BSD 4.4 Lite Usr.bin Sources

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diff --git a/usr.bin/m4/expr.c b/usr.bin/m4/expr.c
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+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Ozan Yigit at York University.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)expr.c	8.1 (Berkeley) 6/6/93";
+#endif /* not lint */
+
+#include <sys/cdefs.h>
+#include <stdio.h>
+
+/*
+ *      expression evaluator: performs a standard recursive
+ *      descent parse to evaluate any expression permissible
+ *      within the following grammar:
+ *
+ *      expr    :       query EOS
+ *      query   :       lor
+ *              |       lor "?" query ":" query
+ *      lor     :       land { "||" land }
+ *      land    :       bor { "&&" bor }
+ *      bor     :       bxor { "|" bxor }
+ *      bxor    :       band { "^" band }
+ *      band    :       eql { "&" eql }
+ *      eql     :       relat { eqrel relat }
+ *      relat   :       shift { rel shift }
+ *      shift   :       primary { shop primary }
+ *      primary :       term { addop term }
+ *      term    :       unary { mulop unary }
+ *      unary   :       factor
+ *              |       unop unary
+ *      factor  :       constant
+ *              |       "(" query ")"
+ *      constant:       num
+ *              |       "'" CHAR "'"
+ *      num     :       DIGIT
+ *              |       DIGIT num
+ *      shop    :       "<<"
+ *              |       ">>"
+ *      eqlrel  :       "="
+ *              |       "=="
+ *              |       "!="
+ *      rel     :       "<"
+ *              |       ">"
+ *              |       "<="
+ *              |       ">="
+ *
+ *
+ *      This expression evaluator is lifted from a public-domain
+ *      C Pre-Processor included with the DECUS C Compiler distribution.
+ *      It is hacked somewhat to be suitable for m4.
+ *
+ *      Originally by:  Mike Lutz
+ *                      Bob Harper
+ */
+
+#define TRUE    1
+#define FALSE   0
+#define EOS     (char) 0
+#define EQL     0
+#define NEQ     1
+#define LSS     2
+#define LEQ     3
+#define GTR     4
+#define GEQ     5
+#define OCTAL   8
+#define DECIMAL 10
+
+static char *nxtch;		       /* Parser scan pointer */
+
+static int query __P((void));
+static int lor __P((void));
+static int land __P((void));
+static int bor __P((void));
+static int bxor __P((void));
+static int band __P((void));
+static int eql __P((void));
+static int relat __P((void));
+static int shift __P((void));
+static int primary __P((void));
+static int term __P((void));
+static int unary __P((void));
+static int factor __P((void));
+static int constant __P((void));
+static int num __P((void));
+static int geteql __P((void));
+static int getrel __P((void));
+static int skipws __P((void));
+static void experr __P((char *));
+
+/*
+ * For longjmp
+ */
+#include <setjmp.h>
+static jmp_buf expjump;
+
+/*
+ * macros:
+ *      ungetch - Put back the last character examined.
+ *      getch   - return the next character from expr string.
+ */
+#define ungetch()       nxtch--
+#define getch()         *nxtch++
+
+int
+expr(expbuf)
+char *expbuf;
+{
+	register int rval;
+
+	nxtch = expbuf;
+	if (setjmp(expjump) != 0)
+		return FALSE;
+
+	rval = query();
+	if (skipws() == EOS)
+		return rval;
+
+	printf("m4: ill-formed expression.\n");
+	return FALSE;
+}
+
+/*
+ * query : lor | lor '?' query ':' query
+ */
+static int
+query()
+{
+	register int bool, true_val, false_val;
+
+	bool = lor();
+	if (skipws() != '?') {
+		ungetch();
+		return bool;
+	}
+
+	true_val = query();
+	if (skipws() != ':')
+		experr("bad query");
+
+	false_val = query();
+	return bool ? true_val : false_val;
+}
+
+/*
+ * lor : land { '||' land }
+ */
+static int
+lor()
+{
+	register int c, vl, vr;
+
+	vl = land();
+	while ((c = skipws()) == '|' && getch() == '|') {
+		vr = land();
+		vl = vl || vr;
+	}
+
+	if (c == '|')
+		ungetch();
+	ungetch();
+	return vl;
+}
+
+/*
+ * land : bor { '&&' bor }
+ */
+static int
+land()
+{
+	register int c, vl, vr;
+
+	vl = bor();
+	while ((c = skipws()) == '&' && getch() == '&') {
+		vr = bor();
+		vl = vl && vr;
+	}
+
+	if (c == '&')
+		ungetch();
+	ungetch();
+	return vl;
+}
+
+/*
+ * bor : bxor { '|' bxor }
+ */
+static int
+bor()
+{
+	register int vl, vr, c;
+
+	vl = bxor();
+	while ((c = skipws()) == '|' && getch() != '|') {
+		ungetch();
+		vr = bxor();
+		vl |= vr;
+	}
+
+	if (c == '|')
+		ungetch();
+	ungetch();
+	return vl;
+}
+
+/*
+ * bxor : band { '^' band }
+ */
+static int
+bxor()
+{
+	register int vl, vr;
+
+	vl = band();
+	while (skipws() == '^') {
+		vr = band();
+		vl ^= vr;
+	}
+
+	ungetch();
+	return vl;
+}
+
+/*
+ * band : eql { '&' eql }
+ */
+static int
+band()
+{
+	register int vl, vr, c;
+
+	vl = eql();
+	while ((c = skipws()) == '&' && getch() != '&') {
+		ungetch();
+		vr = eql();
+		vl &= vr;
+	}
+
+	if (c == '&')
+		ungetch();
+	ungetch();
+	return vl;
+}
+
+/*
+ * eql : relat { eqrel relat }
+ */
+static int
+eql()
+{
+	register int vl, vr, rel;
+
+	vl = relat();
+	while ((rel = geteql()) != -1) {
+		vr = relat();
+
+		switch (rel) {
+
+		case EQL:
+			vl = (vl == vr);
+			break;
+		case NEQ:
+			vl = (vl != vr);
+			break;
+		}
+	}
+	return vl;
+}
+
+/*
+ * relat : shift { rel shift }
+ */
+static int
+relat()
+{
+	register int vl, vr, rel;
+
+	vl = shift();
+	while ((rel = getrel()) != -1) {
+
+		vr = shift();
+		switch (rel) {
+
+		case LEQ:
+			vl = (vl <= vr);
+			break;
+		case LSS:
+			vl = (vl < vr);
+			break;
+		case GTR:
+			vl = (vl > vr);
+			break;
+		case GEQ:
+			vl = (vl >= vr);
+			break;
+		}
+	}
+	return vl;
+}
+
+/*
+ * shift : primary { shop primary }
+ */
+static int
+shift()
+{
+	register int vl, vr, c;
+
+	vl = primary();
+	while (((c = skipws()) == '<' || c == '>') && c == getch()) {
+		vr = primary();
+
+		if (c == '<')
+			vl <<= vr;
+		else
+			vl >>= vr;
+	}
+
+	if (c == '<' || c == '>')
+		ungetch();
+	ungetch();
+	return vl;
+}
+
+/*
+ * primary : term { addop term }
+ */
+static int
+primary()
+{
+	register int c, vl, vr;
+
+	vl = term();
+	while ((c = skipws()) == '+' || c == '-') {
+		vr = term();
+		if (c == '+')
+			vl += vr;
+		else
+			vl -= vr;
+	}
+
+	ungetch();
+	return vl;
+}
+
+/*
+ * <term> := <unary> { <mulop> <unary> }
+ */
+static int
+term()
+{
+	register int c, vl, vr;
+
+	vl = unary();
+	while ((c = skipws()) == '*' || c == '/' || c == '%') {
+		vr = unary();
+
+		switch (c) {
+		case '*':
+			vl *= vr;
+			break;
+		case '/':
+			vl /= vr;
+			break;
+		case '%':
+			vl %= vr;
+			break;
+		}
+	}
+	ungetch();
+	return vl;
+}
+
+/*
+ * unary : factor | unop unary
+ */
+static int
+unary()
+{
+	register int val, c;
+
+	if ((c = skipws()) == '!' || c == '~' || c == '-') {
+		val = unary();
+
+		switch (c) {
+		case '!':
+			return !val;
+		case '~':
+			return ~val;
+		case '-':
+			return -val;
+		}
+	}
+
+	ungetch();
+	return factor();
+}
+
+/*
+ * factor : constant | '(' query ')'
+ */
+static int
+factor()
+{
+	register int val;
+
+	if (skipws() == '(') {
+		val = query();
+		if (skipws() != ')')
+			experr("bad factor");
+		return val;
+	}
+
+	ungetch();
+	return constant();
+}
+
+/*
+ * constant: num | 'char'
+ * Note: constant() handles multi-byte constants
+ */
+static int
+constant()
+{
+	register int i;
+	register int value;
+	register char c;
+	int v[sizeof(int)];
+
+	if (skipws() != '\'') {
+		ungetch();
+		return num();
+	}
+	for (i = 0; i < sizeof(int); i++) {
+		if ((c = getch()) == '\'') {
+			ungetch();
+			break;
+		}
+		if (c == '\\') {
+			switch (c = getch()) {
+			case '0':
+			case '1':
+			case '2':
+			case '3':
+			case '4':
+			case '5':
+			case '6':
+			case '7':
+				ungetch();
+				c = num();
+				break;
+			case 'n':
+				c = 012;
+				break;
+			case 'r':
+				c = 015;
+				break;
+			case 't':
+				c = 011;
+				break;
+			case 'b':
+				c = 010;
+				break;
+			case 'f':
+				c = 014;
+				break;
+			}
+		}
+		v[i] = c;
+	}
+	if (i == 0 || getch() != '\'')
+		experr("illegal character constant");
+	for (value = 0; --i >= 0;) {
+		value <<= 8;
+		value += v[i];
+	}
+	return value;
+}
+
+/*
+ * num : digit | num digit
+ */
+static int
+num()
+{
+	register int rval, c, base;
+	int ndig;
+
+	base = ((c = skipws()) == '0') ? OCTAL : DECIMAL;
+	rval = 0;
+	ndig = 0;
+	while (c >= '0' && c <= (base == OCTAL ? '7' : '9')) {
+		rval *= base;
+		rval += (c - '0');
+		c = getch();
+		ndig++;
+	}
+	ungetch();
+	
+	if (ndig == 0)
+		experr("bad constant");
+	
+	return rval;
+
+}
+
+/*
+ * eqlrel : '=' | '==' | '!='
+ */
+static int
+geteql()
+{
+	register int c1, c2;
+
+	c1 = skipws();
+	c2 = getch();
+
+	switch (c1) {
+
+	case '=':
+		if (c2 != '=')
+			ungetch();
+		return EQL;
+
+	case '!':
+		if (c2 == '=')
+			return NEQ;
+		ungetch();
+		ungetch();
+		return -1;
+
+	default:
+		ungetch();
+		ungetch();
+		return -1;
+	}
+}
+
+/*
+ * rel : '<' | '>' | '<=' | '>='
+ */
+static int
+getrel()
+{
+	register int c1, c2;
+
+	c1 = skipws();
+	c2 = getch();
+
+	switch (c1) {
+
+	case '<':
+		if (c2 == '=')
+			return LEQ;
+		ungetch();
+		return LSS;
+
+	case '>':
+		if (c2 == '=')
+			return GEQ;
+		ungetch();
+		return GTR;
+
+	default:
+		ungetch();
+		ungetch();
+		return -1;
+	}
+}
+
+/*
+ * Skip over any white space and return terminating char.
+ */
+static int
+skipws()
+{
+	register char c;
+
+	while ((c = getch()) <= ' ' && c > EOS)
+		;
+	return c;
+}
+
+/*
+ * resets environment to eval(), prints an error 
+ * and forces eval to return FALSE.
+ */
+static void
+experr(msg)
+char *msg;
+{
+	printf("m4: %s in expr.\n", msg);
+	longjmp(expjump, -1);
+}