From eb8aa9759dc99b604145f94e5296b7add60e0a48 Mon Sep 17 00:00:00 2001 From: yukang Date: Wed, 19 Oct 2022 11:46:26 +0800 Subject: [PATCH] Add testcase for next_point, fix more trivial issues in find_width_of_character_at_span --- compiler/rustc_span/src/source_map.rs | 19 ++++++--- compiler/rustc_span/src/source_map/tests.rs | 45 +++++++++++++++++++++ src/tools/clippy/clippy_utils/src/sugg.rs | 3 +- 3 files changed, 59 insertions(+), 8 deletions(-) diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs index d3c2550aa2afb..506ce6955d399 100644 --- a/compiler/rustc_span/src/source_map.rs +++ b/compiler/rustc_span/src/source_map.rs @@ -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(); diff --git a/compiler/rustc_span/src/source_map/tests.rs b/compiler/rustc_span/src/source_map/tests.rs index 3058ec45a6468..1fd81018fa05c 100644 --- a/compiler/rustc_span/src/source_map/tests.rs +++ b/compiler/rustc_span/src/source_map/tests.rs @@ -479,3 +479,48 @@ fn path_prefix_remapping_expand_to_absolute() { RealFileName::Remapped { local_path: None, virtual_name: path("XYZ/src/main.rs") } ); } + +#[test] +fn test_next_point() { + let sm = SourceMap::new(FilePathMapping::empty()); + sm.new_source_file(PathBuf::from("example.rs").into(), "a…b".to_string()); + + // Dummy spans don't advance. + let span = DUMMY_SP; + let span = sm.next_point(span); + assert_eq!(span.lo().0, 0); + assert_eq!(span.hi().0, 0); + + // Span advance respect multi-byte character + let span = Span::with_root_ctxt(BytePos(0), BytePos(1)); + assert_eq!(sm.span_to_snippet(span), Ok("a".to_string())); + let span = sm.next_point(span); + assert_eq!(sm.span_to_snippet(span), Ok("…".to_string())); + assert_eq!(span.lo().0, 1); + assert_eq!(span.hi().0, 4); + + // An empty span pointing just before a multi-byte character should + // advance to contain the multi-byte character. + let span = Span::with_root_ctxt(BytePos(1), BytePos(1)); + let span = sm.next_point(span); + assert_eq!(span.lo().0, 1); + assert_eq!(span.hi().0, 4); + + let span = Span::with_root_ctxt(BytePos(1), BytePos(4)); + let span = sm.next_point(span); + assert_eq!(span.lo().0, 4); + assert_eq!(span.hi().0, 5); + + // A non-empty span at the last byte should advance to create an empty + // span pointing at the end of the file. + let span = Span::with_root_ctxt(BytePos(4), BytePos(5)); + let span = sm.next_point(span); + assert_eq!(span.lo().0, 5); + assert_eq!(span.hi().0, 5); + + // Empty span pointing just past the last byte. + let span = Span::with_root_ctxt(BytePos(5), BytePos(5)); + let span = sm.next_point(span); + assert_eq!(span.lo().0, 5); + assert_eq!(span.hi().0, 5); +} diff --git a/src/tools/clippy/clippy_utils/src/sugg.rs b/src/tools/clippy/clippy_utils/src/sugg.rs index 3c5dd92b9cd6d..3347342e412b6 100644 --- a/src/tools/clippy/clippy_utils/src/sugg.rs +++ b/src/tools/clippy/clippy_utils/src/sugg.rs @@ -769,8 +769,7 @@ impl DiagnosticExt for rustc_errors::Diagnostic { fn suggest_remove_item(&mut self, cx: &T, item: Span, msg: &str, applicability: Applicability) { let mut remove_span = item; - let hi = cx.sess().source_map().next_point(remove_span).hi(); - let fmpos = cx.sess().source_map().lookup_byte_offset(hi); + let fmpos = cx.sess().source_map().lookup_byte_offset(remove_span.hi()); if let Some(ref src) = fmpos.sf.src { let non_whitespace_offset = src[fmpos.pos.to_usize()..].find(|c| c != ' ' && c != '\t' && c != '\n');