NetBSD/gnu/usr.bin/groff/troff/number.cc

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// -*- C++ -*-
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/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
Written by James Clark (jjc@jclark.com)
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This file is part of groff.
groff is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
groff is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
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with groff; see the file COPYING. If not, write to the Free Software
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Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "troff.h"
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#include "symbol.h"
#include "hvunits.h"
#include "env.h"
#include "token.h"
#include "div.h"
vunits V0;
hunits H0;
int hresolution = 1;
int vresolution = 1;
int units_per_inch;
int sizescale;
static int parse_expr(units *v, int scale_indicator, int parenthesised);
static int start_number();
int get_vunits(vunits *res, unsigned char si)
{
if (!start_number())
return 0;
units x;
if (parse_expr(&x, si, 0)) {
*res = vunits(x);
return 1;
}
else
return 0;
}
int get_hunits(hunits *res, unsigned char si)
{
if (!start_number())
return 0;
units x;
if (parse_expr(&x, si, 0)) {
*res = hunits(x);
return 1;
}
else
return 0;
}
int get_number(units *res, unsigned char si)
{
if (!start_number())
return 0;
units x;
if (parse_expr(&x, si, 0)) {
*res = x;
return 1;
}
else
return 0;
}
int get_integer(int *res)
{
if (!start_number())
return 0;
units x;
if (parse_expr(&x, 0, 0)) {
*res = x;
return 1;
}
else
return 0;
}
enum incr_number_result { BAD, ABSOLUTE, INCREMENT, DECREMENT };
static incr_number_result get_incr_number(units *res, unsigned char);
int get_vunits(vunits *res, unsigned char si, vunits prev_value)
{
units v;
switch (get_incr_number(&v, si)) {
case BAD:
return 0;
case ABSOLUTE:
*res = v;
break;
case INCREMENT:
*res = prev_value + v;
break;
case DECREMENT:
*res = prev_value - v;
break;
default:
assert(0);
}
return 1;
}
int get_hunits(hunits *res, unsigned char si, hunits prev_value)
{
units v;
switch (get_incr_number(&v, si)) {
case BAD:
return 0;
case ABSOLUTE:
*res = v;
break;
case INCREMENT:
*res = prev_value + v;
break;
case DECREMENT:
*res = prev_value - v;
break;
default:
assert(0);
}
return 1;
}
int get_number(units *res, unsigned char si, units prev_value)
{
units v;
switch (get_incr_number(&v, si)) {
case BAD:
return 0;
case ABSOLUTE:
*res = v;
break;
case INCREMENT:
*res = prev_value + v;
break;
case DECREMENT:
*res = prev_value - v;
break;
default:
assert(0);
}
return 1;
}
int get_integer(int *res, int prev_value)
{
units v;
switch (get_incr_number(&v, 0)) {
case BAD:
return 0;
case ABSOLUTE:
*res = v;
break;
case INCREMENT:
*res = prev_value + int(v);
break;
case DECREMENT:
*res = prev_value - int(v);
break;
default:
assert(0);
}
return 1;
}
static incr_number_result get_incr_number(units *res, unsigned char si)
{
if (!start_number())
return BAD;
incr_number_result result = ABSOLUTE;
if (tok.ch() == '+') {
tok.next();
result = INCREMENT;
}
else if (tok.ch() == '-') {
tok.next();
result = DECREMENT;
}
if (parse_expr(res, si, 0))
return result;
else
return BAD;
}
static int start_number()
{
while (tok.space())
tok.next();
if (tok.newline()) {
warning(WARN_MISSING, "missing number");
return 0;
}
if (tok.tab()) {
warning(WARN_TAB, "tab character where number expected");
return 0;
}
if (tok.right_brace()) {
warning(WARN_RIGHT_BRACE, "`\\}' where number expected");
return 0;
}
return 1;
}
enum { OP_LEQ = 'L', OP_GEQ = 'G', OP_MAX = 'X', OP_MIN = 'N' };
#define SCALE_INDICATOR_CHARS "icPmnpuvMsz"
static int parse_term(units *v, int scale_indicator, int parenthesised);
static int parse_expr(units *v, int scale_indicator, int parenthesised)
{
int result = parse_term(v, scale_indicator, parenthesised);
while (result) {
if (parenthesised)
tok.skip();
int op = tok.ch();
switch (op) {
case '+':
case '-':
case '/':
case '*':
case '%':
case ':':
case '&':
tok.next();
break;
case '>':
tok.next();
if (tok.ch() == '=') {
tok.next();
op = OP_GEQ;
}
else if (tok.ch() == '?') {
tok.next();
op = OP_MAX;
}
break;
case '<':
tok.next();
if (tok.ch() == '=') {
tok.next();
op = OP_LEQ;
}
else if (tok.ch() == '?') {
tok.next();
op = OP_MIN;
}
break;
case '=':
tok.next();
if (tok.ch() == '=')
tok.next();
break;
default:
return result;
}
units v2;
if (!parse_term(&v2, scale_indicator, parenthesised))
return 0;
int overflow = 0;
switch (op) {
case '<':
*v = *v < v2;
break;
case '>':
*v = *v > v2;
break;
case OP_LEQ:
*v = *v <= v2;
break;
case OP_GEQ:
*v = *v >= v2;
break;
case OP_MIN:
if (*v > v2)
*v = v2;
break;
case OP_MAX:
if (*v < v2)
*v = v2;
break;
case '=':
*v = *v == v2;
break;
case '&':
*v = *v > 0 && v2 > 0;
break;
case ':':
*v = *v > 0 || v2 > 0;
case '+':
if (v2 < 0) {
if (*v < INT_MIN - v2)
overflow = 1;
}
else if (v2 > 0) {
if (*v > INT_MAX - v2)
overflow = 1;
}
if (overflow) {
error("addition overflow");
return 0;
}
*v += v2;
break;
case '-':
if (v2 < 0) {
if (*v > INT_MAX + v2)
overflow = 1;
}
else if (v2 > 0) {
if (*v < INT_MIN + v2)
overflow = 1;
}
if (overflow) {
error("subtraction overflow");
return 0;
}
*v -= v2;
break;
case '*':
if (v2 < 0) {
if (*v > 0) {
if (*v > -(unsigned)INT_MIN / -(unsigned)v2)
overflow = 1;
}
else if (-(unsigned)*v > INT_MAX / -(unsigned)v2)
overflow = 1;
}
else if (v2 > 0) {
if (*v > 0) {
if (*v > INT_MAX / v2)
overflow = 1;
}
else if (-(unsigned)*v > -(unsigned)INT_MIN / v2)
overflow = 1;
}
if (overflow) {
error("multiplication overflow");
return 0;
}
*v *= v2;
break;
case '/':
if (v2 == 0) {
error("division by zero");
return 0;
}
*v /= v2;
break;
case '%':
if (v2 == 0) {
error("modulus by zero");
return 0;
}
*v %= v2;
break;
default:
assert(0);
}
}
return result;
}
static int parse_term(units *v, int scale_indicator, int parenthesised)
{
int negative = 0;
for (;;)
if (parenthesised && tok.space())
tok.next();
else if (tok.ch() == '+')
tok.next();
else if (tok.ch() == '-') {
tok.next();
negative = !negative;
}
else
break;
unsigned char c = tok.ch();
switch (c) {
case '|':
// | is not restricted to the outermost level
// tbl uses this
tok.next();
if (!parse_term(v, scale_indicator, parenthesised))
return 0;
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int tem;
tem = (scale_indicator == 'v'
? curdiv->get_vertical_position().to_units()
: curenv->get_input_line_position().to_units());
if (tem >= 0) {
if (*v < INT_MIN + tem) {
error("numeric overflow");
return 0;
}
}
else {
if (*v > INT_MAX + tem) {
error("numeric overflow");
return 0;
}
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}
*v -= tem;
if (negative) {
if (*v == INT_MIN) {
error("numeric overflow");
return 0;
}
*v = -*v;
}
return 1;
case '(':
tok.next();
c = tok.ch();
if (c == ')') {
warning(WARN_SYNTAX, "empty parentheses");
tok.next();
*v = 0;
return 1;
}
else if (c != 0 && strchr(SCALE_INDICATOR_CHARS, c) != 0) {
tok.next();
if (tok.ch() == ';') {
tok.next();
scale_indicator = c;
}
else {
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error("expected `;' after scale-indicator (got %1)",
tok.description());
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return 0;
}
}
else if (c == ';') {
scale_indicator = 0;
tok.next();
}
if (!parse_expr(v, scale_indicator, 1))
return 0;
tok.skip();
if (tok.ch() != ')') {
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warning(WARN_SYNTAX, "missing `)' (got %1)", tok.description());
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}
else
tok.next();
if (negative) {
if (*v == INT_MIN) {
error("numeric overflow");
return 0;
}
*v = -*v;
}
return 1;
case '.':
*v = 0;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
*v = 0;
do {
if (*v > INT_MAX/10) {
error("numeric overflow");
return 0;
}
*v *= 10;
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if (*v > INT_MAX - (int(c) - '0')) {
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error("numeric overflow");
return 0;
}
*v += c - '0';
tok.next();
c = tok.ch();
} while (csdigit(c));
break;
case '/':
case '*':
case '%':
case ':':
case '&':
case '>':
case '<':
case '=':
warning(WARN_SYNTAX, "empty left operand");
*v = 0;
return 1;
default:
warning(WARN_NUMBER, "numeric expression expected (got %1)",
tok.description());
return 0;
}
int divisor = 1;
if (tok.ch() == '.') {
tok.next();
for (;;) {
c = tok.ch();
if (!csdigit(c))
break;
// we may multiply the divisor by 254 later on
if (divisor <= INT_MAX/2540 && *v <= (INT_MAX - 9)/10) {
*v *= 10;
*v += c - '0';
divisor *= 10;
}
tok.next();
}
}
int si = scale_indicator;
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int do_next = 0;
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if ((c = tok.ch()) != 0 && strchr(SCALE_INDICATOR_CHARS, c) != 0) {
switch (scale_indicator) {
case 'z':
if (c != 'u' && c != 'z') {
warning(WARN_SCALE,
"only `z' and `u' scale indicators valid in this context");
break;
}
si = c;
break;
case 0:
warning(WARN_SCALE, "scale indicator invalid in this context");
break;
case 'u':
si = c;
break;
default:
if (c == 'z') {
warning(WARN_SCALE, "`z' scale indicator invalid in this context");
break;
}
si = c;
break;
}
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// Don't do tok.next() here because the next token might be \s, which
// would affect the interpretation of m.
do_next = 1;
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}
switch (si) {
case 'i':
*v = scale(*v, units_per_inch, divisor);
break;
case 'c':
*v = scale(*v, units_per_inch*100, divisor*254);
break;
case 0:
case 'u':
if (divisor != 1)
*v /= divisor;
break;
case 'p':
*v = scale(*v, units_per_inch, divisor*72);
break;
case 'P':
*v = scale(*v, units_per_inch, divisor*6);
break;
case 'm':
{
// Convert to hunits so that with -Tascii `m' behaves as in nroff.
hunits em = curenv->get_size();
*v = scale(*v, em.is_zero() ? hresolution : em.to_units(), divisor);
}
break;
case 'M':
{
hunits em = curenv->get_size();
*v = scale(*v, em.is_zero() ? hresolution : em.to_units(), divisor*100);
}
break;
case 'n':
{
// Convert to hunits so that with -Tascii `n' behaves as in nroff.
hunits en = curenv->get_size()/2;
*v = scale(*v, en.is_zero() ? hresolution : en.to_units(), divisor);
}
break;
case 'v':
*v = scale(*v, curenv->get_vertical_spacing().to_units(), divisor);
break;
case 's':
while (divisor > INT_MAX/(sizescale*72)) {
divisor /= 10;
*v /= 10;
}
*v = scale(*v, units_per_inch, divisor*sizescale*72);
break;
case 'z':
*v = scale(*v, sizescale, divisor);
break;
default:
assert(0);
}
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if (do_next)
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tok.next();
if (negative) {
if (*v == INT_MIN) {
error("numeric overflow");
return 0;
}
*v = -*v;
}
return 1;
}
units scale(units n, units x, units y)
{
assert(x >= 0 && y > 0);
if (x == 0)
return 0;
if (n >= 0) {
if (n <= INT_MAX/x)
return (n*x)/y;
}
else {
if (-(unsigned)n <= -(unsigned)INT_MIN/x)
return (n*x)/y;
}
double res = n*double(x)/double(y);
if (res > INT_MAX) {
error("numeric overflow");
return INT_MAX;
}
else if (res < INT_MIN) {
error("numeric overflow");
return INT_MIN;
}
return int(res);
}
vunits::vunits(units x)
{
// don't depend on the rounding direction for division of negative integers
if (vresolution == 1)
n = x;
else
n = (x < 0
? -((-x + vresolution/2 - 1)/vresolution)
: (x + vresolution/2 - 1)/vresolution);
}
hunits::hunits(units x)
{
// don't depend on the rounding direction for division of negative integers
if (hresolution == 1)
n = x;
else
n = (x < 0
? -((-x + hresolution/2 - 1)/hresolution)
: (x + hresolution/2 - 1)/hresolution);
}