836742 - BaselineCompiler: Fix debugger test failures

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Comment 1

[Jan de Mooij [:jandem]]

Turns out many debugger tests use the debugger-statement, and these scripts use SETALISEDVAR in the prologue to store the arguments object.

So compiling *ALIASEDVAR uncovered some debugger problems, going to attach some patches to address these first.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Part 1: Fix StackIter argsObj, computeThis to work with baseline frames

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Part 2: IonFrame_Bailed_* changes

In ion::HandleException, we loop over all frames to close live iterators, and the baseline compiler also looks for catch-handlers. If it finds a catch block, it jumps to it.

In debug mode this is wrong though: we call OnPop and OnExceptionUnwind debugger hooks, and these can query the top most frame. So if ion::HandleException moves past a BaselineJS frame, it has to pop the frame immediately by updating ionTop.

The easiest way to do this is by reusing EnsureExitFrame. This is the m-c part, let me know if you can think of another way to do this.

Comment 4

[Nicolas B. Pierron [:nbp]]

Comment on attachment 709060 [details] [diff] [review]
Part 2: IonFrame_Bailed_* changes

Review of attachment 709060 [details] [diff] [review]:
-----------------------------------------------------------------

Exporting EnsureExitFrame(IonCommonFrameLayout *frame), r=me
Renaming Bailed_* to Exit_* is boggus as there is no ExitFrame tag on the stack.  As discussed on IRC, Unwind_* / Unwound_* would be better for sharing them with Baseline frame exception handling (which might stop on frmae pop).

Comment 5

[Jan de Mooij [:jandem]]

Part 1:

https://hg.mozilla.org/projects/ionmonkey/rev/b70cb746c192

Comment 6

[Jan de Mooij [:jandem]]

Attachment: Part 2: IonFrame_Bailed_* changes, v2

Now uses IonFrame_Unwound_* instead of IonFrame_Exit_*

Comment 7

[Jan de Mooij [:jandem]]

Part 2:

https://hg.mozilla.org/integration/mozilla-inbound/rev/872e3eb6841e

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/872e3eb6841e

Comment 9

[Jan de Mooij [:jandem]]

Attachment: Part 3: Baseline patch

Fixes the debug/Frame-live-02.js failure + adds an extra test that also failed without the patch.

Comment 10

[Jan de Mooij [:jandem]]

https://hg.mozilla.org/projects/ionmonkey/rev/44981f029a24