3fc70e8d46
Take 2: Implement object-safety and dynamic dispatch for arbitrary_self_types This replaces #50173. Over the months that that PR was open, we made a lot of changes to the way this was going to be implemented, and the long, meandering comment thread and commit history would have been confusing to people reading it in the future. So I decided to package everything up with new, straighforward commits and open a new PR. Here are the main points. Please read the commit messages for details. - To simplify codegen, we only support receivers that have the ABI of a pointer. That means they are builtin pointer types, or newtypes thereof. - We introduce a new trait: `DispatchFromDyn<T>`, similar to `CoerceUnsized<T>`. `DispatchFromDyn` has extra requirements that `CoerceUnsized` does not: when you implement `DispatchFromDyn` for a struct, there cannot be any extra fields besides the field being coerced and `PhantomData` fields. This ensures that the struct's ABI is the same as a pointer. - For a method's receiver (e.g. `self: Rc<Self>`) to be object-safe, it needs to have the following property: - let `DynReceiver` be the receiver when `Self = dyn Trait` - let `ConcreteReceiver` be the receiver when `Self = T`, where `T` is some unknown `Sized` type that implements `Trait`, and is the erased type of the trait object. - `ConcreteReceiver` must implement `DispatchFromDyn<DynReceiver>` In the case of `Rc<Self>`, this requires `Rc<T>: DispatchFromDyn<Rc<dyn Trait>>` These rules are explained more thoroughly in the doc comment on `receiver_is_dispatchable` in object_safety.rs. r? @nikomatsakis and @eddyb cc @arielb1 @cramertj @withoutboats Special thanks to @nikomatsakis for getting me un-stuck when implementing the object-safety checks, and @eddyb for helping with the codegen parts. EDIT 2018-11-01: updated because CoerceSized has been replaced with DispatchFromDyn |
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| .. | ||
| bootstrap | ||
| build_helper | ||
| ci | ||
| dlmalloc@c99638dc2e | ||
| doc | ||
| etc | ||
| grammar | ||
| jemalloc@1f5a28755e | ||
| liballoc | ||
| liballoc_jemalloc | ||
| liballoc_system | ||
| libarena | ||
| libbacktrace@f4d02bbdbf | ||
| libcompiler_builtins@939cbca6e9 | ||
| libcore | ||
| libfmt_macros | ||
| libgraphviz | ||
| liblibc@1844a772b6 | ||
| libpanic_abort | ||
| libpanic_unwind | ||
| libproc_macro | ||
| libprofiler_builtins | ||
| librustc | ||
| librustc_allocator | ||
| librustc_apfloat | ||
| librustc_asan | ||
| librustc_borrowck | ||
| librustc_codegen_llvm | ||
| librustc_codegen_utils | ||
| librustc_cratesio_shim | ||
| librustc_data_structures | ||
| librustc_driver | ||
| librustc_errors | ||
| librustc_fs_util | ||
| librustc_incremental | ||
| librustc_lint | ||
| librustc_llvm | ||
| librustc_lsan | ||
| librustc_metadata | ||
| librustc_metadata_utils | ||
| librustc_mir | ||
| librustc_msan | ||
| librustc_passes | ||
| librustc_platform_intrinsics | ||
| librustc_plugin | ||
| librustc_privacy | ||
| librustc_resolve | ||
| librustc_save_analysis | ||
| librustc_target | ||
| librustc_traits | ||
| librustc_tsan | ||
| librustc_typeck | ||
| librustdoc | ||
| libserialize | ||
| libstd | ||
| libsyntax | ||
| libsyntax_ext | ||
| libsyntax_pos | ||
| libterm | ||
| libtest | ||
| libunwind | ||
| llvm@7051ead40a | ||
| llvm-emscripten@2717444753 | ||
| rtstartup | ||
| rustc | ||
| rustllvm | ||
| stdsimd@431766a3fb | ||
| test | ||
| tools | ||
| .gitignore | ||
| Cargo.lock | ||
| Cargo.toml | ||
| README.md | ||
| stage0.txt | ||
This directory contains the source code of the rust project, including:
rustcand its testslibstd- Various submodules for tools, like rustdoc, rls, etc.
For more information on how various parts of the compiler work, see the rustc guide.
Their is also useful content in the following READMEs, which are gradually being moved over to the guide:
- https://github.com/rust-lang/rust/tree/master/src/librustc/ty/query
- https://github.com/rust-lang/rust/tree/master/src/librustc/dep_graph
- https://github.com/rust-lang/rust/blob/master/src/librustc/infer/region_constraints
- https://github.com/rust-lang/rust/tree/master/src/librustc/infer/higher_ranked
- https://github.com/rust-lang/rust/tree/master/src/librustc/infer/lexical_region_resolve