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Performance tweak for initialization check #11928

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Merged
merged 1 commit into from
Mar 30, 2021
Merged

Performance tweak for initialization check #11928

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38 changes: 24 additions & 14 deletions compiler/src/dotty/tools/dotc/transform/init/Checking.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,18 @@ object Checking {
safePromoted: mutable.Set[Potential], // Potentials that can be safely promoted
env: Env
) {
def withOwner(sym: Symbol): State = copy(env = env.withOwner(sym))
def withOwner[T](sym: Symbol)(op: State ?=> T): T =
val state = this.copy(env = env.withOwner(sym))
val res = op(using state)
this.visited = state.visited
res


def visit[T](eff: Effect)(op: State ?=> T): T =
val state: State = this.copy(path = path :+ eff.source, visited = this.visited + eff)
val res = op(using state)
this.visited = state.visited
res

def test(op: State ?=> Errors): Errors = {
val savedVisited = visited
Expand All @@ -58,15 +69,14 @@ object Checking {
traceIndented("Already checked " + eff.show, init)
Errors.empty
}
else {
state.visited = state.visited + eff
val state2: State = state.copy(path = state.path :+ eff.source)
eff match {
case eff: Promote => Checking.checkPromote(eff)(using state2)
case eff: FieldAccess => Checking.checkFieldAccess(eff)(using state2)
case eff: MethodCall => Checking.checkMethodCall(eff)(using state2)
else
state.visit(eff) {
eff match {
case eff: Promote => Checking.checkPromote(eff)
case eff: FieldAccess => Checking.checkFieldAccess(eff)
case eff: MethodCall => Checking.checkMethodCall(eff)
}
}
}
}
}

Expand Down Expand Up @@ -118,11 +128,11 @@ object Checking {
def checkConstructor(ctor: Symbol, tp: Type, source: Tree)(using state: State): Unit = traceOp("checking " + ctor.show, init) {
val cls = ctor.owner
val classDef = cls.defTree
if (!classDef.isEmpty) {
given State = state.withOwner(cls)
if (ctor.isPrimaryConstructor) checkClassBody(classDef.asInstanceOf[TypeDef])
else checkSecondaryConstructor(ctor)
}
if (!classDef.isEmpty)
state.withOwner(cls) {
if (ctor.isPrimaryConstructor) checkClassBody(classDef.asInstanceOf[TypeDef])
else checkSecondaryConstructor(ctor)
}
}

def checkSecondaryConstructor(ctor: Symbol)(using state: State): Unit = traceOp("checking " + ctor.show, init) {
Expand Down
2 changes: 1 addition & 1 deletion tests/init/neg/function1.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ class Foo {
val fun2: Int => Int = n => 1 + n + list.size
fun2(5)

List(5, 9).map(n => 2 + n + list.size) // error
List(5, 9).map(n => 2 + n + list.size)
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Why is this an error before? To what I understand final val is a "constant" (not assignable) value, so it gets initialized in a different order?

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Only final vals of constant types (such as false, 2, etc.) have different behavior due to const-folding.

We don't have a warning now, because at line 5, we already check the effect this.list!, thus the access this.list! is skipped here. If we comment out line 5, we will have a warning at this line.


final val list = List(1, 2, 3) // error

Expand Down