Add NativeAOT.py for lldb visualization

[am11]

Adding @jbevain script from #115406 (comment).

Context:

(lldb) f 11
frame #11: 0x00000001005ff258 web04`_web04_Program___Main__(args=length=0) at Program.cs:11
   8   	  var testString = "Hello from NativeAOT!";
   9   	  var testArray = new int[] { 10, 20, 30 };
   10  	
-> 11  	  throw new InvalidOperationException($"{testString} {testArray.Length}");
   12  	}
   13  	
   14  	builder.Services.ConfigureHttpJsonOptions(options =>

Before:

(lldb) frame var testArray testString
(__Array<Int32> &) testArray = 0x00000004c0036550: {
  S_P_CoreLib_System_Array = {
    Object = {
      m_pEEType = 0x000000010126eef8
    }
    _numComponents = 3
  }
  m_NumComponents = 3
  m_Data = {}
}
(String &) testString = 0x0000000101025940: {
  Object = {
    m_pEEType = 0x00000001010e58b0
  }
  _stringLength = 21
  _firstChar = U+0048 u'H'
}

After:

(lldb) command script import /Users/adeel/projects/runtime/src/coreclr/nativeaot/BuildIntegration/NativeAOT.py
(lldb) frame var testArray testString
(__Array<Int32> &) testArray = 0x00000004c0036550 length=3: {
  [0] = 10
  [1] = 20
  [2] = 30
}
(String &) testString = 0x0000000101025940 "Hello from NativeAOT!": {
  Object = {}
  _stringLength = 21
  _firstChar = U+0048 u'H'
}

[dotnet-policy-service]

Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
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[agocke]

Nice. It's too bad that lldb doesn't support just directly embedding this in the symbols, but I guess this is the next best thing.

[jkotas]

path-to-ilcompiler-package is not constant. It changes every month.

Would it be better to include this in our LLDB debugger extension?

[am11]

It has same release cadence as SDK. File is next to NativeAOT.natvis.

dotnet-debugger-extensions and dotnet-sos have different release cadence. Also, debugger extension is not open source and unavailable in VMR distro builds; the only option there is dotnet-sos, so we will need to add it to two packages that way.

[jkotas]

NativeAOT.natvis is bundled into the .pdb file. People do not need to worry about explicitly setting a path to it. This python script is not like .natvis.

Yes, .NET debuggers are on a different shipping train and licensing plan than .NET itself.

[am11]

@hoyosjs, @mikem8361, should we emit it from https://github.com/dotnet/diagnostics/blob/ce653def0d1969dca0d518a95559b2acc3c6128c/src/SOS/SOS.InstallHelper/InstallHelper.cs#L65 at InstallLocation and include command script import line in ~/.lldbinit?

[MichalStrehovsky]

Looks like the Python script could be embedded into symbols and LLDB would pick it up but I only see it implemented for mach-O: https://github.com/llvm/llvm-project/blob/705e27c23474f3177670a791b5b54eefedee0cd8/lldb/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp#L202-L318

From what I see in the source code, the experience would be that LLDB will notify there's a debugging script and one then needs to make a gesture to allow it.

I like the approach from #115406 (comment) - the only unfortunate thing about that one is that the LLDB change to read the embedded formatters was only made 5 months ago so it'll take years until Linux distros pick that up.

[am11]

It can be implemented as SOS sub-command in C++ which gives us full control.