If DevTools is turned on in the middle of doing some things with async
functions, then more items may be popped from the Promise stack than were
pushed to it. In this sort of case, it's OK to have a catch misprediction,
but a crash is unacceptable. This patch defensively handles this edge
case where the Promise stack is unexpectedly empty for that reason.
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2361333003
Cr-Commit-Position: refs/heads/master@{#39705}
This patch tracks the stack of async functions differently from other
Promise async stack tracking. With this patch, the stack trace of a
callstack of async functions should look similarly to the call stack
if all of the functions were synchronous. An example can be found in
the updated test expectations: https://codereview.chromium.org/2362923002 .
The new stack traces are implemented using existing mechanisms in the
inspector. The inspector has two ways to save async stack traces: recurring
and non-recurring stacks. An example of a non-recurring stack is setTimeout,
and a recurring one is saved for setInterval. Recurring stacks are deleted
only when a special "cancel" function is called, rather than being deleted
after being used the first time. Previous Promise async stack tracking always
used non-recurring stacks.
For async functions, this patch saves a recurring stack. The top frame of
the stack is duplicated, as the resuming function contains a similar frame;
the devtools frontend is responsible for removing or marking this frame,
which it can do based on seeing the [async function] line which follows it.
The second frame will instead be provided by the resuming execution
context. The recurring stack is saved when the async function is entered, and
it is deleted from a finally block. The id of the stack is saved in the outer
Promise being constructed by the async function. When an intermediate
throwaway Promise will be triggered as a reaction, it will be identified as
such based on its debugging metadata, and the corresponding async function's
recurring stack will be used.
BUG=v8:4483
Review-Url: https://codereview.chromium.org/2357423002
Cr-Commit-Position: refs/heads/master@{#39695}
This patch knits together Promises returned by async/await such that when
one async function awaits the result of another one, catch prediction works
across the boundaries, whether the exception comes synchronously or
asynchronously. Edges are added in three places:
- When a locally uncaught await happens, if the value passed into await
is a Promise, from the awaited value to the Promise under construction
in the broader async function
- From a "throwaway" Promise, which may be found on the Promise debug
stack, to the Promise under construction in the async function that
surrounds it
- When a Promise is resolved with another Promise (e.g., when returning a
Promise from an async function)
In this reland, the caught tests are broken up into four parts to avoid
timeouts.
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2346363004
Cr-Commit-Position: refs/heads/master@{#39564}
Reason for revert:
Need to break up test into smaller tests to avoid timeouts
Original issue's description:
> Async/await Promise dependency graph
>
> This patch knits together Promises returned by async/await such that when
> one async function awaits the result of another one, catch prediction works
> across the boundaries, whether the exception comes synchronously or
> asynchronously. Edges are added in three places:
> - When a locally uncaught await happens, if the value passed into await
> is a Promise, from the awaited value to the Promise under construction
> in the broader async function
> - From a "throwaway" Promise, which may be found on the Promise debug
> stack, to the Promise under construction in the async function that
> surrounds it
> - When a Promise is resolved with another Promise (e.g., when returning a
> Promise from an async function)
>
> BUG=v8:5167
>
> Committed: https://crrev.com/7265fdde7c76b9f875b40b0b139515936d491d64
> Cr-Commit-Position: refs/heads/master@{#39522}
TBR=adamk@chromium.org,jgruber@chromium.org,kozyatinskiy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2351953002
Cr-Commit-Position: refs/heads/master@{#39523}
This patch knits together Promises returned by async/await such that when
one async function awaits the result of another one, catch prediction works
across the boundaries, whether the exception comes synchronously or
asynchronously. Edges are added in three places:
- When a locally uncaught await happens, if the value passed into await
is a Promise, from the awaited value to the Promise under construction
in the broader async function
- From a "throwaway" Promise, which may be found on the Promise debug
stack, to the Promise under construction in the async function that
surrounds it
- When a Promise is resolved with another Promise (e.g., when returning a
Promise from an async function)
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2317383002
Cr-Commit-Position: refs/heads/master@{#39522}
This patch closes a memory leak in async/await where the desugaring
was creating a situation analagous to that described in v8:5002.
Intermediate Promises were being kept alive, so a long-running loop
would cause linear memory usage on the heap. This patch returns
undefined to the 'then' callback passed into PerformPromiseThen
in order to avoid this hazard. Test expectations are fixed to remove
expecting extraneous events which occurred on Promises that are
now not given unnecessarily complex resolution paths before being
thrown away.
This patch is a reland; originally, tests which exercised the memory
exhaustion were checked in. Although it's possible to find good parameters
for running such tests locally, it is difficult to automate the tests
between the rock of timeouts and the hard place of too-small heaps
causing memory exhaustion in some modes even when there is no leak.
BUG=v8:5390
Review-Url: https://codereview.chromium.org/2352933002
Cr-Commit-Position: refs/heads/master@{#39520}
Reason for revert:
Still causes issues on bot (sometimes!)
Original issue's description:
> Reland of Fix async/await memory leak (patchset #1 id:1 of https://codereview.chromium.org/2354473002/ )
>
> Reason for revert:
> Relanding with faster-running test
>
> Original issue's description:
> > Revert of Fix async/await memory leak (patchset #5 id:80001 of https://codereview.chromium.org/2334323006/ )
> >
> > Reason for revert:
> > newly introduced test async-await-loop times out: https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/10894/steps/Ignition%20-%20turbofan%20%28flakes%29/logs/async-await-loop
> >
> > Original issue's description:
> > > Fix async/await memory leak
> > >
> > > This patch closes a memory leak in async/await where the desugaring
> > > was creating a situation analagous to that described in v8:5002.
> > > Intermediate Promises were being kept alive, so a long-running loop
> > > would cause linear memory usage on the heap. This patch returns
> > > undefined to the 'then' callback passed into PerformPromiseThen
> > > in order to avoid this hazard. Test expectations are fixed to remove
> > > expecting extraneous events which occurred on Promises that are
> > > now not given unnecessarily complex resolution paths before being
> > > thrown away.
> > >
> > > BUG=v8:5390
> > >
> > > Committed: https://crrev.com/a0ba18e9634c5e2d439033ab61a77cff54f9af35
> > > Cr-Commit-Position: refs/heads/master@{#39479}
> >
> > TBR=adamk@chromium.org,caitp@igalia.com,littledan@chromium.org
> > NOTRY=true
> > BUG=v8:5390
> >
> > Committed: https://crrev.com/196db1999da130019bbf8e3bd65977f840e8afaf
> > Cr-Commit-Position: refs/heads/master@{#39493}
>
> TBR=adamk@chromium.org,caitp@igalia.com,hablich@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> BUG=v8:5390
>
> Committed: https://crrev.com/e51482f01f26e0013e6377e85c4d2c41900e403c
> Cr-Commit-Position: refs/heads/master@{#39508}
TBR=adamk@chromium.org,caitp@igalia.com,hablich@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5390
Review-Url: https://codereview.chromium.org/2348403003
Cr-Commit-Position: refs/heads/master@{#39512}
Reason for revert:
Relanding with faster-running test
Original issue's description:
> Revert of Fix async/await memory leak (patchset #5 id:80001 of https://codereview.chromium.org/2334323006/ )
>
> Reason for revert:
> newly introduced test async-await-loop times out: https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/10894/steps/Ignition%20-%20turbofan%20%28flakes%29/logs/async-await-loop
>
> Original issue's description:
> > Fix async/await memory leak
> >
> > This patch closes a memory leak in async/await where the desugaring
> > was creating a situation analagous to that described in v8:5002.
> > Intermediate Promises were being kept alive, so a long-running loop
> > would cause linear memory usage on the heap. This patch returns
> > undefined to the 'then' callback passed into PerformPromiseThen
> > in order to avoid this hazard. Test expectations are fixed to remove
> > expecting extraneous events which occurred on Promises that are
> > now not given unnecessarily complex resolution paths before being
> > thrown away.
> >
> > BUG=v8:5390
> >
> > Committed: https://crrev.com/a0ba18e9634c5e2d439033ab61a77cff54f9af35
> > Cr-Commit-Position: refs/heads/master@{#39479}
>
> TBR=adamk@chromium.org,caitp@igalia.com,littledan@chromium.org
> NOTRY=true
> BUG=v8:5390
>
> Committed: https://crrev.com/196db1999da130019bbf8e3bd65977f840e8afaf
> Cr-Commit-Position: refs/heads/master@{#39493}
TBR=adamk@chromium.org,caitp@igalia.com,hablich@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
BUG=v8:5390
Review-Url: https://codereview.chromium.org/2348403002
Cr-Commit-Position: refs/heads/master@{#39508}
Reason for revert:
newly introduced test async-await-loop times out: https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/10894/steps/Ignition%20-%20turbofan%20%28flakes%29/logs/async-await-loop
Original issue's description:
> Fix async/await memory leak
>
> This patch closes a memory leak in async/await where the desugaring
> was creating a situation analagous to that described in v8:5002.
> Intermediate Promises were being kept alive, so a long-running loop
> would cause linear memory usage on the heap. This patch returns
> undefined to the 'then' callback passed into PerformPromiseThen
> in order to avoid this hazard. Test expectations are fixed to remove
> expecting extraneous events which occurred on Promises that are
> now not given unnecessarily complex resolution paths before being
> thrown away.
>
> BUG=v8:5390
>
> Committed: https://crrev.com/a0ba18e9634c5e2d439033ab61a77cff54f9af35
> Cr-Commit-Position: refs/heads/master@{#39479}
TBR=adamk@chromium.org,caitp@igalia.com,littledan@chromium.org
NOTRY=true
BUG=v8:5390
Review-Url: https://codereview.chromium.org/2354473002
Cr-Commit-Position: refs/heads/master@{#39493}
This patch closes a memory leak in async/await where the desugaring
was creating a situation analagous to that described in v8:5002.
Intermediate Promises were being kept alive, so a long-running loop
would cause linear memory usage on the heap. This patch returns
undefined to the 'then' callback passed into PerformPromiseThen
in order to avoid this hazard. Test expectations are fixed to remove
expecting extraneous events which occurred on Promises that are
now not given unnecessarily complex resolution paths before being
thrown away.
BUG=v8:5390
Review-Url: https://codereview.chromium.org/2334323006
Cr-Commit-Position: refs/heads/master@{#39479}
Handle the "synchronous case" by marking try/catch blocks introduced for
async functions as ASYNC_AWAIT and traversing up the stack, finding successive
Promises and returning caught if any of them are predicted to be caught.
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2325813002
Cr-Commit-Position: refs/heads/master@{#39433}
To make async/await catch prediction work well, this patch regularizes
the exception events sent to DevTools from various places in the Promise
lifecycle. The core is that there should be an exception event when the
rejection first starts, rather than when it is propagated.
- Several cases within Promise code which propagate errors are
modified to not trigger a new ExceptionEvent in that case, such
as .then on a rejected Promise and returning a rejected Promise
from .then, as well as Promise.race and Promise.all.
- Make Promise.reject() create an ExceptionEvent, subject to catch
prediction based on the Promise stack. This is important
so that, e.g., if "await Promise.reject()" will trigger a new
throw (rather than a silent rethrow of something that never
triggered an event in the first place).
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2244003003
Cr-Commit-Position: refs/heads/master@{#38847}
Reason for revert:
WebGL tests have been updated and rolled (at https://codereview.chromium.org/2227023002), so this should no longer fail outdated tests.
Original issue's description:
> Revert of Amend DataView, ArrayBuffer, and TypedArray methods to use ToIndex. (patchset #8 id:140001 of https://codereview.chromium.org/2090353003/ )
>
> Reason for revert:
> Speculative revert to unblock roll: https://codereview.chromium.org/2107223003/
>
> Original issue's description:
> > Amend DataView, ArrayBuffer, and TypedArray methods to use ToIndex.
> >
> > The spec was modified to relax some requirements which implementors had not been
> > enforcing. Part of this process involved introducing a new abstract operation
> > ToIndex, which had partial overlap with our existing semantics as well as some
> > differences (most notably treating undefined as 0). Test262 tests were introduced to
> > check for the new semantics, some of which we were failing. This patch amends the
> > parts of our implementation corresponding to specification algorithms which use
> > ToIndex to follow its semantics precisely.
> >
> > BUG=v8:4784,v8:5120
> >
> > Committed: https://crrev.com/09720349ea058d178521ec58d0a5676443a5a132
> > Cr-Commit-Position: refs/heads/master@{#37406}
>
> TBR=littledan@chromium.org,adamk@chromium.org,bakkot@google.com
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:4784,v8:5120
>
> Committed: https://crrev.com/b1f7f1f4e41a723d5f997738a07e35a031713b8f
> Cr-Commit-Position: refs/heads/master@{#37417}
TBR=littledan@chromium.org,adamk@chromium.org,hablich@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:4784,v8:5120
Review-Url: https://codereview.chromium.org/2247073004
Cr-Commit-Position: refs/heads/master@{#38689}
Async functions are implemented via special generator functions; special in the
sense that they generally do not immediately yield. However, our generators
implementation still assumed that every generator function initially yields
(concretely: before doing the state dispatch in a loop header). This CL fixes
that.
R=littledan@chromium.org, rmcilroy@chromium.org
BUG=chromium:638019
Review-Url: https://codereview.chromium.org/2253033002
Cr-Commit-Position: refs/heads/master@{#38684}
This patch adds additional tests for async functions and generators, in how
they interact with destructuring, default arguments and shadow parameter
copying.
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2229243002
Cr-Commit-Position: refs/heads/master@{#38560}
Introduces a new VariableLocation MODULE for variables that live in a
module's export table. Scope analysis sets this for the approriate variables.
Not yet supported by any backend.
Also, treats all imports as CONST bindings (including namespace imports), rather
than having new special variable modes.
BUG=
Review-Url: https://codereview.chromium.org/2199283002
Cr-Commit-Position: refs/heads/master@{#38426}
- Don't read .constructor when returning a Promise from an async function.
Instead, call out to the internals of Promise.resolve directly.
This is done by adding back in an "optimization" from an earlier form of
the async/await code written by Caitlin Potter.
- Async functions always return a new Promise with a distinct identity,
even if they simply return another Promise.
R=caitp@igalia.com
BUG=v8:4483
Review-Url: https://codereview.chromium.org/2219623002
Cr-Commit-Position: refs/heads/master@{#38404}
See discussion in https://codereview.chromium.org/2156303002/#msg8
With the new --harmony-function-tostring behavior, these tests would
fail without this change. This change makes the tests pass regardless
of whether or not --harmony-function-tostring is used.
All of these changes are simply inserting a space after the "function"
keyword to match the current function toString behavior. When
--harmony-function-tostring is enabled, the toString behavior matches
the spacing used in the function declaration. With the declaration
matching the current formatting, the toString behavior becomes
unaffected by --harmony-function-tostring.
BUG=v8:4958
LOG=n
Review-Url: https://codereview.chromium.org/2161413002
Cr-Commit-Position: refs/heads/master@{#37959}
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}
* 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}
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}
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}
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}
Reason for revert:
Speculative revert to unblock roll: https://codereview.chromium.org/2107223003/
Original issue's description:
> Amend DataView, ArrayBuffer, and TypedArray methods to use ToIndex.
>
> The spec was modified to relax some requirements which implementors had not been
> enforcing. Part of this process involved introducing a new abstract operation
> ToIndex, which had partial overlap with our existing semantics as well as some
> differences (most notably treating undefined as 0). Test262 tests were introduced to
> check for the new semantics, some of which we were failing. This patch amends the
> parts of our implementation corresponding to specification algorithms which use
> ToIndex to follow its semantics precisely.
>
> BUG=v8:4784,v8:5120
>
> Committed: https://crrev.com/09720349ea058d178521ec58d0a5676443a5a132
> Cr-Commit-Position: refs/heads/master@{#37406}
TBR=littledan@chromium.org,adamk@chromium.org,bakkot@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4784,v8:5120
Review-Url: https://codereview.chromium.org/2113593002
Cr-Commit-Position: refs/heads/master@{#37417}
The spec was modified to relax some requirements which implementors had not been
enforcing. Part of this process involved introducing a new abstract operation
ToIndex, which had partial overlap with our existing semantics as well as some
differences (most notably treating undefined as 0). Test262 tests were introduced to
check for the new semantics, some of which we were failing. This patch amends the
parts of our implementation corresponding to specification algorithms which use
ToIndex to follow its semantics precisely.
BUG=v8:4784,v8:5120
Review-Url: https://codereview.chromium.org/2090353003
Cr-Commit-Position: refs/heads/master@{#37406}
Add a flag harmony_trailing_commas_in_parameters that allows trailing
commas in function parameter declaration lists and function call
parameter lists. Trailing commas are allowed in parenthetical lists like
`(a, b, c,)` only if the next token is `=>`, thereby making it an arrow
function declaration. Only 1 trailing comma is allowed, not `(a,,)`. A
trailing comma must follow a non-rest parameter, so `(,)` and `(...a,)`
are still SyntaxErrors. However, a trailing comma is allowed after a
spread parameter, e.g. `a(...b,);`.
Add parser tests for all of the above.
BUG=v8:5051
LOG=y
Review-Url: https://codereview.chromium.org/2094463002
Cr-Commit-Position: refs/heads/master@{#37355}
When calling the throw method on a generator suspended inside a yield*, yield*
in turn tries to call throw on its iterable. If the iterable does not provide a
throw method, yield* must try to call the return method instead and then throw a
TypeError. Due to a bug in our desugaring, we never threw the TypeError.
R=adamk@chromium.org
BUG=v8:5132
Review-Url: https://codereview.chromium.org/2094253002
Cr-Commit-Position: refs/heads/master@{#37314}
When calling the return method on a generator suspended inside a yield*, yield*
in turn calls return on its iterable. If this results in a "done" iterator,
yield* must return immediately, thus terminating the generator. For some
reason, we didn't terminate the generator but continued right after the yield*.
R=adamk@chromium.org
BUG=v8:5131
Review-Url: https://codereview.chromium.org/2100093002
Cr-Commit-Position: refs/heads/master@{#37310}
Named capture groups may be specified using the /(?<name>pattern)/u
syntax, with named backreferences specified as /\k<name>/u. They're
hidden behind the --harmony-regexp-named-captures flag, and are only
enabled for unicode regexps.
R=yangguo@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2050343002
Cr-Commit-Position: refs/heads/master@{#36986}
This patch adds a test for async/await analogous to a previous Promise test.
It also fixes a typo in promise.js and makes a previous Promise test more
correct by ensuring that all assertions run before completion, fixing the
test expectations for the real result (which seems correct).
BUG=v8:4483
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review-Url: https://codereview.chromium.org/2037653002
Cr-Commit-Position: refs/heads/master@{#36903}
