path: root/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala

package scala.tools.nsc
package typechecker

trait StdAttachments {
  self: Analyzer =>

  import global._

  /** Carries information necessary to expand the host tree.
   *  At times we need to store this info, because macro expansion can be delayed until its targs are inferred.
   *  After a macro application has been successfully expanded, this attachment is destroyed.
   */
  type UnaffiliatedMacroContext = scala.reflect.macros.runtime.Context
  type MacroContext = UnaffiliatedMacroContext { val universe: self.global.type }
  case class MacroRuntimeAttachment(delayed: Boolean, typerContext: Context, macroContext: Option[MacroContext])

  /** After being synthesized by the parser, primary constructors aren't fully baked yet.
   *  A call to super in such constructors is just a fill-me-in-later dummy resolved later
   *  by `parentTypes`. This attachment coordinates `parentTypes` and `typedTemplate` and
   *  allows them to complete the synthesis.
   */
  case class SuperCallArgsAttachment(argss: List[List[Tree]])

  /** Extractor for `SuperCallArgsAttachment`.
   *  Compared with `MacroRuntimeAttachment` this attachment has different a usage pattern,
   *  so it really benefits from a dedicated extractor.
   */
  object CarriesSuperCallArgs {
    def unapply(tree: Tree): Option[List[List[Tree]]] =
      tree.attachments.get[SuperCallArgsAttachment] collect { case SuperCallArgsAttachment(argss) => argss }
  }
}