marCsweep/include/vm.h

#ifndef VM_H
#define VM_H

#define STACK_MAX 1024
#define GC_THRESHOLD 256

// Primitive types for garbage collection
enum garbageData {
	GARBAGE_INT,
	GARBAGE_PAIR,
};

// Holds type and value data for the virtual machine
struct garbageObject {
	enum garbageData type;
	struct garbageObject *next;
	unsigned char mark;

	union {
		int value;

		struct {
			struct garbageObject *head;
			struct garbageObject *tail;
		};
	};
};

// Virtual machine hold the stack to trace references
struct virtualMachine {
	int stackSize;
	unsigned refCount;
	unsigned refMax;
	struct garbageObject *head;
	struct garbageObject *stack[STACK_MAX];
};

// Create a new garbageObject
struct garbageObject *initGarbage(struct virtualMachine *vm,
				  enum garbageData type);

// Create a new VM
struct virtualMachine *initVM(void);

void deinitVM(struct virtualMachine *vm);

// Generic function to push data onto the VM stack
void push(struct virtualMachine *vm, struct garbageObject *value);

// Pop data from the VM stack
struct garbageObject *pop(struct virtualMachine *vm);

// Push a GARBAGE_INT onto the VM stack
void pushInt(struct virtualMachine *vm, int value);

// Push a GARBAGE_PAIR onto the VM stack
struct garbageObject *pushPair(struct virtualMachine *vm);

#endif /* VM_H */