Auto merge of #74963 - JohnTitor:ptn-ice, r=petrochenkov

Fix ICEs with `@ ..` binding

This reverts #74557 and introduces an alternative fix while ensuring that #74954 is not broken.
The diagnostics are verbose though, it fixes three related issues.
cc #74954, #74539, and #74702

5 files changed, 95 insertions, 0 deletions

diff --git a/src/test/ui/pattern/issue-74539.rs b/src/test/ui/pattern/issue-74539.rs
new file mode 100644
index 00000000000..0b25f87ec53
--- /dev/null
+++ b/src/test/ui/pattern/issue-74539.rs
@@ -0,0 +1,15 @@
+enum E {
+    A(u8, u8),
+}
+
+fn main() {
+    let e = E::A(2, 3);
+    match e {
+        E::A(x @ ..) => {
+            //~^ ERROR: `x @` is not allowed in a tuple struct
+            //~| ERROR: `..` patterns are not allowed here
+            //~| ERROR: this pattern has 1 field, but the corresponding tuple variant has 2 fields
+            x
+        }
+    };
+}
diff --git a/src/test/ui/pattern/issue-74539.stderr b/src/test/ui/pattern/issue-74539.stderr
new file mode 100644
index 00000000000..cbc90b5397d
--- /dev/null
+++ b/src/test/ui/pattern/issue-74539.stderr
@@ -0,0 +1,32 @@
+error: `x @` is not allowed in a tuple struct
+  --> $DIR/issue-74539.rs:8:14
+   |
+LL |         E::A(x @ ..) => {
+   |              ^^^^^^ this is only allowed in slice patterns
+   |
+   = help: remove this and bind each tuple field independently
+help: if you don't need to use the contents of x, discard the tuple's remaining fields
+   |
+LL |         E::A(..) => {
+   |              ^^
+
+error: `..` patterns are not allowed here
+  --> $DIR/issue-74539.rs:8:18
+   |
+LL |         E::A(x @ ..) => {
+   |                  ^^
+   |
+   = note: only allowed in tuple, tuple struct, and slice patterns
+
+error[E0023]: this pattern has 1 field, but the corresponding tuple variant has 2 fields
+  --> $DIR/issue-74539.rs:8:9
+   |
+LL |     A(u8, u8),
+   |     --------- tuple variant defined here
+...
+LL |         E::A(x @ ..) => {
+   |         ^^^^^^^^^^^^ expected 2 fields, found 1
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0023`.
diff --git a/src/test/ui/pattern/issue-74702.rs b/src/test/ui/pattern/issue-74702.rs
new file mode 100644
index 00000000000..0aeb3b217a2
--- /dev/null
+++ b/src/test/ui/pattern/issue-74702.rs
@@ -0,0 +1,7 @@
+fn main() {
+    let (foo @ ..,) = (0, 0);
+    //~^ ERROR: `foo @` is not allowed in a tuple
+    //~| ERROR: `..` patterns are not allowed here
+    //~| ERROR: mismatched types
+    dbg!(foo);
+}
diff --git a/src/test/ui/pattern/issue-74702.stderr b/src/test/ui/pattern/issue-74702.stderr
new file mode 100644
index 00000000000..aca5c9aed96
--- /dev/null
+++ b/src/test/ui/pattern/issue-74702.stderr
@@ -0,0 +1,34 @@
+error: `foo @` is not allowed in a tuple
+  --> $DIR/issue-74702.rs:2:10
+   |
+LL |     let (foo @ ..,) = (0, 0);
+   |          ^^^^^^^^ this is only allowed in slice patterns
+   |
+   = help: remove this and bind each tuple field independently
+help: if you don't need to use the contents of foo, discard the tuple's remaining fields
+   |
+LL |     let (..,) = (0, 0);
+   |          ^^
+
+error: `..` patterns are not allowed here
+  --> $DIR/issue-74702.rs:2:16
+   |
+LL |     let (foo @ ..,) = (0, 0);
+   |                ^^
+   |
+   = note: only allowed in tuple, tuple struct, and slice patterns
+
+error[E0308]: mismatched types
+  --> $DIR/issue-74702.rs:2:9
+   |
+LL |     let (foo @ ..,) = (0, 0);
+   |         ^^^^^^^^^^^   ------ this expression has type `({integer}, {integer})`
+   |         |
+   |         expected a tuple with 2 elements, found one with 1 element
+   |
+   = note: expected tuple `({integer}, {integer})`
+              found tuple `(_,)`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/pattern/issue-74954.rs b/src/test/ui/pattern/issue-74954.rs
new file mode 100644
index 00000000000..269ec3c7abe
--- /dev/null
+++ b/src/test/ui/pattern/issue-74954.rs
@@ -0,0 +1,7 @@
+// check-pass
+
+fn main() {
+    if let Some([b'@', filename @ ..]) = Some(b"@abc123") {
+        println!("filename {:?}", filename);
+    }
+}