Decompose Adjustment into smaller steps and remove the method map.
The method map held method callee information for:
* actual method calls (`x.f(...)`)
* overloaded unary, binary, indexing and call operators
* *every overloaded deref adjustment* (many can exist for each expression)
That last one was a historical ~~accident~~ hack, and part of the motivation for this PR, along with:
* a desire to compose adjustments more freely
* containing the autoderef logic better to avoid mutation within an inference snapshot
* not creating `TyFnDef` types which are incompatible with the original one
* i.e. we used to take a`TyFnDef`'s `for<'a> &'a T -> &'a U` signature and instantiate `'a` using a region inference variable, *then* package the resulting `&'b T -> &'b U` signature in another `TyFnDef`, while keeping *the same* `DefId` and `Substs`
* to fix#3548 by explicitly writing autorefs for the RHS of comparison operators
Individual commits tell their own story, of "atomic" changes avoiding breaking semantics.
Future work based on this PR could include:
* removing the signature from `TyFnDef`, now that it's always "canonical"
* some questions of variance remain, as subtyping *still* treats the signature differently
* moving part of the typeck logic for methods, autoderef and coercion into `rustc::traits`
* allowing LUB coercions (joining multiple expressions) to "stack up" many adjustments
* transitive coercions (e.g. reify or unsize after multiple steps of autoderef)
r? @nikomatsakis
rustdoc: Cleanup associated const value rendering
Rather than (ab)using Debug for outputting the type in plain text use the
alternate format parameter which already does exactly that. This fixes
type parameters for example which would output raw HTML.
Also cleans up adding parens around references to trait objects.
Rather than (ab)using Debug for outputting the type in plain text use the
alternate format parameter which already does exactly that. This fixes
type parameters for example which would output raw HTML.
Also cleans up adding parens around references to trait objects.
Explain why a closure is `FnOnce` in closure errors.
Issue: #42065
@nikomatsakis Am I going the right direction with this?
~~I am stuck in a few bits:~~
~~1. How to trace the code to get the upvar instead of the original variable's span?~~
~~2. How to find the node id of the upvar where the move occured?~~
incr.comp.: Track expanded spans instead of FileMaps.
This PR removes explicit tracking of FileMaps in response to #42101. The reasoning behind being able to just *not* track access to FileMaps is similar to why we don't track access to the `DefId->DefPath` map:
1. One can only get ahold of a `Span` value by accessing the HIR (for local things) or a `metadata::schema::Entry` (for things from external crates).
2. For both of these things we compute a hash that incorporates the *expanded spans*, that is, what we hash is in the (FileMap independent) format `filename:line:col`.
3. Consequently, everything that emits a span should already be tracked via its dependency to something that has the span included in its hash and changes would be detected via that hash.
One caveat here is that we have to be conservative when exporting things in metadata. A crate can be built without debuginfo and would thus by default not incorporate most spans into the metadata hashes. However, a downstream crate can make an inline copy of things in the upstream crate and span changes in the upstream crate would then go undetected, even if the downstream uses them (e.g. by emitting debuginfo for an inlined function). For this reason, we always incorporate spans into metadata hashes for now (there might be more efficient ways to handle this safely when red-green tracking is implemented).
r? @nikomatsakis
Translate array drop glue using MIR
I was a bit lazy here and used a usize-based index instead of a pointer iteration. Do you think this is important @eddyb?
r? @eddyb
This fixes leakage on panic with arrays & slices. I am using a C-style
for-loop instead of a pointer-based loop because that would be ugly-er
to implement.
extend `struct_tail` to operate over tuples
Not 100% sure why this got exposed when it wasn't before, but this struct definitely seems wrong.
Fixes#42110
r? @eddyb
trace_macro: Show both the macro call and its expansion. #42072.
See #42072 for the initial motivation behind this.
The change is not the minimal fix, but I want this behavior almost every time I use `trace_macros`.
Fix 'associate type' typo
I came across an error message mentioning an 'associate type'.
Since this is the only instance of this term in rustc (it's 'associated type' everywhere else), I think this might be a typo.
Make assignments to `Copy` union fields safe
This is an accompanying PR to PR https://github.com/rust-lang/rust/pull/42068 stabilizing FFI unions.
This was first proposed in https://github.com/rust-lang/rust/issues/32836#issuecomment-281296416, see subsequent comments as well.
Assignments to `Copy` union fields do not read any data from the union and are [equivalent](https://github.com/rust-lang/rust/issues/32836#issuecomment-281660298) to whole union assignments, which are safe, so they should be safe as well. This removes a significant number of "false positive" unsafe blocks, in code dealing with FFI unions in particular.
It desirable to make this change now, together with stabilization of FFI unions, because now it affecfts only unstable code, but later it will cause warnings/errors caused by `unused_unsafe` lint in stable code.
cc #32836
r? @nikomatsakis
add thiscall calling convention support
This support is needed for bindgen to work well on 32-bit Windows, and also enables people to begin experimenting with C++ FFI support on that platform.
Fixes#42044.
