With this CL we use interrupt for pause in two cases:
- when we process Debugger.pause on interruption,
- when we would like to break as soon as possible after OOM.
In all other cases, e.g. for async step into we use break
on function call by calling StepIn debugger action.
In mentioned cases we should not actually use interrupt as well:
- Debugger.pause in this case scheduled using interrupt and we
may just break right now without requesting another interrupt,
unfortunately blink side is not ready,
- we should use more reliable way to break right after near OOM
callback, otherwise we can get this callback, increase limit,
request break on next interrupt, before interrupt get another
huge memory allocation and crash.
There are couple advantages:
- we get much better break locations for async stepping
(see inspector tests expectations),
- we can remove DEBUG_BREAK interruption
(it should speedup blackboxing with async tasks, see
removed todo in debug.cc for details)
- it is required preparation step for async step out,
(see https://chromium-review.googlesource.com/c/v8/v8/+/1054618)
Bug: v8:7753
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Iabd7627dbffa9a0eab1736064caf589d02591926
Reviewed-on: https://chromium-review.googlesource.com/1054155
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53439}
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}
V8 has internal mechanism to ignore steps and breaks inside internal scripts, in this CL it's reused for blackboxing implementation.
Advantages:
- much faster blackboxing implementation (before we at least wrap and collect current call stack for each step),
- get rid of StepFrame action and potential pause in blackboxed code after N StepFrame steps,
- simplification of debugger agent logic.
Disadvtanges:
- currently when user was paused in blackboxed code (e.g. on breakpoint) and then makes step action, debugger ignores blackboxed state of the script and allows to use step actions as usual - this behavior is regressed, we still able to support it on frontend side.
Current state and proposed changes for blackboxing: https://docs.google.com/document/d/1hnzaXPAN8_QC5ENxIgxgMNDbXLraM_OXT73rAyijTF8/edit?usp=sharing
BUG=v8:5842
R=yangguo@chromium.org,dgozman@chromium.org,alph@chromium.org
Review-Url: https://codereview.chromium.org/2633803002
Cr-Commit-Position: refs/heads/master@{#42614}
