Commit Graph

354 Commits

Author SHA1 Message Date
Benedikt Meurer
5ee1b7ad5a [turbofan] Add IC support for Call/ConstructWithSpread.
Properly hook up the (existing) IC slots for the CallWithSpread and
ConstructWithSpread bytecodes, and change the interpreter to collect
feedback (call counts and regular target function feedback) for those.
There's no integration with the Array constructor yet, since that
requires some yak shaving to thread through the AllocationSite to the
Array constructor stub. Once we have a solution for that, we can also
remove the current code duplication in the Call/Construct IC logic.

Also properly hook up the newly available feedback in TurboFan. This
will fix not only the missing target feedback, but more importantly
the tear-up decisions for optimization are correct now in the presence
of spread calls, and even more importantly the inlining heurstic has
proper call frequencies for those.

Some follow-up changes will be necessary to make sure we use the
feedback even for corner cases that aren't handled properly yet. Also
we should consider collecting feedback about the map of the spread
at some point to be able to always inline the spread calls.

Bug: v8:6399, v8:6527, v8:6630
Change-Id: I818dbcb411fd3951d8e9d31f5d7e794f8d60fa00
Reviewed-on: https://chromium-review.googlesource.com/582647
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46832}
2017-07-24 07:11:50 +00:00
Caitlin Potter
00681326a3 [interpreter] refactor BuildGeneratorSuspend/Resume into BuildSuspendPoint
Simplify the model for generating Awaits, because the resume point is
always immediately following the suspend point, and registers used are
always the same for both operations.

Includes a minor refactoring of BytecodeGenerator::VisitYield() to
perform iterator result creation before the SuspendGenerator bytecode,
rather than between SuspendGenerator and Return. This adds a small
number of bytecodes for each yield.

BUG=v8:2355, v8:5855

Change-Id: I4868b89a6bc1b251f887d2a45890c8fa19f7b089
Reviewed-on: https://chromium-review.googlesource.com/576286
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#46820}
2017-07-21 16:48:57 +00:00
Alexey Kozyatinskiy
a8176a530c [ignition] removed nop bytecode
Nop bytecodes are required only for break locations in debugger. Since nop bytecode doesn't change program state we can remove all of them.

There are at least two changes which this CL produce:
- we don't provide break position when we load local variable (still provide when load variable from global),
- we don't provide break position for statements without actual break positions (e.g. "a;") - these expressions should be super rare and user always can set breakpoint before or after this statement.

More details in one pager: https://docs.google.com/a/google.com/document/d/1JXlQpfMa9vRojbE272b6GMBbrfh6m_00135iAUOJEz8/edit?usp=sharing

Bug: v8:6425
Change-Id: I4aee73d497a84f7b5d89caa6dda6d3060567dfda
Reviewed-on: https://chromium-review.googlesource.com/543161
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46742}
2017-07-18 16:14:29 +00:00
Ross McIlroy
7bcec7ae79 [Interpreter] Fix expression position on keyed property loads.
BUG=v8:6609

Change-Id: If4c3520fba0653e23e6d34bf344fb00cdbfc6082
Reviewed-on: https://chromium-review.googlesource.com/575049
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46741}
2017-07-18 15:32:29 +00:00
Leszek Swirski
14c5c4fde7 Revert "[runtime] Move profiler ticks from SFI to feedback vector"
This reverts commit a2fcdc7cc8.

Reason for revert: Large regressions in RCS (https://chromeperf.appspot.com/group_report?bug_id=740126)

Original change's description:
> [runtime] Move profiler ticks from SFI to feedback vector
> 
> Instead of counting profiler ticks on the shared function info (which is
> shared between native contexts), count them on the feedback vector
> (which is not). This allows us to continue pushing optimization
> decisions off the SFI, onto the feedback vector.
> 
> Note that a side-effect of this is that ICs don't have to walk the stack
> to reset profiler ticks, as they can access the feedback vector directly
> from their feedback nexus.
> 
> Change-Id: I232ae9e759fca75cd89d393148a4ff42caa2646f
> Reviewed-on: https://chromium-review.googlesource.com/544888
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46411}

TBR=rmcilroy@chromium.org,leszeks@chromium.org,ishell@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Id587e4172e300c420f93c49744a2a0e66696edf8
Reviewed-on: https://chromium-review.googlesource.com/574227
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46702}
2017-07-17 11:51:32 +00:00
Alexey Kozyatinskiy
0896586083 [inspector] improve return position of explicit return in non-async function
Goal of this CL: explicit return from non-async function has position after
return expression as return position (will unblock [1]).

BytecodeArrayBuilder has SetStatementPosition and SetExpressionPosition methods.
If one of these methods is called then next generated bytecode will get passed
position. It's general treatment for most cases.
Unfortunately it doesn't work for Returns:
- debugger requires source positions exactly on kReturn bytecode in stepping
  implementation,
- BytecodeGenerator::BuildReturn and BytecodeGenerator::BuildAsyncReturn
  generates more then one bytecode and general solution will put return position
  on first generated bytecode,
- it's not easy to split BuildReturn function into two parts to allow something
  like following in BytecodeGenerator::VisitReturnStatement since generated
  bytecodes are actually controlled by execution_control().
..->BuildReturnPrologue();
..->SetReturnPosition(stmt);
..->Return();

In this CL we pass ReturnStatement through ExecutionControl and use it for
position when we emit return bytecode right here.

So this CL only will improve return position for returns inside of non-async
functions, I'll address async functions later.

[1] https://chromium-review.googlesource.com/c/543161/

Change-Id: Iede512c120b00c209990bf50c20e7d23dc0d65db
Reviewed-on: https://chromium-review.googlesource.com/560738
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46687}
2017-07-14 19:10:13 +00:00
Caitlin Potter
53553f5dcb [generators] remove SuspendFlags enum and related code
SuspendFlags was originally used by the suspend operation to determine
which field to record the bytecode offset of a suspended generator, and
the value the generator was resumed with. For async generators, await
operations would use a separate field, in order to preserve the previous
yield input value. This was important to ensure `function.sent`
continued to function correctly.

As function.sent is being retired, this allows the removal of support
for that. Given that this was the only real need for SuspendFlags in the
first place (with other uses tacked on as a hack), this involves several
other changes as well:

- Modification of MacroAssembler AssertGeneratorObject. No longer
  accepts a SuspendFlags parameter to determine which type of check to
  perform.
- Removal of `flags` operand from SuspendGenerator bytecode, and the
  GeneratorStore js-operator.
- Removal of `flags` parameter from ResumeGeneratorTrampoline builtins.
- Removal of Runtime functions, interpreter intrinsics and
  AccessBuilders associated with the [[await_input_or_debug_pos]] field
  in JSAsyncGeneratorObject, as this field no longer exists.
- Addition of a new `Yield` AST node (subclass of Suspend) in order to
  prevent the need for the other SuspendFlag values.

BUG=v8:5855
TBR=bmeurer@chromium.org

Change-Id: Iff2881e4742497fe5b774915e988c3d9d8fbe487
Reviewed-on: https://chromium-review.googlesource.com/570485
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46683}
2017-07-14 16:09:53 +00:00
Caitlin Potter
8b5b444a4c [async-await] desugar Await in BytecodeGenerator
This includes several changes. From most to least interesting:

- No longer implement AwaitExpressions using a do-expression.
- Reduces frame-size of async generators by not allocating temporary
  variables to hold results of Await epxressions.
- Streamline and reduce generated bytecodes for Await.
- Debugger no longer emits a debug::kCallBreakLocation breakpoint for
the JS-builtin call performed for Await, and instead only emits such
a breakpoint if the operand of Await is actually a call.
- Push fewer parameters to Await* builtins, using the receiver for the
  first parameter (possible now that the CallRuntime invocation not
  part of the AST).
- Adds a new Await AST node. No new members or anything, but it seemed
  palatable to avoid having `if (is_await())` in a number of
  VisitSuspend functions.

BUG=v8:5855, v8:5099, v8:4483
R=rmcilroy@chromium.org, kozyatinskiy@chromium.org, yangguo@chromium.org
TBR=bmeurer@chromium.org

Change-Id: I9cd3fda99cd40295c04fdf1aea01b5d83fac6caf
Reviewed-on: https://chromium-review.googlesource.com/558806
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46666}
2017-07-14 08:57:51 +00:00
Ross McIlroy
aa69a48f78 Disable StringConcat bytecode.
Didn't seem to help and caused a couple of regressions.

BUG=v8:6243,chromium:740124

Change-Id: I72887ba245a524211dbf181c77d0cdc6d917d090
Reviewed-on: https://chromium-review.googlesource.com/568480
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46608}
2017-07-12 21:51:20 +00:00
Camillo Bruni
36421dc467 [literals] Disable double lazy boilerplate for literals containing Arrays
By creating the boilerplate only on the second instantiation we cannot
propagate back the elements transitions early enough. The resulting literals
would change the initial ElementsKind one step too late and already pollute
ICs that went to monomorphic state.

- Disable lazy AllocationSites for literals containing arrays
- Introduce new ComplexLiteral class to share code between ObjectLiteral
  and ArrayLiteral
- RegexpLiteral now no longer needs a depth_ field

Bug: v8:6517, v8:6519, v8:6211
Change-Id: Ia88d1878954e8895c3d00a7dda8d71e95bba005c
Reviewed-on: https://chromium-review.googlesource.com/563305
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46603}
2017-07-12 19:11:04 +00:00
Alexey Kozyatinskiy
61ea32436d Reland "[parser] moved load property position after dot"
This is a reland of 5b44ba0e34
Original change's description:
> (Reland) [parser] moved load property position after dot
> 
> Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
> It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.
> 
> R=jgruber@chromium.org
> TBR=marja@chromium.org
> 
> Bug: v8:6425
> Change-Id: I05c21ca5e018da9c432c6bc963c7a96799336d1c
> Reviewed-on: https://chromium-review.googlesource.com/562879
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46484}

TBR=marja@chromium.org,jgruber@chromium.org
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng

Bug: v8:6425
Change-Id: I5eba5fe43ad31c5c781ffcc8c604cd9c98baa57e
Reviewed-on: https://chromium-review.googlesource.com/565907
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46542}
2017-07-10 22:17:58 +00:00
Caitlin Potter
10b9c019ce [parser] avoid for-loop desugaring unless loop var may be captured
In https://chromium-review.googlesource.com/c/472247/, I avoided
running DesugarLexicalBindingsInForStatement() if there were no lexical
loop variables, the function was not resumable, and the variables are
not captured by eval or a function declaration.

I think it's now possible to limit this further, and only do the more
extensive desugaring if there's a function declaration / eval() call
in the loop body. `yield` and `await` are not an issue as those loop
variables are written to the register file and not lost.

This change just removes the `is_resumable()` condition. If it passes
tests, I think it's safe.

BUG=v8:4762, v8:5460, v8:6579

Change-Id: I92d0308ad9401c1338411bc9ae9021f978803d3a
Reviewed-on: https://chromium-review.googlesource.com/563587
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46536}
2017-07-10 18:06:18 +00:00
Igor Sheludko
fa41e3b218 [runtime] Create only one instance of %ThrowTypeError%.
... according to the spec ES#sec-%throwtypeerror%

Bug: v8:4034
Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: Ia4f2d228397edf55447fe3e71402c8fc4589369a
Reviewed-on: https://chromium-review.googlesource.com/563214
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46498}
2017-07-10 08:26:02 +00:00
Michael Achenbach
ed8df4dd4c Revert "(Reland) [parser] moved load property position after dot"
This reverts commit 5b44ba0e34.

Reason for revert: Layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/16841

Original change's description:
> (Reland) [parser] moved load property position after dot
> 
> Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
> It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.
> 
> R=​jgruber@chromium.org
> TBR=marja@chromium.org
> 
> Bug: v8:6425
> Change-Id: I05c21ca5e018da9c432c6bc963c7a96799336d1c
> Reviewed-on: https://chromium-review.googlesource.com/562879
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46484}

TBR=kozyatinskiy@chromium.org,jgruber@chromium.org

Change-Id: If9d5fa5f46ed10a407559e9cf10d2a6a54dbe163
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6425
Reviewed-on: https://chromium-review.googlesource.com/564418
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46491}
2017-07-08 11:37:12 +00:00
Alexey Kozyatinskiy
5b44ba0e34 (Reland) [parser] moved load property position after dot
Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.

R=jgruber@chromium.org
TBR=marja@chromium.org

Bug: v8:6425
Change-Id: I05c21ca5e018da9c432c6bc963c7a96799336d1c
Reviewed-on: https://chromium-review.googlesource.com/562879
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46484}
2017-07-07 14:57:10 +00:00
Ross McIlroy
d425306d53 Reland: Enable StringConcat bytecode.
BUG=v8:6243
TBR=jgruber@chromium.org,leszeks@chromium.org

Change-Id: Ib830681073f4d3de4e500bf6144c0df2f9f4873f
Reviewed-on: https://chromium-review.googlesource.com/562775
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46469}
2017-07-07 10:19:39 +00:00
Sathya Gunasekaran
d8e1c4840c [parser] Improve error message for destructuring non iterable
Print the object that is being destructured and update the error 
message.

Previously,
  d8> var [a] = {}
  (d8):1: TypeError: [Symbol.iterator] is not a function

Now,
  d8> var [a] = {}
  (d8):1: TypeError: {} is not iterable

Bug: v8:6513, v8:5532
Change-Id: I5cbfe7c7e20632bce1a48bd38a1b0c98d0ff0660
Reviewed-on: https://chromium-review.googlesource.com/557370
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#46457}
2017-07-06 19:57:44 +00:00
Leszek Swirski
a2fcdc7cc8 [runtime] Move profiler ticks from SFI to feedback vector
Instead of counting profiler ticks on the shared function info (which is
shared between native contexts), count them on the feedback vector
(which is not). This allows us to continue pushing optimization
decisions off the SFI, onto the feedback vector.

Note that a side-effect of this is that ICs don't have to walk the stack
to reset profiler ticks, as they can access the feedback vector directly
from their feedback nexus.

Change-Id: I232ae9e759fca75cd89d393148a4ff42caa2646f
Reviewed-on: https://chromium-review.googlesource.com/544888
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46411}
2017-07-05 12:04:50 +00:00
Caitlin Potter
7cf7a4307b [cctest] add Async Generator bytecode tests
These were originally written as part of
https://chromium-review.googlesource.com/c/550396/. I've separated them
out into a separate CL with the intent of landing it first, so that it's
easier to see the difference these CLs will have on generated bytecode.

BUG=v8:5855
TBR=tebbi@chromium.org, rmcilroy@chromium.org

Change-Id: Ib84e65847d7396e31b0e38d28f59454cf7c58fc1
Reviewed-on: https://chromium-review.googlesource.com/558221
Reviewed-by: Caitlin Potter <caitp@igalia.com>
Commit-Queue: Caitlin Potter <caitp@igalia.com>
Cr-Commit-Position: refs/heads/master@{#46370}
2017-07-02 21:34:50 +00:00
Leszek Swirski
2b1eb978c1 [parsing/runtime] Remove InitializeVarGlobal
Change-Id: I2ee0ff9db1bbc8c17a1ad3dea1de1ad996895852
Reviewed-on: https://chromium-review.googlesource.com/474807
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46338}
2017-06-30 08:03:04 +00:00
Michael Achenbach
2ac6dae6fa Revert "Enable StringConcat bytecode."
This reverts commit 189c8263e5.

Reason for revert: Lots of layout test changes:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/16607

Original change's description:
> Enable StringConcat bytecode.
> 
> BUG=v8:6243
> 
> Change-Id: Idb9aa8221248cc493c8f5ba4bd50fa712a57f5f8
> Reviewed-on: https://chromium-review.googlesource.com/541221
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46249}

TBR=rmcilroy@chromium.org,jgruber@chromium.org,leszeks@chromium.org

Change-Id: I3ce96264d8c0e183b02c0344b90275e207683f7a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6243
Reviewed-on: https://chromium-review.googlesource.com/550157
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46261}
2017-06-27 15:10:07 +00:00
Ross McIlroy
189c8263e5 Enable StringConcat bytecode.
BUG=v8:6243

Change-Id: Idb9aa8221248cc493c8f5ba4bd50fa712a57f5f8
Reviewed-on: https://chromium-review.googlesource.com/541221
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46249}
2017-06-27 12:23:15 +00:00
Leszek Swirski
c6414dacdd Revert "[ignition] Merge bytecode array builder and writer"
This reverts commit 87f71769c5.

Reason for revert: Performance regressions https://chromeperf.appspot.com/group_report?rev=46185

Original change's description:
> [ignition] Merge bytecode array builder and writer
> 
> Move bytecode array writing logic into the array builder, allowing us to
> remove the bytecode array writer and bytecode node, and convert runtime
> operand writing to compile-time bytecode operand writing using the
> information statically known at compile time.
> 
> Bug: v8:6474
> Change-Id: I210cd9897fd41293745614e4a253c7c251dfffc9
> Reviewed-on: https://chromium-review.googlesource.com/533055
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46183}

TBR=rmcilroy@chromium.org,leszeks@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:6474
Bug: chromium:736646
Change-Id: I00287b2bbbb8efa5a3141bc9c2906f91a7d33e51
Reviewed-on: https://chromium-review.googlesource.com/549319
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46235}
2017-06-27 09:10:18 +00:00
Leszek Swirski
87f71769c5 [ignition] Merge bytecode array builder and writer
Move bytecode array writing logic into the array builder, allowing us to
remove the bytecode array writer and bytecode node, and convert runtime
operand writing to compile-time bytecode operand writing using the
information statically known at compile time.

Bug: v8:6474
Change-Id: I210cd9897fd41293745614e4a253c7c251dfffc9
Reviewed-on: https://chromium-review.googlesource.com/533055
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46183}
2017-06-23 14:52:20 +00:00
Michael Achenbach
4441809338 Revert "[parser] moved load property position after dot"
This reverts commit 217d654c9b.

Reason for revert: Changes layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/16520

Original change's description:
> [parser] moved load property position after dot
> 
> Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
> It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.
> 
> R=​jgruber@chromium.org
> 
> Bug: v8:6425
> Change-Id: I528c5007de52215beba80851ab04693ecec038e2
> Reviewed-on: https://chromium-review.googlesource.com/543047
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#46163}

TBR=marja@chromium.org,kozyatinskiy@chromium.org,jgruber@chromium.org

Change-Id: I94543526f39f0a20452fbce1a7bc6744cac66621
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6425
Reviewed-on: https://chromium-review.googlesource.com/544993
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46171}
2017-06-23 12:46:57 +00:00
Tobias Tebbi
31b88650be [ignition] desugar yield* in the BytecodeGenerator
Async generator yield* is still desugared in the parser, to be moved to the BytecodeGenerator in a future CL.

Bug: v8:6472
Change-Id: I8b33e2f9e931949f7375540099cd8ec3a6b27cf1
Reviewed-on: https://chromium-review.googlesource.com/539335
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46165}
2017-06-23 11:14:40 +00:00
Alexey Kozyatinskiy
217d654c9b [parser] moved load property position after dot
Currently LdaNamedProperty bytecode for expressions like a.b has position before dot. This CL moves this location after dot.
It's important for later removing of Nop bytecodes in expressions like a.b() where a is local variable, property call and property load should have the same position.

R=jgruber@chromium.org

Bug: v8:6425
Change-Id: I528c5007de52215beba80851ab04693ecec038e2
Reviewed-on: https://chromium-review.googlesource.com/543047
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46163}
2017-06-23 11:05:49 +00:00
Daniel Ehrenberg
d54ffadfda [scopes] Fix sloppy-mode block-scoped function hoisting edge case
In edge cases such as the following, sloppy-mode block-scoped function
hoisting is expected to occur:

  eval(`
    with({a: 1}) {
      function a() {}
    }
  `)

In this case, there should be the equivalent of a var declaration
outside of the eval, which gets set to the value of the local function
a when the body of the with is executed.

Previously, the way that var declarations are hoisted out of eval
meant that the assignment to that var was an ordinary DYNAMIC_GLOBAL
assignment. However, such a lookup mode meant that the object in the
with scope received the assignment!

This patch fixes that error by marking the assignments produced by
the sloppy mode block scoped function hoisting desugaring so as to
generate a different runtime call which skips with scopes.

Bug: chromium:720247, v8:5135
Change-Id: Ie36322ddc9ca848bf680163e8c016f50d4597748
Reviewed-on: https://chromium-review.googlesource.com/529230
Commit-Queue: Daniel Ehrenberg <littledan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46116}
2017-06-22 08:18:55 +00:00
Leszek Swirski
24b7026d73 [compiler] Drive optimizations with feedback vector (reland)
For interpreted functions, use the optimized code slot in the feedback
vector to store an optimization marker (optimize/in optimization queue)
rather than changing the JSFunction's code object. Then, adapt the
self-healing mechanism to also dispatch based on this optimization
marker. Similarly, replace SFI marking with optimization marker checks
in CompileLazy.

This allows JSFunctions to share optimization information (replacing
shared function marking) without leaking this information across native
contexts. Non I+TF functions (asm.js or --no-turbo) use a
CheckOptimizationMarker shim which generalises the old
CompileOptimized/InOptimizationQueue builtins and also checks the same
optimization marker as CompileLazy and InterpreterEntryTrampoline.

This is a reland of https://chromium-review.googlesource.com/c/509716

Change-Id: I02b790544596562373da4c9c9f6afde5fb3bcffe
Reviewed-on: https://chromium-review.googlesource.com/535460
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45997}
2017-06-19 10:33:59 +00:00
Camillo Bruni
015edc60ff [runtime] Don't store object literal boilerplates on first run
Storing the boilerplate on the first run leads to memory ovehead for code
that is run only once. Hence we directly return the creating literal on the
first run and only start creating copies from the second run on.

Bug: v8:6211
Change-Id: I69b96d124a5b594b991fdbcc76dbf935d973ffad
Reviewed-on: https://chromium-review.googlesource.com/530688
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45975}
2017-06-16 10:43:19 +00:00
Sathya Gunasekaran
bc2c785c20 [parser] Better error message when destructuring against undefined/null
Previously, when destructuring against null or undefined we would
print:

  d8> var { x } = null
  (d8):1: TypeError: Cannot match against 'undefined' or 'null'.
  var { x } = null
  ^
  TypeError: Cannot match against 'undefined' or 'null'.
      at (d8):1:1


The above message uses the term "match" which isn't a common term in
JavaScript to describe destructuring. This message also doesn't
provide the name of the property that fails destructuring.

This patch changes the error message to be:

  d8> var { x } = null;
  (d8):1: TypeError: Cannot destructure property `x` of 'undefined' or 'null'.
  var { x } = null;
        ^
  TypeError: Cannot destructure property `x` of 'undefined' or 'null'.
      at (d8):1:1

This patch changes the message to say "destructure" instead of "match".

This patch adds support for printing property names that are string
literals. We iterate through every property and pick the first string
literal property name if it exists. This provides at least some
feedback to the developer.

This patch also makes the pointer point to the position of the
property name that fails destructuring.

For computed and numeric property names, we print a generic error:
  d8> var { 1: x } = null
  (d8):1: TypeError: Cannot destructure against 'undefined' or 'null'.
  var { 1: x } = null
  ^
  TypeError: Cannot destructure against 'undefined' or 'null'.
      at (d8):1:1

Bug: v8:6499
Change-Id: I35b1ac749489828686f042975294b9926e2dfc53
Reviewed-on: https://chromium-review.googlesource.com/537341
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45965}
2017-06-15 21:52:58 +00:00
jarin
814d08a6af Move closing of generators upon final return to the generator-resume builtin.
Review-Url: https://codereview.chromium.org/2936813002
Cr-Commit-Position: refs/heads/master@{#45906}
2017-06-13 13:49:45 +00:00
Leszek Swirski
58978da698 Revert "[compiler] Drive optimizations with feedback vector"
This reverts commit e39c9e020f.

Reason for revert: Breaks https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20debug/builds/15561

Original change's description:
> [compiler] Drive optimizations with feedback vector
> 
> For interpreted functions, use the optimized code slot in the feedback vector
> to store an optimization marker (optimize/in optimization queue) rather than
> changing the JSFunction's code object. Then, adapt the self-healing mechanism
> to also dispatch based on this optimization marker. Similarly, replace SFI
> marking with optimization marker checks in CompileLazy.
> 
> This allows JSFunctions to share optimization information (replacing shared
> function marking) without leaking this information across native contexts. Non
> I+TF functions (asm.js or --no-turbo) use a CheckOptimizationMarker shim which
> generalises the old CompileOptimized/InOptimizationQueue builtins and also
> checks the same optimization marker as CompileLazy and
> InterpreterEntryTrampoline.
> 
> Change-Id: I6826bdde7ab9a919cdb6b69bc0ebc6174bcb91ae
> Reviewed-on: https://chromium-review.googlesource.com/509716
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45901}

TBR=rmcilroy@chromium.org,mstarzinger@chromium.org,leszeks@chromium.org
No-Presubmit: true
No-Tree-Checks: true
No-Try: true

Change-Id: Ib6c2b4d90fc5f659a6dcaf3fd30321507ca9cb94
Reviewed-on: https://chromium-review.googlesource.com/532916
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45903}
2017-06-13 13:24:20 +00:00
Leszek Swirski
e39c9e020f [compiler] Drive optimizations with feedback vector
For interpreted functions, use the optimized code slot in the feedback vector
to store an optimization marker (optimize/in optimization queue) rather than
changing the JSFunction's code object. Then, adapt the self-healing mechanism
to also dispatch based on this optimization marker. Similarly, replace SFI
marking with optimization marker checks in CompileLazy.

This allows JSFunctions to share optimization information (replacing shared
function marking) without leaking this information across native contexts. Non
I+TF functions (asm.js or --no-turbo) use a CheckOptimizationMarker shim which
generalises the old CompileOptimized/InOptimizationQueue builtins and also
checks the same optimization marker as CompileLazy and
InterpreterEntryTrampoline.

Change-Id: I6826bdde7ab9a919cdb6b69bc0ebc6174bcb91ae
Reviewed-on: https://chromium-review.googlesource.com/509716
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45901}
2017-06-13 12:27:40 +00:00
Alexandre Talon
8edef78d4d [ignition] Fix register flushing performance issue
In some codes flushing the registers was costly: we processed each
register whereas all the registers alone in their equivalence class need
not to be processed. We now overapproximate easily which classes are of
size 2 so as to save many iterations in the Flush() loop in some cases.

Bug: v8:6432
Change-Id: I945e151736e8a515263ac76312127d930fd20d74
Reviewed-on: https://chromium-review.googlesource.com/525795
Commit-Queue: Alexandre Talon <alexandret@google.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45805}
2017-06-09 09:58:15 +00:00
jarin
b543c2daba [interpreter] Make sure allocated registers are always materialized in the register optimizer.
BUG=chromium:729369

Review-Url: https://codereview.chromium.org/2926063002
Cr-Commit-Position: refs/heads/master@{#45770}
2017-06-07 15:39:56 +00:00
Mythri
c360c6a1d0 [Interpreter] Introduce bytecodes that check for hole and throw.
Introduces ThrowReferenceErrorIfHole / ThrowSuperNotCalledIfHole 
/ ThrowSuperAlreadyCalledIfNotHole bytecodes to handle hole checks.
In the bytecode-graph builder they are handled by introducing a deopt point
instead of adding explicit control flow. JumpIfNotHole / JumpIfNotHoleConstant
bytecodes are removed since they are no longer required.


Bug: v8:4280, v8:6383
Change-Id: I58b70c556b0ffa30e41a0cd44016874c3e9c5fe1
Reviewed-on: https://chromium-review.googlesource.com/509613
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45720}
2017-06-06 09:41:31 +00:00
jarin
7fa77063cf Move generator-close on exception from the generator function to the GeneratorResume builtin.
The change also moves creation of the iterator result from the parser to the bytecode generator.

Unfortunately, async generators will stay on the old scheme (try-finally around generator body) because I am not exactly sure how they work.

Review-Url: https://codereview.chromium.org/2917263002
Cr-Commit-Position: refs/heads/master@{#45713}
2017-06-05 19:54:14 +00:00
Adam Klein
b58439238b [generators] Remove generator_object_ member from Suspend AST node
Now that the BytecodeGenerator has a dedicated register holding
the generator object, BytecodeGenerator::VisitSuspend can
access the generator directly from that register. This reduces
by one the number of live registers at each suspend point.

Bug: v8:6351, v8:6460
Change-Id: I380a9d2bd8ca7eec6720e5392c1ca07dd0df0e2d
Reviewed-on: https://chromium-review.googlesource.com/522982
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45710}
2017-06-05 18:11:02 +00:00
Leszek Swirski
0ef0fc50b1 [ignition] Use jump table for generator resume mode
Bug: v8:6351
Change-Id: Iad82fcfb4172d7a9cbadffa1e40fd1cd26866895
Reviewed-on: https://chromium-review.googlesource.com/521107
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45705}
2017-06-05 13:52:07 +00:00
jarin
f0645612c4 This is a first step towards reducing the number of stores/loads when suspending/resuming a generator.
Unfortunately, even for an empty generator, we still use 8 register for various things (try-finally, copies of generator object, parser-introduced temporaries). I will try to get rid of these in separate CLs.

Changes:

- SuspendGenerator bytecode now takes register list to save.
- ResumeGenerator was split into two bytecodes:
  * Resume generator reads the state out and marks the generator as
      'executing'.
  * RestoreGeneratorRegisters reloads the registers from
      the generator.
    + this required adding support for output register list.

- Introduced generator_object_ register in the bytecode generator.
  * in subsequent CLs, I will make better use of it, the goal is
      to get rid if the .generator_object local variable.

- Taught register optimizer to flush unassigned registers.

BUG=v8:6379

Review-Url: https://codereview.chromium.org/2894293003
Cr-Commit-Position: refs/heads/master@{#45675}
2017-06-02 11:55:48 +00:00
Alexey Kozyatinskiy
6f69e3ceca [inspector] removed break location right before suspension in async function
In current implementation in expressions like await foo() we have break location right after foo call and before actual await.
And we additionally have a lot of other statement locations because of do scope.

Let's move async debugging closer to sync debugging and introduce only one break location for await - before awaited function call.

Bug: v8:6425,v8:6162
Change-Id: I7568767856022c49101e7f3b7e39a2e401d21644
Reviewed-on: https://chromium-review.googlesource.com/514046
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45625}
2017-05-31 12:15:09 +00:00
Aleksey Kozyatinskiy
fb6a094db5 [inspector] moved var initialization break location before init expression (reland)
This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
Benefits (see test for details):
 - only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
 - removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
 
TBR=dgozman@chromium.org,rmcilroy@chromium.org,machenbach@chromium.org,marja@chromium.org,kozyatinskiy@chromium.org,devtools-reviews@chromium.org,v8-reviews@googlegroups.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:5909

Change-Id: Ie84fa79afeed09e28cf8478ba610a0cfbfdfc294
Reviewed-on: https://chromium-review.googlesource.com/518116
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45598}
2017-05-30 12:54:49 +00:00
Camillo Bruni
e822488d76 [runtime] Directly support double values in CloneShallowObjectLiteral
Bug: v8:6211
Change-Id: If6d2ef7889ae6a0c3aa430d3f69c53f19cc1f1c6
Reviewed-on: https://chromium-review.googlesource.com/509571
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45563}
2017-05-29 13:27:17 +00:00
Michael Achenbach
ee1db48cc3 Revert "[inspector] moved var initialization break location before init expression"
This reverts commit 7a9cc70492.

Reason for revert: Changes layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/15882

This is about:
inspector/sources/debugger/source-frame-inline-breakpoint-decorations.html

Original change's description:
> [inspector] moved var initialization break location before init expression
> 
> This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
> Benefits (see test for details):
> - only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
> - removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
> 
> Bug: v8:5909
> Change-Id: I039d911903a2826c9859710a63ab0462c992e11b
> Reviewed-on: https://chromium-review.googlesource.com/513926
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45530}

TBR=dgozman@chromium.org,marja@chromium.org,kozyatinskiy@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:5909

Change-Id: Ibf84401e8050d3c84db219d983de2c6bba0f697f
Reviewed-on: https://chromium-review.googlesource.com/518102
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45547}
2017-05-29 07:03:23 +00:00
Alexey Kozyatinskiy
7a9cc70492 [inspector] moved var initialization break location before init expression
This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
Benefits (see test for details):
- only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
- removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.

Bug: v8:5909
Change-Id: I039d911903a2826c9859710a63ab0462c992e11b
Reviewed-on: https://chromium-review.googlesource.com/513926
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45530}
2017-05-25 14:51:17 +00:00
Ross McIlroy
c68df4110d [Interpreter] Allocate context registers as temporary registers.
Rather than trying to pre-calculate the number of contexts required during
scope analysis, instead just allocate context registers in the register
allocator. This reduces frame size a bit due to reusing of registers when
the context isn't pushed.

 BUG=v8:6322, chromium:716265

Change-Id: I145e38fcb3797a3b86c91e90ea9326a6e55b9b89
Reviewed-on: https://chromium-review.googlesource.com/514087
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45522}
2017-05-24 17:12:02 +00:00
jarin
a957b0f424 Make non-Module generators only context allocate parameters.
In particular, local variables should be allocated on stack (in bytecode register), and stored/loaded to the generator object on generator suspend/resume.

The CL is based on @adamk's change to scoping/parsers (https://chromium-review.googlesource.com/c/498538/), I only made the debugger cope with this change.

I should note that the CL changes the scope type of suspended generators from ScopeType.Closure to ScopeType.Local. In the future we might want to introduce ScopeType.SuspendedGenerator to make the distinction explicit.

Some of the changes in the tests have been made because the debugger functions do not return scopes of closed generators anymore. Generators should be allowed to throw away their internal state when they finish.

BUG=v8:6368

Review-Url: https://codereview.chromium.org/2898163002
Cr-Commit-Position: refs/heads/master@{#45515}
2017-05-24 13:54:57 +00:00
kozyatinskiy
fb78710c06 [inspector] removed call break location from for-of loop
There are two break locations at the same source location by desugaring:
- call iterator.next,
- before variable assignment.

Additionally location for for..of loops is moved from before "of" to before each variable expression.

We should not report first implicit call to avoid user confusion. User still able to go into .next function with both scenarios:
- when this call is reached by stepOver or stepInto from previous line,
- when this call is reached because of breakpoint at current line.

BUG=v8:6425
R=dgozman@chromium.org,jgruber@chromium.org

Review-Url: https://codereview.chromium.org/2893313002
Cr-Commit-Position: refs/heads/master@{#45509}
2017-05-24 12:12:53 +00:00
Michael Starzinger
02fee655b3 [interpreter] Avoid redundant {PopContext} instructions.
This avoids emitting redundant {PopContext} bytecode instructions when
non-local control-flow leaves the method body. It also folds multiple
such {PopContext} instructions into one, in case several scoping levels
are crossed at one. Only the expected context of the target of a local
control-flow transfer matters.

R=rmcilroy@chromium.org
TEST=debugger/regress/regress-crbug-724858
BUG=chromium:724858

Change-Id: Id4a47ae9fea25e75ae1af13619720b16a3975edf
Reviewed-on: https://chromium-review.googlesource.com/512545
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45507}
2017-05-24 11:58:47 +00:00