From 46a5066b434637dc34a704e208cd53c1be00ce1d Mon Sep 17 00:00:00 2001
From: Georgi Krastev <joro.kr.21@gmail.com>
Date: Sun, 22 Sep 2024 17:22:05 +0300
Subject: [PATCH] Use primary constructor to extract field annotations (#1374)

---
 .../src/main/scala/shapeless/annotation.scala      |  9 ++++-----
 .../src/test/scala/shapeless/annotation.scala      | 14 +++++++++++++-
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/core/shared/src/main/scala/shapeless/annotation.scala b/core/shared/src/main/scala/shapeless/annotation.scala
index 34a542b93..c2add02ea 100644
--- a/core/shared/src/main/scala/shapeless/annotation.scala
+++ b/core/shared/src/main/scala/shapeless/annotation.scala
@@ -382,11 +382,10 @@ class AnnotationMacros(val c: whitebox.Context) extends CaseClassMacros {
 
   private def getAnnotationTreeOptions(tpe: Type, typeAnnotation: Boolean): List[List[(Type, Tree)]] = {
     if (isProduct(tpe)) {
-      val constructorSyms = tpe
-        .member(termNames.CONSTRUCTOR)
-        .asMethod
-        .paramLists
-        .flatten
+      lazy val constructorSyms = tpe
+        .typeSymbol.asClass
+        .primaryConstructor.asMethod
+        .paramLists.iterator.flatten
         .map(sym => nameAsString(sym.name) -> sym)
         .toMap
 
diff --git a/core/shared/src/test/scala/shapeless/annotation.scala b/core/shared/src/test/scala/shapeless/annotation.scala
index 2b315e823..45fb6c492 100644
--- a/core/shared/src/test/scala/shapeless/annotation.scala
+++ b/core/shared/src/test/scala/shapeless/annotation.scala
@@ -16,10 +16,12 @@
 
 package shapeless
 
-import scala.annotation.{ Annotation => saAnnotation }
+import org.junit.Assert._
 import org.junit.Test
 import shapeless.test.{illTyped, typed}
 
+import scala.annotation.{Annotation => saAnnotation}
+
 object AnnotationTestsDefinitions {
 
   case class First() extends saAnnotation
@@ -73,6 +75,10 @@ object AnnotationTestsDefinitions {
   type PosInt = Int @First
   type Email = String @Third('c')
   case class User(age: PosInt, email: Email)
+
+  case class WithSecondaryCtor(i: Int) {
+    def this() = this(0)
+  }
 }
 
 class AnnotationTests {
@@ -233,4 +239,10 @@ class AnnotationTests {
     typed[(First :: HNil) :: (Third :: HNil) :: HNil](user)
     assert(user == (First() :: HNil) :: (Third('c') :: HNil) :: HNil)
   }
+
+  @Test
+  def annotationsWithSecondaryConstructor(): Unit = {
+    val annotations = Annotations[First, WithSecondaryCtor].apply()
+    assertEquals(annotations, None :: HNil)
+  }
 }