Rollup merge of #68399 - Centril:check-match-unify, r=oli-obk

check_match: misc unifications and ICE fixes

These are some unifications made as a by-product of working on `hir::ExprKind::Let`.

Fixes https://github.com/rust-lang/rust/issues/68396.
Fixes https://github.com/rust-lang/rust/issues/68394.
Fixes https://github.com/rust-lang/rust/issues/68393.

r? @oli-obk @matthewjasper

9 files changed, 127 insertions, 2 deletions

diff --git a/src/test/ui/lint/lint-uppercase-variables.rs b/src/test/ui/lint/lint-uppercase-variables.rs
index 86a39502a81..a98b4f2fd44 100644
--- a/src/test/ui/lint/lint-uppercase-variables.rs
+++ b/src/test/ui/lint/lint-uppercase-variables.rs
@@ -25,6 +25,16 @@ fn main() {
 //~^^^ WARN unused variable: `Foo`
     }
 
+    let Foo = foo::Foo::Foo;
+    //~^ ERROR variable `Foo` should have a snake case name
+    //~^^ WARN `Foo` is named the same as one of the variants of the type `foo::Foo`
+    //~^^^ WARN unused variable: `Foo`
+
+    fn in_param(Foo: foo::Foo) {}
+    //~^ ERROR variable `Foo` should have a snake case name
+    //~^^ WARN `Foo` is named the same as one of the variants of the type `foo::Foo`
+    //~^^^ WARN unused variable: `Foo`
+
     test(1);
 
     let _ = Something { X: 0 };
diff --git a/src/test/ui/lint/lint-uppercase-variables.stderr b/src/test/ui/lint/lint-uppercase-variables.stderr
index b937832ac62..a38f3e7626b 100644
--- a/src/test/ui/lint/lint-uppercase-variables.stderr
+++ b/src/test/ui/lint/lint-uppercase-variables.stderr
@@ -6,6 +6,18 @@ LL |         Foo => {}
    |
    = note: `#[warn(bindings_with_variant_name)]` on by default
 
+warning[E0170]: pattern binding `Foo` is named the same as one of the variants of the type `foo::Foo`
+  --> $DIR/lint-uppercase-variables.rs:28:9
+   |
+LL |     let Foo = foo::Foo::Foo;
+   |         ^^^ help: to match on the variant, qualify the path: `foo::Foo::Foo`
+
+warning[E0170]: pattern binding `Foo` is named the same as one of the variants of the type `foo::Foo`
+  --> $DIR/lint-uppercase-variables.rs:33:17
+   |
+LL |     fn in_param(Foo: foo::Foo) {}
+   |                 ^^^ help: to match on the variant, qualify the path: `foo::Foo::Foo`
+
 warning: unused variable: `Foo`
   --> $DIR/lint-uppercase-variables.rs:22:9
    |
@@ -19,6 +31,18 @@ LL | #![warn(unused)]
    |         ^^^^^^
    = note: `#[warn(unused_variables)]` implied by `#[warn(unused)]`
 
+warning: unused variable: `Foo`
+  --> $DIR/lint-uppercase-variables.rs:28:9
+   |
+LL |     let Foo = foo::Foo::Foo;
+   |         ^^^ help: consider prefixing with an underscore: `_Foo`
+
+warning: unused variable: `Foo`
+  --> $DIR/lint-uppercase-variables.rs:33:17
+   |
+LL |     fn in_param(Foo: foo::Foo) {}
+   |                 ^^^ help: consider prefixing with an underscore: `_Foo`
+
 error: structure field `X` should have a snake case name
   --> $DIR/lint-uppercase-variables.rs:10:5
    |
@@ -49,6 +73,18 @@ error: variable `Foo` should have a snake case name
 LL |         Foo => {}
    |         ^^^ help: convert the identifier to snake case (notice the capitalization): `foo`
 
-error: aborting due to 4 previous errors
+error: variable `Foo` should have a snake case name
+  --> $DIR/lint-uppercase-variables.rs:28:9
+   |
+LL |     let Foo = foo::Foo::Foo;
+   |         ^^^ help: convert the identifier to snake case (notice the capitalization): `foo`
+
+error: variable `Foo` should have a snake case name
+  --> $DIR/lint-uppercase-variables.rs:33:17
+   |
+LL |     fn in_param(Foo: foo::Foo) {}
+   |                 ^^^ help: convert the identifier to snake case (notice the capitalization): `foo`
+
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0170`.
diff --git a/src/test/ui/pattern/issue-68393-let-pat-assoc-constant.rs b/src/test/ui/pattern/issue-68393-let-pat-assoc-constant.rs
new file mode 100644
index 00000000000..95ead6b5d4a
--- /dev/null
+++ b/src/test/ui/pattern/issue-68393-let-pat-assoc-constant.rs
@@ -0,0 +1,26 @@
+pub enum EFoo {
+    A,
+}
+
+pub trait Foo {
+    const X: EFoo;
+}
+
+struct Abc;
+
+impl Foo for Abc {
+    const X: EFoo = EFoo::A;
+}
+
+struct Def;
+impl Foo for Def {
+    const X: EFoo = EFoo::A;
+}
+
+pub fn test<A: Foo, B: Foo>(arg: EFoo, A::X: EFoo) {
+    //~^ ERROR associated consts cannot be referenced in patterns
+    let A::X = arg;
+    //~^ ERROR associated consts cannot be referenced in patterns
+}
+
+fn main() {}
diff --git a/src/test/ui/pattern/issue-68393-let-pat-assoc-constant.stderr b/src/test/ui/pattern/issue-68393-let-pat-assoc-constant.stderr
new file mode 100644
index 00000000000..54ecc24981f
--- /dev/null
+++ b/src/test/ui/pattern/issue-68393-let-pat-assoc-constant.stderr
@@ -0,0 +1,15 @@
+error[E0158]: associated consts cannot be referenced in patterns
+  --> $DIR/issue-68393-let-pat-assoc-constant.rs:20:40
+   |
+LL | pub fn test<A: Foo, B: Foo>(arg: EFoo, A::X: EFoo) {
+   |                                        ^^^^
+
+error[E0158]: associated consts cannot be referenced in patterns
+  --> $DIR/issue-68393-let-pat-assoc-constant.rs:22:9
+   |
+LL |     let A::X = arg;
+   |         ^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0158`.
diff --git a/src/test/ui/pattern/issue-68394-let-pat-runtime-value.rs b/src/test/ui/pattern/issue-68394-let-pat-runtime-value.rs
new file mode 100644
index 00000000000..f10a7f2d8a5
--- /dev/null
+++ b/src/test/ui/pattern/issue-68394-let-pat-runtime-value.rs
@@ -0,0 +1,5 @@
+fn main() {
+    let x = 255u8;
+    let 0u8..=x = 0;
+    //~^ ERROR runtime values cannot be referenced in patterns
+}
diff --git a/src/test/ui/pattern/issue-68394-let-pat-runtime-value.stderr b/src/test/ui/pattern/issue-68394-let-pat-runtime-value.stderr
new file mode 100644
index 00000000000..c1508bd71ff
--- /dev/null
+++ b/src/test/ui/pattern/issue-68394-let-pat-runtime-value.stderr
@@ -0,0 +1,9 @@
+error[E0080]: runtime values cannot be referenced in patterns
+  --> $DIR/issue-68394-let-pat-runtime-value.rs:3:15
+   |
+LL |     let 0u8..=x = 0;
+   |               ^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/pattern/issue-68396-let-float-bug.rs b/src/test/ui/pattern/issue-68396-let-float-bug.rs
new file mode 100644
index 00000000000..afc599a4b22
--- /dev/null
+++ b/src/test/ui/pattern/issue-68396-let-float-bug.rs
@@ -0,0 +1,7 @@
+fn main() {
+    let 1234567890123456789012345678901234567890e-340: f64 = 0.0;
+    //~^ ERROR could not evaluate float literal (see issue #31407)
+
+    fn param(1234567890123456789012345678901234567890e-340: f64) {}
+    //~^ ERROR could not evaluate float literal (see issue #31407)
+}
diff --git a/src/test/ui/pattern/issue-68396-let-float-bug.stderr b/src/test/ui/pattern/issue-68396-let-float-bug.stderr
new file mode 100644
index 00000000000..618aa4b5021
--- /dev/null
+++ b/src/test/ui/pattern/issue-68396-let-float-bug.stderr
@@ -0,0 +1,15 @@
+error[E0080]: could not evaluate float literal (see issue #31407)
+  --> $DIR/issue-68396-let-float-bug.rs:2:9
+   |
+LL |     let 1234567890123456789012345678901234567890e-340: f64 = 0.0;
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0080]: could not evaluate float literal (see issue #31407)
+  --> $DIR/issue-68396-let-float-bug.rs:5:14
+   |
+LL |     fn param(1234567890123456789012345678901234567890e-340: f64) {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/src/test/ui/pattern/usefulness/struct-pattern-match-useless.stderr b/src/test/ui/pattern/usefulness/struct-pattern-match-useless.stderr
index 5b0c9305448..0115fc081a9 100644
--- a/src/test/ui/pattern/usefulness/struct-pattern-match-useless.stderr
+++ b/src/test/ui/pattern/usefulness/struct-pattern-match-useless.stderr
@@ -1,8 +1,10 @@
 error: unreachable pattern
   --> $DIR/struct-pattern-match-useless.rs:12:9
    |
+LL |         Foo { x: _x, y: _y } => (),
+   |         -------------------- matches any value
 LL |         Foo { .. } => ()
-   |         ^^^^^^^^^^
+   |         ^^^^^^^^^^ unreachable pattern
    |
 note: lint level defined here
   --> $DIR/struct-pattern-match-useless.rs:1:9