or-patterns: use top_pats_hack to make things compile.

src/librustc/hir/intravisit.rs

@@ -1103,7 +1103,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
 
 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
     visitor.visit_id(arm.hir_id);
-    walk_list!(visitor, visit_pat, &arm.pats);
+    visitor.visit_pat(&arm.pat);
     if let Some(ref g) = arm.guard {
         match g {
             Guard::If(ref e) => visitor.visit_expr(e),

src/librustc/hir/pat_util.rs

@@ -170,7 +170,7 @@ impl hir::Arm {
         // for #42640 (default match binding modes).
         //
         // See #44848.
-        self.pats.iter()
+        self.top_pats_hack().iter()
                  .filter_map(|pat| pat.contains_explicit_ref_binding())
                  .max_by_key(|m| match *m {
                     hir::MutMutable => 1,

src/librustc/middle/dead.rs

@@ -259,8 +259,9 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> {
     }
 
     fn visit_arm(&mut self, arm: &'tcx hir::Arm) {
-        if arm.pats.len() == 1 {
-            let variants = arm.pats[0].necessary_variants();
+        let pats = arm.top_pats_hack();
+        if pats.len() == 1 {
+            let variants = pats[0].necessary_variants();
 
             // Inside the body, ignore constructions of variants
             // necessary for the pattern to match. Those construction sites

src/librustc/middle/expr_use_visitor.rs

@@ -779,14 +779,14 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
 
     fn arm_move_mode(&mut self, discr_cmt: mc::cmt<'tcx>, arm: &hir::Arm) -> TrackMatchMode {
         let mut mode = Unknown;
-        for pat in &arm.pats {
+        for pat in arm.top_pats_hack() {
             self.determine_pat_move_mode(discr_cmt.clone(), &pat, &mut mode);
         }
         mode
     }
 
     fn walk_arm(&mut self, discr_cmt: mc::cmt<'tcx>, arm: &hir::Arm, mode: MatchMode) {
-        for pat in &arm.pats {
+        for pat in arm.top_pats_hack() {
             self.walk_pat(discr_cmt.clone(), &pat, mode);
         }
 

src/librustc/middle/liveness.rs

@@ -456,7 +456,7 @@ fn visit_local<'tcx>(ir: &mut IrMaps<'tcx>, local: &'tcx hir::Local) {
 }
 
 fn visit_arm<'tcx>(ir: &mut IrMaps<'tcx>, arm: &'tcx hir::Arm) {
-    for pat in &arm.pats {
+    for pat in arm.top_pats_hack() {
         add_from_pat(ir, pat);
     }
     intravisit::walk_arm(ir, arm);
@@ -1080,7 +1080,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                     // the same bindings, and we also consider the first pattern to be
                     // the "authoritative" set of ids
                     let arm_succ =
-                        self.define_bindings_in_arm_pats(arm.pats.first().map(|p| &**p),
+                        self.define_bindings_in_arm_pats(arm.top_pats_hack().first().map(|p| &**p),
                                                          guard_succ);
                     self.merge_from_succ(ln, arm_succ, first_merge);
                     first_merge = false;
@@ -1422,7 +1422,7 @@ fn check_arm<'a, 'tcx>(this: &mut Liveness<'a, 'tcx>, arm: &'tcx hir::Arm) {
     // patterns so the suggestions to prefix with underscores will apply to those too.
     let mut vars: BTreeMap<String, (LiveNode, Variable, HirId, Vec<Span>)> = Default::default();
 
-    for pat in &arm.pats {
+    for pat in arm.top_pats_hack() {
         this.arm_pats_bindings(Some(&*pat), |this, ln, var, sp, id| {
             let name = this.ir.variable_name(var);
             vars.entry(name)

src/librustc_ast_borrowck/cfg/construct.rs

@@ -390,7 +390,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
             // patterns and the guard (if there is one) in the arm.
             let bindings_exit = self.add_dummy_node(&[]);
 
-            for pat in &arm.pats {
+            for pat in arm.top_pats_hack() {
                 // Visit the pattern, coming from the discriminant exit
                 let mut pat_exit = self.pat(&pat, discr_exit);
 

src/librustc_mir/hair/cx/expr.rs

@@ -862,7 +862,7 @@ impl ToBorrowKind for hir::Mutability {
 
 fn convert_arm<'a, 'tcx>(cx: &mut Cx<'a, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
     Arm {
-        patterns: arm.pats.iter().map(|p| cx.pattern_from_hir(p)).collect(),
+        patterns: arm.top_pats_hack().iter().map(|p| cx.pattern_from_hir(p)).collect(),
         guard: match arm.guard {
                 Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
                 _ => None,

src/librustc_mir/hair/pattern/check_match.rs

@@ -137,7 +137,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
     ) {
         for arm in arms {
             // First, check legality of move bindings.
-            self.check_patterns(arm.guard.is_some(), &arm.pats);
+            self.check_patterns(arm.guard.is_some(), &arm.top_pats_hack());
 
             // Second, if there is a guard on each arm, make sure it isn't
             // assigning or borrowing anything mutably.
@@ -146,7 +146,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
             }
 
             // Third, perform some lints.
-            for pat in &arm.pats {
+            for pat in arm.top_pats_hack() {
                 check_for_bindings_named_same_as_variants(self, pat);
             }
         }
@@ -156,7 +156,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
             let mut have_errors = false;
 
             let inlined_arms : Vec<(Vec<_>, _)> = arms.iter().map(|arm| (
-                arm.pats.iter().map(|pat| {
+                arm.top_pats_hack().iter().map(|pat| {
                     let mut patcx = PatternContext::new(self.tcx,
                                                         self.param_env.and(self.identity_substs),
                                                         self.tables);

src/librustc_passes/rvalue_promotion.rs

@@ -503,7 +503,7 @@ fn check_expr_kind<'a, 'tcx>(
             // Compute the most demanding borrow from all the arms'
             // patterns and set that on the discriminator.
             let mut mut_borrow = false;
-            for pat in hirvec_arm.iter().flat_map(|arm| &arm.pats) {
+            for pat in hirvec_arm.iter().flat_map(|arm| arm.top_pats_hack()) {
                 mut_borrow = v.remove_mut_rvalue_borrow(pat);
             }
             if mut_borrow {

src/librustc_typeck/check/_match.rs

@@ -58,11 +58,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // collection into `Vec`), so we get types for all bindings.
         let all_arm_pats_diverge: Vec<_> = arms.iter().map(|arm| {
             let mut all_pats_diverge = Diverges::WarnedAlways;
-            for p in &arm.pats {
-                self.diverges.set(Diverges::Maybe);
-                self.check_pat_top(&p, discrim_ty, Some(discrim.span));
-                all_pats_diverge &= self.diverges.get();
-            }
+            self.diverges.set(Diverges::Maybe);
+            self.check_pat_top(&arm.pat, discrim_ty, Some(discrim.span));
+            all_pats_diverge &= self.diverges.get();
 
             // As discussed with @eddyb, this is for disabling unreachable_code
             // warnings on patterns (they're now subsumed by unreachable_patterns

src/librustc_typeck/check/regionck.rs

@@ -488,7 +488,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RegionCtxt<'a, 'tcx> {
 
     fn visit_arm(&mut self, arm: &'tcx hir::Arm) {
         // see above
-        for p in &arm.pats {
+        for p in arm.top_pats_hack() {
             self.constrain_bindings_in_pat(p);
         }
         intravisit::walk_arm(self, arm);
@@ -1069,7 +1069,7 @@ impl<'a, 'tcx> RegionCtxt<'a, 'tcx> {
         let discr_cmt = Rc::new(ignore_err!(self.with_mc(|mc| mc.cat_expr(discr))));
         debug!("discr_cmt={:?}", discr_cmt);
         for arm in arms {
-            for root_pat in &arm.pats {
+            for root_pat in arm.top_pats_hack() {
                 self.link_pattern(discr_cmt.clone(), &root_pat);
             }
         }