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[gnulib.git] / lib / intprops.h

diff --git a/lib/intprops.h b/lib/intprops.h
index 5c14397..002161e 100644 (file)
--- a/lib/intprops.h
+++ b/lib/intprops.h
@@ -2,10 +2,10 @@
 
    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
@@ -13,8 +13,7 @@
    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.  */
 
@@ -28,7 +27,7 @@
 #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
 
 /* True if negative values of the signed integer type T use two's
-   complement, one's complement, or signed magnitude representation,
+   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)
@@ -53,13 +52,26 @@
        ? (t) -1 \
        : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
 
-/* Bound on length of the string representing an integer value of type T.
-   Subtract 1 for the sign bit if t is signed; log10 (2.0) < 146/485;
+/* 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 of 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)