Stack overflow

[Michaelc]

Hey
I am havin a problem with stack overflow in MPLAB, i keep getting a stack overflow after 7 or 8 runs of the program. I know i can disable Stack overflow warning for simulation but i need to know what is causing the problem because when i look at the call tree for the program it should'nt be using the full 8 level deep stack for pic16f877 and also My code is crashing out when i program the pic with it, but not after it has at least run once! While simulating i opened the stack window and noticed that calls were getting pushed onto the stack but didn't seem to be getting popped of after returns. Can anyone advise me on why this is so. The function that appears to causes the problem never actually returns, what i do in the function is load the program counter therefore it never returns, is this the problem?? What should i do??

Thanks

[Humberto]

Pls post a piece of code that cause the problem and the compiler version.

Humberto

[Michaelc]

Its actually an operating system iam working on so posting all the relevant code would be impossible, but i have the the code below for a typical task, as you can see its in an infinite loop, below that is the function i think maybe causing the problem again as you can see it never really returns but instead changes the pc.

void outputs()
{


for(;;)
{//printf("out");

OSM_WAIT_BIN(SEM_INPUT, OUT1, OUTPUTS_id);
write_expanded_outputs(current_status);
OSM_YIELD(OUT2 ,OUTPUTS_id);
//The function executes
//from here when it is elegible,
#asm
nop
#endasm

}
}



void OSJump()
{//printf("%x", pRunningTask->return_add_high);
//printf("%x", pRunningTask->return_add_low);
jump_label = pRunningTask->return_add_high ;
#asm
movf jump_label,w
movwf PCLATH
#endasm

jump_label = pRunningTask->return_add_low ;
#asm
movf jump_label,w
movwf PCL
#endasm
return ; //won't actually return because it changes the program counter
}


There is about 3 functions which do similar operations as shown above.

Compiler version is
IDE 2.32
PCM 2.734

Not sure if this will help!
Thanks for the reply!

[Michaelc]

How is the stack popped on the PIC and does loading the pc in a function and not actually returning from the function in the natural way cause the stack not to be popped?

[Ttelmah]

[Humberto]