Commit Graph

7 Commits

Author SHA1 Message Date
Benedikt Meurer
3740764cca [debug][cleanup] Use consistent StepInto and StepOver naming.
In the Chrome DevTools Protocol, the step actions are named StepOut,
StepOver, and StepInto, but internally we used StepOut, StepNext, and
StepIn instead. This change adjusts the naming to be consistent.

Bug: chromium:901814, chromium:1162229
Change-Id: Id3502a1b0a4aadd94734ec3d1fef73c1782fa220
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2928510
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74877}
2021-06-01 11:26:57 +00:00
tzik
07011cc4f0 Replace %RunMicrotasks with %PerformMicrotaskCheckpoint
This replaces Runtime_RunMicrotasks with Runtime_PerformMicrotaskCheckpoint.

RunMicrotasks forcibly runs Microtasks even when the microtasks are suppressed,
and may causes nested Microtasks in a problematic way. E.g. that confuses
v8::MicrotasksScope::IsRunningMicrotasks() and GetEnteredOrMicrotaskContext().

OTOH, PerformMicrotaskCheckpoint() doesn't run cause the failure as it
respects the microtask suppressions.

As all existing tests don't call RunMicrotasks() in the suppressed situation
(like Promise.resolve().then(()=>{%RunMicrotasks();})), this change should
not affect to these tests.

Change-Id: Ib043a0cc8e482e022d375084d65ea98a6f54ef3d
Reviewed-on: https://chromium-review.googlesource.com/c/1360095
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58068}
2018-12-06 11:10:18 +00:00
Benedikt Meurer
0038e5f05f [async] Improve async function handling.
This change introduces new intrinsics used to desugar async functions
in the Parser and the BytecodeGenerator, namely we introduce a new
%_AsyncFunctionEnter intrinsic that constructs the generator object
for the async function (and in the future will also create the outer
promise for the async function). This generator object is internal
and never escapes to user code, plus since async functions don't have
a "prototype" property, we can just a single map here instead of tracking
the prototype/initial_map on every async function. This saves one word
per async function plus one initial_map per async function that was
invoked at least once.

We also introduce two new intrinsics %_AsyncFunctionReject, which
rejects the outer promise with the caught exception, and another
%_AsyncFunctionResolve, which resolves the outer promise with the
right hand side of the `return` statement. These functions also perform
the DevTools part of the job (aka popping from the promise stack and
sending the debug event). This allows us to get rid of the implicit
try-finally from async functions completely; because the finally
block only called to the %AsyncFunctionPromiseRelease builtin, which
was used to inform DevTools.

In essence we now turn an async function like

```js
async function f(x) { return await bar(x); }
```

into something like this (in Parser and BytecodeGenerator respectively):

```
function f(x) {
  .generator_object = %_AsyncFunctionEnter(.closure, this);
  .promise = %AsyncFunctionCreatePromise();
  try {
    .tmp = await bar(x);
    return %_AsyncFunctionResolve(.promise, .tmp);
  } catch (e) {
    return %_AsyncFunctionReject(.promise, e);
  }
}
```

Overall the bytecode for async functions gets significantly shorter
already (and will get even shorter once we put the outer promise into
the async function generator object). For example the bytecode for a
simple async function

```js
async function f(x) { return await x; }
```

goes from 175 bytes to 110 bytes (a ~38% reduction in size), which
is in particular due to the simplification around the try-finally
removal.

Overall this seems to improve the doxbee-async-es2017-native test by
around 2-3%. On the test case mentioned in v8:8276 we go from
1124ms to 441ms, which corresponds to a 60% reduction in total
execution time!

Tbr: marja@chromium.org
Bug: v8:7253, v8:7522, v8:8276
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Id29dc92de7490b387ff697860c900cee44c9a7a4
Reviewed-on: https://chromium-review.googlesource.com/c/1269041
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56502}
2018-10-10 06:37:53 +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
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
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
adamk
66178c8f53 Remove --harmony-async-await runtime flag
It shipped with Chrome 55 stable.

R=littledan@chromium.org

Review-Url: https://codereview.chromium.org/2621173002
Cr-Commit-Position: refs/heads/master@{#42203}
2017-01-10 23:27:02 +00:00