From 4e340a983f928973d3915455d46a4bbadbc3269c Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 25 Nov 2014 10:23:36 +0100
Subject: [PATCH] forceString(): Accept pos argument

---
 src/libexpr/eval.cc    | 4 ++--
 src/libexpr/eval.hh    | 2 +-
 src/libexpr/primops.cc | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 81774974a..ebb28021c 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -1257,9 +1257,9 @@ void copyContext(const Value & v, PathSet & context)
 }
 
 
-string EvalState::forceString(Value & v, PathSet & context)
+string EvalState::forceString(Value & v, PathSet & context, const Pos & pos)
 {
-    string s = forceString(v);
+    string s = forceString(v, pos);
     copyContext(v, context);
     return s;
 }
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index d066f7fd5..8bf65c2c5 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -200,7 +200,7 @@ public:
     inline void forceList(Value & v, const Pos & pos);
     void forceFunction(Value & v, const Pos & pos); // either lambda or primop
     string forceString(Value & v, const Pos & pos = noPos);
-    string forceString(Value & v, PathSet & context);
+    string forceString(Value & v, PathSet & context, const Pos & pos = noPos);
     string forceStringNoCtx(Value & v, const Pos & pos = noPos);
 
     /* Return true iff the value `v' denotes a derivation (i.e. a
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index e6edffa46..ed50c8091 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -870,7 +870,7 @@ static void prim_toFile(EvalState & state, const Pos & pos, Value * * args, Valu
 {
     PathSet context;
     string name = state.forceStringNoCtx(*args[0], pos);
-    string contents = state.forceString(*args[1], context);
+    string contents = state.forceString(*args[1], context, pos);
 
     PathSet refs;
 
@@ -1427,7 +1427,7 @@ static void prim_hashString(EvalState & state, const Pos & pos, Value * * args,
       throw Error(format("unknown hash type ‘%1%’, at %2%") % type % pos);
 
     PathSet context; // discarded
-    string s = state.forceString(*args[1], context);
+    string s = state.forceString(*args[1], context, pos);
 
     mkString(v, printHash(hashString(ht, s)), context);
 };