From 2064372659156e2637eac4d092321818a30abb41 Mon Sep 17 00:00:00 2001 From: Paul Phillips Date: Mon, 2 Jan 2012 11:48:22 -0800 Subject: Better error reporting regarding main methods. Now notices most things which look like main methods and says something useful if they aren't usable as entry points. Closes SI-4749. --- test/files/neg/main1.check | 20 ++++++++++---------- test/files/neg/t4749.check | 28 ++++++++++++++++++++++++++++ test/files/neg/t4749.flags | 1 + test/files/neg/t4749.scala | 44 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 83 insertions(+), 10 deletions(-) create mode 100644 test/files/neg/t4749.check create mode 100644 test/files/neg/t4749.flags create mode 100644 test/files/neg/t4749.scala (limited to 'test/files/neg') diff --git a/test/files/neg/main1.check b/test/files/neg/main1.check index 734c78e54d..1a7a13e1e9 100644 --- a/test/files/neg/main1.check +++ b/test/files/neg/main1.check @@ -1,25 +1,25 @@ -main1.scala:3: error: Foo has a main method, but foo1.Foo will not be a runnable program. - Its companion is a trait, which means no static forwarder can be generated. +main1.scala:3: error: Foo has a main method with parameter type Array[String], but foo1.Foo will not be a runnable program. + Reason: companion is a trait, which means no static forwarder can be generated. object Foo { // companion is trait ^ -main1.scala:10: error: Foo has a main method, but foo2.Foo will not be a runnable program. - Its companion contains its own main method, which means no static forwarder can be generated. +main1.scala:10: error: Foo has a main method with parameter type Array[String], but foo2.Foo will not be a runnable program. + Reason: companion contains its own main method, which means no static forwarder can be generated. object Foo { // companion has its own main ^ -main1.scala:22: error: Foo has a main method, but foo3.Foo will not be a runnable program. - Its companion contains its own main method (implementation restriction: no main is allowed, regardless of signature), which means no static forwarder can be generated. +main1.scala:22: error: Foo has a main method with parameter type Array[String], but foo3.Foo will not be a runnable program. + Reason: companion contains its own main method (implementation restriction: no main is allowed, regardless of signature), which means no static forwarder can be generated. object Foo { // Companion contains main, but not an interfering main. ^ -main1.scala:31: error: Foo has a main method, but foo4.Foo will not be a runnable program. - Its companion contains its own main method (implementation restriction: no main is allowed, regardless of signature), which means no static forwarder can be generated. +main1.scala:31: error: Foo has a main method with parameter type Array[String], but foo4.Foo will not be a runnable program. + Reason: companion contains its own main method, which means no static forwarder can be generated. object Foo extends Foo { // Inherits main from the class ^ -main1.scala:39: error: Foo has a main method, but foo5.Foo will not be a runnable program. - Its companion contains its own main method (implementation restriction: no main is allowed, regardless of signature), which means no static forwarder can be generated. +main1.scala:39: error: Foo has a main method with parameter type Array[String], but foo5.Foo will not be a runnable program. + Reason: companion contains its own main method, which means no static forwarder can be generated. object Foo extends Foo { // Overrides main from the class ^ diff --git a/test/files/neg/t4749.check b/test/files/neg/t4749.check new file mode 100644 index 0000000000..93ad3935fa --- /dev/null +++ b/test/files/neg/t4749.check @@ -0,0 +1,28 @@ +t4749.scala:2: error: Fail1 has a main method with parameter type Array[String], but bippy.Fail1 will not be a runnable program. + Reason: main method must have exact signature (Array[String])Unit + object Fail1 { + ^ +t4749.scala:6: error: Fail2 has a main method with parameter type Array[String], but bippy.Fail2 will not be a runnable program. + Reason: main methods cannot be generic. + object Fail2 { + ^ +t4749.scala:13: error: Fail3 has a main method with parameter type Array[String], but bippy.Fail3 will not be a runnable program. + Reason: main methods cannot refer to type parameters or abstract types. + object Fail3 extends Bippy[Unit] { } + ^ +t4749.scala:16: error: Fail4 has a main method with parameter type Array[String], but bippy.Fail4 will not be a runnable program. + Reason: companion is a trait, which means no static forwarder can be generated. + + object Fail4 { + ^ +t4749.scala:21: error: Fail5 has a main method with parameter type Array[String], but bippy.Fail5 will not be a runnable program. + Reason: companion contains its own main method, which means no static forwarder can be generated. + + object Fail5 extends Fail5 { } + ^ +t4749.scala:26: error: Fail6 has a main method with parameter type Array[String], but bippy.Fail6 will not be a runnable program. + Reason: companion contains its own main method (implementation restriction: no main is allowed, regardless of signature), which means no static forwarder can be generated. + + object Fail6 { + ^ +6 errors found diff --git a/test/files/neg/t4749.flags b/test/files/neg/t4749.flags new file mode 100644 index 0000000000..e8fb65d50c --- /dev/null +++ b/test/files/neg/t4749.flags @@ -0,0 +1 @@ +-Xfatal-warnings \ No newline at end of file diff --git a/test/files/neg/t4749.scala b/test/files/neg/t4749.scala new file mode 100644 index 0000000000..0973c36097 --- /dev/null +++ b/test/files/neg/t4749.scala @@ -0,0 +1,44 @@ +package bippy { + object Fail1 { + def main(args: Array[String]): Any = () + } + + object Fail2 { + def main[T](args: Array[String]): T = null.asInstanceOf[T] + } + + abstract class Bippy[T] { + def main(args: Array[String]): T = null.asInstanceOf[T] + } + object Fail3 extends Bippy[Unit] { } + + + object Fail4 { + def main(args: Array[String]): Unit = () + } + trait Fail4 { } + + object Fail5 extends Fail5 { } + class Fail5 { + def main(args: Array[String]): Unit = () + } + + object Fail6 { + def main(args: Array[String]): Unit = () + } + class Fail6 { + def main = "bippy" + } + + object Win1 { + def main(args: Array[String]): Unit = () + } + object Win2 extends Bippy[Unit] { + override def main(args: Array[String]): Unit = () + } + trait WinBippy[T] { + def main(args: Array[String]): T = null.asInstanceOf[T] + } + object Win3 extends WinBippy[Unit] { } +} + -- cgit v1.2.3