SI-9415 Turn on SAM by default

Initial work to change settings and test by Svyatoslav Ilinskiy
Thanks!

To avoid cycles during overload resolution (which showed up
during bootstrapping), and to improve performance, I've guarded
the detection of SAM types in `isCompatible` to cases when the
LHS is potentially compatible.

16 files changed, 3 insertions, 18 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
index c6c9545391..807e0cc72f 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
@@ -262,7 +262,7 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
       else {
         // Phase travel necessary. For example, nullary methods (getter of an abstract val) get an
         // empty parameter list in later phases and would therefore be picked as SAM.
-        val samSym = exitingPickler(definitions.findSam(classSym.tpe))
+        val samSym = exitingPickler(definitions.samOf(classSym.tpe))
         if (samSym == NoSymbol) None
         else Some(samSym.javaSimpleName.toString + methodSymToDescriptor(samSym))
       }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index 684cf788a4..84cf3c6475 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -295,7 +295,7 @@ trait Infer extends Checkable {
         && !isByNameParamType(tp)
         && isCompatible(tp, dropByName(pt))
       )
-      def isCompatibleSam(tp: Type, pt: Type): Boolean = {
+      def isCompatibleSam(tp: Type, pt: Type): Boolean = (definitions.isFunctionType(tp) || tp.isInstanceOf[MethodType] || tp.isInstanceOf[PolyType]) &&  {
         val samFun = typer.samToFunctionType(pt)
         (samFun ne NoType) && isCompatible(tp, samFun)
       }
diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala
index 48caf3081a..a031f4f797 100644
--- a/src/reflect/scala/reflect/internal/Definitions.scala
+++ b/src/reflect/scala/reflect/internal/Definitions.scala
@@ -809,9 +809,7 @@ trait Definitions extends api.StandardDefinitions {
      * The class defining the method is a supertype of `tp` that
      * has a public no-arg primary constructor.
      */
-    def samOf(tp: Type): Symbol = if (!settings.Xexperimental) NoSymbol else findSam(tp)
-
-    def findSam(tp: Type): Symbol = {
+    def samOf(tp: Type): Symbol = {
       // if tp has a constructor, it must be public and must not take any arguments
       // (not even an implicit argument list -- to keep it simple for now)
       val tpSym  = tp.typeSymbol
diff --git a/test/files/neg/sammy_error_exist_no_crash.flags b/test/files/neg/sammy_error_exist_no_crash.flags
deleted file mode 100644
index e1b37447c9..0000000000
--- a/test/files/neg/sammy_error_exist_no_crash.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
\ No newline at end of file
diff --git a/test/files/neg/sammy_restrictions.flags b/test/files/neg/sammy_restrictions.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/neg/sammy_restrictions.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/neg/sammy_wrong_arity.flags b/test/files/neg/sammy_wrong_arity.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/neg/sammy_wrong_arity.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_exist.flags b/test/files/pos/sammy_exist.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_exist.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_overload.flags b/test/files/pos/sammy_overload.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_overload.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_override.flags b/test/files/pos/sammy_override.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_override.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_poly.flags b/test/files/pos/sammy_poly.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_poly.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_scope.flags b/test/files/pos/sammy_scope.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_scope.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_single.flags b/test/files/pos/sammy_single.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_single.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/sammy_twice.flags b/test/files/pos/sammy_twice.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/sammy_twice.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/pos/t8310.flags b/test/files/pos/t8310.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/pos/t8310.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/run/sammy_java8.flags b/test/files/run/sammy_java8.flags
deleted file mode 100644
index 48fd867160..0000000000
--- a/test/files/run/sammy_java8.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
diff --git a/test/files/run/sammy_repeated.flags b/test/files/run/sammy_repeated.flags
deleted file mode 100644
index e1b37447c9..0000000000
--- a/test/files/run/sammy_repeated.flags
+++ /dev/null
@@ -1 +0,0 @@
--Xexperimental
\ No newline at end of file