Move tests/init from neg to warn (#19241)

Moves first batch of tests.
PR 1/5 (merge consecutively, per [Nicolas'
suggestion](#18829 (review))

Split up version of #18829

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -225,6 +225,7 @@ class CompilationTests {
     implicit val testGroup: TestGroup = TestGroup("checkInit")
     val options = defaultOptions.and("-Ysafe-init", "-Xfatal-warnings")
     compileFilesInDir("tests/init/neg", options).checkExpectedErrors()
+    compileFilesInDir("tests/init/warn", defaultOptions.and("-Ysafe-init")).checkWarnings()
     compileFilesInDir("tests/init/pos", options).checkCompile()
     compileFilesInDir("tests/init/crash", options.without("-Xfatal-warnings")).checkCompile()
     // The regression test for i12128 has some atypical classpath requirements.

compiler/test/dotty/tools/vulpix/ParallelTesting.scala

@@ -776,7 +776,7 @@ trait ParallelTesting extends RunnerOrchestration { self =>
     end maybeFailureMessage
 
     def getWarnMapAndExpectedCount(files: Seq[JFile]): (HashMap[String, Integer], Int) =
-      val comment = raw"//( *)warn".r
+      val comment = raw"//( *)(nopos-)?warn".r
       val map = new HashMap[String, Integer]()
       var count = 0
       def bump(key: String): Unit =
@@ -787,8 +787,11 @@ trait ParallelTesting extends RunnerOrchestration { self =>
       files.filter(isSourceFile).foreach { file =>
         Using(Source.fromFile(file, StandardCharsets.UTF_8.name)) { source =>
           source.getLines.zipWithIndex.foreach { case (line, lineNbr) =>
-            comment.findAllMatchIn(line).foreach { _ =>
-              bump(s"${file.getPath}:${lineNbr+1}")
+            comment.findAllMatchIn(line).foreach { m =>
+              m.group(2) match
+                case "nopos-" =>
+                  bump("nopos")
+                case _ => bump(s"${file.getPath}:${lineNbr+1}")
             }
           }
         }.get
@@ -809,7 +812,7 @@ trait ParallelTesting extends RunnerOrchestration { self =>
           val key = s"${relativize(srcpos.source.file.toString())}:${srcpos.line + 1}"
           if !seenAt(key) then unexpected += key
         else
-          unpositioned += relativize(srcpos.source.file.toString())
+          if(!seenAt("nopos")) unpositioned += relativize(srcpos.source.file.toString())
 
       reporterWarnings.foreach(sawDiagnostic)
 

tests/init/neg/AbstractFile.scala → tests/init/warn/AbstractFile.scala

@@ -4,6 +4,6 @@ abstract class AbstractFile {
 }
 
 class RemoteFile(url: String) extends AbstractFile {
-	val localFile: String = s"${url.##}.tmp"  // error: usage of `localFile` before it's initialized
+	val localFile: String = s"${url.##}.tmp"  // warn: usage of `localFile` before it's initialized
 	def name: String = localFile
 }

tests/init/neg/alias.scala → tests/init/warn/alias.scala

@@ -1,5 +1,5 @@
 class Foo {
   val self = this
   val x = self.n
-  val n = 10       // error
+  val n = 10       // warn
 }

tests/init/neg/apply.scala → tests/init/warn/apply.scala

@@ -6,7 +6,7 @@ object A:
 
 class B:
   val a = A(this)
-  val a2 = A.foo(this)   // error
+  val a2 = A.foo(this)   // warn
   val a3 = A.bar(this)
 
 // test receiver is ThisRef
@@ -20,7 +20,7 @@ object O:
 
   class B:
     val a = A(this)
-    val a2 = A.foo(this)   // error
+    val a2 = A.foo(this)   // warn
     val a3 = A.bar(this)
 
   val b = new B
@@ -38,7 +38,7 @@ class M(n: N):
 
   class B:
     val a = A(this)
-    val a2 = A.foo(this)   // error
+    val a2 = A.foo(this)   // warn
     val a3 = A.bar(this)
 end M
 

tests/init/neg/apply2.scala → tests/init/warn/apply2.scala

@@ -3,7 +3,7 @@ class O:
     println(n)
 
   class B:
-    val a = A(this)  // error
+    val a = A(this)  // warn
 
   val b = new B
   val n = 10

tests/init/neg/as-instance-of-cold-field-access.scala → tests/init/warn/as-instance-of-cold-field-access.scala

@@ -1,7 +1,7 @@
 final class MyAsInstanceOfClass(o: MyAsInstanceOfClass) {
   val other: MyAsInstanceOfClass = {
     if (o.asInstanceOf[MyAsInstanceOfClass].oRef ne null) o
-    else new MyAsInstanceOfClass(this)  // error
+    else new MyAsInstanceOfClass(this)  // warn
   }
   val oRef = o
 }

tests/init/neg/by-name-error.scala → tests/init/warn/by-name-error.scala

@@ -8,6 +8,6 @@ object Foo {
 }
 
 class A {
-  val foo = implicitly[Foo]     // error
+  val foo = implicitly[Foo]     // warn
   assert(foo eq foo.next)
 }

tests/init/neg/closureLeak.scala → tests/init/warn/closureLeak.scala

@@ -8,6 +8,6 @@ class Outer {
     }
 
     val l: List[A] = List(new A(5), new A(10))
-    l.foreach(a => a.addX(this)) // error
+    l.foreach(a => a.addX(this)) // warn
     val p = 10
 }

tests/init/neg/cold-insert-hot-array.scala → tests/init/warn/cold-insert-hot-array.scala

@@ -3,7 +3,7 @@ object A:
 
 class B {
   var a = new Array[B](2)
-  A.foo(this, a) // error
+  A.foo(this, a) // warn
   println(a(0).i)
   val i = 99
 }

tests/init/neg/cycle-structure.scala → tests/init/warn/cycle-structure.scala

@@ -1,11 +1,11 @@
 case class A(b: B) {
     val x1 = b.x
-    val x = B(this)   // error
+    val x = B(this)   // warn
     val y = x.a
 }
 
 case class B(a: A) {
     val x1 = a.x
-    val x = A(this)   // error
+    val x = A(this)   // warn
     val h = x.b
 }

tests/init/neg/cycle.scala → tests/init/warn/cycle.scala

@@ -1,11 +1,11 @@
 class A(x: B) {
   println(x.b)
-  val a = new B(this)  // error
+  val a = new B(this)  // warn
   val d = a.b
 }
 
 class B(x: A) {
   println(x.a)
-  val b = new A(this)  // error
+  val b = new A(this)  // warn
   val d = b.a
 }

tests/init/neg/default-this.scala → tests/init/warn/default-this.scala

@@ -6,7 +6,7 @@ class A {
 class B extends A {
     def updateThenCompare(c: Int): Boolean = {
         x = c
-        compare() // error
+        compare() // warn
     }
     val result = updateThenCompare(5)
 }

tests/init/neg/early-promote.scala → tests/init/warn/early-promote.scala

@@ -24,7 +24,7 @@ class A { // checking A
     def c = new C
   }
   val b = new B()
-  println(b) // error: the checker simply issue warnings for objects that contain inner classes
+  println(b) // warn: the checker simply issue warnings for objects that contain inner classes
   val af = 42
 }
 

tests/init/warn/early-promote2.scala

@@ -0,0 +1,6 @@
+class M {
+  println(this)       // warn
+  foo()
+  private val a = 5   // warn
+  def foo() = a
+}

tests/init/neg/early-promote3.scala → tests/init/warn/early-promote3.scala

@@ -6,6 +6,6 @@ abstract class A {
 }
 
 class M extends A {
-  def bar() = promote(this)    // error
+  def bar() = promote(this)    // warn
   def promote(m: M) = m.foo()
 }

tests/init/neg/early-promote4.scala → tests/init/warn/early-promote4.scala

@@ -16,5 +16,5 @@ class Outer {
 
 class Dummy {
   val m: Int = n + 4
-  val n: Int = 10     // error
+  val n: Int = 10     // warn
 }

tests/init/neg/early-promote5.scala → tests/init/warn/early-promote5.scala

@@ -14,11 +14,11 @@ class Outer {
 
 class Container {
   val o = new Outer
-  val m = new o.M(this)   // error
+  val m = new o.M(this)   // warn
   val s = "hello"
 }
 
 class Dummy {
   val m: Int = n + 4
-  val n: Int = 10     // error
+  val n: Int = 10     // warn
 }

tests/init/neg/escape1.scala → tests/init/warn/escape1.scala

@@ -1,5 +1,5 @@
 class Foo {
-  val a = Foo.bar(this)   // error
+  val a = Foo.bar(this)   // warn
   val b = "hello"
 }
 

tests/init/neg/features-high-order.scala → tests/init/warn/features-high-order.scala

@@ -4,6 +4,6 @@ abstract class Parent {
 }
 class Child extends Parent {
   val a = f()
-  val b = "hello"           // error
+  val b = "hello"           // warn
   def message: String = b
 }

tests/init/neg/features-linearization.scala → tests/init/warn/features-linearization.scala

@@ -1,5 +1,5 @@
 trait TA {
-  val x = "world" // error
+  val x = "world" // warn
 }
 
 trait TB {

tests/init/neg/features-trees.scala → tests/init/warn/features-trees.scala

@@ -2,5 +2,5 @@ class Trees {
   class ValDef { counter += 1 }
   class EmptyValDef extends ValDef
   val theEmptyValDef = new EmptyValDef
-  private var counter = 0   // error
+  private var counter = 0   // warn
 }

tests/init/neg/final-fields.scala → tests/init/warn/final-fields.scala

@@ -29,10 +29,10 @@ class Test1 extends U {
 }
 
 class Test extends T {
- override final val f1 = /*super.f1*/ 1 + f2  // error
- override final val f2 = 2                    // error
- override final val f3 = {println(3); 3}      // error
- override val f4 = f3 + 1                     // error
+ override final val f1 = /*super.f1*/ 1 + f2  // warn
+ override final val f2 = 2                    // warn
+ override final val f3 = {println(3); 3}      // warn
+ override val f4 = f3 + 1                     // warn
 
  def g: 3 = { println("g"); 3 }
  final val x = g + 1

tests/init/neg/flow2.scala → tests/init/warn/flow2.scala

@@ -1,6 +1,6 @@
 class Foo {
   val len  = list.size
-  val list = List(4, 6)    // error
+  val list = List(4, 6)    // warn
 
   lazy val len2 = list2.size  // ok
   val list2 = List(4, 6)

tests/init/neg/function-loop.scala → tests/init/warn/function-loop.scala

@@ -2,5 +2,5 @@ class Foo {
   val f: Int => Foo = (x: Int) => if x > 0 then f(x) else this
   f(10).n
 
-  val n = 10   // error
+  val n = 10   // warn
 }

tests/init/neg/function1.scala → tests/init/warn/function1.scala

@@ -4,9 +4,9 @@ class Foo {
   val fun2: Int => Int = n => 1 + n + list.size
   fun2(5)
 
-  List(5, 9).map(n => 2 + n + list.size)         // error
+  List(5, 9).map(n => 2 + n + list.size)         // warn
 
-  final val list = List(1, 2, 3)                 // error
+  final val list = List(1, 2, 3)                 // warn
 
   List(5, 9).map(n => 3 + n + list.size)
 }

tests/init/neg/function10.scala → tests/init/warn/function10.scala

@@ -1,5 +1,5 @@
 class Base { self =>
-  (0 to 10).foreach { i =>             // error
+  (0 to 10).foreach { i =>             // warn
     println(a)
   }
 

tests/init/neg/function11.scala → tests/init/warn/function11.scala

@@ -1,7 +1,7 @@
 final class Capture {
   private var m: Boolean = false
 
-  (0 to 10).foreach { i =>      // error
+  (0 to 10).foreach { i =>      // warn
     f()
   }
 

tests/init/neg/function2.scala → tests/init/warn/function2.scala

@@ -2,5 +2,5 @@ final class Foo {
   def fun: Int => Int = n => n + x.size
   fun(5)
 
-  val x = "hello"   // error
+  val x = "hello"   // warn
 }

tests/init/neg/hybrid1.scala → tests/init/warn/hybrid1.scala

@@ -17,5 +17,5 @@ class Y {
 
   new C
 
-  val n = 10   // error
+  val n = 10   // warn
 }

tests/init/neg/hybrid2.scala → tests/init/warn/hybrid2.scala

@@ -15,5 +15,5 @@ class Y {
   val x = new X
   x.b.g
 
-  val n = 10     // error
+  val n = 10     // warn
 }

tests/init/neg/hybrid4.scala → tests/init/warn/hybrid4.scala

@@ -8,5 +8,5 @@ class Foo {
   }
 
   val bar: Bar = new Bar
-  val list = List(1, 2, 3)       // error
+  val list = List(1, 2, 3)       // warn
 }

tests/init/neg/hybrid5.scala → tests/init/warn/hybrid5.scala

@@ -15,5 +15,5 @@ class Foo {
     def g = new Foo.this.Inner
   }
 
-  val list = List(1, 2, 3)  // error
+  val list = List(1, 2, 3)  // warn
 }

tests/init/neg/hybrid6.scala → tests/init/warn/hybrid6.scala

@@ -11,5 +11,5 @@ class Foo {
     def g = list
   }
 
-  val list = List(1, 2, 3)    // error
+  val list = List(1, 2, 3)    // warn
 }

tests/init/neg/i10549b.scala → tests/init/warn/i10549b.scala

@@ -4,6 +4,6 @@ class Wrap {
   abstract class E[+T] { def foo: T }
   object E {
     final val A: E[Nothing] = new E { def foo = ref }
-    val ref = qux(A)      // error
+    val ref = qux(A)      // warn
   }
 }

tests/init/neg/i11572.scala → tests/init/warn/i11572.scala

@@ -5,7 +5,7 @@ class A {
   trait Bounded {
     type T >: Cov[Int] <: Cov[String]
   }
-  val t: Bounded = new Bounded {  // error
+  val t: Bounded = new Bounded {  // warn
     // Note: using this instead of t produces an error (as expected)
     override type T >: t.T <: t.T
   }

tests/init/neg/i12544.scala → tests/init/warn/i12544.scala

@@ -15,7 +15,7 @@ class Outer:
 
     class B() { def foo() = n + 1 }
     def g(b: B): Int = b.foo()
-    g(new B()) // error
+    g(new B()) // warn
     val n: Int = 10
 
 @main def main(): Unit = {

tests/init/neg/i15363.scala → tests/init/warn/i15363.scala

@@ -1,6 +1,6 @@
 class A:
   // should report one error here
-  val b = new B(this) // error
+  val b = new B(this) // warn
   val m = 10
   val n = 20