+/* maintain an array of the instructions we have parsed */
+static
+struct instruction_list_ *instr_list_new(void) {
+ size_t init_size = 1024;
+ struct instruction_list_ *il = malloc(IL_SIZE(init_size));
+ if (il == NULL) {
+ fprintf(stderr, "%s():%s\n", "malloc", strerror(errno));
+ return NULL;
+ }
+ il->allocated = init_size;
+ il->entries = 0;
+ return il;
+}
+
+static
+int instr_list_insert(struct instruction_list_ **il, struct instruction_ *i) {
+ /* make room make room */
+ if ((*il)->entries - 1 == (*il)->allocated) {
+ size_t new_allocated = (*il)->allocated + 1024;
+ void *tmp_ptr = realloc(*il, IL_SIZE(new_allocated));
+ if (tmp_ptr == NULL) {
+ fprintf(stderr, "%s():%s\n", "realloc", strerror(errno));
+ return -1;
+ }
+ *il = tmp_ptr;
+ (*il)->allocated = new_allocated;
+ }
+
+ (*il)->instr[(*il)->entries] = i;
+ (*il)->entries += 1;
+ return 0;
+}
+
+/* also maintain a list of the labels we've seen, indexed back to their instructions. */
+/* FIXME: ugh, this could all stand to be rewritten cleaner */
+/* these lists could be rearranged to be a lot easier to wrangle and/or maybe use common interfaces */
+/* they were thrown together on the fly */
+static
+struct label_list_ *label_list_new(void) {
+ size_t init_size = 256;
+ struct label_list_ *ll = malloc(LL_SIZE(init_size));
+ if (ll == NULL) {
+ fprintf(stderr, "%s():%s\n", "malloc", strerror(errno));
+ return NULL;
+ }
+ ll->allocated = init_size;
+ ll->entries = 0;
+ return ll;
+}
+
+/* instr here is index into instruction list */
+static
+int label_list_insert(struct label_list_ **ll, struct instruction_ **instr) {
+ if ((*ll)->entries - 1 == (*ll)->allocated) {
+ size_t new_allocated = (*ll)->allocated + 256;
+ void *tmp_ptr = realloc(*ll, IL_SIZE(new_allocated));
+ if (tmp_ptr == NULL) {
+ fprintf(stderr, "%s():%s\n", "realloc", strerror(errno));
+ return -1;
+ }
+ *ll = tmp_ptr;
+ (*ll)->allocated = new_allocated;
+ }
+
+ DEBUG_PRINTF("TRACE: adding label '%s'\n", (*instr)->label);
+
+ (*ll)->label[(*ll)->entries].label = (*instr)->label;
+ (*ll)->label[(*ll)->entries].instr = instr;
+ (*ll)->entries += 1;
+ return 0;
+}
+
+/* locate the index of a labelled instruction within the instruction list */
+static
+struct instruction_ **label_list_find_instr(struct label_list_ *ll, char *label) {
+ size_t x;
+
+ for (x = 0; x < ll->entries; x++) {
+ if (strcmp(ll->label[x].label, label) == 0)
+ return ll->label[x].instr;
+ }
+ return NULL;
+}
+
+/* look up the address of a calculated address */
+static
+int label_list_find_addr(struct label_list_ *ll, char *label, DCPU16_WORD *addr) {
+ size_t x;
+
+ for (x = 0; x < ll->entries; x++) {
+ if (strcmp(ll->label[x].label, label) == 0) {
+ if (ll->label[x].ready == 1) {
+ *addr = ll->label[x].addr;
+ return 0;
+ }
+ }
+ }
+ return -1;
+}
+
+/* attempt to determine the addresses of labels */
+static
+void label_addr_calculate_(struct instruction_list_ *il, struct label_list_ *ll) {
+ size_t i;
+
+ /* walk through labels */
+ for (i = 0; i < ll->entries; i++) {
+ struct instruction_ **instr;
+ unsigned int word_count = 0;
+
+ if (ll->label[i].ready)
+ continue;
+
+ /*
+ * walk backwards through the list of instructions
+ * until we get to the start or a known prior label address
+ * update our label
+ */
+ for (instr = ll->label[i].instr; instr >= il->instr; instr--) {
+
+ word_count += (*instr)->length;
+
+ if ((*instr)->label
+ && strcmp((*instr)->label, ll->label[i].label)) {
+ DCPU16_WORD addr;
+
+ if (label_list_find_addr(ll, (*instr)->label, &addr)) {
+ fprintf(stderr, "internal error: incomplete prior address for '%s' while calculating '%s'\n",
+ (*instr)->label,
+ ll->label[i].label);
+ continue;
+ }
+ word_count += addr;
+ break;
+ }
+ }
+ ll->label[i].addr = word_count;
+ ll->label[i].ready = 1;
+ DEBUG_PRINTF("label '%s' has addr of 0x%04x\n", ll->label[i].label, word_count);
+ }
+}
+
+static
+void instr_free_(struct instruction_ *i) {
+ if (i->label)
+ free(i->label);
+ if (i->opcode)
+ free(i->opcode);
+ while (i->operands) {
+ struct operand_ *o = i->operands;
+
+ i->operands = o->next;
+ free(o);
+ }
+
+ free(i);
+}
+
+/* generate the nibble for a given basic opcode */
+static
+int opcode_bits_(char *opcode) {
+ static struct {
+ char op[4];
+ char value;
+ } opcodes_lower_nibble[] = {
+ { "JSR", 0x00 },
+ /* { "future nbi instruction", 0x00 }, */
+ { "SET", 0x01 },
+ { "ADD", 0x02 },
+ { "SUB", 0x03 },
+ { "MUL", 0x04 },
+ { "DIV", 0x05 },
+ { "MOD", 0x06 },
+ { "SHL", 0x07 },
+ { "SHR", 0x08 },
+ { "AND", 0x09 },
+ { "BOR", 0x0a },
+ { "XOR", 0x0b },
+ { "IFE", 0x0c },
+ { "IFN", 0x0d },
+ { "IFG", 0x0e },
+ { "IFB", 0x0f },
+ { "", 0x00 }
+ }, *o;
+
+ for (o = opcodes_lower_nibble; o->op[0]; o++) {
+ if (strcasecmp(o->op, opcode) == 0)
+ break;
+ }
+
+ if (o->op[0] == '\0') {
+ fprintf(stderr, "unknown instruction '%s'\n", opcode);
+ return -1;
+ }
+
+ return o->value;
+}
+
+/* generate the six bits for a given nbi opcode (aka first operand to opcode 0x00) */
+static
+int nbi_opcode_bits_(char *nbi_opcode) {
+ static struct {
+ char op[4];
+ char value;
+ } nbi_opcodes_bits[] = {
+ { " ", 0x00 }, /* reserved for future */
+ { "JSR", 0x01 },
+ { "", 0x00 }
+ }, *o;
+
+ for (o = nbi_opcodes_bits; o->op[0]; o++) {
+ if (strcasecmp(o->op, nbi_opcode) == 0)
+ break;
+ }
+
+ if (o->op[0] == '\0') {
+ fprintf(stderr, "unknown nbi instruction '%s'\n", o->op);
+ return -1;
+ }
+
+ return o->value;
+}
+
+/* convert register character like 'x' to value like 0x03 */
+static inline
+unsigned int register_enumerate_(char r) {
+ const char regs[] = "AaBbCcXxYyZzIiJj";
+ const char *x = strchr(regs, r);
+
+ if (x)
+ return (x - regs)/2;
+
+ fprintf(stderr, "internal error, unknown register character 0x%02x\n", r);
+ return -1;
+}
+
+/* removes all occurences of chars from buf */
+static inline
+void buf_strip_chars_(char *buf, char *chars) {
+ char *s, *d;
+
+ for (s = d = buf; *s; s++, d++) {
+ while (*s && strchr(chars, *s)) {
+ s++;
+ }
+ if (!*s)
+ break;
+ *d = *s;
+ }
+ *d = *s;
+}
+
+/* value_bits_
+ * generate the six bits for a given operand string
+ * returns -1 if it could not parse the operand
+ * returns -2 if it could not parse the operand due to an unresolved label
+ * notes: nextword may be overwritten even if it's not used in final instruction
+ */
+static
+int value_bits_(struct label_list_ *ll, char *operand_orig, DCPU16_WORD *nextword, unsigned int *nextwordused, unsigned int allow_short_labels) {
+ static char *operand = NULL;
+ static size_t operand_sz = 0;
+
+ unsigned long l;
+ char *o, *ep;
+
+ /*
+ Our operand working buffer shouldn't ever need to be too big,
+ but DAT might blow that assumption.
+ */
+ if (operand_sz <= strlen(operand_orig)) {
+ void *tmp_ptr;
+ size_t new_sz = strlen(operand_orig);
+
+ if (new_sz < 256)
+ new_sz = 256;
+ new_sz += 256;
+
+ DEBUG_PRINTF("%s: allocating buffer of size %zu\n", __func__, new_sz);
+ tmp_ptr = realloc(operand, new_sz);
+ if (tmp_ptr == NULL) {
+ fprintf(stderr, "%s(%zu):%s\n", "realloc", new_sz, strerror(errno));
+ return -1;
+ }
+ operand = tmp_ptr;
+ operand_sz = new_sz;
+ }
+
+ o = strcpy(operand, operand_orig);
+
+ DEBUG_PRINTF("%s: operand '%s' ", __func__, operand); /* completed later */
+
+ /* this is a very stupid parser */
+
+ /* first, let's trim all whitespace out of string at once to make parsing easier */
+ buf_strip_chars_(operand, " \t\n");
+
+ /* single character might match a register */
+ if (strlen(operand) == 1
+ && strchr("AaBbCcXxYyZzIiJj", *operand)) {
+ DEBUG_PRINTF("is register %c\n", *operand);
+ return register_enumerate_(*operand);
+ }
+
+ /* easy matches */
+ if (strcasecmp(operand, "POP") == 0) {
+ DEBUG_PRINTF("is POP\n");
+ return 0x18;
+ }
+ if (strcasecmp(operand, "PUSH") == 0) {
+ DEBUG_PRINTF("is PUSH\n");
+ return 0x19;
+ }
+ if (strcasecmp(operand, "PEEK") == 0) {
+ DEBUG_PRINTF("is PEEK\n");
+ return 0x1a;
+ }
+ if (strcasecmp(operand, "SP") == 0) {
+ DEBUG_PRINTF("is register SP\n");
+ return 0x1b;
+ }
+ if (strcasecmp(operand, "PC") == 0) {
+ DEBUG_PRINTF("is register PC\n");
+ return 0x1c;
+ }
+ if (strcasecmp(operand, "O") == 0) {
+ DEBUG_PRINTF("is register O\n");
+ return 0x1d;
+ }
+
+ /* is the operand [bracketed]? */
+ if (operand[0] == '[' && operand[strlen(operand) - 1] == ']') {
+ /* eat the brackets */
+ operand[strlen(operand) - 1] = '\0';
+ operand++;
+
+ /* is it [register]? */
+ if (strlen(operand) == 1
+ && strchr("AaBbCcXxYyZzIiJj", *operand)) {
+ DEBUG_PRINTF("is dereferenced register %c\n", *operand);
+ return 0x08 | register_enumerate_(*operand);
+ }
+
+ /* is it [register+something]? */
+ if ( (ep = strchr(operand, '+')) ) {
+ char *reg;
+ char *constant;
+
+ /* eat the plus */
+ *ep = '\0';
+ ep++;
+
+ /* figure out which one is which */
+ if (strlen(ep) == 1
+ && strchr("AaBbCcXxYyZzIiJj", *ep)) {
+ reg = ep;
+ constant = operand;
+ } else if (strlen(operand) == 1
+ && strchr("AaBbCcXxYyZzIiJj", *operand) ) {
+ reg = operand;
+ constant = ep;
+ } else {
+ DEBUG_PRINTF("is unparsable\n");
+ fprintf(stderr, "couldn't parse operand '%s'\n", operand_orig);
+ return -1;
+ }
+
+ /* check if something is understandable as a value */
+ errno = 0;
+ l = strtoul(constant, &ep, 0);
+ if (errno == 0
+ && (*constant && (*ep == '\0')) ) {
+ /* string conversion went without issue */
+ /* validate it will fit in a word */
+ if (l > 0xffff) {
+ DEBUG_PRINTF("is out of range\n");
+ fprintf(stderr, "constant invalid in operand '%s'\n", operand_orig);
+ return -1;
+ }
+
+ /* seems fine */
+ *nextword = l & 0xffff;
+ *nextwordused += 1;
+ DEBUG_PRINTF("is a dereferenced register (%c) + constant (%hu)\n", *reg, *nextword);
+ return 0x10 | register_enumerate_(*reg);
+ } else if (errno) {
+ DEBUG_PRINTF("is out of range\n");
+ fprintf(stderr, "trouble with operand '%s': %s\n", operand_orig, strerror(errno));
+ return -1;
+ }
+
+ /* what? still here? assume it's a label, I guess */
+ /* try to populate nextword with label address */
+ if (label_list_find_addr(ll, operand, nextword)) {
+ DEBUG_PRINTF("(deferred label resolution)\n");
+ *nextwordused += 1;
+ return -2;
+ }
+ DEBUG_PRINTF("is a dereferenced register (%c) + label\n", *reg);
+ *nextwordused += 1;
+ return 0x10 | register_enumerate_(*reg);
+ }
+
+ /* it must just be a dereferenced literal then */
+
+ errno = 0;
+ l = strtoul(operand, &ep, 0);
+ if (errno == 0
+ && (*operand && (*ep == '\0')) ) {
+ /* string conversion went without issue */
+ /* validate it will fit in a word */
+ if (l > 0xffff) {
+ DEBUG_PRINTF("is out of range\n");
+ fprintf(stderr, "constant invalid in operand '%s'\n", operand_orig);
+ return -1;
+ }
+
+ DEBUG_PRINTF("is a dereferenced literal value (%hu)\n", *nextword);
+ *nextword = l & 0xffff;
+ *nextwordused += 1;
+ return 0x1e;
+ } else if (errno) {
+ DEBUG_PRINTF("is out of range\n");
+ fprintf(stderr, "trouble with operand '%s': %s\n", operand_orig, strerror(errno));
+ }
+
+ /* not a number? try a label */
+ if (label_list_find_addr(ll, operand, nextword)) {
+ DEBUG_PRINTF("(deferred label resolution)\n");
+ *nextwordused += 1;
+ return -2;
+ }
+ DEBUG_PRINTF("is a dereferenced label\n");
+ *nextwordused += 1;
+ return 0x1e;
+ }
+
+ /* left with a literal or a label, then */
+
+ errno = 0;
+ l = strtoul(operand, &ep, 0);
+ if (errno == 0
+ || (*operand && (*ep == '\0')) ) {
+ if (l > 0xffff) {
+ DEBUG_PRINTF("is out of range\n");
+ fprintf(stderr, "constant invalid in operand '%s'\n", operand_orig);
+ return -1;
+ }
+
+ DEBUG_PRINTF("is literal value (%lu)\n", l);
+ if (l < 0x20) {
+ return l + 0x20;
+ }
+
+ *nextword = l & 0xffff;
+ *nextwordused += 1;
+ return 0x1f;
+ }
+
+ /* try to populate nextword with label address */
+ if (label_list_find_addr(ll, operand, nextword)) {
+ DEBUG_PRINTF("(deferred label resolution)\n");
+ /* assume non-small literal value */
+ *nextwordused += 1;
+ return -2;
+ }
+
+ DEBUG_PRINTF("is label '%s' (0x%02hx)\n", operand, *nextword);
+ if (*nextword < 0x20 && allow_short_labels) {
+ DEBUG_PRINTF("small value label win\n");
+ return (0x20 + *nextword) & 0x3f;
+ }
+
+ *nextwordused += 1;
+ return 0x1f;
+}
+
+static inline
+int instruction_print_(struct instruction_ *i, unsigned int with_label) {
+ struct operand_ *o;
+ int r;
+
+ if (with_label)
+ r = printf("%-16s %3s", i->label ? i->label : "", i->opcode);
+ else
+ r = printf("%3s", i->opcode);