From cbfbf71e0821fd79ae4837e7fe03c051437f43dd Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 2 Mar 2020 17:22:31 +0100
Subject: [PATCH] Use callFunction() with an array for some calls with arity >
 1

---
 src/libexpr/primops.cc | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 8a573f35c..9b166d63c 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -1883,9 +1883,6 @@ static void addPath(
             Value arg1;
             mkString(arg1, path);
 
-            Value fun2;
-            state.callFunction(*filterFun, arg1, fun2, noPos);
-
             Value arg2;
             mkString(arg2,
                 S_ISREG(st.st_mode) ? "regular" :
@@ -1893,8 +1890,9 @@ static void addPath(
                 S_ISLNK(st.st_mode) ? "symlink" :
                 "unknown" /* not supported, will fail! */);
 
+            Value * args []{&arg1, &arg2};
             Value res;
-            state.callFunction(fun2, arg2, res, noPos);
+            state.callFunction(*filterFun, 2, args, res, pos);
 
             return state.forceBool(res, pos);
         }) : defaultPathFilter;
@@ -2695,10 +2693,9 @@ static void prim_foldlStrict(EvalState & state, const Pos & pos, Value * * args,
         Value * vCur = args[1];
 
         for (unsigned int n = 0; n < args[2]->listSize(); ++n) {
-            Value vTmp;
-            state.callFunction(*args[0], *vCur, vTmp, pos);
+            Value * vs []{vCur, args[2]->listElems()[n]};
             vCur = n == args[2]->listSize() - 1 ? &v : state.allocValue();
-            state.callFunction(vTmp, *args[2]->listElems()[n], *vCur, pos);
+            state.callFunction(*args[0], 2, vs, *vCur, pos);
         }
         state.forceValue(v, pos);
     } else {
@@ -2819,17 +2816,16 @@ static void prim_sort(EvalState & state, const Pos & pos, Value * * args, Value
         v.listElems()[n] = args[1]->listElems()[n];
     }
 
-
     auto comparator = [&](Value * a, Value * b) {
         /* Optimization: if the comparator is lessThan, bypass
            callFunction. */
         if (args[0]->isPrimOp() && args[0]->primOp->fun == prim_lessThan)
             return CompareValues()(a, b);
 
-        Value vTmp1, vTmp2;
-        state.callFunction(*args[0], *a, vTmp1, pos);
-        state.callFunction(vTmp1, *b, vTmp2, pos);
-        return state.forceBool(vTmp2, pos);
+        Value * vs[] = {a, b};
+        Value vBool;
+        state.callFunction(*args[0], 2, vs, vBool, pos);
+        return state.forceBool(vBool, pos);
     };
 
     /* FIXME: std::sort can segfault if the comparator is not a strict