The optimizing compilers actually invoke %TransitionElementsKind for
any kind of JSObject, the only relevant thing is the elements kind.
The runtime function was however checking for JSArray unnecessarily.
This only worked by coincindence in Crankshaft because the stub would
normally not call into the runtime fallback.
R=jarin@chromium.org
BUG=chromium:629823
Review-Url: https://codereview.chromium.org/2166963004
Cr-Commit-Position: refs/heads/master@{#37919}
This CL more or less reverts commit https://codereview.chromium.org/2107733002/
The use of the MathPow code stub that was introduced by that commit caused
problems on arm64, and the MathPow code stub was also an obstacle in the
implementation of parallel code generation.
In addition this CL turns on the mjsunit/wasm/embenchen tests for arm64
which were turned off because of problems with MathPow on arm64.
R=titzer@chromium.org, bradnelson@chromium.org
Review-Url: https://codereview.chromium.org/2166793002
Cr-Commit-Position: refs/heads/master@{#37911}
As required by the spec.
This is a variant of what I reverted in f47e722403.
It will probably still cause a regression but now it's easier to migrate (parts of)
the current implementation to C++, which is expected to make things faster again.
BUG=chromium:627729,v8:5113
Review-Url: https://codereview.chromium.org/2164923002
Cr-Commit-Position: refs/heads/master@{#37897}
This ports a large portion of Error methods to C++,
including the constructor, stack setter and getter,
and Error.prototype.toString.
BUG=
Review-Url: https://codereview.chromium.org/2142933003
Cr-Commit-Position: refs/heads/master@{#37870}
We need to pay attention to potential side effects from parameter
evaluation when inlining the fast case Array.prototype.shift.
R=yangguo@chromium.org
BUG=chromium:614644
Review-Url: https://codereview.chromium.org/2161943002
Cr-Commit-Position: refs/heads/master@{#37850}
Original issue's description:
> Don't compile functions in a context the caller doesn't have access to
>
> Instead just return undefined
>
> A side effect of this is that it's no longer possible to compile
> functions in a detached context.
>
> BUG=chromium:541703
> R=verwaest@chromium.org,bmeurer@chromium.org
BUG=chromium:541703
R=verwaest@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng
Review-Url: https://codereview.chromium.org/2155503004
Cr-Commit-Position: refs/heads/master@{#37842}
The bug occurs because we do not canonicalize character class ranges
before adding case equivalents. While adding case equivalents, we abort
early for one-byte subject strings, assuming that the ranges are sorted.
Which they are not.
R=marja@chromium.org
BUG=v8:5199
Review-Url: https://codereview.chromium.org/2159683002
Cr-Commit-Position: refs/heads/master@{#37833}
This makes sure that we preserve call's tailness even if we have
introduced a loop exit between the call and the return.
BUG=chromium:628773
Review-Url: https://codereview.chromium.org/2155123002
Cr-Commit-Position: refs/heads/master@{#37832}
In int32 multiplication, if we have a positive integer as input, then we know we can't produce a -0 answer. The same is true if truncation is applied (x * y | 0). Without this information, we have to rather annoyingly check if the result of multiplication is 0, then OR the inputs to check for negativity, and possibly return -0. In TurboFan, we'll deopt in this case.
BUG=
Review-Url: https://codereview.chromium.org/2154073002
Cr-Commit-Position: refs/heads/master@{#37831}
This fixes the deoptimization information for the lazy bailout point
after a [[ToObject]] operation inserted for with statements. The result
value was pushed on the operand stack but erroneously ignored and left
on the operand stack by the FullCodeGenerator.
R=jarin@chromium.org
TEST=mjsunit/regress/regress-5205
BUG=v8:5205
Review-Url: https://codereview.chromium.org/2158443002
Cr-Commit-Position: refs/heads/master@{#37818}
Delaying for merges caused branch cloning using dummy effect phi inputs,
potentially splitting the effect chain at start.
We still have to delay the creation for loops because we need to break
cycles.
BUG=chromium:628403
Review-Url: https://codereview.chromium.org/2159603002
Cr-Commit-Position: refs/heads/master@{#37808}
This reverts commit 457c02573c because it caused a
regression in SunSpider/string-fasta and possibly AreWeFastYet/Life. Need to
implement this in a smarter way.
TBR=littledan@chromium.org
BUG=chromium:627729,v8:5113
Review-Url: https://codereview.chromium.org/2149303003
Cr-Commit-Position: refs/heads/master@{#37793}
This makes sure that the uses of PlainPrimitiveToNumber get a more
precise type (so that the uses know how to interpret the output
representation).
BUG=chromium:628516
Review-Url: https://codereview.chromium.org/2151223002
Cr-Commit-Position: refs/heads/master@{#37792}
- Add Simd128 type to Wasm AST types
- Add a pass that converts SIMD machine ops to runtime calls
- Sample opcodes Int32x4Splat, Int32x4ExtractLane and test
- Separate out generic SIMD Machine ops as these cannot be
handled by runtime functions just yet.
LOG=N
BUG=v8:4124
R=bradnelson@chromium.org, bbudge@chromium.org, titzer@chromium.org
Review-Url: https://codereview.chromium.org/1991143002
Cr-Commit-Position: refs/heads/master@{#37789}
Annex B.3.3 of the spec requires that sloppy-mode block-scoped functions
declared by "eval" are hoisted unless doing so would cause an early
error (which is to say, conflict with a lexical declaration). This patch
amends the check for conflicting declarations to include those outside
of the eval itself.
BUG=v8:4468, v8:4479
Review-Url: https://codereview.chromium.org/2112163002
Cr-Commit-Position: refs/heads/master@{#37783}
Instead of unconditionally parsing the catch parameter as an expression
and then recovering if it turns out to be a simple variable proxy
(the overwhelmingly common case), this patch peeks one token ahead
before attempting to parse. This avoids doing the usual RemoveUnresolved
gymnastics in ParseTryStatement, and as a side-effect slightly improves
function name inference for an async arrow function test case.
Review-Url: https://codereview.chromium.org/2151433005
Cr-Commit-Position: refs/heads/master@{#37780}
Implemented the WebAssembly.Module and WebAssembly.Instance
in terms of the WasmModule::CompileFunctions and
WasmModule::Instantiate APIs.
Added negative tests - for invalid module object.
BUG=
Review-Url: https://codereview.chromium.org/2121593002
Cr-Commit-Position: refs/heads/master@{#37775}
Typed lowering now produces SpeculativeNumberShiftLeft for JSShiftLeft if the type feedback is kSignedSmall or kSigned32.
BUG=v8:4583
LOG=n
Review-Url: https://codereview.chromium.org/2150553002
Cr-Commit-Position: refs/heads/master@{#37762}
Reason for revert:
blink is unhappy about the microtask change
Original issue's description:
> Reland "Don't compile functions in a context the caller doesn't have access to"
>
> Original issue's description:
> > Don't compile functions in a context the caller doesn't have access to
> >
> > Instead just return undefined
> >
> > A side effect of this is that it's no longer possible to compile
> > functions in a detached context.
> >
> > BUG=chromium:541703
> > R=verwaest@chromium.org,bmeurer@chromium.org
>
> BUG=chromium:541703
> R=verwaest@chromium.org
>
> Committed: https://crrev.com/6bceabac5b705b2ce1f52d34650cea1ae3b8c617
> Cr-Commit-Position: refs/heads/master@{#37756}
TBR=verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:541703
Review-Url: https://codereview.chromium.org/2151843002
Cr-Commit-Position: refs/heads/master@{#37760}
Using the Hydrogen code stub bailout mechanism is not correct for the
string length overflow check in the StringAddStub. Instead make sure we
just throw the proper exception.
R=mstarzinger@chromium.org
BUG=chromium:627934
Review-Url: https://codereview.chromium.org/2146353002
Cr-Commit-Position: refs/heads/master@{#37758}
This adds a missing conversion of time zone names to string primitives
before case conversion and regular expression matching are applied.
This is in sync with ECMA-402, section 12.1.1.1, step 16(a).
R=jochen@chromium.org
TEST=mjsunit/regress/regress-crbug-627935
BUG=chromium:627935
Review-Url: https://codereview.chromium.org/2143003005
Cr-Commit-Position: refs/heads/master@{#37757}
Original issue's description:
> Don't compile functions in a context the caller doesn't have access to
>
> Instead just return undefined
>
> A side effect of this is that it's no longer possible to compile
> functions in a detached context.
>
> BUG=chromium:541703
> R=verwaest@chromium.org,bmeurer@chromium.org
BUG=chromium:541703
R=verwaest@chromium.org
Review-Url: https://codereview.chromium.org/2143893005
Cr-Commit-Position: refs/heads/master@{#37756}
Reason for revert:
Causes crashes on Canary
Original issue's description:
> Don't compile functions in a context the caller doesn't have access to
>
> Instead just return undefined
>
> A side effect of this is that it's no longer possible to compile
> functions in a detached context.
>
> BUG=chromium:541703
> R=verwaest@chromium.org,bmeurer@chromium.org
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng
>
> Committed: https://crrev.com/992e34c21635b179a993b82ac1d81753e7a6a57a
> Cr-Commit-Position: refs/heads/master@{#37657}
TBR=bmeurer@chromium.org,verwaest@chromium.org,jochen@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:541703, chromium:628053
Review-Url: https://codereview.chromium.org/2148163002
Cr-Commit-Position: refs/heads/master@{#37736}
The runtime JIT function is passed in the function table to hook up the compiled code and the starting address of the memory to locate the bytes to be compiled.
BUG=5044
Review-Url: https://codereview.chromium.org/2137993003
Cr-Commit-Position: refs/heads/master@{#37735}
Reason for revert:
Correcting issue.
Original issue's description:
> Revert of Add errors for declarations which conflict with catch parameters. (patchset #6 id:100001 of https://codereview.chromium.org/2109733003/ )
>
> Reason for revert:
> Fuzzer claims `try { \"\" ; } catch(x) { let x1 = [1,,], x = x; }` causes a crash.
>
> Original issue's description:
> > Add errors for declarations which conflict with catch parameters.
> >
> > Catch parameters are largely treated as lexical declarations in the
> > block which contains their body for the purposes of early syntax errors,
> > with some exceptions outlined in B.3.5. This patch introduces most of
> > those errors, except those from `eval('for (var e of ...);')` inside of
> > a catch with a simple parameter named 'e'.
> >
> > Note that annex B.3.5 allows var declarations to conflict with simple
> > catch parameters, except when the variable declaration is the init of a
> > for-of statement.
> >
> > BUG=v8:5112,v8:4231
> >
> > Committed: https://crrev.com/2907c726b2bb5cf20b2bec639ca9e6a521585406
> > Cr-Commit-Position: refs/heads/master@{#37462}
>
> TBR=littledan@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:5112,v8:4231
>
> Committed: https://crrev.com/8834d5ecb559001c87c42322969471da60574a8c
> Cr-Commit-Position: refs/heads/master@{#37464}
R=littledan@chromium.org
BUG=v8:5112,v8:4231
Review-Url: https://codereview.chromium.org/2119933002
Cr-Commit-Position: refs/heads/master@{#37728}
* Rename Atomics.futexWait -> Atomics.wait
* Rename Atomics.futexWake -> Atomics.wake
* Remove Atomics.futexWakeOrRequeue
* Return value of Atomics.wait is now a string: "ok", "not-equal" or
"timed-out"
* Update comments that reference URL for ecmascript_sharedmem to
https://github.com/tc39/ecmascript_sharedmem
Review-Url: https://codereview.chromium.org/2143443002
Cr-Commit-Position: refs/heads/master@{#37727}
This fixes the deoptimization information for the lazy bailout point
after a [[ToName]] operation inserted for object literals and class
literals. The result value was erroneously ignored.
R=jarin@chromium.org
TEST=mjsunit/regress/regress-crbug-627828
BUG=chromium:627828
Review-Url: https://codereview.chromium.org/2149493003
Cr-Commit-Position: refs/heads/master@{#37719}
This fully deprecates all uses of the RUNTIME_ASSERT macro and removes
the macro and underlying logging function in question. All uses have
been replaces with CHECK macros which crash safely even in production.
It makes sure we discover abuse of runtime functions in the wild early
and also abort the process safely. Breaking assumptions in any runtime
function can no longer accidentally be caught by JavaScript.
R=yangguo@chromium.org
BUG=v8:5066
Review-Url: https://codereview.chromium.org/2132493002
Cr-Commit-Position: refs/heads/master@{#37704}
This makes sure the {AstGraphBuilder} respects the catch-prediction that
is provided by the parser along with each {TryStatement}. This is needed
for try-blocks materialized by the parser not to influence predictions
users expect when using the debugger.
R=neis@chromium.org
TEST=mjsunit/debug-exceptions
BUG=v8:5183
Review-Url: https://codereview.chromium.org/2147573002
Cr-Commit-Position: refs/heads/master@{#37702}
Collect type feedback in the call bytecode handler. The current
implementation only collects feedback for JS function objects. The other
objects and Array functions do not collect any feedback. They will be
marked Megamorphic.
BUG=v8:4280, v8:4780
LOG=N
Review-Url: https://codereview.chromium.org/2122183002
Cr-Commit-Position: refs/heads/master@{#37700}
This solves an issue with throws inside for-of always being marked as caught.
BUG=v8:5183
Review-Url: https://codereview.chromium.org/2146493002
Cr-Commit-Position: refs/heads/master@{#37686}
- check that packed elements do not contain the_hole (with fix)
- verify argument objects with elements kind
- use JSObjectVerifiy in all JSObject "subclasses"
- change initialization order for ArrayLiteralBoilerplate to simplify verification
BUG=v8:5188
Review-Url: https://codereview.chromium.org/2126613002
Cr-Commit-Position: refs/heads/master@{#37680}
This removes the checking for use-def and def-use chain links from the
graph verification. Presence of such links can only be violated by a bug
in the actual {Node} implementation itself. That container class is also
covered by unit tests.
The verification in question was useful in the early days when the graph
implementation itself was prone to bugs. By now it has stabilized and
spending O(n^2) time during graph verification is too wasteful to still
be considered a reasonable trade-off.
R=jarin@chromium.org
TEST=unittests/NodeTest.*
Review-Url: https://codereview.chromium.org/2140973003
Cr-Commit-Position: refs/heads/master@{#37670}
Remove obsolete definitions from macros.py, and drop the now obsolete
%_ToPrimitive, %_ToPrimitive_Number, %_ToPrimitive_String, %_ToName
and the %ToPrimitive_String intrinsics/runtime entries.
R=yangguo@chromium.org
BUG=v8:5049
Review-Url: https://codereview.chromium.org/2137203002
Cr-Commit-Position: refs/heads/master@{#37665}
Instead just return undefined
A side effect of this is that it's no longer possible to compile
functions in a detached context.
BUG=chromium:541703
R=verwaest@chromium.org,bmeurer@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng
Review-Url: https://codereview.chromium.org/2034083002
Cr-Commit-Position: refs/heads/master@{#37657}
This patch just checks for a stack overflow and returns failure
from the cases which Clusterfuzz found. However, there may be
more locations in the parser which need similar treatment.
R=caitpotter88@gmail.com,neis
BUG=v8:4483,chromium:624300
Review-Url: https://codereview.chromium.org/2135503002
Cr-Commit-Position: refs/heads/master@{#37655}
CallSite::IsConstructor() was unable to recognize builtin construct stubs
(NumberConstructor_ConstructStub and StringConstructor_ConstructStub) as
constructors, and thus these frames were not formatted correctly in stack
traces.
Fix this by explicitly marking their Code objects as construct stubs and
passing along a special receiver value when we encounter such cases in
CaptureSimpleStackTrace.
R=mstarzinger@chromium.org, yangguo@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2125163004
Cr-Commit-Position: refs/heads/master@{#37631}
This enables tests which rely on the context available at "debugger"
statements to be accurate. This is the case by now when deoptimization
information is available.
R=yangguo@chromium.org
BUG=v8:4055
Review URL: https://codereview.chromium.org/2129123002 .
Cr-Commit-Position: refs/heads/master@{#37604}
Drive-by-fix: hydrogen code does not blindly return the
byteLength offset, instead it executes what is defined
in the byteLength getter.
BUG=
Review-Url: https://codereview.chromium.org/2123263002
Cr-Commit-Position: refs/heads/master@{#37595}
This enables tests which rely on the context available at "debugger"
statements to be accurate. This is the case by now when deoptimization
information is available.
R=mvstanton@chromium.org
BUG=v8:4035
Review-Url: https://codereview.chromium.org/2125773005
Cr-Commit-Position: refs/heads/master@{#37590}
When reading the value property of an iterator result fails, we must not close the iterator.
This was not discovered earlier because the tests had a subtle bug.
This CL fixes both the desugaring and the tests.
BUG=
Review-Url: https://codereview.chromium.org/2119353002
Cr-Commit-Position: refs/heads/master@{#37571}
For variables introduced as part of a catch pattern, we used to set their
"initializer position" to the beginning of the pattern. This lead to
full-codegen eliminating crucial hole checks when reading such variables
inside the pattern itself.
R=adamk@chromium.org, littledan@chromium.org
BUG=v8:5178
Review-Url: https://codereview.chromium.org/2123953002
Cr-Commit-Position: refs/heads/master@{#37569}
While the test was useful to reproduce the issue locally it creates a lot of
heap pressure and causes all sorts of troubles (OOM, slowness) on the bots, so
let's drop it.
R=hpayer@chromium.org
Review-Url: https://codereview.chromium.org/2127803002
Cr-Commit-Position: refs/heads/master@{#37551}
This removes explicit uses of the RUNTIME_ASSERT macro from some runtime
methods. The implicit ones in CONVERT_FOO_ARG_CHECKED will be addressed
in a separate CL for all runtime modules at once.
R=yangguo@chromium.org
BUG=v8:5066
Review-Url: https://codereview.chromium.org/2053573004
Cr-Commit-Position: refs/heads/master@{#37545}
This is a quick fix for the hole leaking from generators via the debugger's frame
inspection feature: when collecting the arguments, convert each hole to undefined.
In the long term, we probably want to remember and restore the actual arguments
rather than pushing these dummy arguments on each resume.
BUG=v8:5164
Review-Url: https://codereview.chromium.org/2122923003
Cr-Commit-Position: refs/heads/master@{#37544}
The dependency would only happen if we have a smi overflow for the length and
have create a heap number. In this case the heap number would've to survive
until the array buffer is collected.
To avoid this dependency we track the length (as we previously used to).
BUG=chromium:625752
LOG=N
TEST=test/mjsunit/regress/regress-625752.js
R=hpayer@chromium.org
This reverts commit 1791d7bb9a.
Review-Url: https://codereview.chromium.org/2127643002
Cr-Commit-Position: refs/heads/master@{#37537}
Reason for revert:
[Sheriff] This makes mjsunit/regress/regress-625752 extremely slow on all gc stress bots and leads to timeouts with custom snapshot:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/6602
Original issue's description:
> [heap] Track length for array buffers to avoid free-ing dependency
>
> The dependency would only happen if we have a smi overflow for the length and
> have create a heap number. In this case the heap number would've to survive
> until the array buffer is collected.
>
> To avoid this dependency we track the length (as we previously used to).
>
> BUG=chromium:625748,chromium:625752
> LOG=N
> TEST=test/mjsunit/regress/regress-625752.js
> R=hpayer@chromium.org
>
> Committed: https://crrev.com/ddc75cc1356a58b6cfd63f9da0586e1150496b3d
> Cr-Commit-Position: refs/heads/master@{#37530}
TBR=hpayer@chromium.org,mlippautz@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:625748,chromium:625752
Review-Url: https://codereview.chromium.org/2127483003
Cr-Commit-Position: refs/heads/master@{#37533}
The dependency would only happen if we have a smi overflow for the length and
have create a heap number. In this case the heap number would've to survive
until the array buffer is collected.
To avoid this dependency we track the length (as we previously used to).
BUG=chromium:625748,chromium:625752
LOG=N
TEST=test/mjsunit/regress/regress-625752.js
R=hpayer@chromium.org
Review-Url: https://codereview.chromium.org/2122603004
Cr-Commit-Position: refs/heads/master@{#37530}
This drops the %_ValueOf intrinsic, but keeps the runtime entry
%ValueOf for now, by either migrating the functionality (mostly
Debug mirror or toString/valueOf methods) to C++ or TurboFan
builtins, or switching to the %ValueOf runtime call when it's
not performance critical anyways.
The %_ValueOf intrinsic was one of the last blockers for fixing
the unsound machine operator typing in TurboFan.
R=yangguo@chromium.org
BUG=v8:5049
Committed: https://crrev.com/293bd7882987f00e465710ce468bfb1eaa7d3fa2
Review-Url: https://codereview.chromium.org/2126453002
Cr-Original-Commit-Position: refs/heads/master@{#37512}
Cr-Commit-Position: refs/heads/master@{#37519}
Reason for revert:
[Sheriff] Breaks without i18n:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20noi18n%20-%20debug/builds/8466
Original issue's description:
> [intrinsic] Drop the %_ValueOf intrinsic.
>
> This drops the %_ValueOf intrinsic, but keeps the runtime entry
> %ValueOf for now, by either migrating the functionality (mostly
> Debug mirror or toString/valueOf methods) to C++ or TurboFan
> builtins, or switching to the %ValueOf runtime call when it's
> not performance critical anyways.
>
> The %_ValueOf intrinsic was one of the last blockers for fixing
> the unsound machine operator typing in TurboFan.
>
> R=yangguo@chromium.org
> BUG=v8:5049
>
> Committed: https://crrev.com/293bd7882987f00e465710ce468bfb1eaa7d3fa2
> Cr-Commit-Position: refs/heads/master@{#37512}
TBR=yangguo@chromium.org,bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5049
Review-Url: https://codereview.chromium.org/2117273002
Cr-Commit-Position: refs/heads/master@{#37514}
This concerns formatting of calls to, e.g., Math.acos in stack traces,
in which the receiver is an object with an attached toString tag. If
such a tag exists, use it to format the receiver typename to ensure that
the stack trace includes 'Math.acos' instead of 'Object.acos'.
R=yangguo@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2110683007
Cr-Commit-Position: refs/heads/master@{#37513}
This drops the %_ValueOf intrinsic, but keeps the runtime entry
%ValueOf for now, by either migrating the functionality (mostly
Debug mirror or toString/valueOf methods) to C++ or TurboFan
builtins, or switching to the %ValueOf runtime call when it's
not performance critical anyways.
The %_ValueOf intrinsic was one of the last blockers for fixing
the unsound machine operator typing in TurboFan.
R=yangguo@chromium.org
BUG=v8:5049
Review-Url: https://codereview.chromium.org/2126453002
Cr-Commit-Position: refs/heads/master@{#37512}
Stack trace generation requires access to the receiver; and while the
receiver is already on the stack, we cannot determine its position
during stack trace generation (it's stored in argv[0], and argc is only
stored in a callee-saved register).
This patch grants access to the receiver by pushing argc onto builtin
exit frames as an extra argument. Compared to simply pushing the
receiver, this requires an additional dereference during stack trace
generation, but one fewer during builtin calls.
BUG=v8:4815
Review-Url: https://codereview.chromium.org/2106883003
Cr-Commit-Position: refs/heads/master@{#37500}
The re-typer now only types a node if its inputs are all typed with the
exception of phi nodes. This works because all cycles in the graph have
to contain a phi node.
BUG=chromium:625558
Review-Url: https://codereview.chromium.org/2120243002
Cr-Commit-Position: refs/heads/master@{#37493}
This patch implements "immutable prototype exotic objects" from the ECMAScript
spec, which are objects whose __proto__ cannot be changed, but are not otherwise
frozen. They are introduced in order to prevent a Proxy from being introduced
to the prototype chain of the global object.
The API is extended by a SetImmutablePrototype() call in ObjectTemplate, which
can be used to vend new immutable prototype objects. Additionally, Object.prototype
is an immutable prototype object.
In the implementation, a new bit is added to Maps to say whether the prototype is
immutable, which is read by SetPrototype. Map transitions to the immutable prototype
state are not saved in the transition tree because the main use case is just for
the prototype chain of the global object, which there will be only one of per
Context, so no need to take up the extra word for a pointer in each full transition
tree.
BUG=v8:5149
Review-Url: https://codereview.chromium.org/2108203002
Cr-Commit-Position: refs/heads/master@{#37482}
This makes the elimination of checkpoints flowing effect-wise into nodes
having the {Return} operator more permissive. We can cut out checkpoints
even when they are not wholly owned by the return. This also alleviates
a problem where TCO no longer applies.
R=jarin@chromium.org
TEST=mjsunit/regress/regress-crbug-624747
BUG=chromium:624747
Review-Url: https://codereview.chromium.org/2118793002
Cr-Commit-Position: refs/heads/master@{#37480}
