Re: intprops.h needs multi-inclusion guard

[Eric Blake]

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According to Bruce Korb on 11/14/2009 12:15 PM:
> In file included from ../lib/inttostr.h:24,
>                  from shar.c:140:
> ../lib/intprops.h:44:1: warning: "TYPE_MINIMUM" redefined
> shar.c:108:1: warning: this is the location of the previous definition
> ../lib/intprops.h:50:1: warning: "TYPE_MAXIMUM" redefined
> shar.c:113:1: warning: this is the location of the previous definition

A multi-inclusion guard won't help you with this error; your duplicate
definition comes because shar.c is blindly redefining the macro with
slightly different spelling rather than relying on intprops.h.  But I
don't see the harm in adding it, so I'm committing:

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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>From fdac57e87e1ba42f9ed516f0b6b828e4522719bb Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Sat, 14 Nov 2009 15:09:08 -0700
Subject: [PATCH] intprops: add double-inclusion guard

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

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog      |    4 ++++
 lib/intprops.h |   38 ++++++++++++++++++++++----------------
 2 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 5c8f1b6..4ff76e7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2009-11-14  Eric Blake  <address@hidden>

+       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 002161e..325c397 100644
--- 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 */
-- 
1.6.5.rc1