primops/fromJSON: add error position in case of parse error

This makes it easier to track down where invalid JSON was passed to `builtins.fromJSON`.
NixOS · Dec 11, 2020 · 4aa83e9 · 4aa83e9
1 parent c6a1bcd
commit 4aa83e9
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
@@ -1621,7 +1621,13 @@ static RegisterPrimOp primop_toJSON({
 static void prim_fromJSON(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
     string s = state.forceStringNoCtx(*args[0], pos);
-    parseJSON(state, s, v);
+    try {
+        parseJSON(state, s, v);
+    } catch (JSONParseError &e) {
+        auto info = e.info();
+        info.errPos = pos;
+        throw EvalError(info);
+    }
 }
 
 static RegisterPrimOp primop_fromJSON({