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#include "linetab.h"
lineref_t *linerefs[32769];
int refcounts[32769];
int lines_exist[32769];
unsigned char last_cmd, on_op;
int last_cmd_pos;
void add_lineref(unsigned short from, unsigned short pos) {
lineref_t *p;
int c;
unsigned short to;
to = fp2int(program + pos);
if(to > 32767) return;
p = linerefs[to];
c = refcounts[to];
if(c) {
p = realloc(p, sizeof(lineref_t) * (c + 1));
} else {
p = malloc(sizeof(lineref_t));
}
if(!p) die("Out of memory.");
linerefs[to] = p;
linerefs[to][c].lineno = from;
linerefs[to][c].pos = pos;
linerefs[to][c].cmd = last_cmd;
c++;
refcounts[to] = c;
}
/* makes sure a numeric constant isn't start of an expression. */
int is_standalone_num(unsigned short pos) {
if(program[pos] != OP_NUMCONST) return 0;
switch(program[pos + 7]) {
case OP_EOS:
case OP_EOL:
case OP_COMMA:
return 1;
default:
return 0;
}
}
CALLBACK(start_stmt) {
lines_exist[lineno] = 1;
}
CALLBACK(got_cmd) {
last_cmd = tok;
last_cmd_pos = pos;
on_op = 0;
}
void computed_msg(unsigned short lineno) {
static int last_lineno = -1;
char *cmd;
/* avoid duplicate warnings */
if(lineno == last_lineno) return;
last_lineno = lineno;
switch(last_cmd) {
case CMD_GOTO:
cmd = "GOTO"; break;
case CMD_GO_TO:
cmd = "GO TO"; break;
case CMD_GOSUB:
cmd = "GOSUB"; break;
case CMD_RESTORE:
cmd = "RESTORE"; break;
case CMD_TRAP:
cmd = "TRAP"; break;
case CMD_ON:
if(on_op == OP_GOSUB)
cmd = "ON/GOSUB";
else
cmd = "ON/GOTO";
break;
case CMD_LIST:
cmd = "LIST";
break;
default: /* should never happen! */
cmd = "???"; break;
}
fprintf(stderr, "%s: Warning: Computed %s at line %d.\n", self, cmd, lineno);
}
CALLBACK(got_var) {
switch(last_cmd) {
/* any use of a variable in the arguments to these means
we can't renumber that argument. */
case CMD_GOTO:
case CMD_GO_TO:
case CMD_GOSUB:
case CMD_RESTORE:
case CMD_TRAP:
case CMD_LIST:
computed_msg(lineno);
break;
case CMD_ON:
/* vars are OK in ON, before the GOTO or GOSUB */
if(on_op) computed_msg(lineno);
break;
default:
break;
}
}
CALLBACK(got_exp) {
unsigned char last_tok = program[pos - 1];
int standalone;
if(last_cmd == CMD_ON) {
if(tok == OP_GOTO || tok == OP_GOSUB)
on_op = tok;
}
if(tok != OP_NUMCONST) return;
/* beware: standalone only means nothing *follows* the constant
in the same expression. still have to check last_tok to see
what came before. */
standalone = is_standalone_num(pos);
switch(last_cmd) {
/* these take a single argument */
case CMD_GOTO:
case CMD_GO_TO:
case CMD_GOSUB:
case CMD_RESTORE:
case CMD_TRAP:
if((pos == last_cmd_pos + 1) && standalone) {
add_lineref(lineno, pos + 1);
} else {
computed_msg(lineno);
}
break;
case CMD_IF:
/* this only applies to bare line numbers, like IF A THEN 1000,
not IF A THEN GOTO 1000 (or anything else after THEN). */
if(last_tok == OP_THEN) {
add_lineref(lineno, pos + 1);
}
break;
case CMD_ON: {
/* takes arbitrary number of arguments */
switch(last_tok) {
case OP_GOTO:
case OP_GOSUB:
case OP_COMMA:
if(standalone)
add_lineref(lineno, pos + 1);
else
computed_msg(lineno);
break;
default:
break;
}
}
break;
case CMD_LIST: {
/* takes one or two arguments */
switch(last_tok) {
case CMD_LIST:
case OP_COMMA:
if(standalone)
add_lineref(lineno, pos + 1);
else
computed_msg(lineno);
break;
default:
break;
}
}
default:
break;
}
}
void build_ref_table(void) {
on_start_stmt = start_stmt;
on_cmd_token = got_cmd;
on_exp_token = got_exp;
on_var_token = got_var;
walk_all_code();
on_start_stmt = on_cmd_token = on_exp_token = on_var_token = 0;
}
void free_ref_table(void) {
int i;
for(i = 0; i < 32768; i++)
if(linerefs[i]) free(linerefs[i]);
}
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