AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity
67,326 Commits 1 Branch 0 Tags 839 MiB
C++ 67.6%
JavaScript 30.1%
Python 1.2%
C 0.3%
TypeScript 0.3%
Other 0.4%
76a2ab06a1
Go to file
Jakob Gruber 76a2ab06a1 [compiler] Direct heap reads for JSArrayRef 
There are two aspects to the non-JSObject parts of JSArrayRef:

- JSArrayRef::length. Relevant only in two spots, 1. when reading
(immutable) array boilerplates and 2. for GetOwnCowElement.

- JSArrayRef::GetOwnCowElement. May read into a copy-on-write backing
store. Relies on the invariant that cow backing stores are immutable.

This CL renames the length accessor to length_unsafe to make the
danger explicit at callsites.

For GetOwnCowElement the refactor is slightly larger, since we now
need to read into the backing store while keeping full control of
object reads (e.g. JSArray::length and JSArray::elements_kind). We
make all reads explicit at the call site by requiring that elements,
elements kind, and length are passed in as arguments to
GetOwnCowElement. Inside GetOwnCowElement, consistency between these
is *not* guaranteed due to concurrency. At runtime, consistency *is*
guaranteed through the reference-equality check on the elements seen
during compilation. The actual elements read is implemented in
ConcurrentLookupIterator::GetOwnCowElement.

Bug: v8:7790
Change-Id: I9aa169ce4f2b1e2bfe1e9232007669eb7654a995
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2695403
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72834}
2021-02-18 08:08:08 +00:00
.github [github] Close PRs created on the V8 GitHub mirror automatically 2021-01-12 08:39:59 +00:00
build_overrides [build] Remove obsolete gn flag 2021-01-11 15:50:59 +00:00
custom_deps Use relative paths to OWNERS files 2019-08-12 13:52:52 +00:00
docs Add OWNERS for docs/ 2019-05-15 12:06:15 +00:00
gni Add RISC-V backend 2021-02-09 17:06:36 +00:00
include cppgc: Implement process-global state accessors. 2021-02-17 22:37:24 +00:00
infra Add bot to compile with v8_enable_webassembly=false 2021-02-17 15:38:15 +00:00
samples cppgc: Avoid initializing cppgc platform through V8 2021-02-09 08:26:11 +00:00
src [compiler] Direct heap reads for JSArrayRef 2021-02-18 08:08:08 +00:00
test [compiler] Direct heap reads for JSArrayRef 2021-02-18 08:08:08 +00:00
testing build: Remove no-op calls to set_sources_assignment_filter 2020-10-08 14:44:01 +00:00
third_party Remove tebbi from OWNERS and TODOs 2021-01-21 13:23:00 +00:00
tools Remove 'length' field from ScopeInfo 2021-02-17 21:23:59 +00:00
.clang-format [clang-format] Don't derive pointer alignment 2017-01-17 09:28:19 +00:00
.clang-tidy [tool] Remove unfixed clang-tidy warnings to ease use. 2018-10-26 07:40:32 +00:00
.editorconfig Add .editorconfig 2017-07-28 13:39:24 +00:00
.flake8 Add .flake8 to allow for python style checking. 2019-07-19 21:44:03 +00:00
.git-blame-ignore-revs [infra] Update .git-blame-ignore-revs 2020-03-03 12:59:13 +00:00
.gitattributes .gitattributes: Mark minified emscripten js files as -diff 2018-09-19 16:27:10 +00:00
.gitignore [build] Remove legacy binutils 2021-01-08 12:33:31 +00:00
.gn [build] Dynamically decide if to use system xcode 2019-07-29 08:20:24 +00:00
.vpython [tools] Implement confidence-based number of runs 2019-05-09 09:42:28 +00:00
.ycm_extra_conf.py Fix ycm config for headers without source 2019-12-09 11:59:21 +00:00
AUTHORS Add RISC-V backend 2021-02-09 17:06:36 +00:00
BUILD.gn cppgc: Implement process-global state accessors. 2021-02-17 22:37:24 +00:00
CODE_OF_CONDUCT.md Explicitly state that the Chromium Code of Conduct also applies to V8 2016-03-02 09:51:24 +00:00
codereview.settings Make Gerrit the default code review for V8 2017-06-30 17:37:37 +00:00
COMMON_OWNERS Remove tebbi from OWNERS and TODOs 2021-01-21 13:23:00 +00:00
DEPS Update V8 DEPS. 2021-02-18 04:01:18 +00:00
DIR_METADATA Add DIR_METADATA files to v8. 2020-10-20 22:12:28 +00:00
ENG_REVIEW_OWNERS Add eng review owners as escalation path 2019-05-15 19:12:10 +00:00
INFRA_OWNERS Add team members as owners 2020-08-18 08:29:04 +00:00
INTL_OWNERS add ftang as owner 2020-04-24 19:19:36 +00:00
LICENSE [wasm] Draft version of C/C++ Wasm API 2019-04-17 16:00:26 +00:00
LICENSE.fdlibm Add LICENSE.fdlibm for all the fdlibm imported sources. 2016-06-09 07:17:03 +00:00
LICENSE.strongtalk Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
LICENSE.v8 Add LICENSE.v8, LICENSE.strongtalk and LICENSE.valgrind to the v8 2011-02-03 07:10:06 +00:00
MIPS_OWNERS [mips] Request to be an owner of MIPS files 2020-11-23 09:43:49 +00:00
OWNERS Add RISC-V backend 2021-02-09 17:06:36 +00:00
PPC_OWNERS Adding myself to relevant OWNERS files. 2020-11-02 16:37:28 +00:00
PRESUBMIT.py cppgc: Add testing API structure 2021-02-03 16:00:37 +00:00
README.md [docs] Change links from old wiki to v8.dev 2019-03-07 12:13:30 +00:00
RISCV_OWNERS Add RISC-V backend 2021-02-09 17:06:36 +00:00
S390_OWNERS Adding myself to relevant OWNERS files. 2020-11-02 16:37:28 +00:00
WATCHLISTS Add a watchlist for ieee754.(cc|h) changes. 2021-01-11 18:10:19 +00:00

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.