Use transformStats top handle imports

Everything else is a deviation from, type checking and the spec.

Author: odersky

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

@@ -26,7 +26,7 @@ class TreeMapWithImplicits extends tpd.TreeMap {
    *   - be tail-recursive where possible
    *   - don't re-allocate trees where nothing has changed
    */
-  def transformStats(stats: List[Tree], exprOwner: Symbol)(using Context): List[Tree] = {
+  override def transformStats(stats: List[Tree], exprOwner: Symbol)(using Context): List[Tree] = {
 
     @tailrec def traverse(curStats: List[Tree])(using Context): List[Tree] = {
 
@@ -88,8 +88,14 @@ class TreeMapWithImplicits extends tpd.TreeMap {
     def localCtx =
       if (tree.hasType && tree.symbol.exists) ctx.withOwner(tree.symbol) else ctx
     try tree match {
-      case tree: Block =>
-        super.transform(tree)(using nestedScopeCtx(tree.stats))
+      case Block(stats, expr) =>
+        inContext(nestedScopeCtx(stats)) {
+          if stats.exists(_.isInstanceOf[Import]) then
+            // need to transform stats and expr together to account for import visibility
+            val stats1 = transformStats(stats :+ expr, ctx.owner)
+            cpy.Block(tree)(stats1.init, stats1.last)
+          else super.transform(tree)
+        }
       case tree: DefDef =>
         inContext(localCtx) {
           cpy.DefDef(tree)(

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

@@ -130,7 +130,7 @@ class TreeTypeMap(
       }
   }
 
-  override def transformStats(trees: List[tpd.Tree])(using Context): List[Tree] =
+  override def transformStats(trees: List[tpd.Tree], exprOwner: Symbol)(using Context): List[Tree] =
     transformDefs(trees)._2
 
   def transformDefs[TT <: tpd.Tree](trees: List[TT])(using Context): (TreeTypeMap, List[TT]) = {

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

@@ -1332,7 +1332,7 @@ object Trees {
             case Assign(lhs, rhs) =>
               cpy.Assign(tree)(transform(lhs), transform(rhs))
             case Block(stats, expr) =>
-              cpy.Block(tree)(transformStats(stats), transform(expr))
+              cpy.Block(tree)(transformStats(stats, ctx.owner), transform(expr))
             case If(cond, thenp, elsep) =>
               cpy.If(tree)(transform(cond), transform(thenp), transform(elsep))
             case Closure(env, meth, tpt) =>
@@ -1398,13 +1398,13 @@ object Trees {
                 cpy.TypeDef(tree)(name, transform(rhs))
               }
             case tree @ Template(constr, parents, self, _) if tree.derived.isEmpty =>
-              cpy.Template(tree)(transformSub(constr), transform(tree.parents), Nil, transformSub(self), transformStats(tree.body))
+              cpy.Template(tree)(transformSub(constr), transform(tree.parents), Nil, transformSub(self), transformStats(tree.body, tree.symbol))
             case Import(expr, selectors) =>
               cpy.Import(tree)(transform(expr), selectors)
             case Export(expr, selectors) =>
               cpy.Export(tree)(transform(expr), selectors)
             case PackageDef(pid, stats) =>
-              cpy.PackageDef(tree)(transformSub(pid), transformStats(stats)(using localCtx))
+              cpy.PackageDef(tree)(transformSub(pid), transformStats(stats, pid.symbol.moduleClass)(using localCtx))
             case Annotated(arg, annot) =>
               cpy.Annotated(tree)(transform(arg), transform(annot))
             case Thicket(trees) =>
@@ -1416,7 +1416,7 @@ object Trees {
         }
       }
 
-      def transformStats(trees: List[Tree])(using Context): List[Tree] =
+      def transformStats(trees: List[Tree], exprOwner: Symbol)(using Context): List[Tree] =
         transform(trees)
       def transform(trees: List[Tree])(using Context): List[Tree] =
         flatten(trees mapConserve (transform(_)))

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

@@ -659,7 +659,8 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
       case ModuleDef(name, impl) =>
         cpy.ModuleDef(tree)(name, transformSub(impl))
       case tree: DerivingTemplate =>
-        cpy.Template(tree)(transformSub(tree.constr), transform(tree.parents), transform(tree.derived), transformSub(tree.self), transformStats(tree.body))
+        cpy.Template(tree)(transformSub(tree.constr), transform(tree.parents),
+          transform(tree.derived), transformSub(tree.self), transformStats(tree.body, tree.symbol))
       case ParsedTry(expr, handler, finalizer) =>
         cpy.ParsedTry(tree)(transform(expr), transform(handler), transform(finalizer))
       case SymbolLit(str) =>

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

@@ -37,7 +37,7 @@ abstract class MacroTransform extends Phase {
       ctx.fresh.setTree(tree).setOwner(owner)
     }
 
-    def transformStats(trees: List[Tree], exprOwner: Symbol)(using Context): List[Tree] = {
+    override def transformStats(trees: List[Tree], exprOwner: Symbol)(using Context): List[Tree] = {
       def transformStat(stat: Tree): Tree = stat match {
         case _: Import | _: DefTree => transform(stat)
         case _ => transform(stat)(using ctx.exprContext(stat, exprOwner))

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

@@ -46,7 +46,7 @@ abstract class TreeMapWithStages(@constructorOnly ictx: Context) extends TreeMap
   /** The quotation level of the definition of the locally defined symbol */
   protected def levelOf(sym: Symbol): Int = levelOfMap.getOrElse(sym, 0)
 
-  /** Localy defined symbols seen so far by `StagingTransformer.transform` */
+  /** Locally defined symbols seen so far by `StagingTransformer.transform` */
   protected def localSymbols: List[Symbol] = enteredSyms
 
   /** If we are inside a quote or a splice */
@@ -74,7 +74,7 @@ abstract class TreeMapWithStages(@constructorOnly ictx: Context) extends TreeMap
   /** Transform the expression splice `splice` which contains the spliced `body`. */
   protected def transformSplice(body: Tree, splice: Apply)(using Context): Tree
 
-  /** Transform the typee splice `splice` which contains the spliced `body`. */
+  /** Transform the type splice `splice` which contains the spliced `body`. */
   protected def transformSpliceType(body: Tree, splice: Select)(using Context): Tree
 
   override def transform(tree: Tree)(using Context): Tree =
@@ -109,7 +109,7 @@ abstract class TreeMapWithStages(@constructorOnly ictx: Context) extends TreeMap
           try dropEmptyBlocks(quotedTree) match {
             case Spliced(t) =>
               // '{ $x } --> x
-              // and adapt the refinment of `Quotes { type tasty: ... } ?=> Expr[T]`
+              // and adapt the refinement of `Quotes { type reflect: ... } ?=> Expr[T]`
               transform(t).asInstance(tree.tpe)
             case _ => transformQuotation(quotedTree, tree)
           }

tests/pos/i11538a.scala

@@ -0,0 +1,23 @@
+package a:
+
+  trait Printer[A]:
+    def print(a: A): Unit
+
+  given Printer[String] with
+    def print(s: String) = println(s)
+
+package b:
+
+  import a.{given, *}
+
+  object test:
+    import scala.compiletime.{error, summonFrom}
+
+    inline def summonStringPrinter =
+      summonFrom {
+        case given Printer[String] => ()
+        case _ => error("Couldn't find a printer")
+      }
+
+    val summoned = summon[Printer[String]]
+    val summonedFrom = summonStringPrinter

tests/pos/i11538b.scala

@@ -0,0 +1,9 @@
+package a:
+  type Foo
+  given foo: Foo = ???
+
+import a.{Foo, given}
+object test:
+  inline def summonInlineFoo = scala.compiletime.summonInline[Foo]
+  val summoned = summon[Foo]
+  val summonedInline = summonInlineFoo

tests/pos/i11557.scala

@@ -0,0 +1,12 @@
+type MyEncoder
+
+class MyContext:
+  given intEncoder: MyEncoder = ???
+
+def doEncoding(ctx: MyContext): Unit =
+  import ctx.{*, given}
+  summon[MyEncoder]
+  summonInlineMyEncoder()
+
+inline def summonInlineMyEncoder(): Unit =
+  compiletime.summonInline[MyEncoder]