We now have data that 0.011% of websites use the pattern
for (var i = 0 in j) { ... }
This pattern was banned by ES2015, with the idea to revisit if
it presents a web compatibility problem. Informally, after
the May 2016 TC39 meeting, the new data was discussed, and there
was interest in reversing the decision. Although the specification
is not yet updated, it seems likely to come soon.
This patch turns off the flag which bans that construct, reenabling
it. The change should prevent websites from breaking.
BUG=v8:4942
Review-Url: https://codereview.chromium.org/2011223003
Cr-Commit-Position: refs/heads/master@{#36562}
It was never being set to false in production (though it was in test-parsing.cc,
due to that test having its own flag-setting logic).
Review URL: https://codereview.chromium.org/1815033002
Cr-Commit-Position: refs/heads/master@{#34878}
Function declarations were previously permitted by V8 in many locations
which no ECMAScript specification allowed; the ECMAScript 2015 spec
enumerates a few locations (in blocks, as well as after labels and in
conditionals when in sloppy mode). This patch ships the flag to restrict
the usage of function declarations to those contexts.
R=adamk
LOG=Y
BUG=v8:4824
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1799233003
Cr-Commit-Position: refs/heads/master@{#34828}
This patch moves the semantics of 'const' in sloppy mode to match those
in strict mode, that is, const makes lexical (let-like) bindings, must
have an initializer, and does not create properties of the global object.
R=adamk
LOG=Y
BUG=v8:3305
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1571873004
Cr-Commit-Position: refs/heads/master@{#33218}
Reason for revert:
Crash fixed by https://codereview.chromium.org/1564923007
Original issue's description:
> Revert of Ship ES2015 sloppy-mode function hoisting, let, class (patchset #7 id:120001 of https://codereview.chromium.org/1551443002/ )
>
> Reason for revert:
> Causes frequent crashes in Canary: chromium:537816
>
> Original issue's description:
> > Ship ES2015 sloppy-mode function hoisting, let, class
> >
> > This patch doesn't ship all features of ES2015 variable/scoping
> > changes, notably omitting the removal of legacy const. I think
> > function hoisting, let and class in sloppy mode can stand to
> > themselves as a package, and the legacy const change is much
> > riskier and more likely to be reverted, so my intention is to
> > pursue those as a separate, follow-on patch.
> >
> > R=adamk@chromium.org
> > BUG=v8:4285,v8:3305
> > LOG=Y
> > CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
> >
> > Committed: https://crrev.com/fcff8588a5a01587643d6c2507c7b882c78a2957
> > Cr-Commit-Position: refs/heads/master@{#33133}
>
> TBR=adamk@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=v8:4285,v8:3305,chromium:537816
> LOG=Y
>
> Committed: https://crrev.com/adac5956c6216056a211cfaa460a00ac1500d8f8
> Cr-Commit-Position: refs/heads/master@{#33162}
TBR=adamk@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4285,v8:3305,chromium:537816
Review URL: https://codereview.chromium.org/1571793002
Cr-Commit-Position: refs/heads/master@{#33189}
Reason for revert:
Causes frequent crashes in Canary: chromium:537816
Original issue's description:
> Ship ES2015 sloppy-mode function hoisting, let, class
>
> This patch doesn't ship all features of ES2015 variable/scoping
> changes, notably omitting the removal of legacy const. I think
> function hoisting, let and class in sloppy mode can stand to
> themselves as a package, and the legacy const change is much
> riskier and more likely to be reverted, so my intention is to
> pursue those as a separate, follow-on patch.
>
> R=adamk@chromium.org
> BUG=v8:4285,v8:3305
> LOG=Y
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/fcff8588a5a01587643d6c2507c7b882c78a2957
> Cr-Commit-Position: refs/heads/master@{#33133}
TBR=adamk@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:4285,v8:3305,chromium:537816
LOG=Y
Review URL: https://codereview.chromium.org/1565263002
Cr-Commit-Position: refs/heads/master@{#33162}
This patch doesn't ship all features of ES2015 variable/scoping
changes, notably omitting the removal of legacy const. I think
function hoisting, let and class in sloppy mode can stand to
themselves as a package, and the legacy const change is much
riskier and more likely to be reverted, so my intention is to
pursue those as a separate, follow-on patch.
R=adamk@chromium.org
BUG=v8:4285,v8:3305
LOG=Y
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1551443002
Cr-Commit-Position: refs/heads/master@{#33133}
Unexpectedly, websites depend on doing feature testing with
RegExp.prototype.sticky and browser testing with RegExp.prototype.toString().
ES2015 newly throws exceptions for both of these. In order to enable shipping
new ES2015 semantics, this patch puts in narrow workarounds for those two
cases, keeping their old behavior. UseCounters are added for how often
those particular cases come up, so we can see if it can be deprecated.
This reland replaces problematic legacy const usage with var, to
avoid issues with nosnap builds.
R=yangguo
CC=bmeurer
BUG=v8:4637,v8:4617
LOG=Y
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1545633002
Cr-Commit-Position: refs/heads/master@{#33002}
Reason for revert:
Breaks nosnap: http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap/builds/5883
Original issue's description:
> Add web compat workarounds for ES2015 RegExp semantics
>
> Unexpectedly, websites depend on doing feature testing with
> RegExp.prototype.sticky and browser testing with RegExp.prototype.toString().
> ES2015 newly throws exceptions for both of these. In order to enable shipping
> new ES2015 semantics, this patch puts in narrow workarounds for those two
> cases, keeping their old behavior. UseCounters are added for how often
> those particular cases come up, so we can see if it can be deprecated.
>
> R=yangguo
> BUG=v8:4637,v8:4617
> LOG=Y
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/98f819c3e0c92d54a306cdacadda73cf96d21b52
> Cr-Commit-Position: refs/heads/master@{#32997}
TBR=yangguo@google.com,yangguo@chromium.org,littledan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4637,v8:4617
Review URL: https://codereview.chromium.org/1546493003
Cr-Commit-Position: refs/heads/master@{#32999}
Unexpectedly, websites depend on doing feature testing with
RegExp.prototype.sticky and browser testing with RegExp.prototype.toString().
ES2015 newly throws exceptions for both of these. In order to enable shipping
new ES2015 semantics, this patch puts in narrow workarounds for those two
cases, keeping their old behavior. UseCounters are added for how often
those particular cases come up, so we can see if it can be deprecated.
R=yangguo
BUG=v8:4637,v8:4617
LOG=Y
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1543723002
Cr-Commit-Position: refs/heads/master@{#32997}
Introduce a new Apply builtin that forms a correct and optimizable
foundation for the Function.prototype.apply, Reflect.construct and
Reflect.apply builtins (which properly does the PrepareForTailCall
as required by the ES2015 spec).
The new Apply builtin avoids going to the runtime if it is safe to
just access the backing store elements of the argArray, i.e. if you
pass a JSArray with no holes, or an unmapped, unmodified sloppy or
strict arguments object.
mips/mips64 ports by Balazs Kilvady <balazs.kilvady@imgtec.com>
CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux64_tsan_rel
BUG=v8:4413, v8:4430
LOG=n
R=yangguo@chromium.org
Committed: e4d2538911
Review URL: https://codereview.chromium.org/1523753002 .
Cr-Commit-Position: refs/heads/master@{#32929}
Reason for revert:
Breaks TSAN somewhow: http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/7000
Original issue's description:
> [es6] Correct Function.prototype.apply, Reflect.construct and Reflect.apply.
>
> Introduce a new Apply builtin that forms a correct and optimizable
> foundation for the Function.prototype.apply, Reflect.construct and
> Reflect.apply builtins (which properly does the PrepareForTailCall
> as required by the ES2015 spec).
>
> The new Apply builtin avoids going to the runtime if it is safe to
> just access the backing store elements of the argArray, i.e. if you
> pass a JSArray with no holes, or an unmapped, unmodified sloppy or
> strict arguments object.
>
> mips/mips64 ports by Balazs Kilvady <balazs.kilvady@imgtec.com>
>
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
> BUG=v8:4413, v8:4430
> LOG=n
> R=yangguo@chromium.org
>
> Committed: e4d2538911TBR=yangguo@chromium.org,paul.lind@imgtec.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4413, v8:4430
Review URL: https://codereview.chromium.org/1533803002 .
Cr-Commit-Position: refs/heads/master@{#32928}
Introduce a new Apply builtin that forms a correct and optimizable
foundation for the Function.prototype.apply, Reflect.construct and
Reflect.apply builtins (which properly does the PrepareForTailCall
as required by the ES2015 spec).
The new Apply builtin avoids going to the runtime if it is safe to
just access the backing store elements of the argArray, i.e. if you
pass a JSArray with no holes, or an unmapped, unmodified sloppy or
strict arguments object.
mips/mips64 ports by Balazs Kilvady <balazs.kilvady@imgtec.com>
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
BUG=v8:4413, v8:4430
LOG=n
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1523753002 .
Cr-Commit-Position: refs/heads/master@{#32927}
When the reviver returns undefined, the property in question must be deleted
even for arrays. So far this only happened for non-array objects.
Also change the property enumeration to be spec-conformant, which is observable when the reviver modifies its "this" object directly. There are a few further issues that need to be addressed in a separate CL.
R=yangguo@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1506933003
Cr-Commit-Position: refs/heads/master@{#32750}
This hackily disambiguates multiple calls for the iterator protocols in ForOf / Yield* by adding -2 / -1 to the pos.
BUG=v8:3953
LOG=y
Review URL: https://codereview.chromium.org/1491923003
Cr-Commit-Position: refs/heads/master@{#32527}
Section 8.10.5 9a specifies that a property descriptor cannot both have
accessors and specify the writability of the property. The previous
error message was misleading because it referred to writable rather
than specifying the writability (which includes writable: false).
BUG=v8:2536
LOG=N
Review URL: https://codereview.chromium.org/1399693003
Cr-Commit-Position: refs/heads/master@{#31273}
The previous hack with HInstanceOfKnownGlobal was not only slower,
but also very brittle and required a lot of weird hacks to support it. And
what's even more important it wasn't even correct (because a map check
on the lhs is never enough for instanceof).
The new implementation provides a sane runtime implementation
for InstanceOf plus a fast case in the InstanceOfStub, combined with
a proper specialization in the case of a known global in CrankShaft,
which does only the prototype chain walk (coupled with a code
dependency on the known global).
As a drive-by-fix: Also fix the incorrect Object.prototype.isPrototypeOf
implementation.
BUG=v8:4376
LOG=y
Review URL: https://codereview.chromium.org/1304633002
Cr-Commit-Position: refs/heads/master@{#30342}
Second item in section 13.7.5.1 states that the error should be a
SyntaxError, when previously CheckAndRewriteReferenceExpression
would always emit a ReferenceError.
BUG=v8:4373
R=adamk, rossberg
LOG=N
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1292393002
Cr-Commit-Position: refs/heads/master@{#30184}
This test enumerates properties on all the builtins and makes sure that
they never change. In practice, this just generates busywork when trying
to add new language features; I've never seen it catch an
accidentally-exposed bit of API.
Review URL: https://codereview.chromium.org/1275423006
Cr-Commit-Position: refs/heads/master@{#30160}
Duplicate parameters are banned both overall in strict mode and also
in arrow functions. Our error message for both cases blamed strict
mode, which is confusing. This patch fixes the message to point to
arrow functions as a possible source as well.
R=wingo, adamk
LOG=N
Review URL: https://codereview.chromium.org/1236863008
Cr-Commit-Position: refs/heads/master@{#29662}
For now it uses a pretty slow path for accessing strings by wrapping it into a new temporary wrapper.
BUG=v8:4042, v8:3088
LOG=y
Review URL: https://codereview.chromium.org/1221303019
Cr-Commit-Position: refs/heads/master@{#29576}
Turning the --harmony-array flag on has been delayed behind
unrelated test failures. Now that those tests are disabled,
land the changes.
This patch fixes WebKit tests based on the new change.
R=adamk
LOG=Y
BUG=v8:3578
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1199113003
Cr-Commit-Position: refs/heads/master@{#29209}
ES6 specs the function length property (it was not part of ES5) and
it makes it configurable.
BUG=v8:3045
LOG=N
R=mstarzinger@chromium.org, adamk@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/993073002
Cr-Commit-Position: refs/heads/master@{#27190}
Per TC39 Nov 2014 decision.
This patch also changes behavior for "legacy const": assignments to sloppy const in strict mode is now also a type error. This fixes v8:2243 and also brings us in compliance with other engines re assignment to function names (see updated webkit test), but might have bigger implications.
That change can easily be reverted by changing Variable::IsSignallingAssignmentToConst.
BUG=v8:3713,v8:2243
LOG=N
Review URL: https://codereview.chromium.org/749633002
Cr-Commit-Position: refs/heads/master@{#25516}
