[do not merge] Add capture checking annotation to Scala 3 Standard Library

TODO.md

@@ -0,0 +1,103 @@
+- [x] library/src/scala/CanEqual.scala
+- [x] library/src/scala/CanThrow.scala
+- [x] library/src/scala/Conversion.scala
+- [x] library/src/scala/IArray.scala
+- [x] library/src/scala/NamedTuple.scala
+- [x] library/src/scala/PolyFunction.scala
+- [x] library/src/scala/Precise.scala
+- [x] library/src/scala/Pure.scala
+- [x] library/src/scala/Selectable.scala
+- [x] library/src/scala/Tuple.scala
+- [x] library/src/scala/annotation/MacroAnnotation.scala
+- [x] library/src/scala/annotation/RefiningAnnotation.scala
+- [x] library/src/scala/annotation/alpha.scala
+- [x] library/src/scala/annotation/capability.scala
+- [x] library/src/scala/annotation/constructorOnly.scala
+- [x] library/src/scala/annotation/experimental.scala
+- [x] library/src/scala/annotation/init.scala
+- [x] library/src/scala/annotation/internal/$into.scala
+- [x] library/src/scala/annotation/internal/Alias.scala
+- [x] library/src/scala/annotation/internal/AnnotationDefault.scala
+- [x] library/src/scala/annotation/internal/AssignedNonLocally.scala
+- [x] library/src/scala/annotation/internal/Body.scala
+- [x] library/src/scala/annotation/internal/CaptureChecked.scala
+- [x] library/src/scala/annotation/internal/Child.scala
+- [x] library/src/scala/annotation/internal/ContextResultCount.scala
+- [x] library/src/scala/annotation/internal/ErasedParam.scala
+- [x] library/src/scala/annotation/internal/InlineParam.scala
+- [x] library/src/scala/annotation/internal/MappedAlternative.scala
+- [x] library/src/scala/annotation/internal/ProvisionalSuperClass.scala
+- [x] library/src/scala/annotation/internal/Repeated.scala
+- [x] library/src/scala/annotation/internal/RuntimeChecked.scala
+- [x] library/src/scala/annotation/internal/SourceFile.scala
+- [x] library/src/scala/annotation/internal/WithPureFuns.scala
+- [x] library/src/scala/annotation/internal/WitnessNames.scala
+- [x] library/src/scala/annotation/internal/preview.scala
+- [x] library/src/scala/annotation/internal/reachCapability.scala
+- [x] library/src/scala/annotation/internal/readOnlyCapability.scala
+- [x] library/src/scala/annotation/internal/requiresCapability.scala
+- [x] library/src/scala/annotation/internal/sharable.scala
+- [x] library/src/scala/annotation/internal/unshared.scala
+- [x] library/src/scala/annotation/into.scala
+- [x] library/src/scala/annotation/publicInBinary.scala
+- [x] library/src/scala/annotation/retains.scala
+- [x] library/src/scala/annotation/retainsByName.scala
+- [x] library/src/scala/annotation/static.scala
+- [x] library/src/scala/annotation/targetName.scala
+- [x] library/src/scala/annotation/threadUnsafe.scala
+- [x] library/src/scala/annotation/transparentTrait.scala
+- [ ] library/src/scala/annotation/unchecked/uncheckedCapabilityLeaks.scala
+- [x] library/src/scala/annotation/unchecked/uncheckedCaptures.scala
+- [x] library/src/scala/annotation/unroll.scala
+- [x] library/src/scala/caps/package.scala
+- [x] library/src/scala/compiletime/ops/any.scala
+- [x] library/src/scala/compiletime/ops/boolean.scala
+- [x] library/src/scala/compiletime/ops/double.scala
+- [x] library/src/scala/compiletime/ops/float.scala
+- [x] library/src/scala/compiletime/ops/int.scala
+- [x] library/src/scala/compiletime/ops/long.scala
+- [x] library/src/scala/compiletime/ops/string.scala
+- [x] library/src/scala/compiletime/package.scala
+- [x] library/src/scala/compiletime/testing/Error.scala
+- [x] library/src/scala/compiletime/testing/ErrorKind.scala
+- [x] library/src/scala/compiletime/testing/package.scala
+- [x] library/src/scala/main.scala
+- [x] library/src/scala/quoted/Expr.scala
+- [x] library/src/scala/quoted/ExprMap.scala
+- [x] library/src/scala/quoted/Exprs.scala
+- [x] library/src/scala/quoted/FromExpr.scala
+- [x] library/src/scala/quoted/Quotes.scala
+- [x] library/src/scala/quoted/ToExpr.scala
+- [x] library/src/scala/quoted/Type.scala
+- [x] library/src/scala/quoted/Varargs.scala
+- [x] library/src/scala/quoted/runtime/Expr.scala
+- [x] library/src/scala/quoted/runtime/Patterns.scala
+- [x] library/src/scala/quoted/runtime/QuoteMatching.scala
+- [x] library/src/scala/quoted/runtime/QuoteUnpickler.scala
+- [x] library/src/scala/quoted/runtime/SplicedType.scala
+- [x] library/src/scala/quoted/runtime/StopMacroExpansion.scala
+- [x] library/src/scala/reflect/Enum.scala
+- [x] library/src/scala/reflect/Selectable.scala
+- [x] library/src/scala/reflect/TypeTest.scala
+- [x] library/src/scala/reflect/Typeable.scala
+- [x] library/src/scala/runtime/$throws.scala
+- [x] library/src/scala/runtime/Arrays.scala
+- [x] library/src/scala/runtime/EnumValue.scala
+- [x] library/src/scala/runtime/FunctionXXL.scala
+- [x] library/src/scala/runtime/LazyVals.scala
+- [x] library/src/scala/runtime/MatchCase.scala
+- [x] library/src/scala/runtime/Scala3RunTime.scala
+- [x] library/src/scala/runtime/TupleMirror.scala
+- [x] library/src/scala/runtime/TupleXXL.scala
+- [x] library/src/scala/runtime/TupledFunctions.scala
+- [x] library/src/scala/runtime/Tuples.scala
+- [x] library/src/scala/runtime/TypeBox.scala
+- [x] library/src/scala/runtime/coverage/Invoker.scala
+- [x] library/src/scala/runtime/stdLibPatches/Predef.scala
+- [x] library/src/scala/runtime/stdLibPatches/language.scala
+- [x] library/src/scala/util/CommandLineParser.scala
+- [x] library/src/scala/util/FromDigits.scala
+- [x] library/src/scala/util/NotGiven.scala
+- [x] library/src/scala/util/TupledFunction.scala
+- [x] library/src/scala/util/boundary.scala
+- [x] library/src/scala/util/control/NonLocalReturns.scala

compiler/src/dotty/tools/dotc/cc/Synthetics.scala

@@ -168,4 +168,4 @@ object Synthetics:
         transformCompareCaptures)
   end transform
 
-end Synthetics
+end Synthetics

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -1149,6 +1149,7 @@ class Definitions {
     "reactor.util.annotation.NonNullApi" ::
     "io.reactivex.annotations.NonNull" :: Nil)
 
+
   // convenient one-parameter method types
   def methOfAny(tp: Type): MethodType = MethodType(List(AnyType), tp)
   def methOfAnyVal(tp: Type): MethodType = MethodType(List(AnyValType), tp)

compiler/src/dotty/tools/dotc/core/StdNames.scala

@@ -530,6 +530,7 @@ object StdNames {
     val isEmpty: N              = "isEmpty"
     val isInstanceOf_ : N       = "isInstanceOf"
     val isInstanceOfPM: N       = "$isInstanceOf$"
+    val isSameLabelAs : N       = "isSameLabelAs"
     val java: N                 = "java"
     val key: N                  = "key"
     val label: N                = "label"

compiler/src/dotty/tools/dotc/transform/DropBreaks.scala

@@ -27,6 +27,8 @@ object DropBreaks:
     /** The number of other references to associated label */
     var otherRefs: Int = 0
 
+    override def toString() = s"LabelUsage($goto, $enclMeth, returnRefs = $returnRefs, otherRefs = $otherRefs)"
+
   private val LabelUsages = new Property.Key[Map[Symbol, LabelUsage]]
   private val ShadowedLabels = new Property.Key[Set[Symbol]]
 
@@ -63,13 +65,22 @@ class DropBreaks extends MiniPhase:
        */
       def unapply(expr: Tree)(using Context): Option[(Symbol, Symbol)] = stripTyped(expr) match
         case If(
-          Apply(Select(Select(ex: Ident, label), eq), (lbl @ Ident(local)) :: Nil),
+          Apply(Select(ex: Ident, isSameLabelAs), (lbl @ Ident(local)) :: Nil),
           Select(ex2: Ident, value),
           Apply(throww, (ex3: Ident) :: Nil))
-        if label == nme.label && eq == nme.eq && local == nme.local && value == nme.value
+        if isSameLabelAs == nme.isSameLabelAs && local == nme.local && value == nme.value
             && throww.symbol == defn.throwMethod
             && ex.symbol == ex2.symbol && ex.symbol == ex3.symbol =>
           Some((ex.symbol, lbl.symbol))
+        case If(
+          Apply(Select(ex: Ident, isSameLabelAs), (lbl @ Ident(local)) :: Nil),
+          Literal(_), // in the case where the value is constant folded
+          Apply(throww, (ex3: Ident) :: Nil))
+        if isSameLabelAs == nme.isSameLabelAs && local == nme.local
+            && throww.symbol == defn.throwMethod
+            && ex.symbol == ex3.symbol
+            && expr.tpe.isSingleton =>
+          Some((ex.symbol, lbl.symbol))
         case _ =>
           None
     end GuardedThrow

compiler/src/dotty/tools/dotc/transform/SyntheticMembers.scala

@@ -17,6 +17,8 @@ import util.Spans.Span
 import config.Printers.derive
 import NullOpsDecorator.*
 import scala.runtime.Statics
+import dotty.tools.dotc.config.Feature
+import dotty.tools.dotc.cc.CapturingType
 
 object SyntheticMembers {
 

compiler/test/dotty/tools/backend/jvm/LabelBytecodeTests.scala

@@ -21,7 +21,7 @@ class LabelBytecodeTests extends DottyBytecodeTest {
       """val local = boundary.Label[Long]()
         |try break(5L)(using local)
         |catch case ex: boundary.Break[Long] @unchecked =>
-        |  if ex.label eq local then ex.value
+        |  if ex.isSameLabelAs(local) then ex.value
         |  else throw ex
       """.stripMargin,
       "Long",

library/src/scala/CanEqual.scala

@@ -1,5 +1,7 @@
 package scala
 
+import language.experimental.captureChecking
+
 import annotation.implicitNotFound
 import scala.collection.{Seq, Set, Map}
 

library/src/scala/CanThrow.scala

@@ -2,6 +2,8 @@ package scala
 import language.experimental.erasedDefinitions
 import annotation.{implicitNotFound, experimental, capability}
 
+import language.experimental.captureChecking
+
 /** A capability class that allows to throw exception `E`. When used with the
  *  experimental.saferExceptions feature, a `throw Ex()` expression will require
  *  a given of class `CanThrow[Ex]` to be available.

library/src/scala/Conversion.scala

@@ -1,5 +1,7 @@
 package scala
 
+import language.experimental.captureChecking
+
 /** A class for implicit values that can serve as implicit conversions.
 *  The implicit resolution algorithm will act as if there existed
 *  the additional implicit definition:
@@ -23,12 +25,13 @@ package scala
 */
 @java.lang.FunctionalInterface
 abstract class Conversion[-T, +U] extends Function1[T, U]:
-  /** Convert value `x` of type `T` to type `U` */
-  def apply(x: T): U
+  self =>
+    /** Convert value `x` of type `T` to type `U` */
+    def apply(x: T): U
 
-  extension (x: T)
-    /** `x.convert` converts a value `x` of type `T` to type `U` */
-    def convert = this(x)
+    extension (x: T)
+      /** `x.convert` converts a value `x` of type `T` to type `U` */
+      def convert = this(x)
 
 object Conversion:
   import annotation.experimental
@@ -44,5 +47,4 @@ object Conversion:
   /** Unwrap an `into` */
   extension [T](x: into[T])
     @experimental def underlying: T = x
-
-end Conversion
+end Conversion