Auto merge of #68423 - Centril:rollup-bdjykrv, r=Centril

[rust.git] / src / librustc_span / source_map.rs

diff --git a/src/librustc_span/source_map.rs b/src/librustc_span/source_map.rs
index 0b9b9fe7887f2a29fe86090381877061204624cd..9c7c0f0c8b0eca79346dd05357cf2fede430baa2 100644 (file)
--- a/src/librustc_span/source_map.rs
+++ b/src/librustc_span/source_map.rs
@@ -473,20 +473,23 @@ pub fn is_multiline(&self, sp: Span) -> bool {
         lo.line != hi.line
     }
 
-    pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
-        debug!("span_to_lines(sp={:?})", sp);
-
+    pub fn is_valid_span(&self, sp: Span) -> Result<(Loc, Loc), SpanLinesError> {
         let lo = self.lookup_char_pos(sp.lo());
         debug!("span_to_lines: lo={:?}", lo);
         let hi = self.lookup_char_pos(sp.hi());
         debug!("span_to_lines: hi={:?}", hi);
-
         if lo.file.start_pos != hi.file.start_pos {
             return Err(SpanLinesError::DistinctSources(DistinctSources {
                 begin: (lo.file.name.clone(), lo.file.start_pos),
                 end: (hi.file.name.clone(), hi.file.start_pos),
             }));
         }
+        Ok((lo, hi))
+    }
+
+    pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
+        debug!("span_to_lines(sp={:?})", sp);
+        let (lo, hi) = self.is_valid_span(sp)?;
         assert!(hi.line >= lo.line);
 
         let mut lines = Vec::with_capacity(hi.line - lo.line + 1);
@@ -499,14 +502,15 @@ pub fn span_to_lines(&self, sp: Span) -> FileLinesResult {
         // and to the end of the line. Be careful because the line
         // numbers in Loc are 1-based, so we subtract 1 to get 0-based
         // lines.
-        for line_index in lo.line - 1..hi.line - 1 {
+        let hi_line = hi.line.saturating_sub(1);
+        for line_index in lo.line.saturating_sub(1)..hi_line {
             let line_len = lo.file.get_line(line_index).map(|s| s.chars().count()).unwrap_or(0);
             lines.push(LineInfo { line_index, start_col, end_col: CharPos::from_usize(line_len) });
             start_col = CharPos::from_usize(0);
         }
 
         // For the last line, it extends from `start_col` to `hi.col`:
-        lines.push(LineInfo { line_index: hi.line - 1, start_col, end_col: hi.col });
+        lines.push(LineInfo { line_index: hi_line, start_col, end_col: hi.col });
 
         Ok(FileLines { file: lo.file, lines })
     }
@@ -709,7 +713,7 @@ pub fn end_point(&self, sp: Span) -> Span {
     pub fn next_point(&self, sp: Span) -> Span {
         let start_of_next_point = sp.hi().0;
 
-        let width = self.find_width_of_character_at_span(sp, true);
+        let width = self.find_width_of_character_at_span(sp.shrink_to_hi(), true);
         // If the width is 1, then the next span should point to the same `lo` and `hi`. However,
         // in the case of a multibyte character, where the width != 1, the next span should
         // span multiple bytes to include the whole character.