From dabe86db44c97698bc6a4ab2f8923a3f65b151f0 Mon Sep 17 00:00:00 2001
From: mark <markm@cs.wisc.edu>
Date: Tue, 15 Jan 2019 11:31:49 -0600
Subject: [PATCH] update/add tests

---
 src/test/ui/issues/issue-5067.rs      | 37 ++++++++++---
 src/test/ui/issues/issue-57597.rs     | 80 +++++++++++++++++++++++++++
 src/test/ui/issues/issue-57597.stderr | 74 +++++++++++++++++++++++++
 3 files changed, 183 insertions(+), 8 deletions(-)
 create mode 100644 src/test/ui/issues/issue-57597.rs
 create mode 100644 src/test/ui/issues/issue-57597.stderr

diff --git a/src/test/ui/issues/issue-5067.rs b/src/test/ui/issues/issue-5067.rs
index 526a68311462e..616fd09907a2b 100644
--- a/src/test/ui/issues/issue-5067.rs
+++ b/src/test/ui/issues/issue-5067.rs
@@ -1,37 +1,59 @@
 #![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 {
@@ -43,11 +65,10 @@ fn main() {
     let _ = make_vec![a 1, a 2, a 3];
 }
 
-
 // --- Minified Issue --- //
 
 macro_rules! m {
-    ( $()* ) => {}
+    ( $()* ) => {};
     //~^ ERROR repetition matches empty token tree
 }
 
diff --git a/src/test/ui/issues/issue-57597.rs b/src/test/ui/issues/issue-57597.rs
new file mode 100644
index 0000000000000..ebeb3fe07adb4
--- /dev/null
+++ b/src/test/ui/issues/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!();
+}
diff --git a/src/test/ui/issues/issue-57597.stderr b/src/test/ui/issues/issue-57597.stderr
new file mode 100644
index 0000000000000..0a02ac8c499b6
--- /dev/null
+++ b/src/test/ui/issues/issue-57597.stderr
@@ -0,0 +1,74 @@
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:8:7
+   |
+LL |     ($($($i:ident)?)+) => {};
+   |       ^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:13:7
+   |
+LL |     ($($($i:ident)?)*) => {};
+   |       ^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:18:7
+   |
+LL |     ($($($i:ident)?)?) => {};
+   |       ^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:23:7
+   |
+LL |     ($($($($i:ident)?)?)?) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:28:7
+   |
+LL |     ($($($($i:ident)*)?)?) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:33:7
+   |
+LL |     ($($($($i:ident)?)*)?) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:38:7
+   |
+LL |     ($($($($i:ident)?)?)*) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:43:7
+   |
+LL |     ($($($($i:ident)*)*)?) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:48:7
+   |
+LL |     ($($($($i:ident)?)*)*) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:53:7
+   |
+LL |     ($($($($i:ident)?)*)+) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:58:7
+   |
+LL |     ($($($($i:ident)+)?)*) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: repetition matches empty token tree
+  --> $DIR/issue-57597.rs:63:7
+   |
+LL |     ($($($($i:ident)+)*)?) => {};
+   |       ^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 12 previous errors
+