Stack underflow

Hi, I'm trying to get some insight on what could be causing a stack underflow error. I have some code that looks like

Code:

---

void * func1(a_struct s)
{

 .....

 printf("s = 0x%p.\n", s);
 printf("&s = 0x%p.\n", &s);

 foo = func2(s);

 .....

 return foo;
}

void * func2(a_struct s)
{
 printf("s = 0x%p.\n", s);
 printf("&s = 0x%p.\n", &s);

 ......

return foo;
}

---

func1 prints out 's' just fine but in func2 I get a stack underflow when trying to print s or &s. I can tell it's an underflow from looking at the assembly. A store instruction is getting called to store a register val just before the start of the stack. This happens with any kind of reference to 's' in func2.

Anyone have any idea what could be going on?

You've removed any code that could be affecting the values.

You need to post exact code which produces the problem (not something full of .... which has in all likelyhood snipped the problem).

You also need to say which OS/Compiler you're using, and be specific (not something vague like Microsoft/Microsoft)

Code:

---

printf("s = 0x%p.\n", s);
printf("&s = 0x%p.\n", &s);

---

%p expects a void*, but you pass it a struct and a pointer to struct. the pointer to struct might not cause problems (but use (void*)&s just to be sure), but the struct probably would. the variable arguments might be being pushed onto the stack and then maybe the stack's getting messed up because printf doesn't know what's passed to it. guessing.

Well since they cut out all useful code a_struct could very well be a void * :D

yeah, but then &s would be a void** :)