This trace follows the actual state transitions behind the companion What a Function Call Places in a Stack Frame. It describes a common execution path; implementation details can vary, so keep the contract separate from the mechanism.
Step 1: Place arguments per convention
A function call transfers control while preserving enough state for the caller to resume. A calling convention defines how arguments, return values, registers, and stack alignment are handled. A stack frame commonly holds saved registers, local storage, and bookkeeping, though optimizers can keep values in registers or remove frames.
Step 2: Record return and saved state
When function A calls B, the machine records a return location and passes arguments according to the platform ABI. B may reserve stack space and save registers it must preserve. On return, it places the result where the caller expects and restores the control state required by the convention.
Step 3: Create the callee frame
The caller and callee follow an ABI for argument locations and preserved registers; the return path restores enough state for the caller to continue.
At this point, record the state that changed and check the invariant before advancing. If the operation repeats, make clear which values persist and which are recomputed.
Step 4: Execute and produce a result
Recursion creates nested activation state and can exhaust a finite stack. Tail-call elimination can reuse a frame when language and compiler rules permit it, but should not be assumed across every runtime. Stack layout and calling conventions vary by architecture and compiler.
Step 5: Restore caller-visible state
Trace a recursive function with input depth three. At each call, list the values that must remain available for the suspended caller after the deeper call returns.
The trace is complete when the result satisfies the stated contract. Compare this model with the concrete runtime or system you are studying before making a performance claim.