Re: [Tinycc-devel] Do not put static variables into a common section.

[Rob Landley]

On Monday 27 August 2007 1:29:32 am Simon 'corecode' Schubert wrote:
> Rob Landley wrote:
> > I'm confused: it looks like (at a quick glance, which is all I'm up for
> > at the moment with this cold) that the patch makes it put the static
> > variables into bss, which is _not_ a common section...?
>
> Exactly.  At least only OS (DragonFly) this is necessary.  Gcc does this on
> Linux as well, so I figured that should at least not be wrong.
>
> I'm no expert in linking, but it occured to me that the common section is
> only for global symbols which in the end get merged to one, i.e. the same
> global symbol defined in multiple objects.  Obviously, this is never the
> case for static symbols:  they all need to be created and may never be
> merged.

Ah, when you said "don't put them in a common section" I parsed that as "put 
each static variable into its own section".

Right, "put static variables in bss, which gcc does and fixes a bug I hit on 
DragonFly" makes much more sense.  (Since a static variable is essentially 
just a global with a weird naming convention, this works fine for me.)

Query: is this just _uninitialized_ static variables?  What happens to ones 
initialized to a default value?  If it's a global, those don't go in .bss, 
they go in...  Darn it, .data?

When in doubt, go back to ancient half-remembered references:
  http://www.linuxjournal.com/article/1059
  http://www.linuxjournal.com/article/1060

> cheers
>   simon

Rob
-- 
"One of my most productive days was throwing away 1000 lines of code."
  - Ken Thompson.