Implement selection via new trait solver
Implements selection via the new solver by calling into `assemble_and_evaluate_candidates`, doing a very light-weight "winnow" to choose one candidate over the others, and then re-confirming that candidate outside of the `EvalCtxt` in order to compute the information necessary for the `ImplSource`.
This selection routine is best effort -- if it receives an ambiguous response from the `EvalCtxt`, then it may return ambiguity if the work to re-confirm the goal is not "easy" -- right now, that means everything except for object and impl goals. Since we don't want to reimplement all of the work of the `compute_builtin_*` methods in the solver internals, we bail out if we encounter ambiguity more often than the old solver. This should only barely affect [method selection](f798ada7ba/compiler/rustc_hir_typeck/src/method/probe.rs (L1447)) and not codegen. It can be made more precise later if needed.
r? `@lcnr`
Revert "Suggest `x build library` for a custom toolchain that fails to load `core`"
This reverts commit b913f5593d2e2698d18034b56dd538ee745f1adc.
CI builds with profile=nightly, causing different test output.
Making the output depend on the release channel was not a great idea and we have to be more careful with this.
I did not realize that the change could have such effects on test output but it's kinda obvious with hindsight >.<.
This reverts commit b913f5593d2e2698d18034b56dd538ee745f1adc.
CI builds with profile=nightly, causing different test output.
Making the output depend on the release channel was not a great idea.
Extend previous checks for external ABI fn-ptrs to use in internal
statics, constants, type aliases and algebraic data types.
Signed-off-by: David Wood <david.wood@huawei.com>
Extend previous commit's support for checking for external fn-ptrs in
internal fn types to report errors for multiple found fn-ptrs.
Signed-off-by: David Wood <david.wood@huawei.com>
Instead of skipping functions with internal ABIs, check that the
signature doesn't contain any fn-ptr types with external ABIs that
aren't FFI-safe.
Signed-off-by: David Wood <david.wood@huawei.com>
vec tets: ensure pointer is still writeable
Under Tree Borrows, a pointer can become read-only: still allowing reads but not permitting writes any more. So these tests that want to check that pointers remain valid need to do writes to ensure that pointers indeed remain fully valid.
Updates the descriptions of the various ARM targets in platform-support.md so they are a little more consistent.
For example, all instances of ARMv7 changed to ARMv7-A (as opposed to ARMv7-R and ARMv7-M).
implement deep normalization via the new solver
together with #112869 this should remove all uses of the old solver with `-Ztrait-solver=next`.
see https://hackmd.io/V0qsUB_fTxexfQO_pcOcrg for a description of this PR. Will move that doc to the `rustc-dev-guide` after merging this.
r? `@compiler-errors`
Rollup of 3 pull requests
Successful merges:
- #113253 (Fixed documentation of from<CString> for Rc<CStr>: Arc -> Rc)
- #113258 (Migrate GUI colors test to original CSS color format)
- #113259 (Suggest `x build library` for a custom toolchain that fails to load `core`)
r? `@ghost`
`@rustbot` modify labels: rollup
Rewrite `UnDerefer`
Currently, `UnDerefer` is used by drop elaboration to undo the effects of the `Derefer` pass. However, it just recreates the original places with derefs in the middle of the projection. Because `ProjectionElem::Deref` is intended to be removed completely in the future, this will not work forever.
This PR introduces a `deref_chain` method that returns the places behind `DerefTemp` locals in a place and rewrites the move path code to use this. In the process, `UnDerefer` was merged into `MovePathLookup`. Now that move paths use the same places as in the MIR, the other uses of `UnDerefer` no longer require it.
See #98145
cc `@ouz-a`
r? `@oli-obk`
