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| author | Nicholas Nethercote <n.nethercote@gmail.com> | 2022-04-08 14:25:37 +1000 |
|---|---|---|
| committer | Nicholas Nethercote <n.nethercote@gmail.com> | 2022-04-11 09:38:40 +1000 |
| commit | edd7f2cdab424ff8ed64a84f784a5c1273bcb138 (patch) | |
| tree | daa9ad9b04681959149c9bddac2752df2b93dce2 /compiler/rustc_expand/src/mbe/macro_parser.rs | |
| parent | 4ba609601f1a99ddf3cf0cf70f57c4a045f0f23f (diff) | |
| download | rust-edd7f2cdab424ff8ed64a84f784a5c1273bcb138.tar.gz rust-edd7f2cdab424ff8ed64a84f784a5c1273bcb138.zip | |
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Diffstat (limited to 'compiler/rustc_expand/src/mbe/macro_parser.rs')
| -rw-r--r-- | compiler/rustc_expand/src/mbe/macro_parser.rs | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs index d26f80e82fc..b5f56d7d6dc 100644 --- a/compiler/rustc_expand/src/mbe/macro_parser.rs +++ b/compiler/rustc_expand/src/mbe/macro_parser.rs @@ -211,6 +211,10 @@ struct MatcherPos { /// with one element per metavar decl in the matcher. Each element records token trees matched /// against the relevant metavar by the black box parser. An element will be a `MatchedSeq` if /// the corresponding metavar decl is within a sequence. + /// + /// It is critical to performance that this is an `Lrc`, because it gets cloned frequently when + /// processing sequences. Mostly for sequence-ending possibilities that must be tried but end + /// up failing. matches: Lrc<Vec<NamedMatch>>, } |