bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Avoid unbounded O(n^2) when parsing nested type args

Browse source 
When encountering code like `f::<f::<f::<f::<f::<f::<f::<f::<...` with
unmatched closing angle brackets, add a linear check that avoids the
exponential behavior of the parse recovery mechanism.

Fix #117080.
This commit is contained in:
Esteban Küber 2023-10-24 22:22:52 +00:00
parent 855444ec54
commit 2dec1bc685
4 changed files with 55 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

6
compiler/rustc_parse/src/parser/mod.rs
View file

@ -159,8 +159,9 @@ pub struct Parser<'a> {
/// appropriately.
///
/// See the comments in the `parse_path_segment` function for more details.
unmatched_angle_bracket_count: u32,
max_angle_bracket_count: u32,
unmatched_angle_bracket_count: u16,
max_angle_bracket_count: u16,
angle_bracket_nesting: u16,
last_unexpected_token_span: Option<Span>,
/// If present, this `Parser` is not parsing Rust code but rather a macro call.
@ -394,6 +395,7 @@ impl<'a> Parser<'a> {
break_last_token: false,
unmatched_angle_bracket_count: 0,
max_angle_bracket_count: 0,
angle_bracket_nesting: 0,
last_unexpected_token_span: None,
subparser_name,
capture_state: CaptureState {