17f598782d
For string wrappers (JSValue instances with [[StringData]] internal
fields), we can shortcirciut the ToPrimitive if
(a) the {input} map matches the initial map of the String function,
(b) the {input} [[Prototype]] is the unmodified %StringPrototype% (i.e.
no one monkey-patched toString, @@toPrimitive or valueOf), and
(c) the %ObjectPrototype% (i.e. the [[Prototype]] of the
%StringPrototype%) is also unmodified, that is no one sneaked a
@@toPrimitive into the %ObjectPrototype%.
If all these assumptions hold, we can just take the [[StringData]] value
and return it.
This just repairs a regression introduced by removing the
weird (and broken) intrinsic %_IsStringWrapperSafeForDefaultValue, which
was intendend to something similar to this, although less efficient and
wrong in the presence of @@toPrimitive. Long-term we might want to move
into the direction of having a ToPrimitiveStub that can do common cases
while staying in JavaScript land (i.e. not going to C++).
R=jarin@chromium.org
BUG=chromium:532524
LOG=n
Review URL: https://codereview.chromium.org/1366563002
Cr-Commit-Position: refs/heads/master@{#30890}
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| benchmarks | ||
| build | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party/binutils | ||
| tools | ||
| .clang-format | ||
| .gitignore | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| ChangeLog | ||
| codereview.settings | ||
| DEPS | ||
| LICENSE | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| LICENSE.valgrind | ||
| Makefile | ||
| Makefile.android | ||
| Makefile.nacl | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.md | ||
| snapshot_toolchain.gni | ||
| WATCHLISTS | ||
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://code.google.com/p/v8/
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 on the V8 wiki.