refactors handling of parent types

At the moment parser does too much w.r.t handling of parent types.
It checks whether a parent can have value arguments or not and
more importantly, it synthesizes constructors and super calls.

This approach is fundamentally incompatible with upcoming type macros.
Take for example the following two snippets of code:

  `class C extends A(2)`
  `class D extends A(2) with B(3)`

In the first snippet, `A` might be a type macro, therefore the super call
`A.super(2)` eagerly emitted by the parser might be meaningless. In the
second snippet parser will report an error despite that `B` might be
a type macro which expands into a trait.

Unfortunately we cannot simply augment the parser with the `isTypeMacro`
check. This is because to find out whether an identifier refers to a type
macro, one needs to perform a typecheck, which the parser cannot do.

Therefore we need a deep change in how parent types and constructors
are processed by the compiler, which is implemented in this commit.

10 files changed, 13 insertions, 28 deletions

diff --git a/test/files/neg/anyval-anyref-parent.check b/test/files/neg/anyval-anyref-parent.check
index fe20e5de81..8c2aa36583 100644
--- a/test/files/neg/anyval-anyref-parent.check
+++ b/test/files/neg/anyval-anyref-parent.check
@@ -3,7 +3,7 @@ trait Foo2 extends AnyVal // fail
       ^
 anyval-anyref-parent.scala:5: error: Any does not have a constructor
 class Bar1 extends Any      // fail
-           ^
+                   ^
 anyval-anyref-parent.scala:6: error: value class needs to have exactly one public val parameter
 class Bar2(x: Int) extends AnyVal // fail
       ^
diff --git a/test/files/neg/cyclics-import.check b/test/files/neg/cyclics-import.check
index ef355fab0a..be09fca374 100644
--- a/test/files/neg/cyclics-import.check
+++ b/test/files/neg/cyclics-import.check
@@ -3,13 +3,4 @@ Note: this is often due in part to a class depending on a definition nested with
 If applicable, you may wish to try moving some members into another object.
 import User.UserStatus._
             ^
-cyclics-import.scala:12: error: not found: type Value
-    type UserStatus = Value
-                      ^
-cyclics-import.scala:14: error: not found: value Value
-    val Active = Value("1")
-                 ^
-cyclics-import.scala:15: error: not found: value Value
-    val Disabled = Value("2")
-                   ^
-four errors found
+one error found
diff --git a/test/files/neg/names-defaults-neg.check b/test/files/neg/names-defaults-neg.check
index f3c45a6aa0..6f9dc7d127 100644
--- a/test/files/neg/names-defaults-neg.check
+++ b/test/files/neg/names-defaults-neg.check
@@ -100,7 +100,7 @@ Error occurred in an application involving default arguments.
   ^
 names-defaults-neg.scala:86: error: module extending its companion class cannot use default constructor arguments
     object C extends C()
-             ^
+                     ^
 names-defaults-neg.scala:90: error: deprecated parameter name x has to be distinct from any other parameter name (deprecated or not).
   def deprNam1(x: Int, @deprecatedName('x) y: String) = 0
                                            ^
diff --git a/test/files/neg/protected-constructors.check b/test/files/neg/protected-constructors.check
index f137158ed6..e295917050 100644
--- a/test/files/neg/protected-constructors.check
+++ b/test/files/neg/protected-constructors.check
@@ -19,7 +19,4 @@ protected-constructors.scala:15: error: class Foo3 in object Ding cannot be acce
  object Ding in package dingus where target is defined
     class Bar3 extends Ding.Foo3("abc")
                             ^
-protected-constructors.scala:15: error: too many arguments for constructor Object: ()Object
-    class Bar3 extends Ding.Foo3("abc")
-               ^
-5 errors found
+four errors found
diff --git a/test/files/neg/t2148.check b/test/files/neg/t2148.check
index 5113b48e51..27b5dce507 100644
--- a/test/files/neg/t2148.check
+++ b/test/files/neg/t2148.check
@@ -1,4 +1,4 @@
-t2148.scala:9: error: type A is not a stable prefix
+t2148.scala:9: error: A is not a legal prefix for a constructor
   val b = new A with A#A1
                        ^
 one error found
diff --git a/test/files/neg/t409.check b/test/files/neg/t409.check
index 433d64d25d..0edc0d03cd 100644
--- a/test/files/neg/t409.check
+++ b/test/files/neg/t409.check
@@ -1,4 +1,4 @@
-t409.scala:6: error: traits or objects may not have parameters
+t409.scala:6: error: class Case1 needs to be a trait to be mixed in
 class Toto extends Expr with Case1(12);
-                                  ^
+                             ^
 one error found
diff --git a/test/files/neg/t5529.check b/test/files/neg/t5529.check
index 5d2175fa79..da3f84e1ec 100644
--- a/test/files/neg/t5529.check
+++ b/test/files/neg/t5529.check
@@ -4,7 +4,4 @@ t5529.scala:12: error: File is already defined as class File
 t5529.scala:10: error: class type required but test.Test.File found
   sealed class Dir extends File { }
                            ^
-t5529.scala:10: error: test.Test.File does not have a constructor
-  sealed class Dir extends File { }
-                   ^
-three errors found
+two errors found
diff --git a/test/files/neg/t5696.check b/test/files/neg/t5696.check
index 72b7781fc4..e0fb61b839 100644
--- a/test/files/neg/t5696.check
+++ b/test/files/neg/t5696.check
@@ -15,5 +15,5 @@ t5696.scala:38: error: too many argument lists for constructor invocation
       ^
 t5696.scala:46: error: too many argument lists for constructor invocation
   object x extends G(1)(2) {}
-           ^
+                   ^
 6 errors found
diff --git a/test/files/neg/t667.check b/test/files/neg/t667.check
index d4367bc87b..e68c6dea00 100644
--- a/test/files/neg/t667.check
+++ b/test/files/neg/t667.check
@@ -1,4 +1,4 @@
-t667.scala:8: error: class Ni inherits itself
+t667.scala:8: error: illegal cyclic reference involving class Ni
     class Ni extends super.Ni with Ni;
-                                   ^
+             ^
 one error found
diff --git a/test/files/neg/t877.check b/test/files/neg/t877.check
index 5f25bd439c..c3d4ab6584 100644
--- a/test/files/neg/t877.check
+++ b/test/files/neg/t877.check
@@ -1,7 +1,7 @@
 t877.scala:3: error: Invalid literal number
 trait Foo extends A(22A, Bug!) {}
                     ^
-t877.scala:3: error: parents of traits may not have parameters
+t877.scala:3: error: ')' expected but eof found.
 trait Foo extends A(22A, Bug!) {}
-                   ^
+                                 ^
 two errors found