RFR: 8213766: Assertion error in TypeAnnotations$TypeAnnotationPositions.resolveFrame

[Guoxiong Li]

Hi all,

This regression is caused by [PATCH-8078093](https://github.com/openjdk/jdk/commit/981c6dc2989b66f3691090c9f81e23d2b0a00087).

The method `DeferredAttr$DeferredAttrNode$StructuralStuckChecker.canLambdaBodyCompleteNormally` uses `attribSpeculativeLambda`. Later, the `ArgumentAttr.visitLambda(JCLambda that)` would be invoked, which sets the `ExplicitLambdaType.tree.type` to its `ExplicitLambdaType`. Note: currently, the `ExplicitLambdaType.tree` was not attributed and only the `ExplicitLambdaType.speculativeTree` was attributed.

Then, `DeferredAttr$RecoveryDeferredTypeMap.typeOf` would not invoke the method `recover` to attribute the `ExplicitLambdaType.tree` because the `owntype` is not equal to `Type.noType`. The code and some comments are shown below for you.

protected Type typeOf(DeferredType dt, Type pt) {
    Type owntype = super.typeOf(dt, pt);  // The `super.typeOf(dt, pt)` returns the `ExplicitLambdaType` which is set previously.
    return owntype == Type.noType ?
        recover(dt, pt) : owntype; // Here, the method `recover` is not invoked because `owntype == Type.noType` returns false.
}

Because the tree is not attributed, some regressions will occur, including this bug.

Although I found the cause of this bug, I think my patch is the simplest solution but it may be not the best solution.

Another solution is that method `DeferredAttr$DeferredAttrNode$StructuralStuckChecker.canLambdaBodyCompleteNormally` uses other way instead of using `attribSpeculativeLambda`. The old way which is before PATCH-8078093 is a candidate.

Any better solution is appreciated. Thank you for taking the time to review.

Best Regards.

-------------

Commit messages:
 - 8213766: Assertion error in TypeAnnotations.resolveFrame

Changes: https://git.openjdk.java.net/jdk/pull/2118/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2118&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8213766
  Stats: 58 lines in 2 files changed: 56 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2118.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2118/head:pull/2118

PR: https://git.openjdk.java.net/jdk/pull/2118