1677224 - Use tagged index in ParserScopeData

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P1)

Description

[Tooru Fujisawa [:arai]]

Just like bug 1675804, we can use tagged index in scope data.
we have topmost 2-bit available in TaggedParserAtomIndex, and we can use them for ClosedOverFlag and TopLevelFunctionFlag

Comment 1

[Tooru Fujisawa [:arai]]

Attachment: Bug 1677224 - Part 1: Use TaggedParserAtomIndex in ParserScopeData. r=nbp

• Replace ParserAtom pointer with TaggedParserAtomIndex in ParserScopeData
  • Add TaggedParserAtomIndex specialization for AbstractBindingName,
    in order to store closed-over and top-level-function flag in
    highest bits of TaggedParserAtomIndex
  • Moved existing implementation of AbstractBindingName to
    JSAtom specialization

Comment 2

[Tooru Fujisawa [:arai]]

Attachment: Bug 1677224 - Part 2: Encode/decode trailing names at once. r?nbp!

Now trailing names is an array of TaggedParserAtomIndex, and can be
encoded/decoded by codeBytes.

Depends on D99299

Comment 3

[Tooru Fujisawa [:arai]]

Attachment: Bug 1677224 - Part 3: Remove XDRParserAtomOrNull. r?nbp!

Depends on D99300

Comment 4

[Tooru Fujisawa [:arai]]

Attachment: Bug 1677224 - Part 4: Remove XDRParserAtom. r?nbp!

Depends on D99301

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2d9a14218c49
Part 1: Use TaggedParserAtomIndex in ParserScopeData. r=nbp
https://hg.mozilla.org/integration/autoland/rev/b46b9e2360f6
Part 2: Encode/decode trailing names at once. r=nbp
https://hg.mozilla.org/integration/autoland/rev/9f10e3fb773b
Part 3: Remove XDRParserAtomOrNull. r=nbp
https://hg.mozilla.org/integration/autoland/rev/0ff8fe67a6ae
Part 4: Remove XDRParserAtom. r=nbp

Comment 6

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/2d9a14218c49
https://hg.mozilla.org/mozilla-central/rev/b46b9e2360f6
https://hg.mozilla.org/mozilla-central/rev/9f10e3fb773b
https://hg.mozilla.org/mozilla-central/rev/0ff8fe67a6ae

Comment 7

[Atila Butkovits]

Backed out for casuing build bustage.

Backout link: https://hg.mozilla.org/integration/autoland/rev/3677691a0aee918bf1bbe9bf0e335b47483415a3

Push with failure: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&resultStatus=testfailed%2Cbusted%2Cexception&revision=0ff8fe67a6ae46d9d42337670e2cc9c618b4fd8c&searchStr=Linux%2Cx64%2Cdebug%2Cbuild-linux64-base-toolchains%2Fdebug%2CBb

Failure log: https://treeherder.mozilla.org/logviewer?job_id=324543943&repo=autoland&lineNumber=135444

Comment 8

[Tooru Fujisawa [:arai]]

there seems to be some heap corruption or something in BumpChunk.

it crashes while poisoning trailing array here
https://searchfox.org/mozilla-central/rev/8883276967d39918e2ce64e873afdd432fb406ca/js/src/vm/Scope.h#265-267

the memory block is inside the chunk allocated by the following, and so far I don't see the block gets freed.
https://searchfox.org/mozilla-central/rev/8883276967d39918e2ce64e873afdd432fb406ca/js/src/ds/LifoAlloc.cpp#31

Comment 9

[Tooru Fujisawa [:arai]]

no, it's not memory corruption.
it's just that we shouldn't use poison for non-pointer-size-aligned memory block.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1cdeca7d522e
Part 1: Use TaggedParserAtomIndex in ParserScopeData. r=nbp
https://hg.mozilla.org/integration/autoland/rev/6cf94ea511b2
Part 2: Encode/decode trailing names at once. r=nbp
https://hg.mozilla.org/integration/autoland/rev/98c42effee5c
Part 3: Remove XDRParserAtomOrNull. r=nbp
https://hg.mozilla.org/integration/autoland/rev/b2d6946fb3a2
Part 4: Remove XDRParserAtom. r=nbp

Comment 11

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Backout merged: https://hg.mozilla.org/mozilla-central/rev/3677691a0aee

Comment 12

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/1cdeca7d522e
https://hg.mozilla.org/mozilla-central/rev/6cf94ea511b2
https://hg.mozilla.org/mozilla-central/rev/98c42effee5c
https://hg.mozilla.org/mozilla-central/rev/b2d6946fb3a2