Auto merge of #6863 - Jarcho:wild_enum_match, r=llogiq

`match_wildcard` improvements

fixes: #6604
fixes: #5733
fixes: #6862

#5733 is only fixed in the normal case, if different paths are used for the variants then the same problem will occur. It's cause by `def_path_str` returning an utterly useless result. I haven't dug into why yet.

For #6604 there should be some discussion before accepting this. It's easy enough to change the message rather than disable the lint for `Option` and `Result`.

changelog: Attempt to find a common path prefix for `match_wildcard_for_single_variants` and `wildcard_enum_match_arm`
changelog: Don't lint op `Option` and `Result` for `match_wildcard_for_single_variants` and `wildcard_enum_match_arm`
changelog: Consider `or` patterns and `Self` prefix for `match_wildcard_for_single_variants` and `wildcard_enum_match_arm`

tests/ui/match_wildcard_for_single_variants.fixed

@@ -15,6 +15,16 @@ enum Color {
     Blue,
     Rgb(u8, u8, u8),
 }
+impl Color {
+    fn f(self) {
+        match self {
+            Self::Red => (),
+            Self::Green => (),
+            Self::Blue => (),
+            Self::Rgb(..) => (),
+        };
+    }
+}
 
 fn main() {
     let f = Foo::A;
@@ -56,4 +66,46 @@ fn main() {
         Color::Rgb(255, _, _) => {},
         _ => {},
     }
+
+    // References shouldn't change anything
+    match &color {
+        &Color::Red => (),
+        Color::Green => (),
+        &Color::Rgb(..) => (),
+        Color::Blue => (),
+    }
+
+    use self::Color as C;
+
+    match color {
+        C::Red => (),
+        C::Green => (),
+        C::Rgb(..) => (),
+        C::Blue => (),
+    }
+
+    match color {
+        C::Red => (),
+        Color::Green => (),
+        Color::Rgb(..) => (),
+        Color::Blue => (),
+    }
+
+    match Some(0) {
+        Some(0) => 0,
+        Some(_) => 1,
+        _ => 2,
+    };
+
+    #[non_exhaustive]
+    enum Bar {
+        A,
+        B,
+        C,
+    }
+    match Bar::A {
+        Bar::A => (),
+        Bar::B => (),
+        _ => (),
+    };
 }

tests/ui/match_wildcard_for_single_variants.rs

@@ -15,6 +15,16 @@ enum Color {
     Blue,
     Rgb(u8, u8, u8),
 }
+impl Color {
+    fn f(self) {
+        match self {
+            Self::Red => (),
+            Self::Green => (),
+            Self::Blue => (),
+            _ => (),
+        };
+    }
+}
 
 fn main() {
     let f = Foo::A;
@@ -56,4 +66,46 @@ fn main() {
         Color::Rgb(255, _, _) => {},
         _ => {},
     }
+
+    // References shouldn't change anything
+    match &color {
+        &Color::Red => (),
+        Color::Green => (),
+        &Color::Rgb(..) => (),
+        &_ => (),
+    }
+
+    use self::Color as C;
+
+    match color {
+        C::Red => (),
+        C::Green => (),
+        C::Rgb(..) => (),
+        _ => (),
+    }
+
+    match color {
+        C::Red => (),
+        Color::Green => (),
+        Color::Rgb(..) => (),
+        _ => (),
+    }
+
+    match Some(0) {
+        Some(0) => 0,
+        Some(_) => 1,
+        _ => 2,
+    };
+
+    #[non_exhaustive]
+    enum Bar {
+        A,
+        B,
+        C,
+    }
+    match Bar::A {
+        Bar::A => (),
+        Bar::B => (),
+        _ => (),
+    };
 }

tests/ui/match_wildcard_for_single_variants.stderr

@@ -1,28 +1,52 @@
-error: wildcard match will miss any future added variants
-  --> $DIR/match_wildcard_for_single_variants.rs:24:9
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:24:13
    |
-LL |         _ => {},
-   |         ^ help: try this: `Foo::C`
+LL |             _ => (),
+   |             ^ help: try this: `Self::Rgb(..)`
    |
    = note: `-D clippy::match-wildcard-for-single-variants` implied by `-D warnings`
 
-error: wildcard match will miss any future added variants
+error: wildcard matches only a single variant and will also match any future added variants
   --> $DIR/match_wildcard_for_single_variants.rs:34:9
    |
 LL |         _ => {},
-   |         ^ help: try this: `Color::Blue`
+   |         ^ help: try this: `Foo::C`
 
-error: wildcard match will miss any future added variants
-  --> $DIR/match_wildcard_for_single_variants.rs:42:9
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:44:9
    |
 LL |         _ => {},
    |         ^ help: try this: `Color::Blue`
 
-error: wildcard match will miss any future added variants
-  --> $DIR/match_wildcard_for_single_variants.rs:48:9
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:52:9
    |
 LL |         _ => {},
    |         ^ help: try this: `Color::Blue`
 
-error: aborting due to 4 previous errors
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:58:9
+   |
+LL |         _ => {},
+   |         ^ help: try this: `Color::Blue`
+
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:75:9
+   |
+LL |         &_ => (),
+   |         ^^ help: try this: `Color::Blue`
+
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:84:9
+   |
+LL |         _ => (),
+   |         ^ help: try this: `C::Blue`
+
+error: wildcard matches only a single variant and will also match any future added variants
+  --> $DIR/match_wildcard_for_single_variants.rs:91:9
+   |
+LL |         _ => (),
+   |         ^ help: try this: `Color::Blue`
+
+error: aborting due to 8 previous errors
 

tests/ui/wildcard_enum_match_arm.fixed

@@ -77,7 +77,7 @@ fn main() {
     let error_kind = ErrorKind::NotFound;
     match error_kind {
         ErrorKind::NotFound => {},
-        std::io::ErrorKind::PermissionDenied | std::io::ErrorKind::ConnectionRefused | std::io::ErrorKind::ConnectionReset | std::io::ErrorKind::ConnectionAborted | std::io::ErrorKind::NotConnected | std::io::ErrorKind::AddrInUse | std::io::ErrorKind::AddrNotAvailable | std::io::ErrorKind::BrokenPipe | std::io::ErrorKind::AlreadyExists | std::io::ErrorKind::WouldBlock | std::io::ErrorKind::InvalidInput | std::io::ErrorKind::InvalidData | std::io::ErrorKind::TimedOut | std::io::ErrorKind::WriteZero | std::io::ErrorKind::Interrupted | std::io::ErrorKind::Other | std::io::ErrorKind::UnexpectedEof | _ => {},
+        ErrorKind::PermissionDenied | ErrorKind::ConnectionRefused | ErrorKind::ConnectionReset | ErrorKind::ConnectionAborted | ErrorKind::NotConnected | ErrorKind::AddrInUse | ErrorKind::AddrNotAvailable | ErrorKind::BrokenPipe | ErrorKind::AlreadyExists | ErrorKind::WouldBlock | ErrorKind::InvalidInput | ErrorKind::InvalidData | ErrorKind::TimedOut | ErrorKind::WriteZero | ErrorKind::Interrupted | ErrorKind::Other | ErrorKind::UnexpectedEof | _ => {},
     }
     match error_kind {
         ErrorKind::NotFound => {},

tests/ui/wildcard_enum_match_arm.stderr

@@ -1,4 +1,4 @@
-error: wildcard match will miss any future added variants
+error: wildcard match will also match any future added variants
   --> $DIR/wildcard_enum_match_arm.rs:39:9
    |
 LL |         _ => eprintln!("Not red"),
@@ -10,29 +10,29 @@ note: the lint level is defined here
 LL | #![deny(clippy::wildcard_enum_match_arm)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: wildcard match will miss any future added variants
+error: wildcard match will also match any future added variants
   --> $DIR/wildcard_enum_match_arm.rs:43:9
    |
 LL |         _not_red => eprintln!("Not red"),
    |         ^^^^^^^^ help: try this: `_not_red @ Color::Green | _not_red @ Color::Blue | _not_red @ Color::Rgb(..) | _not_red @ Color::Cyan`
 
-error: wildcard match will miss any future added variants
+error: wildcard match will also match any future added variants
   --> $DIR/wildcard_enum_match_arm.rs:47:9
    |
 LL |         not_red => format!("{:?}", not_red),
    |         ^^^^^^^ help: try this: `not_red @ Color::Green | not_red @ Color::Blue | not_red @ Color::Rgb(..) | not_red @ Color::Cyan`
 
-error: wildcard match will miss any future added variants
+error: wildcard match will also match any future added variants
   --> $DIR/wildcard_enum_match_arm.rs:63:9
    |
 LL |         _ => "No red",
    |         ^ help: try this: `Color::Red | Color::Green | Color::Blue | Color::Rgb(..) | Color::Cyan`
 
-error: match on non-exhaustive enum doesn't explicitly match all known variants
+error: wildcard matches known variants and will also match future added variants
   --> $DIR/wildcard_enum_match_arm.rs:80:9
    |
 LL |         _ => {},
-   |         ^ help: try this: `std::io::ErrorKind::PermissionDenied | std::io::ErrorKind::ConnectionRefused | std::io::ErrorKind::ConnectionReset | std::io::ErrorKind::ConnectionAborted | std::io::ErrorKind::NotConnected | std::io::ErrorKind::AddrInUse | std::io::ErrorKind::AddrNotAvailable | std::io::ErrorKind::BrokenPipe | std::io::ErrorKind::AlreadyExists | std::io::ErrorKind::WouldBlock | std::io::ErrorKind::InvalidInput | std::io::ErrorKind::InvalidData | std::io::ErrorKind::TimedOut | std::io::ErrorKind::WriteZero | std::io::ErrorKind::Interrupted | std::io::ErrorKind::Other | std::io::ErrorKind::UnexpectedEof | _`
+   |         ^ help: try this: `ErrorKind::PermissionDenied | ErrorKind::ConnectionRefused | ErrorKind::ConnectionReset | ErrorKind::ConnectionAborted | ErrorKind::NotConnected | ErrorKind::AddrInUse | ErrorKind::AddrNotAvailable | ErrorKind::BrokenPipe | ErrorKind::AlreadyExists | ErrorKind::WouldBlock | ErrorKind::InvalidInput | ErrorKind::InvalidData | ErrorKind::TimedOut | ErrorKind::WriteZero | ErrorKind::Interrupted | ErrorKind::Other | ErrorKind::UnexpectedEof | _`
 
 error: aborting due to 5 previous errors