3050: Refactor type parameters, implement argument position impl trait r=matklad a=flodiebold
I wanted to implement APIT by lowering to type parameters because we need to do that anyway for correctness and don't need Chalk support for it; this grew into some more wide-ranging refactoring of how type parameters are handled 😅
- use Ty::Bound instead of Ty::Param to represent polymorphism, and explicitly
count binders. This gets us closer to Chalk's way of doing things, and means
that we now only use Param as a placeholder for an unknown type, e.g. within
a generic function. I.e. we're never using Param in a situation where we want
to substitute it, and the method to do that is gone; `subst` now always works
on bound variables. (This changes how the types of generic functions print;
previously, you'd get something like `fn identity<i32>(T) -> T`, but now we
display the substituted signature `fn identity<i32>(i32) -> i32`, which I think
makes more sense.)
- once we do this, it's more natural to represent `Param` by a globally unique
ID; the use of indices was mostly to make substituting easier. This also
means we fix the bug where `Param` loses its name when going through Chalk.
- I would actually like to rename `Param` to `Placeholder` to better reflect its use and
get closer to Chalk, but I'll leave that to a follow-up.
- introduce a context for type lowering, to allow lowering `impl Trait` to
different things depending on where we are. And since we have that, we can
also lower type parameters directly to variables instead of placeholders.
Also, we'll be able to use this later to collect diagnostics.
- implement argument position impl trait by lowering it to type parameters.
I've realized that this is necessary to correctly implement it; e.g. consider
`fn foo(impl Display) -> impl Something`. It's observable that the return
type of e.g. `foo(1u32)` unifies with itself, but doesn't unify with e.g.
`foo(1i32)`; so the return type needs to be parameterized by the argument
type.
This fixes a few bugs as well:
- type parameters 'losing' their name when they go through Chalk, as mentioned
above (i.e. getting `[missing name]` somewhere)
- impl trait not being considered as implementing the super traits (very
noticeable for the `db` in RA)
- the fact that argument impl trait was only turned into variables when the
function got called caused type mismatches when the function was used as a
value (fixes a few type mismatches in RA)
The one thing I'm not so happy with here is how we're lowering `impl Trait` types to variables; since `TypeRef`s don't have an identity currently, we just count how many of them we have seen while going through the function signature. That's quite fragile though, since we have to do it while desugaring generics and while lowering the type signature, and in the exact same order in both cases. We could consider either giving only `TypeRef::ImplTrait` a local id, or maybe just giving all `TypeRef`s an identity after all (we talked about this before)...
Follow-up tasks:
- handle return position impl trait; we basically need to create a variable and some trait obligations for that variable
- rename `Param` to `Placeholder`
Co-authored-by: Florian Diebold <florian.diebold@freiheit.com>
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
This change:
- introduces `compute_crate_def_map` query and renames
`CrateDefMap::crate_def_map_query` for consistency,
- annotates `crate_def_map` as `salsa::transparent` and adds a
top-level `crate_def_map` wrapper function around that starts the
profiler and immediately calls into `compute_crate_def_map` query.
This allows us to better understand where we spent the time, in
particular, how much is spent in the recomputaiton and how much in
salsa.
Example output (where we don't actually re-compute anything, but the
query still takes a non-trivial amount of time):
```
211ms - handle_inlay_hints
150ms - get_inlay_hints
150ms - SourceAnalyzer::new
65ms - def_with_body_from_child_node
65ms - analyze_container
65ms - analyze_container
65ms - Module::from_definition
65ms - Module::from_file
65ms - crate_def_map
1ms - parse_macro_query (6 calls)
0ms - raw_items_query (1 calls)
64ms - ???
```
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>
2562: Fix NavigationTarget ranges r=matklad a=edwin0cheng
Fix the issue described in https://github.com/rust-analyzer/rust-analyzer/pull/2544#issuecomment-565572553
This PR change the order for finding `full_range` of `focus_range` in following orders:
1. map both ranges to macro_call
2. map focus range to a token inside macro call, and full range to the whole of macro call
3. map both ranges to the whole of macro call
And fix the corresponding tests and make these tests easily to follow.
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
2489: Implement `format_args` r=flodiebold a=flodiebold
This fixes a huge amount of type mismatches (because every format call was a type mismatch so far); I also hoped to get go to def working within `format!` etc., and the test says it should, but in practice it still doesn't seem to...
Also remove the `len` parameter from `Name::new_inline_ascii`, which I'm assuming was only there because of `const fn` limitations?
cc @edwin0cheng
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
SourceAnalyzer didn't work properly within expression macro expansions because
it didn't find the enclosing function. Fix this by going up the expansion chain
to find ancestors. This makes the test work, but apparently in real usage it's
still not working.
2479: Add expansion infrastructure for derive macros r=matklad a=flodiebold
I thought I'd experiment a bit with attribute macro/derive expansion, and here's what I've got so far. It has dummy implementations of the Copy / Clone derives, to show that the approach works; it doesn't add any attribute macro support, but I think that fits into the architecture.
Basically, during raw item collection, we look at the attributes and generate macro calls for them if necessary. Currently I only do this for derives, and just add the derive macro calls as separate calls next to the item. I think for derives, it's important that they don't obscure the actual item, since they can't actually change it (e.g. sending the item token tree through macro expansion unnecessarily might make completion within it more complicated).
Attribute macros would have to be recognized at that stage and replace the item (i.e., the raw item collector will just emit an attribute macro call, and not the item). I think when we implement this, we should try to recognize known inert attributes, so that we don't do macro expansion unnecessarily; anything that isn't known needs to be treated as a possible attribute macro call (since the raw item collector can't resolve the macro yet).
There's basically no name resolution for attribute macros implemented, I just hardcoded the built-in derives. In the future, the built-ins should work within the normal name resolution infrastructure; the problem there is that the builtin stubs in `std` use macros 2.0, which we don't support yet (and adding support is outside the scope of this).
One aspect that I don't really have a solution for, but I don't know how important it is, is removing the attribute itself from its input. I'm pretty sure rustc leaves out the attribute macro from the input, but to do that, we'd have to create a completely new syntax node. I guess we could do it when / after converting to a token tree.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
