[lldb/Interpreter] Make ScriptedInterface Object creation more generic

[medismailben]

This patch changes the way plugin objects used with Scripted Interfaces
are created.

Instead of implementing a different SWIG method to create the object for
every scripted interface, this patch makes the creation more generic by
re-using some of the ScriptedPythonInterface templated Dispatch code.

This patch also improves error handling of the object creation by
returning an llvm::Expected.

Signed-off-by: Med Ismail Bennani ismail@bennani.ma

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[bulbazord]

Works for me generally. I'm curious to know if some of these can be pure virtual function as Jonas mentioned.

[JDevlieghere]

LGTM

[DavidSpickett]

We still have a failure on Windows after the follow ups:

# .---command stderr------------
# | Cannot create an instance of the ScriptedProcessInterface!
# | UNREACHABLE executed at C:\Users\tcwg\david.spickett\llvm-project\lldb\include\lldb/Interpreter/Interfaces/ScriptedProcessInterface.h:29!
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
# | Stack dump:
# | 0.  Program arguments: c:\\users\\tcwg\\david.spickett\\build-llvm\\bin\\lldb-test.exe ir-memory-map C:\\Users\\tcwg\\david.spickett\\build-llvm\\tools\\lldb\\test\\Shell\\Expr\\Output\\TestIRMemoryMapWindows.test.tmp C:\\Users\\tcwg\\david.spickett\\llvm-project\\lldb\\test\\Shell\\Expr/Inputs/ir-memory-map-basic
# | 1.  HandleCommand(command = "run")
# | Exception Code: 0xC000001D
# |  #0 0x00007ff71e493e0c HandleAbort C:\Users\tcwg\david.spickett\llvm-project\llvm\lib\Support\Windows\Signals.inc:424:0
# |  #1 0x00007ffe20f30ef8 (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xa0ef8)
# |  #2 0x00007ffe20f32a50 (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xa2a50)
# |  #3 0x00007ff71e460358 llvm::llvm_unreachable_internal(char const *, char const *, unsigned int) C:\Users\tcwg\david.spickett\llvm-project\llvm\lib\Support\ErrorHandling.cpp:212:0
# |  #4 0x00007ff71e999fc4 lldb_private::ScriptedProcessInterface::CreatePluginObject(class llvm::StringRef, class lldb_private::ExecutionContext &, class std::shared_ptr<class lldb_private::StructuredData::Dictionary>, class lldb_private::StructuredData::Generic *) C:\Users\tcwg\david.spickett\llvm-project\lldb\include\lldb\Interpreter\Interfaces\ScriptedProcessInterface.h:28:0

I'm looking into it.

[DavidSpickett]

Somehow it is getting to:

  virtual llvm::Expected<StructuredData::GenericSP>
  CreatePluginObject(llvm::StringRef class_name, ExecutionContext &exe_ctx,
                     StructuredData::DictionarySP args_sp,
                     StructuredData::Generic *script_obj = nullptr) {
    llvm_unreachable(
        "Cannot create an instance of the ScriptedProcessInterface!");
  }

Starting to wonder if we're relying on some undefined order of evaluation somewhere.

[DavidSpickett]

Never mind, this could have been the result of using an incompatible Python version. I'll get a stacktrace with one I know is used on the bot.

[DavidSpickett]

02ef12d fixes the Windows test. If the behaviour seems suspicious to you, I can check more details of the build but I don't know anything about Scripted... so I'll need you to tell me what to look for.