[clr-interp] Fix debugger issues in interpreter

[davidwrighton]

Fix a set of issues found when attempting to use the debugger on interpreted code. In general we need to get the interpreter byte codes if possible when attempting to use the EECodeInfo infrastructure. These changes helped me debug issues that appeared in interpmode=2

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[Copilot]

Pull request overview

This PR fixes debugger issues when working with interpreted code by ensuring that the EECodeInfo infrastructure can retrieve interpreter byte codes instead of interpreter stub addresses. The key addition is a new function GetInterpreterCodeFromInterpreterPrecodeIfPresent that unwraps interpreter precodes to get the actual bytecode addresses.

Key changes:

• New function GetInterpreterCodeFromInterpreterPrecodeIfPresent to extract interpreter bytecode addresses from interpreter precodes
• Helper method GetCodeForInterpreterOrJitted in MethodDesc for easier access
• Multiple DAC (Data Access Component) files updated to use the new function/helper when retrieving code addresses

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/coreclr/vm/stubmgr.cpp	Adds null check for pPrecode to prevent dereferencing null pointers
src/coreclr/vm/precode.h	Declares new function GetInterpreterCodeFromInterpreterPrecodeIfPresent
src/coreclr/vm/precode.cpp	Implements GetInterpreterCodeFromInterpreterPrecodeIfPresent to unwrap interpreter precodes
src/coreclr/vm/method.hpp	Adds GetCodeForInterpreterOrJitted helper method for MethodDesc
src/coreclr/debug/daccess/request.cpp	Updates code address retrieval to use new helper/function in multiple locations
src/coreclr/debug/daccess/enummem.cpp	Uses GetCodeForInterpreterOrJitted for stack trace exception handling
src/coreclr/debug/daccess/dacdbiimpl.cpp	Updates GetMethodRegionInfo and GetNativeCodeInfoForAddr to use new function/helper
src/coreclr/debug/daccess/daccess.cpp	Updates multiple debugger functions to use GetCodeForInterpreterOrJitted and GetInterpreterCodeFromInterpreterPrecodeIfPresent

[Copilot]

The GetCodeForInterpreterOrJitted method is only defined when FEATURE_INTERPRETER is enabled, but it is called unconditionally in multiple places (request.cpp, enummem.cpp, dacdbiimpl.cpp, daccess.cpp). This will cause compilation errors when FEATURE_INTERPRETER is not defined. Consider either: 1) removing the #ifdef guard around this method definition, or 2) adding #ifdef FEATURE_INTERPRETER guards around all call sites. Since GetInterpreterCodeFromInterpreterPrecodeIfPresent is already safe to call when FEATURE_INTERPRETER is not defined (it just returns the input unchanged), option 1 is recommended.

Suggested change

	#ifdef FEATURE_INTERPRETER
	PCODE GetCodeForInterpreterOrJitted()
	{
	WRAPPER_NO_CONTRACT;
	return GetInterpreterCodeFromInterpreterPrecodeIfPresent(GetNativeCode());
	}
	#endif
	PCODE GetCodeForInterpreterOrJitted()
	{
	WRAPPER_NO_CONTRACT;
	return GetInterpreterCodeFromInterpreterPrecodeIfPresent(GetNativeCode());
	}

[Copilot]

Type mismatch between declaration and implementation. The function is declared as taking TADDR in precode.h line 867, but implemented as taking PCODE in precode.cpp. While PCODE and TADDR are likely compatible types, this inconsistency should be fixed to match the declaration. Change the parameter type to TADDR to match the header file.

Suggested change

	PCODE GetInterpreterCodeFromInterpreterPrecodeIfPresent(PCODE codePointerMaybeInterpreterStub)
	PCODE GetInterpreterCodeFromInterpreterPrecodeIfPresent(TADDR codePointerMaybeInterpreterStub)

[Copilot]

There is an extra space before the opening parenthesis in the function call. Change 'GetNativeCode ()' to 'GetNativeCode()'.

Suggested change

	pReJitData->NativeCodeAddr = GetInterpreterCodeFromInterpreterPrecodeIfPresent(nativeCodeVersion.GetNativeCode ());
	pReJitData->NativeCodeAddr = GetInterpreterCodeFromInterpreterPrecodeIfPresent(nativeCodeVersion.GetNativeCode());