• Michael Lippautz's avatar
    Revert "[heap, api] Check assumptions for embedder fields on set" · bcd0fa55
    Michael Lippautz authored
    This reverts commit 61193620.
    
    Reason for revert: Blocking roll: https://chromium-review.googlesource.com/c/chromium/src/+/3802992/
    
    Original change's description:
    > [heap, api] Check assumptions for embedder fields on set
    >
    > Previously, we would set embedder fields and do type checks (on
    > embedder fields) in the GC. This does not work nicely as embedder
    > fields contain system pointers whereas we can only operate with
    > tag-aligned reads/writes. The end result of assembling pointers was
    > somtimes broken for concurrent marking.
    >
    > In this CL we reverse the mode and check assumptions when writing the
    > fields. From Blink we generally only write once and use the fields in
    > the GC and via reads multiple times.
    >
    > We assume, that when running with CppHeap, any pointer on an instance
    > field that points into CppHeap, also has the type field set with the
    > appropriate tracing information. In debug builds we also verify that
    > the embedder field indeed points to the start of an Oilpan object.
    >
    > Bug: chromium:1337690
    > Change-Id: I9f9a8e691cdcf666861a455dcf8f65f2fe80b034
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3788206
    > Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
    > Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
    > Reviewed-by: Omer Katz <omerkatz@chromium.org>
    > Reviewed-by: Igor Sheludko <ishell@chromium.org>
    > Cr-Commit-Position: refs/heads/main@{#82120}
    
    Bug: chromium:1337690
    Change-Id: Iaece8f51883c7d001fb18ef48faaf271c48b8f11
    No-Presubmit: true
    No-Tree-Checks: true
    No-Try: true
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3804245
    Commit-Queue: Leszek Swirski <leszeks@chromium.org>
    Owners-Override: Leszek Swirski <leszeks@chromium.org>
    Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
    Cr-Commit-Position: refs/heads/main@{#82127}
    bcd0fa55