Re: [avr-gcc-list] strange c++ obiect initialization problems (full code included)

[Marcin S]

2011/6/9 Georg-Johann Lay <address@hidden>:
> Marcin S schrieb:
>> Hello there,
>>
>> from time to time i have a strange problems when initializing class
>> objects in file range by their respective constructors, i noted that
>> problem occurs only when that constructors takes pointers to other
>> global objects, tables or something else.
>>
>> Whats the problem? in best scenario object pointer are wrongly set and
>> pointing to some random locations, at worst my program does not start
>> at all (event with my main() func empty) it just hangs
>>
>> here is link to my code
>> http://dl.dropbox.com/u/6883398/Lays.tar.bz2
>> its and eclipse project, simple "make" in project directory should
>> work too. Note that archive contains already compiled program in
>> "Release" directory, this compilation does not work at all! (worst
>> case scenario described above).
>>
>> As I wrote this program incrementaly it stopped working after i added
>> 2 objects inits in layouts.cpp
>>
>>         CLayPGMString minTag(minTagData,strMin,true,CLayPGMString::XSMALL);
>>       CLayPGMString maxTag(maxTagData,strMax,true,CLayPGMString::XSMALL);
>>
>> strMin and strMax params are pointers to strings in PROGMEM, if i
>> replace it with zeros like
>>
>>         CLayPGMString minTag(minTagData,0,true,CLayPGMString::XSMALL);
>>       CLayPGMString maxTag(maxTagData,0,true,CLayPGMString::XSMALL);
>>
>> program starts again.
>>
>> Other important thing noted is, when I initialise those objects in
>> file range with their default, empty constructors and then set needed
>> pointers at run time (for example right after main() function)
>> everything works too.
>> I ran out of ideas what could be wrong, maybe wrong code, I'm open to
>> any suggestions.
>>
>> I'm using avr-gcc-4.5.2 on gentoo linux, also checked on stable 4.4
>> and it behaves exactly the same way.
>>
>> Marcin
>
> Do you see r20 used in one of the functions? Reminds me of
> http://gcc.gnu.org/PR45263
> which is not yet backported to avr-gcc < 4.6
>
> Johann
>
>
>

Hej Johann,

I'm not sure if i checked it correctly, I've opened .lss file
corresponding to my program and yes, there are some r20 operations in
this function.

Excuse me my lack of knowledge of low lvl stuff, but You think this
might cause the problem?

Marcin