Add simple async drop glue generation
This is a prototype of the async drop glue generation for some simple types. Async drop glue is intended to behave very similar to the regular drop glue except for being asynchronous. Currently it does not execute synchronous drops but only calls user implementations of `AsyncDrop::async_drop` associative function and awaits the returned future. It is not complete as it only recurses into arrays, slices, tuples, and structs and does not have same sensible restrictions as the old `Drop` trait implementation like having the same bounds as the type definition, while code assumes their existence (requires a future work).
This current design uses a workaround as it does not create any custom async destructor state machine types for ADTs, but instead uses types defined in the std library called future combinators (deferred_async_drop, chain, ready_unit).
Also I recommend reading my [explainer](https://zetanumbers.github.io/book/async-drop-design.html).
This is a part of the [MCP: Low level components for async drop](https://github.com/rust-lang/compiler-team/issues/727) work.
Feature completeness:
- [x] `AsyncDrop` trait
- [ ] `async_drop_in_place_raw`/async drop glue generation support for
- [x] Trivially destructible types (integers, bools, floats, string slices, pointers, references, etc.)
- [x] Arrays and slices (array pointer is unsized into slice pointer)
- [x] ADTs (enums, structs, unions)
- [x] tuple-like types (tuples, closures)
- [ ] Dynamic types (`dyn Trait`, see explainer's [proposed design](https://github.com/zetanumbers/posts/blob/main/async-drop-design.md#async-drop-glue-for-dyn-trait))
- [ ] coroutines (https://github.com/rust-lang/rust/pull/123948)
- [x] Async drop glue includes sync drop glue code
- [x] Cleanup branch generation for `async_drop_in_place_raw`
- [ ] Union rejects non-trivially async destructible fields
- [ ] `AsyncDrop` implementation requires same bounds as type definition
- [ ] Skip trivially destructible fields (optimization)
- [ ] New [`TyKind::AdtAsyncDestructor`](https://github.com/zetanumbers/posts/blob/main/async-drop-design.md#adt-async-destructor-types) and get rid of combinators
- [ ] [Synchronously undroppable types](https://github.com/zetanumbers/posts/blob/main/async-drop-design.md#exclusively-async-drop)
- [ ] Automatic async drop at the end of the scope in async context
miri libstd tests: test windows-msvc instead of windows-gnu
This avoids https://github.com/rust-lang/rust/issues/123583. MSVC is the more widely used target anyway AFAIK, so probably makes more sense to cover that.
Update books
## rust-lang/book
41 commits in 3131aa4642c627a24f523c82566b94a7d920f68c..d207d894cc5e1d496ab99beeacd1a420e5d4d238
2024-04-19 19:48:19 UTC to 2024-04-08 19:34:07 UTC
- Ch. 2: intentionally use `{}` at first (rust-lang/book#3898)
- Inline fmt lints for `redirects/` (rust-lang/book#3897)
- ch12-03: `expect` is not used multitude times by this chapter (rust-lang/book#3287)
- Inline format args to `tools/src` (rust-lang/book#3896)
- Improve awkward phrasing around the kinds of closures (rust-lang/book#3290)
- Ch. 14: clarify workspace dependency reuse (rust-lang/book#3890)
- Edit on line no. 153. Replaced fn add_to_waitlist with fn eat_at_restaurant. (rust-lang/book#3281)
- Ch. 2: less ambiguity about numbers (rust-lang/book#3895)
- Clarified first slices paragraph (rust-lang/book#3363)
- Inline all format arguments (rust-lang/book#3385)
- Use v1.58 captured ident formatting in examples (rust-lang/book#3048)
- Revert "ch18-03: Guarded match arm exhaustivness clarification" (rust-lang/book#3894)
- Ch. 18: further clarify about irrefutable patterns (rust-lang/book#3893)
- ch18-02: Minor corrections (rust-lang/book#3381)
- Make style of listings 9-7 and 9-8 consistent with 9-6 (rust-lang/book#3217)
- ch18-03: Guarded match arm exhaustivness clarification (rust-lang/book#3397)
- ch11-03: Unnecessary import removal (rust-lang/book#3284)
- Update ch20-01-single-threaded.md (rust-lang/book#3394)
- In Appendix D, adds hyperlink to Appendix E (rust-lang/book#3418)
- Chapter 13-03 fixed Iterator 'type' to 'trait' (rust-lang/book#3433)
- Fix the expected substring in ch11-01 (rust-lang/book#3534)
- Ch. 17: clarify 'in order to compile' (rust-lang/book#3892)
- Revert "Chapter 15-05: Fix incorrect interpretation of compiler error" (rust-lang/book#3891)
- Chapter 15-05: Fix incorrect interpretation of compiler error (rust-lang/book#3501)
- Remove direction to authenticate with `cargo login {API token}` (rust-lang/book#3506)
- Update syn dependencies in Chapter 19 to 2.0 (rust-lang/book#3888)
- Chapter 3: Clarify `return` vs. `break`. (rust-lang/book#3889)
- Fix "`Display` type" to "`Display` trait" in ch19-03 (rust-lang/book#3835)
- Update listings in ch 11-01 to reflect current output from cargo new (rust-lang/book#3533)
- Fix "`test` module" to "`tests` module" in ch11-03 (rust-lang/book#3579)
- Ch. 2: fix wording about `cargo update` (rust-lang/book#3882)
- Remove hebrew niqqud in 8-14 String::from example (rust-lang/book#3648)
- Ch. 16: fix a grammar issue (rust-lang/book#3881)
- Update MSVC instructions (rust-lang/book#3616)
- Replace RLS with rust-analyzer in ch00 (rust-lang/book#3546)
- Fix em dashes (rust-lang/book#3570)
- Revert #3711 (rust-lang/book#3880)
- Procedure Macro: Update dependencies (rust-lang/book#3631)
- Parity with rustup's help (rust-lang/book#3642)
- Fix confusing sentence (rust-lang/book#3877)
- Ch. 7: add a note about the need for `pub` in one more place (rust-lang/book#3879)
## rust-lang/edition-guide
2 commits in eb3eb80e106d03250c1fb7c5666b1c8c59672862..0c68e90acaae5a611f8f5098a3c2980de9845ab2
2024-04-16 21:23:55 UTC to 2024-04-15 16:05:32 UTC
- Document RustcEncodable/RustcDecodable (rust-lang/edition-guide#298)
- Flesh out detail behind disallowing refs to static mut (rust-lang/edition-guide#299)
## rust-lang/reference
5 commits in 55694913b1301cc809f9bf4a1ad1b3d6920efbd9..5854fcc286557ad3ab34d325073d11d8118096b6
2024-04-21 13:47:07 UTC to 2024-04-15 16:12:40 UTC
- Stabilize Wasm target features that are in phase 4 and 5 (rust-lang/reference#1420)
- Expand and clarify primitive alignment (rust-lang/reference#1493)
- Update clone reference to include closures (rust-lang/reference#1492)
- Document how `non_exhaustive` interacts with tuple and unit-like structs. (rust-lang/reference#1491)
- Fix link to RISC-V Zkt spec; it was pointing to Zkr (rust-lang/reference#1490)
## rust-lang/rustc-dev-guide
4 commits in b77a34bd46399687b4ce6a17198e9f316c988794..07425fed36b00e60341c5e29e28d37d40cbd4451
2024-04-13 15:16:44 UTC to 2024-04-08 19:00:54 UTC
- Add a note about checks with multiple revisions (rust-lang/rustc-dev-guide#1963)
- compiletest: clarify that headers must be one header per line (rust-lang/rustc-dev-guide#1962)
- chore: fix some typos in conments (rust-lang/rustc-dev-guide#1961)
- compiletest: specify which special env var and which particular CI job (rust-lang/rustc-dev-guide#1960)
Improve ICE message for forbidden dep-graph reads.
The new message mentions the main context that the ICE might occur in and it mentions the query/dep-node that is being read.
cc https://github.com/rust-lang/rust/pull/123781, where this would have been helpful.
coverage: Prepare for improved branch coverage
When trying to rebase my new branch coverage work (including #124154) on top of the introduction of MC/DC coverage (#123409), I found it a lot harder than anticipated. With the benefit of hindsight, the branch coverage code and MC/DC code have become more interdependent than I'm happy with.
This PR therefore disentangles them a bit, so that it will be easier for both areas of code to evolve independently without interference.
---
This PR also includes a few extra branch coverage tests that I had sitting around from my current branch coverage work. They mostly just demonstrate that certain language constructs listed in #124118 currently don't have branch coverage support.
``@rustbot`` label +A-code-coverage
[cleanup] [llvm backend] Prevent creating the same `Instance::mono` multiple times
Just a little thing I came across while going through the code.
r? ```@oli-obk```
checked_ilog: improve performance
Addresses #115874.
(This PR replicates the original #115875, which I accidentally closed by deleting my forked repository...)
Ignore `-C strip` on MSVC
tl;dr - Define `-Cstrip` to only ever affect the binary; no other build artifacts.
This is necessary to improve cross-platform behavior consistency: if someone wanted debug information to be contained only in separate files on all platforms, they would set `-Cstrip=symbols` and `-Csplit-debuginfo=packed`, but this would result in no PDB files on MSVC.
Resolves#114215
This clears the way for larger changes to how branches are handled by the
coverage instrumentor, in order to support branch coverage for more language
constructs.
Rollup of 3 pull requests
Successful merges:
- #124240 (add a couple tests for fixed ICEs.)
- #124245 (bootstrap: Promote some build_steps comments to docs)
- #124246 (Add comma at one place in `abs()` documentation)
r? `@ghost`
`@rustbot` modify labels: rollup
bootstrap: Promote some build_steps comments to docs
No new content, just makes some comments readable when viewing the docs with `--document-private-items`.
Fix ICE when there is a non-Unicode entry in the incremental crate directory
Fix the ICE that occurs when there is a non-Unicode entry in the incremental crate directory by replacing uses of `to_string_lossy` + `assert_no_characters_lost` with `to_str`. The added test would cause the compiler to ICE before this PR.
Add an intrinsic for `ptr::from_raw_parts(_mut)`
Fixes#123174
cc `@CAD97` `@saethlin`
r? `@cjgillot`
As suggested in https://github.com/rust-lang/rust/pull/123190#issuecomment-2028717967, this adds a new `AggregateKind::RawPtr` for creating a pointer from its data pointer and its metadata.
That means that `slice::from_raw_parts` and friends no longer need to hard-code pointer layout into `libcore`, and because it no longer does union hacks the MIR is shorter and more amenable to optimizations.
fix normalizing in different `ParamEnv`s with the same `InferCtxt`
This PR changes the key of the projection cache from just `AliasTy` to `(AliasTy, ParamEnv)` to allow normalizing in different `ParamEnv`s without resetting caches. Previously, normalizing the same alias in different param envs would always reuse the cached result from the first normalization, which is incorrect if the projection clauses in the param env have changed.
Fixing this bug allows us to get rid of `InferCtxt::clear_caches`, which was only used by the `AutoTraitFinder`, because it requires normalizing in different param envs.
r? `@fmease`
