Bug: no line number for invokedynamic

[Maurizio Cimadamore]

This comes from here:

https://bugs.openjdk.java.net/browse/JDK-8010404

Back when developing JDK 8 - we had a feeling that having the debugger 
stop at lambda capture sites would be confusing - and so we disabled it.

I agree that in the stack trace case this decision seems to backfire a bit.

Maurizio


On 14/02/18 15:26, B. Blaser wrote:
> The line number is deliberately not emitted for dynamic callsites (but
> I don't know why?), see below.
> I hope this helps,
> Bernard
>
> diff -r b3a833c9c6e9
> src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java
> --- a/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java
>    Mon Feb 12 09:12:41 2018 +0100
> +++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java
>    Wed Feb 14 16:14:17 2018 +0100
> @@ -1649,9 +1649,9 @@
>           MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
>           genArgs(tree.args,
>                   msym.externalType(types).getParameterTypes());
> -        if (!msym.isDynamic()) {
> +//        if (!msym.isDynamic()) {
>               code.statBegin(tree.pos);
> -        }
> +//        }
>           result = m.invoke();
>       }
>
>
> On 14 February 2018 at 09:16, Vladimir Parfinenko
> <vparfinenko at excelsior-usa.com> wrote:
>> Hi all,
>>
>> I think I have found a minor bug. There is no line number information
>> for invokedynamic instructions generated for method handle or lambda
>> function.
>>
>> The problem can be reproduced using the example below and running it
>> like this:
>>
>>    $ javac Test.java
>>    $ rm A.class
>>    $ java Test
>>    Exception in thread "main" java.lang.NoClassDefFoundError: A
>>            at Test.main(Test.java:6)
>>    Caused by: java.lang.ClassNotFoundException: A
>>            ...
>>
>> The correct line number for this stack trace element would be 7.
>>
>> The line number table is missing an entry for invokedynamic:
>>
>>      Code:
>>        stack=2, locals=2, args_size=1
>>           0: invokestatic  #2                  // Method fortyTwo:()I
>>           3: invokedynamic #3,  0              // InvokeDynamic
>> #0:apply:()Ljava/util/function/Function;
>>           8: invokestatic  #4                  // Method
>> foo:(ILjava/util/function/Function;)Ljava/lang/Object;
>>          11: astore_1
>>          12: return
>>        LineNumberTable:
>>          line 6: 0
>>          line 5: 8
>>          line 9: 12
>>
>>
>> Regards,
>> Vladimir Parfinenko
>>
>>
>>
>> -- Test.java
>>
>> // line 1
>> public class Test {
>>      public static void main(String[] args) {
>>          Object res =
>>              foo(
>>                      fortyTwo(), // line 6
>>                      A::sqr      // line 7
>>              );
>>      }
>>
>>      public static Object foo(int x, java.util.function.Function<Integer,
>> Integer> f) {
>>          return null;
>>      }
>>
>>      public static int fortyTwo() {
>>          return 42;
>>      }
>> }
>>
>> class A {
>>      public static int sqr(int x) {
>>          return x * x;
>>      }
>> }
>>
>>