
2006-07-28 16:03:28 +00:00

186 lines
5.5 KiB
C++

#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,
const string & attrPath, DrvInfos & drvs, Exprs & doneExprs)
{
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 = attrPath;
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,
const string & pathPrefix, const ATermMap & autoArgs,
DrvInfos & drvs, Exprs & doneExprs)
{
e = evalExpr(state, autoCallFunction(evalExpr(state, e), autoArgs));
/* Process the expression. */
ATermList es;
DrvInfo drv;
if (!getDerivation(state, e, pathPrefix, drvs, doneExprs))
return;
if (matchAttrs(e, es)) {
ATermMap drvMap(ATgetLength(es));
queryAllAttrs(e, drvMap);
for (ATermMap::const_iterator i = drvMap.begin(); i != drvMap.end(); ++i) {
startNest(nest, lvlDebug,
format("evaluating attribute `%1%'") % aterm2String(i->key));
string pathPrefix2 = addToPath(pathPrefix, aterm2String(i->key));
if (getDerivation(state, i->value, pathPrefix2, drvs, doneExprs)) {
/* 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, pathPrefix2, autoArgs, drvs, doneExprs);
}
}
}
return;
}
if (matchList(e, es)) {
int n = 0;
for (ATermIterator i(es); i; ++i, ++n) {
startNest(nest, lvlDebug,
format("evaluating list element"));
string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str());
if (getDerivation(state, *i, pathPrefix2, drvs, doneExprs))
getDerivations(state, *i, pathPrefix2, autoArgs, drvs, doneExprs);
}
return;
}
throw TypeError("expression does not evaluate to a derivation (or a set or list of those)");
}
void getDerivations(EvalState & state, Expr e, const string & pathPrefix,
const ATermMap & autoArgs, DrvInfos & drvs)
{
Exprs doneExprs;
getDerivations(state, e, pathPrefix, autoArgs, drvs, doneExprs);
}