Make /bin/expr support 64bit numeric range and range checks by default,

again. This brings back the behaviour of expr in FreeBSD-4, which had been
reverted due to an assumed incompatbility with POSIX.1 for FreeBSD-5.

This issue has been discussed in the freebsd-standards list, and the
consensus was, that POSIX.1 is in fact not violated by this extension,
since it affects only cases of POSIX undefined behaviour (overflow of
signed long).

Other operating systems did upgrade their versions of expr to support
64bit range, after it had been initially brought to FreeBSD. They have
used it for a decade without problems, meanwhile.

The -e option is retained, but it will only select less strict checking
of numeric parameters (leading white-space, leading "+" are allowed and
skipped, an empty string is considered to represent 0 in numeric context.)
The call of check_utility_compat() as a means of establishing backwards
compatibility with FreeBSD-4 is considered obsolete, but preserved in
this commit. It is expected to be removed in a later revision of this
file.
Reviewed by:	bde, das, jilles
MFC after:	2 month (those parts that do not violate POLA)

1 files changed, 95 insertions, 115 deletions

diff --git a/bin/expr/expr.y b/bin/expr/expr.y
index 356bac294d62..a7f38f5898f5 100644
--- a/bin/expr/expr.y
+++ b/bin/expr/expr.y
@@ -42,13 +42,15 @@ struct val {
 
 struct val *result;
 
+void		assert_to_integer(struct val *);
 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		is_integer(const char *);
 int		isstring(struct val *);
+int		is_zero_or_null(struct val *);
 struct val	*make_integer(intmax_t);
 struct val	*make_str(const char *);
 struct val	*op_and(struct val *, struct val *);
@@ -65,13 +67,13 @@ struct val	*op_or(struct val *, struct val *);
 struct val	*op_plus(struct val *, struct val *);
 struct val	*op_rem(struct val *, struct val *);
 struct val	*op_times(struct val *, struct val *);
-intmax_t	to_integer(struct val *);
+int		to_integer(struct val *);
 void		to_string(struct val *);
 int		yyerror(const char *);
 int		yylex(void);
 int		yyparse(void);
 
-static int	eflag;
+static int	nonposix;
 char **av;
 %}
 
@@ -134,37 +136,16 @@ struct val *
 make_str(const char *s)
 {
 	struct val *vp;
-	char *ep;
 
 	vp = (struct val *) malloc (sizeof (*vp));
 	if (vp == NULL || ((vp->u.s = strdup (s)) == NULL)) {
 		errx(ERR_EXIT, "malloc() failed");
 	}
 
-	/*
-	 * 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.
-	 */
-	if (eflag)
-		(void)strtoimax(s, &ep, 10);
+	if (is_integer(s))
+		vp->type = numeric_string;
 	else
-		(void)strtol(s, &ep, 10);
-
-	if (*ep != '\0')
 		vp->type = string;
-	else	
-		vp->type = numeric_string;
 
 	return vp;
 }
@@ -178,31 +159,33 @@ free_value(struct val *vp)
 }
 
 
-intmax_t
+int
 to_integer(struct val *vp)
 {
 	intmax_t i;
 
-	if (vp->type == integer)
-		return 1;
-
-	if (vp->type == string)
-		return 0;
-
-	/* vp->type == numeric_string, make it numeric */
-	errno = 0;
-	if (eflag) {
+	/* we can only convert numeric_string to integer, here */
+	if (vp->type == numeric_string) {
+		errno = 0;
 		i  = strtoimax(vp->u.s, (char **)NULL, 10);
-		if (errno == ERANGE)
-			err(ERR_EXIT, NULL);
-	} else {
-		i = strtol(vp->u.s, (char **)NULL, 10);
+		/* just keep as numeric_string, if the conversion fails */
+		if (errno != ERANGE) {
+			free (vp->u.s);
+			vp->u.i = i;
+			vp->type = integer;
+		}
 	}
+	return (vp->type == integer);
+}
 
-	free (vp->u.s);
-	vp->u.i = i;
-	vp->type = integer;
-	return 1;
+
+void
+assert_to_integer(struct val *vp)
+{
+	if (vp->type == string)
+		errx(ERR_EXIT, "not a decimal number: '%s'", vp->u.s);
+	if (!to_integer(vp))
+		errx(ERR_EXIT, "operand too large: '%s'", vp->u.s);
 }
 
 void
@@ -230,6 +213,25 @@ to_string(struct val *vp)
 
 
 int
+is_integer(const char *s)
+{
+	if (nonposix) {
+		if (*s == '\0')
+			return (1);
+		while (isspace((unsigned char)*s))
+			s++;
+	}
+	if (*s == '-' || (nonposix && *s == '+'))
+		s++;
+	if (*s == '\0')
+		return (0);
+	while (isdigit((unsigned char)*s))
+		s++;
+	return (*s == '\0');
+}
+
+
+int
 isstring(struct val *vp)
 {
 	/* only TRUE if this string is not a valid integer */
@@ -282,12 +284,12 @@ main(int argc, char *argv[])
 	if (getenv("EXPR_COMPAT") != NULL
 	    || check_utility_compat("expr")) {
 		av = argv + 1;
-		eflag = 1;
+		nonposix = 1;
 	} else {
 		while ((c = getopt(argc, argv, "e")) != -1)
 			switch (c) {
 			case 'e':
-				eflag = 1;
+				nonposix = 1;
 				break;
 
 			default:
@@ -318,15 +320,17 @@ yyerror(const char *s __unused)
 struct val *
 op_or(struct val *a, struct val *b)
 {
-	if (is_zero_or_null (a)) {
-		free_value (a);
-		return (b);
-	} else {
-		free_value (b);
+	if (!is_zero_or_null(a)) {
+		free_value(b);
 		return (a);
 	}
+	free_value(a);
+	if (!is_zero_or_null(b))
+		return (b);
+	free_value(b);
+	return (make_integer((intmax_t)0));
 }
-		
+
 struct val *
 op_and(struct val *a, struct val *b)
 {
@@ -350,8 +354,8 @@ op_eq(struct val *a, struct val *b)
 		to_string (b);	
 		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) == 0));
 	} else {
-		(void)to_integer(a);
-		(void)to_integer(b);
+		assert_to_integer(a);
+		assert_to_integer(b);
 		r = make_integer ((intmax_t)(a->u.i == b->u.i));
 	}
 
@@ -370,8 +374,8 @@ op_gt(struct val *a, struct val *b)
 		to_string (b);
 		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) > 0));
 	} else {
-		(void)to_integer(a);
-		(void)to_integer(b);
+		assert_to_integer(a);
+		assert_to_integer(b);
 		r = make_integer ((intmax_t)(a->u.i > b->u.i));
 	}
 
@@ -390,8 +394,8 @@ op_lt(struct val *a, struct val *b)
 		to_string (b);
 		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) < 0));
 	} else {
-		(void)to_integer(a);
-		(void)to_integer(b);
+		assert_to_integer(a);
+		assert_to_integer(b);
 		r = make_integer ((intmax_t)(a->u.i < b->u.i));
 	}
 
@@ -410,8 +414,8 @@ op_ge(struct val *a, struct val *b)
 		to_string (b);
 		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) >= 0));
 	} else {
-		(void)to_integer(a);
-		(void)to_integer(b);
+		assert_to_integer(a);
+		assert_to_integer(b);
 		r = make_integer ((intmax_t)(a->u.i >= b->u.i));
 	}
 
@@ -430,8 +434,8 @@ op_le(struct val *a, struct val *b)
 		to_string (b);
 		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) <= 0));
 	} else {
-		(void)to_integer(a);
-		(void)to_integer(b);
+		assert_to_integer(a);
+		assert_to_integer(b);
 		r = make_integer ((intmax_t)(a->u.i <= b->u.i));
 	}
 
@@ -450,8 +454,8 @@ op_ne(struct val *a, struct val *b)
 		to_string (b);
 		r = make_integer ((intmax_t)(strcoll (a->u.s, b->u.s) != 0));
 	} else {
-		(void)to_integer(a);
-		(void)to_integer(b);
+		assert_to_integer(a);
+		assert_to_integer(b);
 		r = make_integer ((intmax_t)(a->u.i != b->u.i));
 	}
 
@@ -479,17 +483,13 @@ op_plus(struct val *a, struct val *b)
 {
 	struct val *r;
 
-	if (!to_integer(a) || !to_integer(b)) {
-		errx(ERR_EXIT, "non-numeric argument");
-	}
+	assert_to_integer(a);
+	assert_to_integer(b);
 
-	if (eflag) {
-		r = make_integer(a->u.i + b->u.i);
-		if (chk_plus(a->u.i, b->u.i, r->u.i)) {
-			errx(ERR_EXIT, "overflow");
-		}
-	} else
-		r = make_integer((long)a->u.i + (long)b->u.i);
+	r = make_integer(a->u.i + b->u.i);
+	if (chk_plus(a->u.i, b->u.i, r->u.i)) {
+		errx(ERR_EXIT, "overflow");
+	}
 
 	free_value (a);
 	free_value (b);
@@ -516,17 +516,13 @@ op_minus(struct val *a, struct val *b)
 {
 	struct val *r;
 
-	if (!to_integer(a) || !to_integer(b)) {
-		errx(ERR_EXIT, "non-numeric argument");
-	}
+	assert_to_integer(a);
+	assert_to_integer(b);
 
-	if (eflag) {
-		r = make_integer(a->u.i - b->u.i);
-		if (chk_minus(a->u.i, b->u.i, r->u.i)) {
-			errx(ERR_EXIT, "overflow");
-		}
-	} else
-		r = make_integer((long)a->u.i - (long)b->u.i);
+	r = make_integer(a->u.i - b->u.i);
+	if (chk_minus(a->u.i, b->u.i, r->u.i)) {
+		errx(ERR_EXIT, "overflow");
+	}
 
 	free_value (a);
 	free_value (b);
@@ -550,17 +546,13 @@ op_times(struct val *a, struct val *b)
 {
 	struct val *r;
 
-	if (!to_integer(a) || !to_integer(b)) {
-		errx(ERR_EXIT, "non-numeric argument");
-	}
+	assert_to_integer(a);
+	assert_to_integer(b);
 
-	if (eflag) {
-		r = make_integer(a->u.i * b->u.i);
-		if (chk_times(a->u.i, b->u.i, r->u.i)) {
-			errx(ERR_EXIT, "overflow");
-		}
-	} else
-		r = make_integer((long)a->u.i * (long)b->u.i);
+	r = make_integer(a->u.i * b->u.i);
+	if (chk_times(a->u.i, b->u.i, r->u.i)) {
+		errx(ERR_EXIT, "overflow");
+	}
 
 	free_value (a);
 	free_value (b);
@@ -583,21 +575,16 @@ op_div(struct val *a, struct val *b)
 {
 	struct val *r;
 
-	if (!to_integer(a) || !to_integer(b)) {
-		errx(ERR_EXIT, "non-numeric argument");
-	}
+	assert_to_integer(a);
+	assert_to_integer(b);
 
 	if (b->u.i == 0) {
 		errx(ERR_EXIT, "division by zero");
 	}
-
-	if (eflag) {
-		r = make_integer(a->u.i / b->u.i);
-		if (chk_div(a->u.i, b->u.i)) {
-			errx(ERR_EXIT, "overflow");
-		}
-	} else
-		r = make_integer((long)a->u.i / (long)b->u.i);
+	if (chk_div(a->u.i, b->u.i)) {
+		errx(ERR_EXIT, "overflow");
+	}
+	r = make_integer(a->u.i / b->u.i);
 
 	free_value (a);
 	free_value (b);
@@ -609,19 +596,12 @@ op_rem(struct val *a, struct val *b)
 {
 	struct val *r;
 
-	if (!to_integer(a) || !to_integer(b)) {
-		errx(ERR_EXIT, "non-numeric argument");
-	}
-
+	assert_to_integer(a);
+	assert_to_integer(b);
 	if (b->u.i == 0) {
 		errx(ERR_EXIT, "division by zero");
 	}
-
-	if (eflag)
-		r = make_integer(a->u.i % b->u.i);
-	        /* chk_rem necessary ??? */
-	else
-		r = make_integer((long)a->u.i % (long)b->u.i);
+	r = make_integer(a->u.i % b->u.i);
 
 	free_value (a);
 	free_value (b);