From b3336b2ce219023ecb3124c147b4ad8372377e6d Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Thu, 17 Oct 2024 10:12:57 +0900
Subject: [PATCH] fix type error if too many `.value`

---
 .../internal/util/appmacro/ContextUtil.scala  | 28 ++++++-
 .../src/sbt-test/tests/many-values/build.sbt  | 79 +++++++++++++++++++
 sbt-app/src/sbt-test/tests/many-values/test   |  1 +
 3 files changed, 106 insertions(+), 2 deletions(-)
 create mode 100644 sbt-app/src/sbt-test/tests/many-values/build.sbt
 create mode 100644 sbt-app/src/sbt-test/tests/many-values/test

diff --git a/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala b/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala
index 99879ec99..070ce99f6 100644
--- a/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala
+++ b/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala
@@ -41,16 +41,40 @@ trait ContextUtil[C <: Quotes & scala.Singleton](val valStart: Int):
   def typed[A: Type](value: Term): Term =
     Typed(value, TypeTree.of[A])
 
+  /**
+   * [[https://github.com/sbt/sbt/issues/7768]]
+   * [[https://github.com/scala/scala3/issues/21779]]
+   */
+  private def exprOfTupleFromSeq(seq: Seq[Expr[Any]])(using q: Quotes): Expr[scala.Tuple] = {
+    def tupleTypeFromSeq(seq: Seq[Expr[Any]]): q.reflect.TypeRepr = {
+      import q.reflect.*
+      val consRef = Symbol.classSymbol("scala.*:").typeRef
+      seq.foldRight(TypeRepr.of[EmptyTuple]) { (expr, ts) =>
+        AppliedType(consRef, expr.asTerm.tpe :: ts :: Nil)
+      }
+    }
+
+    if (seq.sizeIs <= 22) {
+      Expr.ofTupleFromSeq(seq)
+    } else {
+      val tupleTpe = tupleTypeFromSeq(seq)
+      tupleTpe.asType match {
+        case '[tpe] =>
+          '{ Tuple.fromIArray(IArray(${ Varargs(seq) }*)).asInstanceOf[tpe & scala.Tuple] }
+      }
+    }
+  }
+
   def makeTuple(inputs: List[Input]): BuilderResult =
     new BuilderResult:
       override lazy val inputTupleTypeRepr: TypeRepr =
         tupleTypeRepr(inputs.map(_.tpe))
       override def tupleExpr: Expr[Tuple] =
-        Expr.ofTupleFromSeq(inputs.map(_.term.asExpr))
+        exprOfTupleFromSeq(inputs.map(_.term.asExpr))
       override def cacheInputTupleTypeRepr: TypeRepr =
         tupleTypeRepr(inputs.filter(_.isCacheInput).map(_.tpe))
       override def cacheInputExpr(tupleTerm: Term): Expr[Tuple] =
-        Expr.ofTupleFromSeq(inputs.zipWithIndex.flatMap { case (input, idx) =>
+        exprOfTupleFromSeq(inputs.zipWithIndex.flatMap { case (input, idx) =>
           if input.tags.nonEmpty then
             input.tpe.asType match
               case '[a] =>
diff --git a/sbt-app/src/sbt-test/tests/many-values/build.sbt b/sbt-app/src/sbt-test/tests/many-values/build.sbt
new file mode 100644
index 000000000..b210990e3
--- /dev/null
+++ b/sbt-app/src/sbt-test/tests/many-values/build.sbt
@@ -0,0 +1,79 @@
+// https://github.com/sbt/sbt/issues/7768
+
+val a1 = settingKey[Seq[Int]]("")
+val a2 = settingKey[Int]("")
+val a3 = settingKey[Int]("")
+val a4 = settingKey[Int]("")
+val a5 = settingKey[Int]("")
+val a6 = settingKey[Int]("")
+val a7 = settingKey[Int]("")
+val a8 = settingKey[Int]("")
+val a9 = settingKey[Int]("")
+val a10 = settingKey[Int]("")
+val a11 = settingKey[Int]("")
+val a12 = settingKey[Int]("")
+val a13 = settingKey[Int]("")
+val a14 = settingKey[Int]("")
+val a15 = settingKey[Int]("")
+val a16 = settingKey[Int]("")
+val a17 = settingKey[Int]("")
+val a18 = settingKey[Int]("")
+val a19 = settingKey[Int]("")
+val a20 = settingKey[Int]("")
+val a21 = settingKey[Int]("")
+val a22 = settingKey[Int]("")
+val a23 = settingKey[Int]("")
+
+a1 := List(1)
+a2 := 2
+a3 := 3
+a4 := 4
+a5 := 5
+a6 := 6
+a7 := 7
+a8 := 8
+a9 := 9
+a10 := 10
+a11 := 11
+a12 := 12
+a13 := 13
+a14 := 14
+a15 := 15
+a16 := 16
+a17 := 17
+a18 := 18
+a19 := 19
+a20 := 20
+a21 := 21
+a22 := 22
+a23 := 23
+
+TaskKey[Unit]("check") := {
+  val sum = (
+    a1.value ++ List(
+      a2.value,
+      a3.value,
+      a4.value,
+      a5.value,
+      a6.value,
+      a7.value,
+      a8.value,
+      a9.value,
+      a10.value,
+      a11.value,
+      a12.value,
+      a13.value,
+      a14.value,
+      a15.value,
+      a16.value,
+      a17.value,
+      a18.value,
+      a19.value,
+      a20.value,
+      a21.value,
+      a22.value,
+      a23.value,
+    )
+  ).sum
+  assert(sum == 276, sum)
+}
diff --git a/sbt-app/src/sbt-test/tests/many-values/test b/sbt-app/src/sbt-test/tests/many-values/test
new file mode 100644
index 000000000..15675b169
--- /dev/null
+++ b/sbt-app/src/sbt-test/tests/many-values/test
@@ -0,0 +1 @@
+> check