Auto merge of #51727 - varkor:expragain-to-exprcontinue, r=petrochenkov

Rename hir::ExprAgain to hir::ExprContinue

The current name is confusing and historical.

I also used this PR to clean up the annoying indentation in `check/mod.rs`. If that's viewed as too tangential a change, I'll split it up, but it seemed reasonable to slip it in to reduce @bors's work. It's easy to compare for the two commits individually.

r? @petrochenkov

src/librustc/cfg/construct.rs

@@ -335,7 +335,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
                 self.add_unreachable_node()
             }
 
-            hir::ExprAgain(destination) => {
+            hir::ExprContinue(destination) => {
                 let (target_scope, cont_dest) =
                     self.find_scope_edge(expr, destination, ScopeCfKind::Continue);
                 let a = self.add_ast_node(expr.hir_id.local_id, &[pred]);

src/librustc/hir/intravisit.rs

@@ -1068,7 +1068,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
             }
             walk_list!(visitor, visit_expr, opt_expr);
         }
-        ExprAgain(ref destination) => {
+        ExprContinue(ref destination) => {
             if let Some(ref label) = destination.label {
                 visitor.visit_label(label);
                 match destination.target_id {

src/librustc/hir/lowering.rs

@@ -3731,7 +3731,7 @@ impl<'a> LoweringContext<'a> {
                 )
             }
             ExprKind::Continue(opt_label) => {
-                hir::ExprAgain(if self.is_in_loop_condition && opt_label.is_none() {
+                hir::ExprContinue(if self.is_in_loop_condition && opt_label.is_none() {
                     hir::Destination {
                         label: None,
                         target_id: Err(hir::LoopIdError::UnlabeledCfInWhileCondition).into(),

src/librustc/hir/mod.rs

@@ -1279,7 +1279,7 @@ impl Expr {
             ExprPath(..) => ExprPrecedence::Path,
             ExprAddrOf(..) => ExprPrecedence::AddrOf,
             ExprBreak(..) => ExprPrecedence::Break,
-            ExprAgain(..) => ExprPrecedence::Continue,
+            ExprContinue(..) => ExprPrecedence::Continue,
             ExprRet(..) => ExprPrecedence::Ret,
             ExprInlineAsm(..) => ExprPrecedence::InlineAsm,
             ExprStruct(..) => ExprPrecedence::Struct,
@@ -1374,7 +1374,7 @@ pub enum Expr_ {
     /// A `break`, with an optional label to break
     ExprBreak(Destination, Option<P<Expr>>),
     /// A `continue`, with an optional label
-    ExprAgain(Destination),
+    ExprContinue(Destination),
     /// A `return`, with an optional value to be returned
     ExprRet(Option<P<Expr>>),
 

src/librustc/hir/print.rs

@@ -1475,7 +1475,7 @@ impl<'a> State<'a> {
                     self.s.space()?;
                 }
             }
-            hir::ExprAgain(destination) => {
+            hir::ExprContinue(destination) => {
                 self.s.word("continue")?;
                 self.s.space()?;
                 if let Some(label) = destination.label {

src/librustc/ich/impls_hir.rs

@@ -621,7 +621,7 @@ impl_stable_hash_for!(enum hir::Expr_ {
     ExprPath(path),
     ExprAddrOf(mutability, sub),
     ExprBreak(destination, sub),
-    ExprAgain(destination),
+    ExprContinue(destination),
     ExprRet(val),
     ExprInlineAsm(asm, inputs, outputs),
     ExprStruct(path, fields, base),

src/librustc/middle/expr_use_visitor.rs

@@ -479,7 +479,7 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
                 self.consume_exprs(inputs);
             }
 
-            hir::ExprAgain(..) |
+            hir::ExprContinue(..) |
             hir::ExprLit(..) => {}
 
             hir::ExprLoop(ref blk, _, _) => {

src/librustc/middle/liveness.rs

@@ -502,7 +502,7 @@ fn visit_expr<'a, 'tcx>(ir: &mut IrMaps<'a, 'tcx>, expr: &'tcx Expr) {
       hir::ExprArray(..) | hir::ExprCall(..) | hir::ExprMethodCall(..) |
       hir::ExprTup(..) | hir::ExprBinary(..) | hir::ExprAddrOf(..) |
       hir::ExprCast(..) | hir::ExprUnary(..) | hir::ExprBreak(..) |
-      hir::ExprAgain(_) | hir::ExprLit(_) | hir::ExprRet(..) |
+      hir::ExprContinue(_) | hir::ExprLit(_) | hir::ExprRet(..) |
       hir::ExprBlock(..) | hir::ExprAssign(..) | hir::ExprAssignOp(..) |
       hir::ExprStruct(..) | hir::ExprRepeat(..) |
       hir::ExprInlineAsm(..) | hir::ExprBox(..) | hir::ExprYield(..) |
@@ -1047,7 +1047,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
               }
           }
 
-          hir::ExprAgain(label) => {
+          hir::ExprContinue(label) => {
               // Find which label this expr continues to
               let sc = match label.target_id {
                     Ok(node_id) => node_id,
@@ -1431,7 +1431,7 @@ fn check_expr<'a, 'tcx>(this: &mut Liveness<'a, 'tcx>, expr: &'tcx Expr) {
       hir::ExprIndex(..) | hir::ExprField(..) |
       hir::ExprArray(..) | hir::ExprTup(..) | hir::ExprBinary(..) |
       hir::ExprCast(..) | hir::ExprUnary(..) | hir::ExprRet(..) |
-      hir::ExprBreak(..) | hir::ExprAgain(..) | hir::ExprLit(_) |
+      hir::ExprBreak(..) | hir::ExprContinue(..) | hir::ExprLit(_) |
       hir::ExprBlock(..) | hir::ExprAddrOf(..) |
       hir::ExprStruct(..) | hir::ExprRepeat(..) |
       hir::ExprClosure(..) | hir::ExprPath(_) | hir::ExprYield(..) |

src/librustc/middle/mem_categorization.rs

@@ -686,7 +686,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
           hir::ExprBinary(..) | hir::ExprWhile(..) |
           hir::ExprBlock(..) | hir::ExprLoop(..) | hir::ExprMatch(..) |
           hir::ExprLit(..) | hir::ExprBreak(..) |
-          hir::ExprAgain(..) | hir::ExprStruct(..) | hir::ExprRepeat(..) |
+          hir::ExprContinue(..) | hir::ExprStruct(..) | hir::ExprRepeat(..) |
           hir::ExprInlineAsm(..) | hir::ExprBox(..) => {
             Ok(self.cat_rvalue_node(expr.id(), expr.span(), expr_ty))
           }

src/librustc_mir/hair/cx/expr.rs

@@ -543,7 +543,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                 Err(err) => bug!("invalid loop id for break: {}", err)
             }
         }
-        hir::ExprAgain(dest) => {
+        hir::ExprContinue(dest) => {
             match dest.target_id {
                 Ok(loop_id) => ExprKind::Continue {
                     label: region::Scope::Node(cx.tcx.hir.node_to_hir_id(loop_id).local_id),

src/librustc_passes/loops.rs

@@ -148,7 +148,7 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
 
                 self.require_break_cx("break", e.span);
             }
-            hir::ExprAgain(label) => {
+            hir::ExprContinue(label) => {
                 self.require_label_in_labeled_block(e.span, &label, "continue");
 
                 match label.target_id {

src/librustc_passes/rvalue_promotion.rs

@@ -469,7 +469,7 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>, e: &hir::Expr, node
 
         // More control flow (also not very meaningful).
         hir::ExprBreak(..) |
-        hir::ExprAgain(_) |
+        hir::ExprContinue(_) |
         hir::ExprRet(_) |
 
         // Generator expressions