1 files changed, 29 insertions, 13 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 3c899d769253..51680ad62ee2 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -10,6 +10,7 @@
 #include "util.hh"
 #include "value-to-json.hh"
 #include "value-to-xml.hh"
+#include "primops.hh"
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -765,7 +766,7 @@ static void prim_readFile(EvalState & state, const Pos & pos, Value * * args, Va
     string s = readFile(state.checkSourcePath(path));
     if (s.find((char) 0) != string::npos)
         throw Error(format("the contents of the file ‘%1%’ cannot be represented as a Nix string") % path);
-    mkString(v, s.c_str());
+    mkString(v, s.c_str(), context);
 }
 
 
@@ -777,7 +778,6 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va
 
     SearchPath searchPath;
 
-    PathSet context;
     for (unsigned int n = 0; n < args[0]->listSize(); ++n) {
         Value & v2(*args[0]->listElems()[n]);
         state.forceAttrs(v2, pos);
@@ -790,21 +790,23 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va
         i = v2.attrs->find(state.symbols.create("path"));
         if (i == v2.attrs->end())
             throw EvalError(format("attribute ‘path’ missing, at %1%") % pos);
-        string path = state.coerceToPath(pos, *i->value, context);
 
-        searchPath.push_back(std::pair<string, Path>(prefix, state.checkSourcePath(path)));
-    }
+        PathSet context;
+        string path = state.coerceToString(pos, *i->value, context, false, false);
 
-    string path = state.forceStringNoCtx(*args[1], pos);
+        try {
+            state.realiseContext(context);
+        } catch (InvalidPathError & e) {
+            throw EvalError(format("cannot find ‘%1%’, since path ‘%2%’ is not valid, at %3%")
+                % path % e.path % pos);
+        }
 
-    try {
-        state.realiseContext(context);
-    } catch (InvalidPathError & e) {
-        throw EvalError(format("cannot find ‘%1%’, since path ‘%2%’ is not valid, at %3%")
-            % path % e.path % pos);
+        searchPath.emplace_back(prefix, path);
     }
 
-    mkPath(v, state.findFile(searchPath, path, pos).c_str());
+    string path = state.forceStringNoCtx(*args[1], pos);
+
+    mkPath(v, state.checkSourcePath(state.findFile(searchPath, path, pos)).c_str());
 }
 
 /* Read a directory (without . or ..) */
@@ -1703,7 +1705,7 @@ void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v,
     } else
         url = state.forceStringNoCtx(*args[0], pos);
 
-    Path res = downloadFileCached(state.store, url, unpack);
+    Path res = makeDownloader()->downloadCached(state.store, url, unpack);
     mkString(v, res, PathSet({res}));
 }
 
@@ -1725,6 +1727,16 @@ static void prim_fetchTarball(EvalState & state, const Pos & pos, Value * * args
  *************************************************************/
 
 
+RegisterPrimOp::PrimOps * RegisterPrimOp::primOps;
+
+
+RegisterPrimOp::RegisterPrimOp(std::string name, size_t arity, PrimOpFun fun)
+{
+    if (!primOps) primOps = new PrimOps;
+    primOps->emplace_back(name, arity, fun);
+}
+
+
 void EvalState::createBaseEnv()
 {
     baseEnv.up = 0;
@@ -1889,6 +1901,10 @@ void EvalState::createBaseEnv()
     }
     addConstant("__nixPath", v);
 
+    if (RegisterPrimOp::primOps)
+        for (auto & primOp : *RegisterPrimOp::primOps)
+            addPrimOp(std::get<0>(primOp), std::get<1>(primOp), std::get<2>(primOp));
+
     /* Now that we've added all primops, sort the `builtins' set,
        because attribute lookups expect it to be sorted. */
     baseEnv.values[0]->attrs->sort();