From 0bd96671f0312fdc1eb07885835e58d258f1f927 Mon Sep 17 00:00:00 2001 From: David Wood Date: Sat, 27 Jan 2018 13:30:34 +0000 Subject: [PATCH] Fixed infinite loop issues and added some improved logging. --- src/libsyntax/codemap.rs | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs index 8c1bdab28a9d5..a6a7f9e20b3a9 100644 --- a/src/libsyntax/codemap.rs +++ b/src/libsyntax/codemap.rs @@ -638,25 +638,33 @@ impl CodeMap { fn find_width_of_character_at_span(&self, sp: Span, forwards: bool) -> u32 { // Disregard malformed spans and assume a one-byte wide character. if sp.lo() >= sp.hi() { + debug!("find_width_of_character_at_span: early return malformed span"); return 1; } let local_begin = self.lookup_byte_offset(sp.lo()); let local_end = self.lookup_byte_offset(sp.hi()); + debug!("find_width_of_character_at_span: local_begin=`{:?}`, local_end=`{:?}`", + local_begin, local_end); let start_index = local_begin.pos.to_usize(); let end_index = local_end.pos.to_usize(); + debug!("find_width_of_character_at_span: start_index=`{:?}`, end_index=`{:?}`", + start_index, end_index); // Disregard indexes that are at the start or end of their spans, they can't fit bigger // characters. if (!forwards && end_index == usize::min_value()) || (forwards && start_index == usize::max_value()) { + debug!("find_width_of_character_at_span: start or end of span, cannot be multibyte"); return 1; } let source_len = (local_begin.fm.end_pos - local_begin.fm.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 { + debug!("find_width_of_character_at_span: source indexes are malformed"); return 1; } @@ -671,16 +679,22 @@ impl CodeMap { } else { return 1; }; - debug!("DTW start {:?} end {:?}", start_index, end_index); - debug!("DTW snippet {:?}", snippet); + debug!("find_width_of_character_at_span: snippet=`{:?}`", snippet); + + let file_start_pos = local_begin.fm.start_pos.to_usize(); + let file_end_pos = local_begin.fm.end_pos.to_usize(); + debug!("find_width_of_character_at_span: file_start_pos=`{:?}` file_end_pos=`{:?}`", + file_start_pos, file_end_pos); let mut target = if forwards { end_index + 1 } else { end_index - 1 }; - debug!("DTW initial target {:?}", target); - while !snippet.is_char_boundary(target - start_index) { + debug!("find_width_of_character_at_span: initial target=`{:?}`", target); + + while !snippet.is_char_boundary(target - start_index) + && target >= file_start_pos && target <= file_end_pos { target = if forwards { target + 1 } else { target - 1 }; - debug!("DTW update target {:?}", target); + debug!("find_width_of_character_at_span: target=`{:?}`", target); } - debug!("DTW final target {:?}", target); + debug!("find_width_of_character_at_span: final target=`{:?}`", target); if forwards { (target - end_index) as u32