diff --git a/compiler/rustc_hir_analysis/src/check/compare_method.rs b/compiler/rustc_hir_analysis/src/check/compare_method.rs
index 3469ec4767b7c..b844ecfdf1877 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_method.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_method.rs
@@ -403,6 +403,7 @@ fn compare_predicate_entailment<'tcx>(
terr,
false,
false,
+ false,
);
return Err(diag.emit());
@@ -516,6 +517,7 @@ pub fn collect_trait_impl_trait_tys<'tcx>(
terr,
false,
false,
+ false,
);
return Err(diag.emit());
}
@@ -1425,6 +1427,7 @@ pub(crate) fn raw_compare_const_impl<'tcx>(
terr,
false,
false,
+ false,
);
return Err(diag.emit());
};
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 08a3cbccfb05e..7a47e8be74a2e 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -846,6 +846,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
e,
false,
true,
+ false,
);
}
}
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 9ff703e521ff6..fd7a06fccbfb0 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -1,3 +1,4 @@
+// ignore-tidy-filelength
//! Error Reporting Code for the inference engine
//!
//! Because of the way inference, and in particular region inference,
@@ -64,8 +65,12 @@ use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString, Mul
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::intravisit::walk_block;
+use rustc_hir::intravisit::walk_expr;
+use rustc_hir::intravisit::Visitor;
use rustc_hir::lang_items::LangItem;
-use rustc_hir::Node;
+use rustc_hir::HirId;
+use rustc_hir::{Expr, Node};
use rustc_middle::dep_graph::DepContext;
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::relate::{self, RelateResult, TypeRelation};
@@ -620,12 +625,55 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
}
+ fn note_enum_suggestion(
+ &self,
+ err: &mut Diagnostic,
+ span: Span,
+ body_id: HirId,
+ arg_size: usize,
+ ) {
+ let body_node = self.tcx.hir().get(body_id);
+ let hir::Node::Expr(&hir::Expr{kind:hir::ExprKind::Block(body_expr, ..), ..}) = body_node else {return ()};
+ struct FindExprVisitor<'tcx> {
+ target_span: Span,
+ size: usize,
+ terr: &'tcx mut Diagnostic,
+ }
+ impl<'tcx> Visitor<'tcx> for FindExprVisitor<'tcx> {
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if expr.span == self.target_span {
+ let mut suggest_vec = vec![];
+ let mut i = 0;
+ suggest_vec.push((expr.span.shrink_to_hi(), "(".to_string()));
+ while i < self.size {
+ suggest_vec.push((expr.span.shrink_to_hi(), "_".to_string()));
+ if i != self.size - 1 {
+ suggest_vec.push((expr.span.shrink_to_hi(), ",".to_string()));
+ }
+ i = i + 1;
+ }
+ suggest_vec.push((expr.span.shrink_to_hi(), ")".to_string()));
+
+ self.terr.multipart_suggestion(
+ "use parentheses to instantiate this tuple variant",
+ suggest_vec,
+ Applicability::MachineApplicable,
+ );
+ }
+ walk_expr(self, expr);
+ }
+ }
+ let mut visitor = FindExprVisitor { target_span: span, size: arg_size, terr: err };
+ walk_block(&mut visitor, body_expr);
+ }
+
fn note_error_origin(
&self,
err: &mut Diagnostic,
cause: &ObligationCause<'tcx>,
exp_found: Option<ty::error::ExpectedFound<Ty<'tcx>>>,
terr: TypeError<'tcx>,
+ detect_enum_noparm: bool,
) {
match *cause.code() {
ObligationCauseCode::Pattern { origin_expr: true, span: Some(span), root_ty } => {
@@ -639,8 +687,14 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
{
err.span_label(span, format!("this is an iterator with items of type `{}`", substs.type_at(0)));
} else {
- err.span_label(span, format!("this expression has type `{}`", ty));
- }
+ err.span_label(span, format!("this expression has type `{}`", ty));
+ if detect_enum_noparm &&
+ let ty::FnDef(def_id, substs) = ty.kind(){
+ let sig = self.tcx.bound_fn_sig(*def_id).subst(self.tcx, substs);
+ let sig = self.tcx.erase_late_bound_regions(sig);
+ self.note_enum_suggestion(err, span, cause.body_id, sig.inputs().len());
+ }
+ }
}
if let Some(ty::error::ExpectedFound { found, .. }) = exp_found
&& ty.is_box() && ty.boxed_ty() == found
@@ -1489,6 +1543,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
terr: TypeError<'tcx>,
swap_secondary_and_primary: bool,
prefer_label: bool,
+ detect_enum_noparm: bool,
) {
let span = cause.span();
@@ -1939,7 +1994,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
// It reads better to have the error origin as the final
// thing.
- self.note_error_origin(diag, cause, exp_found, terr);
+ self.note_error_origin(diag, cause, exp_found, terr, detect_enum_noparm);
debug!(?diag);
}
@@ -2259,6 +2314,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
let span = trace.cause.span();
let failure_code = trace.cause.as_failure_code(terr);
+ let mut detect_enum_noparm = false;
let mut diag = match failure_code {
FailureCode::Error0038(did) => {
let violations = self.tcx.object_safety_violations(did);
@@ -2332,6 +2388,9 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
}
}
+ (ty::FnDef(_, _), ty::Adt(adt_id, _)) if adt_id.is_enum() => {
+ detect_enum_noparm = true;
+ }
_ => {}
}
}
@@ -2352,7 +2411,16 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
struct_span_err!(self.tcx.sess, span, E0644, "{}", failure_str)
}
};
- self.note_type_err(&mut diag, &trace.cause, None, Some(trace.values), terr, false, false);
+ self.note_type_err(
+ &mut diag,
+ &trace.cause,
+ None,
+ Some(trace.values),
+ terr,
+ false,
+ false,
+ detect_enum_noparm,
+ );
diag
}
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 1217d264a9c1a..d99beb895f37b 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -1687,6 +1687,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
err,
true,
false,
+ false,
);
self.note_obligation_cause(&mut diag, obligation);
diag.emit();
diff --git a/src/test/ui/type/issue-101208.rs b/src/test/ui/type/issue-101208.rs
new file mode 100644
index 0000000000000..49654a9e32734
--- /dev/null
+++ b/src/test/ui/type/issue-101208.rs
@@ -0,0 +1,10 @@
+enum E {
+ One(i32, i32)
+}
+fn main() {
+ let var = E::One;
+ if let E::One(var1, var2) = var {
+ //~^ ERROR 0308
+ println!("{var1} {var2}");
+ }
+}
diff --git a/src/test/ui/type/issue-101208.stderr b/src/test/ui/type/issue-101208.stderr
new file mode 100644
index 0000000000000..ae6065df2f29e
--- /dev/null
+++ b/src/test/ui/type/issue-101208.stderr
@@ -0,0 +1,18 @@
+error[E0308]: mismatched types
+ --> $DIR/issue-101208.rs:6:12
+ |
+LL | if let E::One(var1, var2) = var {
+ | ^^^^^^^^^^^^^^^^^^ --- this expression has type `fn(i32, i32) -> E {E::One}`
+ | |
+ | expected fn item, found enum `E`
+ |
+ = note: expected fn item `fn(i32, i32) -> E {E::One}`
+ found enum `E`
+help: use parentheses to instantiate this tuple variant
+ |
+LL | if let E::One(var1, var2) = var(_,_) {
+ | +
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.