Merge pull request #876 from adriaanm/ticket-6011b

SI-6011 switches: unreachability, guard-free form

9 files changed, 83 insertions, 1 deletions

diff --git a/test/files/neg/t5830.check b/test/files/neg/t5830.check
index 85cb84378f..726fac2a1e 100644
--- a/test/files/neg/t5830.check
+++ b/test/files/neg/t5830.check
@@ -1,4 +1,7 @@
 t5830.scala:6: error: unreachable code
     case 'a' => println("b") // unreachable
                        ^
-one error found
+t5830.scala:4: error: could not emit switch for @switch annotated match
+  def unreachable(ch: Char) = (ch: @switch) match {
+                                    ^
+two errors found
diff --git a/test/files/neg/t6011.check b/test/files/neg/t6011.check
new file mode 100644
index 0000000000..5b5a861e5b
--- /dev/null
+++ b/test/files/neg/t6011.check
@@ -0,0 +1,10 @@
+t6011.scala:4: error: unreachable code
+    case 'a' | 'c' => 1 // unreachable
+                      ^
+t6011.scala:10: error: unreachable code
+    case 'b' | 'a'  => 1 // unreachable
+                       ^
+t6011.scala:8: error: could not emit switch for @switch annotated match
+  def f2(ch: Char): Any = (ch: @annotation.switch) match {
+                                ^
+three errors found
diff --git a/test/files/neg/t6011.flags b/test/files/neg/t6011.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/t6011.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t6011.scala b/test/files/neg/t6011.scala
new file mode 100644
index 0000000000..a36cca7897
--- /dev/null
+++ b/test/files/neg/t6011.scala
@@ -0,0 +1,23 @@
+object Test {
+  def f(ch: Char): Any = ch match {
+    case 'a'  => 1
+    case 'a' | 'c' => 1 // unreachable
+  }
+
+  // won't be compiled to a switch since it has an unreachable (duplicate) case
+  def f2(ch: Char): Any = (ch: @annotation.switch) match {
+    case 'a' | 'b'  => 1
+    case 'b' | 'a'  => 1 // unreachable
+    case _ =>
+  }
+
+  // s'all good
+  def f3(ch: Char): Any = (ch: @annotation.switch) match {
+    case 'a' | 'b'  if (true: Boolean) => 1
+    case 'b' | 'a'  => 1 // ok
+    case _ => // need third case to check switch annotation (two-case switches are always okay to compile to if-then-else)
+  }
+
+
+  def main(args: Array[String]): Unit = f('a')
+}
\ No newline at end of file
diff --git a/test/files/neg/t6048.check b/test/files/neg/t6048.check
new file mode 100644
index 0000000000..051f41877e
--- /dev/null
+++ b/test/files/neg/t6048.check
@@ -0,0 +1,10 @@
+t6048.scala:3: error: unreachable code
+    case _ if false => x // unreachable
+                       ^
+t6048.scala:8: error: unreachable code
+    case _ if false => x // unreachable
+                       ^
+t6048.scala:14: error: unreachable code
+    case 5 if true  => x // unreachable
+                       ^
+three errors found
diff --git a/test/files/neg/t6048.flags b/test/files/neg/t6048.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/t6048.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t6048.scala b/test/files/neg/t6048.scala
new file mode 100644
index 0000000000..803e651d19
--- /dev/null
+++ b/test/files/neg/t6048.scala
@@ -0,0 +1,22 @@
+class A {
+  def f1(x: Int) = x match {
+    case _ if false => x // unreachable
+    case 5          => x
+  }
+
+  def f2(x: Int) = x match {
+    case _ if false => x // unreachable
+    case 5 if true  => x
+  }
+
+  def f3(x: Int) = x match {
+    case _ => x
+    case 5 if true  => x // unreachable
+  }
+
+  def test1(x: Int) = x match {
+    case c if c < 0 => 0
+    case 1          => 1
+    case _          => 2
+  }
+}
diff --git a/test/files/run/t6011b.check b/test/files/run/t6011b.check
new file mode 100644
index 0000000000..00750edc07
--- /dev/null
+++ b/test/files/run/t6011b.check
@@ -0,0 +1 @@
+3
diff --git a/test/files/run/t6011b.scala b/test/files/run/t6011b.scala
new file mode 100644
index 0000000000..3d405e0705
--- /dev/null
+++ b/test/files/run/t6011b.scala
@@ -0,0 +1,11 @@
+object Test extends App {
+  var cond = true
+
+  // should not generate a switch
+  def f(ch: Char): Int = ch match {
+    case 'a' if cond => 1
+    case 'z' | 'a' => 2
+  }
+
+  println(f('a') + f('z')) // 3
+}
\ No newline at end of file