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}
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}
This CL further extends the debug wrapper, migrates around 60 tests, and
removes a few tests that use functionality we will not support anymore.
In more detail:
* Removed tests that use:
* enable/disable individual breakpoints
* invocationText()
* the ScriptCollected event
* showBreakPoints
* evalFromScript (and similar)
* mirror.constructedBy and mirror.referencedBy
* event_data.promise()
* Some frame.evaluate uses were adapted since due to differences between
remote objects (inspector) and mirrors. For instance, exceptions are
currently not recreated exactly, since the inspector protocol does not
give us the stack and message separately. Other objects (such as
'this' in debug-evaluate-receiver-before-super) need to be explicitly
converted to a string before the test works correctly.
* Ensure that inspector stores the script before sending ScriptParsed and
ScriptFailedToParse events in order to be able to use the script from
within those events.
* Better remote object reconstruction (e.g. for undefined and arrays).
* New functionality in wrapper:
* debuggerFlags().breakPointsActive.setValue()
* scripts()
* execState.setVariableValue()
* execState.scopeObject().value()
* execState.scopeObject().property()
* execState.frame().allScopes()
* eventData.exception()
* eventData.script()
* setBreakPointsActive()
BUG=v8:5530
Review-Url: https://codereview.chromium.org/2497973002
Cr-Commit-Position: refs/heads/master@{#41019}
