fix couple of perf related clippy warnings
librustc: don't clone a type that is copy
librustc_incremental: use faster vector initialization
librustc_typeck: don't clone a type that is copy
librustdoc: don't create a vector where a slice will do
librustc: don't clone a type that is copy
librustc_incremental: use faster vector initialization
librustc_typeck: don't clone a type that is copy
librustdoc: don't create a vector where a slice will do
On the backend, rustdoc now emits `paths` entries to a crate's search
index for struct-like enum variants, and index items of type structfield
which belong to such variants point to their variant parents in the
`paths` table, rather than their enum grandparents. The path entry for
a variant is the fully qualified module path plus the enum name.
On the frontend, the search code recognizes structfields belonging to
structlike variants in the `paths` table and re-constructs the URL to
the field's anchor on the enum documentation page.
closes#16017
rustdoc: Fix re-exporting primitive types
* Generate links to the primitive type docs for re-exports.
* Don't ICE on cross crate primitive type re-exports.
* Make primitive type re-exports show up cross crate.
Fixes#67646Closes#67972
r? @GuillaumeGomez
* Generate links to the primitive type docs for re-exports.
* Don't ICE on cross crate primitive type re-exports.
* Make primitive type re-exports show up cross crate.
Implement `?const` opt-out for trait bounds
For now, such bounds are treated exactly the same as unprefixed ones in all contexts. [RFC 2632](https://github.com/rust-lang/rfcs/pull/2632) does not specify whether such bounds are forbidden outside of `const` contexts, so they are allowed at the moment.
Prior to this PR, the constness of a trait bound/impl was stored in `TraitRef`. Now, the constness of an `impl` is stored in `ast::ItemKind::Impl` and the constness of a bound in `ast::TraitBoundModifer`. Additionally, constness of trait bounds is now stored in an additional field of `ty::Predicate::Trait`, and the combination of the constness of the item along with any `TraitBoundModifier` determines the constness of the bound in accordance with the RFC. Encoding the constness of impls at the `ty` level is left for a later PR.
After a discussion in \#wg-grammar on Discord, it was decided that the grammar should not encode the mutual exclusivity of trait bound modifiers. The grammar for trait bound modifiers remains `[?const] [?]`. To encode this, I add a dummy variant to `ast::TraitBoundModifier` that is used when the syntax `?const ?` appears. This variant causes an error in AST validation and disappears during HIR lowering.
cc #67794
r? @oli-obk
rustdoc: Catch fatal errors when syntax highlighting
For some errors the lexer will unwind so we need to handle that in addition to handling `token::Unknown`.
Fixes#56885
r? @GuillaumeGomez
