Rollup merge of #106353 - lukas-code:reduce-red-lines-in-my-ide, r=wesleywiser

Reduce spans for `unsafe impl` errors

Because huge spans aren't great for IDEs.

Prior art: https://github.com/rust-lang/rust/pull/103749

compiler/rustc_hir_analysis/src/coherence/unsafety.rs

@@ -21,7 +21,7 @@ pub(super) fn check_item(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             (Unsafety::Normal, None, Unsafety::Unsafe, hir::ImplPolarity::Positive) => {
                 struct_span_err!(
                     tcx.sess,
-                    item.span,
+                    tcx.def_span(def_id),
                     E0199,
                     "implementing the trait `{}` is not unsafe",
                     trait_ref.print_only_trait_path()
@@ -38,7 +38,7 @@ pub(super) fn check_item(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             (Unsafety::Unsafe, _, Unsafety::Normal, hir::ImplPolarity::Positive) => {
                 struct_span_err!(
                     tcx.sess,
-                    item.span,
+                    tcx.def_span(def_id),
                     E0200,
                     "the trait `{}` requires an `unsafe impl` declaration",
                     trait_ref.print_only_trait_path()
@@ -61,7 +61,7 @@ pub(super) fn check_item(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             (Unsafety::Normal, Some(attr_name), Unsafety::Normal, hir::ImplPolarity::Positive) => {
                 struct_span_err!(
                     tcx.sess,
-                    item.span,
+                    tcx.def_span(def_id),
                     E0569,
                     "requires an `unsafe impl` declaration due to `#[{}]` attribute",
                     attr_name

src/test/ui/coherence/coherence-default-trait-impl.stderr

@@ -2,7 +2,7 @@ error[E0199]: implementing the trait `MySafeTrait` is not unsafe
   --> $DIR/coherence-default-trait-impl.rs:8:1
    |
 LL | unsafe impl MySafeTrait for Foo {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `unsafe` from this trait implementation
    |
@@ -14,7 +14,7 @@ error[E0200]: the trait `MyUnsafeTrait` requires an `unsafe impl` declaration
   --> $DIR/coherence-default-trait-impl.rs:13:1
    |
 LL | impl MyUnsafeTrait for Foo {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the trait `MyUnsafeTrait` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword
 help: add `unsafe` to this trait implementation

src/test/ui/dropck/dropck-eyepatch-implies-unsafe-impl.stderr

@@ -1,13 +1,8 @@
 error[E0569]: requires an `unsafe impl` declaration due to `#[may_dangle]` attribute
   --> $DIR/dropck-eyepatch-implies-unsafe-impl.rs:21:1
    |
-LL | / impl<#[may_dangle] A, B: fmt::Debug> Drop for Pt<A, B> {
-LL | |
-LL | |
-LL | |     // (unsafe to access self.1  due to #[may_dangle] on A)
-LL | |     fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); }
-LL | | }
-   | |_^
+LL | impl<#[may_dangle] A, B: fmt::Debug> Drop for Pt<A, B> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the trait `Drop` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword
 help: add `unsafe` to this trait implementation
@@ -18,13 +13,8 @@ LL | unsafe impl<#[may_dangle] A, B: fmt::Debug> Drop for Pt<A, B> {
 error[E0569]: requires an `unsafe impl` declaration due to `#[may_dangle]` attribute
   --> $DIR/dropck-eyepatch-implies-unsafe-impl.rs:27:1
    |
-LL | / impl<#[may_dangle] 'a, 'b, B: fmt::Debug> Drop for Pr<'a, 'b, B> {
-LL | |
-LL | |
-LL | |     // (unsafe to access self.1 due to #[may_dangle] on 'a)
-LL | |     fn drop(&mut self) { println!("drop {} {:?}", self.0, self.2); }
-LL | | }
-   | |_^
+LL | impl<#[may_dangle] 'a, 'b, B: fmt::Debug> Drop for Pr<'a, 'b, B> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the trait `Drop` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword
 help: add `unsafe` to this trait implementation

src/test/ui/error-codes/E0199.stderr

@@ -2,7 +2,7 @@ error[E0199]: implementing the trait `Bar` is not unsafe
   --> $DIR/E0199.rs:6:1
    |
 LL | unsafe impl Bar for Foo { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `unsafe` from this trait implementation
    |

src/test/ui/error-codes/E0200.stderr

@@ -2,7 +2,7 @@ error[E0200]: the trait `Bar` requires an `unsafe impl` declaration
   --> $DIR/E0200.rs:5:1
    |
 LL | impl Bar for Foo { }
-   | ^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^
    |
    = note: the trait `Bar` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword
 help: add `unsafe` to this trait implementation

src/test/ui/traits/safety-trait-impl-cc.stderr

@@ -1,12 +1,8 @@
 error[E0200]: the trait `Foo` requires an `unsafe impl` declaration
   --> $DIR/safety-trait-impl-cc.rs:9:1
    |
-LL | / impl lib::Foo for Bar {
-LL | |     fn foo(&self) -> isize {
-LL | |         panic!();
-LL | |     }
-LL | | }
-   | |_^
+LL | impl lib::Foo for Bar {
+   | ^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the trait `Foo` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword
 help: add `unsafe` to this trait implementation

src/test/ui/traits/safety-trait-impl.stderr

@@ -2,7 +2,7 @@ error[E0200]: the trait `UnsafeTrait` requires an `unsafe impl` declaration
   --> $DIR/safety-trait-impl.rs:14:1
    |
 LL | impl UnsafeTrait for u16 { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the trait `UnsafeTrait` enforces invariants that the compiler can't check. Review the trait documentation and make sure this implementation upholds those invariants before adding the `unsafe` keyword
 help: add `unsafe` to this trait implementation
@@ -14,7 +14,7 @@ error[E0199]: implementing the trait `SafeTrait` is not unsafe
   --> $DIR/safety-trait-impl.rs:16:1
    |
 LL | unsafe impl SafeTrait for u32 { }
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `unsafe` from this trait implementation
    |