Re: [avr-gcc-list] Allocation sequence of eeprom variables

[Juergen Harms]

On 08/20/2012 10:10 PM, David Brown wrote:
> Almost certainly, there is something wrong in your code, or in the way
> you have declared your external data - the "-Wuninitialized" flag should
> not give false positives as you describe.  (It can give false positives,
> when you know yourself that all code paths that use the data have
> initialised the variables but the compiler is unable to prove this.)

I got rid of most of the "-Wuninitialized" warnings by introducing 
intermediate typedefs - for instance, replacing

extern  const double    sunrise_fact[] PROGMEM;
   by
typedef double PROGMEM          prog_double;
extern  const prog_double       *sunrise_fact;


One single warning remains that I did not manage to suppress:

extern  const prog_int8_t max_module;

What is wrong with that? max_module is defined in another module and is 
initialised to a very constant value. The warning message is given when 
VersionPanel.c is compiled

VersionPanel.c: In function 'ShowCpuInfo':
VersionPanel.c:71:26: warning: uninitialized variable 'max_module' put 
into program memory area [-Wuninitialized]

and the reference to max_module in ShowCpuInfo is:

    if ( x_value <= pgm_read_byte ( &max_module ) ) {

Any suggestions how to avoid this last warning - would be great if I get 
back to a make listing without warnings.