Mark assoc tys live only if the trait is live

8 files changed, 50 insertions, 20 deletions

diff --git a/tests/ui/const-generics/cross_crate_complex.rs b/tests/ui/const-generics/cross_crate_complex.rs
index d13b69aa0cf..b44d889f5e9 100644
--- a/tests/ui/const-generics/cross_crate_complex.rs
+++ b/tests/ui/const-generics/cross_crate_complex.rs
@@ -11,6 +11,7 @@ async fn foo() {
     async_in_foo(async_out_foo::<4>().await).await;
 }
 
+#[allow(dead_code)]
 struct Faz<const N: usize>;
 
 impl<const N: usize> Foo<N> for Faz<N> {}
diff --git a/tests/ui/generic-associated-types/missing-bounds.fixed b/tests/ui/generic-associated-types/missing-bounds.fixed
index 703d3c1e0fb..ff69016d862 100644
--- a/tests/ui/generic-associated-types/missing-bounds.fixed
+++ b/tests/ui/generic-associated-types/missing-bounds.fixed
@@ -2,6 +2,7 @@
 
 use std::ops::Add;
 
+#[allow(dead_code)]
 struct A<B>(B);
 
 impl<B> Add for A<B> where B: Add<Output = B> {
@@ -12,6 +13,7 @@ impl<B> Add for A<B> where B: Add<Output = B> {
     }
 }
 
+#[allow(dead_code)]
 struct C<B>(B);
 
 impl<B: Add<Output = B>> Add for C<B> {
@@ -22,6 +24,7 @@ impl<B: Add<Output = B>> Add for C<B> {
     }
 }
 
+#[allow(dead_code)]
 struct D<B>(B);
 
 impl<B: std::ops::Add<Output = B>> Add for D<B> {
@@ -32,6 +35,7 @@ impl<B: std::ops::Add<Output = B>> Add for D<B> {
     }
 }
 
+#[allow(dead_code)]
 struct E<B>(B);
 
 impl<B: Add<Output = B>> Add for E<B> where B: Add<Output = B> {
diff --git a/tests/ui/generic-associated-types/missing-bounds.rs b/tests/ui/generic-associated-types/missing-bounds.rs
index f40b4228873..1f83356c2fa 100644
--- a/tests/ui/generic-associated-types/missing-bounds.rs
+++ b/tests/ui/generic-associated-types/missing-bounds.rs
@@ -2,6 +2,7 @@
 
 use std::ops::Add;
 
+#[allow(dead_code)]
 struct A<B>(B);
 
 impl<B> Add for A<B> where B: Add {
@@ -12,6 +13,7 @@ impl<B> Add for A<B> where B: Add {
     }
 }
 
+#[allow(dead_code)]
 struct C<B>(B);
 
 impl<B: Add> Add for C<B> {
@@ -22,6 +24,7 @@ impl<B: Add> Add for C<B> {
     }
 }
 
+#[allow(dead_code)]
 struct D<B>(B);
 
 impl<B> Add for D<B> {
@@ -32,6 +35,7 @@ impl<B> Add for D<B> {
     }
 }
 
+#[allow(dead_code)]
 struct E<B>(B);
 
 impl<B: Add> Add for E<B> where <B as Add>::Output = B {
diff --git a/tests/ui/generic-associated-types/missing-bounds.stderr b/tests/ui/generic-associated-types/missing-bounds.stderr
index 1d7d80d1b07..0f0dc24c06c 100644
--- a/tests/ui/generic-associated-types/missing-bounds.stderr
+++ b/tests/ui/generic-associated-types/missing-bounds.stderr
@@ -1,5 +1,5 @@
 error: equality constraints are not yet supported in `where` clauses
-  --> $DIR/missing-bounds.rs:37:33
+  --> $DIR/missing-bounds.rs:41:33
    |
 LL | impl<B: Add> Add for E<B> where <B as Add>::Output = B {
    |                                 ^^^^^^^^^^^^^^^^^^^^^^ not supported
@@ -11,7 +11,7 @@ LL | impl<B: Add> Add for E<B> where B: Add<Output = B> {
    |                                 ~~~~~~~~~~~~~~~~~~
 
 error[E0308]: mismatched types
-  --> $DIR/missing-bounds.rs:11:11
+  --> $DIR/missing-bounds.rs:12:11
    |
 LL | impl<B> Add for A<B> where B: Add {
    |      - expected this type parameter
@@ -24,14 +24,14 @@ LL |         A(self.0 + rhs.0)
    = note: expected type parameter `B`
              found associated type `<B as Add>::Output`
 help: the type constructed contains `<B as Add>::Output` due to the type of the argument passed
-  --> $DIR/missing-bounds.rs:11:9
+  --> $DIR/missing-bounds.rs:12:9
    |
 LL |         A(self.0 + rhs.0)
    |         ^^--------------^
    |           |
    |           this argument influences the type of `A`
 note: tuple struct defined here
-  --> $DIR/missing-bounds.rs:5:8
+  --> $DIR/missing-bounds.rs:6:8
    |
 LL | struct A<B>(B);
    |        ^
@@ -41,7 +41,7 @@ LL | impl<B> Add for A<B> where B: Add<Output = B> {
    |                                  ++++++++++++
 
 error[E0308]: mismatched types
-  --> $DIR/missing-bounds.rs:21:14
+  --> $DIR/missing-bounds.rs:23:14
    |
 LL | impl<B: Add> Add for C<B> {
    |      - expected this type parameter
@@ -54,7 +54,7 @@ LL |         Self(self.0 + rhs.0)
    = note: expected type parameter `B`
              found associated type `<B as Add>::Output`
 note: tuple struct defined here
-  --> $DIR/missing-bounds.rs:15:8
+  --> $DIR/missing-bounds.rs:17:8
    |
 LL | struct C<B>(B);
    |        ^
@@ -64,7 +64,7 @@ LL | impl<B: Add<Output = B>> Add for C<B> {
    |            ++++++++++++
 
 error[E0369]: cannot add `B` to `B`
-  --> $DIR/missing-bounds.rs:31:21
+  --> $DIR/missing-bounds.rs:34:21
    |
 LL |         Self(self.0 + rhs.0)
    |              ------ ^ ----- B
@@ -77,7 +77,7 @@ LL | impl<B: std::ops::Add<Output = B>> Add for D<B> {
    |       +++++++++++++++++++++++++++
 
 error[E0308]: mismatched types
-  --> $DIR/missing-bounds.rs:42:14
+  --> $DIR/missing-bounds.rs:46:14
    |
 LL | impl<B: Add> Add for E<B> where <B as Add>::Output = B {
    |      - expected this type parameter
@@ -90,7 +90,7 @@ LL |         Self(self.0 + rhs.0)
    = note: expected type parameter `B`
              found associated type `<B as Add>::Output`
 note: tuple struct defined here
-  --> $DIR/missing-bounds.rs:35:8
+  --> $DIR/missing-bounds.rs:39:8
    |
 LL | struct E<B>(B);
    |        ^
diff --git a/tests/ui/lint/dead-code/unused-trait-with-assoc-ty.rs b/tests/ui/lint/dead-code/unused-trait-with-assoc-ty.rs
new file mode 100644
index 00000000000..e8116d83ebf
--- /dev/null
+++ b/tests/ui/lint/dead-code/unused-trait-with-assoc-ty.rs
@@ -0,0 +1,11 @@
+#![deny(dead_code)]
+
+struct T1; //~ ERROR struct `T1` is never constructed
+
+trait Foo { type Unused; } //~ ERROR trait `Foo` is never used
+impl Foo for T1 { type Unused = Self; }
+
+pub trait Bar { type Used; }
+impl Bar for T1 { type Used = Self; }
+
+fn main() {}
diff --git a/tests/ui/lint/dead-code/unused-trait-with-assoc-ty.stderr b/tests/ui/lint/dead-code/unused-trait-with-assoc-ty.stderr
new file mode 100644
index 00000000000..ab73c640634
--- /dev/null
+++ b/tests/ui/lint/dead-code/unused-trait-with-assoc-ty.stderr
@@ -0,0 +1,20 @@
+error: struct `T1` is never constructed
+  --> $DIR/unused-trait-with-assoc-ty.rs:3:8
+   |
+LL | struct T1;
+   |        ^^
+   |
+note: the lint level is defined here
+  --> $DIR/unused-trait-with-assoc-ty.rs:1:9
+   |
+LL | #![deny(dead_code)]
+   |         ^^^^^^^^^
+
+error: trait `Foo` is never used
+  --> $DIR/unused-trait-with-assoc-ty.rs:5:7
+   |
+LL | trait Foo { type Unused; }
+   |       ^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/pattern/issue-22546.rs b/tests/ui/pattern/issue-22546.rs
index fd1d5fb6c47..d5c5b68be78 100644
--- a/tests/ui/pattern/issue-22546.rs
+++ b/tests/ui/pattern/issue-22546.rs
@@ -15,7 +15,7 @@ impl<T: ::std::fmt::Display> Foo<T> {
     }
 }
 
-trait Tr { //~ WARN trait `Tr` is never used
+trait Tr {
     type U;
 }
 
diff --git a/tests/ui/pattern/issue-22546.stderr b/tests/ui/pattern/issue-22546.stderr
deleted file mode 100644
index e067a95e422..00000000000
--- a/tests/ui/pattern/issue-22546.stderr
+++ /dev/null
@@ -1,10 +0,0 @@
-warning: trait `Tr` is never used
-  --> $DIR/issue-22546.rs:18:7
-   |
-LL | trait Tr {
-   |       ^^
-   |
-   = note: `#[warn(dead_code)]` on by default
-
-warning: 1 warning emitted
-