FRAME

From RubySpec

Each level in the call stack gets a FRAME structure allocated to hold information about that call. FRAME contains the following fields:

self

The current "self" object for this method

argc

The count of incoming arguments for the method

argv

The array of arguments for the method (ruby objects)

last_func

The last function called (?)

orig_func

???

last_class

The class under which this method executes (?)

prev

The call chain of FRAME instances is managed as a linked list; prev points at the previous FRAME in the stack

tmp

???

node

The (current? starting?) AST node for Ruby code executing within this frame

iter

The current block-passing state for this frame, see iter

flags

???

uniq

???

extern struct FRAME {
    VALUE self;
    int argc;
    VALUE *argv;
    ID last_func;
    ID orig_func;
    VALUE last_class;
    struct FRAME *prev;
    struct FRAME *tmp;
    struct RNode *node;
    int iter;
    int flags;
    unsigned long uniq;
} *ruby_frame;