1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
#ifndef BDL_VM_H
#define BDL_VM_H
#include "types.h"
#include "errors.h"
#include "chunk.h"
#include "ops.h"
#include "debug.h"
#define VM_STACK_CAP 1024
typedef struct VM {
// Program code.
Chunk *chunk;
// Program counter.
u8 *pc;
// Stack.
Object *stack;
} VM;
void vm_init(VM *vm);
void vm_free(VM *vm);
void vm_reset(VM *vm);
void vm_interpret(VM *vm, Chunk *chunk);
void
vm_init(VM *vm) {
*vm = (VM){0};
array_init(vm->stack, VM_STACK_CAP);
}
void
vm_free(VM *vm) {
array_free(vm->stack);
}
void
vm_reset(VM *vm) {
vm_free(vm);
vm_init(vm);
}
// Helper macros for a more clear VM switch.
#define FIXNUM_BINARY_OP(OP) \
do { \
Object a = array_pop(vm->stack); \
Object b = array_pop(vm->stack); \
if (!IS_FIXNUM(a) || !IS_FIXNUM(b)) { \
error_push((Error){ \
.type = ERR_TYPE_RUNTIME, \
.value = ERR_WRONG_ARG_TYPE, \
.line = vm->chunk->lines[vm->pc - vm->chunk->code - 1].line, \
.col = vm->chunk->lines[vm->pc - vm->chunk->code - 1].col, \
}); \
return; \
} \
ssize_t x = AS_FIXNUM(a); \
ssize_t y = AS_FIXNUM(b); \
array_push(vm->stack, FIXNUM_VAL(y OP x)); \
} while (false)
#define FIXNUM_CMP_OP(OP) \
do { \
Object a = array_pop(vm->stack); \
Object b = array_pop(vm->stack); \
if (!IS_FIXNUM(a) || !IS_FIXNUM(b)) { \
error_push((Error){ \
.type = ERR_TYPE_RUNTIME, \
.value = ERR_WRONG_ARG_TYPE, \
.line = vm->chunk->lines[vm->pc - vm->chunk->code - 1].line, \
.col = vm->chunk->lines[vm->pc - vm->chunk->code - 1].col, \
}); \
return; \
} \
ssize_t x = AS_FIXNUM(a); \
ssize_t y = AS_FIXNUM(b); \
Object result = y OP x ? TRUE_VAL : FALSE_VAL; \
array_push(vm->stack, result); \
} while (false)
#define LOGIC_OP(OP) \
do { \
Object a = array_pop(vm->stack); \
Object b = array_pop(vm->stack); \
bool x = IS_TRUE(a); \
bool y = IS_TRUE(b); \
Object result = y OP x ? TRUE_VAL : FALSE_VAL; \
array_push(vm->stack, result); \
} while (false)
void
vm_interpret(VM *vm, Chunk *chunk) {
vm->chunk = chunk;
vm->pc = vm->chunk->code;
if (vm->chunk->code == NULL || array_size(vm->chunk->code) == 0) {
error_push((Error){
.type = ERR_TYPE_RUNTIME,
.value = ERR_EMPTY_CHUNK,
});
return;
}
u8 *last = vm->chunk->code + array_size(vm->chunk->code);
while (vm->pc < last) {
#ifdef DEBUG_TRACE_EXECUTION
printf("stack: [ ");
for (size_t i = 0; i < array_size(vm->stack); i++) {
display(vm->stack[i]);
if (i < array_size(vm->stack) - 1) {
printf(" | ");
}
}
printf(" ]\nop: ");
disassemble_instruction(vm->chunk, (vm->pc - vm->chunk->code));
#endif
u8 instruction = *vm->pc++;
switch (instruction) {
case OP_CONSTANT: {
u8 constant = *vm->pc++;
Object obj = vm->chunk->constants[constant];
array_push(vm->stack, obj);
} break;
case OP_SUM: { FIXNUM_BINARY_OP(+); } break;
case OP_SUB: { FIXNUM_BINARY_OP(-); } break;
case OP_MUL: { FIXNUM_BINARY_OP(*); } break;
case OP_DIV: { FIXNUM_BINARY_OP(/); } break;
case OP_MOD: { FIXNUM_BINARY_OP(%); } break;
case OP_NOT: {
Object prev = array_pop(vm->stack);
Object new = IS_TRUE(prev) ? FALSE_VAL : TRUE_VAL;
array_push(vm->stack, new);
} break;
case OP_AND: { LOGIC_OP(&&); } break;
case OP_OR: { LOGIC_OP(||); } break;
case OP_EQUAL: { FIXNUM_CMP_OP(==); } break;
case OP_LESS: { FIXNUM_CMP_OP(<); } break;
case OP_GREATER: { FIXNUM_CMP_OP(>); } break;
case OP_LESS_EQUAL: { FIXNUM_CMP_OP(<=); } break;
case OP_GREATER_EQUAL: { FIXNUM_CMP_OP(>=); } break;
case OP_RETURN: {
display(array_pop(vm->stack));
printf("\n");
return;
} break;
default: {
error_push((Error){
.type = ERR_TYPE_RUNTIME,
.value = ERR_NOT_IMPLEMENTED,
.line = vm->chunk->lines[vm->pc - vm->chunk->code - 1].line,
.col = vm->chunk->lines[vm->pc - vm->chunk->code - 1].col,
});
return;
} break;
}
}
error_push((Error){
.type = ERR_TYPE_RUNTIME,
.value = ERR_PC_OOB,
.line = vm->chunk->lines[0].line,
.col = vm->chunk->lines[0].col,
});
}
#undef FIXNUM_BINARY_OP
#undef FIXNUM_CMP_OP
#undef LOGIC_OP
#endif // BDL_VM_H
|
