Hello Jiri,
Thank you for your answer. However, I am not sure about if the casting
is the problem. Casting like (unsigned char)(*(unsigned char *)(long))
should work as long as 'long' can hold full information of pointer.
This is clearly described in ANSI-C standard. Integral type has to hold
value of pointer if size of the integral type is big enough to have the
information.
Beside, if this is a problem, you will see the same problem with other
types, such as char, unsigned char, etc...
Apart of this problem, I found a couple of bugs in my bool implementation.
I'll fix those in cint5.15.38. But, this fix doesn't seem to fix this
problem.
Masaharu Goto
>Date: 06 May 2002 15:13:16 +0200
>From: Jiri Masik <masik@pc203b.fzu.cz>
>To: "Stephen J. Sanders" <ssanders@ku.edu>
>Cc: roottalk@pcroot.cern.ch, cint@pcroot.cern.ch
>Subject: [CINT] Re: [ROOT] root on PPC systems
>
>"Stephen J. Sanders" <ssanders@ku.edu> writes:
>
>> Hi Jiri and Damir,
>> Thanks for the input. It looks like this is a problem that may solve itsel
f
>> with a little patience. If Debian is running gcc 3.0.4 my guess is
>> the other
>> distributions won't be too far behind. In the meantime, I can either
>> avoid the
>> use of booleans or fall back for root 3.02/07, which doesn't have this
>> problem.
>>
>> Regards,
>> Steve
>>
>
>Hi,
>
>unfortunately an upgrade of gcc won't solve this completely. As Damir
>mentioned there's another problem with booleans - the following
>code
>int main(void){
> bool a;
> a=true; printf("%d\n",a);
> a=false; printf("%d\n",a);
> a=true; printf("%d\n",a);
>
> return (0);
>}
>
>prints just 0's on my PPC. It looks like assignment to a bool
>variable works only in the declaration.
>
>I'm trying to find out where the value of a bool is lost.
>It might be related to the lines of cint/src/var.c
>
>#define G__GET_VAR(SIZE,CASTTYPE,CONVFUNC,TYPE,PTYPE) \
>switch(G__var_type) { \
>case 'p': /* return value */ \
> if(var->paran[ig15]<=paran) { \
> /* if(var->varlabel[ig15][paran+1]==0) { */ \
> /* value , an integer */ \
> result.ref = (G__struct_offset+var->p[ig15]+p_inc*SIZE); \
> CONVFUNC(&result,TYPE,(CASTTYPE)(*(CASTTYPE *)(result.ref)));\
> } \
>
>result.ref is a long and for a boolean variable it is called as
>G__GET_VAR(G__INTALLOC ,unsigned char ,G__letint ,'g' ,'G')
>
>so there's a cast like (unsigned char)(*(unsigned char *)(long))
>
>Is this cast guaranteed to work for both little and big endian
>systems? On PPC the function G__letint is called with 0 for result.ref
>being either 1 or 0 as the cast is done on the insignificant byte I
>guess.
>
>cheers
> Jiri
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