Re: extern variable

[sumanth <sumanth.gundapneni@redpinesignals.com>]

Jim,
      If I  define USER_LABEL_PREFIX "" and declare a global variable 
using names r0/r1...r15 ( my register names ) , my assembler is 
generating an error message saying " r0 is already defined , cannot use 
register in expression " ........

       How can i make sure my tool chain knows the difference between 
global variable r0 and register r0.

Regards,
Sumanth G
      

Jim Wilson wrote:
> On 07/30/2009 07:38 AM, sumanth wrote:
>> How can I make sure the debugging information printed by my compiler for
>> extern variables is correct.
>> I am able to print them in gdb in with an _ (underscore). I am using
>> Gcc-4.3.4 and gdb 5.3
>
> ELF targets usually don't prepend an underscore to symbol names.  But 
> if you are prepending an underscore for some reason, then you need to 
> make sure that your ASM_OUTPUT_* macros handle this correctly.  You 
> set USER_LABEL_PREFIX to an underscore, and then you add the 
> USER_LABEL_PREFIX unless the symbol name starts with '*'.  See the 
> ASM_GENERATE_INTERNAL_LABEL docs.  This stuff can be tricky.  You will 
> probably have to step through your cc1 port in gdb to see exactly what 
> is going on.  It will be useful to look at an existing port that 
> handles this correctly; step through it in gdb to see how it works.
>
> Jim
>
>