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author | Jason Zaugg <jzaugg@gmail.com> | 2013-07-17 15:52:48 +1000 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2013-07-28 07:38:16 +0200 |
commit | 050b4c951c838699c2fe30cbf01b63942c63a299 (patch) | |
tree | b74d134cbfc14b3dad08162cf6126296ca285df6 | |
parent | 54cb6af7dbcf630a4f57e98f0099d77dd3b36693 (diff) | |
download | scala-050b4c951c838699c2fe30cbf01b63942c63a299.tar.gz scala-050b4c951c838699c2fe30cbf01b63942c63a299.tar.bz2 scala-050b4c951c838699c2fe30cbf01b63942c63a299.zip |
SI-7455 Drop dummy param for synthetic access constructor
Java synthesizes public constructors in private classes to
allow access from inner classes. The signature of
that synthetic constructor (known as a "access constructor")
has a dummy parameter appended to avoid overloading clashes.
javac chooses the type "Enclosing$1" for the dummy parameter
(called the "access constructor tag") which is either an
existing anonymous class or a synthesized class for this purpose.
In OpenJDK, this transformation is performed in:
langtools/src/share/classes/com/sun/tools/javac/comp/Lower.java
(Incidentally, scalac would just emits a byte-code public
constructor in this situation, rather than a private constructor /
access constructor pair.)
Scala parses the signature of the access contructor, and drops
the $outer parameter, but retains the dummy parameter. This causes
havoc when it tries to parse the bytecode for that anonymous class;
the class file parser doesn't have the enclosing type parameters
of Vector in scope and crash ensues.
In any case, we shouldn't allow user code to see that constructor;
it should only be called from within its own compilation unit.
This commit drops the dummy parameter from access constructor
signatures in class file parsing.
-rw-r--r-- | src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala | 13 | ||||
-rw-r--r-- | test/files/run/t7455.check | 4 | ||||
-rw-r--r-- | test/files/run/t7455/Outer.java | 31 | ||||
-rw-r--r-- | test/files/run/t7455/Test.scala | 30 |
4 files changed, 76 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala index da117540b4..4e5204f283 100644 --- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala +++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala @@ -626,7 +626,7 @@ abstract class ClassfileParser { sawPrivateConstructor = true in.skip(2); skipAttributes() } else { - if ((sflags & PRIVATE) != 0L && global.settings.optimise.value) { + if ((sflags & PRIVATE) != 0L && global.settings.optimise.value) { // TODO this should be !optimize, no? See c4181f656d. in.skip(4); skipAttributes() } else { val name = pool.getName(in.nextChar) @@ -636,7 +636,7 @@ abstract class ClassfileParser { info match { case MethodType(params, restpe) => // if this is a non-static inner class, remove the explicit outer parameter - val newParams = innerClasses getEntry currentClass match { + val paramsNoOuter = innerClasses getEntry currentClass match { case Some(entry) if !isScalaRaw && !isStatic(entry.jflags) => /* About `clazz.owner.isPackage` below: SI-5957 * For every nested java class A$B, there are two symbols in the scala compiler. @@ -650,6 +650,15 @@ abstract class ClassfileParser { case _ => params } + val newParams = paramsNoOuter match { + case (init :+ tail) if (jflags & JAVA_ACC_SYNTHETIC) != 0L => + // SI-7455 strip trailing dummy argument ("access constructor tag") from synthetic constructors which + // are added when an inner class needs to access a private constructor. + init + case _ => + paramsNoOuter + } + info = MethodType(newParams, clazz.tpe) } sym.setInfo(info) diff --git a/test/files/run/t7455.check b/test/files/run/t7455.check new file mode 100644 index 0000000000..0eb9342888 --- /dev/null +++ b/test/files/run/t7455.check @@ -0,0 +1,4 @@ +private[package <empty>] def <init>(x$1: String): Outer[E] +private[package <empty>] def <init>(): Outer$PrivateInner +private[package <empty>] def <init>(): Outer$PrivateStaticInner +private[package <empty>] def <init>(x$2: String): Outer$PublicInner diff --git a/test/files/run/t7455/Outer.java b/test/files/run/t7455/Outer.java new file mode 100644 index 0000000000..10c97a9150 --- /dev/null +++ b/test/files/run/t7455/Outer.java @@ -0,0 +1,31 @@ +public class Outer<E> { + public void elements() { + new C<E>() { + }; + } + + private Outer(String a) {} + + static class SubSelf extends Outer<String> { + public SubSelf() { super(""); } + } + + private class PrivateInner { + } + class SubPrivateInner extends PrivateInner { + } + + private class PublicInner { + private PublicInner(String a) {} + } + class SubPublicInner extends PublicInner { + public SubPublicInner() { super(""); } + } + + private static class PrivateStaticInner { + } + public static class SubPrivateStaticInner extends PrivateStaticInner { + } +} + +class C<E> {} diff --git a/test/files/run/t7455/Test.scala b/test/files/run/t7455/Test.scala new file mode 100644 index 0000000000..b23a724c78 --- /dev/null +++ b/test/files/run/t7455/Test.scala @@ -0,0 +1,30 @@ +import scala.tools.partest._ + +// javac adds dummy parameters of type Outer$1 to synthetic access constructors +// This test shows that we strip them from the signatures. If we don't, we trigger +// parsing of Outer$1 which can fail if it references type parameters of the Outer. +// +// OLD OUTPUT: +// private[package <empty>] def <init>(x$2: Outer$1): Outer$PrivateInner +// error: error while loading Outer$1, class file 't7455-run.obj/Outer$1.class' is broken +// (class java.util.NoSuchElementException/key not found: E) +// ... +object Test extends DirectTest { + override def code = "" + + def show { + val classpath = List(sys.props("partest.lib"), testOutput.path) mkString sys.props("path.separator") + val compiler = newCompiler("-cp", classpath, "-d", testOutput.path) + import compiler._, definitions._ + new compiler.Run + + for { + name <- Seq("Outer", "Outer$PrivateInner", "Outer$PrivateStaticInner", "Outer$PublicInner") + clazz = compiler.rootMirror.staticClass(name) + constr <- clazz.info.member(nme.CONSTRUCTOR).alternatives + } { + println(constr.defString) + fullyInitializeSymbol(constr) + } + } +} |