From 7bd9eef772540c37c7a1681c4fa2ed2493906484 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Thu, 15 May 2025 16:21:02 -0400
Subject: [PATCH] Deduplicate the goal creation functions

The weak reference logic is the same in both these cases, and if/when I
get rid `addWantedOutputs`, also in the `DerivationGoal` case.
---
 src/libstore/build/worker.cc                  | 28 ++++++++-----------
 .../include/nix/store/build/worker.hh         |  3 ++
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc
index dd3692f41..6b1e3c0f4 100644
--- a/src/libstore/build/worker.cc
+++ b/src/libstore/build/worker.cc
@@ -41,6 +41,16 @@ Worker::~Worker()
     assert(expectedNarSize == 0);
 }
 
+template<class G, typename... Args>
+std::shared_ptr<G> Worker::initGoalIfNeeded(std::weak_ptr<G> & goal_weak, Args && ...args)
+{
+    if (auto goal = goal_weak.lock()) return goal;
+
+    auto goal = std::make_shared<G>(args...);
+    goal_weak = goal;
+    wakeUp(goal);
+    return goal;
+}
 
 std::shared_ptr<DerivationGoal> Worker::makeDerivationGoalCommon(
     const StorePath & drvPath,
@@ -79,27 +89,13 @@ std::shared_ptr<DerivationGoal> Worker::makeBasicDerivationGoal(const StorePath
 
 std::shared_ptr<PathSubstitutionGoal> Worker::makePathSubstitutionGoal(const StorePath & path, RepairFlag repair, std::optional<ContentAddress> ca)
 {
-    std::weak_ptr<PathSubstitutionGoal> & goal_weak = substitutionGoals[path];
-    auto goal = goal_weak.lock(); // FIXME
-    if (!goal) {
-        goal = std::make_shared<PathSubstitutionGoal>(path, *this, repair, ca);
-        goal_weak = goal;
-        wakeUp(goal);
-    }
-    return goal;
+    return initGoalIfNeeded(substitutionGoals[path], path, *this, repair, ca);
 }
 
 
 std::shared_ptr<DrvOutputSubstitutionGoal> Worker::makeDrvOutputSubstitutionGoal(const DrvOutput& id, RepairFlag repair, std::optional<ContentAddress> ca)
 {
-    std::weak_ptr<DrvOutputSubstitutionGoal> & goal_weak = drvOutputSubstitutionGoals[id];
-    auto goal = goal_weak.lock(); // FIXME
-    if (!goal) {
-        goal = std::make_shared<DrvOutputSubstitutionGoal>(id, *this, repair, ca);
-        goal_weak = goal;
-        wakeUp(goal);
-    }
-    return goal;
+    return initGoalIfNeeded(drvOutputSubstitutionGoals[id], id, *this, repair, ca);
 }
 
 
diff --git a/src/libstore/include/nix/store/build/worker.hh b/src/libstore/include/nix/store/build/worker.hh
index 7e03a0c2f..adbaa4027 100644
--- a/src/libstore/include/nix/store/build/worker.hh
+++ b/src/libstore/include/nix/store/build/worker.hh
@@ -196,6 +196,9 @@ public:
      * @ref DerivationGoal "derivation goal"
      */
 private:
+    template<class G, typename... Args>
+    std::shared_ptr<G> initGoalIfNeeded(std::weak_ptr<G> & goal_weak, Args && ...args);
+
     std::shared_ptr<DerivationGoal> makeDerivationGoalCommon(
         const StorePath & drvPath, const OutputsSpec & wantedOutputs,
         std::function<std::shared_ptr<DerivationGoal>()> mkDrvGoal);