Expr fixes

[Followups to -standards, please.]

I've fixed expr to be able to deal correctly with arguments and
results consisting of a single '-'.  At the same time, I also changed
the data type used internally by expr to intmax_t, away from
(deprecated) quad_t.  The whole ``pre-parse to see if it might be an
integer'' thing is silly, and should probably be removed entirely --
function calls are *not* that expensive.  There are many style bugs in
this utility.

I have a couple of defect reports in to the Austin Group about the
lack of specificity in 1003.1-2001 as regards how expr's integer math
actually works, and whether expr should be prepared to accept an
initial argument of "--" to indicate that there are no options.

This change was created and tested on FreeBSD/sparc64, while tracking
down a test-suite failure in autoconf 2.52.

-GAWollman

Index: expr.y
===================================================================
RCS file: /home/cvs/src/bin/expr/expr.y,v
retrieving revision 1.18
diff -u -r1.18 expr.y
--- expr.y	2002/02/02 06:36:49	1.18
+++ expr.y	2002/03/22 00:47:57
@@ -9,6 +9,7 @@
 
 #include <sys/types.h>
 #include <stdio.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #include <string.h>
 #include <locale.h>
@@ -26,20 +27,20 @@
 	enum valtype type;
 	union {
 		char *s;
-		quad_t i;
+		intmax_t i;
 	} u;
 } ;
 
 struct val *result;
 
-int		chk_div(quad_t, quad_t);
-int		chk_minus(quad_t, quad_t, quad_t);
-int		chk_plus(quad_t, quad_t, quad_t);
-int		chk_times(quad_t, quad_t, quad_t);
+int		chk_div(intmax_t, intmax_t);
+int		chk_minus(intmax_t, intmax_t, intmax_t);
+int		chk_plus(intmax_t, intmax_t, intmax_t);
+int		chk_times(intmax_t, intmax_t, intmax_t);
 void		free_value(struct val *);
 int		is_zero_or_null(struct val *);
 int		isstring(struct val *);
-struct val	*make_integer(quad_t);
+struct val	*make_integer(intmax_t);
 struct val	*make_str(const char *);
 struct val	*op_and(struct val *, struct val *);
 struct val	*op_colon(struct val *, struct val *);
@@ -55,7 +56,7 @@
 struct val	*op_plus(struct val *, struct val *);
 struct val	*op_rem(struct val *, struct val *);
 struct val	*op_times(struct val *, struct val *);
-quad_t		to_integer(struct val *);
+intmax_t	to_integer(struct val *);
 void		to_string(struct val *);
 int		yyerror(const char *);
 int		yylex(void);
@@ -105,7 +106,7 @@
 %%
 
 struct val *
-make_integer(quad_t i)
+make_integer(intmax_t i)
 {
 	struct val *vp;
 
@@ -123,26 +124,34 @@
 make_str(const char *s)
 {
 	struct val *vp;
-	size_t i;
-	int isint;
+	char *ep;
 
 	vp = (struct val *) malloc (sizeof (*vp));
 	if (vp == NULL || ((vp->u.s = strdup (s)) == NULL)) {
 		errx (2, "malloc() failed");
 	}
 
-	for(i = 1, isint = isdigit(s[0]) || s[0] == '-';
-	    isint && i < strlen(s);
-	    i++)
-	{
-		if(!isdigit(s[i]))
-			 isint = 0;
-	}
+	/*
+	 * Previously we tried to scan the string to see if it ``looked like''
+	 * an integer (erroneously, as it happened).  Let strtoimax() do the
+	 * dirty work.  We could cache the value, except that we are using
+	 * a union and need to preserve the original string form until we
+	 * are certain that it is not needed.
+	 *
+	 * IEEE Std.1003.1-2001 says:
+	 * /integer/ An argument consisting only of an (optional) unary minus  
+	 *	     followed by digits.          
+	 *
+	 * This means that arguments which consist of digits followed by
+	 * non-digits MUST NOT be considered integers.  strtoimax() will
+	 * figure this out for us.
+	 */
+	(void)strtoimax(s, &ep, 10);
 
-	if (isint)
-		vp->type = numeric_string;
-	else	
+	if (*ep != '\0')
 		vp->type = string;
+	else	
+		vp->type = numeric_string;
 
 	return vp;
 }
@@ -156,10 +165,10 @@
 }
 
 
-quad_t
+intmax_t
 to_integer(struct val *vp)
 {
-	quad_t i;
+	intmax_t i;
 
 	if (vp->type == integer)
 		return 1;
@@ -169,10 +178,10 @@
 
 	/* vp->type == numeric_string, make it numeric */
 	errno = 0;
-	i  = strtoq(vp->u.s, (char**)NULL, 10);
-	if (errno != 0) {
-		errx (2, "overflow");
-	}
+	i  = strtoimax(vp->u.s, (char **)NULL, 10);
+	if (errno == ERANGE)
+		err(2, NULL);
+
 	free (vp->u.s);
 	vp->u.i = i;
 	vp->type = integer;
@@ -187,12 +196,18 @@
 	if (vp->type == string || vp->type == numeric_string)
 		return;
 
-	tmp = malloc ((size_t)25);
+	/*
+	 * log_10(x) ~= 0.3 * log_2(x).  Rounding up gives the number
+	 * of digits; add one each for the sign and terminating null
+	 * character, respectively.
+	 */
+#define	NDIGITS(x) (3 * (sizeof(x) * CHAR_BIT) / 10 + 1 + 1 + 1)
+	tmp = malloc (NDIGITS(vp->u.i));
 	if (tmp == NULL) {
 		errx (2, "malloc() failed");
 	}
 
-	sprintf (tmp, "%lld", (long long)vp->u.i);
+	sprintf (tmp, "%jd", vp->u.i);
 	vp->type = string;
 	vp->u.s  = tmp;
 }
@@ -252,7 +267,7 @@
 	yyparse ();
 
 	if (result->type == integer)
-		printf ("%lld\n", (long long)result->u.i);
+		printf ("%jd\n", result->u.i);
 	else
 		printf ("%s\n", result->u.s);
 
@@ -284,7 +299,7 @@
 	if (is_zero_or_null (a) || is_zero_or_null (b)) {
 		free_value (a);
 		free_value (b);
-		return (make_integer ((quad_t)0));
+		return (make_integer ((intmax_t)0));
 	} else {
 		free_value (b);
 		return (a);
@@ -299,11 +314,11 @@
 	if (isstring (a) || isstring (b)) {
 		to_string (a);
 		to_string (b);	
-		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) == 0));
+		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) == 0));
 	} else {
 		(void)to_integer(a);
 		(void)to_integer(b);
-		r = make_integer ((quad_t)(a->u.i == b->u.i));
+		r = make_integer ((intmax_t)(a->u.i == b->u.i));
 	}
 
 	free_value (a);
@@ -319,11 +334,11 @@
 	if (isstring (a) || isstring (b)) {
 		to_string (a);
 		to_string (b);
-		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) > 0));
+		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) > 0));
 	} else {
 		(void)to_integer(a);
 		(void)to_integer(b);
-		r = make_integer ((quad_t)(a->u.i > b->u.i));
+		r = make_integer ((intmax_t)(a->u.i > b->u.i));
 	}
 
 	free_value (a);
@@ -339,11 +354,11 @@
 	if (isstring (a) || isstring (b)) {
 		to_string (a);
 		to_string (b);
-		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) < 0));
+		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) < 0));
 	} else {
 		(void)to_integer(a);
 		(void)to_integer(b);
-		r = make_integer ((quad_t)(a->u.i < b->u.i));
+		r = make_integer ((intmax_t)(a->u.i < b->u.i));
 	}
 
 	free_value (a);
@@ -359,11 +374,11 @@
 	if (isstring (a) || isstring (b)) {
 		to_string (a);
 		to_string (b);
-		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) >= 0));
+		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) >= 0));
 	} else {
 		(void)to_integer(a);
 		(void)to_integer(b);
-		r = make_integer ((quad_t)(a->u.i >= b->u.i));
+		r = make_integer ((intmax_t)(a->u.i >= b->u.i));
 	}
 
 	free_value (a);
@@ -379,11 +394,11 @@
 	if (isstring (a) || isstring (b)) {
 		to_string (a);
 		to_string (b);
-		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) <= 0));
+		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) <= 0));
 	} else {
 		(void)to_integer(a);
 		(void)to_integer(b);
-		r = make_integer ((quad_t)(a->u.i <= b->u.i));
+		r = make_integer ((intmax_t)(a->u.i <= b->u.i));
 	}
 
 	free_value (a);
@@ -399,11 +414,11 @@
 	if (isstring (a) || isstring (b)) {
 		to_string (a);
 		to_string (b);
-		r = make_integer ((quad_t)(strcoll (a->u.s, b->u.s) != 0));
+		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) != 0));
 	} else {
 		(void)to_integer(a);
 		(void)to_integer(b);
-		r = make_integer ((quad_t)(a->u.i != b->u.i));
+		r = make_integer ((intmax_t)(a->u.i != b->u.i));
 	}
 
 	free_value (a);
@@ -412,7 +427,7 @@
 }
 
 int
-chk_plus(quad_t a, quad_t b, quad_t r)
+chk_plus(intmax_t a, intmax_t b, intmax_t r)
 {
 	/* sum of two positive numbers must be positive */
 	if (a > 0 && b > 0 && r <= 0)
@@ -433,7 +448,7 @@
 		errx (2, "non-numeric argument");
 	}
 
-	r = make_integer (/*(quad_t)*/(a->u.i + b->u.i));
+	r = make_integer (/*(intmax_t)*/(a->u.i + b->u.i));
 	if (chk_plus (a->u.i, b->u.i, r->u.i)) {
 		errx (2, "overflow");
 	}
@@ -443,16 +458,16 @@
 }
 
 int
-chk_minus(quad_t a, quad_t b, quad_t r)
+chk_minus(intmax_t a, intmax_t b, intmax_t r)
 {
-	/* special case subtraction of QUAD_MIN */
-	if (b == QUAD_MIN) {
+	/* special case subtraction of INTMAX_MIN */
+	if (b == INTMAX_MIN) {
 		if (a >= 0)
 			return 1;
 		else
 			return 0;
 	}
-	/* this is allowed for b != QUAD_MIN */
+	/* this is allowed for b != INTMAX_MIN */
 	return chk_plus (a, -b, r);
 }
 
@@ -465,7 +480,7 @@
 		errx (2, "non-numeric argument");
 	}
 
-	r = make_integer (/*(quad_t)*/(a->u.i - b->u.i));
+	r = make_integer (/*(intmax_t)*/(a->u.i - b->u.i));
 	if (chk_minus (a->u.i, b->u.i, r->u.i)) {
 		errx (2, "overflow");
 	}
@@ -475,7 +490,7 @@
 }
 
 int
-chk_times(quad_t a, quad_t b, quad_t r)
+chk_times(intmax_t a, intmax_t b, intmax_t r)
 {
 	/* special case: first operand is 0, no overflow possible */
 	if (a == 0)
@@ -495,7 +510,7 @@
 		errx (2, "non-numeric argument");
 	}
 
-	r = make_integer (/*(quad_t)*/(a->u.i * b->u.i));
+	r = make_integer (/*(intmax_t)*/(a->u.i * b->u.i));
 	if (chk_times (a->u.i, b->u.i, r->u.i)) {
 		errx (2, "overflow");
 	}
@@ -505,11 +520,11 @@
 }
 
 int
-chk_div(quad_t a, quad_t b)
+chk_div(intmax_t a, intmax_t b)
 {
 	/* div by zero has been taken care of before */
-	/* only QUAD_MIN / -1 causes overflow */
-	if (a == QUAD_MIN && b == -1)
+	/* only INTMAX_MIN / -1 causes overflow */
+	if (a == INTMAX_MIN && b == -1)
 		return 1;
 	/* everything else is OK */
 	return 0;
@@ -528,7 +543,7 @@
 		errx (2, "division by zero");
 	}
 
-	r = make_integer (/*(quad_t)*/(a->u.i / b->u.i));
+	r = make_integer (/*(intmax_t)*/(a->u.i / b->u.i));
 	if (chk_div (a->u.i, b->u.i)) {
 		errx (2, "overflow");
 	}
@@ -550,7 +565,7 @@
 		errx (2, "division by zero");
 	}
 
-	r = make_integer (/*(quad_t)*/(a->u.i % b->u.i));
+	r = make_integer (/*(intmax_t)*/(a->u.i % b->u.i));
 	/* chk_rem necessary ??? */
 	free_value (a);
 	free_value (b);
@@ -584,11 +599,11 @@
 			v = make_str (a->u.s + rm[1].rm_so);
 
 		} else {
-			v = make_integer ((quad_t)(rm[0].rm_eo - rm[0].rm_so));
+			v = make_integer ((intmax_t)(rm[0].rm_eo - rm[0].rm_so));
 		}
 	} else {
 		if (rp.re_nsub == 0) {
-			v = make_integer ((quad_t)0);
+			v = make_integer ((intmax_t)0);
 		} else {
 			v = make_str ("");
 		}

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