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#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdio.h>
#include "val.h"
#include "vm.h"
#include "dis.h"
void *M(void *p, size_t sz) {
if (sz == 0) {
free(p);
return NULL;
} else {
return realloc(p, sz);
}
}
Chunk chunk_new() {
return (Chunk){
.blen = 0, .bcap = 0, .b = NULL,
.clen = 0, .ccap = 0, .c = NULL,
};
}
size_t chunk_wbc(Chunk *ch, uint8_t byte) {
if (ch->blen == ch->bcap) {
size_t newsz = (ch->bcap == 0 ? 8 : ch->bcap * 2);
ch->b = M(ch->b, newsz * sizeof(uint8_t));
ch->bcap = newsz;
}
size_t ix = ch->blen;
ch->b[ix] = byte;
ch->blen ++;
return ix;
}
size_t chunk_wconst(Chunk *ch, Val v) {
if (ch->clen == ch->ccap) {
size_t newsz = (ch->ccap == 0 ? 8 : ch->ccap *2);
ch->c = M(ch->c, newsz * sizeof(Val));
ch->ccap = newsz;
}
size_t ix = ch->clen;
ch->c[ix] = v;
ch->clen ++;
return ix;
}
Vm vm_new(Chunk *ch) {
Vm vm = (Vm){
.ch = ch,
.ip = 0,
.sp = 0
};
for (int i = 0; i < STACKSIZE; i++) {
vm.stack[i] = VAL_NIL;
}
return vm;
}
static void runvm() {
Chunk ch = chunk_new();
chunk_wbc(&ch, OP_LOADK);
chunk_wbc(&ch, chunk_wconst(&ch, VAL_NUM(10.0)));
chunk_wbc(&ch, OP_LOADK);
chunk_wbc(&ch, chunk_wconst(&ch, VAL_NUM(3.0)));
chunk_wbc(&ch, OP_DIV);
chunk_wbc(&ch, OP_PRINT);
chunk_wbc(&ch, OP_RET);
disasm_chunk(&ch);
Vm vm = vm_new(&ch);
#define RBYTE() (vm.ch->b[vm.ip++])
#define PUSH(v) vm.stack[vm.sp++] = v;
#define POP() (vm.stack[--vm.sp])
puts("---");
while (1) {
uint8_t instr = RBYTE();
switch (instr) {
case OP_RET:
printf("done!\n");
goto done;
break;
case OP_LOADK:;
uint8_t cix = RBYTE();
Val v = vm.ch->c[cix];
PUSH(v);
// printf(" (pushing ");
// print_val(v);
// printf(")\n");
break;
case OP_PRINT:
println_val(POP());
break;
#define ARITH_OP(opcode, OP) \
case opcode: { \
Val b = POP(); \
Val a = POP(); \
if (!IS_NUM(a) || !IS_NUM(b)) { \
printf("can't do arithmetic on %s and %s\n", \
valty_str(a.ty), valty_str(b.ty)); \
goto done; \
} \
PUSH(VAL_NUM(AS_NUM(a) OP AS_NUM(b))); \
} \
break;
ARITH_OP(OP_ADD, +)
ARITH_OP(OP_SUB, -)
ARITH_OP(OP_MUL, *)
ARITH_OP(OP_DIV, /)
#undef ARITH_OP
}
}
done:;
}
int main() { runvm(); }
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