Add reachable_patterns lint to rfc-2008-non_exhaustive

Add linting on non_exhaustive structs and enum variants

Add ui tests for non_exhaustive reachable lint

Rename to non_exhaustive_omitted_patterns and avoid triggering on if let

src/test/ui/rfc-2008-non-exhaustive/auxiliary/enums.rs

@@ -4,8 +4,29 @@
 pub enum NonExhaustiveEnum {
     Unit,
     Tuple(u32),
-    Struct { field: u32 }
+    Struct { field: u32 },
+}
+
+#[non_exhaustive]
+pub enum NestedNonExhaustive {
+    A(NonExhaustiveEnum),
+    B,
+    C,
 }
 
 #[non_exhaustive]
 pub enum EmptyNonExhaustiveEnum {}
+
+pub enum VariantNonExhaustive {
+    #[non_exhaustive]
+    Bar {
+        x: u32,
+        y: u64,
+    },
+    Baz(u32, u16),
+}
+
+#[non_exhaustive]
+pub enum NonExhaustiveSingleVariant {
+    A(bool),
+}

src/test/ui/rfc-2008-non-exhaustive/auxiliary/structs.rs

@@ -1,3 +1,4 @@
+#[derive(Default)]
 #[non_exhaustive]
 pub struct NormalStruct {
     pub first_field: u16,
@@ -15,7 +16,7 @@ pub struct TupleStruct(pub u16, pub u16);
 pub struct FunctionalRecord {
     pub first_field: u16,
     pub second_field: u16,
-    pub third_field: bool
+    pub third_field: bool,
 }
 
 impl Default for FunctionalRecord {
@@ -23,3 +24,10 @@ impl Default for FunctionalRecord {
         FunctionalRecord { first_field: 640, second_field: 480, third_field: false }
     }
 }
+
+#[derive(Default)]
+#[non_exhaustive]
+pub struct NestedStruct {
+    pub foo: u16,
+    pub bar: NormalStruct,
+}

src/test/ui/rfc-2008-non-exhaustive/reachable-patterns.rs

@@ -0,0 +1,160 @@
+// Test that the `non_exhaustive_omitted_patterns` lint is triggered correctly.
+
+// aux-build:enums.rs
+extern crate enums;
+
+// aux-build:structs.rs
+extern crate structs;
+
+use enums::{
+    EmptyNonExhaustiveEnum, NestedNonExhaustive, NonExhaustiveEnum, NonExhaustiveSingleVariant,
+    VariantNonExhaustive,
+};
+use structs::{FunctionalRecord, NestedStruct, NormalStruct};
+
+#[non_exhaustive]
+#[derive(Default)]
+pub struct Foo {
+    a: u8,
+    b: usize,
+    c: String,
+}
+
+#[non_exhaustive]
+pub enum Bar {
+    A,
+    B,
+    C,
+}
+
+fn main() {
+    let enumeration = Bar::A;
+
+    // Ok: this is a crate local non_exhaustive enum
+    match enumeration {
+        Bar::A => {}
+        Bar::B => {}
+        #[deny(non_exhaustive_omitted_patterns)]
+        _ => {}
+    }
+
+    let non_enum = NonExhaustiveEnum::Unit;
+
+    // Ok: without the attribute
+    match non_enum {
+        NonExhaustiveEnum::Unit => {}
+        NonExhaustiveEnum::Tuple(_) => {}
+        _ => {}
+    }
+
+    match non_enum {
+        NonExhaustiveEnum::Unit => {}
+        NonExhaustiveEnum::Tuple(_) => {}
+        #[deny(non_exhaustive_omitted_patterns)]
+        _ => {}
+    }
+    //~^^ some variants are not matched explicitly
+
+    match non_enum {
+        NonExhaustiveEnum::Unit | NonExhaustiveEnum::Struct { .. } => {}
+        #[deny(non_exhaustive_omitted_patterns)]
+        _ => {}
+    }
+    //~^^ some variants are not matched explicitly
+
+    let x = 5;
+    match non_enum {
+        NonExhaustiveEnum::Unit if x > 10 => {}
+        NonExhaustiveEnum::Tuple(_) => {}
+        NonExhaustiveEnum::Struct { .. } => {}
+        #[deny(non_exhaustive_omitted_patterns)]
+        _ => {}
+    }
+    //~^^ some variants are not matched explicitly
+
+    // Ok: all covered and not `unreachable-patterns`
+    #[deny(unreachable_patterns)]
+    match non_enum {
+        NonExhaustiveEnum::Unit => {}
+        NonExhaustiveEnum::Tuple(_) => {}
+        NonExhaustiveEnum::Struct { .. } => {}
+        #[deny(non_exhaustive_omitted_patterns)]
+        _ => {}
+    }
+
+    #[deny(non_exhaustive_omitted_patterns)]
+    match NestedNonExhaustive::B {
+        NestedNonExhaustive::A(NonExhaustiveEnum::Unit) => {}
+        NestedNonExhaustive::A(_) => {}
+        NestedNonExhaustive::B => {}
+        _ => {}
+    }
+    //~^^ some variants are not matched explicitly
+    //~^^^^^ some variants are not matched explicitly
+
+    // The io::ErrorKind has many `unstable` fields how do they interact with this
+    // lint
+    #[deny(non_exhaustive_omitted_patterns)]
+    match std::io::ErrorKind::Other {
+        std::io::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 => {}
+        std::io::ErrorKind::Unsupported => {}
+        std::io::ErrorKind::OutOfMemory => {}
+        // All stable variants are above and unstable in `_`
+        _ => {}
+    }
+    //~^^ some variants are not matched explicitly
+
+    #[warn(non_exhaustive_omitted_patterns)]
+    match VariantNonExhaustive::Baz(1, 2) {
+        VariantNonExhaustive::Baz(_, _) => {}
+        VariantNonExhaustive::Bar { x, .. } => {}
+    }
+    //~^^ some fields are not explicitly listed
+
+    #[warn(non_exhaustive_omitted_patterns)]
+    let FunctionalRecord { first_field, second_field, .. } = FunctionalRecord::default();
+    //~^ some fields are not explicitly listed
+
+    // Ok: this is local
+    #[warn(non_exhaustive_omitted_patterns)]
+    let Foo { a, b, .. } = Foo::default();
+
+    #[warn(non_exhaustive_omitted_patterns)]
+    let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = NestedStruct::default();
+    //~^ some fields are not explicitly listed
+    //~^^ some fields are not explicitly listed
+
+    // Ok: because this only has 1 variant
+    #[deny(non_exhaustive_omitted_patterns)]
+    match NonExhaustiveSingleVariant::A(true) {
+        NonExhaustiveSingleVariant::A(true) => {}
+        _ => {}
+    }
+
+    #[deny(non_exhaustive_omitted_patterns)]
+    match NonExhaustiveSingleVariant::A(true) {
+        _ => {}
+    }
+    //~^^ some variants are not matched explicitly
+
+    // Ok: we don't lint on `if let` expressions
+    #[deny(non_exhaustive_omitted_patterns)]
+    if let NonExhaustiveEnum::Tuple(_) = non_enum {}
+}

src/test/ui/rfc-2008-non-exhaustive/reachable-patterns.stderr

@@ -0,0 +1,146 @@
+warning: some fields are not explicitly listed
+  --> $DIR/reachable-patterns.rs:127:9
+   |
+LL |         VariantNonExhaustive::Bar { x, .. } => {}
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `y` not listed
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:124:12
+   |
+LL |     #[warn(non_exhaustive_omitted_patterns)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all fields are mentioned explicitly by adding the suggested fields
+   = note: the pattern is of type `VariantNonExhaustive` and the `non_exhaustive_omitted_patterns` attribute was found
+
+warning: some fields are not explicitly listed
+  --> $DIR/reachable-patterns.rs:132:9
+   |
+LL |     let FunctionalRecord { first_field, second_field, .. } = FunctionalRecord::default();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `third_field` not listed
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:131:12
+   |
+LL |     #[warn(non_exhaustive_omitted_patterns)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all fields are mentioned explicitly by adding the suggested fields
+   = note: the pattern is of type `FunctionalRecord` and the `non_exhaustive_omitted_patterns` attribute was found
+
+warning: some fields are not explicitly listed
+  --> $DIR/reachable-patterns.rs:140:29
+   |
+LL |     let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = NestedStruct::default();
+   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `second_field` not listed
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:139:12
+   |
+LL |     #[warn(non_exhaustive_omitted_patterns)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all fields are mentioned explicitly by adding the suggested fields
+   = note: the pattern is of type `NormalStruct` and the `non_exhaustive_omitted_patterns` attribute was found
+
+warning: some fields are not explicitly listed
+  --> $DIR/reachable-patterns.rs:140:9
+   |
+LL |     let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = NestedStruct::default();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `foo` not listed
+   |
+   = help: ensure that all fields are mentioned explicitly by adding the suggested fields
+   = note: the pattern is of type `NestedStruct` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:54:9
+   |
+LL |         _ => {}
+   |         ^ pattern `Struct { .. }` not covered
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:53:16
+   |
+LL |         #[deny(non_exhaustive_omitted_patterns)]
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:61:9
+   |
+LL |         _ => {}
+   |         ^ pattern `Tuple(_)` not covered
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:60:16
+   |
+LL |         #[deny(non_exhaustive_omitted_patterns)]
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:71:9
+   |
+LL |         _ => {}
+   |         ^ pattern `Unit` not covered
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:70:16
+   |
+LL |         #[deny(non_exhaustive_omitted_patterns)]
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:88:32
+   |
+LL |         NestedNonExhaustive::A(_) => {}
+   |                                ^ patterns `Tuple(_)` and `Struct { .. }` not covered
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:85:12
+   |
+LL |     #[deny(non_exhaustive_omitted_patterns)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:90:9
+   |
+LL |         _ => {}
+   |         ^ pattern `C` not covered
+   |
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `NestedNonExhaustive` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:120:9
+   |
+LL |         _ => {}
+   |         ^ patterns `HostUnreachable`, `NetworkUnreachable`, `NetworkDown` and 18 more not covered
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:97:12
+   |
+LL |     #[deny(non_exhaustive_omitted_patterns)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `ErrorKind` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: some variants are not matched explicitly
+  --> $DIR/reachable-patterns.rs:153:9
+   |
+LL |         _ => {}
+   |         ^ pattern `A(_)` not covered
+   |
+note: the lint level is defined here
+  --> $DIR/reachable-patterns.rs:151:12
+   |
+LL |     #[deny(non_exhaustive_omitted_patterns)]
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = help: ensure that all variants are matched explicitly by adding the suggested match arms
+   = note: the matched value is of type `NonExhaustiveSingleVariant` and the `non_exhaustive_omitted_patterns` attribute was found
+
+error: aborting due to 7 previous errors; 4 warnings emitted
+

src/test/ui/rfc-2008-non-exhaustive/struct.stderr

@@ -16,13 +16,13 @@ error[E0603]: tuple struct constructor `TupleStruct` is private
 LL |     let ts_explicit = structs::TupleStruct(640, 480);
    |                                ^^^^^^^^^^^ private tuple struct constructor
    |
-  ::: $DIR/auxiliary/structs.rs:11:24
+  ::: $DIR/auxiliary/structs.rs:12:24
    |
 LL | pub struct TupleStruct(pub u16, pub u16);
    |                        ---------------- a constructor is private if any of the fields is private
    |
 note: the tuple struct constructor `TupleStruct` is defined here
-  --> $DIR/auxiliary/structs.rs:11:1
+  --> $DIR/auxiliary/structs.rs:12:1
    |
 LL | pub struct TupleStruct(pub u16, pub u16);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -34,7 +34,7 @@ LL |     let us_explicit = structs::UnitStruct;
    |                                ^^^^^^^^^^ private unit struct
    |
 note: the unit struct `UnitStruct` is defined here
-  --> $DIR/auxiliary/structs.rs:8:1
+  --> $DIR/auxiliary/structs.rs:9:1
    |
 LL | pub struct UnitStruct;
    | ^^^^^^^^^^^^^^^^^^^^^^