c memory layout

c memory layout

c memory layout

c memory layout

c memory layout

types of memory in c

types of memory in c

types of memory in c

types of memory in c

types of memory in c

types of memory in c

types of memory in c

c memory layout

stack

stack

consider the following code:

int foo( int count, double d)
{
}

stack

consider the following code:

int foo( int count, double d)
{
    int total = 0 ;

    for (unsigned int i = 0 ; i < count ; ++ i)
        ++total ;

    return total ;
}

stack

consider the following code:

int foo( int count, double d)
{
    int total = 0 ;

    for (unsigned int i = 0 ; i < count ; ++ i)
        ++total ;

    return total ;
}

int main()
{
    foo() ;
    return 0 ;
}

what happens when main() calls foo()?

what happens when main() calls foo()?

what happens when main() calls foo()?

what happens when main() calls foo()?

what happens when main() calls foo()?

what happens when main() calls foo()?

stack

now consider another function bar():

void bar( char c[] )
{
    int x ;
    char* pc = c ;
}

int foo( int count, double d)
{
    int total = 0 ;

    for (unsigned int i = 0 ; i < count ; ++ i)
        ++total ;

    return total ;
}

stack

foo() calls bar():

void bar( char c[] )
{
    int x ;
    char* pc = c ;
}
int foo( int count, double d)
{
    int total = 0 ;
    for (unsigned int i = 0 ; i < count ; ++ i)
        ++total ;

    char* pc = "hello!" ;
    bar(pc) ;

    return total ;
}

what happens when foo() calls bar()?

what happens when foo() calls bar()?

• foo()'s SF/AR is already on the stack

what happens when foo() calls bar()?

• foo()'s SF/AR is already on the stack
• now bar()'s SF/AR must be created

bar()'s activation record is created!

bar()'s activation record is created!

bar()'s activation record is created!

bar()'s activation record is created!