1 files changed, 8 insertions, 4 deletions
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 1485dc7fe..ab4d2bc4b 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -4,13 +4,13 @@
 #include "value.hh"
 #include "nixexpr.hh"
 #include "symbol-table.hh"
-#include "hash.hh"
 #include "config.hh"
 
 #include <regex>
 #include <map>
 #include <optional>
 #include <unordered_map>
+#include <mutex>
 
 
 namespace nix {
@@ -74,7 +74,8 @@ public:
         sSystem, sOverrides, sOutputs, sOutputName, sIgnoreNulls,
         sFile, sLine, sColumn, sFunctor, sToString,
         sRight, sWrong, sStructuredAttrs, sBuilder, sArgs,
-        sOutputHash, sOutputHashAlgo, sOutputHashMode;
+        sOutputHash, sOutputHashAlgo, sOutputHashMode,
+        sDescription, sSelf;
     Symbol sDerivationNix;
 
     /* If set, force copying files to the Nix store even if they
@@ -89,6 +90,7 @@ public:
 
     const ref<Store> store;
 
+
 private:
     SrcToStore srcToStore;
 
@@ -151,8 +153,9 @@ public:
     Expr * parseStdin();
 
     /* Evaluate an expression read from the given file to normal
-       form. */
-    void evalFile(const Path & path, Value & v);
+       form. Optionally enforce that the top-level expression is
+       trivial (i.e. doesn't require arbitrary computation). */
+    void evalFile(const Path & path, Value & v, bool mustBeTrivial = false);
 
     void resetFileCache();
 
@@ -324,6 +327,7 @@ private:
 
 
 /* Return a string representing the type of the value `v'. */
+string showType(ValueType type);
 string showType(const Value & v);
 
 /* Decode a context string ‘!<name>!<path>’ into a pair <path,