Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This program 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 Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Paul Eggert. */
an integer. */
#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
-/* True if negative values of the integer type T use twos complement
- representation. */
-#define TYPE_TWOS_COMPLEMENT(t) ((t) - (t) 1 == (t) ((t) ~ (t) 1 + (t) 1))
+/* True if negative values of the signed integer type T use two's
+ complement, ones' complement, or signed magnitude representation,
+ respectively. Much GNU code assumes two's complement, but some
+ people like to be portable to all possible C hosts. */
+#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
+#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
+#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
/* True if the arithmetic type T is signed. */
#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
/* The maximum and minimum values for the integer type T. These
- macros have undefined behavior if T is signed and has padding bits
- (i.e., bits that do not contribute to the value), or if T uses
- signed-magnitude representation. If this is a problem for you,
- please let us know how to fix it for your host. */
-#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
- ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
-#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
-
-/* Bound on length of the string representing an integer value or type T.
- Subtract 1 for the sign bit if t is signed; log10 (2.0) < 146/485;
+ macros have undefined behavior if T is signed and has padding bits.
+ If this is a problem for you, please let us know how to fix it for
+ your host. */
+#define TYPE_MINIMUM(t) \
+ ((t) (! TYPE_SIGNED (t) \
+ ? (t) 0 \
+ : TYPE_SIGNED_MAGNITUDE (t) \
+ ? ~ (t) 0 \
+ : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))
+#define TYPE_MAXIMUM(t) \
+ ((t) (! TYPE_SIGNED (t) \
+ ? (t) -1 \
+ : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
+
+/* Return zero if T can be determined to be an unsigned type.
+ Otherwise, return 1.
+ When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a
+ tighter bound. Otherwise, it overestimates the true bound by one byte
+ when applied to unsigned types of size 2, 4, 16, ... bytes.
+ The symbol signed_type_or_expr__ is private to this header file. */
+#if __GNUC__ >= 2
+# define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t))
+#else
+# define signed_type_or_expr__(t) 1
+#endif
+
+/* Bound on length of the string representing an integer type or expression T.
+ Subtract 1 for the sign bit if T is signed; log10 (2.0) < 146/485;
add 1 for integer division truncation; add 1 more for a minus sign
if needed. */
#define INT_STRLEN_BOUND(t) \
- ((sizeof (t) * CHAR_BIT - 1) * 146 / 485 + 2)
+ ((sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) * 146 / 485 \
+ + signed_type_or_expr__ (t) + 1)
-/* Bound on buffer size needed to represent an integer value or type T,
+/* Bound on buffer size needed to represent an integer type or expression T,
including the terminating null. */
#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
projects / gnulib.git / blobdiff