1461450 - AutoTArray<T, N> objects do not have move constructors

Status: RESOLVED FIXED

(Core :: XPCOM, enhancement)

Description

[Nika Layzell [:nika] (ni? for response)]

They only define copy constructors and generic move constructors. A struct which contains an AutoTArray will always copy that array when being moved.

Bug 1185794 points out that it was ignored due to the issues with differently-sized objects, but that doesn't apply to identically-sized types.

We should support moving AutoTArray for identically-sized buffers.

Comment 1

[Nika Layzell [:nika] (ni? for response)]

Attachment: Support moving AutoTArray objects

Comment 2

[Nathan Froyd [:froydnj]]

Comment on attachment 8975648 [details] [diff] [review]
Support moving AutoTArray objects

Review of attachment 8975648 [details] [diff] [review]:
-----------------------------------------------------------------

Tests for this would be ideal.

Comment 3

[Eric Rahm [:erahm]]

Nika, do you have time to get this landed? I think all we need is to add a simple test to `test_move_array` [1].

[1] https://searchfox.org/mozilla-central/rev/1193ef6a61cb6e350460eb2e8468184d3cb0321d/xpcom/tests/gtest/TestTArray2.cpp#300

Comment 4

[Nika Layzell [:nika] (ni? for response)]

Attachment: Part 1: Add move constructors and assignment operators to nsTArray

Comment 5

[Nika Layzell [:nika] (ni? for response)]

Attachment: Part 2: Add tests for AutoTArray move constructors

Comment 6

[Eric Rahm [:erahm]]

Comment on attachment 8990477 [details] [diff] [review]
Part 2: Add tests for AutoTArray move constructors

Review of attachment 8990477 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good, thanks for adding the tests.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/2a02d86bc113
Part 1: Add move constructors and assignment operators to nsTArray, r=froydnj
https://hg.mozilla.org/integration/mozilla-inbound/rev/6e8148c1ca7f
Part 2: Add tests for AutoTArray move constructors, r=erahm

Comment 8

[Andrei Ciure[:aciure]]

Backed out 4 changesets (bug 1461450, bug 1471726) for linting failure xpidl.py

push that caused the backout: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=6e8148c1ca7f2cdf82b4f732aadbf6c8a0d1c212&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-classifiedState=unclassified

failure: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-classifiedState=unclassified&selectedJob=186936069&filter-searchStr=Linting+opt+source-test-mozlint-py-flake8+%28f8%29

log: https://treeherder.mozilla.org/logviewer.html#?job_id=186936069&repo=mozilla-inbound

backout: https://hg.mozilla.org/integration/mozilla-inbound/rev/cddc86531ae9ceed587594be3f9715a43d78efc7

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/a5d04cf5d67f
Part 1: Add move constructors and assignment operators to nsTArray, r=froydnj
https://hg.mozilla.org/integration/mozilla-inbound/rev/44414b1cd32e
Part 2: Add tests for AutoTArray move constructors, r=erahm

Comment 10

[Cristian Brindusan [:cbrindusan]]

Backed out 15 changesets (bug 1475409, bug 1461450, bug 1474369, bug 1471726) for build bustages on xptcstubs_gcc_x86_unix.cpp:55:1.

Backout: https://hg.mozilla.org/integration/mozilla-inbound/rev/113e9ca0b5bccaf3eaee398e789f9b7b8c226009

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=79dbf5b9d8db577bba582a0853eb293d80eed0ba&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&selectedJob=190109107

Failure log: https://treeherder.mozilla.org/logviewer.html#?job_id=190109107&repo=mozilla-inbound&lineNumber=12152

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/961379be0f5e
Part 1: Add move constructors and assignment operators to nsTArray, r=froydnj
https://hg.mozilla.org/integration/mozilla-inbound/rev/c721ada8a6d6
Part 2: Add tests for AutoTArray move constructors, r=erahm

Comment 12

[Cosmin Sabou [:CosminS]]

Backed out for causing rooting hazards and browser chrome failures

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&filter-searchStr=Linux%20x64%20pgo%20Mochitests%20with%20e10s%20test-linux64-pgo%2Fopt-mochitest-browser-chrome-e10s-1%20M-e10s(bc1)&fromchange=7ce27aa3ce6887c226baa88223c0bf95bc2c3c28&tochange=e4f654755cc5cb80fb0a5a91707e8a2eff425e3e&selectedJob=190915193

https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&fromchange=7ce27aa3ce6887c226baa88223c0bf95bc2c3c28&tochange=e4f654755cc5cb80fb0a5a91707e8a2eff425e3e&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=success&filter-classifiedState=unclassified&selectedJob=190903190&filter-searchStr=Linux%20x64%20debug%20hazard-linux64-haz%2Fdebug%20(H)

Failure log: 
browser chrome failures: https://treeherder.mozilla.org/logviewer.html#?job_id=190915193&repo=mozilla-inbound&lineNumber=3614
rooting hazards: https://treeherder.mozilla.org/logviewer.html#?job_id=190903190&repo=mozilla-inbound&lineNumber=47845

Backout link: https://hg.mozilla.org/integration/mozilla-inbound/rev/e4f654755cc5cb80fb0a5a91707e8a2eff425e3e

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/252e00b20a4a
Part 1: Add move constructors and assignment operators to nsTArray, r=froydnj
https://hg.mozilla.org/integration/mozilla-inbound/rev/2084dd0494b5
Part 2: Add tests for AutoTArray move constructors, r=erahm

Comment 14

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/252e00b20a4a
https://hg.mozilla.org/mozilla-central/rev/2084dd0494b5