bread/vm.h at master · ss7m/bread · GitHub

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#ifndef BRD_VM_H
#define BRD_VM_H

/* stack is limited to 256 values */
#define STACK_SIZE 256

/* number of frames is limited to 64 */
/* so you can only do recursion 64 calls deep */
#define FRAME_SIZE 64

#define INITIAL_THRESHOLD 100

/* VM bytecode */
/* Stack based virtual machine */

typedef char brd_bytecode_t;

enum brd_bytecode {
        BRD_VM_NUM, /* has arg: long double */
        BRD_VM_STR, /* has arg: string */
        BRD_VM_GET_VAR, /* has arg: string */
        BRD_VM_TRUE,
        BRD_VM_FALSE,
        BRD_VM_UNIT,

        /* arithmetic */
        BRD_VM_PLUS,
        BRD_VM_MINUS,
        BRD_VM_MUL,
        BRD_VM_DIV,
        BRD_VM_IDIV,
        BRD_VM_MOD,
        BRD_VM_POW,
        BRD_VM_NEGATE,

        /* comp */
        BRD_VM_LT,
        BRD_VM_LEQ,
        BRD_VM_GT,
        BRD_VM_GEQ,
        BRD_VM_EQ,

        BRD_VM_CONCAT,

        /* boolean */
        BRD_VM_NOT,
        BRD_VM_TEST,  /* if peek()     then pop(); pc++ */
        BRD_VM_TESTN, /* if not peek() then pop(); pc++*/
        BRD_VM_TESTP, /* if pop()      then pc++ */
        /* these three instructions are ALWAYS to be followed by a JMP instruction */

        BRD_VM_SET_VAR, /* has arg: string */
        BRD_VM_BUILTIN, /* has arg: size_t */
        BRD_VM_CALL, /* has arg: size_t */
        BRD_VM_CLOSURE, /* has args size_t, strings, bytecode, followed by a JMP */
        BRD_VM_JMP, /* has arg: size_t */
        BRD_VM_JMPB, /* has arg: size_t */

        /* this will do more when we have functions and classes */
        BRD_VM_RETURN,
        BRD_VM_POP,

        BRD_VM_GET_IDX,
        BRD_VM_SET_IDX,

        BRD_VM_GET_FIELD,
        BRD_VM_SET_FIELD,

        BRD_VM_SUBCLASS,
        BRD_VM_SET_CLASS,

        BRD_VM_ACC_OBJ,

        BRD_VM_LIST, /* initializes an empty list */
        /* this is poorly named, it's a list operation */
        BRD_VM_PUSH, /* x = pop(), peek().push(x) */
        BRD_VM_PUSH_DICT,
};

struct brd_stack {
        struct brd_value values[STACK_SIZE];
        struct brd_value *sp;
        char _p[8];
};

struct brd_frame {
        size_t pc;
        struct brd_value_map globals, locals;
};

struct brd_string_constant_list {
        struct brd_string_constant_list *next;
        struct brd_value_string string;
};

struct brd_vm {
        struct brd_stack stack;
        struct brd_heap_entry *heap;
        struct brd_string_constant_list *strings;
        brd_bytecode_t *bytecode;
        size_t bc_length, bc_capacity;
        size_t fp;
        struct brd_frame frame[FRAME_SIZE];
        unsigned int threshold, heap_size;
        char _p[8];
};

extern struct brd_vm vm;

void brd_stack_push(struct brd_stack *stack, struct brd_value *value);
struct brd_value *brd_stack_pop(struct brd_stack *stack);
struct brd_value *brd_stack_peek(struct brd_stack *stack);

void brd_node_compile(struct brd_node *node);

void brd_vm_destroy(void);
void brd_vm_init(void);
void brd_vm_allocate(struct brd_heap_entry *entry);
struct brd_string_constant_list *brd_vm_add_string_constant(char *string);
void brd_vm_run(void);

void brd_vm_gc(void);
#endif