Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 80 insertions, 0 deletions

diff --git a/tests/ui/macros/issue-57597.rs b/tests/ui/macros/issue-57597.rs
new file mode 100644
index 000000000..ebeb3fe07
--- /dev/null
+++ b/tests/ui/macros/issue-57597.rs
@@ -0,0 +1,80 @@
+// Regression test for #57597.
+//
+// Make sure that nested matchers work correctly rather than causing an infinite loop or crash.
+
+// edition:2018
+
+macro_rules! foo1 {
+    ($($($i:ident)?)+) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo2 {
+    ($($($i:ident)?)*) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo3 {
+    ($($($i:ident)?)?) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo4 {
+    ($($($($i:ident)?)?)?) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo5 {
+    ($($($($i:ident)*)?)?) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo6 {
+    ($($($($i:ident)?)*)?) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo7 {
+    ($($($($i:ident)?)?)*) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo8 {
+    ($($($($i:ident)*)*)?) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo9 {
+    ($($($($i:ident)?)*)*) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo10 {
+    ($($($($i:ident)?)*)+) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo11 {
+    ($($($($i:ident)+)?)*) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+macro_rules! foo12 {
+    ($($($($i:ident)+)*)?) => {};
+    //~^ ERROR repetition matches empty token tree
+}
+
+fn main() {
+    foo1!();
+    foo2!();
+    foo3!();
+    foo4!();
+    foo5!();
+    foo6!();
+    foo7!();
+    foo8!();
+    foo9!();
+    foo10!();
+    foo11!();
+    foo12!();
+}