Rollup merge of #101700 - compiler-errors:deletion-span, r=davidtwco

A `SubstitutionPart` is not considered a deletion if it replaces nothing with nothing

Fixes #101689

21 files changed, 159 insertions, 220 deletions

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 1d260f7cafc..66fbb8f1213 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -1704,7 +1704,7 @@ impl EmitterWriter {
         {
             notice_capitalization |= only_capitalization;
 
-            let has_deletion = parts.iter().any(|p| p.is_deletion());
+            let has_deletion = parts.iter().any(|p| p.is_deletion(sm));
             let is_multiline = complete.lines().count() > 1;
 
             if let Some(span) = span.primary_span() {
@@ -1880,16 +1880,23 @@ impl EmitterWriter {
                     let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
                     let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
 
+                    // If this addition is _only_ whitespace, then don't trim it,
+                    // or else we're just not rendering anything.
+                    let is_whitespace_addition = part.snippet.trim().is_empty();
+
                     // Do not underline the leading...
-                    let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
+                    let start = if is_whitespace_addition {
+                        0
+                    } else {
+                        part.snippet.len().saturating_sub(part.snippet.trim_start().len())
+                    };
                     // ...or trailing spaces. Account for substitutions containing unicode
                     // characters.
-                    let sub_len: usize = part
-                        .snippet
-                        .trim()
-                        .chars()
-                        .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
-                        .sum();
+                    let sub_len: usize =
+                        if is_whitespace_addition { &part.snippet } else { part.snippet.trim() }
+                            .chars()
+                            .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
+                            .sum();
 
                     let offset: isize = offsets
                         .iter()
@@ -2130,7 +2137,7 @@ impl EmitterWriter {
     }
 }
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 enum DisplaySuggestion {
     Underline,
     Diff,
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index fb7ae6f99cf..888128f3f74 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -150,21 +150,20 @@ pub struct SubstitutionHighlight {
 
 impl SubstitutionPart {
     pub fn is_addition(&self, sm: &SourceMap) -> bool {
-        !self.snippet.is_empty()
-            && sm
-                .span_to_snippet(self.span)
-                .map_or(self.span.is_empty(), |snippet| snippet.trim().is_empty())
+        !self.snippet.is_empty() && !self.replaces_meaningful_content(sm)
     }
 
-    pub fn is_deletion(&self) -> bool {
-        self.snippet.trim().is_empty()
+    pub fn is_deletion(&self, sm: &SourceMap) -> bool {
+        self.snippet.trim().is_empty() && self.replaces_meaningful_content(sm)
     }
 
     pub fn is_replacement(&self, sm: &SourceMap) -> bool {
-        !self.snippet.is_empty()
-            && sm
-                .span_to_snippet(self.span)
-                .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty())
+        !self.snippet.is_empty() && self.replaces_meaningful_content(sm)
+    }
+
+    fn replaces_meaningful_content(&self, sm: &SourceMap) -> bool {
+        sm.span_to_snippet(self.span)
+            .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty())
     }
 }
 
diff --git a/src/test/ui/dyn-keyword/dyn-2018-edition-lint.stderr b/src/test/ui/dyn-keyword/dyn-2018-edition-lint.stderr
index 34699bb2658..e7db68693c0 100644
--- a/src/test/ui/dyn-keyword/dyn-2018-edition-lint.stderr
+++ b/src/test/ui/dyn-keyword/dyn-2018-edition-lint.stderr
@@ -13,9 +13,8 @@ LL | #[deny(bare_trait_objects)]
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
-   |
+LL | fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+   |                 +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:35
@@ -27,9 +26,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
-   |
+LL | fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+   |                                   +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:17:14
@@ -41,9 +39,8 @@ LL |     let _x: &SomeTrait = todo!();
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     let _x: &SomeTrait = todo!();
-LL +     let _x: &dyn SomeTrait = todo!();
-   |
+LL |     let _x: &dyn SomeTrait = todo!();
+   |              +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:17
@@ -55,9 +52,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
-   |
+LL | fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+   |                 +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:17
@@ -69,9 +65,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
-   |
+LL | fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+   |                 +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:35
@@ -83,9 +78,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
-   |
+LL | fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+   |                                   +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/dyn-2018-edition-lint.rs:4:35
@@ -97,9 +91,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
-   |
+LL | fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+   |                                   +++
 
 error: aborting due to 7 previous errors
 
diff --git a/src/test/ui/dyn-keyword/dyn-2021-edition-error.stderr b/src/test/ui/dyn-keyword/dyn-2021-edition-error.stderr
index 9e212c77dc7..08ee77116f0 100644
--- a/src/test/ui/dyn-keyword/dyn-2021-edition-error.stderr
+++ b/src/test/ui/dyn-keyword/dyn-2021-edition-error.stderr
@@ -6,9 +6,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    |
 help: add `dyn` keyword before this trait
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
-   |
+LL | fn function(x: &dyn SomeTrait, y: Box<SomeTrait>) {
+   |                 +++
 
 error[E0782]: trait objects must include the `dyn` keyword
   --> $DIR/dyn-2021-edition-error.rs:3:35
@@ -18,9 +17,8 @@ LL | fn function(x: &SomeTrait, y: Box<SomeTrait>) {
    |
 help: add `dyn` keyword before this trait
    |
-LL - fn function(x: &SomeTrait, y: Box<SomeTrait>) {
-LL + fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
-   |
+LL | fn function(x: &SomeTrait, y: Box<dyn SomeTrait>) {
+   |                                   +++
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/dyn-keyword/dyn-angle-brackets.stderr b/src/test/ui/dyn-keyword/dyn-angle-brackets.stderr
index 9bc603fba54..261c2d5742f 100644
--- a/src/test/ui/dyn-keyword/dyn-angle-brackets.stderr
+++ b/src/test/ui/dyn-keyword/dyn-angle-brackets.stderr
@@ -13,9 +13,8 @@ LL | #![deny(bare_trait_objects)]
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -         <fmt::Debug>::fmt(self, f)
-LL +         <dyn fmt::Debug>::fmt(self, f)
-   |
+LL |         <dyn fmt::Debug>::fmt(self, f)
+   |          +++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/impl-trait/generic-with-implicit-hrtb-without-dyn.edition2021.stderr b/src/test/ui/impl-trait/generic-with-implicit-hrtb-without-dyn.edition2021.stderr
index c01c33a8931..8f409227324 100644
--- a/src/test/ui/impl-trait/generic-with-implicit-hrtb-without-dyn.edition2021.stderr
+++ b/src/test/ui/impl-trait/generic-with-implicit-hrtb-without-dyn.edition2021.stderr
@@ -6,9 +6,8 @@ LL | fn ice() -> impl AsRef<Fn(&())> {
    |
 help: add `dyn` keyword before this trait
    |
-LL - fn ice() -> impl AsRef<Fn(&())> {
-LL + fn ice() -> impl AsRef<dyn Fn(&())> {
-   |
+LL | fn ice() -> impl AsRef<dyn Fn(&())> {
+   |                        +++
 
 error[E0277]: the trait bound `(): AsRef<(dyn for<'r> Fn(&'r ()) + 'static)>` is not satisfied
   --> $DIR/generic-with-implicit-hrtb-without-dyn.rs:6:13
diff --git a/src/test/ui/issues/issue-86756.stderr b/src/test/ui/issues/issue-86756.stderr
index 399c940ca19..b26c1834d84 100644
--- a/src/test/ui/issues/issue-86756.stderr
+++ b/src/test/ui/issues/issue-86756.stderr
@@ -25,9 +25,8 @@ LL |     eq::<dyn, Foo>
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     eq::<dyn, Foo>
-LL +     eq::<dyn, dyn Foo>
-   |
+LL |     eq::<dyn, dyn Foo>
+   |               +++
 
 error[E0107]: missing generics for trait `Foo`
   --> $DIR/issue-86756.rs:5:15
diff --git a/src/test/ui/lint/force-warn/allowed-group-warn-by-default-lint.stderr b/src/test/ui/lint/force-warn/allowed-group-warn-by-default-lint.stderr
index 8d826bd1457..94d81c3aa71 100644
--- a/src/test/ui/lint/force-warn/allowed-group-warn-by-default-lint.stderr
+++ b/src/test/ui/lint/force-warn/allowed-group-warn-by-default-lint.stderr
@@ -9,9 +9,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/allowed-group-warn-by-default-lint.rs:10:25
@@ -23,9 +22,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/allowed-group-warn-by-default-lint.rs:10:25
@@ -37,9 +35,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: 3 warnings emitted
 
diff --git a/src/test/ui/lint/force-warn/cap-lints-allow.stderr b/src/test/ui/lint/force-warn/cap-lints-allow.stderr
index 978270872c4..7f0fd8530e2 100644
--- a/src/test/ui/lint/force-warn/cap-lints-allow.stderr
+++ b/src/test/ui/lint/force-warn/cap-lints-allow.stderr
@@ -9,9 +9,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/cap-lints-allow.rs:8:25
@@ -23,9 +22,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/cap-lints-allow.rs:8:25
@@ -37,9 +35,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: 3 warnings emitted
 
diff --git a/src/test/ui/lint/force-warn/lint-group-allowed-cli-warn-by-default-lint.stderr b/src/test/ui/lint/force-warn/lint-group-allowed-cli-warn-by-default-lint.stderr
index 6e67ebf2747..eb2bca7b84d 100644
--- a/src/test/ui/lint/force-warn/lint-group-allowed-cli-warn-by-default-lint.stderr
+++ b/src/test/ui/lint/force-warn/lint-group-allowed-cli-warn-by-default-lint.stderr
@@ -9,9 +9,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-cli-warn-by-default-lint.rs:8:25
@@ -23,9 +22,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-cli-warn-by-default-lint.rs:8:25
@@ -37,9 +35,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: 3 warnings emitted
 
diff --git a/src/test/ui/lint/force-warn/lint-group-allowed-lint-group.stderr b/src/test/ui/lint/force-warn/lint-group-allowed-lint-group.stderr
index c5dea84b8f3..ed01937a57b 100644
--- a/src/test/ui/lint/force-warn/lint-group-allowed-lint-group.stderr
+++ b/src/test/ui/lint/force-warn/lint-group-allowed-lint-group.stderr
@@ -9,9 +9,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-lint-group.rs:10:25
@@ -23,9 +22,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-lint-group.rs:10:25
@@ -37,9 +35,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: 3 warnings emitted
 
diff --git a/src/test/ui/lint/force-warn/lint-group-allowed-warn-by-default-lint.stderr b/src/test/ui/lint/force-warn/lint-group-allowed-warn-by-default-lint.stderr
index acd0c503d9c..8db7c12757b 100644
--- a/src/test/ui/lint/force-warn/lint-group-allowed-warn-by-default-lint.stderr
+++ b/src/test/ui/lint/force-warn/lint-group-allowed-warn-by-default-lint.stderr
@@ -9,9 +9,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-warn-by-default-lint.rs:10:25
@@ -23,9 +22,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/lint-group-allowed-warn-by-default-lint.rs:10:25
@@ -37,9 +35,8 @@ LL | pub fn function(_x: Box<SomeTrait>) {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub fn function(_x: Box<SomeTrait>) {}
-LL + pub fn function(_x: Box<dyn SomeTrait>) {}
-   |
+LL | pub fn function(_x: Box<dyn SomeTrait>) {}
+   |                         +++
 
 warning: 3 warnings emitted
 
diff --git a/src/test/ui/parser/increment-notfixed.stderr b/src/test/ui/parser/increment-notfixed.stderr
index 352d98cf82e..ae55ae06714 100644
--- a/src/test/ui/parser/increment-notfixed.stderr
+++ b/src/test/ui/parser/increment-notfixed.stderr
@@ -8,9 +8,8 @@ help: use `+= 1` instead
    |
 LL |     { let tmp = i; i += 1; tmp };
    |     +++++++++++  ~~~~~~~~~~~~~~~
-LL -     i++;
-LL +     i += 1;
-   |
+LL |     i += 1;
+   |       ~~~~
 
 error: Rust has no postfix increment operator
   --> $DIR/increment-notfixed.rs:17:12
@@ -24,9 +23,8 @@ help: use `+= 1` instead
    |
 LL |     while { let tmp = i; i += 1; tmp } < 5 {
    |           +++++++++++  ~~~~~~~~~~~~~~~
-LL -     while i++ < 5 {
-LL +     while i += 1 < 5 {
-   |
+LL |     while i += 1 < 5 {
+   |             ~~~~
 
 error: Rust has no postfix increment operator
   --> $DIR/increment-notfixed.rs:25:8
@@ -38,9 +36,8 @@ help: use `+= 1` instead
    |
 LL |     { let tmp_ = tmp; tmp += 1; tmp_ };
    |     ++++++++++++    ~~~~~~~~~~~~~~~~~~
-LL -     tmp++;
-LL +     tmp += 1;
-   |
+LL |     tmp += 1;
+   |         ~~~~
 
 error: Rust has no postfix increment operator
   --> $DIR/increment-notfixed.rs:31:14
@@ -54,9 +51,8 @@ help: use `+= 1` instead
    |
 LL |     while { let tmp_ = tmp; tmp += 1; tmp_ } < 5 {
    |           ++++++++++++    ~~~~~~~~~~~~~~~~~~
-LL -     while tmp++ < 5 {
-LL +     while tmp += 1 < 5 {
-   |
+LL |     while tmp += 1 < 5 {
+   |               ~~~~
 
 error: Rust has no postfix increment operator
   --> $DIR/increment-notfixed.rs:39:16
@@ -68,9 +64,8 @@ help: use `+= 1` instead
    |
 LL |     { let tmp = foo.bar.qux; foo.bar.qux += 1; tmp };
    |     +++++++++++            ~~~~~~~~~~~~~~~~~~~~~~~~~
-LL -     foo.bar.qux++;
-LL +     foo.bar.qux += 1;
-   |
+LL |     foo.bar.qux += 1;
+   |                 ~~~~
 
 error: Rust has no postfix increment operator
   --> $DIR/increment-notfixed.rs:49:10
@@ -82,9 +77,8 @@ help: use `+= 1` instead
    |
 LL |     { let tmp = s.tmp; s.tmp += 1; tmp };
    |     +++++++++++      ~~~~~~~~~~~~~~~~~~~
-LL -     s.tmp++;
-LL +     s.tmp += 1;
-   |
+LL |     s.tmp += 1;
+   |           ~~~~
 
 error: Rust has no prefix increment operator
   --> $DIR/increment-notfixed.rs:56:5
diff --git a/src/test/ui/parser/trait-object-trait-parens.stderr b/src/test/ui/parser/trait-object-trait-parens.stderr
index 7ee965bd2ba..823f75bfac8 100644
--- a/src/test/ui/parser/trait-object-trait-parens.stderr
+++ b/src/test/ui/parser/trait-object-trait-parens.stderr
@@ -27,9 +27,8 @@ LL |     let _: Box<(Obj) + (?Sized) + (for<'a> Trait<'a>)>;
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     let _: Box<(Obj) + (?Sized) + (for<'a> Trait<'a>)>;
-LL +     let _: Box<dyn (Obj) + (?Sized) + (for<'a> Trait<'a>)>;
-   |
+LL |     let _: Box<dyn (Obj) + (?Sized) + (for<'a> Trait<'a>)>;
+   |                +++
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
   --> $DIR/trait-object-trait-parens.rs:8:35
@@ -52,9 +51,8 @@ LL |     let _: Box<?Sized + (for<'a> Trait<'a>) + (Obj)>;
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     let _: Box<?Sized + (for<'a> Trait<'a>) + (Obj)>;
-LL +     let _: Box<dyn ?Sized + (for<'a> Trait<'a>) + (Obj)>;
-   |
+LL |     let _: Box<dyn ?Sized + (for<'a> Trait<'a>) + (Obj)>;
+   |                +++
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
   --> $DIR/trait-object-trait-parens.rs:13:47
@@ -77,9 +75,8 @@ LL |     let _: Box<for<'a> Trait<'a> + (Obj) + (?Sized)>;
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     let _: Box<for<'a> Trait<'a> + (Obj) + (?Sized)>;
-LL +     let _: Box<dyn for<'a> Trait<'a> + (Obj) + (?Sized)>;
-   |
+LL |     let _: Box<dyn for<'a> Trait<'a> + (Obj) + (?Sized)>;
+   |                +++
 
 error[E0225]: only auto traits can be used as additional traits in a trait object
   --> $DIR/trait-object-trait-parens.rs:18:36
diff --git a/src/test/ui/rust-2021/reserved-prefixes-migration.stderr b/src/test/ui/rust-2021/reserved-prefixes-migration.stderr
index 647a9f39312..c6bc082cf18 100644
--- a/src/test/ui/rust-2021/reserved-prefixes-migration.stderr
+++ b/src/test/ui/rust-2021/reserved-prefixes-migration.stderr
@@ -13,9 +13,8 @@ LL | #![warn(rust_2021_prefixes_incompatible_syntax)]
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/reserving-syntax.html>
 help: insert whitespace here to avoid this being parsed as a prefix in Rust 2021
    |
-LL -     m2!(z"hey");
-LL +     m2!(z "hey");
-   |
+LL |     m2!(z "hey");
+   |          +
 
 warning: prefix `prefix` is unknown
   --> $DIR/reserved-prefixes-migration.rs:19:9
@@ -27,9 +26,8 @@ LL |     m2!(prefix"hey");
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/reserving-syntax.html>
 help: insert whitespace here to avoid this being parsed as a prefix in Rust 2021
    |
-LL -     m2!(prefix"hey");
-LL +     m2!(prefix "hey");
-   |
+LL |     m2!(prefix "hey");
+   |               +
 
 warning: prefix `hey` is unknown
   --> $DIR/reserved-prefixes-migration.rs:22:9
@@ -41,9 +39,8 @@ LL |     m3!(hey#123);
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/reserving-syntax.html>
 help: insert whitespace here to avoid this being parsed as a prefix in Rust 2021
    |
-LL -     m3!(hey#123);
-LL +     m3!(hey #123);
-   |
+LL |     m3!(hey #123);
+   |            +
 
 warning: prefix `hey` is unknown
   --> $DIR/reserved-prefixes-migration.rs:25:9
@@ -55,9 +52,8 @@ LL |     m3!(hey#hey);
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/reserving-syntax.html>
 help: insert whitespace here to avoid this being parsed as a prefix in Rust 2021
    |
-LL -     m3!(hey#hey);
-LL +     m3!(hey #hey);
-   |
+LL |     m3!(hey #hey);
+   |            +
 
 warning: prefix `kind` is unknown
   --> $DIR/reserved-prefixes-migration.rs:35:14
@@ -69,9 +65,8 @@ LL |     #name = #kind#value
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/reserving-syntax.html>
 help: insert whitespace here to avoid this being parsed as a prefix in Rust 2021
    |
-LL -     #name = #kind#value
-LL +     #name = #kind #value
-   |
+LL |     #name = #kind #value
+   |                  +
 
 warning: 5 warnings emitted
 
diff --git a/src/test/ui/rust-2021/reserved-prefixes.stderr b/src/test/ui/rust-2021/reserved-prefixes.stderr
index df31aee66fe..807d6d98bd3 100644
--- a/src/test/ui/rust-2021/reserved-prefixes.stderr
+++ b/src/test/ui/rust-2021/reserved-prefixes.stderr
@@ -7,9 +7,8 @@ LL |     demo3!(foo#bar);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo3!(foo#bar);
-LL +     demo3!(foo #bar);
-   |
+LL |     demo3!(foo #bar);
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:17:12
@@ -20,9 +19,8 @@ LL |     demo2!(foo"bar");
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo2!(foo"bar");
-LL +     demo2!(foo "bar");
-   |
+LL |     demo2!(foo "bar");
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:18:12
@@ -33,9 +31,8 @@ LL |     demo2!(foo'b');
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo2!(foo'b');
-LL +     demo2!(foo 'b');
-   |
+LL |     demo2!(foo 'b');
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:20:12
@@ -46,9 +43,8 @@ LL |     demo2!(foo'b);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo2!(foo'b);
-LL +     demo2!(foo 'b);
-   |
+LL |     demo2!(foo 'b);
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:21:12
@@ -59,9 +55,8 @@ LL |     demo3!(foo# bar);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo3!(foo# bar);
-LL +     demo3!(foo # bar);
-   |
+LL |     demo3!(foo # bar);
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:22:12
@@ -72,9 +67,8 @@ LL |     demo4!(foo#! bar);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo4!(foo#! bar);
-LL +     demo4!(foo #! bar);
-   |
+LL |     demo4!(foo #! bar);
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:23:12
@@ -85,9 +79,8 @@ LL |     demo4!(foo## bar);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo4!(foo## bar);
-LL +     demo4!(foo ## bar);
-   |
+LL |     demo4!(foo ## bar);
+   |               +
 
 error: prefix `foo` is unknown
   --> $DIR/reserved-prefixes.rs:25:12
@@ -98,9 +91,8 @@ LL |     demo4!(foo#bar#);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo4!(foo#bar#);
-LL +     demo4!(foo #bar#);
-   |
+LL |     demo4!(foo #bar#);
+   |               +
 
 error: prefix `bar` is unknown
   --> $DIR/reserved-prefixes.rs:25:16
@@ -111,9 +103,8 @@ LL |     demo4!(foo#bar#);
    = note: prefixed identifiers and literals are reserved since Rust 2021
 help: consider inserting whitespace here
    |
-LL -     demo4!(foo#bar#);
-LL +     demo4!(foo#bar #);
-   |
+LL |     demo4!(foo#bar #);
+   |                   +
 
 error: aborting due to 9 previous errors
 
diff --git a/src/test/ui/suggestions/issue-61963.stderr b/src/test/ui/suggestions/issue-61963.stderr
index c0d776e59ab..a788cab6e4e 100644
--- a/src/test/ui/suggestions/issue-61963.stderr
+++ b/src/test/ui/suggestions/issue-61963.stderr
@@ -13,9 +13,8 @@ LL | #![deny(bare_trait_objects)]
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     bar: Box<Bar>,
-LL +     bar: Box<dyn Bar>,
-   |
+LL |     bar: Box<dyn Bar>,
+   |              +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:18:1
@@ -27,9 +26,8 @@ LL | pub struct Foo {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub struct Foo {
-LL + dyn pub struct Foo {
-   |
+LL | dyn pub struct Foo {
+   | +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:28:14
@@ -41,9 +39,8 @@ LL |     bar: Box<Bar>,
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     bar: Box<Bar>,
-LL +     bar: Box<dyn Bar>,
-   |
+LL |     bar: Box<dyn Bar>,
+   |              +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:28:14
@@ -55,9 +52,8 @@ LL |     bar: Box<Bar>,
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL -     bar: Box<Bar>,
-LL +     bar: Box<dyn Bar>,
-   |
+LL |     bar: Box<dyn Bar>,
+   |              +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:18:1
@@ -69,9 +65,8 @@ LL | pub struct Foo {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub struct Foo {
-LL + dyn pub struct Foo {
-   |
+LL | dyn pub struct Foo {
+   | +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:18:1
@@ -83,9 +78,8 @@ LL | pub struct Foo {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub struct Foo {
-LL + dyn pub struct Foo {
-   |
+LL | dyn pub struct Foo {
+   | +++
 
 error: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-61963.rs:18:1
@@ -97,9 +91,8 @@ LL | pub struct Foo {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - pub struct Foo {
-LL + dyn pub struct Foo {
-   |
+LL | dyn pub struct Foo {
+   | +++
 
 error: aborting due to 7 previous errors
 
diff --git a/src/test/ui/suggestions/suggest-blanket-impl-local-trait.stderr b/src/test/ui/suggestions/suggest-blanket-impl-local-trait.stderr
index d739a8272f1..398caa98b84 100644
--- a/src/test/ui/suggestions/suggest-blanket-impl-local-trait.stderr
+++ b/src/test/ui/suggestions/suggest-blanket-impl-local-trait.stderr
@@ -6,9 +6,8 @@ LL | impl LocalTraitTwo for LocalTraitOne {}
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl LocalTraitTwo for LocalTraitOne {}
-LL + impl LocalTraitTwo for dyn LocalTraitOne {}
-   |
+LL | impl LocalTraitTwo for dyn LocalTraitOne {}
+   |                        +++
 help: alternatively use a blanket implementation to implement `LocalTraitTwo` for all types that also implement `LocalTraitOne`
    |
 LL | impl<T: LocalTraitOne> LocalTraitTwo for T {}
@@ -22,9 +21,8 @@ LL | impl fmt::Display for LocalTraitOne {
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl fmt::Display for LocalTraitOne {
-LL + impl fmt::Display for dyn LocalTraitOne {
-   |
+LL | impl fmt::Display for dyn LocalTraitOne {
+   |                       +++
 
 error[E0782]: trait objects must include the `dyn` keyword
   --> $DIR/suggest-blanket-impl-local-trait.rs:26:23
@@ -34,9 +32,8 @@ LL | impl fmt::Display for LocalTraitTwo + Send {
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl fmt::Display for LocalTraitTwo + Send {
-LL + impl fmt::Display for dyn LocalTraitTwo + Send {
-   |
+LL | impl fmt::Display for dyn LocalTraitTwo + Send {
+   |                       +++
 
 error[E0782]: trait objects must include the `dyn` keyword
   --> $DIR/suggest-blanket-impl-local-trait.rs:34:24
@@ -46,9 +43,8 @@ LL | impl LocalTraitOne for fmt::Display {}
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl LocalTraitOne for fmt::Display {}
-LL + impl LocalTraitOne for dyn fmt::Display {}
-   |
+LL | impl LocalTraitOne for dyn fmt::Display {}
+   |                        +++
 help: alternatively use a blanket implementation to implement `LocalTraitOne` for all types that also implement `fmt::Display`
    |
 LL | impl<T: fmt::Display> LocalTraitOne for T {}
@@ -62,9 +58,8 @@ LL | impl LocalTraitOne for fmt::Display + Send {}
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl LocalTraitOne for fmt::Display + Send {}
-LL + impl LocalTraitOne for dyn fmt::Display + Send {}
-   |
+LL | impl LocalTraitOne for dyn fmt::Display + Send {}
+   |                        +++
 help: alternatively use a blanket implementation to implement `LocalTraitOne` for all types that also implement `fmt::Display + Send`
    |
 LL | impl<T: fmt::Display + Send> LocalTraitOne for T {}
@@ -78,9 +73,8 @@ LL | impl<E> GenericTrait<E> for LocalTraitOne {}
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl<E> GenericTrait<E> for LocalTraitOne {}
-LL + impl<E> GenericTrait<E> for dyn LocalTraitOne {}
-   |
+LL | impl<E> GenericTrait<E> for dyn LocalTraitOne {}
+   |                             +++
 help: alternatively use a blanket implementation to implement `GenericTrait<E>` for all types that also implement `LocalTraitOne`
    |
 LL | impl<E, T: LocalTraitOne> GenericTrait<E> for T {}
@@ -94,9 +88,8 @@ LL | impl<T, E> GenericTraitTwo<E> for GenericTrait<T> {}
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl<T, E> GenericTraitTwo<E> for GenericTrait<T> {}
-LL + impl<T, E> GenericTraitTwo<E> for dyn GenericTrait<T> {}
-   |
+LL | impl<T, E> GenericTraitTwo<E> for dyn GenericTrait<T> {}
+   |                                   +++
 help: alternatively use a blanket implementation to implement `GenericTraitTwo<E>` for all types that also implement `GenericTrait<T>`
    |
 LL | impl<T, E, U: GenericTrait<T>> GenericTraitTwo<E> for U {}
diff --git a/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait-edition-2021.stderr b/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait-edition-2021.stderr
index fc880d6b86a..87e71643620 100644
--- a/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait-edition-2021.stderr
+++ b/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait-edition-2021.stderr
@@ -39,9 +39,8 @@ LL | impl<'a, T> Struct<T> for Trait<'a, T> {}
    |
 help: add `dyn` keyword before this trait
    |
-LL - impl<'a, T> Struct<T> for Trait<'a, T> {}
-LL + impl<'a, T> Struct<T> for dyn Trait<'a, T> {}
-   |
+LL | impl<'a, T> Struct<T> for dyn Trait<'a, T> {}
+   |                           +++
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait.stderr b/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait.stderr
index f5143762da8..f716e6c17e2 100644
--- a/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait.stderr
+++ b/src/test/ui/suggestions/suggest-swapping-self-ty-and-trait.stderr
@@ -42,9 +42,8 @@ LL | impl<'a, T> Struct<T> for Trait<'a, T> {}
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - impl<'a, T> Struct<T> for Trait<'a, T> {}
-LL + impl<'a, T> Struct<T> for dyn Trait<'a, T> {}
-   |
+LL | impl<'a, T> Struct<T> for dyn Trait<'a, T> {}
+   |                           +++
 
 error: aborting due to 3 previous errors; 1 warning emitted
 
diff --git a/src/test/ui/traits/bound/not-on-bare-trait.stderr b/src/test/ui/traits/bound/not-on-bare-trait.stderr
index 8a92dd11872..1c52629daa4 100644
--- a/src/test/ui/traits/bound/not-on-bare-trait.stderr
+++ b/src/test/ui/traits/bound/not-on-bare-trait.stderr
@@ -9,9 +9,8 @@ LL | fn foo(_x: Foo + Send) {
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
 help: use `dyn`
    |
-LL - fn foo(_x: Foo + Send) {
-LL + fn foo(_x: dyn Foo + Send) {
-   |
+LL | fn foo(_x: dyn Foo + Send) {
+   |            +++
 
 error[E0277]: the size for values of type `(dyn Foo + Send + 'static)` cannot be known at compilation time
   --> $DIR/not-on-bare-trait.rs:7:8