Use shorter span for existing ' -> " structured suggestion

Author: estebank

compiler/rustc_infer/src/errors/mod.rs

@@ -1339,15 +1339,12 @@ pub enum TypeErrorAdditionalDiags {
         span: Span,
         code: String,
     },
-    #[suggestion(
-        infer_meant_str_literal,
-        code = "\"{code}\"",
-        applicability = "machine-applicable"
-    )]
+    #[multipart_suggestion(infer_meant_str_literal, applicability = "machine-applicable")]
     MeantStrLiteral {
-        #[primary_span]
-        span: Span,
-        code: String,
+        #[suggestion_part(code = "\"")]
+        start: Span,
+        #[suggestion_part(code = "\"")]
+        end: Span,
     },
     #[suggestion(
         infer_consider_specifying_length,

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2078,16 +2078,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 // If a string was expected and the found expression is a character literal,
                 // perhaps the user meant to write `"s"` to specify a string literal.
                 (ty::Ref(_, r, _), ty::Char) if r.is_str() => {
-                    if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span) {
-                        if let Some(code) =
-                            code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
-                        {
-                            suggestions.push(TypeErrorAdditionalDiags::MeantStrLiteral {
-                                span,
-                                code: escape_literal(code),
-                            })
-                        }
-                    }
+                    suggestions.push(TypeErrorAdditionalDiags::MeantStrLiteral {
+                        start: span.with_hi(span.lo() + BytePos(1)),
+                        end: span.with_lo(span.hi() - BytePos(1)),
+                    })
                 }
                 // For code `if Some(..) = expr `, the type mismatch may be expected `bool` but found `()`,
                 // we try to suggest to add the missing `let` for `if let Some(..) = expr`

compiler/rustc_parse/src/errors.rs

@@ -2216,12 +2216,21 @@ pub enum MoreThanOneCharSugg {
         ch: String,
     },
     #[suggestion(parse_use_double_quotes, code = "{sugg}", applicability = "machine-applicable")]
-    Quotes {
+    QuotesFull {
         #[primary_span]
         span: Span,
         is_byte: bool,
         sugg: String,
     },
+    #[multipart_suggestion(parse_use_double_quotes, applicability = "machine-applicable")]
+    Quotes {
+        #[suggestion_part(code = "{prefix}\"")]
+        start: Span,
+        #[suggestion_part(code = "\"")]
+        end: Span,
+        is_byte: bool,
+        prefix: &'static str,
+    },
 }
 
 #[derive(Subdiagnostic)]

compiler/rustc_parse/src/lexer/unescape_error_reporting.rs

@@ -95,11 +95,21 @@ pub(crate) fn emit_unescape_error(
                     }
                     escaped.push(c);
                 }
-                let sugg = format!("{prefix}\"{escaped}\"");
-                MoreThanOneCharSugg::Quotes {
-                    span: full_lit_span,
-                    is_byte: mode == Mode::Byte,
-                    sugg,
+                if escaped.len() != lit.len() {
+                    let sugg = format!("{prefix}\"{escaped}\"");
+                    MoreThanOneCharSugg::QuotesFull {
+                        span: full_lit_span,
+                        is_byte: mode == Mode::Byte,
+                        sugg,
+                    }
+                } else {
+                    MoreThanOneCharSugg::Quotes {
+                        start: full_lit_span
+                            .with_hi(full_lit_span.lo() + BytePos((prefix.len() + 1) as u32)),
+                        end: full_lit_span.with_lo(full_lit_span.hi() - BytePos(1)),
+                        is_byte: mode == Mode::Byte,
+                        prefix,
+                    }
                 }
             });
             dcx.emit_err(UnescapeError::MoreThanOneChar {

tests/ui/inference/str-as-char.stderr

@@ -18,7 +18,7 @@ LL |     let _: &str = '\"\"\"';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let _: &str = "\"\"\"";
-   |                   ~~~~~~~~
+   |                   ~      ~
 
 error: character literal may only contain one codepoint
   --> $DIR/str-as-char.rs:10:19
@@ -42,7 +42,7 @@ LL |     let _: &str = 'a';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let _: &str = "a";
-   |                   ~~~
+   |                   ~ ~
 
 error: aborting due to 4 previous errors
 

tests/ui/issues/issue-23589.stderr

@@ -18,7 +18,7 @@ LL |     let v: Vec(&str) = vec!['1', '2'];
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let v: Vec(&str) = vec!["1", '2'];
-   |                             ~~~
+   |                             ~ ~
 
 error: aborting due to 2 previous errors
 

tests/ui/lexer/lex-bad-char-literals-2.stderr

@@ -7,7 +7,7 @@ LL |     'nope'
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     "nope"
-   |     ~~~~~~
+   |     ~    ~
 
 error: aborting due to 1 previous error
 

tests/ui/lexer/lex-bad-char-literals-3.stderr

@@ -7,7 +7,7 @@ LL | static c: char = '●●';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL | static c: char = "●●";
-   |                  ~~~~
+   |                  ~  ~
 
 error: character literal may only contain one codepoint
   --> $DIR/lex-bad-char-literals-3.rs:5:20
@@ -18,7 +18,7 @@ LL |     let ch: &str = '●●';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let ch: &str = "●●";
-   |                    ~~~~
+   |                    ~  ~
 
 error: aborting due to 2 previous errors
 

tests/ui/lexer/lex-bad-char-literals-5.stderr

@@ -7,7 +7,7 @@ LL | static c: char = '\x10\x10';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL | static c: char = "\x10\x10";
-   |                  ~~~~~~~~~~
+   |                  ~        ~
 
 error: character literal may only contain one codepoint
   --> $DIR/lex-bad-char-literals-5.rs:5:20
@@ -18,7 +18,7 @@ LL |     let ch: &str = '\x10\x10';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let ch: &str = "\x10\x10";
-   |                    ~~~~~~~~~~
+   |                    ~        ~
 
 error: aborting due to 2 previous errors
 

tests/ui/lexer/lex-bad-char-literals-6.stderr

@@ -7,7 +7,7 @@ LL |     let x: &str = 'ab';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let x: &str = "ab";
-   |                   ~~~~
+   |                   ~  ~
 
 error: character literal may only contain one codepoint
   --> $DIR/lex-bad-char-literals-6.rs:4:19
@@ -18,7 +18,7 @@ LL |     let y: char = 'cd';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let y: char = "cd";
-   |                   ~~~~
+   |                   ~  ~
 
 error: character literal may only contain one codepoint
   --> $DIR/lex-bad-char-literals-6.rs:6:13
@@ -29,7 +29,7 @@ LL |     let z = 'ef';
 help: if you meant to write a `str` literal, use double quotes
    |
 LL |     let z = "ef";
-   |             ~~~~
+   |             ~  ~
 
 error[E0308]: mismatched types
   --> $DIR/lex-bad-char-literals-6.rs:13:20