rustdoc: Replace where-bounded Clean impl with simple function
This is the first step in removing the Clean impls for tuples. Either way, this
significantly simplifies the code since it reduces the amount of "trait magic".
(To clarify, I'm referring to impls like `impl Clean for (A, B)`, not Clean impls
that work on tuples in the user's program.)
cc ``@jyn514``
This function parameter attribute was introduced in https://github.com/rust-lang/rust/pull/44866 as an intermediate step in implementing `impl Trait`, it's not necessary or used anywhere by itself.
Otherwise, rustdoc panics with messages like this:
thread 'rustc' panicked at 'assertion failed: cx.impl_trait_bounds.is_empty()',
src/librustdoc/clean/utils.rs:462:5
This ordering requirement is unrelated to the `clean_fn_decl_with_args`
refactoring, but the requirement was uncovered as part of that change.
I'm not sure if *all* of these places have the requirement, but I added
comments to them just in case.
Basically, this entails moving the arguments cleaning to the call site.
I extracted several local variables because:
1. It makes the code easier to read and understand.
2. If I hadn't, the extra `clean()` calls would have caused complicated
tuples to be split across several lines.
3. I couldn't just extract local variables for `args` because then the
arguments would be cleaned *before* the generics, while rustdoc expects
them to be cleaned *after*. Only extracting `args` caused panics like
this:
thread 'rustc' panicked at 'assertion failed: cx.impl_trait_bounds.is_empty()',
src/librustdoc/clean/utils.rs:462:5
Extracting variables makes the control flow -- and the required
order of cleaning -- more explicit.
This was the only Clean impl I found with `where` bounds.
This impl was doubly-confusing: it was implemented on a tuple and it
was polymorphic. Combined, this caused a "spooky action at a distance"
effect to make the code very confusing.
Type inference for inline consts
Fixes#78132Fixes#78174Fixes#81857Fixes#89964
Perform type checking/inference of inline consts in the same context as the outer def, similar to what is currently done to closure.
Doing so would require `closure_base_def_id` of the inline const to return the outer def, and since `closure_base_def_id` can be called on non-local crate (and thus have no HIR available), a new `DefKind` is created for inline consts.
The type of the generated anon const can capture lifetime of outer def, so we couldn't just use the typeck result as the type of the inline const's def. Closure has a similar issue, and it uses extra type params `CK, CS, U` to capture closure kind, input/output signature and upvars. I use a similar approach for inline consts, letting it have an extra type param `R`, and then `typeof(InlineConst<[paremt generics], R>)` would just be `R`. In borrowck region requirements are also propagated to the outer MIR body just like it's currently done for closure.
With this PR, inline consts in expression position are quitely usable now; however the usage in pattern position is still incomplete -- since those does not remain in the MIR borrowck couldn't verify the lifetime there. I have left an ignored test as a FIXME.
Some disucssions can be found on [this Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/260443-project-const-generics/topic/inline.20consts.20typeck).
cc `````@spastorino````` `````@lcnr`````
r? `````@nikomatsakis`````
`````@rustbot````` label A-inference F-inline_const T-compiler
Merge `DocContext.{ty,lt,ct}_substs` into one map
It should be impossible to have more than one entry with a particular
key across the three maps, so they should be one map. In addition to
making it impossible for multiple entries to exist, this should improve
memory usage since now only one map is allocated on the stack and heap.
r? `@GuillaumeGomez`
This change has two advantages:
1. It makes the possible states clearer, and it makes it impossible to
construct invalid states, such as a blanket impl that is also an auto
trait impl.
2. It shrinks the size of `Impl` a bit, since now there is only one
field, rather than two.
It should be impossible to have more than one entry with a particular
key across the three maps, so they should be one map. In addition to
making it impossible for multiple entries to exist, this should improve
memory usage since now only one map is allocated on the stack and heap.
It is only used in one place; `src` was about a third of `Crate`'s total
size; `Crate` is frequently moved by-value; and `src` can be easily
computed on-demand.
Before, it was only measuring one callsite of `build_impl`, and it
incremented the call count even if `build_impl` returned early because
the `did` was already inlined.
Now, it measures all calls, minus calls that return early.
It should be preferred over `def_id_no_primitives()`, so it should have
a shorter name. I also put it before `def_id_no_primitives()` so that it
shows up first in the docs.
The old name was confusing because it's easy to assume that using
`def_id()` is fine, but in some situations it's incorrect. In general,
`def_id_full()` should be preferred, so `def_id_full()` should have a
shorter name. That will happen in the next commit.
Now that it's only implemented for `Type`, using inherent methods
instead means that imports are no longer necessary. Also, `GetDefId` is
only meant to be used with `Type`, so it shouldn't be a trait.
rustdoc: Box some fields of `GenericParamDefKind` to reduce size
This change shrinks `GenericParamDef` from 120 to 56 bytes. `GenericParamDef` is
used a lot, so the extra indirection should hopefully be worth the size savings.
r? `@ghost`
