/* Compile-time assert-like macros.
- Copyright (C) 2005-2006, 2009-2011 Free Software Foundation, Inc.
+ Copyright (C) 2005-2006, 2009-2013 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
# define _GL_VERIFY_H
-/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert works as per the
- C1X draft N1548 section 6.7.10. This is supported by GCC 4.6.0 and
- later, in C mode, and its use here generates easier-to-read diagnostics
- when verify (R) fails.
+/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert works as per C11.
+ This is supported by GCC 4.6.0 and later, in C mode, and its use
+ here generates easier-to-read diagnostics when verify (R) fails.
- Define _GL_HAVE_STATIC_ASSERT to 1 if static_assert works as per the
- C++0X draft N3242 section 7.(4).
+ Define _GL_HAVE_STATIC_ASSERT to 1 if static_assert works as per C++11.
This will likely be supported by future GCC versions, in C++ mode.
Use this only with GCC. If we were willing to slow 'configure'
extern int (*dummy (void)) [sizeof (struct {...})];
* GCC warns about duplicate declarations of the dummy function if
- -Wredundant_decls is used. GCC 4.3 and later have a builtin
+ -Wredundant-decls is used. GCC 4.3 and later have a builtin
__COUNTER__ macro that can let us generate unique identifiers for
each dummy function, to suppress this warning.
which do not support _Static_assert, also do not warn about the
last declaration mentioned above.
+ * GCC warns if -Wnested-externs is enabled and verify() is used
+ within a function body; but inside a function, you can always
+ arrange to use verify_expr() instead.
+
* In C++, any struct definition inside sizeof is invalid.
Use a template type to work around the problem. */
trailing ';'. If R is false, fail at compile-time, preferably
with a diagnostic that includes the string-literal DIAGNOSTIC.
- Unfortunately, unlike C1X, this implementation must appear as an
+ Unfortunately, unlike C11, this implementation must appear as an
ordinary declaration, and cannot appear inside struct { ... }. */
# ifdef _GL_HAVE__STATIC_ASSERT
# define _Static_assert(R, DIAGNOSTIC) _GL_VERIFY (R, DIAGNOSTIC)
# endif
# if !defined _GL_HAVE_STATIC_ASSERT && !defined static_assert
-# define static_assert _Static_assert /* Draft C1X requires this #define. */
+# define static_assert _Static_assert /* C11 requires this #define. */
# endif
# endif
contexts, e.g., the top level. */
/* Verify requirement R at compile-time, as an integer constant expression.
- Return 1. */
+ Return 1. This is equivalent to verify_expr (R, 1).
+
+ verify_true is obsolescent; please use verify_expr instead. */
# define verify_true(R) _GL_VERIFY_TRUE (R, "verify_true (" #R ")")
+/* Verify requirement R at compile-time. Return the value of the
+ expression E. */
+
+# define verify_expr(R, E) \
+ (_GL_VERIFY_TRUE (R, "verify_expr (" #R ", " #E ")") ? (E) : (E))
+
/* Verify requirement R at compile-time, as a declaration without a
trailing ';'. */