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Remember the span of the Kleene operator in macros
This is needed for having complete error messages where reporting macro variable errors. Here is what they would look like: error: meta-variable repeats with different kleene operator --> $DIR/issue-61053-different-kleene.rs:3:57 | LL | ( $( $i:ident = $($j:ident),+ );* ) => { $( $( $i = $j; )* )* }; | - expected repetition ^^ - conflicting repetition
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4 files changed

+33
-21
lines changed

4 files changed

+33
-21
lines changed

‎src/libsyntax/ext/tt/macro_parser.rs‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -557,8 +557,8 @@ fn inner_parse_loop<'root, 'tt>(
557557
// implicitly disallowing OneOrMore from having 0 matches here. Thus, that will
558558
// result in a "no rules expected token" error by virtue of this matcher not
559559
// working.
560-
if seq.op == quoted::KleeneOp::ZeroOrMore
561-
|| seq.op == quoted::KleeneOp::ZeroOrOne
560+
if seq.kleene.op == quoted::KleeneOp::ZeroOrMore
561+
|| seq.kleene.op == quoted::KleeneOp::ZeroOrOne
562562
{
563563
let mut new_item = item.clone();
564564
new_item.match_cur += seq.num_captures;
@@ -573,7 +573,7 @@ fn inner_parse_loop<'root, 'tt>(
573573
cur_items.push(MatcherPosHandle::Box(Box::new(MatcherPos {
574574
stack: smallvec![],
575575
sep: seq.separator.clone(),
576-
seq_op: Some(seq.op),
576+
seq_op: Some(seq.kleene.op),
577577
idx: 0,
578578
matches,
579579
match_lo: item.match_cur,

‎src/libsyntax/ext/tt/macro_rules.rs‎

Lines changed: 8 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -273,7 +273,7 @@ pub fn compile(
273273
if body.legacy { token::Semi } else { token::Comma },
274274
def.span,
275275
)),
276-
op: quoted::KleeneOp::OneOrMore,
276+
kleene: quoted::KleeneToken::new(quoted::KleeneOp::OneOrMore, def.span),
277277
num_captures: 2,
278278
}),
279279
),
@@ -283,7 +283,7 @@ pub fn compile(
283283
Lrc::new(quoted::SequenceRepetition {
284284
tts: vec![quoted::TokenTree::token(token::Semi, def.span)],
285285
separator: None,
286-
op: quoted::KleeneOp::ZeroOrMore,
286+
kleene: quoted::KleeneToken::new(quoted::KleeneOp::ZeroOrMore, def.span),
287287
num_captures: 0,
288288
}),
289289
),
@@ -477,8 +477,8 @@ fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[quoted::TokenTree]) -> bool {
477477
&& seq.tts.iter().all(|seq_tt| match *seq_tt {
478478
TokenTree::MetaVarDecl(_, _, id) => id.name == sym::vis,
479479
TokenTree::Sequence(_, ref sub_seq) => {
480-
sub_seq.op == quoted::KleeneOp::ZeroOrMore
481-
|| sub_seq.op == quoted::KleeneOp::ZeroOrOne
480+
sub_seq.kleene.op == quoted::KleeneOp::ZeroOrMore
481+
|| sub_seq.kleene.op == quoted::KleeneOp::ZeroOrOne
482482
}
483483
_ => false,
484484
})
@@ -628,8 +628,8 @@ impl FirstSets {
628628

629629
// Reverse scan: Sequence comes before `first`.
630630
if subfirst.maybe_empty
631-
|| seq_rep.op == quoted::KleeneOp::ZeroOrMore
632-
|| seq_rep.op == quoted::KleeneOp::ZeroOrOne
631+
|| seq_rep.kleene.op == quoted::KleeneOp::ZeroOrMore
632+
|| seq_rep.kleene.op == quoted::KleeneOp::ZeroOrOne
633633
{
634634
// If sequence is potentially empty, then
635635
// union them (preserving first emptiness).
@@ -677,8 +677,8 @@ impl FirstSets {
677677
assert!(first.maybe_empty);
678678
first.add_all(subfirst);
679679
if subfirst.maybe_empty
680-
|| seq_rep.op == quoted::KleeneOp::ZeroOrMore
681-
|| seq_rep.op == quoted::KleeneOp::ZeroOrOne
680+
|| seq_rep.kleene.op == quoted::KleeneOp::ZeroOrMore
681+
|| seq_rep.kleene.op == quoted::KleeneOp::ZeroOrOne
682682
{
683683
// continue scanning for more first
684684
// tokens, but also make sure we

‎src/libsyntax/ext/tt/quoted.rs‎

Lines changed: 21 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -50,11 +50,23 @@ pub struct SequenceRepetition {
5050
/// The optional separator
5151
pub separator: Option<Token>,
5252
/// Whether the sequence can be repeated zero (*), or one or more times (+)
53-
pub op: KleeneOp,
53+
pub kleene: KleeneToken,
5454
/// The number of `Match`s that appear in the sequence (and subsequences)
5555
pub num_captures: usize,
5656
}
5757

58+
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
59+
pub struct KleeneToken {
60+
pub span: Span,
61+
pub op: KleeneOp,
62+
}
63+
64+
impl KleeneToken {
65+
pub fn new(op: KleeneOp, span: Span) -> KleeneToken {
66+
KleeneToken { span, op }
67+
}
68+
}
69+
5870
/// A Kleene-style [repetition operator](http://en.wikipedia.org/wiki/Kleene_star)
5971
/// for token sequences.
6072
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
@@ -273,15 +285,15 @@ fn parse_tree(
273285
macro_node_id,
274286
);
275287
// Get the Kleene operator and optional separator
276-
let (separator, op) = parse_sep_and_kleene_op(trees, span.entire(), sess);
288+
let (separator, kleene) = parse_sep_and_kleene_op(trees, span.entire(), sess);
277289
// Count the number of captured "names" (i.e., named metavars)
278290
let name_captures = macro_parser::count_names(&sequence);
279291
TokenTree::Sequence(
280292
span,
281293
Lrc::new(SequenceRepetition {
282294
tts: sequence,
283295
separator,
284-
op,
296+
kleene,
285297
num_captures: name_captures,
286298
}),
287299
)
@@ -379,28 +391,28 @@ fn parse_sep_and_kleene_op(
379391
input: &mut Peekable<impl Iterator<Item = tokenstream::TokenTree>>,
380392
span: Span,
381393
sess: &ParseSess,
382-
) -> (Option<Token>, KleeneOp) {
394+
) -> (Option<Token>, KleeneToken) {
383395
// We basically look at two token trees here, denoted as #1 and #2 below
384396
let span = match parse_kleene_op(input, span) {
385397
// #1 is a `?`, `+`, or `*` KleeneOp
386-
Ok(Ok((op, _))) => return (None, op),
398+
Ok(Ok((op, span))) => return (None, KleeneToken::new(op, span)),
387399

388400
// #1 is a separator followed by #2, a KleeneOp
389401
Ok(Err(token)) => match parse_kleene_op(input, token.span) {
390402
// #2 is the `?` Kleene op, which does not take a separator (error)
391-
Ok(Ok((KleeneOp::ZeroOrOne, _))) => {
403+
Ok(Ok((KleeneOp::ZeroOrOne, span))) => {
392404
// Error!
393405
sess.span_diagnostic.span_err(
394406
token.span,
395407
"the `?` macro repetition operator does not take a separator",
396408
);
397409

398410
// Return a dummy
399-
return (None, KleeneOp::ZeroOrMore);
411+
return (None, KleeneToken::new(KleeneOp::ZeroOrMore, span));
400412
}
401413

402414
// #2 is a KleeneOp :D
403-
Ok(Ok((op, _))) => return (Some(token), op),
415+
Ok(Ok((op, span))) => return (Some(token), KleeneToken::new(op, span)),
404416

405417
// #2 is a random token or not a token at all :(
406418
Ok(Err(Token { span, .. })) | Err(span) => span,
@@ -414,5 +426,5 @@ fn parse_sep_and_kleene_op(
414426
sess.span_diagnostic.span_err(span, "expected one of: `*`, `+`, or `?`");
415427

416428
// Return a dummy
417-
(None, KleeneOp::ZeroOrMore)
429+
(None, KleeneToken::new(KleeneOp::ZeroOrMore, span))
418430
}

‎src/libsyntax/ext/tt/transcribe.rs‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -183,7 +183,7 @@ pub fn transcribe(
183183

184184
// Is the repetition empty?
185185
if len == 0 {
186-
if seq.op == quoted::KleeneOp::OneOrMore {
186+
if seq.kleene.op == quoted::KleeneOp::OneOrMore {
187187
// FIXME: this really ought to be caught at macro definition
188188
// time... It happens when the Kleene operator in the matcher and
189189
// the body for the same meta-variable do not match.

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