Keep **all** the obligations for every projection is wasteful of
memory and compilation time. We only really care about those
subobligations that may inform the result of the projection (i.e., may
help to resolve any inference variables that appear within).
Therefore, we can clear the subobligations from the cache that don't
potentially affect the result of the projection. On every cache hit,
we also take the opportunity to check if the type variables have been
resolved *yet* and, if so, clear out the pending obligations.
Fixes#43613
Use hir::ItemLocalId instead of ast::NodeId in rustc::middle::region::CodeExtent.
This is an alternative to @michaelwoerister's #43887, changing `CodeExtent` instead of `ReScope`.
The benefit here is that the same `Region`s are used same-crate and cross-crate, while preserving the incremental recompilation properties of the stable `hir::ItemLocalId`.
Only places which needed to get back to the `ast::NodeId` from `CodeExtent` was its `span` method, used in error reporting - passing the `&RegionMaps` down allowed using `hir_to_node_id`.
`rustc::cfg` and `dataflow` also had to be converted to `hir::ItemLocalId` because of their interactions with `CodeExtent`, especially in `borrowck`, and from that we have 3 more `hir_to_node_id` calls: `cfg::graphviz` node labels, `borrowck` move reporting, and the `unconditional_recursion` lint.
Out of all of those, *only* the lint actually makes a decision (on whether code will compile) based on the result of the conversion, the others only use it to know how to print information to the user.
So I think we're safe to say that the bulk of the code working with a `CodeExtent` is fine with local IDs.
r? @nikomatsakis
add `fn` to syntax of rustc::ty::maps::define_maps
This is not a functional change, it just makes it possible to find a query by grepping without knowing that it's a query rather than a function.
I didn't pursue renaming everything from "map" to "query" because it seems to be a very invasive change. It would be a good test to exercise an IDE's renaming features.
Closes#44161
r? @eddyb
rustbuild: update the rust-src filter for compiler-rt
We wanted `src/compiler-rt/test` filtered from the `rust-src` package,
but that path is now `src/libcompiler_builtins/compiler-rt/test`. This
saves over half of the installed rust-src size. (50MB -> 22MB)
We wanted `src/compiler-rt/test` filtered from the `rust-src` package,
but that path is now `src/libcompiler_builtins/compiler-rt/test`. This
saves over half of the installed rust-src size. (50MB -> 22MB)
rustc: Remove `specialization_cache` in favor of a query
This commit removes the `specialization_cache` field of `TyCtxt` by moving it to
a dedicated query, which it turned out was already quite easily structured to do
so!
cc #44137
Forward-compatibly deny drops in constants if they *could* actually run.
This is part of #40036, specifically the checks for user-defined destructor invocations on locals which *may not* have been moved away, the motivating example being:
```rust
const FOO: i32 = (HasDrop {...}, 0).1;
```
The evaluation of constant MIR will continue to create `'static` slots for more locals than is necessary (if `Storage{Live,Dead}` statements are ignored), but it shouldn't be misusable.
r? @nikomatsakis
Initial diagnostic API for proc-macros.
This commit introduces the ability to create and emit `Diagnostic` structures from proc-macros, allowing for proc-macro authors to emit warning, error, note, and help messages just like the compiler does.
The API is somewhat based on the diagnostic API already present in `rustc` with several changes that improve usability. The entry point into the diagnostic API is a new `Diagnostic` type which is primarily created through new `error`, `warning`, `help`, and `note` methods on `Span`. The `Diagnostic` type records the diagnostic level, message, and optional `Span` for the top-level diagnostic and contains a `Vec` of all of the child diagnostics. Child diagnostics can be added through builder methods on `Diagnostic`.
A typical use of the API may look like:
```rust
let token = parse_token();
let val = parse_val();
val.span
.error(format!("expected A but found {}", val))
.span_note(token.span, "because of this token")
.help("consider using a different token")
.emit();
```
cc @jseyfried @nrc @dtolnay @alexcrichton
rustc: Fix proc_macro expansions on trait methods
This commit fixes procedural macro attributes being attached to trait methods,
ensuring that they get resolved and expanded as other procedural macro
attributes. The bug here was that `current_module` on the resolver was
accidentally set to be a trait when it's otherwise only ever expecting a
`mod`/block module. The actual fix here came from @jseyfried, I'm just helping
to land it in the compiler!
Closes#42493
