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Visual C++ Function Address
Posted: Fri Apr 24, 2009 6:26 pm
by InsightSoft
Hi,
I have this problem:
1--- the declaration
2--- the values
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void _cls_irq::InstallHandler(int irq, void (*handler)(tpRegistersStructure *))
{
irq_routines[irq] = (void *)handler;
}
and
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void handler_Timer(tpRegistersStructure *r)
{
blablabla
}
then
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IRQ.InstallHandler(0, handler_Timer); //get handler_timer function address and put on irq_routines[0]
3----- the problem (for every irq)
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void handler_IRQ(tpRegistersStructure *r)
{
void (*handler)(tpRegistersStructure *r); //pointer for incoming function with this format -> return (void *) and
//get (tpRegistersStructure *r) as parameters
handler = irq_routines[(r->int_no - 32)]; //with this index, get its correspondent function address
(this does not run!!!!!!!!!!!!!!!!!! -> Can you tel me why???
this simple example just works fine:
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void (*p)(int i);
p = myfunction;
(*p)(23); // call myfunction with 23 as parameter
[ JamesM: Added code tags. ]
Re: Visual C++ Function Address
Posted: Fri Apr 24, 2009 6:29 pm
by pcmattman
Firstly, please use code tags - they make it far easier to read your post!
Code: Select all
handler = irq_routines[(r->int_no - 32)]; //with this index, get its correspondent function address
Do you actually ever call the function?
Re: Visual C++ Function Address
Posted: Fri Apr 24, 2009 6:32 pm
by InsightSoft
Yap...
Code: Select all
void handler_IRQ(tpRegistersStructure *r)
{
void (*handler)(tpRegistersStructure *r);
handler = irq_routines[(r->int_no - 32)]; //to discover in matrix that start from 0 index
if(handler)
{
handler(r); //execute this address
}
if(r->int_no >= 40)
{
Ports.SendByte(0xA0, 0x20);
}
Ports.SendByte(0x20, 0x20);
}
Re: Visual C++ Function Address
Posted: Fri Apr 24, 2009 6:33 pm
by InsightSoft
The result is:
error C2440: '=' : cannot convert from 'void *' to 'void (__cdecl *)(tpRegistersStructure *)'
Re: Visual C++ Function Address
Posted: Fri Apr 24, 2009 6:36 pm
by pcmattman
Okay, that's because you've defined irq_handlers as:
Yet you want to use it as a:
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void (*handler)(tpRegistersStructure *)
You either need to use a cast when obtaining the IRQ handler from the array, or you need to typedef the handler function pointer type and use that instead of void*.
Re: Visual C++ Function Address
Posted: Sat Apr 25, 2009 5:32 am
by JamesM
Hi,
Firstly, you didn't mention if the IRQ handler gets called at all - you only mentioned the IRQ dispatch afterwards. Does the function IRQ_Handler get called when an IRQ comes in?
If not, which is what I suspect, have you remapped the PIC? Have you enabled interrupts?
Cheers,
James
Re: Visual C++ Function Address
Posted: Sat Apr 25, 2009 5:51 am
by InsightSoft
Yap...
...remember: that error is at compilation stage...
Re: Visual C++ Function Address
Posted: Sat Apr 25, 2009 6:15 am
by pcmattman
And I told you how to fix the compilation error. Read my post for the answer
Re: Visual C++ Function Address
Posted: Sat Apr 25, 2009 6:20 am
by InsightSoft
Ya... I know... its what I am trying to do
Re: Visual C++ Function Address
Posted: Sat Apr 25, 2009 8:17 am
by InsightSoft
pcmattman wrote:Okay, that's because you've defined irq_handlers as:
Yet you want to use it as a:
Code: Select all
void (*handler)(tpRegistersStructure *)
You either need to use a cast when obtaining the IRQ handler from the array, or you need to typedef the handler function pointer type and use that instead of void*.
And how to do that? can you help me?
Re: Visual C++ Function Address
Posted: Sat Apr 25, 2009 1:02 pm
by Creature
Gah.. Please know your function pointers before you use them:
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typedef void (*FunctionPointerType)(tpRegistersStructure *);
FunctionPointerType ArrayOfFunctionPointers[16];
Now you (should) have an array of function pointers which point to a function with 'void' as return type and 1 argument, namely a 'tpRegistersStructure' pointer.
Re: Visual C++ Function Address
Posted: Sun Apr 26, 2009 2:49 am
by JamesM
Re: Visual C++ Function Address
Posted: Sun Apr 26, 2009 3:21 am
by DeletedAccount
Hi,
This a a general 'C' question and has nothing to do with VC++ compiler . Bad topic
Regards
Shrek
