1 files changed, 46 insertions, 0 deletions
diff --git a/src/test/ui/macros/ambiguity-legacy-vs-modern.rs b/src/test/ui/macros/ambiguity-legacy-vs-modern.rs
new file mode 100644
index 000000000..216b9dd05
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+++ b/src/test/ui/macros/ambiguity-legacy-vs-modern.rs
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+// Some non-controversial subset of ambiguities "modern macro name" vs "macro_rules"
+// is disambiguated to mitigate regressions from macro modularization.
+// Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
+
+#![feature(decl_macro)]
+
+fn same_unnamed_mod() {
+    macro m() { 0 }
+
+    macro_rules! m { () => (()) }
+
+    m!() // OK
+}
+
+fn nested_unnamed_mod() {
+    macro m() { 0 }
+
+    {
+        macro_rules! m { () => (()) }
+
+        m!() // OK
+    }
+}
+
+fn nested_unnamed_mod_fail() {
+    macro_rules! m { () => (()) }
+
+    {
+        macro m() { 0 }
+
+        m!() //~ ERROR `m` is ambiguous
+    }
+}
+
+fn nexted_named_mod_fail() {
+    macro m() { 0 }
+
+    #[macro_use]
+    mod inner {
+        macro_rules! m { () => (()) }
+    }
+
+    m!() //~ ERROR `m` is ambiguous
+}
+
+fn main() {}