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/* NSC -- new Scala compiler
* Copyright 2005-2006 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
package scala.tools.nsc.typechecker
import symtab.Flags._
import util.FreshNameCreator
import scala.collection.mutable.ListBuffer
/** <ul>
* <li>
* <code>caseArity</code>, <code>caseElement</code> implementations added
* to case classes
* </li>
* <li>
* <code>equals</code>, <code>hashCode</code> and </code>toString</code>
* methods are added to case classes, unless they are defined in the
* class or a baseclass different from <code>java.lang.Object</code>
* </li>
* <li>
* <code>toString</code> method is added to case objects, unless they
* are defined in the class or a baseclass different from
* <code>java.lang.Object</code>
* </li>
* </ul>
*/
trait SyntheticMethods requires Analyzer {
import global._ // the global environment
import definitions._ // standard classes and methods
import typer.{typed} // methods to type trees
/**
* @param templ ...
* @param clazz ...
* @param unit ...
* @return ...
*/
def addSyntheticMethods(templ: Template, clazz: Symbol, unit: CompilationUnit): Template = {
def hasImplementation(name: Name): Boolean = {
val sym = clazz.info.nonPrivateMember(name)
(sym.isTerm &&
(sym.owner == clazz ||
!(ObjectClass isNonBottomSubClass sym.owner) && !(sym hasFlag DEFERRED)))
}
def hasDirectImplementation(name: Name): Boolean = {
val sym = clazz.info.nonPrivateMember(name)
(sym.isTerm && sym.owner == clazz)
}
def syntheticMethod(name: Name, flags: Int, tpe: Type) =
newSyntheticMethod(name, flags | OVERRIDE, tpe)
def newSyntheticMethod(name: Name, flags: Int, tpe: Type) = {
val method = clazz.newMethod(clazz.pos, name) setFlag (flags) setInfo tpe
clazz.info.decls.enter(method)
method
}
def productSelectorMethod(n: int, accessor: Symbol): Tree = {
val method = syntheticMethod(newTermName("_"+n), FINAL, accessor.tpe)
typed(DefDef(method, vparamss => gen.mkAttributedRef(accessor)))
}
def caseElementMethod: Tree = {
val method = syntheticMethod(
nme.caseElement, FINAL, MethodType(List(IntClass.tpe), AnyClass.tpe))
val caseFields = clazz.caseFieldAccessors map gen.mkAttributedRef
typed(
DefDef(method, {vparamss =>
val doThrow:Tree = Throw(New(TypeTree(definitions.IndexOutOfBoundsExceptionClass.tpe),
List(List(Select(Ident(vparamss.head.head), nme.toString_)))))
if (caseFields.isEmpty) doThrow
else {
var i = caseFields.length
var cases = List(CaseDef(Ident(nme.WILDCARD), EmptyTree, doThrow))
for (val field <- caseFields.reverse) {
i = i - 1; cases = CaseDef(Literal(Constant(i)), EmptyTree, field) :: cases
}
Match(Ident(vparamss.head.head), cases)
}
}))
}
def caseArityMethod: Tree = {
val method = syntheticMethod(nme.caseArity, FINAL, PolyType(List(), IntClass.tpe))
typed(DefDef(method, vparamss => Literal(Constant(clazz.caseFieldAccessors.length))))
}
def caseNameMethod: Tree = {
val method = syntheticMethod(nme.caseName, FINAL, PolyType(List(), StringClass.tpe))
typed(DefDef(method, vparamss => Literal(Constant(clazz.name.decode))))
}
def productPrefixMethod: Tree = {
val method = syntheticMethod(nme.productPrefix, FINAL, PolyType(List(), StringClass.tpe))
typed(DefDef(method, vparamss => Literal(Constant(clazz.name.decode))))
}
def moduleToStringMethod: Tree = {
val method = syntheticMethod(nme.toString_, FINAL, MethodType(List(), StringClass.tpe))
typed(DefDef(method, vparamss => Literal(Constant(clazz.name.decode))))
}
def tagMethod: Tree = {
val method = syntheticMethod(nme.tag, FINAL, MethodType(List(), IntClass.tpe))
typed(DefDef(method, vparamss => Literal(Constant(clazz.tag))))
}
def forwardingMethod(name: Name): Tree = {
val target = getMember(ScalaRunTimeModule, "_" + name)
val paramtypes =
if (target.tpe.paramTypes.isEmpty) List()
else target.tpe.paramTypes.tail
val method = syntheticMethod(
name, 0, MethodType(paramtypes, target.tpe.resultType))
typed(DefDef(method, vparamss =>
Apply(gen.mkAttributedRef(target), This(clazz) :: (vparamss.head map Ident))))
}
def equalsMethod: Tree = {
val target = getMember(ScalaRunTimeModule, nme._equals)
val paramtypes =
if (target.tpe.paramTypes.isEmpty) List()
else target.tpe.paramTypes.tail
val method = syntheticMethod(
nme.equals_, 0, MethodType(paramtypes, target.tpe.resultType))
typed(DefDef(method, vparamss =>
Apply(
Select(
TypeApply(
Select(Ident(vparamss.head.head), Any_isInstanceOf),
List(TypeTree(clazz.tpe))),
Boolean_and),
List(
Apply(gen.mkAttributedRef(target), This(clazz) :: (vparamss.head map Ident))))));
}
def isSerializable(clazz: Symbol): Boolean =
!clazz.getAttributes(definitions.SerializableAttr).isEmpty
def readResolveMethod: Tree = {
// !!! the synthetic method "readResolve" should be private,
// but then it is renamed !!!
val method = newSyntheticMethod(nme.readResolve, PROTECTED,
MethodType(List(), ObjectClass.tpe))
typed(DefDef(method, vparamss => gen.mkAttributedRef(clazz.sourceModule)))
}
def newAccessorMethod(tree: Tree): Tree = tree match {
case DefDef(_, _, _, _, _, rhs) =>
val newAcc = tree.symbol.cloneSymbol
newAcc.name = unit.fresh.newName("" + tree.symbol.name + "$")
newAcc.setFlag(SYNTHETIC).resetFlag(ACCESSOR | PARAMACCESSOR)
newAcc.owner.info.decls enter newAcc
val result = typed(DefDef(newAcc, vparamss => rhs.duplicate))
log("new accessor method " + result)
result
}
def beanSetterOrGetter(sym: Symbol): Symbol =
if (!sym.name(0).isLetter) {
unit.error(sym.pos, "attribute `BeanProperty' can be applied only to fields that start with a letter")
NoSymbol
} else {
var name0 = sym.name
if (sym.isSetter) name0 = nme.setterToGetter(name0)
val prefix = if (sym.isSetter) "set" else
if (sym.tpe.resultType == BooleanClass.tpe) "is" else "get"
val arity = if (sym.isSetter) 1 else 0
val name1 = prefix + name0(0).toUpperCase + name0.subName(1, name0.length)
val sym1 = clazz.info.decl(name1)
if (sym1 != NoSymbol && sym1.tpe.paramTypes.length == arity) {
unit.error(sym.pos, "a definition of `"+name1+"' already exists in " + clazz)
NoSymbol
} else {
clazz.newMethod(sym.pos, name1)
.setInfo(sym.info)
.setFlag(sym.getFlag(DEFERRED | OVERRIDE | STATIC))
}
}
val ts = new ListBuffer[Tree]
def addBeanGetterMethod(sym: Symbol) = {
val getter = beanSetterOrGetter(sym)
if (getter != NoSymbol)
ts += typed(DefDef(
getter,
vparamss => if (sym hasFlag DEFERRED) EmptyTree else gen.mkAttributedRef(sym)))
}
def addBeanSetterMethod(sym: Symbol) = {
val setter = beanSetterOrGetter(sym)
if (setter != NoSymbol)
ts += typed(DefDef(
setter,
vparamss =>
if (sym hasFlag DEFERRED) EmptyTree
else Apply(gen.mkAttributedRef(sym), List(Ident(vparamss.head.head)))))
}
def isPublic(sym: Symbol) =
!sym.hasFlag(PRIVATE | PROTECTED) && sym.privateWithin == NoSymbol
if (!phase.erasedTypes) {
if (clazz hasFlag CASE) {
// case classes are implicitly declared serializable
clazz.attributes = Triple(SerializableAttr.tpe, List(), List()) :: clazz.attributes
for (val stat <- templ.body) {
if (stat.isDef && stat.symbol.isMethod && stat.symbol.hasFlag(CASEACCESSOR) && !isPublic(stat.symbol)) {
ts += newAccessorMethod(stat)
stat.symbol.resetFlag(CASEACCESSOR)
}
}
if (clazz.info.nonPrivateDecl(nme.tag) == NoSymbol) ts += tagMethod
if (clazz.isModuleClass) {
if (!hasImplementation(nme.toString_)) ts += moduleToStringMethod
} else {
if (!hasImplementation(nme.hashCode_)) ts += forwardingMethod(nme.hashCode_)
if (!hasImplementation(nme.toString_)) ts += forwardingMethod(nme.toString_)
if (!hasImplementation(nme.equals_)) ts += equalsMethod //forwardingMethod(nme.equals_)
}
// remove, after updating starr
if(templ.parents.contains { x:Tree => x.tpe == definitions.getClass("scala.CaseClass") }) {
if (!hasImplementation(nme.caseElement)) ts += caseElementMethod
if (!hasImplementation(nme.caseArity)) ts += caseArityMethod
if (!hasImplementation(nme.caseName)) ts += caseNameMethod
}
if (!hasDirectImplementation(nme.productPrefix)) ts += productPrefixMethod
val accessors = if(clazz hasFlag CASE) clazz.caseFieldAccessors else clazz.constrParamAccessors
for (val i <- 0 until accessors.length) {
val acc = accessors(i)
if (acc.name.toString != "_"+(i+1)) ts += productSelectorMethod(i+1, acc)
}
}
if (clazz.isModuleClass && isSerializable(clazz)) {
// If you serialize a singleton and then deserialize it twice,
// you will have two instances of your singleton, unless you implement
// the readResolve() method (see http://www.javaworld.com/javaworld/
// jw-04-2003/jw-0425-designpatterns_p.html)
if (!hasImplementation(nme.readResolve)) ts += readResolveMethod
}
if (!forCLDC)
for (val sym <- clazz.info.decls.toList)
if (!sym.getAttributes(BeanPropertyAttr).isEmpty)
if (sym.isGetter)
addBeanGetterMethod(sym)
else if (sym.isSetter)
addBeanSetterMethod(sym)
else if (sym.isMethod || sym.isType)
unit.error(sym.pos, "attribute `BeanProperty' is not applicable to " + sym)
}
val synthetics = ts.toList
copy.Template(
templ, templ.parents, if (synthetics.isEmpty) templ.body else templ.body ::: synthetics)
}
}
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