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expand: Do not count metavar declarations on RHS of macro_rules

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They are 0 by definition there.
This commit is contained in:
Vadim Petrochenkov 2022-03-31 18:56:40 +03:00
parent 03314912f1
commit 9ab4f732cb
2 changed files with 10 additions and 15 deletions
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18
compiler/rustc_expand/src/mbe/macro_parser.rs
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@ -263,18 +263,12 @@ crate type NamedParseResult = ParseResult<FxHashMap<MacroRulesNormalizedIdent, N
pub(super) fn count_metavar_decls(matcher: &[TokenTree]) -> usize {
matcher
.iter()
.map(|tt| {
match tt {
TokenTree::Delimited(_, delim) => count_metavar_decls(delim.inner_tts()),
TokenTree::MetaVar(..) => 0,
TokenTree::MetaVarDecl(..) => 1,
// RHS meta-variable expressions eventually end-up here. `0` is returned to inform
// that no meta-variable was found, because "meta-variables" != "meta-variable
// expressions".
TokenTree::MetaVarExpr(..) => 0,
TokenTree::Sequence(_, seq) => seq.num_captures,
TokenTree::Token(..) => 0,
}
.map(|tt| match tt {
TokenTree::MetaVarDecl(..) => 1,
TokenTree::Sequence(_, seq) => seq.num_captures,
TokenTree::Delimited(_, delim) => count_metavar_decls(delim.inner_tts()),
TokenTree::Token(..) => 0,
TokenTree::MetaVar(..) | TokenTree::MetaVarExpr(..) => unreachable!(),
})
.sum()
}