Re: The future of the daffodil DFDL schema debugger?

[Adam Rosien <ad...@rosien.net>]

> It looks like some of the code from java-debug can be reused without
involving JDI. The java-debug project could be viewed as an implementation
of the DAP communication protocol, coupled with JDI to provide
request/response values to DAP. For example, the `ProtocolServer` [3]
hard-codes the JDI, but there's an `AbstractProtocolServer` which only
handles the DAP communication (as a rough guess).

Update: I've successfully used the java-debug project from Microsoft to
speak DAP without requiring any JDI dependencies, for use in integrating
with the Daffodil Debugger interface.

On Mon, Apr 26, 2021 at 10:23 AM Adam Rosien <ad...@rosien.net> wrote:

> I'm currently seeing what it takes to get a minimal VS Code extension
> talking DAP over stdin/stdout to an external Scala process.
>
> On Fri, Apr 23, 2021 at 11:01 AM Adam Rosien <ad...@rosien.net> wrote:
>
>> I've looked at scala-debug-adapter a bit now, and it doesn't do very
>> much: there's some socket stuff and state management, but otherwise it
>> delegates to the underflying java-debug library which manages the DAP
>> protocol [1]. *That* library does assume use of JDI and supplies JVM-level
>> stuff to DAP (threads, etc.).
>>
>> So I think we don't want to rely on the code directly, but could extract
>> the outer "skeleton" of `DebugServer` [2] to use with Daffodil.
>>
>> It looks like some of the code from java-debug can be reused without
>> involving JDI. The java-debug project could be viewed as an implementation
>> of the DAP communication protocol, coupled with JDI to provide
>> request/response values to DAP. For example, the `ProtocolServer` [3]
>> hard-codes the JDI, but there's an `AbstractProtocolServer` which only
>> handles the DAP communication (as a rough guess).
>>
>> I think the next step is to play with the library in the prototype repo
>> to see what is really needed.
>>
>> .. Adam
>>
>> [1]
>> https://github.com/scalacenter/scala-debug-adapter/blob/main/core/src/main/scala/ch/epfl/scala/debugadapter/internal/DebugSession.scala#L35
>> extends java-debug `ProtocolServer`.
>> [2]
>> https://github.com/scalacenter/scala-debug-adapter/blob/main/core/src/main/scala/ch/epfl/scala/debugadapter/DebugServer.scala
>> [3]
>> https://github.com/microsoft/java-debug/blob/master/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/ProtocolServer.java#L52
>>
>> On Thu, Apr 22, 2021 at 1:31 PM John Wass <jw...@gmail.com> wrote:
>>
>>> > dig a bit to see if the DAP-only hooks can be reused without JDI coming
>>> along for the ride
>>>
>>> Cool, that would be good to dig at.  Big win if we can reuse it.
>>>
>>