Make OR_PATTERNS_BACK_COMPAT be a 2021 future-incompatible lint

compiler/rustc_lint_defs/src/builtin.rs

@@ -3239,4 +3239,8 @@ declare_lint! {
     pub OR_PATTERNS_BACK_COMPAT,
     Allow,
     "detects usage of old versions of or-patterns",
+    @future_incompatible = FutureIncompatibleInfo {
+        reference: "issue #84869 <https://github.com/rust-lang/rust/issues/84869>",
+        edition: Some(Edition::Edition2021),
+    };
 }

src/test/ui/macros/macro-or-patterns-back-compat.fixed

@@ -2,13 +2,22 @@
 
 #![deny(or_patterns_back_compat)]
 #![allow(unused_macros)]
-macro_rules! foo { ($x:pat_param | $y:pat) => {} } //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
-macro_rules! bar { ($($x:pat_param)+ | $($y:pat)+) => {} } //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+
+macro_rules! foo { ($x:pat_param | $y:pat) => {} }
+//~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+//~| WARN this was previously accepted
+macro_rules! bar { ($($x:pat_param)+ | $($y:pat)+) => {} }
+//~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+//~| WARN this was previously accepted
 macro_rules! baz { ($x:pat_param | $y:pat_param) => {} } // should be ok
 macro_rules! qux { ($x:pat_param | $y:pat) => {} } // should be ok
-macro_rules! ogg { ($x:pat_param | $y:pat_param) => {} } //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+macro_rules! ogg { ($x:pat_param | $y:pat_param) => {} }
+//~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+//~| WARN this was previously accepted
 macro_rules! match_any {
-    ( $expr:expr , $( $( $pat:pat_param )|+ => $expr_arm:expr ),+ ) => { //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+    ( $expr:expr , $( $( $pat:pat_param )|+ => $expr_arm:expr ),+ ) => {
+        //~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+        //~| WARN this was previously accepted
         match $expr {
             $(
                 $( $pat => $expr_arm, )+

src/test/ui/macros/macro-or-patterns-back-compat.rs

@@ -2,13 +2,22 @@
 
 #![deny(or_patterns_back_compat)]
 #![allow(unused_macros)]
-macro_rules! foo { ($x:pat | $y:pat) => {} } //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
-macro_rules! bar { ($($x:pat)+ | $($y:pat)+) => {} } //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+
+macro_rules! foo { ($x:pat | $y:pat) => {} }
+//~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+//~| WARN this was previously accepted
+macro_rules! bar { ($($x:pat)+ | $($y:pat)+) => {} }
+//~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+//~| WARN this was previously accepted
 macro_rules! baz { ($x:pat_param | $y:pat_param) => {} } // should be ok
 macro_rules! qux { ($x:pat_param | $y:pat) => {} } // should be ok
-macro_rules! ogg { ($x:pat | $y:pat_param) => {} } //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+macro_rules! ogg { ($x:pat | $y:pat_param) => {} }
+//~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+//~| WARN this was previously accepted
 macro_rules! match_any {
-    ( $expr:expr , $( $( $pat:pat )|+ => $expr_arm:expr ),+ ) => { //~ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+    ( $expr:expr , $( $( $pat:pat )|+ => $expr_arm:expr ),+ ) => {
+        //~^ ERROR the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
+        //~| WARN this was previously accepted
         match $expr {
             $(
                 $( $pat => $expr_arm, )+

src/test/ui/macros/macro-or-patterns-back-compat.stderr

@@ -1,5 +1,5 @@
 error: the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
-  --> $DIR/macro-or-patterns-back-compat.rs:5:21
+  --> $DIR/macro-or-patterns-back-compat.rs:6:21
    |
 LL | macro_rules! foo { ($x:pat | $y:pat) => {} }
    |                     ^^^^^^ help: use pat_param to preserve semantics: `$x:pat_param`
@@ -9,24 +9,35 @@ note: the lint level is defined here
    |
 LL | #![deny(or_patterns_back_compat)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
+   = note: for more information, see issue #84869 <https://github.com/rust-lang/rust/issues/84869>
 
 error: the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
-  --> $DIR/macro-or-patterns-back-compat.rs:6:23
+  --> $DIR/macro-or-patterns-back-compat.rs:9:23
    |
 LL | macro_rules! bar { ($($x:pat)+ | $($y:pat)+) => {} }
    |                       ^^^^^^ help: use pat_param to preserve semantics: `$x:pat_param`
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
+   = note: for more information, see issue #84869 <https://github.com/rust-lang/rust/issues/84869>
 
 error: the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
-  --> $DIR/macro-or-patterns-back-compat.rs:9:21
+  --> $DIR/macro-or-patterns-back-compat.rs:14:21
    |
 LL | macro_rules! ogg { ($x:pat | $y:pat_param) => {} }
    |                     ^^^^^^ help: use pat_param to preserve semantics: `$x:pat_param`
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
+   = note: for more information, see issue #84869 <https://github.com/rust-lang/rust/issues/84869>
 
 error: the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro
-  --> $DIR/macro-or-patterns-back-compat.rs:11:26
+  --> $DIR/macro-or-patterns-back-compat.rs:18:26
    |
 LL |     ( $expr:expr , $( $( $pat:pat )|+ => $expr_arm:expr ),+ ) => {
    |                          ^^^^^^^^ help: use pat_param to preserve semantics: `$pat:pat_param`
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
+   = note: for more information, see issue #84869 <https://github.com/rust-lang/rust/issues/84869>
 
 error: aborting due to 4 previous errors