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Return correct error statuses. Detect another illegally placed gate operator in an infix expression.

pre-master-46
Brian Taylor 2 years ago
committed by Holger Vogt
parent
commit
715ce8c809
  1. 99
      src/frontend/logicexp.c

99
src/frontend/logicexp.c

@ -748,17 +748,21 @@ static int infix_to_postfix(char* infix, DSTRING * postfix_p)
nlist = add_name_entry("first", NULL);
ds_clear(postfix_p);
while ( ( ltok = lexer_scan(lx) ) != 0 ) { // start while ltok loop
if (ltok == '(') { lparen_count++; }
if (ltok == ')') { rparen_count++; }
if (ltok == LEX_ID && last_tok == LEX_ID) {
fprintf(stderr, "ERROR (1) no gate operator between two identifiers\n");
status = 1;
goto err_return;
}
if (lex_gate_op(ltok) && lex_gate_op(last_tok)) {
fprintf(stderr, "ERROR (2) two consecutive gate operators\n");
status = 1;
goto err_return;
if (lex_gate_op(ltok)) {
if (lex_gate_op(last_tok)) {
fprintf(stderr, "ERROR (2) two consecutive gate operators\n");
status = 1;
goto err_return;
} else if (last_tok != LEX_ID && last_tok != ')') {
fprintf(stderr, "ERROR (2a) gate operator not after ID or rparen\n");
status = 1;
goto err_return;
}
}
if (last_tok == '~' && ltok != LEX_ID && ltok != '(') {
fprintf(stderr, "ERROR (3) \'~\' is not followed by an ID or lparen\n");
@ -785,15 +789,24 @@ static int infix_to_postfix(char* infix, DSTRING * postfix_p)
fflush(stdout);
}
} else if (ltok == '(') {
lparen_count++;
entry = add_name_entry(makestr(ltok), nlist);
if (push(&stack, entry->name)) goto err_return;
status = push(&stack, entry->name);
if (status) {
goto err_return;
}
} else if (ltok == ')') {
rparen_count++;
while ( stack.top != -1 && !eq(stack.array[stack.top], "(") ) {
ds_cat_printf(postfix_p, " %s", pop(&stack, &status));
if (status) goto err_return;
if (status) {
goto err_return;
}
}
pop(&stack, &status);
if (status) goto err_return;
if (status) {
goto err_return;
}
} else if (lex_gate_op(ltok) || ltok == '~') {
char *tokstr = makestr(ltok);
if (ltok == '~') { // change ~ id --> tilde_id and continue
@ -809,10 +822,15 @@ static int infix_to_postfix(char* infix, DSTRING * postfix_p)
}
while ( stack.top != -1 && !eq(stack.array[stack.top], "(") && get_precedence(stack.array[stack.top]) >= get_precedence(tokstr) ) {
ds_cat_printf(postfix_p, " %s", pop(&stack, &status));
if (status) goto err_return;
if (status) {
goto err_return;
}
}
entry = add_name_entry(tokstr, nlist);
if (push(&stack, entry->name)) goto err_return;
status = push(&stack, entry->name);
if (status) {
goto err_return;
}
} else {
fprintf(stderr, "ERROR (6) unexpected infix token %d \'%s\'\n",
ltok, lx->lexer_buf);
@ -832,9 +850,14 @@ static int infix_to_postfix(char* infix, DSTRING * postfix_p)
}
while (stack.top != -1) {
ds_cat_printf(postfix_p, " %s", pop(&stack, &status));
if (status) goto err_return;
if (status) {
goto err_return;
}
}
err_return:
if (status) {
fprintf(stderr, "ERROR invalid infix expression: %s\n", infix);
}
delete_lexer(lx);
clear_name_list(nlist);
return status;
@ -869,42 +892,43 @@ static int evaluate_postfix(char* postfix)
while ( ( ltok = lexer_scan(lx) ) != 0 ) { // while ltok loop
if (ltok == LEX_ID) {
entry = add_name_entry(lx->lexer_buf, nlist);
if (push(&stack, entry->name)) goto err_return;
status = push(&stack, entry->name);
if (status) {
goto err_return;
}
} else if (ltok == '~') {
operand1 = pop(&stack, &status);
if (status) goto err_return;
if (status) {
goto err_return;
}
sprintf(tmp, "%s%d", TMP_PREFIX, count);
count++;
gp = new_gate('~', tmp, operand1, NULL);
gp = insert_gate(gp);
entry = add_name_entry(tmp, nlist);
if (push(&stack, entry->name)) goto err_return;
status = push(&stack, entry->name);
if (status) {
goto err_return;
}
} else {
operand2 = pop(&stack, &status);
if (status) goto err_return;
if (status) {
goto err_return;
}
operand1 = pop(&stack, &status);
if (status) goto err_return;
if (ltok == '|') {
sprintf(tmp, "%s%d", TMP_PREFIX, count);
count++;
gp = new_gate('|', tmp, operand1, operand2);
gp = insert_gate(gp);
entry = add_name_entry(tmp, nlist);
if (push(&stack, entry->name)) goto err_return;
} else if (ltok == '^') {
sprintf(tmp, "%s%d", TMP_PREFIX, count);
count++;
gp = new_gate('^', tmp, operand1, operand2);
gp = insert_gate(gp);
entry = add_name_entry(tmp, nlist);
if (push(&stack, entry->name)) goto err_return;
} else if (ltok == '&') {
if (status) {
goto err_return;
}
if (lex_gate_op(ltok)) {
sprintf(tmp, "%s%d", TMP_PREFIX, count);
count++;
gp = new_gate('&', tmp, operand1, operand2);
gp = new_gate(ltok, tmp, operand1, operand2);
gp = insert_gate(gp);
entry = add_name_entry(tmp, nlist);
if (push(&stack, entry->name)) goto err_return;
status = push(&stack, entry->name);
if (status) {
goto err_return;
}
}
}
prevtok = ltok;
@ -915,7 +939,9 @@ static int evaluate_postfix(char* postfix)
sprintf(tmp, "%s%d", TMP_PREFIX, count);
count++;
n1 = tilde_tail(pop(&stack, &status), &ds1);
if (status) goto err_return;
if (status) {
goto err_return;
}
if (!skip && n1[0] == '~') {
gp = new_gate('~', tmp, n1 + 1, NULL);
gp->is_not = TRUE;
@ -927,6 +953,9 @@ static int evaluate_postfix(char* postfix)
ds_free(&ds1);
}
err_return:
if (status) {
fprintf(stderr, "ERROR invalid postfix expression: %s\n", postfix);
}
delete_lexer(lx);
clear_name_list(nlist);
return status;

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