Skip to content

Cleanup LabelDefs #3365

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 7 commits into from
Oct 29, 2017
Merged

Cleanup LabelDefs #3365

Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
a753ad7
Cleanup LabelDefs
nicolasstucki Oct 22, 2017
09816bf
Reimplement LabelDefs using one TreeMap less
nicolasstucki Oct 22, 2017
b0747b0
Check that there are no Templates
nicolasstucki Oct 24, 2017
8c773d0
Remove Template from pattern match
nicolasstucki Oct 24, 2017
0995c60
Remove tpd. prefixes
nicolasstucki Oct 24, 2017
7d850ad
Cleanup imports
nicolasstucki Oct 24, 2017
e5dcf8e
Do not try to transform method if it has no labels
nicolasstucki Oct 27, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
100 changes: 27 additions & 73 deletions compiler/src/dotty/tools/backend/jvm/LabelDefs.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,38 +1,12 @@
package dotty.tools.backend.jvm

import dotty.tools.dotc.ast.Trees.Thicket
import dotty.tools.dotc.ast.{Trees, tpd}
import dotty.tools.dotc.ast.tpd
import dotty.tools.dotc.core.Contexts.Context
import dotty.tools.dotc.core.Types
import dotty.tools.dotc.core.Flags._
import dotty.tools.dotc.core.Symbols._
import dotty.tools.dotc.transform.MegaPhase._
import dotty.tools.dotc
import dotty.tools.dotc.backend.jvm.DottyPrimitives
import dotty.tools.dotc.core.Flags.FlagSet
import dotty.tools.dotc.transform.Erasure
import dotty.tools.dotc.transform.SymUtils._
import java.io.{File => JFile}

import scala.collection.generic.Clearable
import scala.collection.mutable
import scala.collection.mutable.{ListBuffer, ArrayBuffer}
import scala.reflect.ClassTag
import dotty.tools.io.{Directory, PlainDirectory, AbstractFile}
import scala.tools.asm.{ClassVisitor, FieldVisitor, MethodVisitor}
import scala.tools.nsc.backend.jvm.{BCodeHelpers, BackendInterface}
import dotty.tools.dotc.core._
import Periods._
import SymDenotations._
import Contexts._
import Types._
import Symbols._
import Denotations._
import Phases._
import java.lang.AssertionError
import dotty.tools.dotc.util.Positions.Position
import Decorators._
import tpd._
import Flags._
import StdNames.nme

/**
* Verifies that each Label DefDef has only a single address to jump back and
Expand Down Expand Up @@ -82,68 +56,48 @@ import StdNames.nme
* @author Dmitry Petrashko
*/
class LabelDefs extends MiniPhase {
def phaseName: String = "labelDef"
import tpd._

val queue = new ArrayBuffer[Tree]()
val beingAppended = new mutable.HashSet[Symbol]()
var labelLevel = 0
def phaseName: String = "labelDef"

override def transformDefDef(tree: tpd.DefDef)(implicit ctx: Context): tpd.Tree = {
if (tree.symbol is Flags.Label) tree
override def transformDefDef(tree: DefDef)(implicit ctx: Context): Tree = {
if (tree.symbol is Label) tree
else {
collectLabelDefs.clear
val newRhs = collectLabelDefs.transform(tree.rhs)
var labelDefs = collectLabelDefs.labelDefs
val labelDefs = collectLabelDefs(tree.rhs)

def putLabelDefsNearCallees = new TreeMap() {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I guess this can be a val

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, but I added a small optimization to not create the transformer if labelDefs is empty. Therefore it will be kept as a def.


override def transform(tree: tpd.Tree)(implicit ctx: Context): tpd.Tree = {
override def transform(tree: Tree)(implicit ctx: Context): Tree = {
tree match {
case t: Apply if labelDefs.contains(t.symbol) =>
val labelDef = labelDefs(t.symbol)
labelDefs -= t.symbol

val labelDef2 = transform(labelDef)
val labelDef2 = cpy.DefDef(labelDef)(rhs = transform(labelDef.rhs))
Block(labelDef2:: Nil, t)

case t: DefDef =>
assert(t.symbol is Label)
EmptyTree
case _ => if (labelDefs.nonEmpty) super.transform(tree) else tree
}
}
}

val res = cpy.DefDef(tree)(rhs = putLabelDefsNearCallees.transform(newRhs))

res
if (labelDefs.isEmpty) tree
else cpy.DefDef(tree)(rhs = putLabelDefsNearCallees.transform(tree.rhs))
}
}

object collectLabelDefs extends TreeMap() {

private def collectLabelDefs(tree: Tree)(implicit ctx: Context): mutable.HashMap[Symbol, DefDef] = {
// labelSymbol -> Defining tree
val labelDefs = new mutable.HashMap[Symbol, Tree]()

def clear = {
labelDefs.clear()
}

override def transform(tree: tpd.Tree)(implicit ctx: Context): tpd.Tree = tree match {
case t: Template => t
case t: Block =>
val r = super.transform(t)
r match {
case t: Block if t.stats.isEmpty => t.expr
case _ => r
}
case t: DefDef =>
assert(t.symbol is Flags.Label)
val r = super.transform(tree)
labelDefs(r.symbol) = r
EmptyTree
case t: Apply if t.symbol is Flags.Label =>
val sym = t.symbol
super.transform(tree)
case _ =>
super.transform(tree)
}
val labelDefs = new mutable.HashMap[Symbol, DefDef]()
new TreeTraverser {
override def traverse(tree: Tree)(implicit ctx: Context): Unit = tree match {
case t: DefDef =>
assert(t.symbol is Label)
labelDefs(t.symbol) = t
traverseChildren(t)
case _ => traverseChildren(tree)
}
}.traverse(tree)
labelDefs
}
}