Merge pull request #821 from adriaanm/64acb46ab7

SI-5830 switches: support guards, unreachability

9 files changed, 109 insertions, 35 deletions

diff --git a/test/files/neg/switch.check b/test/files/neg/switch.check
index 8955c94b32..e4730b6459 100644
--- a/test/files/neg/switch.check
+++ b/test/files/neg/switch.check
@@ -1,10 +1,7 @@
-switch.scala:28: error: could not emit switch for @switch annotated match
-  def fail1(c: Char) = (c: @switch) match {
-                            ^
 switch.scala:38: error: could not emit switch for @switch annotated match
   def fail2(c: Char) = (c: @switch @unchecked) match {
                                     ^
 switch.scala:45: error: could not emit switch for @switch annotated match
   def fail3(c: Char) = (c: @unchecked @switch) match {
                                        ^
-three errors found
+two errors found
diff --git a/test/files/neg/switch.scala b/test/files/neg/switch.scala
index a3dfd869d6..198583fe41 100644
--- a/test/files/neg/switch.scala
+++ b/test/files/neg/switch.scala
@@ -24,8 +24,8 @@ object Main {
     case _                => false
   }
   
-  // has a guard
-  def fail1(c: Char) = (c: @switch) match {
+  // has a guard, but since SI-5830 that's ok
+  def succ_guard(c: Char) = (c: @switch) match {
     case 'A' | 'B' | 'C'  => true
     case x if x == 'A'    => true
     case _                => false
diff --git a/test/files/neg/t5830.check b/test/files/neg/t5830.check
new file mode 100644
index 0000000000..85cb84378f
--- /dev/null
+++ b/test/files/neg/t5830.check
@@ -0,0 +1,4 @@
+t5830.scala:6: error: unreachable code
+    case 'a' => println("b") // unreachable
+                       ^
+one error found
diff --git a/test/files/neg/t5830.flags b/test/files/neg/t5830.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/t5830.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t5830.scala b/test/files/neg/t5830.scala
new file mode 100644
index 0000000000..c2df3dec8b
--- /dev/null
+++ b/test/files/neg/t5830.scala
@@ -0,0 +1,9 @@
+import scala.annotation.switch
+
+class Test {
+  def unreachable(ch: Char) = (ch: @switch) match {
+    case 'a' => println("b") // ok
+    case 'a' => println("b") // unreachable
+    case 'c' =>
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/inline-ex-handlers.check b/test/files/run/inline-ex-handlers.check
index 708fcc6985..7d96c447b0 100644
--- a/test/files/run/inline-ex-handlers.check
+++ b/test/files/run/inline-ex-handlers.check
@@ -20,14 +20,14 @@
 409c408,417
 <     103	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 17
 >     
 >   17: 
->     101	LOAD_LOCAL(value ex5)
->     101	STORE_LOCAL(value x3)
->     101	SCOPE_ENTER value x3
->     106	LOAD_LOCAL(value x3)
+>     101	LOAD_LOCAL(value ex6)
+>     101	STORE_LOCAL(value x4)
+>     101	SCOPE_ENTER value x4
+>     106	LOAD_LOCAL(value x4)
 >     106	IS_INSTANCE REF(class MyException)
 >     106	CZJUMP (BOOL)NE ? 5 : 11
 422,424d429
@@ -125,29 +125,29 @@
 737c786,793
 <     172	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 32
 >     
 >   32: 
->     170	LOAD_LOCAL(value ex5)
->     170	STORE_LOCAL(value x3)
->     170	SCOPE_ENTER value x3
+>     170	LOAD_LOCAL(value ex6)
+>     170	STORE_LOCAL(value x4)
+>     170	SCOPE_ENTER value x4
 >     170	JUMP 18
 793c849,850
 <     177	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 33
 797c854,861
 <     170	THROW(Throwable)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 33
 >     
 >   33: 
->     169	LOAD_LOCAL(value ex5)
->     169	STORE_LOCAL(value x3)
->     169	SCOPE_ENTER value x3
+>     169	LOAD_LOCAL(value ex6)
+>     169	STORE_LOCAL(value x4)
+>     169	SCOPE_ENTER value x4
 >     169	JUMP 5
 830c894,895
 <     182	THROW(MyException)
@@ -188,13 +188,13 @@
 909c988,995
 <     124	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 20
 >     
 >   20: 
->     122	LOAD_LOCAL(value ex5)
->     122	STORE_LOCAL(value x3)
->     122	SCOPE_ENTER value x3
+>     122	LOAD_LOCAL(value ex6)
+>     122	STORE_LOCAL(value x4)
+>     122	SCOPE_ENTER value x4
 >     122	JUMP 7
 969c1055
 <     catch (IllegalArgumentException) in ArrayBuffer(6, 7, 8, 11, 14, 16, 17, 19) starting at: 3
@@ -207,14 +207,14 @@
 1019c1105,1114
 <     148	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 20
 >     
 >   20: 
->     145	LOAD_LOCAL(value ex5)
->     145	STORE_LOCAL(value x3)
->     145	SCOPE_ENTER value x3
->     154	LOAD_LOCAL(value x3)
+>     145	LOAD_LOCAL(value ex6)
+>     145	STORE_LOCAL(value x4)
+>     145	SCOPE_ENTER value x4
+>     154	LOAD_LOCAL(value x4)
 >     154	IS_INSTANCE REF(class MyException)
 >     154	CZJUMP (BOOL)NE ? 5 : 11
 1040,1042d1134
@@ -243,19 +243,19 @@
 1372c1471,1472
 <     203	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 20
 1392c1492,1501
 <     209	THROW(MyException)
 ---
->     ?	STORE_LOCAL(value ex5)
+>     ?	STORE_LOCAL(value ex6)
 >     ?	JUMP 20
 >     
 >   20: 
->     200	LOAD_LOCAL(value ex5)
->     200	STORE_LOCAL(value x3)
->     200	SCOPE_ENTER value x3
->     212	LOAD_LOCAL(value x3)
+>     200	LOAD_LOCAL(value ex6)
+>     200	STORE_LOCAL(value x4)
+>     200	SCOPE_ENTER value x4
+>     212	LOAD_LOCAL(value x4)
 >     212	IS_INSTANCE REF(class MyException)
 >     212	CZJUMP (BOOL)NE ? 5 : 11
 1405,1407d1513
diff --git a/test/files/run/t5830.check b/test/files/run/t5830.check
new file mode 100644
index 0000000000..675387eb8e
--- /dev/null
+++ b/test/files/run/t5830.check
@@ -0,0 +1,6 @@
+a with oef
+a with oef
+a
+def with oef
+def
+default
diff --git a/test/files/run/t5830.flags b/test/files/run/t5830.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/run/t5830.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/run/t5830.scala b/test/files/run/t5830.scala
new file mode 100644
index 0000000000..5d808bfa28
--- /dev/null
+++ b/test/files/run/t5830.scala
@@ -0,0 +1,56 @@
+import scala.annotation.switch
+
+object Test extends App {
+  // TODO: should not emit a switch
+  // def noSwitch(ch: Char, eof: Boolean) = (ch: @switch) match {
+  //   case 'a' if eof => println("a with oef") // then branch
+  // }
+
+  def onlyThen(ch: Char, eof: Boolean) = (ch: @switch) match {
+    case 'a' if eof => println("a with oef") // then branch
+    case 'c' =>
+  }
+
+  def ifThenElse(ch: Char, eof: Boolean) = (ch: @switch) match {
+    case 'a' if eof => println("a with oef") // then branch
+    case 'a' if eof => println("a with oef2") // unreachable, but the analysis is not that sophisticated
+    case 'a' => println("a") // else-branch
+    case 'c' =>
+  }
+
+  def defaultUnguarded(ch: Char, eof: Boolean) = (ch: @switch) match {
+    case ' ' if eof => println("spacey oef")
+    case _ => println("default")
+  }
+
+  def defaults(ch: Char, eof: Boolean) = (ch: @switch) match {
+    case _ if eof => println("def with oef") // then branch
+    case _ if eof => println("def with oef2") // unreachable, but the analysis is not that sophisticated
+    case _ => println("def") // else-branch
+  }
+
+  // test binders in collapsed cases (no need to run, it's "enough" to know it doesn't crash the compiler)
+  def guard(x: Any): Boolean = true
+  def testBinders =
+    try { println("") } // work around SI-6015
+    catch {
+      case _ if guard(null) =>
+      case x if guard(x) => throw x
+    }
+
+  // def unreachable(ch: Char) = (ch: @switch) match {
+  //   case 'a' => println("b") // ok
+  //   case 'a' => println("b") // unreachable
+  //   case 'c' =>
+  // }
+
+  // noSwitch('a', true)
+  onlyThen('a', true)       // 'a with oef'
+  ifThenElse('a', true)     // 'a with oef'
+  ifThenElse('a', false)    // 'a'
+  defaults('a', true)       // 'def with oef'
+  defaults('a', false)      // 'def'
+
+  // test that it jumps to default case, no match error
+  defaultUnguarded(' ', false) // default
+}
\ No newline at end of file