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Diffstat (limited to 'src/main/scala/scala/async/AnfTransform.scala')
-rw-r--r-- | src/main/scala/scala/async/AnfTransform.scala | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/src/main/scala/scala/async/AnfTransform.scala b/src/main/scala/scala/async/AnfTransform.scala new file mode 100644 index 0000000..e1d7cd5 --- /dev/null +++ b/src/main/scala/scala/async/AnfTransform.scala @@ -0,0 +1,101 @@ +package scala.async + +import scala.reflect.macros.Context + +class AnfTransform[C <: Context](override val c: C) extends TransformUtils(c) { + import c.universe._ + import AsyncUtils._ + + object inline { + def transformToList(tree: Tree): List[Tree] = { + val stats :+ expr = anf.transformToList(tree) + expr match { + + case Apply(fun, args) if fun.toString.startsWith("scala.async.Async.await") => + val liftedName = c.fresh("await$") + stats :+ ValDef(NoMods, liftedName, TypeTree(), expr) :+ Ident(liftedName) + + case If(cond, thenp, elsep) => + // if type of if-else is Unit don't introduce assignment, + // but add Unit value to bring it into form expected by async transform + if (expr.tpe =:= definitions.UnitTpe) { + stats :+ expr :+ Literal(Constant(())) + } + else { + val liftedName = c.fresh("ifres$") + val varDef = + ValDef(Modifiers(Flag.MUTABLE), liftedName, TypeTree(expr.tpe), defaultValue(expr.tpe)) + val thenWithAssign = thenp match { + case Block(thenStats, thenExpr) => Block(thenStats, Assign(Ident(liftedName), thenExpr)) + case _ => Assign(Ident(liftedName), thenp) + } + val elseWithAssign = elsep match { + case Block(elseStats, elseExpr) => Block(elseStats, Assign(Ident(liftedName), elseExpr)) + case _ => Assign(Ident(liftedName), elsep) + } + val ifWithAssign = + If(cond, thenWithAssign, elseWithAssign) + stats :+ varDef :+ ifWithAssign :+ Ident(liftedName) + } + case _ => + stats :+ expr + } + } + + def transformToList(trees: List[Tree]): List[Tree] = trees match { + case fst :: rest => transformToList(fst) ++ transformToList(rest) + case Nil => Nil + } + } + + object anf { + def transformToList(tree: Tree): List[Tree] = tree match { + case Select(qual, sel) => + val stats :+ expr = inline.transformToList(qual) + stats :+ Select(expr, sel) + + case Apply(fun, args) => + val funStats :+ simpleFun = inline.transformToList(fun) + val argLists = args map inline.transformToList + val allArgStats = argLists flatMap (_.init) + val simpleArgs = argLists map (_.last) + funStats ++ allArgStats :+ Apply(simpleFun, simpleArgs) + + case Block(stats, expr) => + inline.transformToList(stats) ++ inline.transformToList(expr) + + case ValDef(mods, name, tpt, rhs) => + val stats :+ expr = inline.transformToList(rhs) + stats :+ ValDef(mods, name, tpt, expr).setSymbol(tree.symbol) + + case Assign(name, rhs) => + val stats :+ expr = inline.transformToList(rhs) + stats :+ Assign(name, expr) + + case If(cond, thenp, elsep) => + val stats :+ expr = inline.transformToList(cond) + val thenStats :+ thenExpr = inline.transformToList(thenp) + val elseStats :+ elseExpr = inline.transformToList(elsep) + stats :+ + c.typeCheck(If(expr, Block(thenStats, thenExpr), Block(elseStats, elseExpr))) + + //TODO + case Literal(_) | Ident(_) | This(_) | Match(_, _) | New(_) | Function(_, _) => List(tree) + + case TypeApply(fun, targs) => + val funStats :+ simpleFun = inline.transformToList(fun) + funStats :+ TypeApply(simpleFun, targs) + + //TODO + case DefDef(mods, name, tparams, vparamss, tpt, rhs) => List(tree) + + case ClassDef(mods, name, tparams, impl) => List(tree) + + case ModuleDef(mods, name, impl) => List(tree) + + case _ => + c.error(tree.pos, "Internal error while compiling `async` block") + ??? + } + } +} |