fix(elidable_lifetime_names): avoid overlapping spans in suggestions (#15667)

Fixes https://github.com/rust-lang/rust-clippy/issues/14157
Fixes https://github.com/rust-lang/rust-clippy/issues/15666

changelog: [`elidable_lifetime_names`]: avoid overlapping spans in
suggestions

r? clippy

6 files changed, 337 insertions, 1 deletions

diff --git a/tests/ui/crashes/ice-15666.fixed b/tests/ui/crashes/ice-15666.fixed
new file mode 100644
index 00000000000..53b618765c0
--- /dev/null
+++ b/tests/ui/crashes/ice-15666.fixed
@@ -0,0 +1,6 @@
+#![warn(clippy::elidable_lifetime_names)]
+
+struct UnitVariantAccess<'a, 'b, 's>(&'a &'b &'s ());
+trait Trait<'de> {}
+impl<'de> Trait<'de> for UnitVariantAccess<'_, 'de, '_> {}
+//~^ elidable_lifetime_names
diff --git a/tests/ui/crashes/ice-15666.rs b/tests/ui/crashes/ice-15666.rs
new file mode 100644
index 00000000000..1414b3d2035
--- /dev/null
+++ b/tests/ui/crashes/ice-15666.rs
@@ -0,0 +1,6 @@
+#![warn(clippy::elidable_lifetime_names)]
+
+struct UnitVariantAccess<'a, 'b, 's>(&'a &'b &'s ());
+trait Trait<'de> {}
+impl<'de, 'a, 's> Trait<'de> for UnitVariantAccess<'a, 'de, 's> {}
+//~^ elidable_lifetime_names
diff --git a/tests/ui/crashes/ice-15666.stderr b/tests/ui/crashes/ice-15666.stderr
new file mode 100644
index 00000000000..b417c09b5c6
--- /dev/null
+++ b/tests/ui/crashes/ice-15666.stderr
@@ -0,0 +1,16 @@
+error: the following explicit lifetimes could be elided: 'a, 's
+  --> tests/ui/crashes/ice-15666.rs:5:11
+   |
+LL | impl<'de, 'a, 's> Trait<'de> for UnitVariantAccess<'a, 'de, 's> {}
+   |           ^^  ^^                                   ^^       ^^
+   |
+   = note: `-D clippy::elidable-lifetime-names` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::elidable_lifetime_names)]`
+help: elide the lifetimes
+   |
+LL - impl<'de, 'a, 's> Trait<'de> for UnitVariantAccess<'a, 'de, 's> {}
+LL + impl<'de> Trait<'de> for UnitVariantAccess<'_, 'de, '_> {}
+   |
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/elidable_lifetime_names.fixed b/tests/ui/elidable_lifetime_names.fixed
index abeee5c4cef..a6c4cb7a36a 100644
--- a/tests/ui/elidable_lifetime_names.fixed
+++ b/tests/ui/elidable_lifetime_names.fixed
@@ -192,3 +192,85 @@ mod issue13923 {
         x.b
     }
 }
+
+fn issue15666_original() {
+    struct UnitVariantAccess<'a, 'b, 's>(&'a &'b &'s ());
+
+    trait Trait<'de> {}
+
+    //~v elidable_lifetime_names
+    impl<'de> Trait<'de> for UnitVariantAccess<'_, 'de, '_> {}
+    //        ^^  ^^                                   ^^       ^^
+}
+
+#[allow(clippy::upper_case_acronyms)]
+fn issue15666() {
+    struct S1<'a>(&'a ());
+    struct S2<'a, 'b>(&'a &'b ());
+    struct S3<'a, 'b, 'c>(&'a &'b &'c ());
+
+    trait T {}
+    trait TA<'a> {}
+    trait TB<'b> {}
+    trait TC<'c> {}
+    trait TAB<'a, 'b> {}
+    trait TAC<'a, 'c> {}
+    trait TBC<'b, 'c> {}
+    trait TABC<'a, 'b, 'c> {}
+
+    // 1 lifetime
+
+    impl<'a> TA<'a> for S1<'a> {}
+
+    //~v elidable_lifetime_names
+    impl T for S1<'_> {}
+    //   ^^
+
+    // 2 lifetimes
+
+    impl<'a, 'b> TAB<'a, 'b> for S2<'a, 'b> {}
+
+    //~v elidable_lifetime_names
+    impl<'a> TA<'a> for S2<'a, '_> {}
+    //       ^^
+
+    //~v elidable_lifetime_names
+    impl<'b> TB<'b> for S2<'_, 'b> {}
+    //   ^^
+
+    //~v elidable_lifetime_names
+    impl T for S2<'_, '_> {}
+    //   ^^  ^^
+
+    // 3 lifetimes
+
+    impl<'a, 'b, 'c> TABC<'a, 'b, 'c> for S3<'a, 'b, 'c> {}
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b> TAB<'a, 'b> for S3<'a, 'b, '_> {}
+    //           ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'c> TAC<'a, 'c> for S3<'a, '_, 'c> {}
+    //       ^^
+
+    //~v elidable_lifetime_names
+    impl<'a> TA<'a> for S3<'a, '_, '_> {}
+    //       ^^  ^^
+
+    //~v elidable_lifetime_names
+    impl<'b, 'c> TBC<'b, 'c> for S3<'_, 'b, 'c> {}
+    //   ^^
+
+    //~v elidable_lifetime_names
+    impl<'b> TB<'b> for S3<'_, 'b, '_> {}
+    //   ^^      ^^
+
+    //~v elidable_lifetime_names
+    impl<'c> TC<'c> for S3<'_, '_, 'c> {}
+    //   ^^  ^^
+
+    //~v elidable_lifetime_names
+    impl T for S3<'_, '_, '_> {}
+    //   ^^  ^^  ^^
+}
diff --git a/tests/ui/elidable_lifetime_names.rs b/tests/ui/elidable_lifetime_names.rs
index fae3577a8e9..e08056b2fb5 100644
--- a/tests/ui/elidable_lifetime_names.rs
+++ b/tests/ui/elidable_lifetime_names.rs
@@ -192,3 +192,85 @@ mod issue13923 {
         x.b
     }
 }
+
+fn issue15666_original() {
+    struct UnitVariantAccess<'a, 'b, 's>(&'a &'b &'s ());
+
+    trait Trait<'de> {}
+
+    //~v elidable_lifetime_names
+    impl<'de, 'a, 's> Trait<'de> for UnitVariantAccess<'a, 'de, 's> {}
+    //        ^^  ^^                                   ^^       ^^
+}
+
+#[allow(clippy::upper_case_acronyms)]
+fn issue15666() {
+    struct S1<'a>(&'a ());
+    struct S2<'a, 'b>(&'a &'b ());
+    struct S3<'a, 'b, 'c>(&'a &'b &'c ());
+
+    trait T {}
+    trait TA<'a> {}
+    trait TB<'b> {}
+    trait TC<'c> {}
+    trait TAB<'a, 'b> {}
+    trait TAC<'a, 'c> {}
+    trait TBC<'b, 'c> {}
+    trait TABC<'a, 'b, 'c> {}
+
+    // 1 lifetime
+
+    impl<'a> TA<'a> for S1<'a> {}
+
+    //~v elidable_lifetime_names
+    impl<'a> T for S1<'a> {}
+    //   ^^
+
+    // 2 lifetimes
+
+    impl<'a, 'b> TAB<'a, 'b> for S2<'a, 'b> {}
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b> TA<'a> for S2<'a, 'b> {}
+    //       ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b> TB<'b> for S2<'a, 'b> {}
+    //   ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b> T for S2<'a, 'b> {}
+    //   ^^  ^^
+
+    // 3 lifetimes
+
+    impl<'a, 'b, 'c> TABC<'a, 'b, 'c> for S3<'a, 'b, 'c> {}
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> TAB<'a, 'b> for S3<'a, 'b, 'c> {}
+    //           ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> TAC<'a, 'c> for S3<'a, 'b, 'c> {}
+    //       ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> TA<'a> for S3<'a, 'b, 'c> {}
+    //       ^^  ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> TBC<'b, 'c> for S3<'a, 'b, 'c> {}
+    //   ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> TB<'b> for S3<'a, 'b, 'c> {}
+    //   ^^      ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> TC<'c> for S3<'a, 'b, 'c> {}
+    //   ^^  ^^
+
+    //~v elidable_lifetime_names
+    impl<'a, 'b, 'c> T for S3<'a, 'b, 'c> {}
+    //   ^^  ^^  ^^
+}
diff --git a/tests/ui/elidable_lifetime_names.stderr b/tests/ui/elidable_lifetime_names.stderr
index a60dfc69756..03fe383b8f6 100644
--- a/tests/ui/elidable_lifetime_names.stderr
+++ b/tests/ui/elidable_lifetime_names.stderr
@@ -158,5 +158,149 @@ LL |             o: &'t str,
 LL ~         ) -> Content<'t, '_> {
    |
 
-error: aborting due to 12 previous errors
+error: the following explicit lifetimes could be elided: 'a, 's
+  --> tests/ui/elidable_lifetime_names.rs:202:15
+   |
+LL |     impl<'de, 'a, 's> Trait<'de> for UnitVariantAccess<'a, 'de, 's> {}
+   |               ^^  ^^                                   ^^       ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'de, 'a, 's> Trait<'de> for UnitVariantAccess<'a, 'de, 's> {}
+LL +     impl<'de> Trait<'de> for UnitVariantAccess<'_, 'de, '_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a
+  --> tests/ui/elidable_lifetime_names.rs:226:10
+   |
+LL |     impl<'a> T for S1<'a> {}
+   |          ^^           ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a> T for S1<'a> {}
+LL +     impl T for S1<'_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'b
+  --> tests/ui/elidable_lifetime_names.rs:234:14
+   |
+LL |     impl<'a, 'b> TA<'a> for S2<'a, 'b> {}
+   |              ^^                    ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b> TA<'a> for S2<'a, 'b> {}
+LL +     impl<'a> TA<'a> for S2<'a, '_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a
+  --> tests/ui/elidable_lifetime_names.rs:238:10
+   |
+LL |     impl<'a, 'b> TB<'b> for S2<'a, 'b> {}
+   |          ^^                    ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b> TB<'b> for S2<'a, 'b> {}
+LL +     impl<'b> TB<'b> for S2<'_, 'b> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a, 'b
+  --> tests/ui/elidable_lifetime_names.rs:242:10
+   |
+LL |     impl<'a, 'b> T for S2<'a, 'b> {}
+   |          ^^  ^^           ^^  ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b> T for S2<'a, 'b> {}
+LL +     impl T for S2<'_, '_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'c
+  --> tests/ui/elidable_lifetime_names.rs:250:18
+   |
+LL |     impl<'a, 'b, 'c> TAB<'a, 'b> for S3<'a, 'b, 'c> {}
+   |                  ^^                             ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> TAB<'a, 'b> for S3<'a, 'b, 'c> {}
+LL +     impl<'a, 'b> TAB<'a, 'b> for S3<'a, 'b, '_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'b
+  --> tests/ui/elidable_lifetime_names.rs:254:14
+   |
+LL |     impl<'a, 'b, 'c> TAC<'a, 'c> for S3<'a, 'b, 'c> {}
+   |              ^^                             ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> TAC<'a, 'c> for S3<'a, 'b, 'c> {}
+LL +     impl<'a, 'c> TAC<'a, 'c> for S3<'a, '_, 'c> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'b, 'c
+  --> tests/ui/elidable_lifetime_names.rs:258:14
+   |
+LL |     impl<'a, 'b, 'c> TA<'a> for S3<'a, 'b, 'c> {}
+   |              ^^  ^^                    ^^  ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> TA<'a> for S3<'a, 'b, 'c> {}
+LL +     impl<'a> TA<'a> for S3<'a, '_, '_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a
+  --> tests/ui/elidable_lifetime_names.rs:262:10
+   |
+LL |     impl<'a, 'b, 'c> TBC<'b, 'c> for S3<'a, 'b, 'c> {}
+   |          ^^                             ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> TBC<'b, 'c> for S3<'a, 'b, 'c> {}
+LL +     impl<'b, 'c> TBC<'b, 'c> for S3<'_, 'b, 'c> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a, 'c
+  --> tests/ui/elidable_lifetime_names.rs:266:10
+   |
+LL |     impl<'a, 'b, 'c> TB<'b> for S3<'a, 'b, 'c> {}
+   |          ^^      ^^                ^^      ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> TB<'b> for S3<'a, 'b, 'c> {}
+LL +     impl<'b> TB<'b> for S3<'_, 'b, '_> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a, 'b
+  --> tests/ui/elidable_lifetime_names.rs:270:10
+   |
+LL |     impl<'a, 'b, 'c> TC<'c> for S3<'a, 'b, 'c> {}
+   |          ^^  ^^                    ^^  ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> TC<'c> for S3<'a, 'b, 'c> {}
+LL +     impl<'c> TC<'c> for S3<'_, '_, 'c> {}
+   |
+
+error: the following explicit lifetimes could be elided: 'a, 'b, 'c
+  --> tests/ui/elidable_lifetime_names.rs:274:10
+   |
+LL |     impl<'a, 'b, 'c> T for S3<'a, 'b, 'c> {}
+   |          ^^  ^^  ^^           ^^  ^^  ^^
+   |
+help: elide the lifetimes
+   |
+LL -     impl<'a, 'b, 'c> T for S3<'a, 'b, 'c> {}
+LL +     impl T for S3<'_, '_, '_> {}
+   |
+
+error: aborting due to 24 previous errors