SI-6276 Warn on def or val that trivially loops infinitely

5 files changed, 45 insertions, 2 deletions

diff --git a/test/files/neg/override.check b/test/files/neg/override.check
index fc152cb3b1..8be98bf4d0 100644
--- a/test/files/neg/override.check
+++ b/test/files/neg/override.check
@@ -1,5 +1,5 @@
 override.scala:9: error: overriding type T in trait A with bounds >: Int <: Int;
  type T in trait B with bounds >: String <: String has incompatible type
-  lazy val x : A with B = x
+  lazy val x : A with B = {println(""); x}
                ^
 one error found
diff --git a/test/files/neg/override.scala b/test/files/neg/override.scala
index 3e589b52e3..7975516061 100755
--- a/test/files/neg/override.scala
+++ b/test/files/neg/override.scala
@@ -6,7 +6,7 @@ trait X {
 
 trait Y extends X {
   trait B { type T >: String <: String }
-  lazy val x : A with B = x
+  lazy val x : A with B = {println(""); x}
   n = "foo"
 }
 
diff --git a/test/files/neg/t6276.check b/test/files/neg/t6276.check
new file mode 100644
index 0000000000..8bd92cf293
--- /dev/null
+++ b/test/files/neg/t6276.check
@@ -0,0 +1,13 @@
+t6276.scala:4: error: method a does nothing other than call itself recursively
+      def a: Any = a // warn
+                   ^
+t6276.scala:5: error: value b does nothing other than call itself recursively
+      val b: Any = b // warn
+                   ^
+t6276.scala:10: error: method a does nothing other than call itself recursively
+      def a: Any = a // warn
+                   ^
+t6276.scala:19: error: method a does nothing other than call itself recursively
+      def a = a // warn
+              ^
+four errors found
diff --git a/test/files/neg/t6276.flags b/test/files/neg/t6276.flags
new file mode 100644
index 0000000000..85d8eb2ba2
--- /dev/null
+++ b/test/files/neg/t6276.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
diff --git a/test/files/neg/t6276.scala b/test/files/neg/t6276.scala
new file mode 100644
index 0000000000..8333618964
--- /dev/null
+++ b/test/files/neg/t6276.scala
@@ -0,0 +1,29 @@
+object Test {
+  def foo(a: Int, b: Int, c: Int) {
+    new {
+      def a: Any = a // warn
+      val b: Any = b // warn
+    }
+
+    def method {
+      // method local
+      def a: Any = a // warn
+    }
+
+    trait T {
+      def a: Any
+    }
+
+    new T {
+      // inherited return type
+      def a = a // warn
+    }
+
+    // no warnings below
+    new {
+      def a: Any = {println(""); a}
+      val b: Any = {println(""); b}
+      def c(i: Int): Any = c(i - 0)
+    }
+  }
+}