Add check for parents in Quotes (#19842)

compiler/src/dotty/tools/dotc/transform/TreeChecker.scala

@@ -198,6 +198,17 @@ object TreeChecker {
     }
   }.apply(tp0)
 
+  def checkParents(sym: ClassSymbol, parents: List[tpd.Tree])(using Context): Unit =
+    val symbolParents = sym.classInfo.parents.map(_.dealias.typeSymbol)
+    val treeParents = parents.map(_.tpe.dealias.typeSymbol)
+    assert(symbolParents == treeParents,
+      i"""Parents of class symbol differs from the parents in the tree for $sym
+          |
+          |Parents in symbol: $symbolParents
+          |Parents in tree: $treeParents
+          |""".stripMargin)
+  end checkParents
+
   /** Run some additional checks on the nodes of the trees.  Specifically:
    *
    *    - TypeTree can only appear in TypeApply args, New, Typed tpt, Closure
@@ -570,14 +581,7 @@ object TreeChecker {
       assert(ctx.owner.isClass)
       val sym = ctx.owner.asClass
       if !sym.isPrimitiveValueClass then
-        val symbolParents = sym.classInfo.parents.map(_.dealias.typeSymbol)
-        val treeParents = impl.parents.map(_.tpe.dealias.typeSymbol)
-        assert(symbolParents == treeParents,
-        i"""Parents of class symbol differs from the parents in the tree for $sym
-            |
-            |Parents in symbol: $symbolParents
-            |Parents in tree: $treeParents
-            |""".stripMargin)
+        TreeChecker.checkParents(sym, impl.parents)
     }
 
     override def typedTypeDef(tdef: untpd.TypeDef, sym: Symbol)(using Context): Tree = {

compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

@@ -24,6 +24,7 @@ import scala.quoted.runtime.impl.printers.*
 
 import scala.reflect.TypeTest
 import dotty.tools.dotc.core.NameKinds.ExceptionBinderName
+import dotty.tools.dotc.transform.TreeChecker
 
 object QuotesImpl {
 
@@ -253,6 +254,7 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
         (cdef.name.toString, cdef.constructor, cdef.parents, cdef.self, rhs.body)
 
       def module(module: Symbol, parents: List[Tree /* Term | TypeTree */], body: List[Statement]): (ValDef, ClassDef) = {
+        if xCheckMacro then TreeChecker.checkParents(module.moduleClass.asClass, parents)
         val cls = module.moduleClass
         val clsDef = ClassDef(cls, parents, body)
         val newCls = Apply(Select(New(TypeIdent(cls)), cls.primaryConstructor), Nil)

tests/neg-macros/i19842.check → tests/neg-macros/i19842-a.check

@@ -1,28 +1,18 @@
--- Error: tests/neg-macros/i19842/Test.scala:9:50 ----------------------------------------------------------------------
+-- Error: tests/neg-macros/i19842-a/Test.scala:9:50 --------------------------------------------------------------------
 9 |@main def Test = summon[Serializer[ValidationCls]] // error
   |                                                  ^
-  |Malformed tree was found while expanding macro with -Xcheck-macros.
-  |The tree does not conform to the compiler's tree invariants.
-  |
-  |Macro was:
-  |scala.quoted.runtime.Expr.splice[Serializer[ValidationCls]](((contextual$2: scala.quoted.Quotes) ?=> Macros.makeSerializer[ValidationCls](scala.quoted.Type.of[ValidationCls](contextual$2), contextual$2)))
-  |
-  |The macro returned:
-  |{
-  |  object objectSerializer$macro$1 extends Serializer[ValidationCls] { this: objectSerializer$macro$1.type =>
-  |    
-  |  }
-  |  objectSerializer$macro$1
-  |}
-  |
-  |Error:
-  |assertion failed: Parents of class symbol differs from the parents in the tree for object objectSerializer$macro$1
+  |Exception occurred while executing macro expansion.
+  |java.lang.AssertionError: assertion failed: Parents of class symbol differs from the parents in the tree for object objectSerializer$macro$1
   |
   |Parents in symbol: [class Object, trait Serializer]
   |Parents in tree: [trait Serializer]
   |
+  |	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
+  |	at dotty.tools.dotc.transform.TreeChecker$.checkParents(TreeChecker.scala:209)
+  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$ClassDef$.module(QuotesImpl.scala:257)
+  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$ClassDef$.module(QuotesImpl.scala:256)
+  |	at Macros$.makeSerializer(Macro.scala:25)
   |
-  |stacktrace available when compiling with `-Ydebug`
   |---------------------------------------------------------------------------------------------------------------------
   |Inline stack trace
   |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

tests/neg-macros/i19842/Macro.scala → tests/neg-macros/i19842-a/Macro.scala

@@ -16,7 +16,6 @@ object Macros {
       name,
       Flags.Implicit,
       Flags.EmptyFlags,
-      // Without TypeRep.of[Object] it would fail with java.lang.AssertionError: assertion failed: First parent must be a class
       List(TypeRepr.of[Object], TypeRepr.of[Serializer[T]]),
       _ => Nil,
       Symbol.noSymbol

tests/neg-macros/i19842-b.check

@@ -0,0 +1,22 @@
+-- Error: tests/neg-macros/i19842-b/Test.scala:9:50 --------------------------------------------------------------------
+9 |@main def Test = summon[Serializer[ValidationCls]] // error
+  |                                                  ^
+  |Exception occurred while executing macro expansion.
+  |java.lang.AssertionError: assertion failed: Parents of class symbol differs from the parents in the tree for object objectSerializer$macro$1
+  |
+  |Parents in symbol: [class Object, trait Serializer]
+  |Parents in tree: [class Object, trait Serializer, trait Foo]
+  |
+  |	at scala.runtime.Scala3RunTime$.assertFailed(Scala3RunTime.scala:8)
+  |	at dotty.tools.dotc.transform.TreeChecker$.checkParents(TreeChecker.scala:209)
+  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$ClassDef$.module(QuotesImpl.scala:257)
+  |	at scala.quoted.runtime.impl.QuotesImpl$reflect$ClassDef$.module(QuotesImpl.scala:256)
+  |	at Macros$.makeSerializer(Macro.scala:27)
+  |
+  |---------------------------------------------------------------------------------------------------------------------
+  |Inline stack trace
+  |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+  |This location contains code that was inlined from Test.scala:5
+5 |    implicit inline def implicitMakeSerializer[T]: Serializer[T] = ${ Macros.makeSerializer[T] }
+  |                                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   ---------------------------------------------------------------------------------------------------------------------

tests/neg-macros/i19842-b/Macro.scala

@@ -0,0 +1,31 @@
+//> using options -experimental -Yno-experimental
+
+import scala.annotation.{experimental, targetName}
+import scala.quoted.*
+import scala.util.Try
+
+trait Foo
+
+object Macros {
+  def makeSerializer[T: Type](using Quotes): Expr[Serializer[T]] = {
+    import quotes.reflect.*
+
+    val tpe: TypeRepr = TypeRepr.of[T]
+    val name: String = Symbol.freshName("objectSerializer")
+
+    val modSym: Symbol = Symbol.newModule(
+      Symbol.spliceOwner,
+      name,
+      Flags.Implicit,
+      Flags.EmptyFlags,
+      List(TypeRepr.of[Object], TypeRepr.of[Serializer[T]]),
+      _ => Nil,
+      Symbol.noSymbol
+    )
+
+    val (modValDef: ValDef, modClassDef: ClassDef) =
+      ClassDef.module(modSym, List(TypeTree.of[Object], TypeTree.of[Serializer[T]], TypeTree.of[Foo]), Nil)
+
+    Block(List(modValDef, modClassDef), Ref(modSym)).asExprOf[Serializer[T]]
+  }
+}

tests/neg-macros/i19842-b/Test.scala

@@ -0,0 +1,9 @@
+
+trait Serializer[@specialized T]
+
+object Serializer:
+    implicit inline def implicitMakeSerializer[T]: Serializer[T] = ${ Macros.makeSerializer[T] }
+
+case class ValidationCls(string: String)
+
+@main def Test = summon[Serializer[ValidationCls]] // error