• Nicolò Ribaudo's avatar
    [class] Improve errors for reinitialized private elements · b3b9466a
    Nicolò Ribaudo authored
    Previously V8 was reusing the error fur duplicate declarations, using
    the private name for class fields or the class name for class methods
    as the redeclared identifier.
    
        class A { constructor(o) { return o } }
        class B extends A { #x }
        class C extends A { #x() {} }
        let D = (0, class extends A { #x() {} });
    
        new B(new B({})) // Identifier '#x' has already been declared
        new C(new C({})) // Identifier 'C' has already been declared
        new D(new D({})) // Identifier '' has already been declared
    
    This patch changes it to use error messages that better explain what's
    happening:
    
        new B(new B({})) // Cannot initialize #x twice on the same object
        new C(new C({})) // Cannot initialize private methods of
                         // class C twice on the same object
        new D(new D({})) // Cannot initialize private methods of
                         // class anonymous twice on the same object
    
    I initially tried to use the same message for both fields and methods,
    but the problem with that is that when initializing fields we only
    have access to the field name, while when initializing methods we only
    have access to the class name (using the "private brand" symbol).
    However, almost all the error messages are different for private fields
    and for methods so this shouldn't be a problem.
    
    Bug: v8:12042
    Change-Id: Iaa50c16e4fa5c0646ad9ef2aa7e65bb649b3fce2
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3078362Reviewed-by: 's avatarLeszek Swirski <leszeks@chromium.org>
    Reviewed-by: 's avatarJoyee Cheung <joyee@igalia.com>
    Commit-Queue: Leszek Swirski <leszeks@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#76279}
    b3b9466a
class-private-brand-reinitialization-anonymous.js 282 Bytes