Auto merge of #122190 - matthiaskrgr:rollup-9ol4y30, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #121025 (add known-bug tests for derive failure to detect packed repr)
 - #121194 (Refactor pre-getopts command line argument handling)
 - #121563 (Use `ControlFlow` in visitors.)
 - #122173 (Don't ICE in CTFE if raw/fn-ptr types differ)
 - #122175 (Bless tidy issues order)
 - #122179 (rustc: Fix typo)
 - #122181 (Fix crash in internal late lint checking)
 - #122183 (interpret: update comment about read_discriminant on uninhabited variants)

Failed merges:

 - #122076 (Tweak the way we protect in-place function arguments in interpreters)
 - #122132 (Diagnostic renaming 3)

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 30 insertions, 47 deletions

diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
index c327e591f3c..ebc9f1d109e 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -1,6 +1,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 
+use core::ops::ControlFlow;
 use hir::ExprKind;
 use rustc_errors::{Applicability, Diag};
 use rustc_hir as hir;
@@ -727,30 +728,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             _ => local_decl.source_info.span,
         };
 
-        struct BindingFinder {
-            span: Span,
-            hir_id: Option<hir::HirId>,
-        }
-
-        impl<'tcx> Visitor<'tcx> for BindingFinder {
-            fn visit_stmt(&mut self, s: &'tcx hir::Stmt<'tcx>) {
-                if let hir::StmtKind::Local(local) = s.kind {
-                    if local.pat.span == self.span {
-                        self.hir_id = Some(local.hir_id);
-                    }
-                }
-                hir::intravisit::walk_stmt(self, s);
-            }
-        }
-
         let def_id = self.body.source.def_id();
         let hir_id = if let Some(local_def_id) = def_id.as_local()
             && let Some(body_id) = self.infcx.tcx.hir().maybe_body_owned_by(local_def_id)
         {
             let body = self.infcx.tcx.hir().body(body_id);
-            let mut v = BindingFinder { span: pat_span, hir_id: None };
-            v.visit_body(body);
-            v.hir_id
+            BindingFinder { span: pat_span }.visit_body(body).break_value()
         } else {
             None
         };
@@ -859,17 +842,18 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         };
 
         let hir_map = self.infcx.tcx.hir();
-        struct Finder<'tcx> {
+        struct Finder {
             span: Span,
-            expr: Option<&'tcx Expr<'tcx>>,
         }
 
-        impl<'tcx> Visitor<'tcx> for Finder<'tcx> {
-            fn visit_expr(&mut self, e: &'tcx hir::Expr<'tcx>) {
-                if e.span == self.span && self.expr.is_none() {
-                    self.expr = Some(e);
+        impl<'tcx> Visitor<'tcx> for Finder {
+            type Result = ControlFlow<&'tcx Expr<'tcx>>;
+            fn visit_expr(&mut self, e: &'tcx hir::Expr<'tcx>) -> Self::Result {
+                if e.span == self.span {
+                    ControlFlow::Break(e)
+                } else {
+                    hir::intravisit::walk_expr(self, e)
                 }
-                hir::intravisit::walk_expr(self, e);
             }
         }
         if let Some(body_id) = hir_map.maybe_body_owned_by(self.mir_def_id())
@@ -878,9 +862,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             // `span` corresponds to the expression being iterated, find the `for`-loop desugared
             // expression with that span in order to identify potential fixes when encountering a
             // read-only iterator that should be mutable.
-            let mut v = Finder { span, expr: None };
-            v.visit_block(block);
-            if let Some(expr) = v.expr
+            if let ControlFlow::Break(expr) = (Finder { span }).visit_block(block)
                 && let Call(_, [expr]) = expr.kind
             {
                 match expr.kind {
@@ -1179,29 +1161,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 );
             }
             Some((false, err_label_span, message)) => {
-                struct BindingFinder {
-                    span: Span,
-                    hir_id: Option<hir::HirId>,
-                }
-
-                impl<'tcx> Visitor<'tcx> for BindingFinder {
-                    fn visit_stmt(&mut self, s: &'tcx hir::Stmt<'tcx>) {
-                        if let hir::StmtKind::Local(local) = s.kind {
-                            if local.pat.span == self.span {
-                                self.hir_id = Some(local.hir_id);
-                            }
-                        }
-                        hir::intravisit::walk_stmt(self, s);
-                    }
-                }
                 let def_id = self.body.source.def_id();
                 let hir_id = if let Some(local_def_id) = def_id.as_local()
                     && let Some(body_id) = self.infcx.tcx.hir().maybe_body_owned_by(local_def_id)
                 {
                     let body = self.infcx.tcx.hir().body(body_id);
-                    let mut v = BindingFinder { span: err_label_span, hir_id: None };
-                    v.visit_body(body);
-                    v.hir_id
+                    BindingFinder { span: err_label_span }.visit_body(body).break_value()
                 } else {
                     None
                 };
@@ -1333,6 +1298,23 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     }
 }
 
+struct BindingFinder {
+    span: Span,
+}
+
+impl<'tcx> Visitor<'tcx> for BindingFinder {
+    type Result = ControlFlow<hir::HirId>;
+    fn visit_stmt(&mut self, s: &'tcx hir::Stmt<'tcx>) -> Self::Result {
+        if let hir::StmtKind::Local(local) = s.kind
+            && local.pat.span == self.span
+        {
+            ControlFlow::Break(local.hir_id)
+        } else {
+            hir::intravisit::walk_stmt(self, s)
+        }
+    }
+}
+
 pub fn mut_borrow_of_mutable_ref(local_decl: &LocalDecl<'_>, local_name: Option<Symbol>) -> bool {
     debug!("local_info: {:?}, ty.kind(): {:?}", local_decl.local_info, local_decl.ty.kind());
 
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 5dc10308a34..8dcfe014b65 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(assert_matches)]
 #![feature(associated_type_bounds)]
 #![feature(box_patterns)]
+#![feature(control_flow_enum)]
 #![feature(let_chains)]
 #![feature(min_specialization)]
 #![feature(never_type)]