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#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include "mnemonics.h"
#include "nqasm.h"
#include "lexer.h"
#include "parser.h"
#include "vector.h"
struct label {
const char *name;
uint16_t addr;
};
uint16_t addr;
static int cmp_label(const void *a, const void *b)
{
const struct label *la = a, *lb = b;
return strcmp(la->name, lb->name);
}
#define DEFINE_VECTOR(name, arraytype, arrayname, initsize) \
static struct name { \
struct vector v; \
arraytype arrayname[]; \
} *name; \
\
static int name ## _init(void) \
{ \
return !(name = vector_init(initsize, sizeof (arraytype), sizeof *name)); \
} \
\
static arraytype *name ## _append(void) \
{ \
struct vector *v = &name->v; \
arraytype *e = vector_append(&v); \
name = (struct name *)v; \
return e; \
}
DEFINE_VECTOR(labels, struct label, l, 8)
DEFINE_VECTOR(instrs, struct instruction, i, 256)
void add_instruction(const struct instruction *inst)
{
struct instruction *i = instrs_append();
if (!i) {
fprintf(stderr, "unable to allocate instruction\n");
exit(1);
}
*i = *inst;
addr += 2;
}
static long eval_argument(const struct argument *arg, uint16_t pc)
{
struct label *l;
switch (arg->type) {
case ARG_INTEGER: return arg->value;
case ARG_PC: return pc;
case ARG_LABEL:
l = vector_search(&labels->v, &(struct label) { .name = arg->label }, cmp_label);
if (l) return l->addr;
fprintf(stderr, "unknown label '%s'\n", arg->label);
exit(1);
default:
assert(0);
}
}
static void assemble_instruction(const struct instruction *inst, uint16_t pc)
{
const struct mnemonic *mnem = &mnemonics[inst->mnem];
uint16_t bits = mnem->bits;
const struct operand *ops = mnem->operands;
const struct argument *args = inst->args.args;
for (int i = 0; i < 3 && ops[i].type; i++) {
long value = eval_argument(args + i, pc);
switch (ops[i].type) {
case REG:
case REGPTR:
if (0 > value || value >= 8) {
fprintf(stderr, "invalid register\n");
exit(1);
}
break;
case IMM:
if (-0x80 > value || value > 0xff) {
fprintf(stderr, "immediate operand out of range\n");
exit(1);
}
break;
case PCOFF:
value -= pc;
if (-0x80 > value || value > 0x7f) {
fprintf(stderr, "pc offset operand out of range\n");
exit(1);
}
break;
default:
assert(0);
}
bits |= (value & 255) << ops[i].shift;
}
printf("%04x\n", bits);
}
void add_label(const char *name)
{
struct label *l = labels_append();
if (!l) {
fprintf(stderr, "unable to allocate label\n");
exit(1);
}
*l = (struct label) {
.name = name,
.addr = addr
};
}
int main(int argc, char **argv)
{
labels_init();
instrs_init();
yyparse();
vector_sort(&labels->v, cmp_label);
for (size_t i = 0; i < instrs->v.count; i++) {
assemble_instruction(instrs->i + i, 2 * i);
}
return 0;
}
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