From 75b44a6f723762cc3ebc911483beb2aec4cfee78 Mon Sep 17 00:00:00 2001 From: Eugene Burmako Date: Tue, 25 Dec 2012 14:09:33 +0100 Subject: [nomaster] macro expansions are now auto-duplicated The fix still requires macro developers to be careful about sharing trees by references, because attributed DefTrees will still bring trouble. However this is an improvement, because it doesn't make matters worse and automatically fixes situations similar to one in the test. A much more thorough discussion with a number of open questions left: http://groups.google.com/group/scala-internals/browse_thread/thread/492560d941b315cc Was fixed ages ago in master in one of the paradise backports. Never got to 2.10.x, but it's very useful, so I'm backporting it now. --- src/compiler/scala/tools/nsc/typechecker/Macros.scala | 8 +++++--- src/reflect/scala/reflect/internal/Trees.scala | 7 +++++-- 2 files changed, 10 insertions(+), 5 deletions(-) (limited to 'src') diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala index 816f977890..d6ec5f2cb0 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala @@ -713,9 +713,11 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces { var expectedTpe = expandee.tpe if (isNullaryInvocation(expandee)) expectedTpe = expectedTpe.finalResultType - var typechecked = typecheck("macro def return type", expanded, expectedTpe) - typechecked = typecheck("expected type", typechecked, pt) - typechecked + // also see http://groups.google.com/group/scala-internals/browse_thread/thread/492560d941b315cc + val expanded0 = duplicateAndKeepPositions(expanded) + val expanded1 = typecheck("macro def return type", expanded0, expectedTpe) + val expanded2 = typecheck("expected type", expanded1, pt) + expanded2 } finally { popMacroContext() } diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala index 2585b541ed..53b9b1d88e 100644 --- a/src/reflect/scala/reflect/internal/Trees.scala +++ b/src/reflect/scala/reflect/internal/Trees.scala @@ -1526,15 +1526,18 @@ trait Trees extends api.Trees { self: SymbolTable => } } - private lazy val duplicator = new Transformer { + private lazy val duplicator = new Duplicator(focusPositions = true) + private class Duplicator(focusPositions: Boolean) extends Transformer { override val treeCopy = newStrictTreeCopier override def transform(t: Tree) = { val t1 = super.transform(t) - if ((t1 ne t) && t1.pos.isRange) t1 setPos t.pos.focus + if ((t1 ne t) && t1.pos.isRange && focusPositions) t1 setPos t.pos.focus t1 } } + def duplicateAndKeepPositions(tree: Tree) = new Duplicator(focusPositions = false) transform tree + // ------ copiers ------------------------------------------- def copyDefDef(tree: Tree)( -- cgit v1.2.3