Merge pull request #11601 from dotty-staging/fix-11538

Make generation of local contexts uniform

Author: nicolasstucki

compiler/src/dotty/tools/dotc/ast/TreeMapWithImplicits.scala

@@ -85,8 +85,6 @@ class TreeMapWithImplicits extends tpd.TreeMap {
   }
 
   override def transform(tree: Tree)(using Context): Tree = {
-    def localCtx =
-      if (tree.hasType && tree.symbol.exists) ctx.withOwner(tree.symbol) else ctx
     try tree match {
       case Block(stats, expr) =>
         inContext(nestedScopeCtx(stats)) {
@@ -97,19 +95,13 @@ class TreeMapWithImplicits extends tpd.TreeMap {
           else super.transform(tree)
         }
       case tree: DefDef =>
-        inContext(localCtx) {
+        inContext(localCtx(tree)) {
           cpy.DefDef(tree)(
             tree.name,
             transformParamss(tree.paramss),
             transform(tree.tpt),
             transform(tree.rhs)(using nestedScopeCtx(tree.paramss.flatten)))
         }
-      case EmptyValDef =>
-        tree
-      case _: MemberDef =>
-        super.transform(tree)(using localCtx)
-      case _: PackageDef =>
-        super.transform(tree)(using ctx.withOwner(tree.symbol.moduleClass))
       case impl @ Template(constr, parents, self, _) =>
         cpy.Template(tree)(
           transformSub(constr),

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -1296,6 +1296,9 @@ object Trees {
      */
     protected def inlineContext(call: Tree)(using Context): Context = ctx
 
+    /** The context to use when mapping or accumulating over a tree */
+    def localCtx(tree: Tree)(using Context): Context
+
     abstract class TreeMap(val cpy: TreeCopier = inst.cpy) { self =>
       def transform(tree: Tree)(using Context): Tree = {
         inContext(
@@ -1304,9 +1307,6 @@ object Trees {
           else ctx
         ){
           Stats.record(s"TreeMap.transform/$getClass")
-          def localCtx =
-            if (tree.hasType && tree.symbol.exists) ctx.withOwner(tree.symbol) else ctx
-
           if (skipTransform(tree)) tree
           else tree match {
             case Ident(name) =>
@@ -1362,11 +1362,11 @@ object Trees {
             case AppliedTypeTree(tpt, args) =>
               cpy.AppliedTypeTree(tree)(transform(tpt), transform(args))
             case LambdaTypeTree(tparams, body) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 cpy.LambdaTypeTree(tree)(transformSub(tparams), transform(body))
               }
             case TermLambdaTypeTree(params, body) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 cpy.TermLambdaTypeTree(tree)(transformSub(params), transform(body))
               }
             case MatchTypeTree(bound, selector, cases) =>
@@ -1384,17 +1384,17 @@ object Trees {
             case EmptyValDef =>
               tree
             case tree @ ValDef(name, tpt, _) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 val tpt1 = transform(tpt)
                 val rhs1 = transform(tree.rhs)
                 cpy.ValDef(tree)(name, tpt1, rhs1)
               }
             case tree @ DefDef(name, paramss, tpt, _) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 cpy.DefDef(tree)(name, transformParamss(paramss), transform(tpt), transform(tree.rhs))
               }
             case tree @ TypeDef(name, rhs) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 cpy.TypeDef(tree)(name, transform(rhs))
               }
             case tree @ Template(constr, parents, self, _) if tree.derived.isEmpty =>
@@ -1404,7 +1404,10 @@ object Trees {
             case Export(expr, selectors) =>
               cpy.Export(tree)(transform(expr), selectors)
             case PackageDef(pid, stats) =>
-              cpy.PackageDef(tree)(transformSub(pid), transformStats(stats, pid.symbol.moduleClass)(using localCtx))
+              val pid1 = transformSub(pid)
+              inContext(localCtx(tree)) {
+                cpy.PackageDef(tree)(pid1, transformStats(stats, ctx.owner))
+              }
             case Annotated(arg, annot) =>
               cpy.Annotated(tree)(transform(arg), transform(annot))
             case Thicket(trees) =>
@@ -1450,8 +1453,6 @@ object Trees {
           foldOver(x, tree)(using ctx.withSource(tree.source))
         else {
           Stats.record(s"TreeAccumulator.foldOver/$getClass")
-          def localCtx =
-            if (tree.hasType && tree.symbol.exists) ctx.withOwner(tree.symbol) else ctx
           tree match {
             case Ident(name) =>
               x
@@ -1506,11 +1507,11 @@ object Trees {
             case AppliedTypeTree(tpt, args) =>
               this(this(x, tpt), args)
             case LambdaTypeTree(tparams, body) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 this(this(x, tparams), body)
               }
             case TermLambdaTypeTree(params, body) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 this(this(x, params), body)
               }
             case MatchTypeTree(bound, selector, cases) =>
@@ -1526,15 +1527,15 @@ object Trees {
             case UnApply(fun, implicits, patterns) =>
               this(this(this(x, fun), implicits), patterns)
             case tree @ ValDef(_, tpt, _) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 this(this(x, tpt), tree.rhs)
               }
             case tree @ DefDef(_, paramss, tpt, _) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 this(this(paramss.foldLeft(x)(apply), tpt), tree.rhs)
               }
             case TypeDef(_, rhs) =>
-              inContext(localCtx) {
+              inContext(localCtx(tree)) {
                 this(x, rhs)
               }
             case tree @ Template(constr, parents, self, _) if tree.derived.isEmpty =>
@@ -1544,7 +1545,7 @@ object Trees {
             case Export(expr, _) =>
               this(x, expr)
             case PackageDef(pid, stats) =>
-              this(this(x, pid), stats)(using localCtx)
+              this(this(x, pid), stats)(using localCtx(tree))
             case Annotated(arg, annot) =>
               this(this(x, arg), annot)
             case Thicket(ts) =>

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -565,6 +565,14 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
       else foldOver(sym, tree)
   }
 
+  /** The owner to be used in a local context when traversin a tree */
+  def localOwner(tree: Tree)(using Context): Symbol =
+    val sym = tree.symbol
+    (if sym.is(PackageVal) then sym.moduleClass else sym).orElse(ctx.owner)
+
+  /** The local context to use when traversing trees */
+  def localCtx(tree: Tree)(using Context): Context = ctx.withOwner(localOwner(tree))
+
   override val cpy: TypedTreeCopier = // Type ascription needed to pick up any new members in TreeCopier (currently there are none)
     TypedTreeCopier()
 

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -535,6 +535,8 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
 
 // --------- Copier/Transformer/Accumulator classes for untyped trees -----
 
+  def localCtx(tree: Tree)(using Context): Context = ctx
+
   override val cpy: UntypedTreeCopier = UntypedTreeCopier()
 
   class UntypedTreeCopier extends TreeCopier {

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -542,7 +542,7 @@ object Contexts {
       def iinfo(using Context) =
         if (ctx.importInfo == null) "" else i"${ctx.importInfo.selectors}%, %"
       def cinfo(using Context) =
-        val core = s"  owner = ${ctx.owner}, scope = ${ctx.scope}, import = ${iinfo(using ctx)}"
+        val core = s"  owner = ${ctx.owner}, scope = ${ctx.scope}, import = $iinfo"
         if (ctx ne NoContext) && (ctx.implicits ne ctx.outer.implicits) then
           s"$core, implicits = ${ctx.implicits}"
         else

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

@@ -31,11 +31,8 @@ abstract class MacroTransform extends Phase {
 
   class Transformer extends TreeMap(cpy = cpyBetweenPhases) {
 
-    protected def localCtx(tree: Tree)(using Context): FreshContext = {
-      val sym = tree.symbol
-      val owner = if (sym.is(PackageVal)) sym.moduleClass else sym
-      ctx.fresh.setTree(tree).setOwner(owner)
-    }
+    protected def localCtx(tree: Tree)(using Context): FreshContext = 
+      ctx.fresh.setTree(tree).setOwner(localOwner(tree))
 
     override def transformStats(trees: List[Tree], exprOwner: Symbol)(using Context): List[Tree] = {
       def transformStat(stat: Tree): Tree = stat match {