Rollup merge of rust-lang#99332 - jyn514:stabilize-label-break-value,…

… r=petrochenkov

Stabilize `#![feature(label_break_value)]`

See the stabilization report in rust-lang#48594 (comment).

compiler/rustc_ast/src/lib.rs

@@ -13,7 +13,7 @@
 #![feature(const_default_impls)]
 #![feature(const_trait_impl)]
 #![feature(if_let_guard)]
-#![feature(label_break_value)]
+#![cfg_attr(bootstrap, feature(label_break_value))]
 #![feature(min_specialization)]
 #![feature(negative_impls)]
 #![feature(slice_internals)]

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -647,14 +647,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             ast::ExprKind::TryBlock(_) => {
                 gate_feature_post!(&self, try_blocks, e.span, "`try` expression is experimental");
             }
-            ast::ExprKind::Block(_, Some(label)) => {
-                gate_feature_post!(
-                    &self,
-                    label_break_value,
-                    label.ident.span,
-                    "labels on blocks are unstable"
-                );
-            }
             _ => {}
         }
         visit::walk_expr(self, e)
@@ -823,7 +815,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session) {
     gate_all!(box_patterns, "box pattern syntax is experimental");
     gate_all!(exclusive_range_pattern, "exclusive range pattern syntax is experimental");
     gate_all!(try_blocks, "`try` blocks are unstable");
-    gate_all!(label_break_value, "labels on blocks are unstable");
     gate_all!(box_syntax, "box expression syntax is experimental; you can call `Box::new` instead");
     gate_all!(type_ascription, "type ascription is experimental");
 

compiler/rustc_error_codes/src/error_codes/E0695.md

@@ -3,7 +3,6 @@ A `break` statement without a label appeared inside a labeled block.
 Erroneous code example:
 
 ```compile_fail,E0695
-# #![feature(label_break_value)]
 loop {
     'a: {
         break;
@@ -14,7 +13,6 @@ loop {
 Make sure to always label the `break`:
 
 ```
-# #![feature(label_break_value)]
 'l: loop {
     'a: {
         break 'l;
@@ -25,7 +23,6 @@ Make sure to always label the `break`:
 Or if you want to `break` the labeled block:
 
 ```
-# #![feature(label_break_value)]
 loop {
     'a: {
         break 'a;

compiler/rustc_feature/src/accepted.rs

@@ -186,6 +186,8 @@ declare_features! (
     /// Allows some increased flexibility in the name resolution rules,
     /// especially around globs and shadowing (RFC 1560).
     (accepted, item_like_imports, "1.15.0", Some(35120), None),
+    /// Allows `'a: { break 'a; }`.
+    (accepted, label_break_value, "1.65.0", Some(48594), None),
     /// Allows `if/while p && let q = r && ...` chains.
     (accepted, let_chains, "1.64.0", Some(53667), None),
     /// Allows `break {expr}` with a value inside `loop`s.

compiler/rustc_feature/src/active.rs

@@ -420,8 +420,6 @@ declare_features! (
     (active, intra_doc_pointers, "1.51.0", Some(80896), None),
     /// Allows `#[instruction_set(_)]` attribute
     (active, isa_attribute, "1.48.0", Some(74727), None),
-    /// Allows `'a: { break 'a; }`.
-    (active, label_break_value, "1.28.0", Some(48594), None),
     // Allows setting the threshold for the `large_assignments` lint.
     (active, large_assignments, "1.52.0", Some(83518), None),
     /// Allows `let...else` statements.

compiler/rustc_infer/src/lib.rs

@@ -17,7 +17,7 @@
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(extend_one)]
-#![feature(label_break_value)]
+#![cfg_attr(bootstrap, feature(label_break_value))]
 #![feature(let_else)]
 #![feature(min_specialization)]
 #![feature(never_type)]

compiler/rustc_parse/src/parser/expr.rs

@@ -2014,10 +2014,6 @@ impl<'a> Parser<'a> {
             }
         }
 
-        if let Some(label) = opt_label {
-            self.sess.gated_spans.gate(sym::label_break_value, label.ident.span);
-        }
-
         if self.token.is_whole_block() {
             self.sess.emit_err(InvalidBlockMacroSegment {
                 span: self.token.span,

compiler/rustc_trait_selection/src/lib.rs

@@ -16,7 +16,7 @@
 #![feature(control_flow_enum)]
 #![feature(drain_filter)]
 #![feature(hash_drain_filter)]
-#![feature(label_break_value)]
+#![cfg_attr(bootstrap, feature(label_break_value))]
 #![feature(let_else)]
 #![feature(if_let_guard)]
 #![feature(never_type)]

compiler/rustc_typeck/src/lib.rs

@@ -64,7 +64,7 @@ This API is completely unstable and subject to change.
 #![feature(if_let_guard)]
 #![feature(is_sorted)]
 #![feature(iter_intersperse)]
-#![feature(label_break_value)]
+#![cfg_attr(bootstrap, feature(label_break_value))]
 #![feature(let_else)]
 #![feature(min_specialization)]
 #![feature(never_type)]

library/std/src/lib.rs

@@ -252,7 +252,7 @@
 #![feature(dropck_eyepatch)]
 #![feature(exhaustive_patterns)]
 #![feature(intra_doc_pointers)]
-#![feature(label_break_value)]
+#![cfg_attr(bootstrap, feature(label_break_value))]
 #![feature(lang_items)]
 #![feature(let_else)]
 #![feature(linkage)]

src/test/ui/for-loop-while/label_break_value.rs

@@ -1,7 +1,6 @@
 // run-pass
 #![allow(dead_code)]
 #![allow(unused_assignments)]
-#![feature(label_break_value)]
 
 // Test control flow to follow label_break_value semantics
 fn label_break(a: bool, b: bool) -> u32 {

src/test/ui/for-loop-while/label_break_value_invalid.rs

@@ -1,5 +1,4 @@
 #![crate_type = "lib"]
-#![feature(label_break_value)]
 
 fn lbv_macro_test_hygiene_respected() {
     macro_rules! mac2 {

src/test/ui/for-loop-while/label_break_value_invalid.stderr

@@ -1,5 +1,5 @@
 error[E0426]: use of undeclared label `'a`
-  --> $DIR/label_break_value_invalid.rs:7:19
+  --> $DIR/label_break_value_invalid.rs:6:19
    |
 LL |             break 'a $val;
    |                   ^^ undeclared label `'a`
@@ -10,7 +10,7 @@ LL |                 mac2!(2);
    = note: this error originates in the macro `mac2` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0426]: use of undeclared label `'a`
-  --> $DIR/label_break_value_invalid.rs:29:19
+  --> $DIR/label_break_value_invalid.rs:28:19
    |
 LL |     let x: u8 = mac3!('b: {
    |                       -- a label with a similar name is reachable
@@ -22,7 +22,7 @@ LL |             break 'a 3;
    |                   help: try using similarly named label: `'b`
 
 error[E0426]: use of undeclared label `'a`
-  --> $DIR/label_break_value_invalid.rs:34:29
+  --> $DIR/label_break_value_invalid.rs:33:29
    |
 LL |     let x: u8 = mac3!(break 'a 4);
    |                             ^^ undeclared label `'a`

src/test/ui/issues/issue-62480.rs

@@ -1,5 +1,3 @@
-#![feature(label_break_value)]
-
 fn main() {
     // This used to ICE during liveness check because `target_id` passed to
     // `propagate_through_expr` would be the closure and not the `loop`, which wouldn't be found in

src/test/ui/issues/issue-62480.stderr

@@ -1,5 +1,5 @@
 error[E0767]: use of unreachable label `'a`
-  --> $DIR/issue-62480.rs:8:18
+  --> $DIR/issue-62480.rs:6:18
    |
 LL |     'a: {
    |     -- unreachable label defined here
@@ -9,7 +9,7 @@ LL |         || break 'a
    = note: labels are unreachable through functions, closures, async blocks and modules
 
 error[E0267]: `break` inside of a closure
-  --> $DIR/issue-62480.rs:8:12
+  --> $DIR/issue-62480.rs:6:12
    |
 LL |         || break 'a
    |         -- ^^^^^^^^ cannot `break` inside of a closure

src/test/ui/label/label_break_value_continue.rs

@@ -1,4 +1,3 @@
-#![feature(label_break_value)]
 #![allow(unused_labels)]
 
 // Simple continue pointing to an unlabeled break should yield in an error

src/test/ui/label/label_break_value_continue.stderr

@@ -1,11 +1,11 @@
 error[E0695]: unlabeled `continue` inside of a labeled block
-  --> $DIR/label_break_value_continue.rs:7:9
+  --> $DIR/label_break_value_continue.rs:6:9
    |
 LL |         continue;
    |         ^^^^^^^^ `continue` statements that would diverge to or through a labeled block need to bear a label
 
 error[E0696]: `continue` pointing to a labeled block
-  --> $DIR/label_break_value_continue.rs:14:9
+  --> $DIR/label_break_value_continue.rs:13:9
    |
 LL | /     'b: {
 LL | |         continue 'b;
@@ -14,7 +14,7 @@ LL | |     }
    | |_____- labeled block the `continue` points to
 
 error[E0695]: unlabeled `continue` inside of a labeled block
-  --> $DIR/label_break_value_continue.rs:22:13
+  --> $DIR/label_break_value_continue.rs:21:13
    |
 LL |             continue;
    |             ^^^^^^^^ `continue` statements that would diverge to or through a labeled block need to bear a label

src/test/ui/label/label_break_value_desugared_break.rs

@@ -1,5 +1,5 @@
 // compile-flags: --edition 2018
-#![feature(label_break_value, try_blocks)]
+#![feature(try_blocks)]
 
 // run-pass
 fn main() {
@@ -9,4 +9,11 @@ fn main() {
             break 'foo;
         }
     };
+
+    'foo: {
+        let _: Result<(), ()> = try {
+            Err(())?;
+            break 'foo;
+        };
+    }
 }

src/test/ui/label/label_break_value_illegal_uses.fixed

@@ -1,5 +1,4 @@
 // run-rustfix
-#![feature(label_break_value)]
 
 // These are forbidden occurrences of label-break-value
 

src/test/ui/label/label_break_value_illegal_uses.rs

@@ -1,5 +1,4 @@
 // run-rustfix
-#![feature(label_break_value)]
 
 // These are forbidden occurrences of label-break-value
 

src/test/ui/label/label_break_value_illegal_uses.stderr

@@ -1,23 +1,23 @@
 error: block label not supported here
-  --> $DIR/label_break_value_illegal_uses.rs:8:12
+  --> $DIR/label_break_value_illegal_uses.rs:7:12
    |
 LL |     unsafe 'b: {}
    |            ^^^ not supported here
 
 error: block label not supported here
-  --> $DIR/label_break_value_illegal_uses.rs:12:13
+  --> $DIR/label_break_value_illegal_uses.rs:11:13
    |
 LL |     if true 'b: {}
    |             ^^^ not supported here
 
 error: block label not supported here
-  --> $DIR/label_break_value_illegal_uses.rs:16:21
+  --> $DIR/label_break_value_illegal_uses.rs:15:21
    |
 LL |     if true {} else 'b: {}
    |                     ^^^ not supported here
 
 error: block label not supported here
-  --> $DIR/label_break_value_illegal_uses.rs:20:17
+  --> $DIR/label_break_value_illegal_uses.rs:19:17
    |
 LL |     match false 'b: {
    |                 ^^^ not supported here

src/test/ui/label/label_break_value_unlabeled_break.rs

@@ -1,4 +1,3 @@
-#![feature(label_break_value)]
 #![allow(unused_labels)]
 
 // Simple unlabeled break should yield in an error

src/test/ui/label/label_break_value_unlabeled_break.stderr

@@ -1,11 +1,11 @@
 error[E0695]: unlabeled `break` inside of a labeled block
-  --> $DIR/label_break_value_unlabeled_break.rs:7:9
+  --> $DIR/label_break_value_unlabeled_break.rs:6:9
    |
 LL |         break;
    |         ^^^^^ `break` statements that would diverge to or through a labeled block need to bear a label
 
 error[E0695]: unlabeled `break` inside of a labeled block
-  --> $DIR/label_break_value_unlabeled_break.rs:15:13
+  --> $DIR/label_break_value_unlabeled_break.rs:14:13
    |
 LL |             break;
    |             ^^^^^ `break` statements that would diverge to or through a labeled block need to bear a label

src/test/ui/lint/unused_labels.rs

@@ -4,7 +4,6 @@
 
 // check-pass
 
-#![feature(label_break_value)]
 #![warn(unused_labels)]
 
 fn main() {

src/test/ui/lint/unused_labels.stderr

@@ -1,5 +1,5 @@
 warning: label name `'many_used_shadowed` shadows a label name that is already in scope
-  --> $DIR/unused_labels.rs:62:9
+  --> $DIR/unused_labels.rs:61:9
    |
 LL |     'many_used_shadowed: for _ in 0..10 {
    |     ------------------- first declared here
@@ -8,55 +8,55 @@ LL |         'many_used_shadowed: for _ in 0..10 {
    |         ^^^^^^^^^^^^^^^^^^^ label `'many_used_shadowed` already in scope
 
 warning: unused label
-  --> $DIR/unused_labels.rs:11:5
+  --> $DIR/unused_labels.rs:10:5
    |
 LL |     'unused_while_label: while 0 == 0 {
    |     ^^^^^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
-  --> $DIR/unused_labels.rs:8:9
+  --> $DIR/unused_labels.rs:7:9
    |
 LL | #![warn(unused_labels)]
    |         ^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:16:5
+  --> $DIR/unused_labels.rs:15:5
    |
 LL |     'unused_while_let_label: while let Some(_) = opt {
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:20:5
+  --> $DIR/unused_labels.rs:19:5
    |
 LL |     'unused_for_label: for _ in 0..10 {
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:36:9
+  --> $DIR/unused_labels.rs:35:9
    |
 LL |         'unused_loop_label_inner_2: for _ in 0..10 {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:42:5
+  --> $DIR/unused_labels.rs:41:5
    |
 LL |     'unused_loop_label_outer_3: for _ in 0..10 {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:60:5
+  --> $DIR/unused_labels.rs:59:5
    |
 LL |     'many_used_shadowed: for _ in 0..10 {
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:72:5
+  --> $DIR/unused_labels.rs:71:5
    |
 LL |     'unused_loop_label: loop {
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused label
-  --> $DIR/unused_labels.rs:78:5
+  --> $DIR/unused_labels.rs:77:5
    |
 LL |     'unused_block_label: {
    |     ^^^^^^^^^^^^^^^^^^^

src/test/ui/macros/stringify.rs

@@ -9,7 +9,6 @@
 #![feature(decl_macro)]
 #![feature(generators)]
 #![feature(half_open_range_patterns)]
-#![feature(label_break_value)]
 #![feature(more_qualified_paths)]
 #![feature(raw_ref_op)]
 #![feature(trait_alias)]