[Dwarf-discuss] Proposal to encode Changed Function Signatures in dwarf

[Frank Ch. Eigler]

Hi -

> > That sounds like a quality of implementation issue.  Higher quality
> > compilers accurately note the location of parameters, as they change
> > within and after the prologue and other points in the function.  It
> > is a location LIST after all.
> 
> Ish. Certainly it's possible to do that - do you have pointers to any
> compilers that do that? My experience with GCC and Clang at least has been
> that there's (perhaps an undocumented) understanding that the locations are
> only considered to be valid after the prologue/before the epilogue, and so
> it's more efficient in terms of DWARF disk space to only describe that area.

That experience may be dated somewhat. :-) GCC has been doing its best
to produce detailed location lists throughout the function for many
years.  Yeah it bloats location lists.  Try CFLAGS="-g -O2"; look up
the history of CFLAGS=-fvar-tracking-assignments.


- FChE