Reland "[typedarray] Make JSTypedArray::length authoritative."

This is a reland of ad44c258d7c2df82b3252cd11cf2c329dc4ca86b

Patchset 2 is the original CL
Patchset 3 fixes some misuses of FixedArrayBase::length() and adds some
DCHECKS to flush out any more misuses.
Patchset 4 adds the PPC/S390 port by miladfar@ca.ibm.com.

Original change's description:
> [typedarray] Make JSTypedArray::length authoritative.
>
> This is the first step towards full huge typed array support in V8.
> Before this change, the JSTypedArray::length and the elements backing
> store length (FixedTypedArrayBase::length) were used more or less
> interchangeably to determine the number of elements in a JSTypedArray.
>
> With this change we disentangle these two lengths, and instead make
> JSTypedArray::length authoritative. For on-heap typed arrays, the
> FixedTypedArrayBase::length will remain the number of elements in the
> backing store, but for the off-heap typed arrays, this length will be
> set to 0 (matching the fact that the FixedTypedArrayBase instance does
> not contain any elements itself).
>
> This also unifies the JSTypedArray::set_/length() and length_value()
> methods to only have JSTypedArray::set_/length() which returns/takes
> size_t values. Currently this still requires the values to be in Smi
> range, but later we will extend this to allow arbitrary size_t values
> (in the safe integer range).
>
> Bug: v8:4153, v8:7881
> Change-Id: Iff9089130bb31fa9e08e0cf913e7ab52c3dbf107
> Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
> Doc: http://doc/1Z-wM2qwvAuxH46e9ivtkYvKzzwYZg8ymm0x0wJaomow
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1543729
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ben Titzer <titzer@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#60648}

Bug: v8:4153, v8:7881, v8:9105
Change-Id: Ic38f833071a723642ebc6f82a4012dbc0878ef98
Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1594435
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61275}
37 files changed
tree: 83781313785d011bf5ee7a57ee7739339e86effb
  1. benchmarks/
  2. build_overrides/
  3. custom_deps/
  4. docs/
  5. gni/
  6. include/
  7. infra/
  8. samples/
  9. src/
  10. test/
  11. testing/
  12. third_party/
  13. tools/
  14. .clang-format
  15. .clang-tidy
  16. .editorconfig
  17. .git-blame-ignore-revs
  18. .gitattributes
  19. .gitignore
  20. .gn
  21. .vpython
  22. .ycm_extra_conf.py
  23. AUTHORS
  24. BUILD.gn
  25. ChangeLog
  26. CODE_OF_CONDUCT.md
  27. codereview.settings
  28. DEPS
  29. LICENSE
  30. LICENSE.fdlibm
  31. LICENSE.strongtalk
  32. LICENSE.v8
  33. LICENSE.valgrind
  34. OWNERS
  35. PRESUBMIT.py
  36. README.md
  37. snapshot_toolchain.gni
  38. WATCHLISTS
README.md

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://v8.dev/docs

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*

Contributing

Please follow the instructions mentioned at v8.dev/docs/contribute.