fix: Use untrimmed line numbers for trimmed suggestions

Author: relaxcn

compiler/rustc_errors/src/diagnostic.rs

@@ -936,7 +936,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
         let parts = suggestion
             .into_iter()
-            .map(|(span, snippet)| SubstitutionPart { snippet, span })
+            .map(|(span, snippet)| SubstitutionPart { snippet, span, original_span: span })
             .collect::<Vec<_>>();
 
         assert!(!parts.is_empty());
@@ -1028,7 +1028,11 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         );
         self.push_suggestion(CodeSuggestion {
             substitutions: vec![Substitution {
-                parts: vec![SubstitutionPart { snippet: suggestion.to_string(), span: sp }],
+                parts: vec![SubstitutionPart {
+                    snippet: suggestion.to_string(),
+                    span: sp,
+                    original_span: sp,
+                }],
             }],
             msg: self.subdiagnostic_message_to_diagnostic_message(msg),
             style,
@@ -1093,7 +1097,9 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
                     !(sp.is_empty() && snippet.is_empty()),
                     "Span `{sp:?}` must not be empty and have no suggestion"
                 );
-                Substitution { parts: vec![SubstitutionPart { snippet, span: sp }] }
+                Substitution {
+                    parts: vec![SubstitutionPart { snippet, span: sp, original_span: sp }],
+                }
             })
             .collect();
         self.push_suggestion(CodeSuggestion {
@@ -1120,7 +1126,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
             .map(|sugg| {
                 let mut parts = sugg
                     .into_iter()
-                    .map(|(span, snippet)| SubstitutionPart { snippet, span })
+                    .map(|(span, snippet)| SubstitutionPart { snippet, span, original_span: span })
                     .collect::<Vec<_>>();
 
                 parts.sort_unstable_by_key(|part| part.span);

compiler/rustc_errors/src/emitter.rs

@@ -2154,11 +2154,11 @@ impl HumanEmitter {
 
             assert!(!file_lines.lines.is_empty() || parts[0].span.is_dummy());
 
-            let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
+            let line_start = sm.lookup_char_pos(parts[0].original_span.lo()).line;
             let mut lines = complete.lines();
             if lines.clone().next().is_none() {
                 // Account for a suggestion to completely remove a line(s) with whitespace (#94192).
-                let line_end = sm.lookup_char_pos(parts[0].span.hi()).line;
+                let line_end = sm.lookup_char_pos(parts[0].original_span.hi()).line;
                 for line in line_start..=line_end {
                     self.draw_line_num(
                         &mut buffer,

compiler/rustc_errors/src/lib.rs

@@ -222,6 +222,7 @@ pub struct Substitution {
 pub struct SubstitutionPart {
     pub span: Span,
     pub snippet: String,
+    pub original_span: Span,
 }
 
 /// Used to translate between `Span`s and byte positions within a single output line in highlighted

tests/ui/error-emitter/trimmed_multiline_suggestion.rs

@@ -0,0 +1,14 @@
+//@ compile-flags: -Z ui-testing=no
+fn function_with_lots_of_arguments(a: i32, b: char, c: i32, d: i32, e: i32, f: i32) {}
+
+fn main() {
+    let variable_name = 42;
+    function_with_lots_of_arguments(
+        variable_name,
+        variable_name,
+        variable_name,
+        variable_name,
+        variable_name,
+    );
+    //~^^^^^^^ ERROR this function takes 6 arguments but 5 arguments were supplied [E0061]
+}

tests/ui/error-emitter/trimmed_multiline_suggestion.stderr

@@ -0,0 +1,25 @@
+error[E0061]: this function takes 6 arguments but 5 arguments were supplied
+ --> $DIR/trimmed_multiline_suggestion.rs:6:5
+  |
+6 |     function_with_lots_of_arguments(
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+7 |         variable_name,
+8 |         variable_name,
+  |         ------------- argument #2 of type `char` is missing
+  |
+note: function defined here
+ --> $DIR/trimmed_multiline_suggestion.rs:2:4
+  |
+2 | fn function_with_lots_of_arguments(a: i32, b: char, c: i32, d: i32, e: i32, f: i32) {}
+  |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^         -------
+help: provide the argument
+  |
+6 |     function_with_lots_of_arguments(
+7 |         variable_name,
+8 ~         /* char */,
+9 ~         variable_name,
+  |
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0061`.