From 1a7de4314ac72bca81e31ad3ac0af7bee7eed26b Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Sun, 20 Jan 2013 12:31:22 +0100 Subject: SI-6666 Restrict hidden `this` access in self/super calls. Detect when classes (user authored or compiler generated) local to a self or super constructor argument would require premature access to the in-construction instance. The same restriction applies for classes and objects; for objects, the premature access would result in a null via MODULE$ field. A residual error has been lodged as SI-6997. I'd like to remove calls to `Symbol#outerClass` (which relies on the flaky flag INCONSTRUCTOR, see my comments in the JIRA issue for more discussion) from `LambdaLift` and `ExplicitOuter`, and instead use the stack of active self/super calls to know when to skip an enclosing class. That will obviate that flag. --- test/files/neg/t6666.check | 40 ++++++++++++++ test/files/neg/t6666.scala | 132 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 172 insertions(+) create mode 100644 test/files/neg/t6666.check create mode 100644 test/files/neg/t6666.scala (limited to 'test/files') diff --git a/test/files/neg/t6666.check b/test/files/neg/t6666.check new file mode 100644 index 0000000000..d0378173ea --- /dev/null +++ b/test/files/neg/t6666.check @@ -0,0 +1,40 @@ +t6666.scala:23: error: Implementation restriction: access of method x$2 in object O1 from anonymous class 2, would require illegal premature access to object O1 + F.byname(x) + ^ +t6666.scala:30: error: Implementation restriction: access of value x$3 in object O2 from anonymous class 3, would require illegal premature access to object O2 + F.byname(x) + ^ +t6666.scala:37: error: Implementation restriction: access of method x$4 in object O3 from anonymous class 4, would require illegal premature access to object O3 + F.hof(() => x) + ^ +t6666.scala:50: error: Implementation restriction: access of method x$6 in class C1 from anonymous class 7, would require illegal premature access to the unconstructed `this` of class C1 + F.byname(x) + ^ +t6666.scala:54: error: Implementation restriction: access of value x$7 in class C2 from anonymous class 8, would require illegal premature access to the unconstructed `this` of class C2 + F.byname(x) + ^ +t6666.scala:58: error: Implementation restriction: access of method x$8 in class C3 from anonymous class 9, would require illegal premature access to the unconstructed `this` of class C3 + F.hof(() => x) + ^ +t6666.scala:62: error: Implementation restriction: access of method x$9 in class C4 from object Nested$5, would require illegal premature access to the unconstructed `this` of class C4 + object Nested { def xx = x} + ^ +t6666.scala:68: error: Implementation restriction: access of method x$10 in class C5 from object Nested$6, would require illegal premature access to the unconstructed `this` of class C5 + object Nested { def xx = x} + ^ +t6666.scala:83: error: Implementation restriction: access of method x$12 in class C11 from anonymous class 12, would require illegal premature access to the unconstructed `this` of class C11 + F.byname(x) + ^ +t6666.scala:102: error: Implementation restriction: access of method x$13 in class C13 from anonymous class 13, would require illegal premature access to the unconstructed `this` of class C13 + F.hof(() => x) + ^ +t6666.scala:111: error: Implementation restriction: access of method x$14 in class C14 from object Nested$7, would require illegal premature access to the unconstructed `this` of class C14 + object Nested { def xx = x} + ^ +t6666.scala:122: error: Implementation restriction: access of method x$15 in class C15 from object Nested$8, would require illegal premature access to the unconstructed `this` of class C15 + object Nested { def xx = x} + ^ +t6666.scala:131: error: Implementation restriction: access of method foo$1 in class COuter from class CInner$1, would require illegal premature access to the unconstructed `this` of class COuter + class CInner extends C({foo}) + ^ +13 errors found diff --git a/test/files/neg/t6666.scala b/test/files/neg/t6666.scala new file mode 100644 index 0000000000..d37ffaf141 --- /dev/null +++ b/test/files/neg/t6666.scala @@ -0,0 +1,132 @@ +class C(a: Any) +object F { + def byname(a: => Any) = println(a) + def hof(a: () => Any) = println(a()) +} + +class COkay extends C(0) { + def this(a: Any) { + this() + def x = "".toString + F.byname(x) + } +} + +// +// The thunk's apply method accesses the MODULE$ +// field before it is set. +// +// 0: getstatic #23; //Field O1$.MODULE$:LO1$; +// 3: invokevirtual #26; //Method O1$.O1$$x$1:()Ljava/lang/String; +object O1 extends C({ + def x = "".toString + F.byname(x) +}) + +// java.lang.NullPointerException +// at O2$$anonfun$$init$$1.apply(:11) +object O2 extends C({ + lazy val x = "".toString + F.byname(x) +}) + +// java.lang.NullPointerException +// at O3$$anonfun$$init$$1.apply(:11) +object O3 extends C({ + def x = "".toString + F.hof(() => x) +}) + +// Okay, the nested classes don't get an outer pointer passed, +// just an extra param for `x: String`. +object O6 extends C({ + val x = "".toString + F.byname(x); F.hof(() => x); (new { val xx = x }.xx) +}) + + +class C1 extends C({ + def x = "".toString + F.byname(x) +}) +class C2 extends C({ + lazy val x = "".toString + F.byname(x) +}) +class C3 extends C({ + def x = "".toString + F.hof(() => x) +}) +class C4 extends C({ + def x = "".toString + object Nested { def xx = x} + Nested.xx +}) +class C5 extends C({ + def x = "".toString + val y = { + object Nested { def xx = x} + Nested.xx + } +}) + +// okay, for same reason as O6 +class C6 extends C({ + val x = "".toString + F.byname(x); F.hof(() => x); (new { val xx = x }.xx) +}) + +class C11(a: Any) { + def this() = { + this({ + def x = "".toString + F.byname(x) + }) + } +} + +// Crashes earlier in lazyVals. +// class C12(a: Any) { +// def this() = { +// this({ +// lazy val x = "".toString +// F.byname(x) +// }) +// } +// } + +class C13(a: Any) { + def this() = { + this({ + def x = "".toString + F.hof(() => x) + }) + } +} + +class C14(a: Any) { + def this() = { + this({ + def x = "".toString + object Nested { def xx = x} + Nested.xx + }) + } +} + +class C15(a: Any) { + def this() = { + this({ + def x = "".toString + val y = { + object Nested { def xx = x} + Nested.xx + } + }) + } +} + +class COuter extends C({ + def foo = 0 + class CInner extends C({foo}) +}) \ No newline at end of file -- cgit v1.2.3