[llvm] [DebugInfo] Fix incorrect debug attribution for inlined allocas (PR #144345)

[Shivam Kunwar via llvm-commits]

phyBrackets wrote:

Thanks @SLTozer @dwblaikie for the inputs and review.

I agree that unconditionally clearing all alloca debug locations is too broad, I am not sure if we should handle directly it into stack protection pass by not inheriting debug locations from allocas , at this moment either the conditional approach sounds good, Clear debug locations only when there are conditional branches between the entry block and the call site, as you suggested. This preserves legitimate source locations (like` __builtin_alloca`) while fixing the attribution issue, but again traversing CFG comes with a cost, so definitely not an easy option, Or we should move with the current approach? 

I will take a look at it, until any other opinions and suggestions are welcome. 


https://github.com/llvm/llvm-project/pull/144345