diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/xalloc.h | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/lib/xalloc.h b/lib/xalloc.h index f80977e30..b743d6843 100644 --- a/lib/xalloc.h +++ b/lib/xalloc.h @@ -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 Free Software Foundation, Inc. + 1999, 2000, 2003, 2004, 2005 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 @@ -56,6 +56,24 @@ void *x2nrealloc (void *p, size_t *pn, size_t 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 |