RE: [avr-libc-dev] PROGMEM section variables throw away by--gc-sections?

[Weddington, Eric]

> -----Original Message-----
> From: 
> address@hidden 
> [mailto:address@hidden
> org] On Behalf Of Dean
> Sent: Tuesday, November 13, 2007 5:59 PM
> To: address@hidden
> Subject: [avr-libc-dev] PROGMEM section variables throw away 
> by--gc-sections?
> 
> Hi guys,
> 
> I've been noticing some strange behaviour with my makefile arguments.
> 
> Firstly, LD.exe crashes when I use -mshort-calls with the 
> --relax linker option, but *only* if I *don't* use 
> -ffunction-sections and --gc-sections. With the latter two 
> options enabled both -mshort-calls and --relax work just fine.

IIRC, this was discussed somewhat on Freaks, although you seem to have
found a new twist on the matter. ;-) Can you open up a binutils bug
report? Let me know what the bug number is.

 
> Secondly, -ffunction-sections and --gc-sections seems to 
> throw away some of my PROGMEM variables. I rely on a few 
> PROGMEM variables being embedded into the binary so I can 
> later distinguish which version it was compiled from, similar to:
> 
> char PROGMEM buildtime[] = __TIME__;
> 
> --gc-sections seems to remove this, although I thought it was 
> only designed to remove unused functions and not PROGMEM 
> data. Is there a workaround to this?
> 

Can you post a minimal test case? What versions of the tools are you
using?

Thanks,
Eric Weddington