• Tobias Tebbi's avatar
    [torque] add const references and disallow const class field writes · d7e02ea4
    Tobias Tebbi authored
    - Allow type expression for abstract type supertypes.
      For consistency, and ease of implementation, also allow this for enums.
    - Allow subtyping of structs. This requires changing all places where we
      checked for struct types and instead check if we have a subtype of a
      struct type.
    - This allows defining two subtypes of the Reference<T> struct for
      mutable and constant references. Mutable references are a subtype of
      constant references.
    - &T desugars to MutableReference<T>
      const &T desugars to ConstReference<T>
    - A const field of a class produces a constant reference.
      A const field of a mutable reference to a struct is const.
      A mutable field of a const reference to a struct is const.
    - It is possible to assign a new struct value to a mutable reference to
      a struct, even if the struct contains const fields. This is analogous
      to allowing assignments of let-bound structs with constant fields.
    
    Not in this CL:
    - A notion of const slices.
    - Applying const to appropriate class fields.
    
    Bug: v8:7793
    Change-Id: I6e7b09d44f54db25f8bf812be5f3b554b80414e0
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2096615Reviewed-by: 's avatarNico Hartmann <nicohartmann@chromium.org>
    Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#66759}
    d7e02ea4
declaration-visitor.cc 14.8 KB