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Add testcase for next_point, fix more trivial issues in find_width_of_character_at_span

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yukang
2022-10-19 11:46:26 +08:00
parent 0af255a5aa
commit eb8aa9759d
3 changed files with 59 additions and 8 deletions
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19
compiler/rustc_span/src/source_map.rs
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@@ -853,6 +853,10 @@ impl SourceMap {
}
/// Returns a new span representing the next character after the end-point of this span.
/// Special cases:
/// - if span is a dummy one, returns the same span
/// - if next_point reached the end of source, return span with lo = hi
/// - respect multi-byte characters
pub fn next_point(&self, sp: Span) -> Span {
if sp.is_dummy() {
return sp;
@@ -860,9 +864,11 @@ impl SourceMap {
let start_of_next_point = sp.hi().0;
let width = self.find_width_of_character_at_span(sp, true);
debug_assert!(width > 0);
// 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
if width == 0 {
return Span::new(sp.hi(), sp.hi(), sp.ctxt(), None);
}
// If the width is 1, then the next span should only contain the next char besides current ending.
// However, in the case of a multibyte character, where the width != 1, the next span should
// span multiple bytes to include the whole character.
let end_of_next_point =
start_of_next_point.checked_add(width).unwrap_or(start_of_next_point);
@@ -875,7 +881,8 @@ impl SourceMap {
/// depending on the `forwards` parameter.
fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 {
let sp = sp.data();
if sp.lo == sp.hi {
if sp.lo == sp.hi && !forwards {
debug!("find_width_of_character_at_span: early return empty span");
return 1;
}
@@ -909,9 +916,9 @@ impl SourceMap {
let source_len = (local_begin.sf.end_pos - local_begin.sf.start_pos).to_usize();
debug!("find_width_of_character_at_span: source_len=`{:?}`", source_len);
// Ensure indexes are also not malformed.
if start_index > end_index || end_index > source_len {
if start_index > end_index || end_index > source_len - 1 {
debug!("find_width_of_character_at_span: source indexes are malformed");
return 1;
return 0;
}
let src = local_begin.sf.external_src.borrow();