topic Re: disable "Removed dead code" in S12 / MagniV Microcontrollers

disable "Removed dead code"

nic_mcp — Mon, 10 Dec 2007 18:19:45 GMT

Hi guys,

how can i force CodeWarrior to disabling the removal of dead code?

I'm using the DEMO9S12XDT512 (HCS12) and i must disable this feature!
I read about #pragma implementation, but i don't know which pragma it is for the HCS12!

thx

nic

Re: disable "Removed dead code"

CompilerGuru — Mon, 10 Dec 2007 22:31:21 GMT

What kind of "dead code" do you want to keep?
Code inside of a function which never gets executed (that's what I would call dead code)?
Or functions or other objects which do not get linked because they are not referenced?
Normally dead code inside of a function is dead, and I don't really see any reason to ever keep it, there are options in the compiler for that tought, I think.
But normally the question is asked with the idea of unreferences objects and for that case check the linker manual, more precisly the ENTRIES keywords.
Basically in the prm file, list all the additional objects in a ENTRIES name0 name1 END block.

Daniel

Re: disable "Removed dead code"

Ricardo_RauppV — Mon, 20 Apr 2009 23:51:05 GMT

Daniel

I have several functions wich in fact are accessed only through pointer to function.

I use it to state machine control.

CW considered these functions as NOT USED, and so my pointer has allways 0x0000.

I´m using CW6.0 Pro , C++.

How can I tell CW to keep these function active, that is, they are really needed although there is not a explicit call...

Use ENTRIES? for each function? for Claases?

Is tehere a global way to make it works, like a checkbox like:

( ) Don´t discard not used objects.

Thanks in advance !!

Ricardo Raupp

Re: disable "Removed dead code"

Ricardo_RauppV — Tue, 21 Apr 2009 00:24:03 GMT

Daniel

Meanwhile the post before I made:

ENTRIES
lcd_char_drv.cpp.o:*
keyboard_drv.cpp.o:*
buzzer_drv.cpp.o:*
gpio_drv.cpp.o:*
END

and all of my not referenced functions are now allocated in a specific address...

It seems nice..not hard taks, since the whole file can be added into list and not function by function as I thought...

Is it ok?Some side effect?

Thanks

Ricardo Raupp

Re: disable "Removed dead code"

CompilerGuru — Tue, 21 Apr 2009 02:51:48 GMT

Usages through pointer to functions should be considered too as long as the function pointer on its own is referenced.

Where do you see "and so my pointer has allways 0x0000."?

In the map file or in a target data structure?

Daniel

Re: disable "Removed dead code"

Ricardo_RauppV — Tue, 21 Apr 2009 03:07:36 GMT

Daniel

As I mentioned before, now my functions are allocated on ROM.Ican see their address in the map files.

Before the use of ENTRIES , none of them was there, unless in the NOT USED list...

In the constructor below I tried to catch the address of one function, but it is returning 0x00...

// general pointer4 to function declaration
typedef uint8 (*state_handler_t)(void*,Event const*)

Keyboard::Keyboard():
// Super_class constructor
Active_object((state_handler_t)&Keyboard:n_initial), // default state!!!
// timer(s) object(s) constructor(s)
main_timer(EVENT_KEYBOARD_MAIN_TIMER_TIMEOUT)
{
state_handler_t far a;
state_handler_t far d;
uint16 b;
uint8 c;

c=Keyboard:n_initial(this); // it really runs on_initial() function...
b=(uint16)&Keyboard:n_initial; // this result is zero.. ???
a=(state_handler_t)&(Keyboard:n_ready); // this result is zero.. ???
d=(state_handler_t)&(Keyboard:n_initial);// this result is zero.. ???
// dummy ...
if(a)
{
b++;
}

}

}

The map file shows:

Name Addr hSize dSize Ref Section RLIB

on_initial__8KeyboardFP8Keyboard 3254 15 21 1 .text
on_ready__8KeyboardFP8KeyboardPC5Event 3269 10 16 0 .text

The function is:

//
uint8 Keyboard:n_initial(Keyboard *me)
{
(void)me;
return FSM_NEW_STATE_HANDLER(&Keyboard:n_ready);
}

It is clean for you?

Very thanks for your attention Daniel ...

Re: disable "Removed dead code"

Ricardo_RauppV — Tue, 21 Apr 2009 04:34:18 GMT

Daniel

Attached a screenshot (JPG) of IDE..

It helps?

Ricardo

Re: disable "Removed dead code"

CompilerGuru — Tue, 21 Apr 2009 09:37:07 GMT

Strange, the first thing which comes to my mind is that the a,b,c, d locals are all unused local variables.

Therefore I wonder if the compiler did not just remove those variables.

Does it change anything if the code actually uses those variables (without ENTRIES) or with ENTRIES, are the seen values different? (without any other changes).

Which addresses does the debugger show when selecting a,b,c,d?

Daniel

Re: disable "Removed dead code"

Ricardo_RauppV — Wed, 22 Apr 2009 23:53:53 GMT

Daniel

I think this question I solved now ...

I got the right address of those functions AFTER I add "static" in fornt of its declaration in the class.

About those variables a,b,c,d....they worked perfectly after I change the functions to static....

I undesrtood that that only static function can have its address "captured/read" by a var,pointer..whatever....

Is this understanding right?

If yes..so it is finished...

Thanks Daniel ...

Ricardo Raupp