Enter missing symbols in MacroAnnotations

Author: hamzaremmal

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -7,7 +7,6 @@ import typer.{TyperPhase, RefChecks}
 import parsing.Parser
 import Phases.Phase
 import transform._
-import dotty.tools.backend
 import backend.jvm.{CollectSuperCalls, GenBCode}
 import localopt.StringInterpolatorOpt
 

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

@@ -17,7 +17,8 @@ import dotty.tools.dotc.staging.StagingLevel
 import scala.collection.mutable.ListBuffer
 
 /** Inlines all calls to inline methods that are not in an inline method or a quote */
-class Inlining extends MacroTransform {
+class Inlining extends MacroTransform, IdentityDenotTransformer {
+  self =>
 
   import tpd._
 
@@ -75,7 +76,7 @@ class Inlining extends MacroTransform {
             && StagingLevel.level == 0
             && MacroAnnotations.hasMacroAnnotation(tree.symbol)
           then
-            val trees = (new MacroAnnotations).expandAnnotations(tree)
+            val trees = (new MacroAnnotations(self)).expandAnnotations(tree)
             val trees1 = trees.map(super.transform)
 
             // Find classes added to the top level from a package object

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

@@ -9,7 +9,7 @@ import dotty.tools.dotc.config.Printers.{macroAnnot => debug}
 import dotty.tools.dotc.core.Annotations.*
 import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.core.Decorators.*
-import dotty.tools.dotc.core.DenotTransformers.DenotTransformer
+import dotty.tools.dotc.core.DenotTransformers.IdentityDenotTransformer
 import dotty.tools.dotc.core.Flags.*
 import dotty.tools.dotc.core.MacroClassLoader
 import dotty.tools.dotc.core.Symbols.*
@@ -23,7 +23,8 @@ import scala.util.control.NonFatal
 
 import java.lang.reflect.InvocationTargetException
 
-class MacroAnnotations:
+class MacroAnnotations(phase: IdentityDenotTransformer):
+
   import tpd.*
   import MacroAnnotations.*
 
@@ -58,9 +59,14 @@ class MacroAnnotations:
             case (prefixed, newTree :: suffixed) =>
               allTrees ++= prefixed
               insertedAfter = suffixed :: insertedAfter
-              prefixed.foreach(checkMacroDef(_, tree, annot))
-              suffixed.foreach(checkMacroDef(_, tree, annot))
-              transform.TreeChecker.checkMacroGeneratedTree(tree, newTree)
+              for prefixedTree <- prefixed do
+                checkMacroDef(prefixedTree, tree, annot)
+                enterMissingSymbols(prefixedTree)
+              for suffixedTree <- suffixed do
+                checkMacroDef(suffixedTree, tree, annot)
+                enterMissingSymbols(suffixedTree)
+              TreeChecker.checkMacroGeneratedTree(tree, newTree)
+              enterMissingSymbols(newTree)
               newTree
             case (Nil, Nil) =>
               report.error(i"Unexpected `Nil` returned by `(${annot.tree}).transform(..)` during macro expansion", annot.tree.srcPos)
@@ -120,7 +126,7 @@ class MacroAnnotations:
 
   /** Check that this tree can be added by the macro annotation */
   private def checkMacroDef(newTree: DefTree, annotatedTree: Tree, annot: Annotation)(using Context) =
-    transform.TreeChecker.checkMacroGeneratedTree(annotatedTree, newTree)
+    TreeChecker.checkMacroGeneratedTree(annotatedTree, newTree)
     val sym = newTree.symbol
     val annotated = annotatedTree.symbol
     if sym.isType && !sym.isClass then
@@ -130,6 +136,20 @@ class MacroAnnotations:
     else if annotated.isClass && annotated.owner.is(Package) /*&& !sym.isClass*/ then
       report.error(i"macro annotation can not add top-level ${sym.showKind}. $annot tried to add $sym.", annot.tree)
 
+  private def enterMissingSymbols(tree: MemberDef)(using Context) = new TreeTraverser {
+    def traverse(tree: tpd.Tree)(using Context): Unit = tree match
+      case tdef @ TypeDef(_, template: Template) =>
+        //for tree <- template.constr :: template.body do
+        val isSymbolInDecls = tdef.symbol.asClass.info.decls.toList.toSet
+        for tree <- template.body do
+          if tree.symbol.owner != tdef.symbol then
+            report.error(em"Macro added a definition with the wrong owner - ${tree.symbol.owner} - ${tdef.symbol} in ${tree.source}")
+          else if !isSymbolInDecls(tree.symbol) then
+            tree.symbol.enteredAfter(phase)
+        traverseChildren(tree) // Taverse before or after dealing with this class?
+      case _ => traverseChildren(tree)
+  }.traverse(tree)
+
 object MacroAnnotations:
 
   /** Is this an annotation that implements `scala.annation.MacroAnnotation` */

tests/neg-macros/i18825.check

@@ -0,0 +1,3 @@
+
+error overriding method toString in class Foo of type (): String;
+  method toString of type (): String cannot override final member method toString in class Foo

tests/neg-macros/i18825/Macro_1.scala

@@ -0,0 +1,19 @@
+import scala.annotation.experimental
+import scala.annotation.MacroAnnotation
+import scala.quoted.*
+
+@experimental
+class toString extends MacroAnnotation :
+  def transform(using Quotes)(tree: quotes.reflect.Definition): List[quotes.reflect.Definition] =
+    import quotes.reflect.*
+    tree match
+      case ClassDef(name, ctr, parents, self, body) =>
+        val cls = tree.symbol
+        val toStringSym = Symbol.requiredMethod("java.lang.Object.toString")
+        val toStringOverrideSym = Symbol.newMethod(cls, "toString", toStringSym.info, Flags.Override, Symbol.noSymbol)
+        val toStringDef = DefDef(toStringOverrideSym, _ => Some(Literal(StringConstant("Hello from macro"))))
+        val newClassDef = ClassDef.copy(tree)(name, ctr, parents, self, toStringDef :: body)
+        List(newClassDef)
+      case _ =>
+        report.error("@toString can only be annotated on class definitions")
+        tree :: Nil

tests/neg-macros/i18825/Test_2.scala

@@ -0,0 +1,15 @@
+// nopos-error
+
+import annotation.experimental
+
+class Foo :
+  final override def toString(): String = "Hello"
+
+@experimental
+@toString
+class AFoo extends Foo //:
+  //override def toString(): String = "Hello from macro"
+
+@experimental
+@main def run =
+  println(new AFoo().toString)