Do not force trees when linking

Author: nicolasstucki

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

@@ -27,10 +27,11 @@ class CompilationUnit(val source: SourceFile) {
 object CompilationUnit {
 
   /** Make a compilation unit for top class `clsd` with the contends of the `unpickled` */
-  def mkCompilationUnit(clsd: ClassDenotation, unpickled: Tree)(implicit ctx: Context): CompilationUnit = {
+  def mkCompilationUnit(clsd: ClassDenotation, unpickled: Tree, forceTrees: Boolean)(implicit ctx: Context): CompilationUnit = {
     val unit1 = new CompilationUnit(new SourceFile(clsd.symbol.sourceFile, Seq()))
     unit1.tpdTree = unpickled
-    force.traverse(unit1.tpdTree)
+    if (forceTrees)
+      force.traverse(unit1.tpdTree)
     unit1
   }
 

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

@@ -81,7 +81,7 @@ object FromTasty extends Driver {
               case info: ClassfileLoader =>
                 info.load(clsd)
                 val unpickled = clsd.symbol.asClass.tree
-                if (unpickled != null) CompilationUnit.mkCompilationUnit(clsd, unpickled)
+                if (unpickled != null) CompilationUnit.mkCompilationUnit(clsd, unpickled, forceTrees = true)
                 else cannotUnpickle(s"its class file ${info.classfile} does not have a TASTY attribute")
               case info =>
                 cannotUnpickle(s"its info of type ${info.getClass} is not a ClassfileLoader")

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

@@ -71,7 +71,7 @@ object LinkAll {
     if (tree.isEmpty) None
     else {
       ctx.log("Loading compilation unit for: " + clsd)
-      Some(CompilationUnit.mkCompilationUnit(clsd, tree))
+      Some(CompilationUnit.mkCompilationUnit(clsd, tree, forceTrees = false))
     }
   }