llvm dev - Apr 2021 - Tracking all prologue and epilogue insertions through codegen/lowering

> I’m doing some program analysis research within LLVM. One thing that I’d
like to be able to
> do is track LLVM’s generation of function prologues and epilogues

Answering my own question with this: I managed to completely overlook the fact
that DWARF (since at least v3) has supported fields within the line program
state
machine that explicitly record whether a particular entry indicates a prologue
end
(DW_LNS_set_prologue_end) and epilogue begin (DW_LNS_set_epilogue_begin).

- William

> > I’m doing some program analysis research within LLVM. One thing that
I’d
> like to be able to
> > do is track LLVM’s generation of function prologues and epilogues
> 
> 
> Answering my own question with this: I managed to completely overlook the
> fact
> that DWARF (since at least v3) has supported fields within the line
> program state
> machine that explicitly record whether a particular entry indicates a
> prologue end
> (DW_LNS_set_prologue_end) and epilogue begin (DW_LNS_set_epilogue_begin).
Well, yes, DWARF has that.  LLVM does not do a spectacular job of
identifying those points, although it has been getting better at it
over the years.
--paulr