Clarify why we emit ATHROW after expressions of type Nothing

Tests for emitting expressions of type Nothing.

7 files changed, 187 insertions, 0 deletions

diff --git a/test/files/run/nothingTypeDce.flags b/test/files/run/nothingTypeDce.flags
new file mode 100644
index 0000000000..d85321ca0e
--- /dev/null
+++ b/test/files/run/nothingTypeDce.flags
@@ -0,0 +1 @@
+-target:jvm-1.6 -Ybackend:GenBCode -Yopt:unreachable-code
diff --git a/test/files/run/nothingTypeDce.scala b/test/files/run/nothingTypeDce.scala
new file mode 100644
index 0000000000..4b9d934eac
--- /dev/null
+++ b/test/files/run/nothingTypeDce.scala
@@ -0,0 +1,61 @@
+// See comment in BCodeBodyBuilder
+
+// -target:jvm-1.6 -Ybackend:GenBCode -Yopt:unreachable-code
+// target enables stack map frames generation
+
+class C {
+  // can't just emit a call to ???, that returns value of type Nothing$ (not Int).
+  def f1: Int = ???
+
+  def f2: Int = throw new Error("")
+
+  def f3(x: Boolean) = {
+    var y = 0
+    // cannot assign an object of type Nothing$ to Int
+    if (x) y = ???
+    else   y = 1
+    y
+  }
+
+  def f4(x: Boolean) = {
+    var y = 0
+    // tests that whatever is emitted after the throw is valid (what? depends on opts, presence of stack map frames)
+    if (x) y = throw new Error("")
+    else   y = 1
+    y
+  }
+
+  def f5(x: Boolean) = {
+    // stack heights need to be the smae. ??? looks to the jvm like returning a value of
+    // type Nothing$, need to drop or throw it.
+    println(
+      if (x) { ???; 10 }
+      else 20
+    )
+  }
+
+  def f6(x: Boolean) = {
+    println(
+      if (x) { throw new Error(""); 10 }
+      else 20
+    )
+  }
+
+  def f7(x: Boolean) = {
+    println(
+      if (x) throw new Error("")
+      else 20
+    )
+  }
+
+  def f8(x: Boolean) = {
+    println(
+      if (x) throw new Error("")
+      else 20
+    )
+  }
+}
+
+object Test extends App {
+  new C()
+}
diff --git a/test/files/run/nothingTypeNoFramesNoDce.check b/test/files/run/nothingTypeNoFramesNoDce.check
new file mode 100644
index 0000000000..b1d08b45ff
--- /dev/null
+++ b/test/files/run/nothingTypeNoFramesNoDce.check
@@ -0,0 +1 @@
+warning: -target:jvm-1.5 is deprecated: use target for Java 1.6 or above.
diff --git a/test/files/run/nothingTypeNoFramesNoDce.flags b/test/files/run/nothingTypeNoFramesNoDce.flags
new file mode 100644
index 0000000000..a035c86179
--- /dev/null
+++ b/test/files/run/nothingTypeNoFramesNoDce.flags
@@ -0,0 +1 @@
+-target:jvm-1.5 -Ybackend:GenBCode -Yopt:l:none -deprecation
diff --git a/test/files/run/nothingTypeNoFramesNoDce.scala b/test/files/run/nothingTypeNoFramesNoDce.scala
new file mode 100644
index 0000000000..3d1298303a
--- /dev/null
+++ b/test/files/run/nothingTypeNoFramesNoDce.scala
@@ -0,0 +1,61 @@
+// See comment in BCodeBodyBuilder
+
+// -target:jvm-1.5 -Ybackend:GenBCode -Yopt:l:none
+// target disables stack map frame generation. in this mode, the ClssWriter just emits dead code as is.
+
+class C {
+  // can't just emit a call to ???, that returns value of type Nothing$ (not Int).
+  def f1: Int = ???
+
+  def f2: Int = throw new Error("")
+
+  def f3(x: Boolean) = {
+    var y = 0
+    // cannot assign an object of type Nothing$ to Int
+    if (x) y = ???
+    else   y = 1
+    y
+  }
+
+  def f4(x: Boolean) = {
+    var y = 0
+    // tests that whatever is emitted after the throw is valid (what? depends on opts, presence of stack map frames)
+    if (x) y = throw new Error("")
+    else   y = 1
+    y
+  }
+
+  def f5(x: Boolean) = {
+    // stack heights need to be the smae. ??? looks to the jvm like returning a value of
+    // type Nothing$, need to drop or throw it.
+    println(
+      if (x) { ???; 10 }
+      else 20
+    )
+  }
+
+  def f6(x: Boolean) = {
+    println(
+      if (x) { throw new Error(""); 10 }
+      else 20
+    )
+  }
+
+  def f7(x: Boolean) = {
+    println(
+      if (x) throw new Error("")
+      else 20
+    )
+  }
+
+  def f8(x: Boolean) = {
+    println(
+      if (x) throw new Error("")
+      else 20
+    )
+  }
+}
+
+object Test extends App {
+  new C()
+}
diff --git a/test/files/run/nothingTypeNoOpt.flags b/test/files/run/nothingTypeNoOpt.flags
new file mode 100644
index 0000000000..b3b518051b
--- /dev/null
+++ b/test/files/run/nothingTypeNoOpt.flags
@@ -0,0 +1 @@
+-target:jvm-1.6 -Ybackend:GenBCode -Yopt:l:none
diff --git a/test/files/run/nothingTypeNoOpt.scala b/test/files/run/nothingTypeNoOpt.scala
new file mode 100644
index 0000000000..5c5a20fa3b
--- /dev/null
+++ b/test/files/run/nothingTypeNoOpt.scala
@@ -0,0 +1,61 @@
+// See comment in BCodeBodyBuilder
+
+// -target:jvm-1.6 -Ybackend:GenBCode -Yopt:l:none
+// target enables stack map frame generation
+
+class C {
+  // can't just emit a call to ???, that returns value of type Nothing$ (not Int).
+  def f1: Int = ???
+
+  def f2: Int = throw new Error("")
+
+  def f3(x: Boolean) = {
+    var y = 0
+    // cannot assign an object of type Nothing$ to Int
+    if (x) y = ???
+    else   y = 1
+    y
+  }
+
+  def f4(x: Boolean) = {
+    var y = 0
+    // tests that whatever is emitted after the throw is valid (what? depends on opts, presence of stack map frames)
+    if (x) y = throw new Error("")
+    else   y = 1
+    y
+  }
+
+  def f5(x: Boolean) = {
+    // stack heights need to be the smae. ??? looks to the jvm like returning a value of
+    // type Nothing$, need to drop or throw it.
+    println(
+      if (x) { ???; 10 }
+      else 20
+    )
+  }
+
+  def f6(x: Boolean) = {
+    println(
+      if (x) { throw new Error(""); 10 }
+      else 20
+    )
+  }
+
+  def f7(x: Boolean) = {
+    println(
+      if (x) throw new Error("")
+      else 20
+    )
+  }
+
+  def f8(x: Boolean) = {
+    println(
+      if (x) throw new Error("")
+      else 20
+    )
+  }
+}
+
+object Test extends App {
+  new C()
+}