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#include "get-drvs.hh"
#include "nixexpr-ast.hh"
#include "util.hh"
namespace nix {
string DrvInfo::queryDrvPath(EvalState & state) const
{
if (drvPath == "") {
Expr a = attrs->get(toATerm("drvPath"));
/* Backwards compatibility hack with user environments made by
Nix <= 0.10: these contain illegal Path("") expressions. */
ATerm t;
if (a && matchPath(evalExpr(state, a), t))
return aterm2String(t);
PathSet context;
(string &) drvPath = a ? coerceToPath(state, a, context) : "";
}
return drvPath;
}
string DrvInfo::queryOutPath(EvalState & state) const
{
if (outPath == "") {
Expr a = attrs->get(toATerm("outPath"));
if (!a) throw TypeError("output path missing");
PathSet context;
(string &) outPath = coerceToPath(state, a, context);
}
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;
queryAllAttrs(evalExpr(state, a), attrs2);
for (ATermMap::const_iterator i = attrs2.begin(); i != attrs2.end(); ++i) {
Expr e = evalExpr(state, i->value);
string s;
PathSet context;
if (matchStr(e, s, context))
meta[aterm2String(i->key)] = s;
/* For future compatibility, ignore attribute values that are
not strings. */
}
return meta;
}
string DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
{
/* !!! evaluates all meta attributes => inefficient */
MetaInfo meta = queryMetaInfo(state);
MetaInfo::iterator i = meta.find(name);
return i == meta.end() ? "" : i->second;
}
void DrvInfo::setMetaInfo(const MetaInfo & meta)
{
ATermMap metaAttrs;
for (MetaInfo::const_iterator i = meta.begin(); i != meta.end(); ++i)
metaAttrs.set(toATerm(i->first),
makeAttrRHS(makeStr(i->second), makeNoPos()));
attrs->set(toATerm("meta"), makeAttrs(metaAttrs));
}
/* 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;
boost::shared_ptr<ATermMap> attrs(new ATermMap());
queryAllAttrs(e, *attrs, false);
Expr a = attrs->get(toATerm("type"));
if (!a || evalStringNoCtx(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 = evalStringNoCtx(state, a);
a = attrs->get(toATerm("system"));
if (!a)
drv.system = "unknown";
else
drv.system = evalStringNoCtx(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);
/* !!! undocumented hackery to support combining channels in
nix-env.cc. */
bool combineChannels = drvMap.get(toATerm("_combineChannels"));
/* Consider the attributes in sorted order to get more
deterministic behaviour in nix-env operations (e.g. when
there are names clashes between derivations, the derivation
bound to the attribute with the "lower" name should take
precedence). */
typedef std::map<string, Expr> AttrsSorted;
AttrsSorted attrsSorted;
foreach (ATermMap::const_iterator, i, drvMap)
attrsSorted[aterm2String(i->key)] = i->value;
foreach (AttrsSorted::iterator, i, attrsSorted) {
startNest(nest, lvlDebug, format("evaluating attribute `%1%'") % i->first);
string pathPrefix2 = addToPath(pathPrefix, i->first);
if (combineChannels)
getDerivations(state, i->second, pathPrefix2, autoArgs, drvs, doneExprs);
else if (getDerivation(state, i->second, 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->second), e2;
if (matchAttrs(e, es)) {
ATermMap attrs(ATgetLength(es));
queryAllAttrs(e, attrs, false);
if (((e2 = attrs.get(toATerm("recurseForDerivations")))
&& 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);
}
}
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