branch()
{
register char c;
register int i;
extern char getch();
# ifdef xMTR2
if (tTf(16, -1))
printf(">>branch: ");
# endif
/* see if conditional */
while ((c = getch()) > 0)
if (c != ' ' && c != '\t')
break;
if (c == '?')
{
/* got a conditional; evaluate it */
Oneline = TRUE;
macinit(&getch, 0, 0);
i = expr();
if (i <= 0)
{
/* no branch */
# ifdef xMTR2
if (tTf(16, 0))
printf("no branch\n");
# endif
getfilename();
return;
}
}
else
{
Peekch = c;
}
/* get the target label */
if (branchto(getfilename()) == 0)
if (branchto(macro("{default}")) == 0)
{
Peekch = -1;
printf("Cannot branch\n");
}
return;
}
static void
tparm(char *outp, char *cp, int p1, int p2)
{
int c, op, vars[26], stack[10], top, sign;
#define PUSH(i) (stack [++top] = (i))
#define POP() (stack [top--])
if (!cp)
TPARMERR("null arg");
top = 0;
while ((c = *cp++))
{
if (c != '%')
{
*outp++ = c;
continue;
}
op = stack[top];
if (*cp == '0')
++cp;
switch (c = *cp++)
{
case 'd': /* PRINTING CASES */
if (op < 10)
goto one;
if (op < 100)
goto two;
/* fall into... */
case '3':
three:
if (c == '3' && *cp++ != 'd')
TPARMERR("bad char after %3");
*outp++ = (op / 100) | '0';
op %= 100;
/* fall into... */
case '2':
if (op >= 100)
goto three;
if (c == '2' && *cp++ != 'd')
TPARMERR("bad char after %2");
two:
*outp++ = op / 10 | '0';
one:
*outp++ = op % 10 | '0';
(void) POP();
continue;
case 'c':
*outp++ = op;
(void) POP();
break;
case '%':
*outp++ = c;
break;
/*
// %i: shorthand for increment first two parms.
// Useful for terminals that start numbering from
// one instead of zero (like ANSI terminals).
*/
case 'i':
p1++;
p2++;
break;
case 'p': /* %pi: push the ith parameter */
switch (c = *cp++)
{
case '1':
PUSH(p1);
break;
case '2':
PUSH(p2);
break;
default:
TPARMERR("bad parm number");
}
break;
case 'P': /* %Pi: pop from stack into variable i (a-z) */
vars[*cp++ - 'a'] = POP();
break;
case 'g': /* %gi: push variable i (a-z) */
PUSH(vars[*cp++ - 'a']);
break;
case '\'': /* %'c' : character constant */
PUSH(*cp++);
if (*cp++ != '\'')
TPARMERR("missing closing quote");
break;
case '{': /* %{nn} : integer constant. */
op = 0;
sign = 1;
if (*cp == '-')
{
sign = -1;
cp++;
}
else if (*cp == '+')
cp++;
while ((c = *cp++) >= '0' && c <= '9')
{
op = 10 * op + c - '0';
}
if (c != '}')
TPARMERR("missing closing brace");
PUSH(sign * op);
break;
/* binary operators */
case '+':
c = POP();
op = POP();
PUSH(op + c);
break;
case '-':
c = POP();
op = POP();
PUSH(op - c);
break;
case '*':
c = POP();
op = POP();
PUSH(op * c);
break;
case '/':
c = POP();
op = POP();
PUSH(op / c);
break;
case 'm':
c = POP();
op = POP();
PUSH(op % c);
break;
case '&':
c = POP();
op = POP();
PUSH(op & c);
break;
case '|':
c = POP();
op = POP();
PUSH(op | c);
break;
case '^':
c = POP();
op = POP();
PUSH(op ^ c);
break;
case '=':
c = POP();
op = POP();
PUSH(op = c);
break;
case '>':
c = POP();
op = POP();
PUSH(op > c);
break;
case '<':
c = POP();
op = POP();
PUSH(op < c);
break;
/* Unary operators. */
case '!':
stack[top] = !stack[top];
break;
case '~':
stack[top] = ~stack[top];
break;
/* Sorry, no unary minus, because minus is binary. */
/*
If-then-else. Implemented by a low level hack of
skipping forward until the match is found, counting
nested if-then-elses.
*/
case '?': /* IF - just a marker */
break;
case 't': /* THEN - branch if false */
if (!POP())
cp = branchto(cp, 'e');
break;
case 'e': /* ELSE - branch to ENDIF */
cp = branchto(cp, ';');
break;
case ';': /* ENDIF - just a marker */
break;
default:
TPARMERR("bad % sequence");
}
}
*outp = 0;
}
