diff options
Diffstat (limited to 'src')
35 files changed, 288 insertions, 142 deletions
diff --git a/src/compiler/scala/reflect/macros/compiler/Errors.scala b/src/compiler/scala/reflect/macros/compiler/Errors.scala index 30ba082a81..9799428b40 100644 --- a/src/compiler/scala/reflect/macros/compiler/Errors.scala +++ b/src/compiler/scala/reflect/macros/compiler/Errors.scala @@ -33,7 +33,7 @@ trait Errors extends Traces { def MacroBundleNonStaticError() = implRefError("macro bundles must be static") - def MacroBundleWrongShapeError() = implRefError("macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member") + def MacroBundleWrongShapeError() = implRefError("macro bundles must be monomorphic traits extending either BlackboxMacro or WhiteboxMacro and not implementing their `val c: BlackboxContext/WhiteboxContext` member") // compatibility errors diff --git a/src/compiler/scala/reflect/macros/compiler/Resolvers.scala b/src/compiler/scala/reflect/macros/compiler/Resolvers.scala index 9c4db1990b..03d306f593 100644 --- a/src/compiler/scala/reflect/macros/compiler/Resolvers.scala +++ b/src/compiler/scala/reflect/macros/compiler/Resolvers.scala @@ -15,10 +15,6 @@ trait Resolvers { private val runDefinitions = currentRun.runDefinitions import runDefinitions.{Predef_???, _} - /** Determines the type of context implied by the macro def. - */ - val ctxTpe = MacroContextClass.tpe - /** Resolves a macro impl reference provided in the right-hand side of the given macro definition. * * Acceptable shapes of the right-hand side: @@ -44,14 +40,14 @@ trait Resolvers { } val untypedImplRef = typer.silent(_.typedTypeConstructor(maybeBundleRef)) match { - case SilentResultValue(result) if result.tpe.baseClasses.contains(MacroClass) => + case SilentResultValue(result) if mightBeMacroBundleType(result.tpe) => val bundleProto = result.tpe.typeSymbol val bundlePkg = bundleProto.enclosingPackageClass if (!isMacroBundleProtoType(bundleProto.tpe)) MacroBundleWrongShapeError() if (!bundleProto.owner.isStaticOwner) MacroBundleNonStaticError() // synthesize the bundle, i.e. given a static `trait Foo extends Macro { def expand = ... } ` - // create a top-level definition `class Foo$Bundle(val c: Context) extends Foo` in a package next to `Foo` + // create a top-level definition `class Foo$Bundle(val c: BlackboxContext/WhiteboxContext) extends Foo` in a package next to `Foo` val bundlePid = gen.mkUnattributedRef(bundlePkg) val bundlePrefix = if (bundlePkg == EmptyPackageClass) bundleProto.fullName('$') @@ -59,7 +55,8 @@ trait Resolvers { val bundleName = TypeName(bundlePrefix + tpnme.MACRO_BUNDLE_SUFFIX) val existingBundle = bundleProto.enclosingPackageClass.info.decl(bundleName) if (!currentRun.compiles(existingBundle)) { - def mkContextValDef(flags: Long) = ValDef(Modifiers(flags), nme.c, TypeTree(ctxTpe), EmptyTree) + val contextType = if (isBlackboxMacroBundleType(bundleProto.tpe)) BlackboxContextClass.tpe else WhiteboxContextClass.tpe + def mkContextValDef(flags: Long) = ValDef(Modifiers(flags), nme.c, TypeTree(contextType), EmptyTree) val contextField = mkContextValDef(PARAMACCESSOR) val contextParam = mkContextValDef(PARAM | PARAMACCESSOR) val bundleCtor = DefDef(Modifiers(), nme.CONSTRUCTOR, Nil, List(List(contextParam)), TypeTree(), Block(List(pendingSuperCall), Literal(Constant(())))) @@ -88,12 +85,13 @@ trait Resolvers { // lazy val (isImplBundle, macroImplOwner, macroImpl, macroImplTargs) = private lazy val dissectedMacroImplRef = macroImplRef match { - case MacroImplReference(isBundle, owner, meth, targs) => (isBundle, owner, meth, targs) + case MacroImplReference(isBundle, isBlackbox, owner, meth, targs) => (isBundle, isBlackbox, owner, meth, targs) case _ => MacroImplReferenceWrongShapeError() } lazy val isImplBundle = dissectedMacroImplRef._1 lazy val isImplMethod = !isImplBundle - lazy val macroImplOwner = dissectedMacroImplRef._2 - lazy val macroImpl = dissectedMacroImplRef._3 - lazy val targs = dissectedMacroImplRef._4 + lazy val isImplBlackbox = dissectedMacroImplRef._2 + lazy val macroImplOwner = dissectedMacroImplRef._3 + lazy val macroImpl = dissectedMacroImplRef._4 + lazy val targs = dissectedMacroImplRef._5 } diff --git a/src/compiler/scala/reflect/macros/compiler/Validators.scala b/src/compiler/scala/reflect/macros/compiler/Validators.scala index 088b108844..e77c129c51 100644 --- a/src/compiler/scala/reflect/macros/compiler/Validators.scala +++ b/src/compiler/scala/reflect/macros/compiler/Validators.scala @@ -49,8 +49,8 @@ trait Validators { map2(aparamss.flatten, rparamss.flatten)((aparam, rparam) => { if (aparam.name != rparam.name && !rparam.isSynthetic) MacroImplParamNameMismatchError(aparam, rparam) if (isRepeated(aparam) ^ isRepeated(rparam)) MacroImplVarargMismatchError(aparam, rparam) - val aparamtpe = aparam.tpe.dealias match { - case RefinedType(List(tpe), Scope(sym)) if tpe =:= ctxTpe && sym.allOverriddenSymbols.contains(MacroContextPrefixType) => tpe + val aparamtpe = aparam.tpe match { + case MacroContextType(tpe) => tpe case tpe => tpe } checkMacroImplParamTypeMismatch(atpeToRtpe(aparamtpe), rparam) @@ -93,20 +93,20 @@ trait Validators { * * For the following macro impl: * def fooBar[T: c.WeakTypeTag] - * (c: scala.reflect.macros.Context) + * (c: scala.reflect.macros.BlackboxContext) * (xs: c.Expr[List[T]]) * : c.Expr[T] = ... * * This function will return: - * (c: scala.reflect.macros.Context)(xs: c.Expr[List[T]])c.Expr[T] + * (c: scala.reflect.macros.BlackboxContext)(xs: c.Expr[List[T]])c.Expr[T] * * Note that type tag evidence parameters are not included into the result. * Type tag context bounds for macro impl tparams are optional. * Therefore compatibility checks ignore such parameters, and we don't need to bother about them here. * * This method cannot be reduced to just macroImpl.info, because macro implementations might - * come in different shapes. If the implementation is an apply method of a Macro-compatible object, - * then it won't have (c: Context) in its parameters, but will rather refer to Macro.c. + * come in different shapes. If the implementation is an apply method of a BlackboxMacro/WhiteboxMacro-compatible object, + * then it won't have (c: BlackboxContext/WhiteboxContext) in its parameters, but will rather refer to BlackboxMacro/WhiteboxMacro.c. * * @param macroImpl The macro implementation symbol */ @@ -123,7 +123,8 @@ trait Validators { * def foo[T](xs: List[T]): T = macro fooBar * * This function will return: - * (c: scala.reflect.macros.Context)(xs: c.Expr[List[T]])c.Expr[T] + * (c: scala.reflect.macros.BlackboxContext)(xs: c.Expr[List[T]])c.Expr[T] or + * (c: scala.reflect.macros.WhiteboxContext)(xs: c.Expr[List[T]])c.Expr[T] * * Note that type tag evidence parameters are not included into the result. * Type tag context bounds for macro impl tparams are optional. @@ -145,6 +146,7 @@ trait Validators { // had to move method's body to an object because of the recursive dependencies between sigma and param object SigGenerator { val cache = scala.collection.mutable.Map[Symbol, Symbol]() + val ctxTpe = if (isImplBlackbox) BlackboxContextClass.tpe else WhiteboxContextClass.tpe val ctxPrefix = if (isImplMethod) singleType(NoPrefix, makeParam(nme.macroContext, macroDdef.pos, ctxTpe, SYNTHETIC)) else singleType(ThisType(macroImpl.owner), macroImpl.owner.tpe.member(nme.c)) diff --git a/src/compiler/scala/reflect/macros/contexts/Context.scala b/src/compiler/scala/reflect/macros/contexts/Context.scala index 1355a839d9..7b79b52a18 100644 --- a/src/compiler/scala/reflect/macros/contexts/Context.scala +++ b/src/compiler/scala/reflect/macros/contexts/Context.scala @@ -3,7 +3,8 @@ package contexts import scala.tools.nsc.Global -abstract class Context extends scala.reflect.macros.Context +abstract class Context extends scala.reflect.macros.BlackboxContext + with scala.reflect.macros.WhiteboxContext with Aliases with Enclosures with Names diff --git a/src/compiler/scala/reflect/macros/runtime/MacroRuntimes.scala b/src/compiler/scala/reflect/macros/runtime/MacroRuntimes.scala index ffdbe11151..7de3341304 100644 --- a/src/compiler/scala/reflect/macros/runtime/MacroRuntimes.scala +++ b/src/compiler/scala/reflect/macros/runtime/MacroRuntimes.scala @@ -45,7 +45,7 @@ trait MacroRuntimes extends JavaReflectionRuntimes with ScalaReflectionRuntimes type MacroRuntime = MacroArgs => Any class MacroRuntimeResolver(val macroDef: Symbol) extends JavaReflectionResolvers with ScalaReflectionResolvers { - val binding = loadMacroImplBinding(macroDef) + val binding = loadMacroImplBinding(macroDef).get val isBundle = binding.isBundle val className = binding.className val methName = binding.methName diff --git a/src/compiler/scala/reflect/macros/util/Helpers.scala b/src/compiler/scala/reflect/macros/util/Helpers.scala index bb4f2055ad..ff03696524 100644 --- a/src/compiler/scala/reflect/macros/util/Helpers.scala +++ b/src/compiler/scala/reflect/macros/util/Helpers.scala @@ -27,13 +27,13 @@ trait Helpers { import runDefinitions._ val MacroContextUniverse = definitions.MacroContextUniverse - val treeInfo.MacroImplReference(isBundle, _, macroImpl, _) = macroImplRef + val treeInfo.MacroImplReference(isBundle, _, _, macroImpl, _) = macroImplRef val paramss = macroImpl.paramss val ContextParam = paramss match { - case Nil | _ :+ Nil => NoSymbol // no implicit parameters in the signature => nothing to do - case _ if isBundle => macroImpl.owner.tpe member nme.c - case (cparam :: _) :: _ if cparam.tpe <:< MacroContextClass.tpe => cparam - case _ => NoSymbol // no context parameter in the signature => nothing to do + case Nil | _ :+ Nil => NoSymbol // no implicit parameters in the signature => nothing to do + case _ if isBundle => macroImpl.owner.tpe member nme.c + case (cparam :: _) :: _ if isMacroContextType(cparam.tpe) => cparam + case _ => NoSymbol // no context parameter in the signature => nothing to do } def transformTag(param: Symbol): Symbol = param.tpe.dealias match { case TypeRef(SingleType(SingleType(_, ContextParam), MacroContextUniverse), WeakTypeTagClass, targ :: Nil) => transform(param, targ.typeSymbol) diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala index 92f95e282b..7ecc2be9be 100644 --- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala +++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala @@ -527,6 +527,9 @@ trait ContextErrors { def TooManyArgsPatternError(fun: Tree) = NormalTypeError(fun, "too many arguments for unapply pattern, maximum = "+definitions.MaxTupleArity) + def BlackboxExtractorExpansion(fun: Tree) = + NormalTypeError(fun, "extractor macros can only be whitebox") + def WrongShapeExtractorExpansion(fun: Tree) = NormalTypeError(fun, "extractor macros can only expand into extractor calls") diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala index b1a48f7478..c9dbdb93ff 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala @@ -1147,7 +1147,7 @@ trait Implicits { gen.mkAttributedThis(thisSym) case _ => // if `pre` is not a PDT, e.g. if someone wrote - // implicitly[scala.reflect.macros.Context#TypeTag[Int]] + // implicitly[scala.reflect.macros.BlackboxContext#TypeTag[Int]] // then we need to fail, because we don't know the prefix to use during type reification // upd. we also need to fail silently, because this is a very common situation // e.g. quite often we're searching for BaseUniverse#TypeTag, e.g. for a type tag in any universe diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala index 02fb70f3e5..f1b9bd4833 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala @@ -29,7 +29,7 @@ import Fingerprint._ * Then fooBar needs to point to a static method of the following form: * * def fooBar[T: c.WeakTypeTag] // type tag annotation is optional - * (c: scala.reflect.macros.Context) + * (c: scala.reflect.macros.BlackboxContext) * (xs: c.Expr[List[T]]) * : c.Expr[T] = { * ... @@ -67,7 +67,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { * * This solution is very simple, but unfortunately it's also lacking. If we use it, then * signatures of macro defs become transitively dependent on scala-reflect.jar - * (because they refer to macro impls, and macro impls refer to scala.reflect.macros.Context defined in scala-reflect.jar). + * (because they refer to macro impls, and macro impls refer to scala.reflect.macros.BlackboxContext/WhiteboxContext defined in scala-reflect.jar). * More details can be found in comments to https://issues.scala-lang.org/browse/SI-5940. * * Therefore we have to avoid putting macro impls into binding pickles and come up with our own serialization format. @@ -81,40 +81,42 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { * and various accounting information necessary when composing an argument list for the reflective invocation. */ case class MacroImplBinding( - // Is this macro impl a bundle (a trait extending Macro) or a vanilla def? - val isBundle: Boolean, - // Java class name of the class that contains the macro implementation - // is used to load the corresponding object with Java reflection - className: String, - // method name of the macro implementation - // `className` and `methName` are all we need to reflectively invoke a macro implementation - // because macro implementations cannot be overloaded - methName: String, - // flattens the macro impl's parameter lists having symbols replaced with their fingerprints - // currently fingerprints are calculated solely from types of the symbols: - // * c.Expr[T] => LiftedTyped - // * c.Tree => LiftedUntyped - // * c.WeakTypeTag[T] => Tagged(index of the type parameter corresponding to that type tag) - // * everything else (e.g. scala.reflect.macros.Context) => Other - // f.ex. for: def impl[T: WeakTypeTag, U, V: WeakTypeTag](c: Context)(x: c.Expr[T], y: c.Tree): (U, V) = ??? - // `signature` will be equal to List(List(Other), List(LiftedTyped, LiftedUntyped), List(Tagged(0), Tagged(2))) - signature: List[List[Fingerprint]], - // type arguments part of a macro impl ref (the right-hand side of a macro definition) - // these trees don't refer to a macro impl, so we can pickle them as is - targs: List[Tree]) { - + // Is this macro impl a bundle (a trait extending BlackboxMacro or WhiteboxMacro) or a vanilla def? + val isBundle: Boolean, + // Is this macro impl blackbox (i.e. having BlackboxContext in its signature)? + val isBlackbox: Boolean, + // Java class name of the class that contains the macro implementation + // is used to load the corresponding object with Java reflection + className: String, + // method name of the macro implementation + // `className` and `methName` are all we need to reflectively invoke a macro implementation + // because macro implementations cannot be overloaded + methName: String, + // flattens the macro impl's parameter lists having symbols replaced with their fingerprints + // currently fingerprints are calculated solely from types of the symbols: + // * c.Expr[T] => LiftedTyped + // * c.Tree => LiftedUntyped + // * c.WeakTypeTag[T] => Tagged(index of the type parameter corresponding to that type tag) + // * everything else (e.g. scala.reflect.macros.BlackboxContext/WhiteboxContext) => Other + // f.ex. for: def impl[T: WeakTypeTag, U, V: WeakTypeTag](c: BlackboxContext)(x: c.Expr[T], y: c.Tree): (U, V) = ??? + // `signature` will be equal to List(List(Other), List(LiftedTyped, LiftedUntyped), List(Tagged(0), Tagged(2))) + signature: List[List[Fingerprint]], + // type arguments part of a macro impl ref (the right-hand side of a macro definition) + // these trees don't refer to a macro impl, so we can pickle them as is + targs: List[Tree]) { // Was this binding derived from a `def ... = macro ???` definition? def is_??? = { val Predef_??? = currentRun.runDefinitions.Predef_??? className == Predef_???.owner.javaClassName && methName == Predef_???.name.encoded } + def isWhitebox = !isBlackbox } /** Macro def -> macro impl bindings are serialized into a `macroImpl` annotation * with synthetic content that carries the payload described in `MacroImplBinding`. * * For example, for a pair of macro definition and macro implementation: - * def impl(c: scala.reflect.macros.Context): c.Expr[Unit] = ??? + * def impl(c: scala.reflect.macros.BlackboxContext): c.Expr[Unit] = ??? * def foo: Unit = macro impl * * We will have the following annotation added on the macro definition `foo`: @@ -122,13 +124,14 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { * @scala.reflect.macros.internal.macroImpl( * `macro`( * "isBundle" = false, + * "isBlackbox" = true, * "signature" = List(Other), * "methodName" = "impl", * "versionFormat" = <current version format>, * "className" = "Macros$")) */ object MacroImplBinding { - val versionFormat = 5.0 + val versionFormat = 6.0 def pickleAtom(obj: Any): Tree = obj match { @@ -151,7 +154,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { def pickle(macroImplRef: Tree): Tree = { val runDefinitions = currentRun.runDefinitions import runDefinitions._ - val MacroImplReference(isBundle, owner, macroImpl, targs) = macroImplRef + val MacroImplReference(isBundle, isBlackbox, owner, macroImpl, targs) = macroImplRef // todo. refactor when fixing SI-5498 def className: String = { @@ -182,6 +185,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { val payload = List[(String, Any)]( "versionFormat" -> versionFormat, "isBundle" -> isBundle, + "isBlackbox" -> isBlackbox, "className" -> className, "methodName" -> macroImpl.name.toString, "signature" -> signature @@ -237,10 +241,11 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { if (versionFormat != pickleVersionFormat) fail(s"expected version format $versionFormat, actual $pickleVersionFormat") val isBundle = unpickle("isBundle", classOf[Boolean]) + val isBlackbox = unpickle("isBlackbox", classOf[Boolean]) val className = unpickle("className", classOf[String]) val methodName = unpickle("methodName", classOf[String]) val signature = unpickle("signature", classOf[List[List[Fingerprint]]]) - MacroImplBinding(isBundle, className, methodName, signature, targs) + MacroImplBinding(isBundle, isBlackbox, className, methodName, signature, targs) } } @@ -249,14 +254,17 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { macroDef withAnnotation AnnotationInfo(MacroImplAnnotation.tpe, List(pickle), Nil) } - def loadMacroImplBinding(macroDef: Symbol): MacroImplBinding = { - val Some(AnnotationInfo(_, List(pickle), _)) = macroDef.getAnnotation(MacroImplAnnotation) - MacroImplBinding.unpickle(pickle) - } + def loadMacroImplBinding(macroDef: Symbol): Option[MacroImplBinding] = + macroDef.getAnnotation(MacroImplAnnotation) collect { + case AnnotationInfo(_, List(pickle), _) => MacroImplBinding.unpickle(pickle) + } + + def isBlackbox(expandee: Tree): Boolean = isBlackbox(dissectApplied(expandee).core.symbol) + def isBlackbox(macroDef: Symbol): Boolean = loadMacroImplBinding(macroDef).map(_.isBlackbox).getOrElse(false) def computeMacroDefTypeFromMacroImplRef(macroDdef: DefDef, macroImplRef: Tree): Type = { macroImplRef match { - case MacroImplReference(_, _, macroImpl, targs) => + case MacroImplReference(_, _, _, macroImpl, targs) => // Step I. Transform c.Expr[T] to T and everything else to Any var runtimeType = decreaseMetalevel(macroImpl.info.finalResultType) @@ -450,7 +458,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { (trees :+ tags).flatten } - val binding = loadMacroImplBinding(macroDef) + val binding = loadMacroImplBinding(macroDef).get if (binding.is_???) Nil else calculateMacroArgs(binding) } @@ -459,7 +467,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers { } /** Keeps track of macros in-flight. - * See more informations in comments to `openMacros` in `scala.reflect.macros.Context`. + * See more informations in comments to `openMacros` in `scala.reflect.macros.WhiteboxContext`. */ private var _openMacros = List[MacroContext]() def openMacros = _openMacros diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index a9bb81c691..fa704adde2 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -1111,7 +1111,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper } if (tree.isType) adaptType() - else if (mode.typingExprNotFun && treeInfo.isMacroApplication(tree)) + else if (mode.typingExprNotFun && treeInfo.isMacroApplication(tree) && !isMacroExpansionSuppressed(tree)) macroExpandApply(this, tree, mode, pt) else if (mode.typingConstructorPattern) typedConstructorPattern(tree, pt) diff --git a/src/compiler/scala/tools/reflect/StdTags.scala b/src/compiler/scala/tools/reflect/StdTags.scala index 6c1821f8aa..5c53c81e8b 100644 --- a/src/compiler/scala/tools/reflect/StdTags.scala +++ b/src/compiler/scala/tools/reflect/StdTags.scala @@ -49,7 +49,7 @@ object StdRuntimeTags extends StdTags { } abstract class StdContextTags extends StdTags { - val tc: scala.reflect.macros.Context + val tc: scala.reflect.macros.contexts.Context val u: tc.universe.type = tc.universe val m = tc.mirror } diff --git a/src/partest-extras/scala/tools/partest/Util.scala b/src/partest-extras/scala/tools/partest/Util.scala index 114658b0cd..8214396291 100644 --- a/src/partest-extras/scala/tools/partest/Util.scala +++ b/src/partest-extras/scala/tools/partest/Util.scala @@ -16,8 +16,8 @@ object Util { */ def trace[A](a: A) = macro traceImpl[A] - import scala.reflect.macros.Context - def traceImpl[A: c.WeakTypeTag](c: Context)(a: c.Expr[A]): c.Expr[A] = { + import scala.reflect.macros.BlackboxContext + def traceImpl[A: c.WeakTypeTag](c: BlackboxContext)(a: c.Expr[A]): c.Expr[A] = { import c.universe._ import definitions._ diff --git a/src/reflect/scala/reflect/api/Exprs.scala b/src/reflect/scala/reflect/api/Exprs.scala index 5b6ff2325c..50c8aa8779 100644 --- a/src/reflect/scala/reflect/api/Exprs.scala +++ b/src/reflect/scala/reflect/api/Exprs.scala @@ -106,7 +106,7 @@ trait Exprs { self: Universe => * * The corresponding macro implementation should have the following signature (note how the return type denotes path-dependency on x): * {{{ - * object Impls { def foo_impl(c: Context)(x: c.Expr[X]): c.Expr[x.value.T] = ... } + * object Impls { def foo_impl(c: BlackboxContext)(x: c.Expr[X]): c.Expr[x.value.T] = ... } * }}} */ @compileTimeOnly("cannot use value except for signatures of macro implementations") diff --git a/src/reflect/scala/reflect/api/Importers.scala b/src/reflect/scala/reflect/api/Importers.scala index 4182b7d0ba..e239b86452 100644 --- a/src/reflect/scala/reflect/api/Importers.scala +++ b/src/reflect/scala/reflect/api/Importers.scala @@ -34,7 +34,7 @@ package api * {{{ * def staticEval[T](x: T) = macro staticEval[T] * - * def staticEval[T](c: scala.reflect.macros.Context)(x: c.Expr[T]) = { + * def staticEval[T](c: scala.reflect.macros.BlackboxContext)(x: c.Expr[T]) = { * // creates a runtime reflection universe to host runtime compilation * import scala.reflect.runtime.{universe => ru} * val mirror = ru.runtimeMirror(c.libraryClassLoader) diff --git a/src/reflect/scala/reflect/api/Mirrors.scala b/src/reflect/scala/reflect/api/Mirrors.scala index ec128e31a3..a4cd531053 100644 --- a/src/reflect/scala/reflect/api/Mirrors.scala +++ b/src/reflect/scala/reflect/api/Mirrors.scala @@ -29,19 +29,19 @@ package api * Compile-time `Mirror`s make use of only classloader `Mirror`s to load `Symbol`s * by name. * - * The entry point to classloader `Mirror`s is via [[scala.reflect.macros.Context#mirror]]. + * The entry point to classloader `Mirror`s is via [[scala.reflect.macros.BlackboxContext#mirror]] or [[scala.reflect.macros.WhiteboxContext#mirror]]. * Typical methods which use classloader `Mirror`s include [[scala.reflect.api.Mirror#staticClass]], * [[scala.reflect.api.Mirror#staticModule]], and [[scala.reflect.api.Mirror#staticPackage]]. For * example: * {{{ - * import scala.reflect.macros.Context + * import scala.reflect.macros.BlackboxContext * * case class Location(filename: String, line: Int, column: Int) * * object Macros { * def currentLocation: Location = macro impl * - * def impl(c: Context): c.Expr[Location] = { + * def impl(c: BlackboxContext): c.Expr[Location] = { * import c.universe._ * val pos = c.macroApplication.pos * val clsLocation = c.mirror.staticModule("Location") // get symbol of "Location" object diff --git a/src/reflect/scala/reflect/api/Universe.scala b/src/reflect/scala/reflect/api/Universe.scala index 77b4827eab..534f69a23e 100644 --- a/src/reflect/scala/reflect/api/Universe.scala +++ b/src/reflect/scala/reflect/api/Universe.scala @@ -41,10 +41,11 @@ package api * res1: reflect.runtime.universe.Type = scala.Either[String,Int] * }}} * - * To obtain a `Universe` for use within a Scala macro, use [[scala.reflect.macros.Context#universe]]. For example: + * To obtain a `Universe` for use within a Scala macro, use [[scala.reflect.macros.BlackboxContext#universe]]. + * or [[scala.reflect.macros.WhiteboxContext#universe]]. For example: * {{{ * def printf(format: String, params: Any*): Unit = macro impl - * def impl(c: Context)(format: c.Expr[String], params: c.Expr[Any]*): c.Expr[Unit] = { + * def impl(c: BlackboxContext)(format: c.Expr[String], params: c.Expr[Any]*): c.Expr[Unit] = { * import c.universe._ * ... * } diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala index 7cb051c63d..563f23cb3b 100644 --- a/src/reflect/scala/reflect/internal/Definitions.scala +++ b/src/reflect/scala/reflect/internal/Definitions.scala @@ -495,15 +495,18 @@ trait Definitions extends api.StandardDefinitions { lazy val TreeCreatorClass = getClassIfDefined("scala.reflect.api.TreeCreator") // defined in scala-reflect.jar, so we need to be careful lazy val LiftableClass = getClassIfDefined("scala.reflect.api.Liftable") // defined in scala-reflect.jar, so we need to be careful - lazy val MacroClass = getClassIfDefined("scala.reflect.macros.Macro") // defined in scala-reflect.jar, so we need to be careful - def MacroContextValue = MacroClass.map(sym => getMemberValue(sym, nme.c)) - lazy val MacroContextClass = getClassIfDefined("scala.reflect.macros.Context") // defined in scala-reflect.jar, so we need to be careful - def MacroContextPrefix = MacroContextClass.map(sym => getMemberMethod(sym, nme.prefix)) - def MacroContextPrefixType = MacroContextClass.map(sym => getTypeMember(sym, tpnme.PrefixType)) - def MacroContextUniverse = MacroContextClass.map(sym => getMemberMethod(sym, nme.universe)) - def MacroContextExprClass = MacroContextClass.map(sym => getTypeMember(sym, tpnme.Expr)) - def MacroContextWeakTypeTagClass = MacroContextClass.map(sym => getTypeMember(sym, tpnme.WeakTypeTag)) - def MacroContextTreeType = MacroContextClass.map(sym => getTypeMember(sym, tpnme.Tree)) + lazy val BlackboxMacroClass = getClassIfDefined("scala.reflect.macros.BlackboxMacro") // defined in scala-reflect.jar, so we need to be careful + def BlackboxMacroContextValue = BlackboxMacroClass.map(sym => getMemberValue(sym, nme.c)) + lazy val WhiteboxMacroClass = getClassIfDefined("scala.reflect.macros.WhiteboxMacro") // defined in scala-reflect.jar, so we need to be careful + def WhiteboxMacroContextValue = WhiteboxMacroClass.map(sym => getMemberValue(sym, nme.c)) + lazy val BlackboxContextClass = getClassIfDefined("scala.reflect.macros.BlackboxContext") // defined in scala-reflect.jar, so we need to be careful + lazy val WhiteboxContextClass = getClassIfDefined("scala.reflect.macros.WhiteboxContext") // defined in scala-reflect.jar, so we need to be careful + def MacroContextPrefix = BlackboxContextClass.map(sym => getMemberMethod(sym, nme.prefix)) + def MacroContextPrefixType = BlackboxContextClass.map(sym => getTypeMember(sym, tpnme.PrefixType)) + def MacroContextUniverse = BlackboxContextClass.map(sym => getMemberMethod(sym, nme.universe)) + def MacroContextExprClass = BlackboxContextClass.map(sym => getTypeMember(sym, tpnme.Expr)) + def MacroContextWeakTypeTagClass = BlackboxContextClass.map(sym => getTypeMember(sym, tpnme.WeakTypeTag)) + def MacroContextTreeType = BlackboxContextClass.map(sym => getTypeMember(sym, tpnme.Tree)) lazy val MacroImplAnnotation = requiredClass[scala.reflect.macros.internal.macroImpl] lazy val StringContextClass = requiredClass[scala.StringContext] @@ -593,18 +596,47 @@ trait Definitions extends api.StandardDefinitions { def unspecializedTypeArgs(tp: Type): List[Type] = (tp baseType unspecializedSymbol(tp.typeSymbolDirect)).typeArgs + object MacroContextType { + def unapply(tp: Type) = { + def isOneOfContextTypes(tp: Type) = + tp =:= BlackboxContextClass.tpe || tp =:= WhiteboxContextClass.tpe + def isPrefix(sym: Symbol) = + sym.allOverriddenSymbols.contains(MacroContextPrefixType) + + tp.dealias match { + case RefinedType(List(tp), Scope(sym)) if isOneOfContextTypes(tp) && isPrefix(sym) => Some(tp) + case tp if isOneOfContextTypes(tp) => Some(tp) + case _ => None + } + } + } + + def isMacroContextType(tp: Type) = MacroContextType.unapply(tp).isDefined + + def isWhiteboxContextType(tp: Type) = + isMacroContextType(tp) && (tp <:< WhiteboxContextClass.tpe) + + def mightBeMacroBundleType(tp: Type) = + tp.baseClasses.contains(WhiteboxMacroClass) || + tp.baseClasses.contains(BlackboxMacroClass) + def isMacroBundleType(tp: Type) = tp.baseClasses match { case _ :: proto :: _ if isMacroBundleProtoType(proto.tpe) => true case _ => false } + def isBlackboxMacroBundleType(tp: Type) = + isMacroBundleType(tp) && (tp <:< BlackboxMacroClass.tpe) && !(tp <:< WhiteboxMacroClass.tpe) + def isMacroBundleProtoType(tp: Type) = { val sym = tp.typeSymbol val isNonTrivial = tp != ErrorType && tp != NothingTpe && tp != NullTpe - val isMacroCompatible = MacroClass != NoSymbol && tp.baseClasses.contains(MacroClass) - val isBundlePrototype = sym != MacroClass && sym.isTrait && { + def subclasses(sym: Symbol) = sym != NoSymbol && tp.baseClasses.contains(sym) + val isMacroCompatible = subclasses(BlackboxMacroClass) ^ subclasses(WhiteboxMacroClass) + val isBundlePrototype = sym != BlackboxMacroClass && sym != WhiteboxMacroClass && sym.isTrait && { val c = sym.info.member(nme.c) - val cIsOk = c.overrideChain.contains(MacroContextValue) && c.isDeferred + def overrides(sym: Symbol) = c.overrideChain.contains(sym) + val cIsOk = (overrides(BlackboxMacroContextValue) || overrides(WhiteboxMacroContextValue)) && c.isDeferred cIsOk && sym.isMonomorphicType } isNonTrivial && isMacroCompatible && isBundlePrototype diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala index 025965ad47..8982fd4246 100644 --- a/src/reflect/scala/reflect/internal/TreeInfo.scala +++ b/src/reflect/scala/reflect/internal/TreeInfo.scala @@ -18,7 +18,7 @@ abstract class TreeInfo { val global: SymbolTable import global._ - import definitions.{ isTupleSymbol, isVarArgsList, isCastSymbol, ThrowableClass, TupleClass, MacroContextClass, MacroContextPrefixType, uncheckedStableClass } + import definitions.{ isTupleSymbol, isVarArgsList, isCastSymbol, ThrowableClass, TupleClass, uncheckedStableClass, isBlackboxMacroBundleType, isWhiteboxContextType } /* Does not seem to be used. Not sure what it does anyway. def isOwnerDefinition(tree: Tree): Boolean = tree match { @@ -822,13 +822,19 @@ abstract class TreeInfo { case ref: RefTree => { val qual = ref.qualifier val isBundle = definitions.isMacroBundleType(qual.tpe) + val isBlackbox = + if (isBundle) isBlackboxMacroBundleType(qual.tpe) + else ref.symbol.paramss match { + case (c :: Nil) :: _ if isWhiteboxContextType(c.info) => false + case _ => true + } val owner = if (isBundle) qual.tpe.typeSymbol else { - val sym = if (qual.hasSymbolField) qual.symbol else NoSymbol - if (sym.isModule) sym.moduleClass else sym + val qualSym = if (qual.hasSymbolField) qual.symbol else NoSymbol + if (qualSym.isModule) qualSym.moduleClass else qualSym } - Some((isBundle, owner, ref.symbol, dissectApplied(tree).targs)) + Some((isBundle, isBlackbox, owner, ref.symbol, dissectApplied(tree).targs)) } case _ => None } diff --git a/src/reflect/scala/reflect/macros/Aliases.scala b/src/reflect/scala/reflect/macros/Aliases.scala index 9e05f343e6..ca599dbd49 100644 --- a/src/reflect/scala/reflect/macros/Aliases.scala +++ b/src/reflect/scala/reflect/macros/Aliases.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that defines shorthands for the + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that defines shorthands for the * most frequently used types and functions of the underlying compiler universe. */ trait Aliases { - self: Context => + self: BlackboxContext => /** The type of symbols representing declarations. */ type Symbol = universe.Symbol diff --git a/src/reflect/scala/reflect/macros/Context.scala b/src/reflect/scala/reflect/macros/BlackboxContext.scala index b0c816f4ad..2c77289866 100644 --- a/src/reflect/scala/reflect/macros/Context.scala +++ b/src/reflect/scala/reflect/macros/BlackboxContext.scala @@ -2,14 +2,10 @@ package scala package reflect package macros -// todo. introduce context hierarchy -// the most lightweight context should just expose the stuff from the SIP -// the full context should include all traits from scala.reflect.macros (and probably reside in scala-compiler.jar) - /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * The Scala macros context. + * The blackbox Scala macros context. * * See [[scala.reflect.macros.package the overview page]] for a description of how macros work. This documentation * entry provides information on the API available to macro writers. @@ -27,17 +23,25 @@ package macros * Other than that, macro contexts provide facilities for typechecking, exploring the compiler's symbol table and * enclosing trees and compilation units, evaluating trees, logging warnings/errors and much more. * Refer to the documentation of top-level traits in this package to learn the details. + * + * If a macro def refers to a macro impl that uses `BlackboxContext`, then this macro def becomes a blackbox macro, + * which means that its expansion will be upcast to its return type, enforcing faithfullness of that macro to its + * type signature. Whitebox macros, i.e. the ones defined with `WhiteboxContext`, aren't bound by this restriction, + * which enables a number of important use cases, but they are also going to enjoy less support than blackbox macros, + * so choose wisely. See the [[http://docs.scala-lang.org/overviews/macros.html Macros Guide]] for more information. + * + * @see `scala.reflect.macros.WhiteboxContext` */ -trait Context extends Aliases - with Enclosures - with Names - with Reifiers - with FrontEnds - with Infrastructure - with Typers - with Parsers - with Evals - with ExprUtils { +trait BlackboxContext extends Aliases + with Enclosures + with Names + with Reifiers + with FrontEnds + with Infrastructure + with Typers + with Parsers + with Evals + with ExprUtils { /** The compile-time universe. */ val universe: Universe @@ -59,7 +63,7 @@ trait Context extends Aliases * scala> class Coll[T] { * | def filter(p: T => Boolean): Coll[T] = macro M.filter[T] * | }; object M { - * | def filter[T](c: Context { type PrefixType = Coll[T] }) + * | def filter[T](c: BlackboxContext { type PrefixType = Coll[T] }) * | (p: c.Expr[T => Boolean]): c.Expr[Coll[T]] = * | { * | println(c.prefix.tree) diff --git a/src/reflect/scala/reflect/macros/Macro.scala b/src/reflect/scala/reflect/macros/BlackboxMacro.scala index 44bedf483d..df142e9238 100644 --- a/src/reflect/scala/reflect/macros/Macro.scala +++ b/src/reflect/scala/reflect/macros/BlackboxMacro.scala @@ -6,15 +6,15 @@ package macros * * Traditionally macro implementations are defined as methods, * but this trait provides an alternative way of encoding macro impls as - * bundles, traits which extend `scala.reflect.macros.Macro`. + * bundles, traits which extend `scala.reflect.macros.BlackboxMacro` or`scala.reflect.macros.WhiteboxMacro` . * * Instead of: * - * def impl[T: c.WeakTypeTag](c: Context)(x: c.Expr[Int]) = ... + * def impl[T: c.WeakTypeTag](c: BlackboxContext)(x: c.Expr[Int]) = ... * * One can write: * - * trait Impl extends Macro { + * trait Impl extends BlackboxMacro { * def apply[T: c.WeakTypeTag](x: c.Expr[Int]) = ... * } * @@ -24,16 +24,13 @@ package macros * are complex and need to be modularized. State of the art technique of addressing this need is quite heavyweight: * http://docs.scala-lang.org/overviews/macros/overview.html#writing_bigger_macros. * - * However utility of this approach to writing macros isn't limited to just convenience. - * When a macro implementation becomes not just a function, but a full-fledged module, - * it can define callbacks that will be called by the compiler upon interesting events. - * In subsequent commits I will add support for programmable type inference + * @see `scala.reflect.macros.WhiteboxMacro` */ -trait Macro { +trait BlackboxMacro { /** The context to be used by the macro implementation. * * Vanilla macro implementations have to carry it in their signatures, however when a macro is a full-fledged module, * it can define the context next to the implementation, makes implementation signature more lightweight. */ - val c: Context + val c: BlackboxContext } diff --git a/src/reflect/scala/reflect/macros/Enclosures.scala b/src/reflect/scala/reflect/macros/Enclosures.scala index d6ba5f39cd..c3d019ccf3 100644 --- a/src/reflect/scala/reflect/macros/Enclosures.scala +++ b/src/reflect/scala/reflect/macros/Enclosures.scala @@ -7,13 +7,13 @@ import scala.language.existentials // SI-6541 /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that exposes + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that exposes * enclosing trees (method, class, compilation unit and currently compiled application), * the enclosing position of the macro expansion, as well as macros and implicits * that are currently in-flight. */ trait Enclosures { - self: Context => + self: BlackboxContext => /** The tree that undergoes macro expansion. * Can be useful to get an offset or a range position of the entire tree being processed. @@ -43,7 +43,7 @@ trait Enclosures { * Unlike `openMacros`, this is a val, which means that it gets initialized when the context is created * and always stays the same regardless of whatever happens during macro expansion. */ - def enclosingMacros: List[Context] + def enclosingMacros: List[BlackboxContext] /** Information about one of the currently considered implicit candidates. * Candidates are used in plural form, because implicit parameters may themselves have implicit parameters, diff --git a/src/reflect/scala/reflect/macros/Evals.scala b/src/reflect/scala/reflect/macros/Evals.scala index 70b2ab58d4..eb37e83cad 100644 --- a/src/reflect/scala/reflect/macros/Evals.scala +++ b/src/reflect/scala/reflect/macros/Evals.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that provides + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that provides * a facility to evaluate trees. */ trait Evals { - self: Context => + self: BlackboxContext => /** Takes a typed wrapper for a tree of type `T` and evaluates it to a value of type `T`. * @@ -21,12 +21,12 @@ trait Evals { * mutates the tree in place, therefore the conventional approach is to `duplicate` the tree first. * * {{{ - * scala> def impl(c: Context)(x: c.Expr[String]) = { + * scala> def impl(c: BlackboxContext)(x: c.Expr[String]) = { * | val x1 = c.Expr[String](c.resetAllAttrs(x.tree.duplicate)) * | println(s"compile-time value is: \${c.eval(x1)}") * | x * | } - * impl: (c: Context)(x: c.Expr[String])c.Expr[String] + * impl: (c: BlackboxContext)(x: c.Expr[String])c.Expr[String] * * scala> def test(x: String) = macro impl * test: (x: String)String diff --git a/src/reflect/scala/reflect/macros/ExprUtils.scala b/src/reflect/scala/reflect/macros/ExprUtils.scala index 76a8392b9c..58b61e446a 100644 --- a/src/reflect/scala/reflect/macros/ExprUtils.scala +++ b/src/reflect/scala/reflect/macros/ExprUtils.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that defines shorthands for the + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that defines shorthands for the * most common `Expr`-creating functions. */ trait ExprUtils { - self: Context => + self: BlackboxContext => /** Shorthand for `Literal(Constant(null))` in the underlying `universe`. */ @deprecated("Use quasiquotes instead", "2.11.0") diff --git a/src/reflect/scala/reflect/macros/FrontEnds.scala b/src/reflect/scala/reflect/macros/FrontEnds.scala index 6abd8c335b..3a910d89ad 100644 --- a/src/reflect/scala/reflect/macros/FrontEnds.scala +++ b/src/reflect/scala/reflect/macros/FrontEnds.scala @@ -5,12 +5,12 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that * provides facilities to communicate with the compiler's front end * (emit warnings, errors and other sorts of messages). */ trait FrontEnds { - self: Context => + self: BlackboxContext => /** For sending a message which should not be labeled as a warning/error, * but also shouldn't require -verbose to be visible. diff --git a/src/reflect/scala/reflect/macros/Infrastructure.scala b/src/reflect/scala/reflect/macros/Infrastructure.scala index eb63fb7b7f..b6585f94d2 100644 --- a/src/reflect/scala/reflect/macros/Infrastructure.scala +++ b/src/reflect/scala/reflect/macros/Infrastructure.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that * provides facilities to communicate with the compiler's infrastructure. */ trait Infrastructure { - self: Context => + self: BlackboxContext => /** Exposes macro-specific settings as a list of strings. * These settings are passed to the compiler via the "-Xmacro-settings:setting1,setting2...,settingN" command-line option. diff --git a/src/reflect/scala/reflect/macros/Names.scala b/src/reflect/scala/reflect/macros/Names.scala index 8773175561..6bd3e1a199 100644 --- a/src/reflect/scala/reflect/macros/Names.scala +++ b/src/reflect/scala/reflect/macros/Names.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that * provides functions that generate unique names. */ trait Names { - self: Context => + self: BlackboxContext => /** Creates a unique string. */ @deprecated("Use freshName instead", "2.11.0") diff --git a/src/reflect/scala/reflect/macros/Parsers.scala b/src/reflect/scala/reflect/macros/Parsers.scala index 4232b05f8c..cbfb30f022 100644 --- a/src/reflect/scala/reflect/macros/Parsers.scala +++ b/src/reflect/scala/reflect/macros/Parsers.scala @@ -5,12 +5,12 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that * exposes functions to parse strings with Scala code into trees. */ @deprecated("Use quasiquotes instead", "2.11.0") trait Parsers { - self: Context => + self: BlackboxContext => /** Parses a string with a Scala expression into an abstract syntax tree. * Only works for expressions, i.e. parsing a package declaration will fail. diff --git a/src/reflect/scala/reflect/macros/Reifiers.scala b/src/reflect/scala/reflect/macros/Reifiers.scala index 6ebd2db730..67d10dc10a 100644 --- a/src/reflect/scala/reflect/macros/Reifiers.scala +++ b/src/reflect/scala/reflect/macros/Reifiers.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that * exposes functions to save reflection artifacts for runtime. */ trait Reifiers { - self: Context => + self: BlackboxContext => /** Given a tree, generate a tree that when compiled and executed produces the original tree. * For more information and examples see the documentation for `Universe.reify`. diff --git a/src/reflect/scala/reflect/macros/Typers.scala b/src/reflect/scala/reflect/macros/Typers.scala index d7aec9b3ef..ec90ee8fe6 100644 --- a/src/reflect/scala/reflect/macros/Typers.scala +++ b/src/reflect/scala/reflect/macros/Typers.scala @@ -5,11 +5,11 @@ package macros /** * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> * - * A slice of [[scala.reflect.macros.Context the Scala macros context]] that + * A slice of [[scala.reflect.macros.BlackboxContext the Scala macros context]] that * partially exposes the type checker to macro writers. */ trait Typers { - self: Context => + self: BlackboxContext => /** Contexts that represent macros in-flight, including the current one. Very much like a stack trace, but for macros only. * Can be useful for interoperating with other macros and for imposing compiler-friendly limits on macro expansion. @@ -21,7 +21,7 @@ trait Typers { * Unlike `enclosingMacros`, this is a def, which means that it gets recalculated on every invocation, * so it might change depending on what is going on during macro expansion. */ - def openMacros: List[Context] + def openMacros: List[BlackboxContext] /** Information about one of the currently considered implicit candidates. * Candidates are used in plural form, because implicit parameters may themselves have implicit parameters, diff --git a/src/reflect/scala/reflect/macros/WhiteboxContext.scala b/src/reflect/scala/reflect/macros/WhiteboxContext.scala new file mode 100644 index 0000000000..76bc17746c --- /dev/null +++ b/src/reflect/scala/reflect/macros/WhiteboxContext.scala @@ -0,0 +1,43 @@ +package scala +package reflect +package macros + +/** + * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> + * + * The whitebox Scala macros context. + * + * See [[scala.reflect.macros.package the overview page]] for a description of how macros work. This documentation + * entry provides information on the API available to macro writers. + * + * A macro context wraps a compiler universe exposed in `universe` and having type [[scala.reflect.macros.Universe]]. + * This type is a refinement over the generic reflection API provided in [[scala.reflect.api.Universe]]. The + * extended Universe provides mutability for reflection artifacts (e.g. macros can change types of compiler trees, + * add annotation to symbols representing definitions, etc) and exposes some internal compiler functionality + * such as `Symbol.deSkolemize` or `Tree.attachments`. + * + * Another fundamental part of a macro context is `macroApplication`, which provides access to the tree undergoing + * macro expansion. Parts of this tree can be found in arguments of the corresponding macro implementations and + * in `prefix`, but `macroApplication` gives the full picture. + * + * Other than that, macro contexts provide facilities for typechecking, exploring the compiler's symbol table and + * enclosing trees and compilation units, evaluating trees, logging warnings/errors and much more. + * Refer to the documentation of top-level traits in this package to learn the details. + * + * If a macro def refers to a macro impl that uses `WhiteboxContext`, then this macro def becomes a whitebox macro, + * gaining the ability to refine the type of its expansion beyond its official return type, which enables a number of important use cases. + * Blackbox macros, i.e. the ones defined with `BlackboxContext`, can't do that, so they are less powerful. + * However blackbox macros are also going to enjoy better support than whitebox macros, so choose wisely. + * See the [[http://docs.scala-lang.org/overviews/macros.html Macros Guide]] for more information. + * + * @see `scala.reflect.macros.BlackboxContext` + */ +trait WhiteboxContext extends BlackboxContext { + /** @inheritdoc + */ + def openMacros: List[WhiteboxContext] + + /** @inheritdoc + */ + def enclosingMacros: List[WhiteboxContext] +}
\ No newline at end of file diff --git a/src/reflect/scala/reflect/macros/WhiteboxMacro.scala b/src/reflect/scala/reflect/macros/WhiteboxMacro.scala new file mode 100644 index 0000000000..1c581313eb --- /dev/null +++ b/src/reflect/scala/reflect/macros/WhiteboxMacro.scala @@ -0,0 +1,36 @@ +package scala.reflect +package macros + +/** + * <span class="badge badge-red" style="float: right;">EXPERIMENTAL</span> + * + * Traditionally macro implementations are defined as methods, + * but this trait provides an alternative way of encoding macro impls as + * bundles, traits which extend `scala.reflect.macros.BlackboxMacro` or`scala.reflect.macros.WhiteboxMacro` . + * + * Instead of: + * + * def impl[T: c.WeakTypeTag](c: WhiteboxContext)(x: c.Expr[Int]) = ... + * + * One can write: + * + * trait Impl extends WhiteboxMacro { + * def apply[T: c.WeakTypeTag](x: c.Expr[Int]) = ... + * } + * + * Without changing anything else at all. + * + * This language feature is useful in itself in cases when macro implementations + * are complex and need to be modularized. State of the art technique of addressing this need is quite heavyweight: + * http://docs.scala-lang.org/overviews/macros/overview.html#writing_bigger_macros. + * + * @see `scala.reflect.macros.BlackboxMacro` + */ +trait WhiteboxMacro { + /** The context to be used by the macro implementation. + * + * Vanilla macro implementations have to carry it in their signatures, however when a macro is a full-fledged module, + * it can define the context next to the implementation, makes implementation signature more lightweight. + */ + val c: WhiteboxContext +} diff --git a/src/reflect/scala/reflect/macros/package.scala b/src/reflect/scala/reflect/macros/package.scala index 2e2e8e79f8..6a8434a163 100644 --- a/src/reflect/scala/reflect/macros/package.scala +++ b/src/reflect/scala/reflect/macros/package.scala @@ -7,10 +7,22 @@ package reflect * The base package for Scala macros. * * Macros are functions that are called by the compiler during compilation. - * Within these functions the programmer has access to compiler APIs exposed in [[scala.reflect.macros.Context]]. + * Within these functions the programmer has access to compiler APIs. * For example, it is possible to generate, analyze and typecheck code. * * See the [[http://docs.scala-lang.org/overviews/macros.html Macros Guide]] on how to get started with Scala macros. */ package object macros { + /** The Scala macros context. + * + * In Scala 2.11, macros that were once the one are split into blackbox and whitebox macros, + * with the former being better supported and the latter being more powerful. You can read about + * the details of the split and the associated trade-offs in the [[http://docs.scala-lang.org/overviews/macros.html Macros Guide]]. + * + * `scala.reflect.macros.Context` follows this tendency and turns into `scala.reflect.macros.BlackboxContext` + * and `scala.reflect.macros.WhiteboxContext`. The original `Context` is left in place for compatibility reasons, + * but it is now deprecated, nudging the users to choose between blackbox and whitebox macros. + */ + @deprecated("Use BlackboxContext or WhiteboxContext instead", "2.11.0") + type Context = WhiteboxContext }
\ No newline at end of file diff --git a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala index 4d69a6673c..50b5843c59 100644 --- a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala +++ b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala @@ -314,8 +314,10 @@ trait JavaUniverseForce { self: runtime.JavaUniverse => definitions.TypeCreatorClass definitions.TreeCreatorClass definitions.LiftableClass - definitions.MacroClass - definitions.MacroContextClass + definitions.BlackboxMacroClass + definitions.WhiteboxMacroClass + definitions.BlackboxContextClass + definitions.WhiteboxContextClass definitions.MacroImplAnnotation definitions.StringContextClass definitions.QuasiquoteClass @@ -334,6 +336,7 @@ trait JavaUniverseForce { self: runtime.JavaUniverse => definitions.TupleClass definitions.FunctionClass definitions.AbstractFunctionClass + definitions.MacroContextType definitions.ProductRootClass definitions.Any_$eq$eq definitions.Any_$bang$eq diff --git a/src/reflect/scala/reflect/runtime/package.scala b/src/reflect/scala/reflect/runtime/package.scala index 41c1310e17..3a7688aa2c 100644 --- a/src/reflect/scala/reflect/runtime/package.scala +++ b/src/reflect/scala/reflect/runtime/package.scala @@ -26,7 +26,7 @@ package object runtime { package runtime { private[scala] object Macros { - def currentMirror(c: scala.reflect.macros.Context): c.Expr[universe.Mirror] = { + def currentMirror(c: scala.reflect.macros.BlackboxContext): c.Expr[universe.Mirror] = { import c.universe._ val runtimeClass = c.reifyEnclosingRuntimeClass if (runtimeClass.isEmpty) c.abort(c.enclosingPosition, "call site does not have an enclosing class") |