[llvm] [debug] Support 32-bit column number in DILocation (PR #201269)

[Jeremy Morse via llvm-commits]

jmorse wrote:

Hmmm -- if I understand right, what you need overall is a key/index to access more Julia IR information at the end of compilation, that gets preserved like source locations do. Would it be feasible to instead just adopt the line-number field of `DILocations` to store that index? That would force you to recover the true line-number from the index / Julia IR at the end of compilation, but it'd be compatible with the future source-location changes and avoids the need for abnormal layouts of classes / custom builds of LLVM.

@SLTozer pointed out offline that you would lose some information when source locations get merged and line numbers replaced with zero; but I imagine that's something you already need to address if you're putting the index in the column number. There are also one or two places where the line-number in `DISubprogram` is used to generate `DILocations`, which again I imagine is something you'd have to deal with anyway.

https://github.com/llvm/llvm-project/pull/201269