Stackframe

Stack frame, also called activation frame or call frame, is a data structure used by a program to manage information associated with a subroutine invocation on a call stack. Each function call creates a new frame that holds the state needed to transfer control back to the caller, to pass parameters, and to store results and local data. In some managed environments, a StackFrame may refer to an API object representing a single frame and exposing debugging metadata.

Typical contents include the return address, the saved frame pointer, space for local variables, storage for function parameters, and saved callee-saved registers. The frame layout is guided by the platform’s calling convention. In many architectures the stack grows downward; a prologue sets up the frame and saves registers, while an epilogue restores registers and returns, popping the frame off the stack. Frame pointers may be used to provide a fixed reference into the frame, though some optimizing compilers omit them.

Uses and implications of stack frames include enabling debugging and exception handling through stack unwinding and stack traces. In managed runtimes, frames may be represented synthetically for the interpreter or just-in-time compiler and used for garbage collection and debugging metadata. Frames are central to recursion and non-tail calls; in tail-call optimized code the current frame may be reused or eliminated, reducing stack depth. Stack frames also influence crash analysis and security, as stack traces reveal the call sequence at the point of failure.