Change untagged_unions to not allow union fields with drop by SimonSapin · Pull Request #62330 · rust-lang/rust

SimonSapin · 2019-07-03T12:21:41Z

This is a rebase of #56440, massaged to solve merge conflicts and make the test suite pass.

Change untagged_unions to not allow union fields with drop

Union fields may now never have a type with attached destructor. This for example allows unions to use arbitrary field types only by wrapping them in ManuallyDrop (or similar).

The stable rule remains, that union fields must be Copy. We use the new rule for the untagged_union feature.

Tracking issue: #55149

rust-highfive · 2019-07-03T12:21:46Z

Some changes occurred in diagnostic error codes

cc @GuillaumeGomez

rust-highfive · 2019-07-03T12:21:48Z

r? @eddyb

(rust_highfive has picked a reviewer for you, use r? to override)

Centril · 2019-07-03T17:08:07Z

cc tracking issue: #55149

bors · 2019-07-05T21:59:48Z

☔ The latest upstream changes (presumably #62419) made this pull request unmergeable. Please resolve the merge conflicts.

eddyb · 2019-07-11T10:04:34Z

r? @RalfJung

bors · 2019-07-27T23:09:37Z

☔ The latest upstream changes (presumably #63029) made this pull request unmergeable. Please resolve the merge conflicts.

JohnTitor · 2019-08-04T08:03:41Z

Ping from triage: @SimonSapin, any updates on this? you should also resolve conflicts.

SimonSapin · 2019-08-05T16:01:58Z

Rebased, but I’m not the original author of this code so I feel I’m not able to answer some of the review comments. I’d appreciate if someone more familiar with compiler internals is willing to take over.

rust-highfive · 2019-08-05T17:34:49Z

The job x86_64-gnu-llvm-6.0 of your PR failed (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

2019-08-05T16:19:33.6312378Z ##[command]git remote add origin https://github.com/rust-lang/rust
2019-08-05T16:19:33.6505965Z ##[command]git config gc.auto 0
2019-08-05T16:19:33.6589564Z ##[command]git config --get-all http.https://github.com/rust-lang/rust.extraheader
2019-08-05T16:19:33.6644934Z ##[command]git config --get-all http.proxy
2019-08-05T16:19:33.6787047Z ##[command]git -c http.extraheader="AUTHORIZATION: basic ***" fetch --force --tags --prune --progress --no-recurse-submodules --depth=2 origin +refs/heads/*:refs/remotes/origin/* +refs/pull/62330/merge:refs/remotes/pull/62330/merge
---
2019-08-05T16:20:10.3163046Z do so (now or later) by using -b with the checkout command again. Example:
2019-08-05T16:20:10.3163076Z 2019-08-05T16:20:10.3163283Z git checkout -b <new-branch-name>
2019-08-05T16:20:10.3163496Z 2019-08-05T16:20:10.3163563Z HEAD is now at a91151e62 Merge d2a4d5732f55204b21d0fc0b6ca31375e26f74df into 4be067558962c004b638e4c6f162d50f7c0c98b6
2019-08-05T16:20:10.3322060Z ##[section]Starting: Collect CPU-usage statistics in the background
2019-08-05T16:20:10.3324878Z ==============================================================================
2019-08-05T16:20:10.3324935Z Task : Bash
2019-08-05T16:20:10.3324981Z Description : Run a Bash script on macOS, Linux, or Windows
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---
2019-08-05T17:34:25.9845824Z failures:
2019-08-05T17:34:25.9873366Z 2019-08-05T17:34:25.9874167Z ---- [ui] ui/union/union-with-drop-fields-lint-rpass.rs stdout ----
2019-08-05T17:34:25.9874347Z 2019-08-05T17:34:25.9874870Z error: test compilation failed although it shouldn't!
2019-08-05T17:34:25.9875048Z status: exit code: 1
2019-08-05T17:34:25.9875973Z command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "-Zui-testing" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/union/union-with-drop-fields-lint-rpass/a" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/union/union-with-drop-fields-lint-rpass/auxiliary" "-A" "unused"
2019-08-05T17:34:25.9876593Z ------------------------------------------
2019-08-05T17:34:25.9876741Z 2019-08-05T17:34:25.9877079Z ------------------------------------------
2019-08-05T17:34:25.9877238Z stderr:
2019-08-05T17:34:25.9877238Z stderr:
2019-08-05T17:34:25.9877589Z ------------------------------------------
2019-08-05T17:34:25.9877751Z warning: unknown lint: `unions_with_drop_fields`
2019-08-05T17:34:25.9878339Z |
2019-08-05T17:34:25.9878339Z |
2019-08-05T17:34:25.9878470Z LL | #![allow(unions_with_drop_fields)]
2019-08-05T17:34:25.9878751Z |
2019-08-05T17:34:25.9878873Z = note: `#[warn(unknown_lints)]` on by default
2019-08-05T17:34:25.9879000Z 2019-08-05T17:34:25.9879124Z error[E0740]: unions may not contain fields that need dropping
2019-08-05T17:34:25.9879124Z error[E0740]: unions may not contain fields that need dropping
2019-08-05T17:34:25.9879503Z --> /checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs:12:5
2019-08-05T17:34:25.9879687Z |
2019-08-05T17:34:25.9879808Z LL | a: String, // OK
2019-08-05T17:34:25.9880064Z |
2019-08-05T17:34:25.9880186Z note: `std::mem::ManuallyDrop` can be used to wrap the type
2019-08-05T17:34:25.9880554Z --> /checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs:12:5
2019-08-05T17:34:25.9880997Z |
2019-08-05T17:34:25.9880997Z |
2019-08-05T17:34:25.9881199Z LL | a: String, // OK
2019-08-05T17:34:25.9881677Z 2019-08-05T17:34:25.9881895Z error[E0740]: unions may not contain fields that need dropping
2019-08-05T17:34:25.9882380Z --> /checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs:20:5
2019-08-05T17:34:25.9882578Z |
2019-08-05T17:34:25.9882578Z |
2019-08-05T17:34:25.9882698Z LL | a: S, // OK
2019-08-05T17:34:25.9882953Z |
2019-08-05T17:34:25.9883077Z note: `std::mem::ManuallyDrop` can be used to wrap the type
2019-08-05T17:34:25.9883466Z --> /checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs:20:5
2019-08-05T17:34:25.9883632Z |
2019-08-05T17:34:25.9883632Z |
2019-08-05T17:34:25.9883751Z LL | a: S, // OK
2019-08-05T17:34:25.9883988Z 2019-08-05T17:34:25.9884351Z error[E0740]: unions may not contain fields that need dropping
2019-08-05T17:34:25.9884848Z --> /checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs:25:5
2019-08-05T17:34:25.9885030Z |
2019-08-05T17:34:25.9885030Z |
2019-08-05T17:34:25.9885150Z LL | a: T, // OK
2019-08-05T17:34:25.9885412Z |
2019-08-05T17:34:25.9885533Z note: `std::mem::ManuallyDrop` can be used to wrap the type
2019-08-05T17:34:25.9885922Z --> /checkout/src/test/ui/union/union-with-drop-fields-lint-rpass.rs:25:5
2019-08-05T17:34:25.9886088Z |
2019-08-05T17:34:25.9886088Z |
2019-08-05T17:34:25.9886207Z LL | a: T, // OK
2019-08-05T17:34:25.9886445Z 2019-08-05T17:34:25.9886566Z error: aborting due to 3 previous errors
2019-08-05T17:34:25.9886667Z 2019-08-05T17:34:25.9887046Z For more information about this error, try `rustc --explain E0740`.
---
2019-08-05T17:34:25.9915626Z thread 'main' panicked at 'Some tests failed', src/tools/compiletest/src/main.rs:536:22
2019-08-05T17:34:25.9915876Z note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
2019-08-05T17:34:25.9942831Z 2019-08-05T17:34:26.8257846Z 2019-08-05T17:34:26.8298815Z command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/usr/lib/llvm-6.0/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--target-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python2.7" "--lldb-python" "/usr/bin/python2.7" "--gdb" "/usr/bin/gdb" "--quiet" "--llvm-version" "6.0.0\n" "--system-llvm" "--cc" "" "--cxx" "" "--cflags" "" "--llvm-components" "" "--llvm-cxxflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"
2019-08-05T17:34:26.8299091Z 2019-08-05T17:34:26.8299136Z 2019-08-05T17:34:26.8299186Z failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test
2019-08-05T17:34:26.8299239Z Build completed unsuccessfully in 1:07:58
2019-08-05T17:34:26.8299239Z Build completed unsuccessfully in 1:07:58
2019-08-05T17:34:26.8357601Z ##[error]Bash exited with code '1'.
2019-08-05T17:34:26.8411585Z ##[section]Starting: Checkout
2019-08-05T17:34:26.8413222Z ==============================================================================
2019-08-05T17:34:26.8413283Z Task : Get sources
2019-08-05T17:34:26.8413350Z Description : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

RalfJung · 2019-10-21T17:29:37Z

That fixes my reservations. :)

Let's finally do this... thanks to everyone involved! @bors r+

bors · 2019-10-21T17:29:38Z

📌 Commit 875bdd5 has been approved by RalfJung

bors · 2019-10-21T19:46:23Z

⌛ Testing commit 875bdd5 with merge da66b096c142097755e3474b7f1b3f2dafd61f9a...

… r=RalfJung Change untagged_unions to not allow union fields with drop This is a rebase of rust-lang#56440, massaged to solve merge conflicts and make the test suite pass. Change untagged_unions to not allow union fields with drop Union fields may now never have a type with attached destructor. This for example allows unions to use arbitrary field types only by wrapping them in `ManuallyDrop` (or similar). The stable rule remains, that union fields must be `Copy`. We use the new rule for the `untagged_union` feature. Tracking issue: rust-lang#55149

Centril · 2019-10-21T19:49:21Z

@bors retry rolled up.

bors · 2019-10-21T19:56:59Z

⌛ Testing commit 875bdd5 with merge b3e8ca17bd0ec17cd42fb43f92ff37e4a72fa7b1...

… r=RalfJung Change untagged_unions to not allow union fields with drop This is a rebase of rust-lang#56440, massaged to solve merge conflicts and make the test suite pass. Change untagged_unions to not allow union fields with drop Union fields may now never have a type with attached destructor. This for example allows unions to use arbitrary field types only by wrapping them in `ManuallyDrop` (or similar). The stable rule remains, that union fields must be `Copy`. We use the new rule for the `untagged_union` feature. Tracking issue: rust-lang#55149

Centril · 2019-10-21T20:01:30Z

@bors retry rolled up.

@ghost

Rollup of 7 pull requests Successful merges: - #62330 (Change untagged_unions to not allow union fields with drop) - #65092 (make is_power_of_two a const function) - #65621 (miri: add write_bytes method to Memory doing bounds-checks and supporting iterators) - #65647 (Remove unnecessary trait bounds and derivations) - #65653 (keep the root dir clean from debugging) - #65660 (Rename `ConstValue::Infer(InferConst::Canonical(..))` to `ConstValue::Bound(..)`) - #65663 (Fix typo from #65214) Failed merges: r? @ghost

bluss · 2019-10-23T09:49:38Z

Awesome. Thanks to all that worked on this!

SimonSapin added A-destructors Area: Destructors (`Drop`, …) B-RFC-approved Blocker: Approved by a merged RFC but not yet implemented. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jul 3, 2019

rust-highfive assigned eddyb Jul 3, 2019

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jul 3, 2019

Centril reviewed Jul 3, 2019
View reviewed changes

SimonSapin mentioned this pull request Jul 4, 2019
WIP: rewrite based on MaybeUninit and #[repr(usize)] enumservo/rust-smallvec#157
Closed

SimonSapin force-pushed the no-drop-in-union-fields branch from a51a67a to 81949b0Compare July 4, 2019 16:35

SimonSapin force-pushed the no-drop-in-union-fields branch from 81949b0 to 0951ccaCompare July 5, 2019 22:04

rust-highfive assigned RalfJung and unassigned eddyb Jul 11, 2019