intprops: add double-inclusion guard

* lib/intprops.h: Allow idempotent includes.
Suggested by Bruce Korb.

Signed-off-by: Eric Blake <ebb9@byu.net>

diff --git a/ChangeLog b/ChangeLog
index 5c8f1b68df64b53bd0b41cceacfa5a71fc2bbd14..4ff76e75bd71b7e257c8d5b87467c9381d3585c4 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2009-11-14  Eric Blake  <ebb9@byu.net>
 
+       intprops: add double-inclusion guard
+       * lib/intprops.h: Allow idempotent includes.
+       Suggested by Bruce Korb.
+
        openat: detect Solaris fchownat bug
        * lib/fchownat.c (rpl_fchownat): Work around Solaris bug.  Avoid
        penalizing glibc chownat when only lchownat is broken.

diff --git a/lib/intprops.h b/lib/intprops.h
index 002161ee57402c4ee89ca7a5da20d4bfbc7858ae..325c3979972abcf2403b36260d765a4bcbae5df1 100644 (file)
--- a/lib/intprops.h
+++ b/lib/intprops.h
@@ -1,6 +1,7 @@
 /* intprops.h -- properties of integer types
 
-   Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2009 Free Software
+   Foundation, Inc.
 
    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
@@ -17,37 +18,40 @@
 
 /* Written by Paul Eggert.  */
 
-#include <limits.h>
+#ifndef GL_INTPROPS_H
+# define GL_INTPROPS_H
+
+# include <limits.h>
 
 /* The extra casts in the following macros work around compiler bugs,
    e.g., in Cray C 5.0.3.0.  */
 
 /* True if the arithmetic type T is an integer type.  bool counts as
    an integer.  */
-#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
+# define TYPE_IS_INTEGER(t) ((t) 1.5 == 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)
+# 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))
+# 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.
    If this is a problem for you, please let us know how to fix it for
    your host.  */
-#define TYPE_MINIMUM(t) \
+# 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) \
+# define TYPE_MAXIMUM(t) \
   ((t) (! TYPE_SIGNED (t) \
        ? (t) -1 \
        : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))
@@ -58,20 +62,22 @@
    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
+# 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) \
+# define INT_STRLEN_BOUND(t) \
   ((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 type or expression T,
    including the terminating null.  */
-#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
+# define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
+
+#endif /* GL_INTPROPS_H */