Re: Building unwind tables by default

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Mon, Jun 10, 2013 at 11:30:18PM +0200, Martin Husemann wrote:
> Can you explain a bit of background?

The unwind tables essentially describe the stack layout of functions,
e.g. where registers are saved, what register is used to address the
local frame and how to call destructors in case of C++.

> Is there a compiler option to enable it unwind tables at (compiler) runtime?
> Or an option to disable them?

-funwind-tables / -fno-unwind-tables.

> If yes, it should be solved at the makefile level. If not, we should add
> this option ;-)

The option for space constrained code is to either selectively disable
it or to just strip them like crunchgen now does. The advantage of the
latter is that it also works for assembler sources. We currently don't
have the necessary attributions, but that's a separate bug which should
slowly be fixed.

> Or is there any good reason to hardcode it in the compiler?

Consistent results. Quite important if you want to use backtrace.

Joerg