[PATCH] [RFC] Rewrite the way we generate debug locations for variables.

[Adrian Prantl]

On Jan 30, 2014, at 12:07, Alexey Samsonov <samsonov at google.com> wrote:
> 
>    BB1:
>      DBG_VALUE: var "x" is in %rax
>      jmp BB3
>    BB2:
>      DBG_VALUE: var "x" is in %rbx
>      jmp BB3
>    BB3:
>      // what DBG_VALUE for "x" should we insert here?

This is a great example, showing why we really want to extend the ranges instead. The interesting bit here is that we would want to have two overlapping location ranges:
  BB1, BB3 var “x" is in $rax
  BB2, BB3 var “x" is in $rbx
and incidentally the DWARF spec says that: "Address ranges defined by normal location list entries may overlap.”
I wonder if debuggers can deal with this, though.

thanks,
Adrian