Question

I’m reading Thinking in C++ (vol. 2):

Whenever a function is called,
information about that function is
pushed onto the runtime stack in an
activation record instance (ARI), also
called a stack frame. A typical stack
frame contains (1) the address of the
calling function (so execution can
return to it), (2) a pointer to the ARI of
the function’s static parent (the
scope that lexically contains the
called function, so variables global
to the function can be accessed), and
(3) a pointer to the function that called
it (its dynamic parent). The path that
logically results from repetitively
following the dynamic parent links is
the dynamic chain, or call chain

I’m unable to comprehend what the author means as function’s static and dynamic parent. Also am not able to differentiate between item 1, 2 or 3. They all seem to be the same. Can someone please explain this passage to me?

Answer 1

This all sounds very odd to me. Static frame pointers are normally used in languages with lexical scope, such as functional languages, and the pascal family with their nested functions. Globals are bound once either at compile time or runtime, and shouldn’t need frame pointers. (1) is valid, but (2) doesn’t exist in C++, AFAIK.

I suspect that (3) was meant to refer to the parent frame pointer. Call stacks are usually setup as linked lists so that debuggers and related tools can walk them without requiring deep knowledge of the program.