RFR: 8257740: Compiler crash when compiling type annotation on multicatch inside lambda

[Guoxiong Li]

On Thu, 10 Dec 2020 13:59:20 GMT, Joel Borggrén-Franck <jfranck at openjdk.org> wrote:

>> Hi all,
>> 
>> When translating a lambda expression to method, the method `LambdaToMethod.LambdaAnalyzerPreprocessor.LambdaTranslationContext.translate(final Symbol sym, LambdaSymbolKind skind)` creates new VarSymbol(s) according to the old VarSymbol(s). But this `translate` method doesn't set the field `data`  of the new VarSymbol. Maybe it is because the field `data` is unused in later phase.
>> 
>> Unfortunately, `com.sun.tools.javac.jvm.Code.fillExceptionParameterPositions` and `com.sun.tools.javac.jvm.Code.fillLocalVarPosition` would use the field `data` if the `data` is `ElementKind.EXCEPTION_PARAMETER`.
>> 
>> It causes the exception_index won't be set in `fillExceptionParameterPositions`. Later, if the exception_index is used, the compiler will crash with error `java.lang.AssertionError: exception_index is not set`.
>> 
>> This patch fixes it and adds corresponding test cases.
>> In my patch, I only set the field ` data`  if  the `data` is `ElementKind.EXCEPTION_PARAMETER`. Because I don't see another situation that the field `data` would be used.
>> 
>> Thank your for taking the time to review.
>> 
>> Best Regards.
>
> test/langtools/tools/javac/T8257740/T8257740_1.java line 27:
> 
>> 25:  * @test
>> 26:  * @bug 8257740
>> 27:  * @summary Compiler crash when compiling type annotation on uni-catch inside lambda
> 
> Did you manage to make it crash on a uni-catch as well?

I test the uni-catch locally by using this test case. The compiler crashes and the error message is same as multi-catch. But I don't know why the reporter only reproduce it by using multi-catch. My local environment is linux&x86_64.

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PR: https://git.openjdk.java.net/jdk/pull/1648