Merge pull request #2337 from retronym/ticket/7110-2

SI-7110 Warn about naked try without catch/finally

4 files changed, 20 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 36542cc9d9..0be7192471 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -5008,6 +5008,13 @@ trait Typers extends Adaptations with Tags {
       }
 
       def typedTry(tree: Try) = {
+        tree match {
+          case Try(_, Nil, EmptyTree) =>
+            if (!isPastTyper) context.warning(tree.pos,
+              "A try without a catch or finally is equivalent to putting its body in a block; no exceptions are handled.")
+          case _ =>
+        }
+
         var block1 = typed(tree.block, pt)
         var catches1 = typedCases(tree.catches, ThrowableClass.tpe, pt)
 
diff --git a/test/files/neg/t7110.check b/test/files/neg/t7110.check
new file mode 100644
index 0000000000..e484dc4325
--- /dev/null
+++ b/test/files/neg/t7110.check
@@ -0,0 +1,6 @@
+t7110.scala:2: warning: A try without a catch or finally is equivalent to putting its body in a block; no exceptions are handled.
+  try { ??? } // warn
+  ^
+error: No warnings can be incurred under -Xfatal-warnings.
+one warning found
+one error found
diff --git a/test/files/neg/t7110.flags b/test/files/neg/t7110.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/t7110.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t7110.scala b/test/files/neg/t7110.scala
new file mode 100644
index 0000000000..79ac325216
--- /dev/null
+++ b/test/files/neg/t7110.scala
@@ -0,0 +1,6 @@
+object Test {
+  try { ??? } // warn
+
+  try { ??? } finally ??? // no warn
+  try { ??? } catch { case _: Throwable => } // no warn
+}