• Daniel Clifford's avatar
    [torque] generate Cast<> macros from Torque-defined classes · 1052dfb3
    Daniel Clifford authored
    This change enables automatic generation of Cast<> operators for
    classes that are defined in Torque.
    
    * Cast<> macros are generated for all classes that are defined in
      Torque code that are neither shapes nor marked with a new
      @doNotGenerateCast annotation.
    
    * Implicitly generated Cast macros simply call through to an
      internally-defined "DownCastForTorqueClass" macro that implements
      the cast using one of three strategies for efficiency. If the class
      has subclasses (i.e. a range of instance types including subtypes),
      the DownCastForTorqueClass checks for inclusion in the instance type
      range. If the class has a single instance type (i.e. no subclasses),
      then either 1) a map check is used if the class has a globally-
      defined map constant or 2) an equality check for the instance type
      is used.
    
    * Added new intrinsics to introspect class information, e.g. fetching
      instance type ranges for a class, accessing the globally-defined map
      for a class.
    
    * Removed a whole pile of existing explicit Cast<> operators that are
      no longer needed because of the implicitly generated Cast<> macros.
    
    * Added tests for the new Cast<> implementations.
    
    Bug: v8:7793
    Change-Id: I3aadb0c62b720e9de4e7978b9ec4f05075771b8b
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2250239
    Commit-Queue: Daniel Clifford <danno@chromium.org>
    Reviewed-by: 's avatarTobias Tebbi <tebbi@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#68478}
    1052dfb3
constants.h 6.34 KB