Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

388 lines (339 sloc) 16.728 kb
/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package ast
import scala.reflect.internal.Flags.BYNAMEPARAM
import scala.reflect.internal.Flags.DEFAULTPARAM
import scala.reflect.internal.Flags.IMPLICIT
import scala.reflect.internal.Flags.PARAM
import scala.reflect.internal.Flags.PARAMACCESSOR
import scala.reflect.internal.Flags.PRESUPER
import scala.reflect.internal.Flags.TRAIT
import scala.compat.Platform.EOL
trait Trees extends scala.reflect.internal.Trees { self: Global =>
def treeLine(t: Tree): String =
if (t.pos.isDefined && t.pos.isRange) t.pos.lineContent.drop(t.pos.column - 1).take(t.pos.end - t.pos.start + 1)
else t.summaryString
def treeStatus(t: Tree, enclosingTree: Tree = null) = {
val parent = if (enclosingTree eq null) " " else " P#%5s".format(enclosingTree.id)
"[L%4s%8s] #%-6s %-15s %-10s // %s".format(t.pos.safeLine, parent, t.id, t.pos.show, t.shortClass, treeLine(t))
}
def treeSymStatus(t: Tree) = {
val line = if (t.pos.isDefined) "line %-4s".format(t.pos.safeLine) else " "
"#%-5s %s %-10s // %s".format(t.id, line, t.shortClass,
if (t.symbol ne NoSymbol) "(" + t.symbol.fullLocationString + ")"
else treeLine(t)
)
}
// --- additional cases --------------------------------------------------------
/** Only used during parsing */
case class Parens(args: List[Tree]) extends Tree
/** Documented definition, eliminated by analyzer */
case class DocDef(comment: DocComment, definition: Tree)
extends Tree {
override def symbol: Symbol = definition.symbol
override def symbol_=(sym: Symbol) { definition.symbol = sym }
override def isDef = definition.isDef
override def isTerm = definition.isTerm
override def isType = definition.isType
}
/** Array selection `<qualifier> . <name>` only used during erasure */
case class SelectFromArray(qualifier: Tree, name: Name, erasure: Type)
extends RefTree with TermTree
/** Derived value class injection (equivalent to: `new C(arg)` after erasure); only used during erasure.
* The class `C` is stored as a tree attachment.
*/
case class InjectDerivedValue(arg: Tree)
extends SymTree with TermTree
class PostfixSelect(qual: Tree, name: Name) extends Select(qual, name)
/** emitted by typer, eliminated by refchecks */
case class TypeTreeWithDeferredRefCheck()(val check: () => TypeTree) extends TypTree
// --- factory methods ----------------------------------------------------------
/** Factory method for a primary constructor super call `super.<init>(args_1)...(args_n)`
*/
def PrimarySuperCall(argss: List[List[Tree]]): Tree = argss match {
case Nil => Apply(gen.mkSuperInitCall, Nil)
case xs :: rest => rest.foldLeft(Apply(gen.mkSuperInitCall, xs): Tree)(Apply.apply)
}
/** Generates a template with constructor corresponding to
*
* constrmods (vparams1_) ... (vparams_n) preSuper { presupers }
* extends superclass(args_1) ... (args_n) with mixins { self => body }
*
* This gets translated to
*
* extends superclass with mixins { self =>
* presupers' // presupers without rhs
* vparamss // abstract fields corresponding to value parameters
* def <init>(vparamss) {
* presupers
* super.<init>(args)
* }
* body
* }
*/
def Template(parents: List[Tree], self: ValDef, constrMods: Modifiers, vparamss: List[List[ValDef]], body: List[Tree], superPos: Position): Template = {
/* Add constructor to template */
// create parameters for <init> as synthetic trees.
var vparamss1 = mmap(vparamss) { vd =>
atPos(vd.pos.focus) {
val mods = Modifiers(vd.mods.flags & (IMPLICIT | DEFAULTPARAM | BYNAMEPARAM) | PARAM | PARAMACCESSOR)
ValDef(mods withAnnotations vd.mods.annotations, vd.name, vd.tpt.duplicate, vd.rhs.duplicate)
}
}
val (edefs, rest) = body span treeInfo.isEarlyDef
val (evdefs, etdefs) = edefs partition treeInfo.isEarlyValDef
val gvdefs = evdefs map {
case vdef @ ValDef(_, _, tpt, _) =>
copyValDef(vdef)(
// atPos for the new tpt is necessary, since the original tpt might have no position
// (when missing type annotation for ValDef for example), so even though setOriginal modifies the
// position of TypeTree, it would still be NoPosition. That's what the author meant.
tpt = atPos(vdef.pos.focus)(TypeTree() setOriginal tpt setPos tpt.pos.focus),
rhs = EmptyTree
)
}
val lvdefs = evdefs collect { case vdef: ValDef => copyValDef(vdef)(mods = vdef.mods | PRESUPER) }
val constrs = {
if (constrMods hasFlag TRAIT) {
if (body forall treeInfo.isInterfaceMember) List()
else List(
atPos(wrappingPos(superPos, lvdefs)) (
DefDef(NoMods, nme.MIXIN_CONSTRUCTOR, List(), ListOfNil, TypeTree(), Block(lvdefs, Literal(Constant())))))
} else {
// convert (implicit ... ) to ()(implicit ... ) if its the only parameter section
if (vparamss1.isEmpty || !vparamss1.head.isEmpty && vparamss1.head.head.mods.isImplicit)
vparamss1 = List() :: vparamss1;
val superRef: Tree = atPos(superPos)(gen.mkSuperInitCall)
val superCall = pendingSuperCall // we can't know in advance which of the parents will end up as a superclass
// this requires knowing which of the parents is a type macro and which is not
// and that's something that cannot be found out before typer
// (the type macros aren't in the trunk yet, but there is a plan for them to land there soon)
// this means that we don't know what will be the arguments of the super call
// therefore here we emit a dummy which gets populated when the template is named and typechecked
List(
// TODO: previously this was `wrappingPos(superPos, lvdefs ::: argss.flatten)`
// is it going to be a problem that we can no longer include the `argss`?
atPos(wrappingPos(superPos, lvdefs)) (
DefDef(constrMods, nme.CONSTRUCTOR, List(), vparamss1, TypeTree(), Block(lvdefs ::: List(superCall), Literal(Constant())))))
}
}
constrs foreach (ensureNonOverlapping(_, parents ::: gvdefs, focus=false))
// Field definitions for the class - remove defaults.
val fieldDefs = vparamss.flatten map (vd => copyValDef(vd)(mods = vd.mods &~ DEFAULTPARAM, rhs = EmptyTree))
Template(parents, self, gvdefs ::: fieldDefs ::: constrs ::: etdefs ::: rest)
}
/** Construct class definition with given class symbol, value parameters,
* supercall arguments and template body.
*
* @param sym the class symbol
* @param constrMods the modifiers for the class constructor, i.e. as in `class C private (...)`
* @param vparamss the value parameters -- if they have symbols they
* should be owned by `sym`
* @param body the template statements without primary constructor
* and value parameter fields.
*/
def ClassDef(sym: Symbol, constrMods: Modifiers, vparamss: List[List[ValDef]], body: List[Tree], superPos: Position): ClassDef = {
// "if they have symbols they should be owned by `sym`"
assert(
mforall(vparamss)(p => (p.symbol eq NoSymbol) || (p.symbol.owner == sym)),
((mmap(vparamss)(_.symbol), sym))
)
ClassDef(sym,
Template(sym.info.parents map TypeTree,
if (sym.thisSym == sym || phase.erasedTypes) emptyValDef else ValDef(sym.thisSym),
constrMods, vparamss, body, superPos))
}
// --- subcomponents --------------------------------------------------
object treeInfo extends {
val global: Trees.this.type = self
} with TreeInfo
lazy val treePrinter = newTreePrinter()
// --- additional cases in operations ----------------------------------
override protected def xtraverse(traverser: Traverser, tree: Tree): Unit = tree match {
case Parens(ts) =>
traverser.traverseTrees(ts)
case DocDef(comment, definition) =>
traverser.traverse(definition)
case SelectFromArray(qualifier, selector, erasure) =>
traverser.traverse(qualifier)
case InjectDerivedValue(arg) =>
traverser.traverse(arg)
case TypeTreeWithDeferredRefCheck() =>
// (and rewrap the result? how to update the deferred check? would need to store wrapped tree instead of returning it from check)
case _ => super.xtraverse(traverser, tree)
}
trait TreeCopier extends super.InternalTreeCopierOps {
def DocDef(tree: Tree, comment: DocComment, definition: Tree): DocDef
def SelectFromArray(tree: Tree, qualifier: Tree, selector: Name, erasure: Type): SelectFromArray
def InjectDerivedValue(tree: Tree, arg: Tree): InjectDerivedValue
def TypeTreeWithDeferredRefCheck(tree: Tree): TypeTreeWithDeferredRefCheck
}
def newStrictTreeCopier: TreeCopier = new StrictTreeCopier
def newLazyTreeCopier: TreeCopier = new LazyTreeCopier
class StrictTreeCopier extends super.StrictTreeCopier with TreeCopier {
def DocDef(tree: Tree, comment: DocComment, definition: Tree) =
new DocDef(comment, definition).copyAttrs(tree)
def SelectFromArray(tree: Tree, qualifier: Tree, selector: Name, erasure: Type) =
new SelectFromArray(qualifier, selector, erasure).copyAttrs(tree)
def InjectDerivedValue(tree: Tree, arg: Tree) =
new InjectDerivedValue(arg).copyAttrs(tree)
def TypeTreeWithDeferredRefCheck(tree: Tree) = tree match {
case dc@TypeTreeWithDeferredRefCheck() => new TypeTreeWithDeferredRefCheck()(dc.check).copyAttrs(tree)
}
}
class LazyTreeCopier extends super.LazyTreeCopier with TreeCopier {
def DocDef(tree: Tree, comment: DocComment, definition: Tree) = tree match {
case t @ DocDef(comment0, definition0)
if (comment0 == comment) && (definition0 == definition) => t
case _ => this.treeCopy.DocDef(tree, comment, definition)
}
def SelectFromArray(tree: Tree, qualifier: Tree, selector: Name, erasure: Type) = tree match {
case t @ SelectFromArray(qualifier0, selector0, _)
if (qualifier0 == qualifier) && (selector0 == selector) => t
case _ => this.treeCopy.SelectFromArray(tree, qualifier, selector, erasure)
}
def InjectDerivedValue(tree: Tree, arg: Tree) = tree match {
case t @ InjectDerivedValue(arg0)
if (arg0 == arg) => t
case _ => this.treeCopy.InjectDerivedValue(tree, arg)
}
def TypeTreeWithDeferredRefCheck(tree: Tree) = tree match {
case t @ TypeTreeWithDeferredRefCheck() => t
case _ => this.treeCopy.TypeTreeWithDeferredRefCheck(tree)
}
}
class Transformer extends super.Transformer {
def transformUnit(unit: CompilationUnit) {
try unit.body = transform(unit.body)
catch {
case ex: Exception =>
println(supplementErrorMessage("unhandled exception while transforming "+unit))
throw ex
}
}
}
// used when a phase is disabled
object noopTransformer extends Transformer {
override def transformUnit(unit: CompilationUnit): Unit = {}
}
override protected def xtransform(transformer: super.Transformer, tree: Tree): Tree = tree match {
case DocDef(comment, definition) =>
transformer.treeCopy.DocDef(tree, comment, transformer.transform(definition))
case SelectFromArray(qualifier, selector, erasure) =>
transformer.treeCopy.SelectFromArray(
tree, transformer.transform(qualifier), selector, erasure)
case InjectDerivedValue(arg) =>
transformer.treeCopy.InjectDerivedValue(
tree, transformer.transform(arg))
case TypeTreeWithDeferredRefCheck() =>
transformer.treeCopy.TypeTreeWithDeferredRefCheck(tree)
}
object resetPos extends Traverser {
override def traverse(t: Tree) {
if (t != EmptyTree) t.setPos(NoPosition)
super.traverse(t)
}
}
/** resets symbol and tpe fields in a tree, @see ResetAttrs
*/
// def resetAllAttrs[A<:Tree](x:A): A = { new ResetAttrsTraverser().traverse(x); x }
// def resetLocalAttrs[A<:Tree](x:A): A = { new ResetLocalAttrsTraverser().traverse(x); x }
def resetAllAttrs(x: Tree, leaveAlone: Tree => Boolean = null): Tree = new ResetAttrs(false, leaveAlone).transform(x)
def resetLocalAttrs(x: Tree, leaveAlone: Tree => Boolean = null): Tree = new ResetAttrs(true, leaveAlone).transform(x)
def resetLocalAttrsKeepLabels(x: Tree, leaveAlone: Tree => Boolean = null): Tree = new ResetAttrs(true, leaveAlone, true).transform(x)
/** A transformer which resets symbol and tpe fields of all nodes in a given tree,
* with special treatment of:
* TypeTree nodes: are replaced by their original if it exists, otherwise tpe field is reset
* to empty if it started out empty or refers to local symbols (which are erased).
* TypeApply nodes: are deleted if type arguments end up reverted to empty
* This(pkg) nodes where pkg is a package: these are kept.
*
* (bq:) This transformer has mutable state and should be discarded after use
*/
private class ResetAttrs(localOnly: Boolean, leaveAlone: Tree => Boolean = null, keepLabels: Boolean = false) {
val debug = settings.debug.value
val trace = scala.tools.nsc.util.trace when debug
val locals = util.HashSet[Symbol](8)
val orderedLocals = scala.collection.mutable.ListBuffer[Symbol]()
def registerLocal(sym: Symbol) {
if (sym != null && sym != NoSymbol) {
if (debug && !(locals contains sym)) orderedLocals append sym
locals addEntry sym
}
}
class MarkLocals extends self.Traverser {
def markLocal(tree: Tree) {
if (tree.symbol != null && tree.symbol != NoSymbol) {
val sym = tree.symbol
registerLocal(sym)
registerLocal(sym.sourceModule)
registerLocal(sym.moduleClass)
registerLocal(sym.companionClass)
registerLocal(sym.companionModule)
sym match {
case sym: TermSymbol => registerLocal(sym.referenced)
case _ => ;
}
}
}
override def traverse(tree: Tree) = {
tree match {
case _: DefTree | Function(_, _) | Template(_, _, _) =>
markLocal(tree)
case _ =>
tree
}
super.traverse(tree)
}
}
class Transformer extends self.Transformer {
override def transform(tree: Tree): Tree = {
if (leaveAlone != null && leaveAlone(tree))
tree
else
super.transform {
tree match {
case tree if !tree.canHaveAttrs =>
tree
case tpt: TypeTree =>
if (tpt.original != null)
transform(tpt.original)
else if (tpt.tpe != null && (tpt.wasEmpty || (tpt.tpe exists (tp => locals contains tp.typeSymbol)))) {
tpt.duplicate.clearType()
}
else tree
case TypeApply(fn, args) if args map transform exists (_.isEmpty) =>
transform(fn)
case This(_) if tree.symbol != null && tree.symbol.isPackageClass =>
tree
case _ =>
val dupl = tree.duplicate
if (tree.hasSymbolField && (!localOnly || (locals contains tree.symbol)) && !(keepLabels && tree.symbol.isLabel))
dupl.symbol = NoSymbol
dupl.clearType()
}
}
}
}
def transform(x: Tree): Tree = {
if (localOnly)
new MarkLocals().traverse(x)
if (localOnly && debug) {
assert(locals.size == orderedLocals.size)
val msg = orderedLocals.toList filter {_ != NoSymbol} map {" " + _} mkString EOL
trace("locals (%d total): %n".format(orderedLocals.size))(msg)
}
new Transformer().transform(x)
}
}
/* New pattern matching cases:
case Parens(expr) (only used during parsing)
case DocDef(comment, defn) => (eliminated by typer)
case TypeTreeWithDeferredRefCheck() => (created and eliminated by typer)
case SelectFromArray(_, _, _) => (created and eliminated by erasure)
case InjectDerivedValue(_) => (created and eliminated by erasure)
*/
}
Jump to Line
Something went wrong with that request. Please try again.