mirror of https://github.com/rust-lang/rust.git
Rollup merge of #51417 - pietroalbini:revert-49719, r=nikomatsakis
Revert #49719 This also needs to be backported into beta. Fixes #51416. r? @nikomatsakis
This commit is contained in:
kennytm
GitHub
commit
e46ef1bb86
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@ -386,25 +386,71 @@ where
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{
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// We basically look at two token trees here, denoted as #1 and #2 below
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let span = match parse_kleene_op(input, span) {
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// #1 is any KleeneOp (`?`)
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Ok(Ok(op)) if op == KleeneOp::ZeroOrOne => {
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if !features.macro_at_most_once_rep
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&& !attr::contains_name(attrs, "allow_internal_unstable")
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{
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let explain = feature_gate::EXPLAIN_MACRO_AT_MOST_ONCE_REP;
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emit_feature_err(
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sess,
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"macro_at_most_once_rep",
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span,
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GateIssue::Language,
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explain,
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);
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}
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return (None, op);
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}
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// #1 is a `+` or `*` KleeneOp
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//
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// `?` is ambiguous: it could be a separator or a Kleene::ZeroOrOne, so we need to look
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// ahead one more token to be sure.
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Ok(Ok(op)) if op != KleeneOp::ZeroOrOne => return (None, op),
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// #1 is any KleeneOp (`+`, `*`)
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Ok(Ok(op)) => return (None, op),
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// #1 is `?` token, but it could be a Kleene::ZeroOrOne without a separator or it could
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// be a `?` separator followed by any Kleene operator. We need to look ahead 1 token to
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// find out which.
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Ok(Ok(op)) => {
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assert_eq!(op, KleeneOp::ZeroOrOne);
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// Lookahead at #2. If it is a KleenOp, then #1 is a separator.
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let is_1_sep = if let Some(&tokenstream::TokenTree::Token(_, ref tok2)) = input.peek() {
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kleene_op(tok2).is_some()
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} else {
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false
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};
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if is_1_sep {
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// #1 is a separator and #2 should be a KleepeOp::*
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// (N.B. We need to advance the input iterator.)
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match parse_kleene_op(input, span) {
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// #2 is a KleeneOp (this is the only valid option) :)
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Ok(Ok(op)) if op == KleeneOp::ZeroOrOne => {
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if !features.macro_at_most_once_rep
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&& !attr::contains_name(attrs, "allow_internal_unstable")
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{
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let explain = feature_gate::EXPLAIN_MACRO_AT_MOST_ONCE_REP;
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emit_feature_err(
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sess,
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"macro_at_most_once_rep",
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span,
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GateIssue::Language,
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explain,
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);
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}
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return (Some(token::Question), op);
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}
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Ok(Ok(op)) => return (Some(token::Question), op),
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// #2 is a random token (this is an error) :(
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Ok(Err((_, span))) => span,
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// #2 is not even a token at all :(
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Err(span) => span,
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}
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} else {
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if !features.macro_at_most_once_rep
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&& !attr::contains_name(attrs, "allow_internal_unstable")
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{
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let explain = feature_gate::EXPLAIN_MACRO_AT_MOST_ONCE_REP;
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emit_feature_err(
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sess,
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"macro_at_most_once_rep",
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span,
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GateIssue::Language,
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explain,
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);
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}
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// #2 is a random tree and #1 is KleeneOp::ZeroOrOne
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return (None, op);
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}
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}
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// #1 is a separator followed by #2, a KleeneOp
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Ok(Err((tok, span))) => match parse_kleene_op(input, span) {
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@ -421,11 +467,8 @@ where
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GateIssue::Language,
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explain,
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);
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} else {
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sess.span_diagnostic
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.span_err(span, "`?` macro repetition does not allow a separator");
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}
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return (None, op);
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return (Some(tok), op);
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}
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Ok(Ok(op)) => return (Some(tok), op),
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@ -440,7 +483,9 @@ where
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Err(span) => span,
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};
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if !features.macro_at_most_once_rep && !attr::contains_name(attrs, "allow_internal_unstable") {
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if !features.macro_at_most_once_rep
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&& !attr::contains_name(attrs, "allow_internal_unstable")
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{
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sess.span_diagnostic
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.span_err(span, "expected one of: `*`, `+`, or `?`");
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} else {
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@ -32,13 +32,25 @@ macro_rules! foo {
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} }
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}
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macro_rules! baz {
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($($a:ident),? ; $num:expr) => { { // comma separator is meaningless for `?`
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let mut x = 0;
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$(
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x += $a;
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)?
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assert_eq!(x, $num);
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} }
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}
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macro_rules! barplus {
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($($a:ident)?+ ; $num:expr) => { {
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let mut x = 0;
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$(
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x += $a;
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)?
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)+
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assert_eq!(x, $num);
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} }
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@ -50,7 +62,7 @@ macro_rules! barstar {
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$(
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x += $a;
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)?
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)*
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assert_eq!(x, $num);
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} }
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@ -62,10 +74,15 @@ pub fn main() {
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// accept 0 or 1 repetitions
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foo!( ; 0);
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foo!(a ; 1);
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baz!( ; 0);
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baz!(a ; 1);
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// Make sure using ? as a separator works as before
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barplus!(+ ; 0);
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barplus!(a + ; 1);
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barstar!(* ; 0);
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barstar!(a * ; 1);
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barplus!(a ; 1);
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barplus!(a?a ; 2);
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barplus!(a?a?a ; 3);
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barstar!( ; 0);
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barstar!(a ; 1);
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barstar!(a?a ; 2);
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barstar!(a?a?a ; 3);
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}
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@ -8,26 +8,30 @@
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Tests the behavior of various Kleene operators in macros with respect to `?` terminals. In
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// particular, `?` in the position of a separator and of a Kleene operator is tested.
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// The logic for parsing Kleene operators in macros has a special case to disambiguate `?`.
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// Specifically, `$(pat)?` is the ZeroOrOne operator whereas `$(pat)?+` or `$(pat)?*` are the
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// ZeroOrMore and OneOrMore operators using `?` as a separator. These tests are intended to
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// exercise that logic in the macro parser.
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//
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// Moreover, we also throw in some tests for using a separator with `?`, which is meaningless but
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// included for consistency with `+` and `*`.
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//
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// This test focuses on error cases.
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#![feature(macro_at_most_once_rep)]
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// should match `` and `a`
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macro_rules! foo {
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($(a)?) => {}
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}
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macro_rules! baz {
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($(a),?) => {} //~ ERROR `?` macro repetition does not allow a separator
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($(a),?) => {} // comma separator is meaningless for `?`
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}
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// should match `+` and `a+`
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macro_rules! barplus {
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($(a)?+) => {}
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}
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// should match `*` and `a*`
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macro_rules! barstar {
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($(a)?*) => {}
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}
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@ -36,14 +40,14 @@ pub fn main() {
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foo!(a?a?a); //~ ERROR no rules expected the token `?`
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foo!(a?a); //~ ERROR no rules expected the token `?`
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foo!(a?); //~ ERROR no rules expected the token `?`
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baz!(a?a?a); //~ ERROR no rules expected the token `?`
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baz!(a?a); //~ ERROR no rules expected the token `?`
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baz!(a?); //~ ERROR no rules expected the token `?`
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baz!(a,); //~ ERROR unexpected end of macro invocation
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baz!(a?a?a,); //~ ERROR no rules expected the token `?`
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baz!(a?a,); //~ ERROR no rules expected the token `?`
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baz!(a?,); //~ ERROR no rules expected the token `?`
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barplus!(); //~ ERROR unexpected end of macro invocation
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barstar!(); //~ ERROR unexpected end of macro invocation
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barplus!(a?); //~ ERROR no rules expected the token `?`
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barplus!(a); //~ ERROR unexpected end of macro invocation
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barstar!(a?); //~ ERROR no rules expected the token `?`
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barstar!(a); //~ ERROR unexpected end of macro invocation
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barplus!(+); // ok
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barstar!(*); // ok
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barplus!(a+); // ok
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barstar!(a*); // ok
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barplus!(a?); //~ ERROR unexpected end of macro invocation
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barstar!(a?); //~ ERROR unexpected end of macro invocation
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}
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@ -1,62 +1,80 @@
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error: `?` macro repetition does not allow a separator
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--> $DIR/macro-at-most-once-rep-ambig.rs:22:10
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LL | ($(a),?) => {} //~ ERROR `?` macro repetition does not allow a separator
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:36:11
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--> $DIR/macro-at-most-once-rep-ambig.rs:40:11
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LL | foo!(a?a?a); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:37:11
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--> $DIR/macro-at-most-once-rep-ambig.rs:41:11
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LL | foo!(a?a); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:38:11
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--> $DIR/macro-at-most-once-rep-ambig.rs:42:11
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LL | foo!(a?); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:43:11
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LL | baz!(a?a?a); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:44:11
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LL | baz!(a?a); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:45:11
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LL | baz!(a?); //~ ERROR no rules expected the token `?`
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| ^
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error: unexpected end of macro invocation
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--> $DIR/macro-at-most-once-rep-ambig.rs:39:5
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--> $DIR/macro-at-most-once-rep-ambig.rs:46:11
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LL | baz!(a,); //~ ERROR unexpected end of macro invocation
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:47:11
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LL | baz!(a?a?a,); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:48:11
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LL | baz!(a?a,); //~ ERROR no rules expected the token `?`
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:49:11
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LL | baz!(a?,); //~ ERROR no rules expected the token `?`
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| ^
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error: unexpected end of macro invocation
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--> $DIR/macro-at-most-once-rep-ambig.rs:50:5
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LL | barplus!(); //~ ERROR unexpected end of macro invocation
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| ^^^^^^^^^^^
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error: unexpected end of macro invocation
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--> $DIR/macro-at-most-once-rep-ambig.rs:40:5
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--> $DIR/macro-at-most-once-rep-ambig.rs:51:15
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LL | barstar!(); //~ ERROR unexpected end of macro invocation
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| ^^^^^^^^^^^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:41:15
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LL | barplus!(a?); //~ ERROR no rules expected the token `?`
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LL | barplus!(a?); //~ ERROR unexpected end of macro invocation
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| ^
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error: unexpected end of macro invocation
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--> $DIR/macro-at-most-once-rep-ambig.rs:42:14
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--> $DIR/macro-at-most-once-rep-ambig.rs:52:15
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LL | barplus!(a); //~ ERROR unexpected end of macro invocation
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| ^
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error: no rules expected the token `?`
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--> $DIR/macro-at-most-once-rep-ambig.rs:43:15
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LL | barstar!(a?); //~ ERROR no rules expected the token `?`
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LL | barstar!(a?); //~ ERROR unexpected end of macro invocation
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| ^
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error: unexpected end of macro invocation
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--> $DIR/macro-at-most-once-rep-ambig.rs:44:14
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LL | barstar!(a); //~ ERROR unexpected end of macro invocation
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| ^
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error: aborting due to 10 previous errors
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error: aborting due to 13 previous errors
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