Always print '_, even for erased lifetimes.

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1088,17 +1088,9 @@ pub trait PrettyPrinter<'tcx>:
                         .generics_of(principal.def_id)
                         .own_substs_no_defaults(cx.tcx(), principal.substs);
 
-                    // Don't print `'_` if there's no unerased regions.
-                    let print_regions = args.iter().any(|arg| match arg.unpack() {
-                        GenericArgKind::Lifetime(r) => !r.is_erased(),
-                        _ => false,
-                    });
-                    let mut args = args.iter().cloned().filter(|arg| match arg.unpack() {
-                        GenericArgKind::Lifetime(_) => print_regions,
-                        _ => true,
-                    });
                     let mut projections = predicates.projection_bounds();
 
+                    let mut args = args.iter().cloned();
                     let arg0 = args.next();
                     let projection0 = projections.next();
                     if arg0.is_some() || projection0.is_some() {
@@ -1847,22 +1839,11 @@ impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
     ) -> Result<Self::Path, Self::Error> {
         self = print_prefix(self)?;
 
-        // Don't print `'_` if there's no unerased regions.
+        if args.first().is_some() {
-        let print_regions = self.tcx.sess.verbose()
-            || args.iter().any(|arg| match arg.unpack() {
-                GenericArgKind::Lifetime(r) => !r.is_erased(),
-                _ => false,
-            });
-        let args = args.iter().cloned().filter(|arg| match arg.unpack() {
-            GenericArgKind::Lifetime(_) => print_regions,
-            _ => true,
-        });
-
-        if args.clone().next().is_some() {
             if self.in_value {
                 write!(self, "::")?;
             }
-            self.generic_delimiters(|cx| cx.comma_sep(args))
+            self.generic_delimiters(|cx| cx.comma_sep(args.iter().cloned()))
         } else {
             Ok(self)
         }

src/test/mir-opt/derefer_complex_case.main.Derefer.diff

@@ -3,15 +3,15 @@
   
   fn main() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/derefer_complex_case.rs:+0:11: +0:11
-      let mut _1: std::slice::Iter<i32>;   // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
+      let mut _1: std::slice::Iter<'_, i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
       let mut _2: &[i32; 2];               // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
       let _3: [i32; 2];                    // in scope 0 at $DIR/derefer_complex_case.rs:+1:18: +1:26
-      let mut _4: std::slice::Iter<i32>;   // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
+      let mut _4: std::slice::Iter<'_, i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
       let mut _5: ();                      // in scope 0 at $DIR/derefer_complex_case.rs:+0:1: +2:2
       let _6: ();                          // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
       let mut _7: std::option::Option<&i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
-      let mut _8: &mut std::slice::Iter<i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
+      let mut _8: &mut std::slice::Iter<'_, i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
-      let mut _9: &mut std::slice::Iter<i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
+      let mut _9: &mut std::slice::Iter<'_, i32>; // in scope 0 at $DIR/derefer_complex_case.rs:+1:17: +1:26
       let mut _10: isize;                  // in scope 0 at $DIR/derefer_complex_case.rs:+1:5: +1:40
       let mut _11: !;                      // in scope 0 at $DIR/derefer_complex_case.rs:+1:5: +1:40
       let mut _13: i32;                    // in scope 0 at $DIR/derefer_complex_case.rs:+1:34: +1:37
@@ -53,10 +53,10 @@
           StorageLive(_9);                 // scope 1 at $DIR/derefer_complex_case.rs:+1:17: +1:26
           _9 = &mut _4;                    // scope 1 at $DIR/derefer_complex_case.rs:+1:17: +1:26
           _8 = &mut (*_9);                 // scope 1 at $DIR/derefer_complex_case.rs:+1:17: +1:26
-          _7 = <std::slice::Iter<i32> as Iterator>::next(move _8) -> bb3; // scope 1 at $DIR/derefer_complex_case.rs:+1:17: +1:26
+          _7 = <std::slice::Iter<'_, i32> as Iterator>::next(move _8) -> bb3; // scope 1 at $DIR/derefer_complex_case.rs:+1:17: +1:26
                                            // mir::Constant
                                            // + span: $DIR/derefer_complex_case.rs:6:17: 6:26
-                                           // + literal: Const { ty: for<'r> fn(&'r mut std::slice::Iter<i32>) -> Option<<std::slice::Iter<i32> as Iterator>::Item> {<std::slice::Iter<i32> as Iterator>::next}, val: Value(<ZST>) }
+                                           // + literal: Const { ty: for<'r> fn(&'r mut std::slice::Iter<'_, i32>) -> Option<<std::slice::Iter<'_, i32> as Iterator>::Item> {<std::slice::Iter<'_, i32> as Iterator>::next}, val: Value(<ZST>) }
       }
   
       bb3: {

src/test/mir-opt/early_otherwise_branch_soundness.no_downcast.EarlyOtherwiseBranch.diff

@@ -1,12 +1,12 @@
 - // MIR for `no_downcast` before EarlyOtherwiseBranch
 + // MIR for `no_downcast` after EarlyOtherwiseBranch
   
-  fn no_downcast(_1: &E) -> u32 {
+  fn no_downcast(_1: &E<'_>) -> u32 {
       debug e => _1;                       // in scope 0 at $DIR/early_otherwise_branch_soundness.rs:+0:16: +0:17
       let mut _0: u32;                     // return place in scope 0 at $DIR/early_otherwise_branch_soundness.rs:+0:26: +0:29
       let mut _2: isize;                   // in scope 0 at $DIR/early_otherwise_branch_soundness.rs:+1:20: +1:30
       let mut _3: isize;                   // in scope 0 at $DIR/early_otherwise_branch_soundness.rs:+1:12: +1:31
-      let mut _4: &E;                      // in scope 0 at $DIR/early_otherwise_branch_soundness.rs:+0:16: +0:17
+      let mut _4: &E<'_>;                  // in scope 0 at $DIR/early_otherwise_branch_soundness.rs:+0:16: +0:17
       scope 1 {
       }
   
@@ -16,7 +16,7 @@
       }
   
       bb1: {
-          _4 = deref_copy (((*_1) as Some).0: &E); // scope 1 at $DIR/early_otherwise_branch_soundness.rs:+1:12: +1:31
+          _4 = deref_copy (((*_1) as Some).0: &E<'_>); // scope 1 at $DIR/early_otherwise_branch_soundness.rs:+1:12: +1:31
           _2 = discriminant((*_4));        // scope 1 at $DIR/early_otherwise_branch_soundness.rs:+1:12: +1:31
           switchInt(move _2) -> [1_isize: bb2, otherwise: bb3]; // scope 1 at $DIR/early_otherwise_branch_soundness.rs:+1:12: +1:31
       }

src/test/mir-opt/funky_arms.float_to_exponential_common.ConstProp.diff

@@ -1,24 +1,24 @@
 - // MIR for `float_to_exponential_common` before ConstProp
 + // MIR for `float_to_exponential_common` after ConstProp
   
-  fn float_to_exponential_common(_1: &mut Formatter, _2: &T, _3: bool) -> Result<(), std::fmt::Error> {
+  fn float_to_exponential_common(_1: &mut Formatter<'_>, _2: &T, _3: bool) -> Result<(), std::fmt::Error> {
       debug fmt => _1;                     // in scope 0 at $DIR/funky_arms.rs:+0:35: +0:38
       debug num => _2;                     // in scope 0 at $DIR/funky_arms.rs:+0:60: +0:63
       debug upper => _3;                   // in scope 0 at $DIR/funky_arms.rs:+0:69: +0:74
       let mut _0: std::result::Result<(), std::fmt::Error>; // return place in scope 0 at $DIR/funky_arms.rs:+0:85: +0:91
       let _4: bool;                        // in scope 0 at $DIR/funky_arms.rs:+4:9: +4:19
-      let mut _5: &std::fmt::Formatter;    // in scope 0 at $DIR/funky_arms.rs:+4:22: +4:37
+      let mut _5: &std::fmt::Formatter<'_>; // in scope 0 at $DIR/funky_arms.rs:+4:22: +4:37
       let mut _7: std::option::Option<usize>; // in scope 0 at $DIR/funky_arms.rs:+13:30: +13:45
-      let mut _8: &std::fmt::Formatter;    // in scope 0 at $DIR/funky_arms.rs:+13:30: +13:45
+      let mut _8: &std::fmt::Formatter<'_>; // in scope 0 at $DIR/funky_arms.rs:+13:30: +13:45
       let mut _9: isize;                   // in scope 0 at $DIR/funky_arms.rs:+13:12: +13:27
-      let mut _11: &mut std::fmt::Formatter; // in scope 0 at $DIR/funky_arms.rs:+15:43: +15:46
+      let mut _11: &mut std::fmt::Formatter<'_>; // in scope 0 at $DIR/funky_arms.rs:+15:43: +15:46
       let mut _12: &T;                     // in scope 0 at $DIR/funky_arms.rs:+15:48: +15:51
       let mut _13: core::num::flt2dec::Sign; // in scope 0 at $DIR/funky_arms.rs:+15:53: +15:57
       let mut _14: u32;                    // in scope 0 at $DIR/funky_arms.rs:+15:59: +15:79
       let mut _15: u32;                    // in scope 0 at $DIR/funky_arms.rs:+15:59: +15:75
       let mut _16: usize;                  // in scope 0 at $DIR/funky_arms.rs:+15:59: +15:68
       let mut _17: bool;                   // in scope 0 at $DIR/funky_arms.rs:+15:81: +15:86
-      let mut _18: &mut std::fmt::Formatter; // in scope 0 at $DIR/funky_arms.rs:+17:46: +17:49
+      let mut _18: &mut std::fmt::Formatter<'_>; // in scope 0 at $DIR/funky_arms.rs:+17:46: +17:49
       let mut _19: &T;                     // in scope 0 at $DIR/funky_arms.rs:+17:51: +17:54
       let mut _20: core::num::flt2dec::Sign; // in scope 0 at $DIR/funky_arms.rs:+17:56: +17:60
       let mut _21: bool;                   // in scope 0 at $DIR/funky_arms.rs:+17:62: +17:67
@@ -38,10 +38,10 @@
           StorageLive(_4);                 // scope 0 at $DIR/funky_arms.rs:+4:9: +4:19
           StorageLive(_5);                 // scope 0 at $DIR/funky_arms.rs:+4:22: +4:37
           _5 = &(*_1);                     // scope 0 at $DIR/funky_arms.rs:+4:22: +4:37
-          _4 = Formatter::sign_plus(move _5) -> bb1; // scope 0 at $DIR/funky_arms.rs:+4:22: +4:37
+          _4 = Formatter::<'_>::sign_plus(move _5) -> bb1; // scope 0 at $DIR/funky_arms.rs:+4:22: +4:37
                                            // mir::Constant
                                            // + span: $DIR/funky_arms.rs:15:26: 15:35
-                                           // + literal: Const { ty: for<'r> fn(&'r Formatter) -> bool {Formatter::sign_plus}, val: Value(<ZST>) }
+                                           // + literal: Const { ty: for<'r> fn(&'r Formatter<'_>) -> bool {Formatter::<'_>::sign_plus}, val: Value(<ZST>) }
       }
   
       bb1: {
@@ -66,10 +66,10 @@
           StorageLive(_7);                 // scope 3 at $DIR/funky_arms.rs:+13:30: +13:45
           StorageLive(_8);                 // scope 3 at $DIR/funky_arms.rs:+13:30: +13:45
           _8 = &(*_1);                     // scope 3 at $DIR/funky_arms.rs:+13:30: +13:45
-          _7 = Formatter::precision(move _8) -> bb5; // scope 3 at $DIR/funky_arms.rs:+13:30: +13:45
+          _7 = Formatter::<'_>::precision(move _8) -> bb5; // scope 3 at $DIR/funky_arms.rs:+13:30: +13:45
                                            // mir::Constant
                                            // + span: $DIR/funky_arms.rs:24:34: 24:43
-                                           // + literal: Const { ty: for<'r> fn(&'r Formatter) -> Option<usize> {Formatter::precision}, val: Value(<ZST>) }
+                                           // + literal: Const { ty: for<'r> fn(&'r Formatter<'_>) -> Option<usize> {Formatter::<'_>::precision}, val: Value(<ZST>) }
       }
   
       bb5: {

src/test/mir-opt/issue_73223.main.SimplifyArmIdentity.diff

@@ -25,7 +25,7 @@
       let _24: &i32;                       // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
       let mut _25: &i32;                   // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
       let _26: &i32;                       // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-      let mut _27: std::option::Option<std::fmt::Arguments>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+      let mut _27: std::option::Option<std::fmt::Arguments<'_>>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
       scope 1 {
           debug split => _1;               // in scope 1 at $DIR/issue-73223.rs:+1:9: +1:14
           let _6: std::option::Option<i32>; // in scope 1 at $DIR/issue-73223.rs:+6:9: +6:14

src/test/mir-opt/issue_99325.main.mir_map.0.mir

@@ -26,7 +26,7 @@ fn main() -> () {
     let _19: &&[u8];                     // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let mut _20: &&[u8; 4];              // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let _21: &&[u8; 4];                  // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-    let mut _22: std::option::Option<std::fmt::Arguments>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+    let mut _22: std::option::Option<std::fmt::Arguments<'_>>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let _23: ();                         // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let mut _24: (&&[u8], &&[u8; 4]);    // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let mut _25: &&[u8];                 // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
@@ -46,7 +46,7 @@ fn main() -> () {
     let _40: &&[u8];                     // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let mut _41: &&[u8; 4];              // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let _42: &&[u8; 4];                  // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-    let mut _43: std::option::Option<std::fmt::Arguments>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+    let mut _43: std::option::Option<std::fmt::Arguments<'_>>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     scope 1 {
         debug left_val => _8;            // in scope 1 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         debug right_val => _9;           // in scope 1 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
@@ -128,7 +128,7 @@ fn main() -> () {
         _21 = &(*_9);                    // scope 2 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         _20 = &(*_21);                   // scope 2 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         StorageLive(_22);                // scope 2 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-        _22 = Option::<Arguments>::None; // scope 2 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+        _22 = Option::<Arguments<'_>>::None; // scope 2 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         _16 = core::panicking::assert_failed::<&[u8], &[u8; 4]>(move _17, move _18, move _20, move _22) -> bb19; // scope 2 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
                                          // mir::Constant
                                          // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
@@ -237,7 +237,7 @@ fn main() -> () {
         _42 = &(*_30);                   // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         _41 = &(*_42);                   // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         StorageLive(_43);                // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-        _43 = Option::<Arguments>::None; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+        _43 = Option::<Arguments<'_>>::None; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
         _37 = core::panicking::assert_failed::<&[u8], &[u8; 4]>(move _38, move _39, move _41, move _43) -> bb19; // scope 4 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
                                          // mir::Constant
                                          // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL

src/test/mir-opt/retag.array_casts.SimplifyCfg-elaborate-drops.after.mir

@@ -29,7 +29,7 @@ fn array_casts() -> () {
     let _31: &usize;                     // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let mut _32: &usize;                 // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     let _33: &usize;                     // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
-    let mut _34: std::option::Option<std::fmt::Arguments>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
+    let mut _34: std::option::Option<std::fmt::Arguments<'_>>; // in scope 0 at $SRC_DIR/core/src/macros/mod.rs:LL:COL
     scope 1 {
         debug x => _1;                   // in scope 1 at $DIR/retag.rs:+1:9: +1:14
         let _2: *mut usize;              // in scope 1 at $DIR/retag.rs:+2:9: +2:10

src/test/ui/const-generics/issues/issue-83765.stderr

@@ -1,16 +1,16 @@
-error[E0391]: cycle detected when resolving instance `<LazyUpdim<T, { T::DIM }, DIM> as TensorDimension>::DIM`
+error[E0391]: cycle detected when resolving instance `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>::DIM`
   --> $DIR/issue-83765.rs:5:5
    |
 LL |     const DIM: usize;
    |     ^^^^^^^^^^^^^^^^
    |
-note: ...which requires computing candidate for `<LazyUpdim<T, { T::DIM }, DIM> as TensorDimension>`...
+note: ...which requires computing candidate for `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>`...
   --> $DIR/issue-83765.rs:4:1
    |
 LL | trait TensorDimension {
    | ^^^^^^^^^^^^^^^^^^^^^
-   = note: ...which again requires resolving instance `<LazyUpdim<T, { T::DIM }, DIM> as TensorDimension>::DIM`, completing the cycle
+   = note: ...which again requires resolving instance `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>::DIM`, completing the cycle
-note: cycle used when computing candidate for `<LazyUpdim<T, { T::DIM }, DIM> as TensorDimension>`
+note: cycle used when computing candidate for `<LazyUpdim<'_, T, { T::DIM }, DIM> as TensorDimension>`
   --> $DIR/issue-83765.rs:4:1
    |
 LL | trait TensorDimension {

src/test/ui/const-ptr/forbidden_slices.64bit.stderr

@@ -5,7 +5,7 @@ LL |         &*ptr::slice_from_raw_parts(data, len)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |         |
    |         dereferencing pointer failed: null pointer is a dangling pointer (it has no provenance)
-   |         inside `std::slice::from_raw_parts::<u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |         inside `std::slice::from_raw_parts::<'_, u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:18:34
    |
@@ -19,7 +19,7 @@ LL |         &*ptr::slice_from_raw_parts(data, len)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |         |
    |         dereferencing pointer failed: null pointer is a dangling pointer (it has no provenance)
-   |         inside `std::slice::from_raw_parts::<()>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |         inside `std::slice::from_raw_parts::<'_, ()>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:19:33
    |
@@ -33,7 +33,7 @@ LL |         &*ptr::slice_from_raw_parts(data, len)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |         |
    |         dereferencing pointer failed: ALLOC_ID has size 4, so pointer to 8 bytes starting at offset 0 is out-of-bounds
-   |         inside `std::slice::from_raw_parts::<u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |         inside `std::slice::from_raw_parts::<'_, u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:22:34
    |
@@ -92,7 +92,7 @@ LL |         &*ptr::slice_from_raw_parts(data, len)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |         |
    |         dereferencing pointer failed: ALLOC_ID has size 8, so pointer to 8 bytes starting at offset 1 is out-of-bounds
-   |         inside `std::slice::from_raw_parts::<u64>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |         inside `std::slice::from_raw_parts::<'_, u64>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:43:5
    |
@@ -111,7 +111,7 @@ LL |         unsafe { intrinsics::ptr_offset_from_unsigned(self, origin) }
   ::: $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
 LL |     unsafe { from_raw_parts(range.start, range.end.sub_ptr(range.start)) }
-   |                                          ------------------------------ inside `from_ptr_range::<u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |                                          ------------------------------ inside `from_ptr_range::<'_, u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:46:34
    |
@@ -130,7 +130,7 @@ LL |         assert!(0 < pointee_size && pointee_size <= isize::MAX as usize);
   ::: $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
 LL |     unsafe { from_raw_parts(range.start, range.end.sub_ptr(range.start)) }
-   |                                          ------------------------------ inside `from_ptr_range::<()>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |                                          ------------------------------ inside `from_ptr_range::<'_, ()>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:47:33
    |
@@ -230,7 +230,7 @@ LL |         unsafe { intrinsics::ptr_offset_from_unsigned(self, origin) }
   ::: $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
 LL |     unsafe { from_raw_parts(range.start, range.end.sub_ptr(range.start)) }
-   |                                          ------------------------------ inside `from_ptr_range::<u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |                                          ------------------------------ inside `from_ptr_range::<'_, u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:79:34
    |
@@ -249,7 +249,7 @@ LL |         unsafe { intrinsics::ptr_offset_from_unsigned(self, origin) }
   ::: $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
 LL |     unsafe { from_raw_parts(range.start, range.end.sub_ptr(range.start)) }
-   |                                          ------------------------------ inside `from_ptr_range::<u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
+   |                                          ------------------------------ inside `from_ptr_range::<'_, u32>` at $SRC_DIR/core/src/slice/raw.rs:LL:COL
    |
   ::: $DIR/forbidden_slices.rs:80:35
    |

src/test/ui/issues/issue-21174.stderr

@@ -4,8 +4,8 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
 LL |     let new: T::B = unsafe { std::mem::transmute(value) };
    |                              ^^^^^^^^^^^^^^^^^^^
    |
-   = note: source type: `<T as Trait>::A` (this type does not have a fixed size)
+   = note: source type: `<T as Trait<'_>>::A` (this type does not have a fixed size)
-   = note: target type: `<T as Trait>::B` (this type does not have a fixed size)
+   = note: target type: `<T as Trait<'_>>::B` (this type does not have a fixed size)
 
 error: aborting due to previous error
 

src/test/ui/polymorphization/predicates.stderr

@@ -41,7 +41,7 @@ error: item has unused generic parameters
 LL | fn bar<I>() {
    |    ^^^ - generic parameter `I` is unused
 
-note: the above error was encountered while instantiating `fn foo::<std::slice::Iter<u32>, T>`
+note: the above error was encountered while instantiating `fn foo::<std::slice::Iter<'_, u32>, T>`
   --> $DIR/predicates.rs:86:5
    |
 LL |     foo(x.iter());

src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr

@@ -6,7 +6,7 @@ LL |     let Ok(x) = res;
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
-note: `Result<u32, &R>` defined here
+note: `Result<u32, &R<'_>>` defined here
   --> $SRC_DIR/core/src/result.rs:LL:COL
    |
 LL | pub enum Result<T, E> {
@@ -14,7 +14,7 @@ LL | pub enum Result<T, E> {
 ...
 LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
    |     ^^^ not covered
-   = note: the matched value is of type `Result<u32, &R>`
+   = note: the matched value is of type `Result<u32, &R<'_>>`
 help: you might want to use `if let` to ignore the variant that isn't matched
    |
 LL |     let x = if let Ok(x) = res { x } else { todo!() };

src/test/ui/specialization/issue-38091-2.stderr

@@ -10,7 +10,7 @@ LL | #![feature(specialization)]
 
 error[E0275]: overflow evaluating the requirement `i32: Check`
    |
-note: required for `i32` to implement `Iterate`
+note: required for `i32` to implement `Iterate<'_>`
   --> $DIR/issue-38091-2.rs:11:13
    |
 LL | impl<'a, T> Iterate<'a> for T

src/test/ui/transmute/main.stderr

@@ -4,7 +4,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
 LL |     transmute(x)
    |     ^^^^^^^^^
    |
-   = note: `<C as TypeConstructor>::T` does not have a fixed size
+   = note: `<C as TypeConstructor<'_>>::T` does not have a fixed size
 
 error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
   --> $DIR/main.rs:17:17