Withdrawn: 8269113: Javac throws when compiling switch (null)

[duke]

On Sun, 4 Jul 2021 18:13:26 GMT, Guoxiong Li <gli at openjdk.org> wrote:

> Hi all,
> 
> When we use `switch(null)` in the source code, the type of the selector is `BottomType`.
> So the statement `Type seltype = selector.type;` of the method `TransPatterns::handleSwitch` will get a `BottomType`.
> Then compiler mistakenly uses this `BottomType` to construct a new `VarSymbol`.
> 
> 
>             VarSymbol temp = new VarSymbol(Flags.SYNTHETIC,
>                     names.fromString("selector" + tree.pos + target.syntheticNameChar() + "temp"),
>                     seltype,     // <--------here is a BottomType
>                     currentMethodSym);
> 
> 
> At last, when the compiler uses the new `VarSymbol temp` to construct a new `JCVariableDecl`(the code shown as below), it crashes at the method `TreeMaker::Type` because the method `TreeMaker::Type` can't handle the type `BottomType`.
> 
> 
> statements.append(make.at(tree.pos).VarDef(temp, !hasNullCase ? attr.makeNullCheck(selector)
>                                                                           : selector));
> 
> 
> This patch changes the type from `BottomType` to `syms.objectType` and adds the corresponding test.
> Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

This pull request has been closed without being integrated.

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

PR: https://git.openjdk.java.net/jdk/pull/4679