Perform match checking on THIR.

compiler/rustc_mir_build/src/build/mod.rs

@@ -58,6 +58,7 @@ fn mir_build(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> Body<'_
         ty::WithOptConstParam { did, const_param_did: None } => {
             tcx.ensure_with_value().thir_check_unsafety(did);
             tcx.ensure_with_value().thir_abstract_const(did);
+            tcx.ensure_with_value().check_match(did);
         }
     }
 

compiler/rustc_mir_build/src/errors.rs

@@ -10,7 +10,8 @@ use rustc_hir::def::Res;
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::thir::Pat;
 use rustc_middle::ty::{self, Ty};
-use rustc_span::{symbol::Ident, Span};
+use rustc_span::symbol::Symbol;
+use rustc_span::Span;
 
 #[derive(LintDiagnostic)]
 #[diag(mir_build_unconditional_recursion)]
@@ -534,18 +535,10 @@ pub struct TrailingIrrefutableLetPatterns {
 #[derive(LintDiagnostic)]
 #[diag(mir_build_bindings_with_variant_name, code = "E0170")]
 pub struct BindingsWithVariantName {
-    #[suggestion(code = "{ty_path}::{ident}", applicability = "machine-applicable")]
+    #[suggestion(code = "{ty_path}::{name}", applicability = "machine-applicable")]
     pub suggestion: Option<Span>,
     pub ty_path: String,
-    pub ident: Ident,
-}
-
-#[derive(LintDiagnostic)]
-#[diag(mir_build_irrefutable_let_patterns_generic_let)]
-#[note]
-#[help]
-pub struct IrrefutableLetPatternsGenericLet {
-    pub count: usize,
+    pub name: Symbol,
 }
 
 #[derive(LintDiagnostic)]
@@ -590,7 +583,7 @@ pub struct BorrowOfMovedValue<'tcx> {
     pub binding_span: Span,
     #[label(mir_build_value_borrowed_label)]
     pub conflicts_ref: Vec<Span>,
-    pub name: Ident,
+    pub name: Symbol,
     pub ty: Ty<'tcx>,
     #[suggestion(code = "ref ", applicability = "machine-applicable")]
     pub suggest_borrowing: Option<Span>,
@@ -638,19 +631,19 @@ pub enum Conflict {
     Mut {
         #[primary_span]
         span: Span,
-        name: Ident,
+        name: Symbol,
     },
     #[label(mir_build_borrow)]
     Ref {
         #[primary_span]
         span: Span,
-        name: Ident,
+        name: Symbol,
     },
     #[label(mir_build_moved)]
     Moved {
         #[primary_span]
         span: Span,
-        name: Ident,
+        name: Symbol,
     },
 }
 

compiler/rustc_mir_build/src/thir/pattern/mod.rs

@@ -54,11 +54,9 @@ pub(super) fn pat_from_hir<'a, 'tcx>(
     pat: &'tcx hir::Pat<'tcx>,
 ) -> Box<Pat<'tcx>> {
     let mut pcx = PatCtxt::new(tcx, param_env, typeck_results);
+    pcx.include_lint_checks();
     let result = pcx.lower_pattern(pat);
-    if !pcx.errors.is_empty() {
-        let msg = format!("encountered errors lowering pattern: {:?}", pcx.errors);
-        tcx.sess.delay_span_bug(pat.span, &msg);
-    }
+    pcx.report_inlining_errors();
     debug!("pat_from_hir({:?}) = {:?}", pat, result);
     result
 }
@@ -77,6 +75,25 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         self
     }
 
+    fn report_inlining_errors(&self) {
+        for error in &self.errors {
+            match *error {
+                PatternError::StaticInPattern(span) => {
+                    self.tcx.sess.emit_err(StaticInPattern { span });
+                }
+                PatternError::AssocConstInPattern(span) => {
+                    self.tcx.sess.emit_err(AssocConstInPattern { span });
+                }
+                PatternError::ConstParamInPattern(span) => {
+                    self.tcx.sess.emit_err(ConstParamInPattern { span });
+                }
+                PatternError::NonConstPath(span) => {
+                    self.tcx.sess.emit_err(NonConstPath { span });
+                }
+            }
+        }
+    }
+
     fn lower_pattern(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> {
         // When implicit dereferences have been inserted in this pattern, the unadjusted lowered
         // pattern has the type that results *after* dereferencing. For example, in this code: