RFR 8199910: Compiler crashes with -g option and variables of intersection type inferred by `var`

Fri Mar 23 12:51:59 UTC 2018

On 23 March 2018 at 13:11, B. Blaser <bsrbnd at gmail.com> wrote:
> On 23 March 2018 at 11:57, Maurizio Cimadamore
> <maurizio.cimadamore at oracle.com> wrote:
>> Ping :-)
>
> Hello Maurizio,
>
> You'll still need another review but this looks good to me,
> Bernard

And I now see the "interest" (even if dangerous) of having
intersection types involving final classes [1]. So, I suggest to close
https://bugs.openjdk.java.net/browse/JDK-8189684

What do you think?

Thanks,
Bernard

[1] http://mail.openjdk.java.net/pipermail/compiler-dev/2017-November/011299.html

>> Maurizio
>>
>>
>> On 21/03/18 20:56, Maurizio Cimadamore wrote:
>>
>> Here's an updated webrev - passes all tests.
>>
>> In addition to the tests already provided, I also tweaked the LVTI test
>> harness to also use -g and report crashes (I verified that in this mode the
>> harness crashes w/o the patch).
>>
>> Webrev here:
>>
>> http://cr.openjdk.java.net/~mcimadamore/8199910-v3/
>>
>> Cheers
>> Maurizio
>>
>>
>> On 21/03/18 17:08, ShinyaYoshida wrote:
>>
>> Hi Maurizio,
>> Thank you for the pointing that.
>>
>> I've read the logic around your fix. It seems to me it's reasonable.
>> We don't need to handle intersection type in enterInner because inner
>> classes are handled triggered by a symbol of another part.
>>
>> I could confirm the test passes.
>> Please go ahead!
>>
>> Thank you for the opportunity to learn the logic around that.
>>
>> Regards,
>> shinyafox(Shinya Yoshida)
>>
>> 2018-03-22 1:26 GMT+09:00 Maurizio Cimadamore
>> <maurizio.cimadamore at oracle.com>:
>>>
>>> Attached is my take on the problem.
>>>
>>> As I said, we added some logic to handle this with multi-catch, but
>>> unfortunately the current logic only handle cases where you have a type like
>>> A & B and not cases where you have Foo<A & B>.
>>>
>>> I've enhanced the check to do a proper non-denotable visit on the type of
>>> the local variable, rather than just doing a simple check as before.
>>>
>>> Let me know what you think - and also if you'd like me to go ahead with
>>> it, or if you still want to take this.
>>>
>>> Cheers
>>> Maurizio
>>>
>>>
>>> On 21/03/18 16:09, Maurizio Cimadamore wrote:
>>>
>>> Hi Shinya,
>>> thanks for the fix; unfortunately, I believe it is not correct. An
>>> intersection type should be erased by the time we get here; we had a similar
>>> issue in the past with multicatch:
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-6999635
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-7005371
>>>
>>> I will take a closer look as to find out exactly what's going on; the fix
>>> for multicatch should have taken care for this one too...
>>>
>>> Maurizio
>>>
>>>
>>> On 21/03/18 02:53, ShinyaYoshida wrote:
>>>
>>> Hi all and Kishida,
>>>
>>> Thank you for reporting the issue.
>>>
>>> I've filed and created a patch:
>>> Bugs: https://bugs.openjdk.java.net/browse/JDK-8199910
>>> Webrev: http://cr.openjdk.java.net/~shinyafox/8199910/webrev/
>>>
>>> Could someone review this?
>>>
>>> If it's fine, I'll commit to jdk repo and I'd like to backport to jdk10
>>> after backport approval.
>>>
>>> Regards,
>>> shinyafox(Shinya Yoshida)
>>>
>>> 2018-03-21 10:54 GMT+09:00 kishida naoki <naokikishida at gmail.com>:
>>>>
>>>> Hi all!
>>>>
>>>> I'm glad that JDK 10 is released.
>>>> But I've faced a compiler bug with `var`.
>>>> I'm using the build 46.
>>>>
>>>> This code crashes the compiler with `-g` option.
>>>> ```
>>>> public class Main {
>>>>     void m() {
>>>>         var s = java.util.List.of("a", 1);
>>>>     }
>>>> }
>>>> ```
>>>>
>>>> $ javac Main.java -g
>>>> C:\src>javac Main.java -g
>>>> java.lang.AssertionError: Unexpected intersection type:
>>>> java.lang.Object&java.io.Serializable&java.lang.Comparable<? extends
>>>> java.lang.Object&java.io.Serializable&java.lang.Comparable<?>>
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.enterInner(ClassWriter.java:1043)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter$CWSignatureGenerator.classReference(ClassWriter.java:312)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.code.Types$SignatureGenerator.assembleClassSig(Types.java:5182)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.code.Types$SignatureGenerator.assembleSig(Types.java:5114)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter$CWSignatureGenerator.assembleSig(ClassWriter.java:291)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.code.Types$SignatureGenerator.assembleSig(Types.java:5225)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.code.Types$SignatureGenerator.assembleClassSig(Types.java:5201)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.code.Types$SignatureGenerator.assembleSig(Types.java:5114)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter$CWSignatureGenerator.assembleSig(ClassWriter.java:291)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.typeSig(ClassWriter.java:334)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.writeCode(ClassWriter.java:1271)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.writeMethod(ClassWriter.java:1158)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.writeMethods(ClassWriter.java:1653)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.writeClassFile(ClassWriter.java:1761)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.jvm.ClassWriter.writeClass(ClassWriter.java:1679)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:749)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1627)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1595)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:965)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:306)
>>>>         at
>>>> jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:165)
>>>>         at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
>>>>         at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)
>>>>
>>>> The cause is about intersection. The variable type that is infered
>>>> becomes as a type with intersection, and will crash the compiler when
>>>> generating a debug info.
>>>> These are no problem.
>>>>   var s=List.of("a");
>>>>   var s=List.of("a", 1, Optional.empty());
>>>>   var s=List.of("a", 1, List.of());
>>>>
>>>> Best regards.
>>>>
>>>> --
>>>> Naoki Kishida
>>>
>>>
>>>
>>>
>>
>>
>>