The header file uses InterpOpcode type but doesn't include the header that defines it. While this works when included from files that already have the interpreter headers included (like interpexec.cpp), it violates header self-containment principles and could cause compilation errors if this header is included elsewhere. Add #include "../../interpreter/inc/intopsshared.h" after line 15 or before the BreakpointInfo struct definition to ensure the header is self-contained.

Disabling the SP validation check for all FEATURE_INTERPRETER builds is overly broad and reduces debug coverage. The check should only be skipped when actually in interpreter frames, not for all code when the interpreter feature is enabled. Consider checking if the current frame is an interpreter frame (e.g., using EECodeInfo::IsInterpretedCode on the current IP) before skipping the validation, similar to how the TARGET_WASM case is handled. This would preserve the debug check for JIT code while still allowing interpreter frames to work correctly.

You can StubManagers if there is one that recognizes the code pattern being used to make the indirect call. If the indirect call doesn't need too many instructions to reach the destination you could also enable single-stepping and get there that way.

I'm not sure why we'd enable single step here? The next line appears to set a breakpoint on the target already.

both breakpoint and single-stepping is unnecessary. If the breakpoint is where we expect execution to be after one instruction single step might be simpler.

its unnecessary to have both single-stepping and breakpoints on all the cases. If all the breakpoints are 1 instruction in the future perhaps its easier to rely on the single step rather than set all the breakpoints?

same as above

same thing

as a code factoring nit this function is already very long. I think it would be a little easier to follow if we factored some of this out into separate functions. Something like:

if(isInterpretter)
{
   return TrapInterpretterCodeStep(...)
}
else
{
    return TrapNativeCodeStep(...);
}

This seems suspicious. the debugger could do something like this:
EnableSingleStepping()
ApplyPatch(nextAddress)
DisableSingleStepping()

The debugger would expect the breakpoint is still set at the end of that sequence but this code appears to avoid setting a breakpoint when single stepping is also enabled.

My guess is you either want one special opcode with state tracking on the side to describe what happens when you hit it, or you want three opcodes representing BREAKPOINT, SINGLESTEP, BREAKPOINT_AND_SINGLESTEP.

Also there is a comment lower down with broader questions about the single stepping abstraction. If we decide to go with the debugger having an interpretter single step emulator then I'd expect INTOP_SINGLESTEP goes away.

I didn't expect to see entries in the debugger patch table when doing single stepping. That suggests the interpretter isn't really providing the normal single-stepping abstraction because the debugger doesn't track any patches when doing hardware single stepping.

I think we'd want one of:

1. a complete single step abstraction implemented at the interpreter layer with no dependencies on the debugger patch table
2. no single step at the interpretter layer and an InterpretterSingleStepEmulator at the debugger layer that implements single steps using interpretter breakpoints and predicting the next instruction as primitives.

Right now the implementation seems like a mixture of both, but closer to (2) than to (1).

I'll come back to this since I need to run for the moment, but I'm suspicious about the abstraction here. I think of these ExecutionControl APIs as being a layer below the debugger, something the debugger depends on. I did not expect them to be using the debugger patch table.