From 023912def37c8db64dec0339d39f2535e0d79e78 Mon Sep 17 00:00:00 2001
From: Ben Burdette <bburdette@gmail.com>
Date: Wed, 24 Jun 2020 13:46:25 -0600
Subject: [PATCH] convenience form of addTrace

---
 src/libexpr/eval.cc    |  6 +++---
 src/libexpr/primops.cc | 12 ++++++------
 src/libutil/error.hh   |  6 ++++++
 src/nix-env/nix-env.cc |  4 ++--
 src/nix/search.cc      |  2 +-
 5 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 3fd8aa285..1cbbb7ade 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -594,17 +594,17 @@ LocalNoInlineNoReturn(void throwUndefinedVarError(const Pos & pos, const char *
 
 LocalNoInline(void addErrorTrace(Error & e, const char * s, const string & s2))
 {
-    e.addTrace(std::nullopt, hintfmt(s) % s2);
+    e.addTrace(std::nullopt, s, s2);
 }
 
 LocalNoInline(void addErrorTrace(Error & e, const Pos & pos, const char * s, const ExprLambda & fun))
 {
-    e.addTrace(pos, hintfmt(s) % fun.showNamePos());
+    e.addTrace(pos, s, fun.showNamePos());
 }
 
 LocalNoInline(void addErrorTrace(Error & e, const Pos & pos, const char * s, const string & s2))
 {
-    e.addTrace(pos, hintfmt(s) % s2);
+    e.addTrace(pos, s, s2);
 }
 
 
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 6f7a691cd..4cc3718e3 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -239,13 +239,13 @@ void prim_exec(EvalState & state, const Pos & pos, Value * * args, Value & v)
     try {
         parsed = state.parseExprFromString(output, pos.file);
     } catch (Error & e) {
-        e.addTrace(pos, hintfmt("While parsing the output from '%1%'", program));
+        e.addTrace(pos, "While parsing the output from '%1%'", program);
         throw;
     }
     try {
         state.eval(parsed, v);
     } catch (Error & e) {
-        e.addTrace(pos, hintfmt("While evaluating the output from '%1%'", program));
+        e.addTrace(pos, "While evaluating the output from '%1%'", program);
         throw;
     }
 }
@@ -472,7 +472,7 @@ static void prim_addErrorContext(EvalState & state, const Pos & pos, Value * * a
     } catch (Error & e) {
         PathSet context;
         // TODO: is this right, include this pos??  Test it.  esp with LOC.
-        e.addTrace(pos, hintfmt("%1%") % state.coerceToString(pos, *args[0], context));
+        e.addTrace(pos, "%1%", state.coerceToString(pos, *args[0], context));
         throw;
     }
 }
@@ -564,7 +564,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
     try {
         drvName = state.forceStringNoCtx(*attr->value, pos);
     } catch (Error & e) {
-        e.addTrace(posDrvName, hintfmt("while evaluating the derivation attribute 'name'"));
+        e.addTrace(posDrvName, "while evaluating the derivation attribute 'name'");
         throw;
     }
 
@@ -698,8 +698,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
 
         } catch (Error & e) {
             e.addTrace(posDrvName, 
-                hintfmt("while evaluating the attribute '%1%' of the derivation '%2%'",
-                    key, drvName));
+                "while evaluating the attribute '%1%' of the derivation '%2%'",
+                key, drvName);
             throw;
         }
     }
diff --git a/src/libutil/error.hh b/src/libutil/error.hh
index 3879d9b5f..09fc57fee 100644
--- a/src/libutil/error.hh
+++ b/src/libutil/error.hh
@@ -166,6 +166,12 @@ public:
     const string & msg() const { return calcWhat(); }
     const ErrorInfo & info() { calcWhat(); return err; }
 
+    template<typename... Args>
+    BaseError & addTrace(std::optional<ErrPos> e, const string &fs, const Args & ... args)
+    {
+        return addTrace(e, hintfmt(fs, args...));
+    }
+
     BaseError & addTrace(std::optional<ErrPos> e, hintformat hint);
 };
 
diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index f5dfbf9f6..c992b7d74 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -593,7 +593,7 @@ static void upgradeDerivations(Globals & globals,
                 } else newElems.push_back(i);
 
             } catch (Error & e) {
-                e.addTrace(std::nullopt, hintfmt("while trying to find an upgrade for '%s'", i.queryName()));
+                e.addTrace(std::nullopt, "while trying to find an upgrade for '%s'", i.queryName());
                 throw;
             }
         }
@@ -1185,7 +1185,7 @@ static void opQuery(Globals & globals, Strings opFlags, Strings opArgs)
         } catch (AssertionError & e) {
             printMsg(lvlTalkative, "skipping derivation named '%1%' which gives an assertion failure", i.queryName());
         } catch (Error & e) {
-            e.addTrace(std::nullopt, hintfmt("while querying the derivation named '%1%'", i.queryName()));
+            e.addTrace(std::nullopt, "while querying the derivation named '%1%'", i.queryName());
             throw;
         }
     }
diff --git a/src/nix/search.cc b/src/nix/search.cc
index d9c730796..93c3f3f83 100644
--- a/src/nix/search.cc
+++ b/src/nix/search.cc
@@ -216,7 +216,7 @@ struct CmdSearch : SourceExprCommand, MixJSON
             } catch (AssertionError & e) {
             } catch (Error & e) {
                 if (!toplevel) {
-                    e.addTrace(std::nullopt, hintfmt("While evaluating the attribute '%s'", attrPath));
+                    e.addTrace(std::nullopt, "While evaluating the attribute '%s'", attrPath);
                     throw;
                 }
             }