From 7b132f39b82e4fc47cd95eadce9e3f22da8c8d82 Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Tue, 31 May 2016 15:19:49 +1000 Subject: Avoid tree sharing with substituteThis The underlying transformer has a by-name parameter for the to provide the `to` tree, but this was strict in the layers of API above. Tree sharing is frowned upon in general as it leads to cross talk when, e.g., the erasure typechecker mutates the `tpe` field of the shared tree in different context. --- src/reflect/scala/reflect/api/Internals.scala | 6 +++--- src/reflect/scala/reflect/internal/Internals.scala | 2 +- src/reflect/scala/reflect/internal/Trees.scala | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) (limited to 'src/reflect') diff --git a/src/reflect/scala/reflect/api/Internals.scala b/src/reflect/scala/reflect/api/Internals.scala index 9b7112f011..2c8f84be0b 100644 --- a/src/reflect/scala/reflect/api/Internals.scala +++ b/src/reflect/scala/reflect/api/Internals.scala @@ -116,7 +116,7 @@ trait Internals { self: Universe => /** Substitute given tree `to` for occurrences of nodes that represent * `C.this`, where `C` refers to the given class `clazz`. */ - def substituteThis(tree: Tree, clazz: Symbol, to: Tree): Tree + def substituteThis(tree: Tree, clazz: Symbol, to: => Tree): Tree /** A factory method for `ClassDef` nodes. */ @@ -391,7 +391,7 @@ trait Internals { self: Universe => def substituteTypes(from: List[Symbol], to: List[Type]): Tree = internal.substituteTypes(tree, from, to) /** @see [[internal.substituteThis]] */ - def substituteThis(clazz: Symbol, to: Tree): Tree = internal.substituteThis(tree, clazz, to) + def substituteThis(clazz: Symbol, to: => Tree): Tree = internal.substituteThis(tree, clazz, to) } /** Extension methods for symbols */ @@ -1143,7 +1143,7 @@ trait Internals { self: Universe => /** @see [[InternalApi.substituteThis]] */ @deprecated("use `internal.substituteThis` instead or import `internal.decorators._` for infix syntax", "2.11.0") - def substituteThis(clazz: Symbol, to: Tree): Tree = internal.substituteThis(tree, clazz, to) + def substituteThis(clazz: Symbol, to: => Tree): Tree = internal.substituteThis(tree, clazz, to) } /** Scala 2.10 compatibility enrichments for Tree. */ diff --git a/src/reflect/scala/reflect/internal/Internals.scala b/src/reflect/scala/reflect/internal/Internals.scala index 1a48701ca7..a07441e3ca 100644 --- a/src/reflect/scala/reflect/internal/Internals.scala +++ b/src/reflect/scala/reflect/internal/Internals.scala @@ -29,7 +29,7 @@ trait Internals extends api.Internals { def freeTypes(tree: Tree): List[FreeTypeSymbol] = tree.freeTypes def substituteSymbols(tree: Tree, from: List[Symbol], to: List[Symbol]): Tree = tree.substituteSymbols(from, to) def substituteTypes(tree: Tree, from: List[Symbol], to: List[Type]): Tree = tree.substituteTypes(from, to) - def substituteThis(tree: Tree, clazz: Symbol, to: Tree): Tree = tree.substituteThis(clazz, to) + def substituteThis(tree: Tree, clazz: Symbol, to: => Tree): Tree = tree.substituteThis(clazz, to) def attachments(tree: Tree): Attachments { type Pos = Position } = tree.attachments def updateAttachment[T: ClassTag](tree: Tree, attachment: T): tree.type = tree.updateAttachment(attachment) def removeAttachment[T: ClassTag](tree: Tree): tree.type = tree.removeAttachment[T] diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala index c9dfd0c337..77097d892d 100644 --- a/src/reflect/scala/reflect/internal/Trees.scala +++ b/src/reflect/scala/reflect/internal/Trees.scala @@ -181,7 +181,7 @@ trait Trees extends api.Trees { def substituteTypes(from: List[Symbol], to: List[Type]): Tree = new TreeTypeSubstituter(from, to)(this) - def substituteThis(clazz: Symbol, to: Tree): Tree = + def substituteThis(clazz: Symbol, to: => Tree): Tree = new ThisSubstituter(clazz, to) transform this def hasExistingSymbol = (symbol ne null) && (symbol ne NoSymbol) -- cgit v1.2.3