Check for Extra pointer dereferencing

[jdramani]

Solves issue #7640

[highfive]

Thanks for the pull request, and welcome! The Servo team is excited to review your changes, and you should hear from @Manishearth (or someone else) soon.

[jdramani]

Build failed as expected.

[jdm]

@jdramani Want to fix them, too? :)

[jdm]

Oh, having looked at these changes, I would rather integrate this check into the existing check_rust method, rather than making a new one.

[Manishearth]

Doesn't this make more sense as a check_ty lint, since there may be cases when we want to override it?

[jdm]

@Manishearth: why would we want to override it?

[Manishearth]

In case of APIs that handle generic container &Ts which don't have ?Sized bounds

[nox]

./components/compositing/compositor.rs:694: use &[T] instead of &Vec<T>
./components/compositing/compositor_layer.rs:106: use &[T] instead of &Vec<T>
./components/compositing/compositor_layer.rs:286: use &[T] instead of &Vec<T>
./components/gfx/display_list/mod.rs:207: use &[T] instead of &Vec<T>
./components/net/resource_task.rs:64: use &[T] instead of &Vec<T>
./components/net/resource_task.rs:71: use &[T] instead of &Vec<T>
./components/style/animation.rs:710: use &[T] instead of &Vec<T>
./components/style/animation.rs:711: use &[T] instead of &Vec<T>
./components/style/animation.rs:737: use &[T] instead of &Vec<T>
./components/style/animation.rs:738: use &[T] instead of &Vec<T>
./components/style/animation.rs:797: use &[T] instead of &Vec<T>

[jdm]

Almost there! Like @nox pointed out, this can't merge until the existing problems this picks up are fixed, too :)
-S-awaiting-review

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Reviewed 1 of 1 files at r1, 1 of 1 files at r2, 1 of 1 files at r3.
Review status: 0 of 1 files reviewed at latest revision, 1 unresolved discussion, some commit checks failed.

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^{python/tidy.py, line 310 [r4] (raw file):}
This can be if ": &Vec<" in line:.

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Comments from the review on Reviewable.io

[jdm]

Reviewed 1 of 1 files at r4.
Review status: all files reviewed at latest revision, 1 unresolved discussion, some commit checks failed.

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Comments from the review on Reviewable.io

[bors-servo]

☔ The latest upstream changes (presumably #7680) made this pull request unmergeable. Please resolve the merge conflicts.

[jdm]

-S-awaiting-review -S-fails-tidy +S-needs-code-changes

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Reviewed 5 of 5 files at r5, 4 of 4 files at r6.
Review status: all files reviewed at latest revision, 1 unresolved discussion, some commit checks failed.

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Comments from the review on Reviewable.io

[Manishearth]

It looks like you merged master when you should have rebased. Try rebasing over master:

git checkout master
git pull upstream master
git checkout extra_ptr_dref
git rebase master
git push -f origin extra_ptr_deref

[Manishearth]

Try copying the commands I gave.

[frewsxcv]

In the future, you should not remove these commas

[jdramani]

Pls take a look at this. Tell me if there is any problem

[jdm]

Looks great! Thanks for sticking with it :)

[jdm]

@bors-servo: r+

[bors-servo]

📌 Commit 2a99915 has been approved by jdm

[bors-servo]

⌛ Testing commit 2a99915 with merge 7413a95...

[bors-servo]

💔 Test failed - mac-rel-wpt

[nox]

@bors-servo retry

#7422

[bors-servo]

⌛ Testing commit 2a99915 with merge 9523283...

[bors-servo]

☀️ Test successful - android, gonk, linux-dev, linux-rel, mac-dev-ref-unit, mac-rel-css, mac-rel-wpt