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Fix macro_metavar_expr_concat behavior with nested repetitions

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This commit is contained in:
delta17920 2025-12-15 15:28:57 +00:00
parent ed0006a7ba
commit 3566b6775c
6 changed files with 63 additions and 34 deletions
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29
compiler/rustc_expand/src/mbe/transcribe.rs
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@ -558,25 +558,20 @@ fn metavar_expr_concat<'tx>(
MetaVarExprConcatElem::Ident(elem) => elem.name,
MetaVarExprConcatElem::Literal(elem) => *elem,
MetaVarExprConcatElem::Var(ident) => {
match matched_from_ident(dcx, *ident, tscx.interp)? {
NamedMatch::MatchedSeq(named_matches) => {
let Some((curr_idx, _)) = tscx.repeats.last() else {
return Err(dcx.struct_span_err(dspan.entire(), "invalid syntax"));
};
match &named_matches[*curr_idx] {
// FIXME(c410-f3r) Nested repetitions are unimplemented
MatchedSeq(_) => {
return Err(dcx.struct_span_err(
ident.span,
"nested repetitions with `${concat(...)}` metavariable expressions are not yet supported",
));
}
MatchedSingle(pnr) => extract_symbol_from_pnr(dcx, pnr, ident.span)?,
}
}
NamedMatch::MatchedSingle(pnr) => {
let key = MacroRulesNormalizedIdent::new(*ident);
match lookup_cur_matched(key, tscx.interp, &tscx.repeats) {
Some(NamedMatch::MatchedSingle(pnr)) => {
extract_symbol_from_pnr(dcx, pnr, ident.span)?
}
Some(NamedMatch::MatchedSeq(..)) => {
return Err(dcx.struct_span_err(
ident.span,
"`${concat(...)}` variable is still repeating at this depth",
));
}
None => {
return Err(dcx.create_err(MveUnrecognizedVar { span: ident.span, key }));
}
}
}
};