Introduce Worker::makeGoal

This takes a `DerivedPath` so the caller doesn't need to care about
which sort of goal does what.

src/libstore/build/entry-points.cc

@@ -10,16 +10,8 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
     Worker worker(*this, evalStore ? *evalStore : *this);
 
     Goals goals;
-    for (const auto & br : reqs) {
+    for (auto & br : reqs)
-        std::visit(overloaded {
+        goals.insert(worker.makeGoal(br, buildMode));
-            [&](const DerivedPath::Built & bfd) {
-                goals.insert(worker.makeDerivationGoal(bfd.drvPath, bfd.outputs, buildMode));
-            },
-            [&](const DerivedPath::Opaque & bo) {
-                goals.insert(worker.makePathSubstitutionGoal(bo.path, buildMode == bmRepair ? Repair : NoRepair));
-            },
-        }, br.raw());
-    }
 
     worker.run(goals);
 
@@ -55,16 +47,8 @@ std::vector<BuildResult> Store::buildPathsWithResults(
     Worker worker(*this, evalStore ? *evalStore : *this);
 
     Goals goals;
-    for (const auto & br : reqs) {
+    for (const auto & br : reqs)
-        std::visit(overloaded {
+        goals.insert(worker.makeGoal(br, buildMode));
-            [&](const DerivedPath::Built & bfd) {
-                goals.insert(worker.makeDerivationGoal(bfd.drvPath, bfd.outputs, buildMode));
-            },
-            [&](const DerivedPath::Opaque & bo) {
-                goals.insert(worker.makePathSubstitutionGoal(bo.path, buildMode == bmRepair ? Repair : NoRepair));
-            },
-        }, br.raw());
-    }
 
     worker.run(goals);
 

src/libstore/build/worker.cc

@@ -92,6 +92,7 @@ std::shared_ptr<PathSubstitutionGoal> Worker::makePathSubstitutionGoal(const Sto
     return goal;
 }
 
+
 std::shared_ptr<DrvOutputSubstitutionGoal> Worker::makeDrvOutputSubstitutionGoal(const DrvOutput& id, RepairFlag repair, std::optional<ContentAddress> ca)
 {
     std::weak_ptr<DrvOutputSubstitutionGoal> & goal_weak = drvOutputSubstitutionGoals[id];
@@ -104,6 +105,20 @@ std::shared_ptr<DrvOutputSubstitutionGoal> Worker::makeDrvOutputSubstitutionGoal
     return goal;
 }
 
+
+GoalPtr Worker::makeGoal(const DerivedPath & req, BuildMode buildMode)
+{
+    return std::visit(overloaded {
+        [&](const DerivedPath::Built & bfd) -> GoalPtr {
+            return makeDerivationGoal(bfd.drvPath, bfd.outputs, buildMode);
+        },
+        [&](const DerivedPath::Opaque & bo) -> GoalPtr {
+            return makePathSubstitutionGoal(bo.path, buildMode == bmRepair ? Repair : NoRepair);
+        },
+    }, req.raw());
+}
+
+
 template<typename K, typename G>
 static void removeGoal(std::shared_ptr<G> goal, std::map<K, std::weak_ptr<G>> & goalMap)
 {

src/libstore/build/worker.hh

@@ -181,7 +181,7 @@ public:
      */
 
     /**
-     * derivation goal
+     * @ref DerivationGoal "derivation goal"
      */
 private:
     std::shared_ptr<DerivationGoal> makeDerivationGoalCommon(
@@ -196,11 +196,19 @@ public:
         const OutputsSpec & wantedOutputs, BuildMode buildMode = bmNormal);
 
     /**
-     * substitution goal
+     * @ref SubstitutionGoal "substitution goal"
      */
     std::shared_ptr<PathSubstitutionGoal> makePathSubstitutionGoal(const StorePath & storePath, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
     std::shared_ptr<DrvOutputSubstitutionGoal> makeDrvOutputSubstitutionGoal(const DrvOutput & id, RepairFlag repair = NoRepair, std::optional<ContentAddress> ca = std::nullopt);
 
+    /**
+     * Make a goal corresponding to the `DerivedPath`.
+     *
+     * It will be a `DerivationGoal` for a `DerivedPath::Built` or
+     * a `SubstitutionGoal` for a `DerivedPath::Opaque`.
+     */
+    GoalPtr makeGoal(const DerivedPath & req, BuildMode buildMode = bmNormal);
+
     /**
      * Remove a dead goal.
      */