approximate type parameters and references by name

not as accurate, but simpler.

compile/api/APIUtil.scala

@@ -16,34 +16,6 @@ object APIUtil
 		new Modifiers( x(0), x(1), x(2), x(3), x(4), x(5), x(6) )
 	}
 
-	def verifyTypeParameters(s: SourceAPI): Boolean =
-	{
-		val check = new CheckTypeParameters
-		val invalid = check(s)
-		if(!invalid.isEmpty) println("References to undefined type parameters: " + invalid.mkString(", "))
-		invalid.isEmpty
-	}
-	private[this] class CheckTypeParameters extends Visit
-	{
-		private val defined = new HashSet[Int]
-		private val referenced = new HashSet[Int]
-		def apply(s: SourceAPI): List[Int] =
-		{
-			super.visitAPI(s)
-			(referenced filterNot defined).toList
-		}
-		override def visitTypeParameter(parameter: TypeParameter)
-		{
-			defined += parameter.id
-			super.visitTypeParameter(parameter)
-		}
-		override def visitParameterRef(ref: ParameterRef)
-		{
-			referenced += ref.id
-			super.visitParameterRef(ref)
-		}
-	}
-
 	def hasMacro(s: SourceAPI): Boolean =
 	{
 		val check = new HasMacro

compile/api/ClassToAPI.scala

@@ -172,9 +172,8 @@ object ClassToAPI
 		new api.TypeParameter(typeVariable(tp), emptyAnnotationArray, emptyTypeParameterArray, api.Variance.Invariant, NothingRef, upperBounds(tp.getBounds))
 
 	// needs to be stable across compilations
-	//  preferably, it would be a proper unique id based on de Bruijn index
-	def typeVariable[T <: GenericDeclaration](tv: TypeVariable[T]): Int =
-		reduceHash((name(tv.getGenericDeclaration) + " " + tv.getName).getBytes)
+	def typeVariable[T <: GenericDeclaration](tv: TypeVariable[T]): String =
+		name(tv.getGenericDeclaration) + " " + tv.getName
 
 	def reduceHash(in: Array[Byte]): Int =
 		(0 /: in)( (acc, b) => (acc * 43) ^ b)

compile/api/HashAPI.scala

@@ -6,21 +6,16 @@ package xsbt.api
 import scala.util
 import xsbti.api._
 import util.MurmurHash
-import TagTypeVariables.TypeVars
 import HashAPI.Hash
 
 object HashAPI
 {
 	type Hash = Int
 	def apply(a: SourceAPI): Hash =
-	{
-		/** de Bruijn levels for type parameters in source a and b*/
-		val tags = TagTypeVariables(a)
-		(new HashAPI(tags, false, true)).hashAPI(a)
-	}
+		(new HashAPI(false, true)).hashAPI(a)
 }
 
-final class HashAPI(tags: TypeVars, includePrivate: Boolean, includeParamNames: Boolean)
+final class HashAPI(includePrivate: Boolean, includeParamNames: Boolean)
 {
 	import scala.collection.mutable
 	import MurmurHash._
@@ -229,6 +224,7 @@ final class HashAPI(tags: TypeVars, includePrivate: Boolean, includeParamNames:
 	def hashTypeParameters(parameters: Seq[TypeParameter]) = hashSeq(parameters, hashTypeParameter)
 	def hashTypeParameter(parameter: TypeParameter)
 	{
+		hashString(parameter.id)
 		extend(parameter.variance.ordinal)
 		hashTypeParameters(parameter.typeParameters)
 		hashType(parameter.lowerBound)
@@ -267,10 +263,7 @@ final class HashAPI(tags: TypeVars, includePrivate: Boolean, includeParamNames:
 	def hashParameterRef(p: ParameterRef)
 	{
 		extend(ParameterRefHash)
-		tags.get(p.id) match {
-			case Some((a,b)) => extend(a); extend(b)
-			case None => extend(-1)
-		}
+		hashString(p.id)
 	}
 	def hashSingleton(s: Singleton)
 	{

compile/api/SameAPI.scala

@@ -39,7 +39,7 @@ object TopLevel
 	def definitions(i: Iterable[SourceAPI]) = SameAPI.separateDefinitions(i.toSeq.flatMap( _.definitions ))
 	def names(s: Iterable[Definition]): Set[String] = Set() ++ s.map(_.name)
 }
-	import TagTypeVariables.TypeVars
+
 /** Checks the API of two source files for equality.*/
 object SameAPI
 {
@@ -56,11 +56,7 @@ object SameAPI
 		println("\n=========== API #2 ================")
 		println(ShowAPI.show(b))*/
 
-		/** de Bruijn levels for type parameters in source a and b*/
-		val tagsA = TagTypeVariables(a)
-		val tagsB = TagTypeVariables(b)
-
-		val result = (new SameAPI(tagsA,tagsB, false, true)).check(a,b)
+		val result = (new SameAPI(false, true)).check(a,b)
 		val end = System.currentTimeMillis
 		//println(" API comparison took: " + (end - start) / 1000.0 + " s")
 		result
@@ -99,13 +95,11 @@ object SameAPI
 			case _ => true
 		}
 }
-/** Used to implement API equality.  All comparisons must be done between constructs in source files `a` and `b`.  For example, when doing:
-* `sameDefinitions(as, bs)`, `as` must be definitions from source file `a` and `bs` must be definitions from source file `b`.  This is in order
-* to properly handle type parameters, which must be computed for each source file and then referenced during comparison.
+/** Used to implement API equality.
 *
 * If `includePrivate` is true, `private` and `private[this]` members are included in the comparison.  Otherwise, those members are excluded.
 */
-class SameAPI(tagsA: TypeVars, tagsB: TypeVars, includePrivate: Boolean, includeParamNames: Boolean)
+class SameAPI(includePrivate: Boolean, includeParamNames: Boolean)
 {
 	import SameAPI._
 
@@ -304,13 +298,8 @@ class SameAPI(tagsA: TypeVars, tagsB: TypeVars, includePrivate: Boolean, include
 		debug(sameType(a.upperBound, b.upperBound), "Different upper bound") &&
 		sameTags(a.id, b.id)
 	}
-		// until dangling type parameter references are straightened out in API phase, approximate
-	def sameTags(a: Int, b: Int): Boolean =
-	{
-		val ta = tagsA.get(a)
-		val tb = tagsB.get(b)
-		debug(ta == tb, "Different type parameter bindings: " + ta + "(" + a + "), " + tb + "(" + b + ")")
-	}
+	def sameTags(a: String, b: String): Boolean =
+		debug(a == b, "Different type parameter bindings: " + a + ", " + b)
 
 	def sameType(a: Type, b: Type): Boolean =
 		samePending(a,b)(sameTypeDirect)

compile/interface/API.scala

@@ -126,9 +126,7 @@ final class API(val global: CallbackGlobal) extends Compat
 		else if(sym.isRoot || sym.isRootPackage) Constants.emptyType
 		else new xsbti.api.Projection(simpleType(in, pre), sym.nameString)
 	}
-
-	private def reference(sym: Symbol): xsbti.api.ParameterRef = new xsbti.api.ParameterRef(sym.id)
-
+	private def reference(sym: Symbol): xsbti.api.ParameterRef = new xsbti.api.ParameterRef(tparamID(sym))
 
 	private def annotations(in: Symbol, as: List[AnnotationInfo]): Array[xsbti.api.Annotation] = as.toArray[AnnotationInfo].map(annotation(in,_))
 	private def annotation(in: Symbol, a: AnnotationInfo) =
@@ -338,11 +336,12 @@ final class API(val global: CallbackGlobal) extends Compat
 		val variance = if(varianceInt < 0) Contravariant else if(varianceInt > 0) Covariant else Invariant
 		viewer(in).memberInfo(s) match
 		{
-			case TypeBounds(low, high) => new xsbti.api.TypeParameter( s.id, annots, typeParameters(in, s), variance, processType(in, low), processType(in, high) )
-			case PolyType(typeParams, base) => new xsbti.api.TypeParameter( s.id, annots, typeParameters(in, typeParams), variance, processType(in, base.bounds.lo),  processType(in, base.bounds.hi))
+			case TypeBounds(low, high) => new xsbti.api.TypeParameter( tparamID(s), annots, typeParameters(in, s), variance, processType(in, low), processType(in, high) )
+			case PolyType(typeParams, base) => new xsbti.api.TypeParameter( tparamID(s), annots, typeParameters(in, typeParams), variance, processType(in, base.bounds.lo),  processType(in, base.bounds.hi))
 			case x => error("Unknown type parameter info: " + x.getClass)
 		}
 	}
+	private def tparamID(s: Symbol) = s.fullName
 	private def selfType(in: Symbol, s: Symbol): xsbti.api.Type  =  processType(in, s.thisSym.typeOfThis)
 
 	private def classLike(in: Symbol, c: Symbol): ClassLike = classLikeCache.getOrElseUpdate( (in,c), mkClassLike(in, c))

compile/persist/APIFormats.scala

@@ -62,8 +62,8 @@ trait APIFormats extends FormatExtra
 	implicit def formatExistential(implicit t: Format[Type], tps: Format[Array[TypeParameter]]): Format[Existential] =
 		p2( (e: Existential) => (e.baseType, e.clause) )( new Existential(_,_) )(t,tps)
 
-	implicit def formatParameterRef(implicit i: Format[Int]): Format[ParameterRef] =
-		wrap[ParameterRef, Int](_.id, new ParameterRef(_))(i)
+	implicit def formatParameterRef(implicit i: Format[String]): Format[ParameterRef] =
+		wrap[ParameterRef, String](_.id, new ParameterRef(_))(i)
 
 	// cyclic with many formats
 	def formatType(implicit s: Format[SimpleType], a: Format[Annotated], st: Format[Structure], e: Format[Existential], po: Format[Polymorphic]): Format[Type] =
@@ -172,7 +172,7 @@ trait APIFormats extends FormatExtra
 	implicit def formatModifiers(implicit bf: Format[Byte]): Format[Modifiers] =
 		wrap[Modifiers, Byte]( modifiersToByte, byteToModifiers )
 
-	def formatTypeParameter(tps: Format[TypeParameter] => Format[Array[TypeParameter]])(implicit as: Format[Array[Annotation]], t: Format[Type], v: Format[Variance], i: Format[Int]): Format[TypeParameter] =
+	def formatTypeParameter(tps: Format[TypeParameter] => Format[Array[TypeParameter]])(implicit as: Format[Array[Annotation]], t: Format[Type], v: Format[Variance], i: Format[String]): Format[TypeParameter] =
 	{
 		lazy val ltps: Format[Array[TypeParameter]] = lazyFormat( tps(ltp) )
 		lazy val ltp = p6( (tp: TypeParameter) => (tp.id, tp.annotations, tp.typeParameters, tp.variance, tp.lowerBound, tp.upperBound))(new TypeParameter(_,_,_,_,_,_))(i, as, ltps, v, t, t)

interface/other

@@ -39,7 +39,7 @@ MethodParameter
 	modifier: ParameterModifier
 
 TypeParameter
-	id: Int
+	id: String
 	annotations: Annotation*
 	typeParameters : TypeParameter*
 	variance: Variance

interface/type

@@ -5,7 +5,7 @@ Type
 			prefix : SimpleType
 			id: String
 		ParameterRef
-			id: Int
+			id: String
 		Singleton
 			path: Path
 		EmptyType