Unnamed repository; edit this file 'description' to name the repository.
-rw-r--r--crates/hir-ty/src/diagnostics/expr.rs17
-rw-r--r--crates/hir-ty/src/diagnostics/match_check/pat_analysis.rs14
-rw-r--r--crates/ide-diagnostics/src/handlers/missing_match_arms.rs27
3 files changed, 42 insertions, 16 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..f45beb4c92 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 +60,18 @@ 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>, ()> {
+ // FIXME: Determine place validity correctly. For now, err on the safe side.
+ let place_validity = PlaceValidity::MaybeInvalid;
+ // Measured to take ~100ms on modern hardware.
+ let complexity_limit = Some(500000);
+ compute_match_usefulness(self, arms, scrut_ty, place_validity, complexity_limit)
+ }
+
fn is_uninhabited(&self, ty: &Ty) -> bool {
is_ty_uninhabited_from(ty, self.module, self.db)
}
@@ -465,7 +478,6 @@ impl<'p> PatCx for MatchCheckCtx<'p> {
}
fn complexity_exceeded(&self) -> Result<(), Self::Error> {
- // FIXME(Nadrieril): make use of the complexity counter.
Err(())
}
}
diff --git a/crates/ide-diagnostics/src/handlers/missing_match_arms.rs b/crates/ide-diagnostics/src/handlers/missing_match_arms.rs
index 67daa172b2..045154614f 100644
--- a/crates/ide-diagnostics/src/handlers/missing_match_arms.rs
+++ b/crates/ide-diagnostics/src/handlers/missing_match_arms.rs
@@ -23,6 +23,7 @@ mod tests {
},
DiagnosticsConfig,
};
+ use test_utils::skip_slow_tests;
#[track_caller]
fn check_diagnostics_no_bails(ra_fixture: &str) {
@@ -1004,6 +1005,32 @@ fn f() {
);
}
+ #[test]
+ fn exponential_match() {
+ if skip_slow_tests() {
+ return;
+ }
+ // Constructs a match where match checking takes exponential time. Ensures we bail early.
+ use std::fmt::Write;
+ let struct_arity = 50;
+ let mut code = String::new();
+ write!(code, "struct BigStruct {{").unwrap();
+ for i in 0..struct_arity {
+ write!(code, " field{i}: bool,").unwrap();
+ }
+ write!(code, "}}").unwrap();
+ write!(code, "fn big_match(s: BigStruct) {{").unwrap();
+ write!(code, " match s {{").unwrap();
+ for i in 0..struct_arity {
+ write!(code, " BigStruct {{ field{i}: true, ..}} => {{}},").unwrap();
+ write!(code, " BigStruct {{ field{i}: false, ..}} => {{}},").unwrap();
+ }
+ write!(code, " _ => {{}},").unwrap();
+ write!(code, " }}").unwrap();
+ write!(code, "}}").unwrap();
+ check_diagnostics_no_bails(&code);
+ }
+
mod rust_unstable {
use super::*;