language-servers/rust-analyzer
1
0
Fork 0
mirror of https://github.com/rust-lang/rust-analyzer.git synced 2025-10-03 07:04:49 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Properly infer types with type casts

Browse source
This commit is contained in:
Ryo Yoshida 2023-07-12 23:46:23 +09:00
parent 75ac37f317
commit 074488b290
No known key found for this signature in database
GPG key ID: E25698A930586171
5 changed files with 112 additions and 28 deletions
Download patch file Download diff file Expand all files Collapse all files

34
crates/hir-ty/src/infer.rs
View file

@ -13,6 +13,15 @@
//! to certain types. To record this, we use the union-find implementation from
//! the `ena` crate, which is extracted from rustc.
mod cast;
pub(crate) mod closure;
mod coerce;
mod expr;
mod mutability;
mod pat;
mod path;
pub(crate) mod unify;
use std::{convert::identity, ops::Index};
use chalk_ir::{
@ -60,15 +69,8 @@ pub use coerce::could_coerce;
#[allow(unreachable_pub)]
pub use unify::could_unify;
pub(crate) use self::closure::{CaptureKind, CapturedItem, CapturedItemWithoutTy};
pub(crate) mod unify;
mod path;
mod expr;
mod pat;
mod coerce;
pub(crate) mod closure;
mod mutability;
use cast::CastCheck;
pub(crate) use closure::{CaptureKind, CapturedItem, CapturedItemWithoutTy};
/// The entry point of type inference.
pub(crate) fn infer_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
@ -508,6 +510,8 @@ pub(crate) struct InferenceContext<'a> {
diverges: Diverges,
breakables: Vec<BreakableContext>,
deferred_cast_checks: Vec<CastCheck>,
// fields related to closure capture
current_captures: Vec<CapturedItemWithoutTy>,
current_closure: Option<ClosureId>,
@ -582,7 +586,8 @@ impl<'a> InferenceContext<'a> {
resolver,
diverges: Diverges::Maybe,
breakables: Vec::new(),
current_captures: vec![],
deferred_cast_checks: Vec::new(),
current_captures: Vec::new(),
current_closure: None,
deferred_closures: FxHashMap::default(),
closure_dependencies: FxHashMap::default(),
@ -594,7 +599,7 @@ impl<'a> InferenceContext<'a> {
// used this function for another workaround, mention it here. If you really need this function and believe that
// there is no problem in it being `pub(crate)`, remove this comment.
pub(crate) fn resolve_all(self) -> InferenceResult {
let InferenceContext { mut table, mut result, .. } = self;
let InferenceContext { mut table, mut result, deferred_cast_checks, .. } = self;
// Destructure every single field so whenever new fields are added to `InferenceResult` we
// don't forget to handle them here.
let InferenceResult {
@ -622,6 +627,13 @@ impl<'a> InferenceContext<'a> {
table.fallback_if_possible();
// Comment from rustc:
// Even though coercion casts provide type hints, we check casts after fallback for
// backwards compatibility. This makes fallback a stronger type hint than a cast coercion.
for cast in deferred_cast_checks {
cast.check(&mut table);
}
// FIXME resolve obligations as well (use Guidance if necessary)
table.resolve_obligations_as_possible();