xalloc.h, system.h changes for X2REALLOC etc.

[Paul Eggert]

When merging from gnulib I discovered I'm still a bit at sea about
what to do about the X2REALLOC and X2NREALLOC macros; instead of
thinking it through I thought it best for now to revert xalloc.h to
gnulib and move the new stuff to src/system.h.  I installed this:

2005-09-21  Paul Eggert  <address@hidden>

        * lib/xalloc.h (VERIFY_EXPR, X2NREALLOC, X2REALLOC): Remove.
        The latter two macros are moving to ../src/system.h for now.
        This reverts this file to the gnulib version.
        * src/system.h (X2NREALLOC, X2REALLOC): Moved here from
        ../lib/xalloc.h, with args properly parenthesized, and using
        verify_expr rather than the old VERIFY_EXPR.

Index: lib/xalloc.h
===================================================================
RCS file: /fetish/cu/lib/xalloc.h,v
retrieving revision 1.32
diff -p -u -r1.32 xalloc.h
--- lib/xalloc.h        13 Sep 2005 21:11:25 -0000      1.32
+++ lib/xalloc.h        22 Sep 2005 06:24:28 -0000
@@ -1,7 +1,7 @@
 /* xalloc.h -- malloc with out-of-memory checking
 
    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2003, 2004, 2005 Free Software Foundation, Inc.
+   1999, 2000, 2003, 2004 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
@@ -56,24 +56,6 @@ void *x2nrealloc (void *p, size_t *pn, s
 void *xmemdup (void const *p, size_t s);
 char *xstrdup (char const *str);
 
-/* Verify a requirement at compile-time (unlike assert, which is runtime).  */
-# undef VERIFY_EXPR
-# define VERIFY_EXPR(assertion) \
-   (void)((struct {char a[(assertion) ? 1 : -1]; } *) 0)
-
-/* This is simply a shorthand for the common case in which
-   the third argument to x2nrealloc would be `sizeof (*P)'.
-   Ensure that sizeof (*P) is *not* 1.  In that case, it'd be
-   better to use X2REALLOC, although not strictly necessary.  */
-# define X2NREALLOC(P, PN) (VERIFY_EXPR (sizeof(*P) != 1), \
-                            x2nrealloc (P, PN, sizeof (*P)))
-
-/* Using x2realloc (when appropriate) usually makes your code more
-   readable than using x2nrealloc, but it also makes it so your
-   code will malfunction if sizeof (*P) ever becomes 2 or greater.
-   So use this macro instead of using x2realloc directly.  */
-# define X2REALLOC(P, PN) (VERIFY_EXPR (sizeof(*P) == 1), x2realloc (P, PN))
-
 /* Return 1 if an array of N objects, each of size S, cannot exist due
    to size arithmetic overflow.  S must be positive and N must be
    nonnegative.  This is a macro, not an inline function, so that it
Index: src/system.h
===================================================================
RCS file: /fetish/cu/src/system.h,v
retrieving revision 1.134
diff -p -u -r1.134 system.h
--- src/system.h        23 Aug 2005 15:05:54 -0000      1.134
+++ src/system.h        22 Sep 2005 06:25:10 -0000
@@ -513,6 +513,20 @@ uid_t getuid ();
 #endif
 
 #include "xalloc.h"
+#include "verify.h"
+
+/* This is simply a shorthand for the common case in which
+   the third argument to x2nrealloc would be `sizeof *(P)'.
+   Ensure that sizeof *(P) is *not* 1.  In that case, it'd be
+   better to use X2REALLOC, although not strictly necessary.  */
+#define X2NREALLOC(P, PN) (verify_expr (sizeof *(P) != 1), \
+                          x2nrealloc (P, PN, sizeof *(P)))
+
+/* Using x2realloc (when appropriate) usually makes your code more
+   readable than using x2nrealloc, but it also makes it so your
+   code will malfunction if sizeof *(P) ever becomes 2 or greater.
+   So use this macro instead of using x2realloc directly.  */
+#define X2REALLOC(P, PN) (verify_expr (sizeof *(P) == 1), x2realloc (P, PN))
 
 #if ! defined HAVE_MEMPCPY && ! defined mempcpy
 /* Be CAREFUL that there are no side effects in N.  */
@@ -585,7 +599,6 @@ enum
   _("      --version  output version information and exit\n")
 
 #include "closeout.h"
-#include "verify.h"
 #include "version-etc.h"
 
 #define case_GETOPT_VERSION_CHAR(Program_name, Authors)                        
\