Detect pub structs never constructed and unused associated constants in traits

6 files changed, 119 insertions, 10 deletions

diff --git a/tests/ui/lint/dead-code/lint-dead-code-1.rs b/tests/ui/lint/dead-code/lint-dead-code-1.rs
index ddcafedf7bc..3386dfa4747 100644
--- a/tests/ui/lint/dead-code/lint-dead-code-1.rs
+++ b/tests/ui/lint/dead-code/lint-dead-code-1.rs
@@ -46,11 +46,10 @@ struct SemiUsedStruct;
 impl SemiUsedStruct {
     fn la_la_la() {}
 }
-struct StructUsedAsField;
+struct StructUsedAsField; //~ ERROR struct `StructUsedAsField` is never constructed
 pub struct StructUsedInEnum;
 struct StructUsedInGeneric;
-pub struct PubStruct2 {
-    #[allow(dead_code)]
+pub struct PubStruct2 { //~ ERROR struct `PubStruct2` is never constructed
     struct_used_as_field: *const StructUsedAsField
 }
 
diff --git a/tests/ui/lint/dead-code/lint-dead-code-1.stderr b/tests/ui/lint/dead-code/lint-dead-code-1.stderr
index eb728b5b930..b0163df8855 100644
--- a/tests/ui/lint/dead-code/lint-dead-code-1.stderr
+++ b/tests/ui/lint/dead-code/lint-dead-code-1.stderr
@@ -22,14 +22,26 @@ error: struct `PrivStruct` is never constructed
 LL | struct PrivStruct;
    |        ^^^^^^^^^^
 
+error: struct `StructUsedAsField` is never constructed
+  --> $DIR/lint-dead-code-1.rs:49:8
+   |
+LL | struct StructUsedAsField;
+   |        ^^^^^^^^^^^^^^^^^
+
+error: struct `PubStruct2` is never constructed
+  --> $DIR/lint-dead-code-1.rs:52:12
+   |
+LL | pub struct PubStruct2 {
+   |            ^^^^^^^^^^
+
 error: enum `priv_enum` is never used
-  --> $DIR/lint-dead-code-1.rs:64:6
+  --> $DIR/lint-dead-code-1.rs:63:6
    |
 LL | enum priv_enum { foo2, bar2 }
    |      ^^^^^^^^^
 
 error: variant `bar3` is never constructed
-  --> $DIR/lint-dead-code-1.rs:67:5
+  --> $DIR/lint-dead-code-1.rs:66:5
    |
 LL | enum used_enum {
    |      --------- variant in this enum
@@ -38,25 +50,25 @@ LL |     bar3
    |     ^^^^
 
 error: function `priv_fn` is never used
-  --> $DIR/lint-dead-code-1.rs:88:4
+  --> $DIR/lint-dead-code-1.rs:87:4
    |
 LL | fn priv_fn() {
    |    ^^^^^^^
 
 error: function `foo` is never used
-  --> $DIR/lint-dead-code-1.rs:93:4
+  --> $DIR/lint-dead-code-1.rs:92:4
    |
 LL | fn foo() {
    |    ^^^
 
 error: function `bar` is never used
-  --> $DIR/lint-dead-code-1.rs:98:4
+  --> $DIR/lint-dead-code-1.rs:97:4
    |
 LL | fn bar() {
    |    ^^^
 
 error: function `baz` is never used
-  --> $DIR/lint-dead-code-1.rs:102:4
+  --> $DIR/lint-dead-code-1.rs:101:4
    |
 LL | fn baz() -> impl Copy {
    |    ^^^
@@ -67,5 +79,5 @@ error: struct `Bar` is never constructed
 LL |     pub struct Bar;
    |                ^^^
 
-error: aborting due to 10 previous errors
+error: aborting due to 12 previous errors
 
diff --git a/tests/ui/lint/dead-code/unused-assoc-const.rs b/tests/ui/lint/dead-code/unused-assoc-const.rs
new file mode 100644
index 00000000000..36e8315ad36
--- /dev/null
+++ b/tests/ui/lint/dead-code/unused-assoc-const.rs
@@ -0,0 +1,20 @@
+#![deny(dead_code)]
+
+trait Trait {
+    const UNUSED_CONST: i32; //~ ERROR associated constant `UNUSED_CONST` is never used
+    const USED_CONST: i32;
+
+    fn foo(&self) {}
+}
+
+pub struct T(());
+
+impl Trait for T {
+    const UNUSED_CONST: i32 = 0;
+    const USED_CONST: i32 = 1;
+}
+
+fn main() {
+    T(()).foo();
+    T::USED_CONST;
+}
diff --git a/tests/ui/lint/dead-code/unused-assoc-const.stderr b/tests/ui/lint/dead-code/unused-assoc-const.stderr
new file mode 100644
index 00000000000..78296d70663
--- /dev/null
+++ b/tests/ui/lint/dead-code/unused-assoc-const.stderr
@@ -0,0 +1,16 @@
+error: associated constant `UNUSED_CONST` is never used
+  --> $DIR/unused-assoc-const.rs:4:11
+   |
+LL | trait Trait {
+   |       ----- associated constant in this trait
+LL |     const UNUSED_CONST: i32;
+   |           ^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/unused-assoc-const.rs:1:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/lint/dead-code/unused-pub-struct.rs b/tests/ui/lint/dead-code/unused-pub-struct.rs
new file mode 100644
index 00000000000..aaf4dd612de
--- /dev/null
+++ b/tests/ui/lint/dead-code/unused-pub-struct.rs
@@ -0,0 +1,48 @@
+#![deny(dead_code)]
+
+pub struct NotLint1(());
+pub struct NotLint2(std::marker::PhantomData<i32>);
+
+pub struct NeverConstructed(i32); //~ ERROR struct `NeverConstructed` is never constructed
+
+impl NeverConstructed {
+    pub fn not_construct_self(&self) {}
+}
+
+impl Clone for NeverConstructed {
+    fn clone(&self) -> NeverConstructed {
+        NeverConstructed(0)
+    }
+}
+
+pub trait Trait {
+    fn not_construct_self(&self);
+}
+
+impl Trait for NeverConstructed {
+    fn not_construct_self(&self) {
+        self.0;
+    }
+}
+
+pub struct Constructed(i32);
+
+impl Constructed {
+    pub fn construct_self() -> Self {
+        Constructed(0)
+    }
+}
+
+impl Clone for Constructed {
+    fn clone(&self) -> Constructed {
+        Constructed(0)
+    }
+}
+
+impl Trait for Constructed {
+    fn not_construct_self(&self) {
+        self.0;
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/lint/dead-code/unused-pub-struct.stderr b/tests/ui/lint/dead-code/unused-pub-struct.stderr
new file mode 100644
index 00000000000..3667ddb97bd
--- /dev/null
+++ b/tests/ui/lint/dead-code/unused-pub-struct.stderr
@@ -0,0 +1,14 @@
+error: struct `NeverConstructed` is never constructed
+  --> $DIR/unused-pub-struct.rs:6:12
+   |
+LL | pub struct NeverConstructed(i32);
+   |            ^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/unused-pub-struct.rs:1:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: aborting due to 1 previous error
+