This relands squashed CLs:
59b9aaf7db8f84d0bb8f
The revert was at crrev.com/c/2996198.
Changed: Fixed a test in which bytecode flushing caused a behavioral
change between serialized- and unserialized SFI Refs. The serialized
SFI ref kept bytecode alive while unserialized SFIs allow flushing.
The test was fixed by adding a %PrepareFunctionForOptimization
annotation.
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7790, v8:11939
Change-Id: I170f8085bd7454a2a5f2bb03c8824e2862857827
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2999089
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75504}
https://github.com/tc39/ecma262/pull/1490 changed the spec so that the
"name" property of a class should be installed after "length" but before
"prototype". This CL adapts accordingly.
After this change, there is now no need for the separate code path to
set the "name" accessor at runtime. Delete the relevant runtime code as
well.
Bug: v8:8771
Change-Id: I8f809b45bf209c899cf5df76d0ebf6d9a45a6d4e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2974772
Commit-Queue: Timothy Gu <timothygu@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75340}
This isn't used outside of tests, so let's just remove it.
Change-Id: I06b7ec11911fd8ebc3bbabcba16d0c2a3fafddab
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2968413
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75220}
This CL is part of a series that implements Turbofan support for
property accesses satisfying the following conditions:
1. The holder is a dictionary mode object.
2. The holder is a prototype.
3. The access is a load.
This feature will only be enabled if the build flag
v8_dict_property_const_tracking is set.
This particular CL modifies existing mjsunit tests whose assumptions
don't hold if v8_dict_property_const_tracking is enabled. This is
done by adding special handling for the case that
%IsDictPropertyConstTrackingEnabled() holds.
Bug: v8:11248
Change-Id: Ia36be73e4659a988b2471f0c8151b0442f3a98f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2780292
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73745}
This flag enables feedback allocation heuristics to be based on the
function size. The threshold for feedback allocation is set to
12 * bytecode size to roughly mimic the allocation after 12 invocations.
We tried 4 * bytecode size earlier and there were few memory regressions
on real world pages. Speedometer improved by ~1% [1, 2]. This time
trying with a higher factor this time to see if we still have
speedometer improvements without any memory regressions.
[1] https://bugs.chromium.org/p/chromium/issues/detail?id=1177124
[2] https://bugs.chromium.org/p/chromium/issues/detail?id=1177241
Change-Id: I39c7d4aaf90b948b07419e4598e2193b8355c067
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2752150
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73369}
This is a reland of cf93071c91
Original change's description:
> [interpreter] Short Star bytecode
>
> Design doc:
> https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
>
> This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
> that we can use a single byte to represent the common operation of
> storing to a low-numbered register. This generally reduces the quantity
> of bytecode generated on web sites by 8-9%.
>
> In order to not degrade speed, a couple of other changes are required:
>
> The existing lookahead logic to check for Star after certain other
> bytecode handlers is updated to check for these new short Star codes
> instead. Furthermore, that lookahead logic is updated to contain its own
> copy of the dispatch jump rather than merging control flow with the
> lookahead-failed case, to improve branch prediction.
>
> A bunch of constants use bytecode size in bytes as a proxy for the size
> or complexity of a function, and are adjusted downward proportionally to
> the decrease in generated bytecode size.
>
> Other small drive-by fix: update generate-bytecode-expectations to emit
> \n instead of \r\n on Windows.
>
> Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#72773}
Change-Id: I1afb670c25694498b3989de615858f984a8c7f6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2698057
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72821}
Sparkplug is a new baseline, non-optimising second-tier compiler,
designed to fit in the compiler trade-off space between Ignition and
TurboProp/TurboFan.
Design doc:
https://docs.google.com/document/d/13c-xXmFOMcpUQNqo66XWQt3u46TsBjXrHrh4c045l-A/edit?usp=sharing
Bug: v8:11420
Change-Id: Ideb7270db3d6548eedd8337a3f596eb6f8fea6b1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2667514
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72686}
Fix 1: Track Scope::needs_home_object and Scope::uses_super_property
accurately. When "eval" is seen, figure out whether it can access
"super" and if yes, set the corresponding home object as needed.
Fix 2: The object literal scope shouldn't be entered for things
inside spreads.
Original: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
Previous reland: https://chromium-review.googlesource.com/c/v8/v8/+/2637220
This saves memory (the home object doesn't need to be stored for each
method, but only once per class) and hopefully makes the home object
a constant in the optimized code.
Detailed documentation of the changes:
https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing
Bug: v8:9237
Bug: chromium:1167918
Bug: chromium:1167981
Bug: chromium:1167988
Bug: chromium:1168055
Bug: chromium:1171195
Bug: chromium:1171600
Change-Id: I9686e0d90cd0c1128757eca440a88748897ee91e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2655509
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72422}
This reverts commit f6450b97ec.
Reason for revert: ClusterFuzz bugs
Original change's description:
> Reland [super] Store home object in Context instead of JSFunction
>
> 1) Computed property keys (esp functions in them) shouldn't be inside
> the object literal scope.
>
> 2) I was using an imprecise "maybe uses super" and storing it to
> preparse data. This won't fly, since it pollutes sister scopes and
> leads to confusion wrt whether an object literal needs a home object
> or not. Made it precise (mostly cancelling changes in the original CL).
>
> 3) PreParser::NewSuperPropertyReference was creating a VariableProxy for
> this_function (which made it used) -> inconsistent scopes between
> parsing and preparsing.
>
> 4) MultipleEntryBlockContextScope was messing up the accumulator
>
> Original: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
>
> This saves memory (the home object doesn't need to be stored for each
> method, but only once per class) and hopefully makes the home object
> a constant in the optimized code.
>
> Detailed documentation of the changes:
> https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing
>
> Bug: v8:9237, chromium:1167918, chromium:1167981, chromium:1167988, chromium:1168055
> Change-Id: I4f53f18cc18762c33e53d8c802909b42f1c33538
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637220
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Marja Hölttä <marja@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72169}
TBR=marja@chromium.org,leszeks@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:9237
Bug: chromium:1167918
Bug: chromium:1167981
Bug: chromium:1167988
Bug: chromium:1168055
Bug: chromium:1171195
Bug: chromium:1171600
Change-Id: I15209f50c3fc8acf385a23f031ebb64139e2f519
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2653158
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72391}
Currently, feedback vectors are allocated on a fixed budget of 1024.
In some cases it might be beneficial to allocate feedback vectors based
on invocation count rather than fixed budget. For example, if we have
a large function that is only run once. This cl adds an option to
use interrupt budget based on the bytecode size. It kind of mimics
invocation count. We would allocate feedback vectors early when we
have loops which is also required.
This flag is turned off by default. In followup cl, we will enable it
and if the memory / performance tradeoff is good we might make it
default.
Change-Id: I9f7231119b5fd65fb3268e665e2e315fb2625e1b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2584960
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72371}
1) Computed property keys (esp functions in them) shouldn't be inside
the object literal scope.
2) I was using an imprecise "maybe uses super" and storing it to
preparse data. This won't fly, since it pollutes sister scopes and
leads to confusion wrt whether an object literal needs a home object
or not. Made it precise (mostly cancelling changes in the original CL).
3) PreParser::NewSuperPropertyReference was creating a VariableProxy for
this_function (which made it used) -> inconsistent scopes between
parsing and preparsing.
4) MultipleEntryBlockContextScope was messing up the accumulator
Original: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
This saves memory (the home object doesn't need to be stored for each
method, but only once per class) and hopefully makes the home object
a constant in the optimized code.
Detailed documentation of the changes:
https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing
Bug: v8:9237, chromium:1167918, chromium:1167981, chromium:1167988, chromium:1168055
Change-Id: I4f53f18cc18762c33e53d8c802909b42f1c33538
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637220
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72169}
This reverts commit 4d5b878b61.
Reason for revert: Suspected to cause a failure on ChromeOS, which is blocking the roll - https://chromium-review.googlesource.com/c/chromium/src/+/2636263
Original change's description:
> [super] Store home object in Context instead of JSFunction
>
> This saves memory (the home object doesn't need to be stored for each
> method, but only once per class) and hopefully makes the home object
> a constant in the optimized code.
>
> Detailed documentation of the changes:
> https://docs.google.com/document/d/1ZVXcoQdf9IdMsnRI9iyUjyq9NDoEyx9nA3XqMgwflMs/edit?usp=sharing
>
> Bug: v8:9237
> Change-Id: Ia0925bdc8bfe54cbefcba6d10f64746d63a530c7
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563275
> Commit-Queue: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72137}
TBR=marja@chromium.org,leszeks@chromium.org
Change-Id: Idc5a8240cef4da8893ccc608ee4ae0d7206a1ba8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9237
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637215
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72142}
This implements the spec change in
https://github.com/tc39/ecma262/pull/2164
Making TA elements configurable has interaction with delete. While
the elements are configurable, they are only "deletable" via detaching
the underlying ArrayBuffer, not via `delete`. That is, `delete ta[idx]`
for an in-bounds `idx` still returns false.
Bug: v8:11281
Change-Id: I2e9348a7ec3c3239a92cc35e51b7182423736834
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2605234
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71955}
AddToDictionaryTemplate in literal-objects.cc was missing several
cases when handling the overwriting between properties with statically
known and dynamically computed names. This led to wrong enumeration
orders in class prototypes created from class templates.
Bug: v8:11158
Change-Id: I7381b4680ec533bd307a6c32d75c8a66394869df
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2536464
Commit-Queue: Frank Emrich <emrich@google.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71266}
... to --turbo-dynamic-map-checks. With the upcoming use in NCI code,
this feature is no longer used exclusively by Turboprop.
Bug: v8:8888
Change-Id: I61e01db086fd2e8566d2e2a09574be74b6e5a7bd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2546693
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71263}
The tests assert that funcs are optimized / deoptimized a certain way.
Bug: v8:9237, v8:11138
Change-Id: Ia4879e722e442be52de0bf93919eb03fecb88147
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2529136
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71087}
This reverts commit 0147db5a4a.
Reason for revert: Data races: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20TSAN/34056
Original change's description:
> [super] Optimize super property access in JSNativeContextSpecialization
>
> Generalize the existing property lookup machinery
> (JSNCS::ReduceNamedAccess) to handle the case where the
> lookup_start_object and the receiver are different objects.
>
> Design doc: https://docs.google.com/document/d/1b_wgtExmJDLb8206jpJol-g4vJAxPs1XjEx95hwRboI/edit#heading=h.xqthbgih7l2l
>
> Bug: v8:9237
> Change-Id: I28b6d87ce6537acd8cf972bbe7dc6d63d581aadc
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2487122
> Commit-Queue: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70988}
TBR=marja@chromium.org,mvstanton@chromium.org,neis@chromium.org
Change-Id: Ib5ddb919ae569fe5ddf266d986f1c8bc0fe9621a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9237
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2520908
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70992}
With non-super loads (receiver == lookup_start_object), we don't hit
the code in AccessorAssembler::GenericPropertyLoad calling
CSA::TryGetOwnProperty if the receiver (the lookup_start_object) is a
SMI.
But with super property loads, if we set up lookup_start_object the
right way, we will hit this code.
The code was assuming receiver is a HeapObject, which is too
restrictive. The receiver is only used for the accessor call, so
it's ok to make the type more generic.
Bug: v8:9237, chromium:1139786
Change-Id: I3167ccfb54a49ac1c401040a6f02fc1f3b98d9d1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2484366
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70647}
The actual fix is in LoadIC::ComputeHandler (checking
lookup_start_object == holder instead of receiver == holder) + the
LookupIterator changes for preserving lookup_start_object.
The rest is renaming / refactoring.
Reland: not relying on the prototype validity cell after all
Previous version: https://chromium-review.googlesource.com/c/v8/v8/+/2414039
Bug: v8:9237, chromium:1127653
Change-Id: I1949442f8ddcecb776f0c5d2cf737cb75f80e313
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2428588
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70112}
This fixes a case in which we forgot to assign flags to TextNodes
created through
AddBmpCharacters
AddNonBmpSurrogatePairs
AddLoneLeadSurrogates
AddLoneTrailSurrogates
functions. If these initially had a flag (e.g. case-insensitive 'i')
set, that information was lost. This bug resulted in missing case
folding in no_i18n builds (perhaps other things as well that just
aren't covered by our test suite).
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Bug: v8:10131,v8:10120
Change-Id: Icef4f0dbd47971a538e07bab2f1067c383fd59c6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2423718
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70106}
The actual fix is in LoadIC::ComputeHandler (checking
lookup_start_object == holder instead of receiver == holder) + the
LookupIterator changes for preserving lookup_start_object.
The rest is renaming / refactoring.
Bug: v8:9237, chromium:1127653
Change-Id: Ieef46fb46ababa79623951c48639429c5b552d2d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414039
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70045}
With this CL d8 exits with an error code if there is an unhandled
promise rejection, e.g. due tue a failed assertion in a promise. Up
until now these assertions were just ignored.
Bug: v8:10556
Change-Id: I25f20e4be45a2de130562deb15f6a144f0ac976f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2238569
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68503}
This changes black/white list to block/allow list.
Bug: v8:10619
Change-Id: Id55d72f90891670ca57b62dfeb6b3251025927dc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2257228
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68464}
Promise.{all,allSettled,any,race} should check resolve is a function before
opening their iteratable.
PR: https://github.com/tc39/ecma262/pull/1912
PR for Promise.any: https://github.com/tc39/proposal-promise-any/pull/65
This CL includes the following cleanup changes:
- Made it more explicit that the constructor is a Constructor.
- Removed unnecessary nested try blocks (a try can have both a catch and a label).
- Moved commonly used definitions out of promise-race.tq where they don't belong.
- Made the parameter order of PerformPromiseAll match the spec.
Bug: v8:10578
Change-Id: I9deb5d5106db7350a0d0ad52f165ff2469e7074b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2232544
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68260}
Since ES6, optional arguments are treated the same as undefined. This
was recently cleaned up in https://github.com/tc39/ecma262/pull/1411.
The current Torque implementation of %TypedArray%.from incorrectly
interpreted the old (and confusing) language of a parameter being "not
present" as testing using arguments.length instead of testing directly
for undefined.
Bug: v8:10458
Change-Id: I055f1fa3be570a31a4f7369ba5b51b7d6b022f0a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2168674
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67454}
PerformPromiseAll doesn't set iteratorRecord.[[Done]] to true if
Promise.resolve is not callable. This makes Promise.all call
IteratorClose.
BUG=v8:10452
Change-Id: Icbe17416a733f68ef09f1c610d715f544c2a3b8a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2164789
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67416}
This is a reland of 29c1eab92e
Original change's description:
> [builtins] Clean up the use of class_name / ES5 [[Class]]
>
> Before ES2015, the ES spec had a [[Class]] internal slot for all
> objects, which Object.prototype.toString() would use to figure the
> returned string. Post-ES2015, the [[Class]] slot was removed in spec for
> all objects, with the @@toStringTag well-known symbol the proper way to
> change Object.prototype.toString() output.
>
> At the time, spec-identical handling without the use of [[Class]] was
> implemented in V8 for all objects other than API objects, where issues
> with the Web IDL spec [1] prevented Blink, and hence V8, to totally
> migrate to @@toStringTag. However, since 2016 [2] Blink has been setting
> @@toStringTag on API class prototypes to manage the
> Object.prototype.toString() output, so the legacy [[Class]] handling in
> V8 has not been necessary for the past couple of years.
>
> This CL removes the remaining legacy [[Class]] handling in
> Object.prototype.toString(), JSReceiver::class_name(), and
> GetConstructorName(). However, it does not remove the class_name field
> in FunctionTemplateInfo, as it is still used for the `name` property of
> created functions.
>
> This CL also cleans up other places in the codebase that still reference
> [[Class]].
>
> This change should have minimal impact on web-compatibility. For the
> change to be observable, a script must do one of the following:
>
> 1. delete APIConstructor.prototype[Symbol.toStringTag];
> 2. Object.setPrototypeOf(apiObject, somethingElse);
>
> Before this CL, these changes will not change the apiObject.toString()
> output. But after this CL, they will make apiObject.toString() show
> "[object Object]" (in the first case) or the @@toStringTag of the other
> prototype (in the latter case).
>
> However, both are deemed unlikely. @@toStringTag is not well-known
> feature of JavaScript, nor does it get tampered much on API
> constructors. In the second case, setting the prototype of an API object
> would effectly render the object useless, as all its methods (including
> property getters/setters) would no longer be accessible.
>
> Currently, @@toStringTag-based API object branding is not yet
> implemented by other browsers. This V8 bug in particular has been an
> impediment to standardizing toString behavior. Fixing this bug will
> unblock [3] and lead to a better Web IDL spec, and better toString()
> compatibility for all.
>
> [1]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=28244
> [2]: https://crrev.com/909c0d7d5a53c8526ded351683c65ea7d17531d4
> [3]: https://github.com/heycam/webidl/pull/357
>
> Bug: chromium:793406
> Cq-Include-Trybots: luci.chromium.try:linux-rel
> Change-Id: Iceded24e37afa2646ec385d5018909f55b177f93
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2146996
> Commit-Queue: Timothy Gu <timothygu@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67327}
Bug: chromium:793406
Change-Id: Ia5d97bd4e1c44cadc6f18a17ffc9d06b038cf8f1
Cq-Include-Trybots: luci.chromium.try:linux-rel
Cq-Include-Trybots: luci.v8.try:v8_linux_blink_rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2163881
Auto-Submit: Timothy Gu <timothygu@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67361}
This reverts commit 29c1eab92e.
Reason for revert: Causes Blink test failures:
https://ci.chromium.org/p/v8/builders/ci/V8%20Blink%20Linux/4222
Original change's description:
> [builtins] Clean up the use of class_name / ES5 [[Class]]
>
> Before ES2015, the ES spec had a [[Class]] internal slot for all
> objects, which Object.prototype.toString() would use to figure the
> returned string. Post-ES2015, the [[Class]] slot was removed in spec for
> all objects, with the @@toStringTag well-known symbol the proper way to
> change Object.prototype.toString() output.
>
> At the time, spec-identical handling without the use of [[Class]] was
> implemented in V8 for all objects other than API objects, where issues
> with the Web IDL spec [1] prevented Blink, and hence V8, to totally
> migrate to @@toStringTag. However, since 2016 [2] Blink has been setting
> @@toStringTag on API class prototypes to manage the
> Object.prototype.toString() output, so the legacy [[Class]] handling in
> V8 has not been necessary for the past couple of years.
>
> This CL removes the remaining legacy [[Class]] handling in
> Object.prototype.toString(), JSReceiver::class_name(), and
> GetConstructorName(). However, it does not remove the class_name field
> in FunctionTemplateInfo, as it is still used for the `name` property of
> created functions.
>
> This CL also cleans up other places in the codebase that still reference
> [[Class]].
>
> This change should have minimal impact on web-compatibility. For the
> change to be observable, a script must do one of the following:
>
> 1. delete APIConstructor.prototype[Symbol.toStringTag];
> 2. Object.setPrototypeOf(apiObject, somethingElse);
>
> Before this CL, these changes will not change the apiObject.toString()
> output. But after this CL, they will make apiObject.toString() show
> "[object Object]" (in the first case) or the @@toStringTag of the other
> prototype (in the latter case).
>
> However, both are deemed unlikely. @@toStringTag is not well-known
> feature of JavaScript, nor does it get tampered much on API
> constructors. In the second case, setting the prototype of an API object
> would effectly render the object useless, as all its methods (including
> property getters/setters) would no longer be accessible.
>
> Currently, @@toStringTag-based API object branding is not yet
> implemented by other browsers. This V8 bug in particular has been an
> impediment to standardizing toString behavior. Fixing this bug will
> unblock [3] and lead to a better Web IDL spec, and better toString()
> compatibility for all.
>
> [1]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=28244
> [2]: https://crrev.com/909c0d7d5a53c8526ded351683c65ea7d17531d4
> [3]: https://github.com/heycam/webidl/pull/357
>
> Bug: chromium:793406
> Cq-Include-Trybots: luci.chromium.try:linux-rel
> Change-Id: Iceded24e37afa2646ec385d5018909f55b177f93
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2146996
> Commit-Queue: Timothy Gu <timothygu@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#67327}
TBR=verwaest@chromium.org,timothygu@chromium.org
Change-Id: I678d2ffc1064b1d1ddb62024cc23c6c41b216ef4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:793406
Cq-Include-Trybots: luci.chromium.try:linux-rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2163956
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67349}
Before ES2015, the ES spec had a [[Class]] internal slot for all
objects, which Object.prototype.toString() would use to figure the
returned string. Post-ES2015, the [[Class]] slot was removed in spec for
all objects, with the @@toStringTag well-known symbol the proper way to
change Object.prototype.toString() output.
At the time, spec-identical handling without the use of [[Class]] was
implemented in V8 for all objects other than API objects, where issues
with the Web IDL spec [1] prevented Blink, and hence V8, to totally
migrate to @@toStringTag. However, since 2016 [2] Blink has been setting
@@toStringTag on API class prototypes to manage the
Object.prototype.toString() output, so the legacy [[Class]] handling in
V8 has not been necessary for the past couple of years.
This CL removes the remaining legacy [[Class]] handling in
Object.prototype.toString(), JSReceiver::class_name(), and
GetConstructorName(). However, it does not remove the class_name field
in FunctionTemplateInfo, as it is still used for the `name` property of
created functions.
This CL also cleans up other places in the codebase that still reference
[[Class]].
This change should have minimal impact on web-compatibility. For the
change to be observable, a script must do one of the following:
1. delete APIConstructor.prototype[Symbol.toStringTag];
2. Object.setPrototypeOf(apiObject, somethingElse);
Before this CL, these changes will not change the apiObject.toString()
output. But after this CL, they will make apiObject.toString() show
"[object Object]" (in the first case) or the @@toStringTag of the other
prototype (in the latter case).
However, both are deemed unlikely. @@toStringTag is not well-known
feature of JavaScript, nor does it get tampered much on API
constructors. In the second case, setting the prototype of an API object
would effectly render the object useless, as all its methods (including
property getters/setters) would no longer be accessible.
Currently, @@toStringTag-based API object branding is not yet
implemented by other browsers. This V8 bug in particular has been an
impediment to standardizing toString behavior. Fixing this bug will
unblock [3] and lead to a better Web IDL spec, and better toString()
compatibility for all.
[1]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=28244
[2]: https://crrev.com/909c0d7d5a53c8526ded351683c65ea7d17531d4
[3]: https://github.com/heycam/webidl/pull/357
Bug: chromium:793406
Cq-Include-Trybots: luci.chromium.try:linux-rel
Change-Id: Iceded24e37afa2646ec385d5018909f55b177f93
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2146996
Commit-Queue: Timothy Gu <timothygu@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67327}
For example, when --fuzzing is off, %OptimizeFunctionOnNextCall now
crashes when given a non-function argument.
The following behaviors remain unchanged for now:
- %DeoptimizeFunction continues to do nothing if the function is not
optimized.
- %DeoptimizeNow continues to do nothing if the top-most JS function
is not optimized.
- %OptimizeOSR continues to do nothing if the function already has
optimized code.
Bug: v8:10249
Change-Id: I35d2f3d50ce3f94c8ffccabe50fb4df2b70ce028
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2137406
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67121}