From 3cfcd4ed962ffede6dc1405f26c34ac4b9c2462c Mon Sep 17 00:00:00 2001
From: Nadrieril <nadrieril+git@gmail.com>
Date: Sun, 17 Mar 2024 16:33:25 +0100
Subject: [PATCH] Abstract over the uses of `compute_match_usefulness`

---
 crates/hir-ty/src/diagnostics/expr.rs           | 17 ++---------------
 .../src/diagnostics/match_check/pat_analysis.rs |  9 +++++++++
 2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/crates/hir-ty/src/diagnostics/expr.rs b/crates/hir-ty/src/diagnostics/expr.rs
index b3128712dc..20b0da441d 100644
--- a/crates/hir-ty/src/diagnostics/expr.rs
+++ b/crates/hir-ty/src/diagnostics/expr.rs
@@ -11,7 +11,6 @@ use hir_def::{ItemContainerId, Lookup};
 use hir_expand::name;
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
-use rustc_pattern_analysis::usefulness::{compute_match_usefulness, PlaceValidity};
 use syntax::{ast, AstNode};
 use tracing::debug;
 use triomphe::Arc;
@@ -234,13 +233,7 @@ impl ExprValidator {
             return;
         }
 
-        let report = match compute_match_usefulness(
-            &cx,
-            m_arms.as_slice(),
-            scrut_ty.clone(),
-            PlaceValidity::ValidOnly,
-            None,
-        ) {
+        let report = match cx.compute_match_usefulness(m_arms.as_slice(), scrut_ty.clone()) {
             Ok(report) => report,
             Err(()) => return,
         };
@@ -282,13 +275,7 @@ impl ExprValidator {
                 continue;
             }
 
-            let report = match compute_match_usefulness(
-                &cx,
-                &[match_arm],
-                ty.clone(),
-                PlaceValidity::ValidOnly,
-                None,
-            ) {
+            let report = match cx.compute_match_usefulness(&[match_arm], ty.clone()) {
                 Ok(v) => v,
                 Err(e) => {
                     debug!(?e, "match usefulness error");
diff --git a/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs b/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs
index 81ce51429c..82b80a53e3 100644
--- a/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs
+++ b/crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs
@@ -8,6 +8,7 @@ use rustc_hash::FxHashMap;
 use rustc_pattern_analysis::{
     constructor::{Constructor, ConstructorSet, VariantVisibility},
     index::IdxContainer,
+    usefulness::{compute_match_usefulness, PlaceValidity, UsefulnessReport},
     Captures, PatCx, PrivateUninhabitedField,
 };
 use smallvec::{smallvec, SmallVec};
@@ -59,6 +60,14 @@ impl<'p> MatchCheckCtx<'p> {
         Self { module, body, db, exhaustive_patterns, min_exhaustive_patterns }
     }
 
+    pub(crate) fn compute_match_usefulness(
+        &self,
+        arms: &[MatchArm<'p>],
+        scrut_ty: Ty,
+    ) -> Result<UsefulnessReport<'p, Self>, ()> {
+        compute_match_usefulness(self, arms, scrut_ty, PlaceValidity::ValidOnly, None)
+    }
+
     fn is_uninhabited(&self, ty: &Ty) -> bool {
         is_ty_uninhabited_from(ty, self.module, self.db)
     }