• Adjust documentation

• Change a comment for isDescribedByReg()
• Remove a dead code

• Use isEntryValue() from DIExpression

@aprantl I just updated the diff with documentation. Please let me know what do you think.

• Add documentation for the flag

LGTM. One last request: Could you please add (either to >the doxygen comment of isArgNotModified or to >LangRef.rst or SourceLevelDebugging.rst) an >explanation of the semantics of the flag. Ie.: What it is >used for and under what conditions a frontend should >generate it?

• Use MBB.instrs()

@dstenb Thanks for comments!

• Rename: VariableNotChanged ===> ArgumentNotModified
• Refactor test cases

If we wanted to support the DWARF 5 variants are there any semantic differences, or do we just need to rename the attributes?

@aprantl Yes, it will take only DWARF symbols (tag, attributes, operand) renaming.

• Rename: VariableNotChanged ===> ArgumentNotModified
• Refactor test cases

• Rename: VariableNotChanged ===> ArgumentNotModified
• Refactor a test case

• Rename: VariableNotChanged ===> ArgumentNotModified
• Refactor test cases

• Rename: VariableNotChanged ===> ArgumentNotModified
• Refactor a test case

• Rename: VariableNotChanged ===> ArgumentNotModified
• Add test case in test/Assembler/debug-info.ll

@aprantl I agree. Thanks for the comment!

@wolfgangp Thanks a lot for your comments! It has been addressed.

@aprantl Thanks for your comments!

LGTM as well! Thanks!

@vsk Thanks for the review!

@aprantl Thanks for the review! @vsk already answered all questions.

Please see the following lldb session:

@vsk Thanks for your comments and review! D43207 LGTM. I'll do that way.

@mattd Thanks! I don't see any obstacle to do that, it sounds good to me to set it even earlier.
@aprantl what do you think?

@aprantl All test cases pass. That is why RAUW has redundant check (getLocalFunctionMetadata for From and To). Maybe in some cases LLVM PASS just did not get the place where actually it updates the pointer to the DISubprogram (or it was pointer to the function before D42541) and if it is null at that particular point that does not mean that it clobbers dbg info (because it would be != than other metadata at the time).