1662073 - Various RegExp/Irregexp cleanups

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P2)

Description

[André Bargull [:anba]]

Umbrella issue for various small clean-ups in RegExp/Irregexp code:

• Update "make_unicode.py" to work under Python 3.7.
• Remove no longer needed code from "make_unicode.py".
• Remove effectively dead code in RegExp code.
• Avoid unnecessary rooting in RegExp named capturing code.
• ...

Comment 1

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 1: Make make_unicode.py Python3.7 compatible (PEP 479). r=iain!

next() throws StopIteration when the iterator has been exhausted. Before
PEP 479, throwing StopIteration implicitly closes a generator and is not
propagated to the caller. After PEP 479, the StopIteration error is propagated
to the caller.

Comment 2

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 2: Removed no longer used Unicode case folding macros. r=iain!

These macros were used by the local irregexp copy to implement Unicode RegExps.
They have been replaced by calls to ICU.

Depends on D88789

Comment 3

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 3: Remove irregexp table generation from Unicode script. r=iain!

The files generated by these functions were already removed.

Depends on D88790

Comment 4

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 4: Remove unnecessary assignment to `skip` out-param in InterpretDollar. r=iain!

The skip out-param is only read when InterpretDollar returns true, so we
can remove both assignments which are followed by return false.

Drive-by change:

• Move another assignment to skip to appear directly before return true, so
  it's more obvious that skip only needs to be set on success.
• Add a blank line before a comment, per our normal style guides.

Depends on D88791

Comment 5

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 5: Remove unnecessary rooting for RegExp named captures. r=iain!

Remove unnecessary rooting and move a rooting variable outside of a loop. Sadly
we still don't have static analysis to catch this (bug 1362038).

Drive-by change:

• Add more blank lines before comments.

Depends on D88792

Comment 6

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 6: Use ranged for-loops in RegExp named capturing code. r=iain!

These two loops can be simplified to use ranged for-loops, reducing a bit of
boilerplate code.

Depends on D88793

Comment 7

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 7: Assert named capturing groups array length is divisible by two. r=iain!

It seems nice to also assert the array length is divisible by two, given that
the array is created entirely elsewhere.

Depends on D88794

Comment 8

[André Bargull [:anba]]

Attachment: Bug 1662073 - Part 8: Add `getShared` accessor to RegExp object. r=iain!

Add a getShared accessor to RegExpObject to retrieve a previously assigned
RegExpShared object. And then replace two calls to the fallible
RegExpObject::getShared() method with the new accessor. This way we can
avoid calling a fallible method whose return value is ignored.

Depends on D88795

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d77322fe8d1b
Part 1: Make make_unicode.py Python3.7 compatible (PEP 479). r=iain
https://hg.mozilla.org/integration/autoland/rev/d69b33dc4238
Part 2: Removed no longer used Unicode case folding macros. r=iain
https://hg.mozilla.org/integration/autoland/rev/9b07e4b58ce1
Part 3: Remove irregexp table generation from Unicode script. r=iain
https://hg.mozilla.org/integration/autoland/rev/747a630e409c
Part 4: Remove unnecessary assignment to `skip` out-param in InterpretDollar. r=iain
https://hg.mozilla.org/integration/autoland/rev/de9376528044
Part 5: Remove unnecessary rooting for RegExp named captures. r=iain
https://hg.mozilla.org/integration/autoland/rev/2fc5e4134cf1
Part 6: Use ranged for-loops in RegExp named capturing code. r=iain
https://hg.mozilla.org/integration/autoland/rev/7d6facecd556
Part 7: Assert named capturing groups array length is divisible by two. r=iain
https://hg.mozilla.org/integration/autoland/rev/c5bdc46e971b
Part 8: Add `getShared` accessor to RegExp object. r=iain

Comment 10

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/d77322fe8d1b
https://hg.mozilla.org/mozilla-central/rev/d69b33dc4238
https://hg.mozilla.org/mozilla-central/rev/9b07e4b58ce1
https://hg.mozilla.org/mozilla-central/rev/747a630e409c
https://hg.mozilla.org/mozilla-central/rev/de9376528044
https://hg.mozilla.org/mozilla-central/rev/2fc5e4134cf1
https://hg.mozilla.org/mozilla-central/rev/7d6facecd556
https://hg.mozilla.org/mozilla-central/rev/c5bdc46e971b