Replace return_address usage for rooting with stack guards and convenience macros. #11872

eddyb · 2016-06-26T15:23:15Z

The existing Rooted and RootedVec users were migrated the the following two macros:

let x = Rooted::new(cx, value);
// Was changed to:
rooted!(in(cx) let x = value);
// Which expands to:
let mut __root = Rooted::new_unrooted(value);
let x = RootedGuard::new(cx, &mut __root);

let mut v = RootedVec::new();
v.extend(iterator);
// Was changed to:
rooted_vec!(let v <- iterator);
// Which expands to:
let mut __root = RootableVec::new();
let v = RootedVec::new(&mut __root, iterator);

The rooted! macro depends on servo/rust-mozjs#272.
These APIs based on two types, a container to be rooted and a rooting guard, allow implementing both Rooted-style rooting and Traceable-based rooting in stable Rust, without abusing return_address.

Such macros may have been tried before, but in 1.9 their hygiene is broken, they work only since 1.10.

Sadly, Rooted is a FFI type and completely exposed, so I cannot prevent anyone from creating their own, although all fields but the value get overwritten by RootedGuard::new anyway.
RootableVec OTOH is guaranteed to be empty when not rooted, which makes it harmless AFAICT.

By fixing rust-lang/rust#34227, this PR enables Servo to build with -Zorbit.

./mach build -d does not report any errors
./mach test-tidy does not report any errors
These changes fix rust-lang/rust#34227
These changes do not require tests because they are not functional changes

This change is

highfive · 2016-06-26T15:23:17Z

Heads up! This PR modifies the following files:

@KiChjang: components/script/dom/xmlhttprequest.rs, components/script/dom/range.rs, components/script/dom/htmlscriptelement.rs, components/script/devtools.rs, components/script/dom/document.rs, components/script/dom/eventtarget.rs, components/script/timers.rs, components/script/dom/browsingcontext.rs, components/script/dom/bindings/callback.rs, components/script/dom/workerglobalscope.rs, components/script/dom/bindings/error.rs, components/script/lib.rs, components/script/dom/bindings/codegen/CodegenRust.py, components/script/dom/worker.rs, components/script/webdriver_handlers.rs, components/script/dom/bindings/interface.rs, components/script/dom/macros.rs, components/script/dom/eventdispatcher.rs, components/script/dom/serviceworker.rs, components/script/Cargo.toml, components/script/dom/errorevent.rs, components/script/dom/dedicatedworkerglobalscope.rs, components/script/dom/bindings/proxyhandler.rs, components/script/dom/bindings/utils.rs, components/script/script_thread.rs, components/script/dom/messageevent.rs, components/script/dom/htmliframeelement.rs, components/script/dom/node.rs, components/script/dom/webglrenderingcontext.rs, components/script/dom/bindings/trace.rs, components/script/dom/websocket.rs, components/script/dom/serviceworkerglobalscope.rs
@emilio: components/script/dom/webglrenderingcontext.rs

highfive · 2016-06-26T15:23:18Z

Warning

These commits modify unsafe code. Please review it carefully!
These commits modify script code, but no tests are modified. Please consider adding a test!

jdm · 2016-06-26T15:29:46Z

@bors-servo: try

bors-servo · 2016-06-26T15:29:49Z

⌛ Trying commit 07328e7 with merge 91b36f4...


        Auto merge of #11872 - eddyb:back-to-roots, r=<try>

Replace return_address usage for rooting with stack guards and convenience macros. The existing `Rooted` and `RootedVec` users were migrated the the following two macros: ```rust let x = Rooted::new(cx, value); // Was changed to: rooted!(in(cx) let x = value); // Which expands to: let mut __root = Rooted::new_unrooted(value); let x = RootedGuard::new(cx, &mut __root); ``` ```rust let mut v = RootedVec::new(); v.extend(iter); // Was changed to: rooted_vec!(let v = iter); // Which expands to: let mut __root = RootableVec::new(); let v = RootedVec::new(&mut __root, iter); ``` These APIs based on two types, a container to be rooted and a rooting guard, allow implementing both `Rooted`-style rooting and `Traceable`-based rooting in stable Rust, without abusing `return_address`. Sadly, `Rooted` is a FFI type and completely exposed, so I cannot prevent anyone from creating their own, although all fields but the value get overwritten by `RootedGuard::new` anyway. `RootableVec` OTOH is *guaranteed* to be empty when not rooted, which makes it harmless AFAICT. --- - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [x] These changes fix rust-lang/rust#34227 - [x] These changes do not require tests because they are not functional changes  --- This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11872)

Manishearth · 2016-06-26T15:31:36Z

components/script/dom/macros.rs

+#[macro_export]
+macro_rules! rooted_vec {
+    (let $name:ident = $iter:expr) => {
+        let mut __root = $crate::dom::bindings::trace::RootableVec::new_unrooted();


make these unsafe and make the macro safe?

oh I see what you did there

bors-servo · 2016-06-26T15:33:18Z

💔 Test failed - linux-dev

Manishearth · 2016-06-26T15:33:44Z

r? @jdm

The design for RootedVec seems sound to me (will look at rooted! later), but I'm not as familiar with the intricacies of these bindings as jdm is

Manishearth · 2016-06-26T15:33:56Z

   Compiling glutin_app v0.0.1 (file:///home/servo/buildbot/slave/linux-dev/build/ports/glutin)
/home/servo/buildbot/slave/linux-dev/build/components/script/webdriver_handlers.rs:31:41: 31:55 error: unresolved import `js::jsapi::UndefinedValue`. There is no `UndefinedValue` in `js::jsapi` [E0432]
/home/servo/buildbot/slave/linux-dev/build/components/script/webdriver_handlers.rs:31 use js::jsapi::{JSContext, HandleValue, UndefinedValue};
                                                                                                                              ^~~~~~~~~~~~~~

cbrewster · 2016-06-26T16:43:18Z

@bors-servo try

bors-servo · 2016-06-26T16:43:21Z

⌛ Trying commit b1d2f75 with merge 1b404d5...


        Auto merge of #11872 - eddyb:back-to-roots, r=<try>

Replace return_address usage for rooting with stack guards and convenience macros. The existing `Rooted` and `RootedVec` users were migrated the the following two macros: ```rust let x = Rooted::new(cx, value); // Was changed to: rooted!(in(cx) let x = value); // Which expands to: let mut __root = Rooted::new_unrooted(value); let x = RootedGuard::new(cx, &mut __root); ``` ```rust let mut v = RootedVec::new(); v.extend(iter); // Was changed to: rooted_vec!(let v = iter); // Which expands to: let mut __root = RootableVec::new(); let v = RootedVec::new(&mut __root, iter); ``` The `rooted!` macro depends on servo/rust-mozjs#272. These APIs based on two types, a container to be rooted and a rooting guard, allow implementing both `Rooted`-style rooting and `Traceable`-based rooting in stable Rust, without abusing `return_address`. Such macros may have been tried before, but in 1.9 their hygiene is broken, they work only since 1.10. Sadly, `Rooted` is a FFI type and completely exposed, so I cannot prevent anyone from creating their own, although all fields but the value get overwritten by `RootedGuard::new` anyway. `RootableVec` OTOH is *guaranteed* to be empty when not rooted, which makes it harmless AFAICT. --- - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [x] These changes fix rust-lang/rust#34227 - [x] These changes do not require tests because they are not functional changes  --- This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11872)

bors-servo · 2016-06-26T17:35:05Z

💔 Test failed - linux-rel

eddyb · 2016-06-26T17:38:39Z

I think I have a fix for /_mozilla/mozilla/sequence-hole.html - the Vec<T> FromJSConvertible in jsapi::conversions wasn't unrooting properly.
Is /html/semantics/embedded-content/the-iframe-element/change_parentage.html a legitimate failure?

FWIW, those are the only failures I've seen with -Zorbit on, which is probably good news!

jdm · 2016-06-26T17:56:16Z

change_parentage is #11703.

eddyb · 2016-06-26T18:09:19Z

@jdm The convertible failure is fixed FWIW, I just checked (with -Zorbit no less!). Also, although dromaero is ridiculously variable, switching to MIR seems to universally drop the times down, so that's something (again, if it's not completely random variance). Someone else should look into it.


        Auto merge of #34491 - eddyb:return-in-peace, r=nagisa

@pcwalton

Remove the return_address intrinsic. This intrinsic to get the return pointer was introduced in #16248 / #16081 by @pcwalton for Servo. However, as explained in #34227, it's impossible to ensure it's used correctly, and it broke with `-Zorbit`. Servo's usage is being replaced in servo/servo#11872, and I expect nobody else to have abused it. But I've also started a crater run, just in case this is a `[breaking-change]` for anyone else.

bors-servo · 2016-07-04T17:34:39Z

📌 Commit 9584669 has been approved by Ms2ger

bors-servo · 2016-07-04T17:44:41Z

⌛ Testing commit 9584669 with merge 162af13...


        Auto merge of #11872 - eddyb:back-to-roots, r=Ms2ger

Replace return_address usage for rooting with stack guards and convenience macros. The existing `Rooted` and `RootedVec` users were migrated the the following two macros: ```rust let x = Rooted::new(cx, value); // Was changed to: rooted!(in(cx) let x = value); // Which expands to: let mut __root = Rooted::new_unrooted(value); let x = RootedGuard::new(cx, &mut __root); ``` ```rust let mut v = RootedVec::new(); v.extend(iterator); // Was changed to: rooted_vec!(let v <- iterator); // Which expands to: let mut __root = RootableVec::new(); let v = RootedVec::new(&mut __root, iterator); ``` The `rooted!` macro depends on servo/rust-mozjs#272. These APIs based on two types, a container to be rooted and a rooting guard, allow implementing both `Rooted`-style rooting and `Traceable`-based rooting in stable Rust, without abusing `return_address`. Such macros may have been tried before, but in 1.9 their hygiene is broken, they work only since 1.10. Sadly, `Rooted` is a FFI type and completely exposed, so I cannot prevent anyone from creating their own, although all fields but the value get overwritten by `RootedGuard::new` anyway. `RootableVec` OTOH is *guaranteed* to be empty when not rooted, which makes it harmless AFAICT. By fixing rust-lang/rust#34227, this PR enables Servo to build with `-Zorbit`. --- - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [x] These changes fix rust-lang/rust#34227 - [x] These changes do not require tests because they are not functional changes  --- This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11872)

bors-servo · 2016-07-04T17:48:05Z

💔 Test failed - linux-dev


        Switch to using the new rooted!/RootedGuard API for rooting.


        Use a stack guard and a macro for RootedVec instead of return_address.

jdm · 2016-07-04T18:03:33Z

@bors-servo: r=Ms2ger

bors-servo · 2016-07-04T18:03:34Z

📌 Commit b79a7d4 has been approved by Ms2ger

bors-servo · 2016-07-04T18:03:36Z

⌛ Testing commit b79a7d4 with merge 80cb0cf...


        Auto merge of #11872 - eddyb:back-to-roots, r=Ms2ger

Replace return_address usage for rooting with stack guards and convenience macros. The existing `Rooted` and `RootedVec` users were migrated the the following two macros: ```rust let x = Rooted::new(cx, value); // Was changed to: rooted!(in(cx) let x = value); // Which expands to: let mut __root = Rooted::new_unrooted(value); let x = RootedGuard::new(cx, &mut __root); ``` ```rust let mut v = RootedVec::new(); v.extend(iterator); // Was changed to: rooted_vec!(let v <- iterator); // Which expands to: let mut __root = RootableVec::new(); let v = RootedVec::new(&mut __root, iterator); ``` The `rooted!` macro depends on servo/rust-mozjs#272. These APIs based on two types, a container to be rooted and a rooting guard, allow implementing both `Rooted`-style rooting and `Traceable`-based rooting in stable Rust, without abusing `return_address`. Such macros may have been tried before, but in 1.9 their hygiene is broken, they work only since 1.10. Sadly, `Rooted` is a FFI type and completely exposed, so I cannot prevent anyone from creating their own, although all fields but the value get overwritten by `RootedGuard::new` anyway. `RootableVec` OTOH is *guaranteed* to be empty when not rooted, which makes it harmless AFAICT. By fixing rust-lang/rust#34227, this PR enables Servo to build with `-Zorbit`. --- - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [x] These changes fix rust-lang/rust#34227 - [x] These changes do not require tests because they are not functional changes  --- This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11872)

bors-servo · 2016-07-04T18:58:53Z

☀️ Test successful - android, arm32, arm64, linux-dev, linux-rel, mac-dev-unit, mac-rel-css, mac-rel-wpt, windows


        Auto merge of #34648 - eddyb:return-in-peace-pls, r=nagisa

Revert "Revert "Remove the return_address intrinsic."" This reverts commit f698cd3. Made possible by the merge of servo/servo#11872, this closes #34227 for good.


        Remove rust_tenacious

We don't use it anymore since #11872.


        Remove rust_tenacious

We don't use it anymore since servo#11872.

highfive assigned Manishearth Jun 26, 2016

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eddyb force-pushed the eddyb:back-to-roots branch from 12250ba to 07328e7 Jun 26, 2016

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highfive added the S-tests-failed label Jun 26, 2016

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This was referenced Jun 26, 2016

Remove the return_address intrinsic. rust-lang/rust#34491

Merged

Switch to MIR-based translation by default. rust-lang/rust#34096

Merged

highfive assigned Ms2ger and unassigned jdm Jul 4, 2016

highfive added S-awaiting-merge and removed S-awaiting-review labels Jul 4, 2016

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eddyb added 2 commits Jul 4, 2016

Switch to using the new rooted!/RootedGuard API for rooting.

0db1faf

Use a stack guard and a macro for RootedVec instead of return_address.

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b79a7d4

eddyb force-pushed the eddyb:back-to-roots branch from 9584669 to b79a7d4 Jul 4, 2016

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highfive added S-awaiting-merge and removed S-awaiting-review labels Jul 4, 2016

bors-servo merged commit b79a7d4 into servo:master Jul 4, 2016
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Integrate service worker manager thread #11727

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Revert "Revert "Remove the return_address intrinsic."" rust-lang/rust#34648

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nox added a commit that referenced this pull request Aug 13, 2016

Remove rust_tenacious

f12fad7

We don't use it anymore since #11872.

samuknet added a commit to samuknet/servo that referenced this pull request Sep 6, 2016

Remove rust_tenacious

d830666

We don't use it anymore since servo#11872.

servo / servo

Replace return_address usage for rooting with stack guards and convenience macros. #11872

Replace return_address usage for rooting with stack guards and convenience macros. #11872

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Replace return_address usage for rooting with stack guards and convenience macros. #11872

Replace return_address usage for rooting with stack guards and convenience macros. #11872

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