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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/issues/issue-5067.rs | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/src/test/ui/issues/issue-5067.rs b/src/test/ui/issues/issue-5067.rs new file mode 100644 index 000000000..5857a0815 --- /dev/null +++ b/src/test/ui/issues/issue-5067.rs @@ -0,0 +1,75 @@ +#![allow(unused_macros)] + +// Tests that repetition matchers cannot match the empty token tree (since that would be +// ambiguous). + +// edition:2018 + +macro_rules! foo { + ( $()* ) => {}; + //~^ ERROR repetition matches empty token tree + ( $()+ ) => {}; + //~^ ERROR repetition matches empty token tree + ( $()? ) => {}; + //~^ ERROR repetition matches empty token tree + ( $(),* ) => {}; // PASS + ( $(),+ ) => {}; // PASS + // `?` cannot have a separator... + ( [$()*] ) => {}; + //~^ ERROR repetition matches empty token tree + ( [$()+] ) => {}; + //~^ ERROR repetition matches empty token tree + ( [$()?] ) => {}; + //~^ ERROR repetition matches empty token tree + ( [$(),*] ) => {}; // PASS + ( [$(),+] ) => {}; // PASS + // `?` cannot have a separator... + ( $($()* $(),* $(a)* $(a),* )* ) => {}; + //~^ ERROR repetition matches empty token tree + ( $($()* $(),* $(a)* $(a),* )+ ) => {}; + //~^ ERROR repetition matches empty token tree + ( $($()* $(),* $(a)* $(a),* )? ) => {}; + //~^ ERROR repetition matches empty token tree + ( $($()? $(),* $(a)? $(a),* )* ) => {}; + //~^ ERROR repetition matches empty token tree + ( $($()? $(),* $(a)? $(a),* )+ ) => {}; + //~^ ERROR repetition matches empty token tree + ( $($()? $(),* $(a)? $(a),* )? ) => {}; + //~^ ERROR repetition matches empty token tree + ( $(a $(),* $(a)* $(a),* )* ) => {}; // PASS + ( $($(a)+ $(),* $(a)* $(a),* )+ ) => {}; // PASS + ( $($(a)+ $(),* $(a)* $(a),* )? ) => {}; // PASS + + ( $(a $(),* $(a)? $(a),* )* ) => {}; // PASS + ( $($(a)+ $(),* $(a)? $(a),* )+ ) => {}; // PASS + ( $($(a)+ $(),* $(a)? $(a),* )? ) => {}; // PASS + + ( $(a $()+)* ) => {}; + //~^ ERROR repetition matches empty token tree + ( $(a $()*)+ ) => {}; + //~^ ERROR repetition matches empty token tree + ( $(a $()+)? ) => {}; + //~^ ERROR repetition matches empty token tree + ( $(a $()?)+ ) => {}; + //~^ ERROR repetition matches empty token tree +} + +// Original Issue + +macro_rules! make_vec { + (a $e1:expr $($(, a $e2:expr)*)*) => ([$e1 $($(, $e2)*)*]); + //~^ ERROR repetition matches empty token tree +} + +fn main() { + let _ = make_vec![a 1, a 2, a 3]; +} + +// Minified Issue + +macro_rules! m { + ( $()* ) => {}; + //~^ ERROR repetition matches empty token tree +} + +m!(); |